21 CFR 892.1660 - Non-image-intensified fluoroscopic x-ray system.

Science.gov (United States)

2010-04-01

... fluoroscopic x-ray system. (a) Identification. A non-image-intensified fluoroscopic x-ray system is a device... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Non-image-intensified fluoroscopic x-ray system... display equipment, patient and equipment supports, component parts, and accessories. (b) Classification...

Signal-to-noise characterization of time-gated intensifiers used for wide-field time-domain FLIM

Energy Technology Data Exchange (ETDEWEB)

McGinty, J; Requejo-Isidro, J; Munro, I; Talbot, C B; Dunsby, C; Neil, M A A; French, P M W [Photonics Group, Blackett Laboratory, Imperial College London, Prince Consort Road, London, SW7 2BW (United Kingdom); Kellett, P A; Hares, J D, E-mail: james.mcginty@imperial.ac.u [Kentech Instruments Ltd, Isis Building, Howbery Park, Wallingford, OX10 8BA (United Kingdom)

2009-07-07

Time-gated imaging using gated optical intensifiers provides a means to realize high speed fluorescence lifetime imaging (FLIM) for the study of fast events and for high throughput imaging. We present a signal-to-noise characterization of CCD-coupled micro-channel plate gated intensifiers used with this technique and determine the optimal acquisition parameters (intensifier gain voltage, CCD integration time and frame averaging) for measuring mono-exponential fluorescence lifetimes in the shortest image acquisition time for a given signal flux. We explore the use of unequal CCD integration times for different gate delays and show that this can improve the lifetime accuracy for a given total acquisition time.

Self-triggered image intensifier tube for high-resolution UHECR imaging detector

CERN Document Server

Sasaki, M; Jobashi, M

2003-01-01

The authors have developed a self-triggered image intensifier tube with high-resolution imaging capability. An image detected by a first image intensifier tube as an electrostatic lens with a photocathode diameter of 100 mm is separated by a half-mirror into a path for CCD readout (768x494 pixels) and a fast control to recognize and trigger the image. The proposed system provides both a high signal-to-noise ratio to improve single photoelectron detection and excellent spatial resolution between 207 and 240 mu m rendering this device a potentially essential tool for high-energy physics and astrophysics experiments, as well as high-speed photography. When combined with a 1-arcmin resolution optical system with 50 deg. field-of-view proposed by the present authors, the observation of ultra high-energy cosmic rays and high-energy neutrinos using this device is expected, leading to revolutionary progress in particle astrophysics as a complementary technique to traditional astronomical observations at multiple wave...

A self triggered intensified Ccd (Stic)

International Nuclear Information System (INIS)

Charon, Y.; Laniece, P.; Bendali, M.

1990-01-01

We are developing a new device based on the results reported previously of the successfull coincidence detection of β- particles with a high spatial resolution [1]. The novelty of the device consists in triggering an intensified CCD, i.e. a CCD coupled to an image intensifier (II), by an electrical signal collected from the II itself. This is a suitable procedure for detecting with high efficiency and high resolution low light rare events. The trigger pulse is obtained from the secondary electrons produced by multiplication in a double microchannel plate (MCP) and collected on the aluminized layer protecting the phosphor screen in the II. Triggering efficiencies up to 80% has been already achieved

An alternative approach to contrast-detail testing of X-ray image intensifier systems

International Nuclear Information System (INIS)

Kotre, C.J.; Marshall, N.W.; Faulkner, K.

1992-01-01

The difficulties of making the results of threshold contrast-detail diameter tests on X-ray image intensifier systems consistent with published performance standards are discussed. The current approach to contrast-detail testing is described and an alternative method intended to give greater consistency for all image intensifier input field diameters proposed. The current and alternative test conditions are compared on two image intensifier systems. The results obtained show that the contrast-detail curves for image intensifier systems with a wide range of input field diameters can be effectively normalized to be directly comparable to a common reference standard by applying the proposed alternative test conditions. The implications of this result on the interpretation of the contrast-detail test are discussed. (author)

Pick up screens for x-ray image intensifier tubes employing evaporated activated scintillator layer

International Nuclear Information System (INIS)

Spicer, W.E.

1976-01-01

The present invention relates in general to methods for making pick-up screens for x-ray image intensifier tubes and, more particularly, to an improved method wherein the x-ray fluorescent phosphor screen element is formed by evaporation of an alkali metal halide material in vacuum and condensing the evaporated material on an x-ray transparent portion of the x-ray intensifier tube, whereby a curved x-ray image pick-up screen is formed which has improved quantum efficiency and resolution. Such improved x-ray image intensifier tubes are especially useful for, but not limited in use to x-ray systems and for intensifying gamma ray images obtained in applications of nuclear medicine. 7 claims, 5 drawing figures

State of development and development trends of X-ray image intensifier television systems

International Nuclear Information System (INIS)

Pfeiler, M.; Haendle, J.

1975-01-01

Following a survey on the development of X-ray image intensifier television systems up to now, their further development is critically discussed with regard to the better image quality to be expected. The introduction of the high-resolving X-ray image intensifier already meant an improvement in image quality even though the television system remained the same. In the image intensifier television system, the distinguishability of small details suffers from noise effects. Therefore, a better image quality is especially advantageous in those ranges of application which allow a higher picture dose. 'Electronic' radiography, intermittent screening, co-storage of the spotfilm radiographs, videometry, video area kymography, and cardiac stroboscopy are examples some of which have already been tested in clinical practice. (orig./AK) [de

X-ray image intensifier/television systems for digital skeletal radiography

International Nuclear Information System (INIS)

Rowlands, J.A.; Hynes, D.M.; Edmonds, E.W.; Porter, A.J.; Toth, B.J.

1987-01-01

The imaging criteria for skeletal radiography (high resolution and low noise) relevant to the use of x-ray image intensifier/TV digital systems are discussed. It is shown from the modulation transfer function (MTF), noise, and phantom evaluations that conventional x-ray image intensifiers in conjunction with a 1,000-line Plumbicon or Saticon TV camera are in most respects suitable for skeletal radiography. The optimum focal spot size depends on a trade-off with motion blurring through the x-ray exposure time and so is a function of the clinical problem. Since the skeletal system is readily immobilized, a 0.3-mm focal spot size is nearly optimum

Achieving interlocking nails without using an image intensifier.

Science.gov (United States)

Ikem, Innocent C; Ogunlusi, Johnson D; Ine, Henry R

2007-08-01

Interlocking nails are commonly performed using an image intensifier. These are expensive and are not readily available in most resource-poor countries of the world. The aim of this study was to achieve interlocking nailing without the use of an image intensifier. This is a prospective descriptive analysis of 40 consecutive cases seen with shaft fractures of the humerus, femur, and tibia. Fracture fixation was done using Surgical Implant Generation Network (SIGN) nails. Forty limbs in 34 patients were studied. There were 12 females and 22 males, giving a ratio of 1:2. The mean age (years) was 35.75+/-13.16 and the range was 17-70 years. The studied bones were: humerus 10%, femur 65%, and tibia 25%. The fracture lines were: transverse 40%, oblique 15%, and communited 45%. Fracture grades were: closed 90%, grade I, 5%, grade II, 2.5%, and grade IIIA, 2.5%. Surgical approaches were: antegrade 62.5% and retrograde 37.5%. Indications for fixation were: recent fracture 92.5%, non-union 5%, and malunion 3%. Methods of reductions were: open 85% and closed 15%. The mean follow-up period (years) was 1.50+/-0.78. The union time averaged 3 months. Complication was mainly screw loosening due to severe osteoporoses in one case. It is, therefore, concluded that, with the aid of external jigs and slot finders, interlocking can be achieved without an image intensifier.

Fabry-Perot interferometry using an image-intensified rotating-mirror streak camera

International Nuclear Information System (INIS)

Seitz, W.L.; Stacy, H.L.

1983-01-01

A Fabry-Perot velocity interferometer system is described that uses a modified rotating mirror streak camera to recrod the dynamic fringe positions. A Los Alamos Model 72B rotating-mirror streak camera, equipped with a beryllium mirror, was modified to include a high aperture (f/2.5) relay lens and a 40-mm image-intensifier tube such that the image normally formed at the film plane of the streak camera is projected onto the intensifier tube. Fringe records for thin (0.13 mm) flyers driven by a small bridgewire detonator obtained with a Model C1155-01 Hamamatsu and Model 790 Imacon electronic streak cameras are compared with those obtained with the image-intensified rotating-mirror streak camera (I 2 RMC). Resolution comparisons indicate that the I 2 RMC gives better time resolution than either the Hamamatsu or the Imacon for total writing times of a few microseconds or longer

Correction method and software for image distortion and nonuniform response in charge-coupled device-based x-ray detectors utilizing x-ray image intensifier

International Nuclear Information System (INIS)

Ito, Kazuki; Kamikubo, Hironari; Yagi, Naoto; Amemiya, Yoshiyuki

2005-01-01

An on-site method of correcting the image distortion and nonuniform response of a charge-coupled device (CCD)-based X-ray detector was developed using the response of the imaging plate as a reference. The CCD-based X-ray detector consists of a beryllium-windowed X-ray image intensifier (Be-XRII) and a CCD as the image sensor. An image distortion of 29% was improved to less than 1% after the correction. In the correction of nonuniform response due to image distortion, subpixel approximation was performed for the redistribution of pixel values. The optimal number of subpixels was also discussed. In an experiment with polystyrene (PS) latex, it was verified that the correction of both image distortion and nonuniform response worked properly. The correction for the 'contrast reduction' problem was also demonstrated for an isotropic X-ray scattering pattern from the PS latex. (author)

The image intensifier in oral and maxillofacial surgery

International Nuclear Information System (INIS)

Gans, B.J.; Kallal, R.H.; Helgerson, A.C.; Verona, S.R.

1982-01-01

The mobile image intensifier has been found useful in the removal of foreign bodies from both intraoral and extraoral sites. The safety of the machine has been verified, and a technique for its application is described. Additional uses for the machine are stated

[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.

X-ray image intensifier tube and radiographic camera incorporating same

International Nuclear Information System (INIS)

1981-01-01

An X-ray sensitive image intensifier tube is described. It has an input window comprising at least one of iron, chromium and nickel for receiving an X-ray image. There is a flat scintillator screen adjacent for converting the X-ray image into a light pattern image. Adjacent to this is a flat photocathode layer for emitting photoelectrons in a pattern corresponding to the light pattern image. Parallel to this and spaced from it is a flat phosphor display screen. Electrostatic voltage is applied to the display screen and the photocathode layer to create an electric field between them to accelerate the photoelectrons towards the display screen. The paths of such parallel straight trajectories are governed solely by the electrostatic voltage applied, the image at the display screen being substantially equal in size to that of the X-ray image received at the input window. The tube envelope is preferably metallic to enable the basic components to be kept at a neutral potential and avoid spurious emissions. A radiographic camera with such an intensifier tube is also described. (U.K.)

Advances in Gamma-Ray Imaging with Intensified Quantum-Imaging Detectors

Science.gov (United States)

Han, Ling

Nuclear medicine, an important branch of modern medical imaging, is an essential tool for both diagnosis and treatment of disease. As the fundamental element of nuclear medicine imaging, the gamma camera is able to detect gamma-ray photons emitted by radiotracers injected into a patient and form an image of the radiotracer distribution, reflecting biological functions of organs or tissues. Recently, an intensified CCD/CMOS-based quantum detector, called iQID, was developed in the Center for Gamma-Ray Imaging. Originally designed as a novel type of gamma camera, iQID demonstrated ultra-high spatial resolution (advancing this conceptually-proven gamma-ray imaging technology to make it ready for both preclinical and clinical applications. To start with, a Monte Carlo simulation of the key light-intensification device, i.e. the image intensifier, was developed, which revealed the dominating factor(s) that limit energy resolution performance of the iQID cameras. For preclinical imaging applications, a previously-developed iQID-based single-photon-emission computed-tomography (SPECT) system, called FastSPECT III, was fully advanced in terms of data acquisition software, system sensitivity and effective FOV by developing and adopting a new photon-counting algorithm, thicker columnar scintillation detectors, and system calibration method. Originally designed for mouse brain imaging, the system is now able to provide full-body mouse imaging with sub-350-micron spatial resolution. To further advance the iQID technology to include clinical imaging applications, a novel large-area iQID gamma camera, called LA-iQID, was developed from concept to prototype. Sub-mm system resolution in an effective FOV of 188 mm x 188 mm has been achieved. The camera architecture, system components, design and integration, data acquisition, camera calibration, and performance evaluation are presented in this work. Mounted on a castered counter-weighted clinical cart, the camera also features

High-speed videography combined with an x-ray image intensifier for dynamic radiography

International Nuclear Information System (INIS)

Bryant, L.E. Jr.

1983-01-01

The Spin Physics SP-2000 high-speed video system can be combined with an x-ray source, a dynamic event having internal (not directly visible) movement and an x-ray image intensifier to perform dynamic radiography. The cesium iodide input fluor and P-20 output fluor of the image intensifier have rapid decay to allow x-ray imaging up to 12,000 pictures per second. Applications of this technique include internal functioning of a compressor, turbulent-water action, and other mechanical actions

Development of a 3-dimensional CT using an image intensifier

International Nuclear Information System (INIS)

Toyofuku, Fukai

1992-01-01

A prototype of three-dimensional CT (Fluoroscopic CT) has been developed using an image intensifier as a two-dimensional X-ray detector. A patient on a rotating table is projected onto an image intensifier by a cone beam of X-ray from the X-ray tube. A total of 390 projection images covering 180 degrees are acquired in a single scan (13 sec) and stored on a digital frame recorder (512 x 256 x 8-bit x 480). The transverse axial images are reconstructed by using the usual CT reconstruction algorithm, while longitudinal section images such as sagittal, coronal, oblique, and panoramic images are obtained by directly back-projecting the filtered projection image onto the sections. The radiation exposure was measured with an ionization chamber, and the exposure of the present fluoroscopic CT is about 10 to 20 times less than that of conventional X-ray CT. A similar monochromatic X-ray CT system has also been developed using synchrotron radiation. Large area parallel X-rays are obtained from a wiggler beam using a silicon crystal with [311] asymmetric reflection. By taking two images above and below iodine K-absorption edge (33.17 keV), iodine image is obtained. (author)

Multiple event 2D image intensifier scintillation detector

International Nuclear Information System (INIS)

Thieberger, P.; Wegner, H.E.; Lee, R.C.

1981-01-01

An image intensifier scintillation detector has been developed for the simultaneous detection of multiple light or heavy ions down to very low energies. The relative X-Y positions of each ion are read out by digitization of a television image of the light amplified scintillations. The maximum data rate is limited by the present television scan speed to 15 multiple events per second and to about one event second by the microcomputer presently used to store and process the data. (orig.)

Cheap streak camera based on the LD-S-10 intensifier tube

Science.gov (United States)

Dashevsky, Boris E.; Krutik, Mikhail I.; Surovegin, Alexander L.

1992-01-01

Basic properties of a new streak camera and its test results are reported. To intensify images on its screen, we employed modular G1 tubes, the LD-A-1.0 and LD-A-0.33, enabling magnification of 1.0 and 0.33, respectively. If necessary, the LD-A-0.33 tube may be substituted by any other image intensifier of the LDA series, the choice to be determined by the size of the CCD matrix with fiber-optical windows. The reported camera employs a 12.5- mm-long CCD strip consisting of 1024 pixels, each 12 X 500 micrometers in size. Registered radiation was imaged on a 5 X 0.04 mm slit diaphragm tightly connected with the LD-S- 10 fiber-optical input window. Electrons escaping the cathode are accelerated in a 5 kV electric field and focused onto a phosphor screen covering a fiber-optical plate as they travel between deflection plates. Sensitivity of the latter was 18 V/mm, which implies that the total deflecting voltage was 720 V per 40 mm of the screen surface, since reversed-polarity scan pulses +360 V and -360 V were applied across the deflection plate. The streak camera provides full scan times over the screen of 15, 30, 50, 100, 250, and 500 ns. Timing of the electrically or optically driven camera was done using a 10 ns step-controlled-delay (0 - 500 ns) circuit.

Large-field image intensifiers versus conventional chest radiography: ROC study with simulated interstitial disease

International Nuclear Information System (INIS)

Winter, L.H.L.; Chakraborty, D.P.; Waes, P.F.G.M.

1988-01-01

Two image intensifier tubes have recently been introduced whose large imaging area makes them suitable for chest imaging (Phillips Pulmodiagnost TLX slit II and Siemens TX 57 large entrance field II). Both modalities present a 10 x 10-cm hard copy image to the radiologist. A receiver operating characteristic (ROC) curve study with simulated interstitial disease was performed to compare the image quality of these image intensifiers with conventional chest images. The relative ranking in terms of decreasing ROC areas was Siemens, conventional, and Philips. Compared with conventional imaging, none of the differences in ROC curve area were statistically significant at the 5% level

Neutron imaging plates

International Nuclear Information System (INIS)

Niimura, Nobuo

1995-01-01

Imaging plates have been used in the field of medical diagnosis since long ago, but their usefulness was verified as the two-dimensional detector for analyzing the X-ray crystalline structure of high bio molecules like protein, and they have contributed to the remarkable progress in this field. The great contribution is due to the excellent features, such as the detection efficiency of about 100%, the positional resolution smaller than 0.2 mm, the dynamic range of five digits, and the area of several hundreds mm square. The neutron imaging plates have not yet obtained the sufficient results. It was planned to construct the neutron diffractometer for biological matters, and to put imaging plate neutron detectors (IP-ND) to practical use as the detector. The research on the development of IP-NDs was carried out, and the IPp-NDs having the performance comparable with that for X-ray were able to be produced. Imaging plates are the integral type two-dimensional radiation detector using photostimulated luminescence matters, and their principle is explained. As to neutron imaging plates, the converter, neutron detection efficiency and the flight of secondary particles in photo-stimulated luminescence matters are described. As for the present state of development of neutron imaging plates, the IP-NDs made for trial, the dynamic range, the positional resolution, the detection efficiency and the kinds of converters, and the application of IP-NDs are reported. (K.I.)

Pseudo real-time coded aperture imaging system with intensified vidicon cameras

International Nuclear Information System (INIS)

Han, K.S.; Berzins, G.J.

1977-01-01

A coded image displayed on a TV monitor was used to directly reconstruct a decoded image. Both the coded and the decoded images were viewed with intensified vidicon cameras. The coded aperture was a 15-element nonredundant pinhole array. The coding and decoding were accomplished simultaneously during the scanning of a single 16-msec TV frame

Dynamic imaging with a triggered and intensified CCD camera system in a high-intensity neutron beam

International Nuclear Information System (INIS)

Vontobel, P.; Frei, G.; Brunner, J.; Gildemeister, A.E.; Engelhardt, M.

2005-01-01

When time-dependent processes within metallic structures should be inspected and visualized, neutrons are well suited due to their high penetration through Al, Ag, Ti or even steel. Then it becomes possible to inspect the propagation, distribution and evaporation of organic liquids as lubricants, fuel or water. The principle set-up of a suited real-time system was implemented and tested at the radiography facility NEUTRA of PSI. The highest beam intensity there is 2x10 7 cm -2 s -1 , which enables to observe sequences in a reasonable time and quality. The heart of the detection system is the MCP intensified CCD camera PI-Max with a Peltier cooled chip (1300x1340 pixels). The intensifier was used for both gating and image enhancement, where as the information was accumulated over many single frames on the chip before readout. Although, a 16-bit dynamic range is advertised by the camera manufacturers, it must be less due to the inherent noise level from the intensifier. The obtained result should be seen as the starting point to go ahead to fit the different requirements of car producers in respect to fuel injection, lubricant distribution, mechanical stability and operation control. Similar inspections will be possible for all devices with repetitive operation principle. Here, we report about two measurements dealing with the lubricant distribution in a running motorcycle motor turning at 1200rpm. We were monitoring the periodic stationary movements of piston, valves and camshaft with a micro-channel plate intensified CCD camera system (PI-Max 1300RB, Princeton Instruments) triggered at exactly chosen time points

Digital image intensifier radiography: A new diagnostic procedure in traumatology?

International Nuclear Information System (INIS)

Schmidt, C.; Deininger, H.K.; Staedtische Kliniken Darmstadt

1990-01-01

Digital image intensifier radiography visualises all traumatological changes of clinical relevance and can therefore be used in traumatology. However, the quality of conventional radiographs cannot be attained as yet. Radiation exposure is markedly reduced, and radiographs are obtained directly after exposure, so that this is an extremely rapid radiographic procedure. Images can be quickly transmitted by video cable to the relevant departments and working places. (orig.) [de

Improved fluorescent X-ray image intensifying screen

International Nuclear Information System (INIS)

Landeghem, W.K. van; Suys, A.R.

1981-01-01

An X-ray image intensifying screen is described, which includes at least one fluorescent layer comprising phosphor particles dispersed in a binder and on top of such layer a protective layer containing a crosslinked polymer mass obtained by an acid-catalyzed reaction of a polymer or mixture of polymers containing reactive hydrogen atoms and a cross-linking agent, the cross-linking agent being an organic compound containing a plurality of etherified N-methylol groups. Examples are given of appropriate polymers and cross-linking agents. (author)

12-inch x-ray image intensifier with thin metal input window

Energy Technology Data Exchange (ETDEWEB)

Obata, Yoshiharu; Anno, Hidero; Harao, Norio [Toshiba Corp., Kawasaki, Kanagawa (Japan)

1982-08-01

Borosilicate glass has been used for X-ray input window of image intensifiers (I.I.) up to now. Now two new types of 12-inch metal I.I., RT12301C and RT12302C, have been developed. They use convex 1-mm aluminum (instead of 5-mm borosilicate glass) for the input window. Adopting a high-performance penta-electronic lens and a new type of light guide CsI film, these intensifiers have greatly improved contrast, quantum detection efficiency (QDE) and resolution capability. In spite of low dosage, image quality equivalent to that in the conventional direct radiograph is obtained through combined use of the new-type 12-inch metal I.I. with 0.3-mm small-focal-spot X-ray tube. Great contribution to digital radiography is expected of this I.I.

Relationship between fatigue of generation II image intensifier and input illumination

Science.gov (United States)

Chen, Qingyou

1995-09-01

If there is fatigue for an image intesifier, then it has an effect on the imaging property of the night vision system. In this paper, using the principle of Joule Heat, we derive a mathematical formula for the generated heat of semiconductor photocathode. We describe the relationship among the various parameters in the formula. We also discuss reasons for the fatigue of Generation II image intensifier caused by bigger input illumination.

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...

X-ray image intensifier for cardiovascular diagnosis. Development of RTP 9203 B-P4 and evaluation of image quality

Energy Technology Data Exchange (ETDEWEB)

Obata, Y; Suzuki, A; Noji, T; Harao, N [Toshiba Corp., Kawasaki, Kanagawa (Japan)

1979-07-01

The high utility of 35-mm cine fluorography with high-quality X-ray image intensifier has recently been acknowledged in the field of cardiovascular diagnosis. The newly developed 9-inch dual-field X-ray image intensifier is particularly suitable for 35-mm cinefluorography. The main characteristics of this tube are the increased contrast, brightness and resolution of images and the reduced quantum noise. These characteristics are caused by the CsI input phosphor screen which has a ''light-guide effect'', a high-sensitivity photocathode and a dark output screen. The tube is equipped with a high-voltage power supply with high reliability.

Neutron radiography using neutron imaging plate

International Nuclear Information System (INIS)

Chankow, Nares; Wonglee, Sarinrat

2008-01-01

Full text: The aims of this research are to study properties of neutron imaging plate, to obtain a suitable condition for neutron radiography and to use the neutron imaging plate for testing of materials nondestructively. The experiments were carried out by using a neutron beam from the Thai Research Reactor TRR-1/M1 at a power of 1.2 MW. A BAS-ND 2040 FUJI neutron imaging plate and a MX125 Kodak X-ray film/Gadolinium neutron converter screen combination were tested for comparison. It was found that the photostimulated light (PSL) read out of the imaging plate was directly proportional to the exposure time. It was also found that radiography with neutron using the imaging plate was approximately 40 times faster than the conventional neutron radiography using x-ray film/Gd converter screen combination. The sensitivity of the imaging plate to gamma-rays was investigated by using gamma-rays from an 192 Ir and a 60 Co radiographic sources. The imaging plate was found to be 5-6 times less sensitive to gamma-rays than a FUJI BAS-MS 2040 gamma-ray imaging plate. Finally, some specimens were selected to be radiographed with neutrons using the imaging plate and the x-ray film/Gd converter screen combination in comparison to x-rays. Parts containing light elements could be clearly observed by the two neutron radiographic techniques. It could be concluded that the image quality from the neutron imaging plate was comparable to the conventional x-ray film/Gd converter screen combination but the exposure time could be approximately reduced by a factor of 40

A distortion correction method for image intensifier and electronic portal images used in radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Ioannidis, G T; Geramani, K N; Zamboglou, N [Strahlenklinik, Stadtische Kliniken Offenbach, Offenbach (Germany); Uzunoglu, N [Department of Electrical and Computer Engineering, National Technical University of Athens, Athens (Greece)

1999-12-31

At the most of radiation departments a simulator and an `on line` verification system of the treated volume, in form of an electronic portal imaging device (EPID), are available. Networking and digital handling (saving, archiving etc.) of the image information is a necessity in the image processing procedures in order to evaluate verification and simulation recordings at the computer screen. Distortion is on the other hand prerequisite for quantitative comparison of both image modalities. Another limitation factor, in order to make quantitative assertions, is the fact that the irradiation fields in radiotherapy are usually bigger than the field of view of an image intensifier. Several segments of the irradiation field must therefore be acquired. Using pattern recognition techniques these segments can be composed into a single image. In this paper a distortion correction method will be presented. The method is based upon a well defined Grid which is embedded during the registration process on the image. The video signal from the image intensifier is acquired and processed. The grid is then recognised using image processing techniques. Ideally if all grid points are recognised, various methods can be applied in order to correct the distortion. But in practice this is not the case. Overlapping structures (bones etc.) have as a consequence that not all of the grid points can be recognised. Mathematical models from the Graph theory are applied in order to reconstruct the whole grid. The deviation of the grid points positions from the rated value is then used to calculate correction coefficients. This method (well defined grid, grid recognition, correction factors) can also be applied in verification images from the EPID or in other image modalities, and therefore a quantitative comparison in radiation treatment is possible. The distortion correction method and the application on simulator images will be presented. (authors)

Examination of the lumbar vertebral column using large-screen image intensifier photofluorography

Energy Technology Data Exchange (ETDEWEB)

Soimakallio, S.; Manninen, H.; Mahlamaeki, S.

1985-01-01

The OPTILUX 57 device with its large image intensifying screen is very efficient in visualizing the lumbar vertebrae. The article explains the techniques and summarizes results obtained in the examination of young sportsmen.

Examination of the lumbar vertebral column using large-screen image intensifier photofluorography

International Nuclear Information System (INIS)

Soimakallio, S.; Manninen, H.; Mahlamaeki, S.; Kuopio Central Hospital

1985-01-01

The OPTILUX 57 device with its large image intensifying screen is very efficient in visualizing the lumbar vertebrae. The article explains the techniques and summarizes results obtained in the examination of young sportsmen. (orig.) [de

Quality control measurements of X-ray image-intensifier television chain systems

International Nuclear Information System (INIS)

Henshaw, E.T.

1989-01-01

The test methods and limiting values for the following basic parameters of an image intensifier TV system are presented in relation to (a) acceptance tests and (b) constancy tests: automatic gain and brightness control, video voltage output, monitor check (grey scale), geometric distortion, noise (low-contrast detectability), overall imaging ability, limiting resolution, uniformity of resolution, conversion factor, contrast ratio and measurement of field size. Several of these tests make use of the Leeds Test Objects. (author)

X-ray topography with scintillators coupled to image intensifiers or camera tubes

International Nuclear Information System (INIS)

Beauvais, Yves; Mathiot, Alain.

1978-01-01

The possibility of imaging topographic figures in real time by using a thin scintillator coupled to either a high-gain image intensifier or a camera tube is investigated. The camera tube must have a high gain because of the low photon fluxes that are encountered in practice, and because of the relatively low quantum yield of thin phosphors. With conventional X-ray generators, the resolution is photon-noise limited. With more powerful generators like synchrotrons, real-time imaging appears possible, and the resolution is limited by the modulation transfer function of the image tube. Higher resolution can be reached by increasing the magnification between the screen and the image tube. When doing so, the input field is reduced and thinner phosphor screens must be used, resulting in a lower yield. Each time the magnification is doubled, the minimum required photon flux is multiplier by about 8, so that the advantages of increasing the magnification are rapidly limited, so far as real-time imaging is concerned. Because image tube resolution is mainly limited by the modulation transfer function of the phosphor for image intensifiers, and by that of the target for camera tubes, improvement of photocathode resolution can be obtained by magnifying electron optics. A zooming electron optic would permit the field and the resolution of the tube to be adapted to the observed subject. Unfortunately such tubes do not exist at present for this type of application, and in the required size

Method and equipment for image intensifying in xeroradiography

International Nuclear Information System (INIS)

Jeromin, L.S.

1975-01-01

The xeroradiography or xeromammography uses, e.g. in mammography, a xerographic plate with an electrostatic charge. This charge reproduces a latent image of the part of the body irradiated with X-ray or γ-radiations. It is rendered visible by contacting with electrically oppositely charged, finely powdered particles. In order to be able to reduce the dose of radiation applied and to guarantee a sufficient contrasting, the latent image is, however, at first only partly exposed to a reduced radiation dose. After contacting with powder, the xerographic plate of an aluminum base with lead coating and the sensitive layer of amorphous or glazed selenium, is intermediately exposed to light. The final development is again carried out using powdered particles which lie on a higher voltage than those of the first contacting. (DG/LH) [de

A year's experience with a 57 cm image intensifier in a general X-ray room

International Nuclear Information System (INIS)

Georgi, M.; Prager, P.; Busch, H.P.; Strauss, L.; Wetzel, E.; Neumann, D.; Weiher, M.; Regenfuss, W.

1985-01-01

3342 patients were examined by means of a 57 cm image intensifier during one year. The installation permits examination with the patient standing or lying. The resolution was measured with a lead grid under conditions resembling actual practice and were found to be similar to those obtained with angiographic equipment. Using a medium format technique for examining the gut and vascular system resulted in radiographic quality which was not significantly different from the use of a large format technique. For examination of the skeleton, radiographic quality, using the intensifier, was markedly poorer than that resulting from Bucky examinations. There was no diagnostic difference when carrying out lymphograms. The large intensifier window of 53 cm was particularly advantageous for DSA of the pelvic and lower limb vessels when compared with smaller intensifiers. Possible savings of film and contrast medium costs are discussed. (orig.) [de

Performance assessment of imaging plates for the JHR transfer Neutron Imaging System

Science.gov (United States)

Simon, E.; Guimbal, P. AB(; )

2018-01-01

The underwater Neutron Imaging System to be installed in the Jules Horowitz Reactor (JHR-NIS) is based on a transfer method using a neutron activated beta-emitter like Dysprosium. The information stored in the converter is to be offline transferred on a specific imaging system, still to be defined. Solutions are currently under investigation for the JHR-NIS in order to anticipate the disappearance of radiographic films commonly used in these applications. We report here the performance assessment of Computed Radiography imagers (Imaging Plates) performed at LLB/Orphée (CEA Saclay). Several imaging plate types are studied, in one hand in the configuration involving an intimate contact with an activated dysprosium foil converter: Fuji BAS-TR, Fuji UR-1 and Carestream Flex XL Blue imaging plates, and in the other hand by using a prototypal imaging plate doped with dysprosium and thus not needing any contact with a separate converter foil. The results for these imaging plates are compared with those obtained with gadolinium doped imaging plate used in direct neutron imaging (Fuji BAS-ND). The detection performances of the different imagers are compared regarding resolution and noise. The many advantages of using imaging plates over radiographic films (high sensitivity, linear response, high dynamic range) could palliate its lower intrinsic resolution.

Development of an image intensifier-TV digital imaging system with a multiple-slit scanning x-ray beam

International Nuclear Information System (INIS)

Kume, Y.; Doi, K.

1986-01-01

The authors are developing a new digital x-ray imaging system employing a multiple-slit assembly (MSA) and an image intensifier (II)-TV digital system. The final image consisting of primary radiation is digitally reconstructed from multiple slit images obtained with the MSA. This system can significantly reduce the scattered radiation from an object and the veiling glare from II-TV system. The quality of the reconstructed image is related to many parameters, such as slit width, the number of image frames, and the image reconstruction algorithm. They present the effect of these various parameters on basic imaging properties and the practicability of the method in comparison with conventional wide beam imaging

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.

Application of ultra-fast high-resolution gated-image intensifiers to laser fusion studies

International Nuclear Information System (INIS)

Lieber, A.J.; Benjamin, R.F.; Sutphin, H.D.; McCall, G.H.

1975-01-01

Gated-image intensifiers for fast framing have found high utility in laser-target interaction studies. X-ray pinhole camera photographs which can record asymmetries of laser-target interactions have been instrumental in further system design. High-resolution high-speed x-ray images of laser irradiated targets are formed using pinhole optics and electronically amplified by proximity focused channelplate intensifiers before being recorded on film. Spectral resolution is obtained by filtering. In these applications shutter duration is determined by source duration. Electronic gating serves to reduce background thereby enhancing signal-to-noise ratio. Cameras are used to view the self light of the interaction but may also be used for shadowgraphs. Sources for shadowgraphs may be sequenced to obtain a series of pictures with effective rates of 10 10 frame/s. Multiple aperatures have been used to obtain stereo x-ray views, yielding three dimensional information about the interactions. (author)

X-ray image intensifier camera tubes and semiconductor targets

International Nuclear Information System (INIS)

1979-01-01

A semiconductor target for use in an image intensifier camera tube and a camera using the target are described. The semiconductor wafer for converting an electron image onto electrical signal consists mainly of a collector region, preferably n-type silicon. It has one side for receiving the electron image and an opposite side for storing charge carriers generated in the collector region by high energy electrons forming a charge image. The first side comprises a highly doped surface layer covered with a metal buffer layer permeable to the incident electrons and thick enough to dissipate some of the incident electron energy thereby improving the signal-to-noise ratio. This layer comprises beryllium on niobium on the highly doped silicon surface zone. Low energy Kα X-ray radiation is generated in the first layer, the radiation generated in the second layer (mainly Lα radiation) is strongly absorbed in the silicon layer. A camera tube using such a target with a photocathode for converting an X-ray image into an electron image, means to project this image onto the first side of the semiconductor wafer and means to read out the charge pattern on the second side are also described. (U.K.)

The construction and evaluation of a prototype system for an image intensifier-based volume computed tomography imager

International Nuclear Information System (INIS)

Ning, R.

1989-01-01

A volumetric reconstruction of a three-dimensional (3-D) object has been at the forefront of exploration in medical applications for a long time. To achieve this goal, a prototype system for an image intensifier(II)-based volume computed tomography (CT) imager has been constructed. This research has been concerned with constructing and evaluating such a prototype system by phantom studies. The prototype system consists of a fixed x-ray tube, a specially designed aluminum filter that will reduce the dynamic range of projection data, an antiscatter grid, a conventional image intensifier optically coupled to a charge-coupled device (CCC) camera, a computer controlled turntable on which phantoms are placed, a digital computer including an A/D converter and a graphic station that displays the reconstructed images. In this study, three different phantoms were used: a vascular phantom, a resolution phantom and a Humanoid reg-sign chest phantom. The direct 3-D reconstruction from the projections was performed using a cone beam algorithm and vascular reconstruction algorithms. The image performance of the system for the direct 3-D reconstruction was evaluated. The spatial resolution limits of the system were estimated through observing the reconstructed images of the resolution phantom. By observing the images reconstructed from the projections, it can be determined that the image performance of the prototype system for a direct 3-D reconstruction is reasonably good and that the vascular reconstruction algorithms work very well. The results also indicate that the 3-D reconstructions obtained with the 11-based volume CT imager have nearly equally good resolution in x, y and z directions and are superior to a conventional CT in the resolution of the z direction

Dynamic flat panel detector versus image intensifier in cardiac imaging: dose and image quality

Science.gov (United States)

Vano, E.; Geiger, B.; Schreiner, A.; Back, C.; Beissel, J.

2005-12-01

The practical aspects of the dosimetric and imaging performance of a digital x-ray system for cardiology procedures were evaluated. The system was configured with an image intensifier (II) and later upgraded to a dynamic flat panel detector (FD). Entrance surface air kerma (ESAK) to phantoms of 16, 20, 24 and 28 cm of polymethyl methacrylate (PMMA) and the image quality of a test object were measured. Images were evaluated directly on the monitor and with numerical methods (noise and signal-to-noise ratio). Information contained in the DICOM header for dosimetry audit purposes was also tested. ESAK values per frame (or kerma rate) for the most commonly used cine and fluoroscopy modes for different PMMA thicknesses and for field sizes of 17 and 23 cm for II, and 20 and 25 cm for FD, produced similar results in the evaluated system with both technologies, ranging between 19 and 589 µGy/frame (cine) and 5 and 95 mGy min-1 (fluoroscopy). Image quality for these dose settings was better for the FD version. The 'study dosimetric report' is comprehensive, and its numerical content is sufficiently accurate. There is potential in the future to set those systems with dynamic FD to lower doses than are possible in the current II versions, especially for digital cine runs, or to benefit from improved image quality.

Comparison of dose and image quality of a Flat-panel detector and an image intensifier

International Nuclear Information System (INIS)

Lazzaro, M.; Friedrich, B.Q.; Luz, R.M. da; Silva, A.M.M. da

2016-01-01

With the development of new technologies, have emerged new conversion methods of X-ray image, such as flat panel detectors. The aim of this work is the comparison of entrance surface air kerma (ESAK) and image quality between an image intensifier type of detector (A) and a flat panel (B). The ESAK was obtained by placing a ionization chamber under PMMA simulators of 10, 20 and 30 cm and the image quality was obtained by using the TOR "1"8FG simulator. The ESAK to the equipment A is higher when compared to the equipment B. The high contrast resolution is better for the equipment A for all thicknesses of simulators. The equipment A has low contrast resolution with a better viewing threshold for thicknesses of 10 and 20 cm, and a worse performance for 30 cm. It is concluded that the equipment B has ESAK smaller and despite having lower resolution, in almost all cases, have appropriate image quality for diagnosis. (author)

Non-destructive evaluation utilizing imaging plates for field radiography applications

International Nuclear Information System (INIS)

White, Brian S.

2016-01-01

The oil and gas industry has utilized film radiography for the evaluation of pipeline welds for many years. The world has evolved, and today people are easily sharing digital images as part of the information revolution. Computed radiography is ready to replace film radiography for portable outdoor use applications. Computed radiography technology adoption has been contingent upon achieving acceptable image quality and getting enough imaging plate use cycles to be profitable. Image quality is dependent upon shot conditions, imaging plate type, reader settings, and scatter control. Likewise, the number of achievable use cycles is dependent upon the imaging plate design for durability and the user's operating environment. This presentation reviews the basic principles of storage phosphor imaging plates. Usage criteria and guidelines for optimum image quality and maximized overall use cycles will be discussed for various imaging plate types. A comparison of film and computed radiography imaging plate technology will be presented.

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.

Evaluating Picture Quality of Image Plates in Digital CR Systems

International Nuclear Information System (INIS)

Kwak, Byung Joon; Ji Tae Jeong

2011-01-01

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.

The visible intensified cameras for plasma imaging in the TJ-II stellarator

International Nuclear Information System (INIS)

Cal, E. de la; Carralero, D.; Pablos, J.L. de; Alonso, A.; Rios, L.; Garcia Sanchez, P.; Hidalgo, C.

2011-01-01

Visible cameras are widely used in fusion experiments for diagnosis and for machine safety issues. They are generally used to monitor the plasma emission, but are also sensible to surface Blackbody radiation and Bremsstrahlung. Fast or high speed cameras capable of operating in the 10 5 frames per second speed range are today commercially available and offer the opportunity to plasma fusion researchers of two-dimensional (2D) imaging of fast phenomena such as turbulence, ELMs, disruptions, dust, etc. The tracking of these fast phenomena requires short exposure times down to the μ s range and the light intensity can be often near the signal to noise ratio limit especially in low plasma emission regions such as the far SOL Additionally, when using interference filters to monitor, e.g. impurity line emission, the photon flux is strongly reduced and the emission cannot be imaged at high speed. Therefore, the use of image intensifiers that amplify the light intensity onto the camera sensor can be of great help. The present work describes the use of intensifiers in the visible fast cameras of TJ-II stellarator. We have achieved spectroscopic plasma imaging of filtered impurity atomic line emission at short exposure times down to the 10 μ s range depending on atomic line and concentration. Additionally, plasma movies at velocities of 2x10 5 frames per second near the camera operation limit can be recorded with exposure times well below 1 μ s with sufficient signal to noise ratio. Although an increasing degradation of the image quality appears when raising the light amplification, an effective gain of up to two orders of magnitude of the light intensity is feasible for many applications (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

The visible intensified cameras for plasma imaging in the TJ-II stellarator

Energy Technology Data Exchange (ETDEWEB)

Cal, E. de la; Carralero, D.; Pablos, J.L. de; Alonso, A.; Rios, L.; Garcia Sanchez, P.; Hidalgo, C. (Laboratorio Nacional de Fusion, Asociacion Euratom-Ciemat, Av. Complutense 22, E-28040 Madrid)

2011-09-15

Visible cameras are widely used in fusion experiments for diagnosis and for machine safety issues. They are generally used to monitor the plasma emission, but are also sensible to surface Blackbody radiation and Bremsstrahlung. Fast or high speed cameras capable of operating in the 10{sup 5} frames per second speed range are today commercially available and offer the opportunity to plasma fusion researchers of two-dimensional (2D) imaging of fast phenomena such as turbulence, ELMs, disruptions, dust, etc. The tracking of these fast phenomena requires short exposure times down to the {mu} s range and the light intensity can be often near the signal to noise ratio limit especially in low plasma emission regions such as the far SOL Additionally, when using interference filters to monitor, e.g. impurity line emission, the photon flux is strongly reduced and the emission cannot be imaged at high speed. Therefore, the use of image intensifiers that amplify the light intensity onto the camera sensor can be of great help. The present work describes the use of intensifiers in the visible fast cameras of TJ-II stellarator. We have achieved spectroscopic plasma imaging of filtered impurity atomic line emission at short exposure times down to the 10 {mu} s range depending on atomic line and concentration. Additionally, plasma movies at velocities of 2x10{sup 5} frames per second near the camera operation limit can be recorded with exposure times well below 1 {mu} s with sufficient signal to noise ratio. Although an increasing degradation of the image quality appears when raising the light amplification, an effective gain of up to two orders of magnitude of the light intensity is feasible for many applications (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Large-image intensifier photofluorography and conventional radiography in pulmonary emphysema

International Nuclear Information System (INIS)

Manninen, H.; Partanen, K.; Soimakallio, S.; Rytkoenen, H.

1988-01-01

Large-screen image intensifier (II) photofluorography was compared with full-size screen-film chest radiography in the diagnosis of pulmonary emphysema in 84 patients. Photospot films and conventional radiographs were interpreted independently by three radiologists. Computed tomography (CT) was used as an independent reference technique, and diagnostic performance of chest radiography in various CT patterns of emphysema was evaluated. The difference in diagnostic sensitivity for emphysema in favor of conventional chest radiography over photofluorography (0.65 versus 0.56) was statistically significant (p < 0.05). Specificity of the imaging modalities was equal: 0.78 in full-size films and 0.77 in photospot films. All CT patterns of emphysema had great false negative response rates in chest radiography, which is an inaccurate technique for the diagnosis of emphysema. CT is required for reliable radiologic evaluation of emphysema. (orig.)

Measurement of the uniformity of X-ray image-intensifier television systems and of the system components

International Nuclear Information System (INIS)

Cooney, P.; Maher, K.P.; Malone, J.F.

1989-01-01

This paper presents work on the use of the National Electrical Manufacturers' Association definition of uniformity for gamma cameras and its refinement for application in the field with image intensified television (II-TV) chains as whole systems. Methods of measurement employed using on-site high-quality videotape recording combined with an off-site and off-line digital image processor are described. Impact of noise reduction and matrix size on the results is outlined. The contribution of individual components of the chain to the non-uniformity have also been assessed in detail using methods of measurement and definitions specifically developed to be suitable for application in the hospital environment by an experienced physicist. The methods and results for (i) the X-ray beam, (ii) the image intensifier and (iii) the TV system are presented. These methods have been tested by applying them to a sample of 10 II-TV systems in routine hospital use and results are reported. (author)

Assessment of uniformity and signal-to-noise ratio in radiological image intensifier TV systems

International Nuclear Information System (INIS)

Malone, J.F.; O'Connor, M.K.; Maher, K.P.

1985-01-01

A method of measuring the uniformity of radiological Image Intensifier-TV systems is described. Large non-uniformities were observed in the systems tested. A method of estimating the Signal-to-Noise Ratio in such systems is also presented and applied to characterise the effectiveness of the noise reduction techniques used in digital fluoroscopy. (author)

Characterization study of an intensified complementary metal-oxide-semiconductor active pixel sensor

Science.gov (United States)

Griffiths, J. A.; Chen, D.; Turchetta, R.; Royle, G. J.

2011-03-01

An intensified CMOS active pixel sensor (APS) has been constructed for operation in low-light-level applications: a high-gain, fast-light decay image intensifier has been coupled via a fiber optic stud to a prototype "VANILLA" APS, developed by the UK based MI3 consortium. The sensor is capable of high frame rates and sparse readout. This paper presents a study of the performance parameters of the intensified VANILLA APS system over a range of image intensifier gain levels when uniformly illuminated with 520 nm green light. Mean-variance analysis shows the APS saturating around 3050 Digital Units (DU), with the maximum variance increasing with increasing image intensifier gain. The system's quantum efficiency varies in an exponential manner from 260 at an intensifier gain of 7.45 × 103 to 1.6 at a gain of 3.93 × 101. The usable dynamic range of the system is 60 dB for intensifier gains below 1.8 × 103, dropping to around 40 dB at high gains. The conclusion is that the system shows suitability for the desired application.

Micro-channel plates and vacuum detectors

Energy Technology Data Exchange (ETDEWEB)

Gys, T., E-mail: Thierry.Gys@cern.ch

2015-07-01

A micro-channel plate is an array of miniature electron multipliers that are each acting as a continuous dynode chain. The compact channel structure results in high spatial and time resolutions and robustness to magnetic fields. Micro-channel plates have been originally developed for night vision applications and integrated as an amplification element in image intensifiers. These devices show single-photon sensitivity with very low noise and have been used as such for scintillating fiber tracker readout in high-energy physics experiments. Given their very short transit time spread, micro-channel plate photomultiplier tubes are also being used in time-of-flight and particle identification detectors. The present paper will cover the history of the micro-channel plate development, basic features, and some of their applications. Emphasis will be put on various new manufacturing processes that have been developed over the last few years, and that result in a significant improvement in terms of efficiency, noise, and lifetime performance.

Star tracking method based on multiexposure imaging for intensified star trackers.

Science.gov (United States)

Yu, Wenbo; Jiang, Jie; Zhang, Guangjun

2017-07-20

The requirements for the dynamic performance of star trackers are rapidly increasing with the development of space exploration technologies. However, insufficient knowledge of the angular acceleration has largely decreased the performance of the existing star tracking methods, and star trackers may even fail to track under highly dynamic conditions. This study proposes a star tracking method based on multiexposure imaging for intensified star trackers. The accurate estimation model of the complete motion parameters, including the angular velocity and angular acceleration, is established according to the working characteristic of multiexposure imaging. The estimation of the complete motion parameters is utilized to generate the predictive star image accurately. Therefore, the correct matching and tracking between stars in the real and predictive star images can be reliably accomplished under highly dynamic conditions. Simulations with specific dynamic conditions are conducted to verify the feasibility and effectiveness of the proposed method. Experiments with real starry night sky observation are also conducted for further verification. Simulations and experiments demonstrate that the proposed method is effective and shows excellent performance under highly dynamic conditions.

Lead foil in dental X-ray film: Backscattering rejection or image intensifier?

International Nuclear Information System (INIS)

Hönnicke, M.G.; Delben, G.J.; Godoi, W.C.; Swinka-Filho, V.

2014-01-01

Dental X-ray films are still largely used due to sterilization issues, simplicity and, mainly, economic reasons. These films almost always are double coated (double emulsion) and have a lead foil in contact with the film for X-ray backscattering rejection. Herein we explore the use of the lead foil as an image intensifier. In these studies, spatial resolution was investigated when images were acquired on the dental X-ray films with and without the lead foil. Also, the lead foil was subjected to atomic analysis (fluorescent measurements) and structure analysis (X-ray diffraction). We determined that the use of the lead foil reduces the exposure time, however, does not affect the spatial resolution on the acquired images. This suggests that the fluorescent radiation spread is smaller than the grain sizes of the dental X-ray films

Lead foil in dental X-ray film: Backscattering rejection or image intensifier?

Science.gov (United States)

Hönnicke, M. G.; Delben, G. J.; Godoi, W. C.; Swinka-Filho, V.

2014-11-01

Dental X-ray films are still largely used due to sterilization issues, simplicity and, mainly, economic reasons. These films almost always are double coated (double emulsion) and have a lead foil in contact with the film for X-ray backscattering rejection. Herein we explore the use of the lead foil as an image intensifier. In these studies, spatial resolution was investigated when images were acquired on the dental X-ray films with and without the lead foil. Also, the lead foil was subjected to atomic analysis (fluorescent measurements) and structure analysis (X-ray diffraction). We determined that the use of the lead foil reduces the exposure time, however, does not affect the spatial resolution on the acquired images. This suggests that the fluorescent radiation spread is smaller than the grain sizes of the dental X-ray films.

Volar plating for distal radius fractures--do not trust the image intensifier when judging distal subchondral screw length.

Science.gov (United States)

Park, Derek H; Goldie, Boyd S

2012-09-01

The use of the volar plate to treat distal radius fractures is increasing but despite the theoretical advantages of a volar approach there have been reports of extensor tendon ruptures due to prominent screw tips protruding past the dorsal cortex. The valley in the intermediate column between Lister tubercle and the sigmoid notch of the distal radius makes it difficult to rely on fluoroscopy to judge screw length. Our aim was to quantify the dimensions of this valley and to demonstrate the danger of relying on intraoperative image intensification fluoroscopy to determine lengths of distal screws. We measured the depth of this valley in the intermediate column of the distal radius in 33 patients with computed tomographic (9 patients) or magnetic resonance image (24 patients) scans of the wrist. There was a consistent valley in all images examined [average 1.8 mm (95% confidence interval, 1.6-2.0 mm)]. Thirty-nine percent of wrists had a valley depth of at least 2 mm. Standard lateral views or rotation of the forearm to obtain oblique views does not identify prominent screw tips; and whatever the rotation of the forearm, screw tips protruding beyond dorsal cortex may look as if it is within the bone when in fact it is out. When drilling we suggest noting the depth at which the drill bit just penetrates dorsal cortex and routinely downsize the distal screw length by 2 mm. We caution against relying on flourosocopy when judging the length of the distal subchondral screws.

Measurement and monitoring of entrance exposure dose rate in X-ray image intensifier television with dose rate control

Energy Technology Data Exchange (ETDEWEB)

Klein, J [Bezirkskrankenhaus Brandenburg (German Democratic Republic)

1981-03-01

For X-ray image intensifier television operation very low entrance dose rates (about 5.2 nA/kg) are stated and demanded, respectively. These required values are often manifold exceeded in practice so that a check seems to be necessary. It is shown and proved how these measurements can be performed with simple, generally available means of measurement in the radiological practice. For ZnCdS-image intensifiers should be considered that about 13 nA/kg for the large entrance size are not to be exceeded; for the CsI type lower values (factor 1.5) are practicable because of the twofold quantum absorption efficiency. Furthermore, some tests for a semiquantitative function check of the automatic dose rate control are proposed.

Measurement of the uniformity of X-ray image-intensifier television systems and of the system components

International Nuclear Information System (INIS)

Cooney, P.; Maher, K.P.; Malone, J.F.

1989-01-01

Uniformity is a well defined term used to describe the response of a gamma camera to a ''uniform'' radiation input. A similar quantity is required in the specification of the image-intensifier (II) television (TV) chains used in fluoroscopic imaging, particularly in vascular, cardiac and digital applications. This paper presents work on the use of the National Electrical Manufacturers' Association definition of uniformity for gamma cameras and its refinement for application in the field with II-TV chains as whole systems. The methods of measurement employed using on-site high-quality videotape recording combined with an off-site and off-line digital image processor are described. The impact of noise reduction and matrix size on the results in outlined. The contribution of individual components of the chain to the non-uniformity have also been assessed in detail using methods of measurement and definitions specifically developed to be suitable for application in the hospital environment by an experienced physicist. The methods and results for (i) the X-ray beam, (ii) the image intensifier and (iii) the TV system are presented. These methods have been tested by applying them to a sample of 10 II-TV systems in routine hospital use and the results are reported. (author)

Quality control of image-intensifier television chains in Finland

International Nuclear Information System (INIS)

Pirinen, M.

1989-01-01

There are some 500 image-intensifier television (TV) chains connected to fluoroscopic units in Finland, most installed in the 1970s, although the oldest still in use date back to the late 1960s. To establish performance levels of the chains, 300 of them were assessed in 1982 by the Finnish Centre for Radiation and Nuclear Safety (STUK). Results showed great diversity in the condition of the chains. The main reason was lack of periodical quality assurance of the chains. Recommendations for limits were established from results of assessing three parameters describing the condition of the chains: spatial resolution, automatically controlled dose-rate and contrast sensitivity. Recommendations also advise hospitals on how to arrange alternative quality assurance measurements and observations, either by hospital's maintenance staff, the manufacturer, or the supervising authority (STUK). Results following adoption of the recommendations by hospitals are presented. (author)

Retrofit implementation of Zernike phase plate imaging for cryo-TEM.

Science.gov (United States)

Marko, Michael; Leith, Ardean; Hsieh, Chyongere; Danev, Radostin

2011-05-01

In-focus phase-plate imaging is particularly beneficial for cryo-TEM because it offers a substantial overall increase in image contrast, without an electron dose penalty, and it simplifies image interpretation. We show how phase-plate cryo-TEM can be implemented with an appropriate existing TEM, and provide a basic practical introduction to use of thin-film (carbon) phase plates. We point out potential pitfalls of phase-plate operation, and discuss solutions. We provide information on evaluating a particular TEM for its suitability. Copyright © 2011 Elsevier Inc. All rights reserved.

A reconfigurable image tube using an external electronic image readout

Science.gov (United States)

Lapington, J. S.; Howorth, J. R.; Milnes, J. S.

2005-08-01

We have designed and built a sealed tube microchannel plate (MCP) intensifier for optical/NUV photon counting applications suitable for 18, 25 and 40 mm diameter formats. The intensifier uses an electronic image readout to provide direct conversion of event position into electronic signals, without the drawbacks associated with phosphor screens and subsequent optical detection. The Image Charge technique is used to remove the readout from the intensifier vacuum enclosure, obviating the requirement for additional electrical vacuum feedthroughs and for the readout pattern to be UHV compatible. The charge signal from an MCP intensifier is capacitively coupled via a thin dielectric vacuum window to the electronic image readout, which is external to the sealed intensifier tube. The readout pattern is a separate item held in proximity to the dielectric window and can be easily detached, making the system easily reconfigurable. Since the readout pattern detects induced charge and is external to the tube, it can be constructed as a multilayer, eliminating the requirement for narrow insulator gaps and allowing it to be constructed using standard PCB manufacturing tolerances. We describe two readout patterns, the tetra wedge anode (TWA), an optimized 4 electrode device similar to the wedge and strip anode (WSA) but with a factor 2 improvement in resolution, and an 8 channel high speed 50 ohm device, both manufactured as multilayer PCBs. We present results of the detector imaging performance, image resolution, linearity and stability, and discuss the development of an integrated readout and electronics device based on these designs.

Magnetic resonance imaging of the growth plate: pictorial essay

International Nuclear Information System (INIS)

Cairns, R.

2003-01-01

The approach to musculoskeletal magnetic resonance imaging (MRI) is very different in children than adults because of different disease processes, immature structures and the variable size and age of the patients. Use of routine adult musculoskeletal protocols and techniques may not provide sufficient information in children, and most pediatric examinations should be customized to specifically address the child's age and clinical problem. This pictorial essay will illustrate MRI of the growth plate - often an area of uncertainty or error for radiologists who infrequently perform musculoskeletal MRI on children. The growth plate or physis is a structure unique to the growing skeleton. It is a cartilaginous zone located between the epiphysis and the metaphysis that functions to provide longitudinal bone growth. Disturbance of physeal growth as a result of trauma, infection, tumour, ischemia or radiation can result in leg length discrepancy, angular deformity or altered joint mechanics and cause significant long-term disability. MRI can directly image cartilaginous structures and has thus become the imaging method of choice for evaluation of the growth plate. An understanding of the normal and abnormal appearance of growth cartilage and of MRI protocols optimized for imaging the growth plate, combined with an approach to risk assessment for the development of significant growth deformity, is needed to confidently image the growth plate and help direct the management of these patients. (author)

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

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

International Nuclear Information System (INIS)

Oliveira, Davi F.; Silva, Aline S.S.; Machado, Alessandra S.; Gomes, Celio S.; Nascimento, Joseilson; Lopes, Ricardo T.

2015-01-01

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 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

Ultrahigh resolution radiation imaging system using an optical fiber structure scintillator plate.

Science.gov (United States)

Yamamoto, Seiichi; Kamada, Kei; Yoshikawa, Akira

2018-02-16

High resolution imaging of radiation is required for such radioisotope distribution measurements as alpha particle detection in nuclear facilities or high energy physics experiments. For this purpose, we developed an ultrahigh resolution radiation imaging system using an optical fiber structure scintillator plate. We used a ~1-μm diameter fiber structured GdAlO 3 :Ce (GAP) /α-Al 2 O 3 scintillator plate to reduce the light spread. The fiber structured scintillator plate was optically coupled to a tapered optical fiber plate to magnify the image and combined with a lens-based high sensitivity CCD camera. We observed the images of alpha particles with a spatial resolution of ~25 μm. For the beta particles, the images had various shapes, and the trajectories of the electrons were clearly observed in the images. For the gamma photons, the images also had various shapes, and the trajectories of the secondary electrons were observed in some of the images. These results show that combining an optical fiber structure scintillator plate with a tapered optical fiber plate and a high sensitivity CCD camera achieved ultrahigh resolution and is a promising method to observe the images of the interactions of radiation in a scintillator.

Zone plate imaging of 14-MeV neutrons

International Nuclear Information System (INIS)

Lerche, R.A.; Lane, S.M.; Hawryluk, A.M.; Ceglio, N.M.

1986-01-01

At Livermore we are interested in imaging the thermonuclear burn region of fusion targets irradiated at our Nova laser facility. We expect compressed core diameters to be 10's of microns, and would like images with better than 10-μm resolution. Alpha particle images provided the first direct information about the thermonuclear burn geometry in thin walled exploding pusher targets. In future high density target experiments, only highly penetrating radiations like the 14-MeV neutrons will escape the target core to provide information about the burn region. To make the measurement with a neutron ''pinhole'' camera requires a 10μm pinhole through about 10 cm of material and 10 14 to 10 15 source neutrons. Penumbral imaging offers some improvement over a pinhole. Zone plate coded imaging (ZPCI) techniques are particularly well suited for imaging small objects like the compressed core of a laser fusion target. We have been using ZPCI techniques to image nonpenetrating radiations like x rays and alpha particles for about 10 years. The techniques are well developed. Imaging penetrating radiations like 14-MeV neutrons using ZPCI techniques has several possible advantages. The large solid angle subtended by the Zone plate might substantially reduce the required target neutron yield needed to produce a useful image, and a neutron zone plate system with 10-μm resolution might be easier to fabricate and characterize than a pinhole system. This paper explores the use of ZPCI techniques with penetrating radiation

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...... most phase objects, including magnetic and electrostatic fields in vacuum. The requirement for phase plate imaging, including that by HFPP, is that the object spectrum in the back focal plane of the objective lens must not be broadened via the effect of chromatic aberration. In other words, the imaged...

Observation of parametric X-ray radiation by an imaging plate

International Nuclear Information System (INIS)

Takabayashi, Y.; Shchagin, A.V.

2012-01-01

We have demonstrated experimentally the application of an imaging plate for registering the angular distribution of parametric X-ray radiation. The imaging plate was used as a two-dimensional position-sensitive X-ray detector. High-quality images of the fine structure in the angular distributions of the yield around the reflection of the parametric X-ray radiation produced in a silicon crystal by a 255-MeV electron beam from a linear accelerator have been observed in the Laue geometry. A fairly good agreement between results of measurements and calculations by the kinematic theory of parametric X-ray radiation is shown. Applications of the imaging plates for the observation of the angular distribution of X-rays produced by accelerated particles in a crystal are also discussed.

Comparison of vessel contrast measured with a scanning-beam digital x-ray system and an image intensifier/television system

International Nuclear Information System (INIS)

Speidel, Michael A.; Wilfley, Brian P.; Heanue, Joseph A.; Betts, Timothy D.; Van Lysel, Michael S.

2001-01-01

Vessel contrast was measured in the fluoroscopic images produced by a scanning-beam digital x-ray (SBDX) system and an image intensifier/television (II/TV) based system. The SBDX system electronically scans a series of pencil x-ray beams across the patient, each of which is directed at a distant small-area detector array. The reduction in detected scatter achieved with this geometry was expected to provide an increase in image contrast. Vessel contrast was evaluated from images of a phantom containing iodinated tubes. The vessels were inserted into an acrylic stack to provide a patient-mimicking scattering medium. Vessel diameter ranged from 0.3 to 3.1 mm. Images were acquired at 100 kVp with the SBDX and II/TV systems and averaged to reduce x-ray noise. The II/TV system was operated in the 6-in. image intensifier mode with an anti-scatter grid. The increase in contrast in the SBDX images, expressed as a ratio of the measured SBDX and II/TV contrasts, ranged from 1.63 to 1.79 for individual vessels. This agreed well with a prediction of the contrast improvement ratio for this experiment, based on measurements of the scatter fraction, object-plane line spread functions, and consideration of the source spectrum and detector absorption properties. The predicted contrast improvement ratio for SBDX relative to II/TV images was 1.62 to 1.77

Direct view panel type X-ray image intensifier tube

International Nuclear Information System (INIS)

Yang, S.-P.; Robbins, C.D.; Merrit, E.

1977-01-01

A panel shaped, proximity type, X-ray image intensifier tube for medical X-ray fluoroscopy use is described. It has all linear components and yet a high brightness gain, in excess of 4,000 cd-sec/m 2 -R, the tube being comprised of a rugged metallic tube envelope, an inwardly concave metallic input window, a directly viewable full size output display screen, and a scintillator-photocathode screen having a thickness of at least 200 microns for a high X-ray photon utilization ability as well as X-ray stopping power, the scintillator-photocathode screen being suspended on insulators within the envelope and in between the input window and the output screen. The scintillator-photocathode screen is spaced from the output screen by at least 8mm to allow the application of a high negative potential at the scintillator-photocathode screen with respect to the output screen for high gain with low field emission, since all of the remaining components within the tube envelope are at neutral potential with respect to the output display screen. (Auth.)

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.

Zone-plate coded imaging of thermonuclear burn

International Nuclear Information System (INIS)

Ceglio, N.M.

1978-01-01

The first high-resolution, direct images of the region of thermonuclear burn in laser fusion experiments have been produced using a novel, two-step imaging technique called zone-plate coded imaging. This technique is extremely versatile and well suited for the microscopy of laser fusion targets. It has a tomographic capability, which provides three-dimensional images of the source distribution. It is equally useful for imaging x-ray and particle emissions. Since this technique is much more sensitive than competing imaging techniques, it permits us to investigate low-intensity sources

Operating radiographic image intensifier tube

International Nuclear Information System (INIS)

Marche, E.; Girard, A.; Barjot, D.; Deon, J.M.; Lacoste, Y.

1996-01-01

The intensifier tube operation method involves a voltage supply (U) which is placed across two transistors (Q 1, Q 2) in series. The voltage driver to the photocathode (PC) is the centre point between the two transistors. A switching command is applied to a logic circuit (CL). The logic circuit drives two light emitting diodes (DEL1, DEL2) when a threshold light level is exceeded, each LED triggers an optical switch (TR1, TR2). The switches change the state of the transistors. Switching the upper transistor on and the lower transistor off applies a voltage to the photocathode. Switching off the upper transistor and on the lower transistor blocks the high voltage and sets the photocathode to zero. The advantage of this device is that it involves circuit regulator which is less complex, it has cheaper and more easily implemented transient protection and has reduced sizes. (authors). 10 figs

Microchannel plates as detectors and amplifiers of x-ray images

International Nuclear Information System (INIS)

Wiedwald, J.D.

1992-08-01

Two decades of development driven largely by military night vision applications has led to the availability of a wide selection of microchannel plates for use by the scientific community. Microchannel plates (MCPs) are electron multipliers which retain a high degree of spatial resolution making it possible to amplify electron images by factors of 1,000 or more. Plates having 40 mm diameter and intrinsic spatial resolution of 8 μm are readily available. By coating the front surface of a microchannel plate with an x-ray sensitive photocathode material, x-ray images can be detected and amplified. While the detective quantum efficiency is relatively low, the low noise of the MCP (including the ability to construct images by single photon detection) and its high dynamic range make it suitable for some x-ray microscopy applications. The principles of MCP operation and typical performance are discussed. Examples of related applications and commercial capabilities are also presented

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.

Fresnel zone plate imaging of a 252Cf spontaneous fission source

International Nuclear Information System (INIS)

Stalker, K.T.; Hessel, K.R.

1976-11-01

The feasibility of coded aperture imaging for nuclear fuel motion monitoring is shown using Cf 252 spontaneous fission source. The theory of coded aperture imaging for Fresnel zone plate apertures is presented and design considerations for zone plate construction are discussed. Actual images are obtained which demonstrate a transverse resolution of 1.7 mm and a tomographic resolution of 1.5 millimeters. The capability of obtaining images through 12.7 mm of stainless steel is also shown

Real-Time Detection of Sporadic Meteors in the Intensified TV Imaging Systems.

Science.gov (United States)

Vítek, Stanislav; Nasyrova, Maria

2017-12-29

The automatic observation of the night sky through wide-angle video systems with the aim of detecting meteor and fireballs is currently among routine astronomical observations. The observation is usually done in multi-station or network mode, so it is possible to estimate the direction and the speed of the body flight. The high velocity of the meteorite flying through the atmosphere determines the important features of the camera systems, namely the high frame rate. Thanks to high frame rates, such imaging systems produce a large amount of data, of which only a small fragment has scientific potential. This paper focuses on methods for the real-time detection of fast moving objects in the video sequences recorded by intensified TV systems with frame rates of about 60 frames per second. The goal of our effort is to remove all unnecessary data during the daytime and make free hard-drive capacity for the next observation. The processing of data from the MAIA (Meteor Automatic Imager and Analyzer) system is demonstrated in the paper.

An imaging method of wavefront coding system based on phase plate rotation

Science.gov (United States)

Yi, Rigui; Chen, Xi; Dong, Liquan; Liu, Ming; Zhao, Yuejin; Liu, Xiaohua

2018-01-01

Wave-front coding has a great prospect in extending the depth of the optical imaging system and reducing optical aberrations, but the image quality and noise performance are inevitably reduced. According to the theoretical analysis of the wave-front coding system and the phase function expression of the cubic phase plate, this paper analyzed and utilized the feature that the phase function expression would be invariant in the new coordinate system when the phase plate rotates at different angles around the z-axis, and we proposed a method based on the rotation of the phase plate and image fusion. First, let the phase plate rotated at a certain angle around the z-axis, the shape and distribution of the PSF obtained on the image surface remain unchanged, the rotation angle and direction are consistent with the rotation angle of the phase plate. Then, the middle blurred image is filtered by the point spread function of the rotation adjustment. Finally, the reconstruction images were fused by the method of the Laplacian pyramid image fusion and the Fourier transform spectrum fusion method, and the results were evaluated subjectively and objectively. In this paper, we used Matlab to simulate the images. By using the Laplacian pyramid image fusion method, the signal-to-noise ratio of the image is increased by 19% 27%, the clarity is increased by 11% 15% , and the average gradient is increased by 4% 9% . By using the Fourier transform spectrum fusion method, the signal-to-noise ratio of the image is increased by 14% 23%, the clarity is increased by 6% 11% , and the average gradient is improved by 2% 6%. The experimental results show that the image processing by the above method can improve the quality of the restored image, improving the image clarity, and can effectively preserve the image information.

Influence of veiling glare in the image intensifier on cinefluorographic sensitometry

International Nuclear Information System (INIS)

Matsuda, Eiji; Sanada, Taizo; Hitomi, Go; Ishii, Koushi; Yoshida, Akira

1998-01-01

We have experienced variations in the shape of the cinesensitometric curve when the exposure field is greatly altered. The veiling glare that arises from the scattering of x-ray photons, electrons, and light in the x-ray image intensifier (X-I.I.) depends on the size of the exposure field. Also, the effect of adjacent chemicals that occurs during the development process depends on the size of the exposed area on film. The veiling glare in the X-I.I. and the adjacent chemical effect on cine film processing may be responsible for these phenomena. This study investigated the influences of veiling glare on the shape of the cinesensitometric curve. Results showed that the veiling glare of the X-I.I. acts to increase the sensitivity of the cinesensitometric curve on the X-I.I. when the exposed area on the X-I.I. is larger. (author)

Influence of veiling glare in the image intensifier on cinefluorographic sensitometry

Energy Technology Data Exchange (ETDEWEB)

Matsuda, Eiji; Sanada, Taizo; Hitomi, Go; Ishii, Koushi [Kawasaki Medical School, Kurashiki, Okayama (Japan). Hospital; Yoshida, Akira

1998-08-01

We have experienced variations in the shape of the cinesensitometric curve when the exposure field is greatly altered. The veiling glare that arises from the scattering of x-ray photons, electrons, and light in the x-ray image intensifier (X-I.I.) depends on the size of the exposure field. Also, the effect of adjacent chemicals that occurs during the development process depends on the size of the exposed area on film. The veiling glare in the X-I.I. and the adjacent chemical effect on cine film processing may be responsible for these phenomena. This study investigated the influences of veiling glare on the shape of the cinesensitometric curve. Results showed that the veiling glare of the X-I.I. acts to increase the sensitivity of the cinesensitometric curve on the X-I.I. when the exposed area on the X-I.I. is larger. (author)

Measurement of environmental radioactivity with photo-diode and Imaging Plate

International Nuclear Information System (INIS)

Mori, C.; Sumi, T.; Gotoh, S.; Saze, T.; Nishizawa, K.

2000-01-01

Measurement of environmental radioactivity with photo-diode (PD) and Imaging Plate (IP) was tired. Commercially available Si PIN type PD's generally have depletion layer thickness more than a few hundred micrometer, which is enough for alpha particle measurement. PD's have various features: being usable in normal temperature, high energy resolution and low cost. Radon daughter nuclides positively charged in atmosphere were collected on the PD surface with negative electric potential and measured the pulse height spectra of alpha-particles from the daughter nuclides of Radon in thorium oxide, uranium ore, granite, and concrete. Counting of alpha-particles with IP was tired. Lead plates usually contain Pb-210 (RaD) and emit alpha-particles from Po-210. The alpha-particles from the plate were counted with PD and the plate was exposed to IP. By adjusting the gradation level on the reading out of the latent image, it was possible to count alpha-particle incident image one by one, and the number per 1 cm 2 was compared with the number of count with PD. (author)

Real-time imaging of radioisotope labeled compounds in a living plant

International Nuclear Information System (INIS)

Kanno, S.; Ohya, T.; Hayashi, Y.; Tanoi, K.; Nakanishi, T.M.

2007-01-01

We developed a quantitative, real-time imaging system of labeled compounds in a living plant. The system was composed of CsI scintillator to convert β-rays to visible light and an image intensifier unit (composed of GaAsP semiconductor and MCP; micro channel plate) to detect extremely weak light. When the sensitivity and resolution of the image of our system was compared with that of an imaging plate (IP), the sensitivity of our system (with 20 minutes) was higher than that of an IP, with similar quality to that of an IP. Using this system, the translocation of 32 P in a soybean plant tissue was shown in successive images. (author)

Post-process intensification of photographic silver images, using radioactive compounds

International Nuclear Information System (INIS)

1979-01-01

A method of post-process intensification of silver images on a developed and fixed photographic film or plate is described, comprising the steps of (a) converting silver of the developed film or plate to a radioactive compound by contracting the film or plate with an aqueous alkaline solution of an organo-S 35 compound which reacts selectively with silver in a photographic film or plate; (b) placing the film or plate treated in step (a) in direct contact with a receiver film which is sensitive to beta radiation whereby the receiver film is exposed by radiation from the radioactive compound; and (c) developing and fixing the resulting intensified receiver film. (author)

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

International Nuclear Information System (INIS)

Ferreira de Oliveira, Davi; Silva, Aline S.S.; Machado, Alessandra S.; Gomes, Celio S.; Nascimento, Joseilson R.; Lopes, Ricardo T.

2016-01-01

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 evaluated procedures for employing Computed Radiography (CR) to welding inspections in laboratory conditions using the Simple Wall Simple Image Technique (SWSI). CR tests were performed in steel welded joins of thickness 5.33, 12.70 and 25.40 mm. It was used an X-Ray equipment as radiation source. The image quality parameters Basic Spatial Resolution (BSR), Normalized Signal-to-Noise Ratio (SNRN), 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 IPs are essential for determining the quality of the digital radiography images acquired with them. Regarding the grain size and the thickness of the IPs' sensitive layers, we could determine that the dimensions of such parameters were smaller on the plates presenting higher BSR, SNRN and contrast. However, the image plates which produced images with the highest resolution have also proven to be the least sensitive ones. All these parameters have a direct influence in the detectability of the

Paediatric interventional cardiology: flat detector versus image intensifier using a test object

Science.gov (United States)

Vano, E.; Ubeda, C.; Martinez, L. C.; Leyton, F.; Miranda, P.

2010-12-01

Entrance surface air kerma (ESAK) values and image quality parameters were measured and compared for two biplane angiography x-ray systems dedicated to paediatric interventional cardiology, one equipped with image intensifiers (II) and the other one with dynamic flat detectors (FDs). Polymethyl methacrylate phantoms of different thicknesses, ranging from 8 to 16 cm, and a Leeds TOR 18-FG test object were used. The parameters of the image quality evaluated were noise, signal-difference-to-noise ratio (SdNR), high contrast spatial resolution (HCSR) and three figures of merit combining entrance doses and signal-to-noise ratios or HCSR. The comparisons showed a better behaviour of the II-based system in the low contrast region over the whole interval of thicknesses. The FD-based system showed a better performance in HCSR. The FD system evaluated would need around two times more dose than the II system evaluated to reach a given value of SdNR; moreover, a better spatial resolution was measured (and perceived in conventional monitors) for the system equipped with flat detectors. According to the results of this paper, the use of dynamic FD systems does not lead to an automatic reduction in ESAK or to an automatic improvement in image quality by comparison with II systems. Any improvement also depends on the setting of the x-ray systems and it should still be possible to refine these settings for some of the dynamic FDs used in paediatric cardiology.

Paediatric interventional cardiology: flat detector versus image intensifier using a test object

Energy Technology Data Exchange (ETDEWEB)

Vano, E [Radiology Department, Medicine School, Complutense University and San Carlos University Hospital, 28040 Madrid (Spain); Ubeda, C [Clinical Sciences Department, Faculty of the Science of Health and CIHDE, Tarapaca University, 18 de Septiembre 2222, Arica (Chile); Martinez, L C [Medical Physics and Radiation Protection Service, 12 de Octubre University Hospital, Madrid (Spain); Leyton, F [Institute of Public Health of Chile, Marathon 1000, Nunoa, Santiago (Chile); Miranda, P, E-mail: eliseov@med.ucm.e [Hemodynamic Department, Cardiovascular Service, Luis Calvo Mackenna Hospital, Avenida Antonio Varaas 360, Providencia, Santiago (Chile)

2010-12-07

Entrance surface air kerma (ESAK) values and image quality parameters were measured and compared for two biplane angiography x-ray systems dedicated to paediatric interventional cardiology, one equipped with image intensifiers (II) and the other one with dynamic flat detectors (FDs). Polymethyl methacrylate phantoms of different thicknesses, ranging from 8 to 16 cm, and a Leeds TOR 18-FG test object were used. The parameters of the image quality evaluated were noise, signal-difference-to-noise ratio (SdNR), high contrast spatial resolution (HCSR) and three figures of merit combining entrance doses and signal-to-noise ratios or HCSR. The comparisons showed a better behaviour of the II-based system in the low contrast region over the whole interval of thicknesses. The FD-based system showed a better performance in HCSR. The FD system evaluated would need around two times more dose than the II system evaluated to reach a given value of SdNR; moreover, a better spatial resolution was measured (and perceived in conventional monitors) for the system equipped with flat detectors. According to the results of this paper, the use of dynamic FD systems does not lead to an automatic reduction in ESAK or to an automatic improvement in image quality by comparison with II systems. Any improvement also depends on the setting of the x-ray systems and it should still be possible to refine these settings for some of the dynamic FDs used in paediatric cardiology.

DAFS measurements using the image-plate Weissenberg method

International Nuclear Information System (INIS)

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

1998-01-01

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 χ(k), Fourier transforms of k 3 χ(k) and back-Fourier filtering have been performed

Automatic measurement of images on astrometric plates

Science.gov (United States)

Ortiz Gil, A.; Lopez Garcia, A.; Martinez Gonzalez, J. M.; Yershov, V.

1994-04-01

We present some results on the process of automatic detection and measurement of objects in overlapped fields of astrometric plates. The main steps of our algorithm are the following: determination of the Scale and Tilt between charge coupled devices (CCD) and microscope coordinate systems and estimation of signal-to-noise ratio in each field;--image identification and improvement of its position and size;--image final centering;--image selection and storage. Several parameters allow the use of variable criteria for image identification, characterization and selection. Problems related with faint images and crowded fields will be approached by special techniques (morphological filters, histogram properties and fitting models).

Detection matrix of an electromagnetic radiation and radiological image intensifier comprising such a matrix

International Nuclear Information System (INIS)

Fraleux, Jean.

1982-01-01

This invention concerns a detection matrix comprising, in an electrode lattice of lines and columns, addressing means constituted of thin film technology MOS transistors and photoconductances which enable the number of unit module crossings to be halved and to bring about an increase in the effective detection area. This detection matrix is employed in radiological image intensifiers where it ensures the conversion of incident X photons into reading electric signals or only the detection of a visible radiation in the case where the incident X photons are converted into lesser energy photons by a scintillator. The scintillator is then formed of a panel brought into contact with the detector mosaic [fr

40° image intensifier tubes in an integrated helmet system

Science.gov (United States)

Schreyer, Herbert; Boehm, Hans-Dieter V.; Svedevall, B.

1993-12-01

EUROCOPTER has been under contract to the French and German ministries of defence for five years to develop the TIGER, a second generation anti-tank helicopter. A piloting thermal imager has been installed on a steerable platform in the helicopter nose in order to achieve the possibility of flying round the clock. In addition to this sensor, which is sensitive at a wavelength of 10 micrometers , the German side has proposed using an Integrated Helmet System in the PAH 2. This helmet, manufactured by GEC-Marconi Avionics, incorporates two cathode ray tubes (CRT) and two image intensifier tubes which allow the pilot to use an additional sensor in the visible and near infrared spectrum. The electronic part will be built by Teldix. EUROCOPTER DEUTSCHLAND has received the first demonstrator of this helmet for testing in the EUROCOPTER Visionics Laboratory. Later, the C-prototype will be integrated into a BK 117 helicopter (AVT Avionik Versuchstrager). This new helmet has a field of view of 40 degree(s), and exit pupil of 15 mm and improved possibilities of adjusting the optical part. Laboratory tests have been carried out to test important parameters like optical resolution under low light level conditions, field of view, eye relief or exit pupil. The CRT channels have been tested for resolution, distortion, vignetting and homogeneity. The requirements and the properties of the helmet, test procedures and the results of these tests are presented in the paper.

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.

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...

Use of a Fluorometric Imaging Plate Reader in high-throughput screening

Science.gov (United States)

Groebe, Duncan R.; Gopalakrishnan, Sujatha; Hahn, Holly; Warrior, Usha; Traphagen, Linda; Burns, David J.

1999-04-01

High-throughput screening (HTS) efforts at Abbott Laboratories have been greatly facilitated by the use of a Fluorometric Imaging Plate Reader. The FLIPR consists of an incubated cabinet with integrated 96-channel pipettor and fluorometer. An argon laser is used to excite fluorophores in a 96-well microtiter plate and the emitted fluorometer. An argon laser is used to excite fluorophores in a 96-well microtiter plate and the emitted fluorescence is imaged by a cooled CCD camera. The image data is downloaded from the camera and processed to average the signal form each well of the microtiter pate for each time point. The data is presented in real time on the computer screen, facilitating interpretation and trouble-shooting. In addition to fluorescence, the camera can also detect luminescence form firefly luciferase.

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.

Simulation of dental intensifying screen for intraoral radiographic using MCNP5 code

International Nuclear Information System (INIS)

Ferreira, Vanessa M.; Oliveira, Renato C.M.; Barros, Graiciany P.; Oliveira, Arno H.; Veloso, M. Auxiliadora F.

2011-01-01

One of basic principles for radiological protection is the optimization of techniques for obtain radiographic images, in way that the dose in the patient is kept as low as reasonably achievable (ALARA). Intensifying screens are used in medical radiology, which reduce considerably the dose rates in the production of radiographic images, maintaining the quality of these, while in dental radiology, there is no a intensifying screen available for intraoral examinations. From this technological requirement, this paper evaluates a computational modeling of an intensifying screen for use in intraoral radiography. For this, it was used the Monte Carlo code MCNP5 that allows the radiography simulation through the transport of electrons and photons in the different materials present in this examination. The goal of an intensifying screen is the conversion of X-ray photons to photons in the visible spectrum, knowing that radiographic films are more sensitive to light photons than to X-ray photons. So the screen should be composed of an efficient material for converting x-rays photons in light photons, therefore was made simulations using different materials, thicknesses and positions possible for placing screen in radiographic film in order to find the way more technically feasible. (author)

Properties of image intensifier-related halation artifact in limited volume cone-beam CT for dental use

International Nuclear Information System (INIS)

Hirukawa, Akiko; Okumura, Shinji; Matsuo, Ayae; Yokoi, Midori; Gotoh, Kenichi; Katsumata, Akitoshi; Naitoh, Munetaka; Ariji, Eiichiro

2006-01-01

Artifacts due to halation from an image intensifier (I.I.)/charge coupled device (CCD) system appear on limited-volume cone-beam computed tomography (CBCT). Regarding anterior tooth imaging, properties of this artifact in the geometrical relationships between field of view (FOV) and objective jaw region were studied. A water-filled plastic cylinder was used as a phantom of the head. A test object was constructed as a bone-equivalent phantom to be imaged. The test object was set in the phantom at positions corresponding to the anterior tooth arch. Position of the test object was shifted to simulate individual variations in the thickness of the labial soft tissue. Limited-volume CBCT images were acquired using a 3DX system in the various offset FOV position. The affection of an artifact was evaluated by the size of the object's image. The position of the test object in the phantom, i.e. the thickness of the labial soft tissue contributes to the intensity of artifact. However, even when the labial soft tissue was thick, affection from artifact was prominent when the FOV was set so that the image of the test object was depicted near the margin of FOV. (author)

[Non-rigid medical image registration based on mutual information and thin-plate spline].

Science.gov (United States)

Cao, Guo-gang; Luo, Li-min

2009-01-01

To get precise and complete details, the contrast in different images is needed in medical diagnosis and computer assisted treatment. The image registration is the basis of contrast, but the regular rigid registration does not satisfy the clinic requirements. A non-rigid medical image registration method based on mutual information and thin-plate spline was present. Firstly, registering two images globally based on mutual information; secondly, dividing reference image and global-registered image into blocks and registering them; then getting the thin-plate spline transformation according to the shift of blocks' center; finally, applying the transformation to the global-registered image. The results show that the method is more precise than the global rigid registration based on mutual information and it reduces the complexity of getting control points and satisfy the clinic requirements better by getting control points of the thin-plate transformation automatically.

Performance of a thermal neutron radiographic system using imaging plates

International Nuclear Information System (INIS)

Silvani, Maria Ines; Almeida, Gevaldo L. de; Furieri, Rosanne; Lopes, Ricardo T.

2009-01-01

A performance evaluation of a neutron radiographic system equipped with a thermal neutron sensitive imaging plate has been undertaken. It includes the assessment of spatial resolution, linearity, dynamic range and the response to exposure time, as well as a comparison of these parameters with the equivalent ones for neutron radiography employing conventional films and a gadolinium foil as converter. The evaluation and comparison between the radiographic systems have been performed at the Instituto de Engenharia Nuclear - CNEN, using the Argonauta Reactor as source of thermal neutrons and a commercially available imaging plate reader. (author)

Study of two novel large-field-of-view image intensifiers versus conventional chest radiography with use of FROC methods and simulated pulmonary nodules

International Nuclear Information System (INIS)

Winter, L.H.L.; Chakraborty, D.P.; Van Waes, P.F.G.M.; Puylaert, C.B.A.J.

1989-01-01

Two novel large-field-of-view image intensifier (LFOV 1.1) tubes have been introduced whose image area makes them suitable for chest imaging. Both modalities present a 100-mm hard-copy image to the radiologist. A pulmonary nodule performance experiment was done to compare the diagnostic accuracy of these tubes with conventional full-size chest images. The data were analyzed with the maximum-likelihood FROCFIT program. The relative ranking in terms of decreasing A1 values was TLX, Siemens 43-cm mode, conventional radiography, and Siemens 57-cm mode

Evaluation of edge enhancement effect of phase contrast imaging using newly-developed photostimulable phosphor plate

International Nuclear Information System (INIS)

Matsuo, Satoru; Morishita, Junji; Katafuchi, Tetsuro; Fujita, Hiroshi

2012-01-01

We investigated whether the use of a newly developed columnar-crystal-type photostimulable-phosphor plate (CP1M200, referred to as system C) helps to provide improved edge-enhanced effect in phase contrast imaging. Physical characteristics of 2 conventional particulate-crystal-type photostimulable-phosphor plates (RP-5PM, referred to as system A and RP-6M, referred to as system B) and system C were measured. Then, an acrylic plate phantom and RMI152 phantom were imaged using 3 types of plates, and the edge-enhancement effects were evaluated based on the profile curve of the acrylic plate phantom. Visual evaluation of the RMI152 phantom images was conducted. The results showed that the modulation transfer function (MTF) of system C was superior to those of the other systems. The WS of system C was superior to those of the other systems in the low frequency band region, and inferior to those of the other systems in the high frequency band region. The presence of an edge-enhanced image was not detectable in the profile curve of the acrylic plate in system A, although that was shown in systems B and C due to their excellent sharpness. In the visual image evaluation of the RMI152 phantom, image quality of system C was superior to those of the other systems. Phase contrast imaging with a digital detector of a columnar-crystal-type photostimulable-phosphor plate is considered to provide improved edge-enhancement over that of conventional plates. (author)

X-ray diagnostic installation with an image intensifier TV chain and a dose rate control device

Energy Technology Data Exchange (ETDEWEB)

Duemmling, K; Schott, O

1977-04-28

The person performing the examination can key up the dose rate briefly via the X-ray tube current, e.g., if the movement of a contrast medium is to be observed on the video screen and only certain phases in this movement, which are of diagnostic significance, are to be viewed more closely. The upward change necessary to reduce quantum noise by a certain factor is made by means of a switch. This at the same time results in a reduction of brightness (over-exposure) of the X-ray image on the video screen by actuating an aperture system between the image intensifier, and the TV camera. To prevent the X-ray tube from being overloaded during key-up of the dose rate, a time limit switch is installed in the control system.

Applications of image plates in neutron radiography and neutron diffraction at BARC, Trombay

International Nuclear Information System (INIS)

Shaikh, A.M.

2013-01-01

Neutron radiography techniques based on Gd, Dy and In metallic foils and X-ray film have been used at this centre since early seventies for various NDT and R and D work in nuclear, defence and aerospace industries. In recent years use of photostimulated luminescence based phosphor imaging plate has been introduced in our work. This has enabled to achieve higher sensitivities and dynamic ranges of recording radiographs with acceptable spatial resolution. It also provides digital image information which is more convenient for quantitative evaluations. Neutron image plates have been used in variety of radiography techniques such as conventional neutron radiography (NR), neutron induced beta radiography (NIBR), hydrogen sensitive epithermal neutron radiography (HYSEN) and for neutron powder diffractometry using Apsara, CIRUS and Dhruva reactors as neutron sources. Recently the image plates have also been used for characterization of thermalized neutron beam from a plasma focus neutron source and recording neutron radiographs. Prior to the utilization image plates have been characterised for their performance. Details of the measurements and applications will be presented. (author)

Imaging plate, a new type of x-ray area detector

International Nuclear Information System (INIS)

Kamiya, Nobuo; Amemiya, Yoshiyuki; Miyahara, Junji.

1986-01-01

In respective fields of X-ray crystallography, for the purpose of the efficient collection of reciprocal space information, two-dimensional X-ray detectors such as multiwire proportional chambers and X-ray television sets have been used together with conventional X-ray films. X-ray films are characterized by uniform sensitivity and high positional resolution over a wide area, but the sensitivity is low, and the range of action and the linearity of the sensitivity is problematic. They require the development process, accordingly lack promptitude. The MWPCs and X-ray television sets are superior in the sensitivity, its linearity, the range of action and promptitude, but interior in the uniformity and resolution to the films. Imaging plate is a new X-ray area detector developed by Fuji Photo Film Co., Ltd., for digital X-ray medical image diagnosis. This detector is superior in all the above mentioned performances, and it seems very useful also for X-ray crystallography. In this paper, the system composed of an imaging plate and its reader is described, and the basic performance as an X-ray area detector and the results of having recorded the diffraction images of protein crystals as the example of applying it to X-ray crystallography are reported. The imaging plate is that the crystalline fluorescent powder of BaFBr doped with Eu 2+ ions is applied on plastic films. (Kako, I.)

Data processing correction of the irising effect of a fast-gating intensified charge-coupled device on laser-pulse-excited luminescence spectra.

Science.gov (United States)

Ondic, L; Dohnalová, K; Pelant, I; Zídek, K; de Boer, W D A M

2010-06-01

Intensified charge-coupled devices (ICCDs) comprise the advantages of both fast gating detectors and spectrally broad CCDs into one device that enables temporally and spectrally resolved measurements with a few nanosecond resolution. Gating of the measured signal occurs in the image intensifier tube, where a high voltage is applied between the detector photocathode and a microchannel plate electron multiplier. An issue arises in time-resolved luminescence spectroscopy when signal onset characterization is required. In this case, the transient gate closing process that causes the detected signal always arises in the middle of the ICCD chip regardless of the spectral detection window--the so-called irising effect. We demonstrate that in case when the detection gate width is comparable to the opening/closing time and the gate is pretriggered with respect to the signal onset, the irising effect causes the obtained data to be strongly distorted. At the same time, we propose a software procedure that leads to the spectral correction of the irising effect and demonstrate its validity on the distorted data.

Optical phase plates as a creative medium for special effects in images

Science.gov (United States)

Shaoulov, Vesselin I.; Meyer, Catherine; Argotti, Yann; Rolland, Jannick P.

2001-12-01

A new paradigm and methods for special effects in images were recently proposed by artist and movie producer Steven Hylen. Based on these methods, images resembling painting may be formed using optical phase plates. The role of the mathematical and optical properties of the phase plates is studied in the development of these new art forms. Results of custom software as well as ASAP simulations are presented.

[Medical image elastic registration smoothed by unconstrained optimized thin-plate spline].

Science.gov (United States)

Zhang, Yu; Li, Shuxiang; Chen, Wufan; Liu, Zhexing

2003-12-01

Elastic registration of medical image is an important subject in medical image processing. Previous work has concentrated on selecting the corresponding landmarks manually and then using thin-plate spline interpolating to gain the elastic transformation. However, the landmarks extraction is always prone to error, which will influence the registration results. Localizing the landmarks manually is also difficult and time-consuming. We the optimization theory to improve the thin-plate spline interpolation, and based on it, used an automatic method to extract the landmarks. Combining these two steps, we have proposed an automatic, exact and robust registration method and have gained satisfactory registration results.

Innovative microchannel plate with reformulation of composition and modification of microstructure

Science.gov (United States)

Pan, Jingsheng; Lv, Jingwen; Kesaev, S. A.; Liu, Shulin; Liu, Zhanying; Li, Junguo; Chong, Xiaoqin; Shu, Detan

2009-07-01

The signal-to-noise ratio (SNR) and mean time to failure (MTTF) are two important attributes to describe the performance and operation life of an image intensifier. The presents of the ion barrier film (IBF) in Gen. III image intensifier, which used to suppress MCP's ion feedback, while dramatically improve the MTTF but significantly reduce the SNR, so more completely diminishing the ion poisoning source within the channels of MCP are crucial for improved Gen. III; image intensifier to thinned thickness IBF and achieving this two conflicting attributes promotion simultaneously. This research was originally initiated to develop a MCP with glass composition redesigned specially for GaAs photocathode image intensifier, proved which can be imposed an exceedingly intensive electron bombard degassing but without suffering a fatal gain degrade, and had achieved significantly improved SNR of Gen. III image intensifier but with a short distance to meet the lifetime success, so that our research work step forward to intent upon the restriction of ion poisoning source formation within the MCP substrate, we reformulated the MCP glass composition, and modified the microstructure of this MCP glass substrate though a glass-crystal phase transition during the MCP fabricate heating process, we present an innovative MCP based on a glass-ceramic substrate, with reformulated composition and close-linked network microstructure mix with many of nanometer size crystal grains, provide this MCP with sustainable high gain, lower ion feedback and less outgasing performance, this glass-ceramic MCPs are assembled to Gen. III image intensifiers which results showing promoting both the MTTF and SNR of Gen. III image intensifier.

Neutron radiography of thick hydrogenous materials with use of an imaging plate neutron detector

International Nuclear Information System (INIS)

Kato, K.; Matsumoto, G.; Karasawa, Y.; Niimura, N.; Matsubayashi, M.; Tsuruno, A.

1996-01-01

The value of the neutron mass attenuation coefficient of hydrogen being very high, it is extremely difficult to image normal size, living animals with neutron radiography. However, the authors suggest the possibility of applying neutron radiography for biomedical specimens. The organs in the breast, bones and cartilages in the extremities, and the tail of mice and rats were clearly imaged by neutron radiography with Gd foils as neutron converters and X-ray films. However, no contours of the organs in the mouse abdomen were visible with neutron radiography with an exposure time of 200 s. By adding Gd or Li compounds as neutron converters to imaging X-ray plates, imaging plates have been developed for neutron detectors. A trial using these imaging plates for neutron radiography of water-filled containers and the abdomen of mice was completed. The roundness of a 100 ml-beaker was imaged with a neutron exposure of 180 s. Obscure contours of the liver and kidneys of the mouse were imaged with a neutron exposure of 100 s. (orig.)

Quantitative imaging of turbulent and reacting flows

Energy Technology Data Exchange (ETDEWEB)

Paul, P.H. [Sandia National Laboratories, Livermore, CA (United States)

1993-12-01

Quantitative digital imaging, using planar laser light scattering techniques is being developed for the analysis of turbulent and reacting flows. Quantitative image data, implying both a direct relation to flowfield variables as well as sufficient signal and spatial dynamic range, can be readily processed to yield two-dimensional distributions of flowfield scalars and in turn two-dimensional images of gradients and turbulence scales. Much of the development of imaging techniques to date has concentrated on understanding the requisite molecular spectroscopy and collision dynamics to be able to determine how flowfield variable information is encoded into the measured signal. From this standpoint the image is seen as a collection of single point measurements. The present effort aims at realizing necessary improvements in signal and spatial dynamic range, signal-to-noise ratio and spatial resolution in the imaging system as well as developing excitation/detection strategies which provide for a quantitative measure of particular flowfield scalars. The standard camera used for the study is an intensified CCD array operated in a conventional video format. The design of the system was based on detailed modeling of signal and image transfer properties of fast UV imaging lenses, image intensifiers and CCD detector arrays. While this system is suitable for direct scalar imaging, derived quantities (e.g. temperature or velocity images) require an exceptionally wide dynamic range imaging detector. To apply these diagnostics to reacting flows also requires a very fast shuttered camera. The authors have developed and successfully tested a new type of gated low-light level detector. This system relies on fast switching of proximity focused image-diode which is direct fiber-optic coupled to a cooled CCD array. Tests on this new detector show significant improvements in detection limit, dynamic range and spatial resolution as compared to microchannel plate intensified arrays.

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)

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.

Transfer, imaging, and analysis plate for facile handling of 384 hanging drop 3D tissue spheroids.

Science.gov (United States)

Cavnar, Stephen P; Salomonsson, Emma; Luker, Kathryn E; Luker, Gary D; Takayama, Shuichi

2014-04-01

Three-dimensional culture systems bridge the experimental gap between in vivo and in vitro physiology. However, nonstandardized formation and limited downstream adaptability of 3D cultures have hindered mainstream adoption of these systems for biological applications, especially for low- and moderate-throughput assays commonly used in biomedical research. Here we build on our recent development of a 384-well hanging drop plate for spheroid culture to design a complementary spheroid transfer and imaging (TRIM) plate. The low-aspect ratio wells of the TRIM plate facilitated high-fidelity, user-independent, contact-based collection of hanging drop spheroids. Using the TRIM plate, we demonstrated several downstream analyses, including bulk tissue collection for flow cytometry, high-resolution low working-distance immersion imaging, and timely reagent delivery for enzymatic studies. Low working-distance multiphoton imaging revealed a cell type-dependent, macroscopic spheroid structure. Unlike ovarian cancer spheroids, which formed loose, disk-shaped spheroids, human mammary fibroblasts formed tight, spherical, and nutrient-limited spheroids. Beyond the applications we describe here, we expect the hanging drop spheroid plate and complementary TRIM plate to facilitate analyses of spheroids across the spectrum of throughput, particularly for bulk collection of spheroids and high-content imaging.

Diels–Alder reactions of myrcene using intensified continuous-flow reactors

Directory of Open Access Journals (Sweden)

Christian H. Hornung

2017-01-01

Full Text Available This work describes the Diels–Alder reaction of the naturally occurring substituted butadiene, myrcene, with a range of different naturally occurring and synthetic dienophiles. The synthesis of the Diels–Alder adduct from myrcene and acrylic acid, containing surfactant properties, was scaled-up in a plate-type continuous-flow reactor with a volume of 105 mL to a throughput of 2.79 kg of the final product per day. This continuous-flow approach provides a facile alternative scale-up route to conventional batch processing, and it helps to intensify the synthesis protocol by applying higher reaction temperatures and shorter reaction times.

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...

Development of a single-photon-counting camera with use of a triple-stacked micro-channel plate.

Science.gov (United States)

Yasuda, Naruomi; Suzuki, Hitoshi; Katafuchi, Tetsuro

2016-01-01

At the quantum-mechanical level, all substances (not merely electromagnetic waves such as light and X-rays) exhibit wave–particle duality. Whereas students of radiation science can easily understand the wave nature of electromagnetic waves, the particle (photon) nature may elude them. Therefore, to assist students in understanding the wave–particle duality of electromagnetic waves, we have developed a photon-counting camera that captures single photons in two-dimensional images. As an image intensifier, this camera has a triple-stacked micro-channel plate (MCP) with an amplification factor of 10(6). The ultra-low light of a single photon entering the camera is first converted to an electron through the photoelectric effect on the photocathode. The electron is intensified by the triple-stacked MCP and then converted to a visible light distribution, which is measured by a high-sensitivity complementary metal oxide semiconductor image sensor. Because it detects individual photons, the photon-counting camera is expected to provide students with a complete understanding of the particle nature of electromagnetic waves. Moreover, it measures ultra-weak light that cannot be detected by ordinary low-sensitivity cameras. Therefore, it is suitable for experimental research on scintillator luminescence, biophoton detection, and similar topics.

Preliminary examination of the applicability of imaging plates to fast neutron radiography

International Nuclear Information System (INIS)

Matsubayashi, Masahito; Hibiki, Takashi; Mishima, Kaichiro; Yoshii, Koji; Okamoto, Koji

2001-01-01

Fast neutron radiography is an attractive non-destructive inspection technique because of the excellent penetration characteristics of fast neutrons in matter. However, the difficulty of detecting fast neutrons reduces this attractive feature. As an experiment to overcome the difficulty, imaging plates were applied to fast neutron radiography. A simple combination of two sheets of imaging plates and a sheet of polyethylene as a proton emitter was examined with the (fast neutron, thermal neutron and gamma ray) FTG discriminator proposed by Yoneda et al. . The experimental results showed that the method could be applicable to fast neutron radiography with effective discrimination of γ-rays

Effect of background radiation shielding on natural radioactivity distribution measurement with imaging plate

International Nuclear Information System (INIS)

Mori, C.; Suzuki, T.; Koido, S.; Uritani, A.; Miyahara, H.; Yanagida, K.; Miyahara, J.; Takahashi, K.

1996-01-01

Distribution images of natural radioactivity contained in various natural materials such as vegetable, animal meat and pottery work can be obtained with an imaging plate which has high sensitivity for nuclear radiations. For such very low levels of radioactivity, natural background radiations must be reduced using a shielding box. The lining, on the inside of the box, with low atomic number material such as acrylic resin is very effective in reducing electrons, β-rays and low energy X- and γ-rays emitted from the inner surface of the shielding material. Some images of natural radioactivity distribution were obtained and the radioactivity, mainly 40 K, contained in natural materials was measured by using an HPGe detector and also the imaging plate itself. (orig.)

Applications of 'edge-on' illuminated porous plate detectors for diagnostic X-ray imaging

CERN Document Server

Shikhaliev, P M

2002-01-01

Scanning X-ray imaging systems for non-invasive diagnostics have several advantages over conventional imaging systems using area detectors. They significantly reduce the detected scatter radiation, cover large areas and potentially provide high spatial resolution. Applications of one-dimensional gaseous detectors and 'edge-on' illuminated silicon strip detectors for scanning imaging systems are currently under intensive investigation. The purpose of this work is to investigate 'edge-on' illuminated Porous Plate (PP) detectors for applications in diagnostic X-ray imaging. MicroChannel Plate (MCP), which is a common type of PP, has previously been investigated as a detector in surface-on illumination mode for medical X-ray imaging. However, its detection efficiency was too low for medical imaging applications. In the present study, the PP are used in the 'edge-on' illumination mode. Furthermore, the structural parameters of different PP types are optimized to improve the detection efficiency in the diagnostic X...

Image quality and radiation exposure in digital storage plate mammography with magnification technique

International Nuclear Information System (INIS)

Fiedler, E.; Aichinger, U.; Boehner, C.; Schulz-Wendtland, R.; Bautz, W.; Saebel, M.

1999-01-01

Purpose: Comparison of image quality between digital phosphor storage plate mammography in magnification technique and a conventional film screen system regarding the special aspect of radiation exposure. Materials and Methods: Radiograms of a RMI-mammography phantom were acquired using a conventional film screen system and two digital storage plate systems. Additionally, the radiograms of one digital system were postprocessed emphasizing contrast and included in the comparison. Results: The detectability of details in storage plate mammographies with magnification technique is almost equal to that of film screen mammographies. Thereby, lower radiation exposures were necessary using the digital systems. Conclusions: Based on these results, storage plate mammography in magnification technique is used in clinical routine at our institution. The correct parameters in image postprocessing are of elementary importance for detail detectability. Future studies must show, whether the lower radiation exposure in digital radiograms of the breast, revealing much higher background noise, will allow the same detail detectability as film screen mammographies. (orig.) [de

Value of intensified nursing

OpenAIRE

Raymann, Cornelia; Konta, Brigitte; Prusa, Nina; Frank, Wilhelm

2006-01-01

The concept "intensified nursing" is mentioned in differentiation to concepts of "nursing care" or "nursing" which intensifies resources or patient contact. Especially psychic and social needs of patients are very appreciated in nursing. A similar type of nursing is known under the concept "advanced nursing practice" (ANP) which means, that a specialised, academically trained nurse offers an extended nursing care in which a focus on the published knowledge of evidence based research is made. ...

Lexicon and Description of Sui Adjective Intensifiers

Directory of Open Access Journals (Sweden)

James N. Stanford

2007-01-01

Full Text Available Sui, an indigenous minority language of southwest China, has an elaborate system of adjective intensification. Adjectives are intensified with word-specific, bound morphemes that usually either rhyme with the base or alliterate with the base. Stanford (2007 notes morpho-phonological patterns that suggest reduplication, rhyme, alliteration, The Emergence of the Unmarked (McCarthy & Prince 1994, Yip 2001, identity avoidance, and “Copy But Don’t Repeat” (Kennard 2004. However, the adjective intensifiers defy a simple, fully predictable explanation in such terms; the intensifier lexicon may be best described as “patterned variety,” a case of lexicalized poetry or a poeticized lexicon. Word formation is guided by general patterns, but each specific intensifier may vary within those overall guidelines. Many adjectives have multiple intensifiers that bear subtle semantic and pragmatic distinctions. The current paper serves as a complement to Stanford (2007 by providing a detailed lexicon of the Sui adjective intensifiers for future reference and further analysis. This lexicon is based on the author’s fieldwork and represents the first detailed account of Sui adjective intensifiers for the wider linguistic community.

Study on evaluation method for image quality of radiograph by step plate, (2)

International Nuclear Information System (INIS)

Terada, Yukihiro; Hirayama, Kazuo; Katoh, Mitsuaki.

1992-01-01

Recently, penetrameter sensitivity is used not only for the evaluation of radiographic image quality but also as a control method for examination conditions. However, it is necessary to take the parametric data for radiation quality in order to use it for the second purpose. The quantitative factor of radiation quality is determined by the absorption coefficient and the ratio of scattered radiation to transmitted radiation reaching the X-ray film. When the X-ray equipment changes in conducting the radiographic examination, these data must be measured in each case. This is a demerit in controlling examination conditions based on parametric data. As shown theoretically in the first report, the image quality value of a step plate which is defined by the density difference divided by film contrast and step plate thickness is useful to obtain the value of the radiation quality factor. This report deal with experimental investigation to measure it with the step plate. The result is showing that the value of the radiation quality factor calculated by the parametric data corresponded well with the image quality value measured by the step plate. Therefore, the convenient method to measure the value of the radiation quality factor has been established in order to control examination conditions in radiographic examination. (author)

Dust visualisation in TJ-II with intensified visible fast cameras

International Nuclear Information System (INIS)

Cal, E. de la; Pablos, J. L. de; Carralero, D.; Hidalgo, C.

2010-01-01

A visible fast camera equipped with an image Intensifier and atomic line filters is used in TJ-II for spectroscopic dust observation. First results show characteristic features depending on filter and clearly differing from those without the filters as is usually done in existing experiments. Preliminary discussions of the observed results are presented. (Author) 5 refs.

Dust visualisation in TJ-II with intensified visible Fast Cameras

Energy Technology Data Exchange (ETDEWEB)

Cal, E. de la; Pablos, J. L. de; Carralero, D.; Hidalgo, C.

2010-10-21

A visible fast camera equipped with an image Intensifier and atomic line filters is used in TJ-II for spectroscopic dust observation. First results show characteristic features depending on filter and clearly differing from those without the filters as is usually done in existing experiments. Preliminary discussions of the observed results are presented. (Author) 5 refs.

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.

A tilted fiber-optic plate coupled CCD detector for high resolution neutron imaging

Energy Technology Data Exchange (ETDEWEB)

Kim, Jongyul; Cho, Gyuseong [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Kim, Jongyul; Hwy, Limchang; Kim, Taejoo; Lee, Kyehong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, Seungwook [Pusan National Univ., Pusan (Korea, Republic of)

2013-05-15

One of these efforts is that a tilted scintillator geometry and lens coupled CCD detector for neutron imaging system were used to improve spatial resolution in one dimension. The increased spatial resolution in one dimension was applied to fuel cell study. However, a lens coupled CCD detector has lower sensitivity than a fiber-optic plate coupled CCD detector due to light loss. In this research, a tilted detector using fiber-optic plate coupled CCD detector was developed to improve resolution and sensitivity. In addition, a tilted detector can prevent an image sensor from direct radiation damage. Neutron imaging has been used for fuel cell study, lithium ion battery study, and many scientific applications. High quality neutron imaging is demanded for more detailed studies of applications, and spatial resolution should be considered to get high quality neutron imaging. Therefore, there were many efforts to improve spatial resolution.

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.)

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

International Nuclear Information System (INIS)

Dudink, Jeroen; Govaert, Paul; Zwol, Arjen L. van; Conneman, Nikk; Goudoever, Johannes B. van; Buijs, Jan; Lequin, Maarten

2010-01-01

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.)

Analysis of distribution of PSL intensity recorded in imaging plate

International Nuclear Information System (INIS)

Oda, Keiji; Tsukahara, Kazutaka; Tada, Hidenori; Yamauchi, Tomoya

2006-01-01

Supplementary experiments and theoretical consideration have been performed about a new method for particle identification with an imaging plate, which was proposed in the previous paper. The imaging plate was exposed to 137 Cs γ-rays, 2 MeV- protons accelerated by a tandem Van de Graaff, X-rays emitted from a tube operated under the condition of 20-70 kV, as well as α- and β-rays. The frequency distribution in PSL intensity in a pixel of 100μm x 100μm was measured and the standard deviation was obtained by fitting to a Gaussian. It was confirmed that the relative standard deviation decreased with the average PSL intensity for every radiation species and that the curves were roughly divided into four groups of α-rays, protons, β-rays and photons. In the second step, these data were analyzed by plotting the square of the relative standard deviation against the average PSL intensity in full-log scale, where the relation should be expressed by a straight line with an slope of -1 provided that the deviation could be dominated only by statistical fluctuation. The data for α- and β-rays deviated from a straight line and approached to each saturated value as the average PSL intensity increased. This saturation was considered to be caused by inhomogeneity in the source intensity. It was also out that the value of interception on full-log plot would have important information about PSL reading efficiency, one of characteristic parameters of imaging plate. (author)

Reconstruction of the sellar floor using a silicone plate in transsphenoidal surgery and its postoperative appearance on magnetic resonance images

International Nuclear Information System (INIS)

Kabuto, Masanori; Kubota, Toshihiko; Kobayashi, Hidenori; Sato, Kazufumi; Ishii, Hisao; Nakagawa, Takao; Arai, Ryowa; Kitai, Ryuhei; Tuchida, Akira

1993-01-01

The reconstruction of the sellar floor using a silicone plate in transsphenoidal surgery and its postoperative appearance on magnetic resonance (MR) images are described. Thirty-eight patients with pituitary adenoma and four with Rathke's cleft cyst underwent this operation and postoperative MR imaging over a 4-year period. A fitting silicone plate for closing of the sellar floor window could be easily made from a large silicone block at the operation. The postoperative position of the silicone plate could be clearly detected by MR imaging as a very low intensity plate on both T1- and T2-weighted sagittal images. (author)

Lorestan Bronze Plate Design Identification by Nondestructive Radiography Method and Image Processing by Means of Histogram Matching

International Nuclear Information System (INIS)

Yahaghi, E.; Movafeghi, A.; Ahmadi, S.; Rokrok, B.; Mohammadzadeh, N.; Rastkhah, N.

2013-01-01

Radiography is known as one of the oldest and most widely used nondestructive testing techniques, where it introduces the most appreciated technique by producing images which are acting as unique fingerprint records of samples of interest. Among the interesting applications of radiography are archaeological and art applications. In this research, radiography was implemented for identification of a damaged art-historical material. The sample was a brass plate belonging to Iran cultural heritage. The estimated age of the plate was about 3500 years. The plate was discovered in Lorestan province, where it is generally called L orestan bronze . The plate was damaged seriously due to serious corrosion environmental attacks, and recognition of the sample was considered as the major problem. The simple radiography method was quite helpful for the plate determination but the method suffered from some major drawbacks due to contrast and thickness measurements. The thickness measurement and corrosion/erosion evaluation were the vital components of the inspection. The image processing techniques and precise thickness measurement method were added to the digitized radiographs. For the digital image processing, a histogram matching algorithm and an edge detection method were used. After all, the resulted image showed an enhanced quality image of the original traces of the hammered design. The results showed that a good experimental setup of radiography along with the image processing technique can give a high quality radiographic image which is able to be used effectively for the identification of art antiques. The human evaluation results also confirmed the ability of the proposed method with a high degree of certainty.

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 (<6.5 km) low-velocity layer (shear wave velocity of ~3 km/s), which is ~20-30% slower than normal oceanic crustal velocities, between the subducted slab and the overriding North American 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

200 ps FWHM and 100 MHz repetition rate ultrafast gated camera for optical medical functional imaging

Science.gov (United States)

Uhring, Wilfried; Poulet, Patrick; Hanselmann, Walter; Glazenborg, René; Zint, Virginie; Nouizi, Farouk; Dubois, Benoit; Hirschi, Werner

2012-04-01

The paper describes the realization of a complete optical imaging device to clinical applications like brain functional imaging by time-resolved, spectroscopic diffuse optical tomography. The entire instrument is assembled in a unique setup that includes a light source, an ultrafast time-gated intensified camera and all the electronic control units. The light source is composed of four near infrared laser diodes driven by a nanosecond electrical pulse generator working in a sequential mode at a repetition rate of 100 MHz. The resulting light pulses, at four wavelengths, are less than 80 ps FWHM. They are injected in a four-furcated optical fiber ended with a frontal light distributor to obtain a uniform illumination spot directed towards the head of the patient. Photons back-scattered by the subject are detected by the intensified CCD camera; there are resolved according to their time of flight inside the head. The very core of the intensified camera system is the image intensifier tube and its associated electrical pulse generator. The ultrafast generator produces 50 V pulses, at a repetition rate of 100 MHz and a width corresponding to the 200 ps requested gate. The photocathode and the Micro-Channel-Plate of the intensifier have been specially designed to enhance the electromagnetic wave propagation and reduce the power loss and heat that are prejudicial to the quality of the image. The whole instrumentation system is controlled by an FPGA based module. The timing of the light pulses and the photocathode gating is precisely adjustable with a step of 9 ps. All the acquisition parameters are configurable via software through an USB plug and the image data are transferred to a PC via an Ethernet link. The compactness of the device makes it a perfect device for bedside clinical applications.

Photon attenuation by intensifying screens

International Nuclear Information System (INIS)

Holje, G.

1983-01-01

The photon attenuation by intensifying screens of different chemical composition has been determined. The attenuation of photons between 20 keV and 120 keV was measured by use of a multi-channel analyzer and a broad bremsstrahlung distribution. The attenuation by the intensifying screens was hereby determined simultaneously at many different monoenergetic photon energies. Experimentally determined attenuations were found to agree well with attenuation calculated from mass attenuation coefficients. The attenuation by the screens was also determined at various bremsstrahlung distributions, simulating those occurring behind the patient in various diagnostic X-ray examinations. The high attenuation in some of the intensifying screens form the basis for an analysis of the construction of asymmetric screen pairs. Single screen systems are suggested as a favourable alternative to thick screen pair systems. (Author)

Sensitometry of intensifying screen-film system for detection of yearly change of imaging quality factors

International Nuclear Information System (INIS)

Yoshida, Akira; Asahara, Masayoshi

2002-01-01

Systematic sensitometry of 20 green- and 25 blue-intensifying screens made in early 1980s and early 1990s was performed on their physical imaging qualities to evaluate their yearly change. Sensitometry was done with Toshiba KXO-1000 X-ray generator (Tube: Toshiba DRX-431HD, 80 kV, 20 mm-thick Al-filter), characteristic curve examination with KXO-15 (Tube: DRX-1603B, 80 kV, 0.5 mm Cu+4.0 mm Al), determination of modulation transfer function with KXO-15 (Tube: DRX-1303B, 80 kV, 2.0 mm Al), and Wiener spectrometry with Hitachi DH-158 (Tube: Hitachi UH-6GC-108DL, 80 kV, 20 mmAl). Reference screen was that reported by US Bureau of Radiological Health (1982) and Center for Devices and Radiological Health (196) and was obtained from Chicago University. There were products without yearly change, with increased sensitivity with unchanged resolution and noise level, with improved resolution, or with improved sensitivity. (K.H.)

Gonad doses for male patients from stomach examination and oral cholegraphy using the X-ray image intensifying technique and television fluoroscopy

International Nuclear Information System (INIS)

Steinbach, W.; Richter, K.; Koenig, W.; Menzel, B.; Reisinger, W.; Uhlich, F.

1979-01-01

The gonad dose was measured for male patients undergoing stomach examinations and oral cholegraphy by means of a diagnostic twelve pulse generator (TuR D 1500) and an X-ray apparatus 'Diagnost 100' (Philips-Mueller). In a small group of patients the gonad dose was ascertained per exposure to a 70 mm single spot film, to a 24 cm x 30 cm full size radiograph, and per minute of exposure to image intensifier fluoroscopy. The total gonad dose in both the diagnostic techniques was determined seperately in larger groups of patients. In stomach examination large size radiography led to a gonad dose 20 times higher than that obtained with the spot film technique, while exposure from cholegraphy was 10 times higher. The gonad dose per exposure of a single spot film was about 0.5 mrad. In examinations of the stomach the gonad dose from one minute fluroscopy was 18 times higher than the doses determined for a single spot film, and in cholegraphy it was 10 times higher. Supposing mean values of the number of radiographs and of the fluoroscopy time according to the conditions applied, the gonad dose in stomach examination from the film-screen technique is about twice that from the television image-intensifying technique. By comparison, oral cholegraphy exclusively performed by large-size radiography yielded about the same gonad dose as the spot film television technique. Total dose values determined separately confirmed these evaluations. (author)

Time-of-flight neutron Bragg-edge transmission imaging of microstructures in bent steel plates

Energy Technology Data Exchange (ETDEWEB)

Su, Yuhua, E-mail: yuhua.su@j-parc.jp [J-PARC Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai, Ibaraki 319-1195 (Japan); Oikawa, Kenichi; Harjo, Stefanus; Shinohara, Takenao; Kai, Tetsuya; Harada, Masahide; Hiroi, Kosuke [J-PARC Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai, Ibaraki 319-1195 (Japan); Zhang, Shuoyuan; Parker, Joseph Don [Neutron R& D Division, CROSS-Tokai, 162-1 Shirakata, Tokai, Ibaraki 319-1106 (Japan); Sato, Hirotaka [Faculty of Engineering, Hokkaido University, Sapporo 060-8628 (Japan); Shiota, Yoshinori; Kiyanagi, Yoshiaki [Graduate School of Engineering, Nagoya University, Nagoya, Aichi 464-8603 (Japan); Tomota, Yo [Research Center for Strategic Materials, National Institute for Materials Science, Tsukuba 305-0047 (Japan)

2016-10-15

Neutron Bragg-edge transmission imaging makes it possible to quantitatively visualize the two-dimensional distribution of microstructure within a sample. In order to examine its application to engineering products, time-of-flight Bragg-edge transmission imaging experiments using a pulsed neutron source were performed for plastically bent plates composed of a ferritic steel and a duplex stainless steel. The non-homogeneous microstructure distributions, such as texture, crystalline size, phase volume fraction and residual elastic strain, were evaluated for the cross sections of the bent plates. The obtained results were compared with those by neutron diffraction and electron back scatter diffraction, showing that the Bragg-edge transmission imaging is powerful for engineering use.

Remote defect imaging for plate-like structures based on the scanning laser source technique

Science.gov (United States)

Hayashi, Takahiro; Maeda, Atsuya; Nakao, Shogo

2018-04-01

In defect imaging with a scanning laser source technique, the use of a fixed receiver realizes stable measurements of flexural waves generated by laser at multiple rastering points. This study discussed the defect imaging by remote measurements using a laser Doppler vibrometer as a receiver. Narrow-band burst waves were generated by modulating laser pulse trains of a fiber laser to enhance signal to noise ratio in frequency domain. Averaging three images obtained at three different frequencies suppressed spurious distributions due to resonance. The experimental system equipped with these newly-devised means enabled us to visualize defects and adhesive objects in plate-like structures such as a plate with complex geometries and a branch pipe.

Soft x-ray imaging system for measurement of noncircular tokamak plasmas

International Nuclear Information System (INIS)

Fonck, R.J.; Reusch, M.; Jaehnig, K.P.; Hulse, R.; Roney, P.

1986-08-01

A soft x-ray camera and image processing system has been constructed to provide measurements of the internal shape of high temperature tokamak plasmas. The camera consists of a metallic-foil-filtered pinhole aperture and a microchannel plate image intensifier/convertor which produces a visible image for detection by a CCD TV camera. A wide-angle tangential view of the toroidal plasma allows a single compact camera to view the entire plasma cross section. With Be filters 12 to 50 μm thick, the signal from the microchannel plate is produced mostly by nickel L-line emissions which orignate in the hot plasma core. The measured toroidal image is numerically inverted to produce a cross-sectional soft x-ray image of the plasma. Since the internal magnetic flux surfaces are usually isothermal and the nickel emissivity depends strongly on the local electron temperature, the x-ray emission contours reflect the shape of the magnetic surfaces in the plasma interior. Initial results from the PBX tokamak experiment show clear differences in internal plasma shapes for circular and bean-shaped discharges

Imaging of soft and hard materials using a Boersch phase plate in a transmission electron microscope

Energy Technology Data Exchange (ETDEWEB)

Alloyeau, D., E-mail: alloyeau.damien@gmail.com [National Center for Electron Microscopy, Lawrence Berkeley National Laboratory, One Cyclotron Road, MS/72, Berkeley, CA 94720 (United States); Hsieh, W.K. [National Center for Electron Microscopy, Lawrence Berkeley National Laboratory, One Cyclotron Road, MS/72, Berkeley, CA 94720 (United States); Anderson, E.H.; Hilken, L. [Center for X-ray Optics, Lawrence Berkeley National Laboratory, Berkeley CA 94720 (United States); Benner, G. [Carl Zeiss NTS GmbH, Oberkochen 73447 (Germany); Meng, X. [Electrical Engineering and Computer Sciences, UC Berkeley, Berkeley, CA 94720-1770 (United States); Chen, F.R. [Department of Engineering and System Science, National Tsing Hua University, Hsinchu, Taiwan (China); Kisielowski, C. [National Center for Electron Microscopy, Lawrence Berkeley National Laboratory, One Cyclotron Road, MS/72, Berkeley, CA 94720 (United States)

2010-04-15

Using two levels of electron beam lithography, vapor phase deposition techniques, and FIB etching, we have fabricated an electrostatic Boersch phase plate for contrast enhancement of weak phase objects in a transmission electron microscope. The phase plate has suitable dimensions for the imaging of small biological samples without compromising the high-resolution capabilities of the microscope. A micro-structured electrode allows for phase tuning of the unscattered electron beam, which enables the recording of contrast enhanced in-focus images and in-line holograms. We have demonstrated experimentally that our phase plate improves the contrast of carbon nanotubes while maintaining high-resolution imaging performance, which is demonstrated for the case of an AlGaAs heterostructure. The development opens a new way to study interfaces between soft and hard materials.

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.

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.

Imaging plates for nuclear radiations

International Nuclear Information System (INIS)

Abe, Ken; Takebe, Masahiro

1997-01-01

Full text. The imaging plate (IP, hereafter) is a new opto-electronic X-ray film developed by Fuji Photo Film Co. Ltd., formed with a large area of thin flexible plastic plate coated with photo-estimulable storage phosphor (e.g. Ba F Br: Eu 2+ ). Recently, it has been found highly sensitive to soft X-ray (SR), soft electrons, and also usual alpha, beta, gamma rays and others, e.g. cosmic rays, energy heavy ions, and moreover neutrons through suitable converters inside or outside of the IP. Many types of IP are now used in various fields, such as medical examinations, auto-radiography in vivo/ in situ/ in vitro, X-ray/neutron diffraction/ radiography, electron microscopy. RI contamination, assay of ore. The IP has other striking performances, e.e. extremely low intrinsic noises, a high position resolution, high detection efficiency (100-1000 times) as high as an X-ray film), extremely wide dynamic range of dose (more than 10 5 ). Besides the thermal fading yet left unresolved materially, the only feature lacking and that one has ben longing for is the radiation identification by itself. We found out that the IP has a full potential ability of radiation identification in itself. One evidence found is that the ratio of the twin peaks of the PSL (photo-stimulated luminescence) excitation spectra indicates simply the particle energies, studied and now established. Another is that the photo-beaching provides the fluorescent responses different enough to discriminate the radiations, yet in progress with cyclotron experiments, into the usage of double labeled bio tracers

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.

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.

Dust Plate, Retina, Photograph: Imaging on Experimental Surfaces in Early Nineteenth-Century Physics.

Science.gov (United States)

Ramalingam, Chitra

2015-09-01

This article explores the entangled histories of three imaging techniques in early nineteenth-century British physical science, techniques in which a dynamic event (such as a sound vibration or an electric spark) was made to leave behind a fixed trace on a sensitive surface. Three categories of "sensitive surface" are examined in turn: first, a metal plate covered in fine dust; second, the retina of the human eye; and finally, a surface covered with a light-sensitive chemical emulsion (a photographic plate). For physicists Michael Faraday and Charles Wheatstone, and photographic pioneer William Henry Fox Talbot, transient phenomena could be studied through careful observation and manipulation of the patterns wrought on these different surfaces, and through an understanding of how the imaging process unfolded through time. This exposes the often-ignored materiality and temporality of epistemic practices around nineteenth-century scientific images said to be "drawn by nature."

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.

Comparison of dose and image quality of a Flat-panel detector and an image intensifier; Comparacao da dose e qualidade da imagem de um detector Flatpanel e um intensificador de imagem

Energy Technology Data Exchange (ETDEWEB)

Lazzaro, M.; Friedrich, B.Q.; Luz, R.M. da; Silva, A.M.M. da, E-mail: marcos.lazzaro@acad.pucrs.br [Pontificia Universidade Catolica do Rio Grande do Sul (PUC-RS), Porto Alegre, RS (Brazil)

2016-07-01

With the development of new technologies, have emerged new conversion methods of X-ray image, such as flat panel detectors. The aim of this work is the comparison of entrance surface air kerma (ESAK) and image quality between an image intensifier type of detector (A) and a flat panel (B). The ESAK was obtained by placing a ionization chamber under PMMA simulators of 10, 20 and 30 cm and the image quality was obtained by using the TOR {sup 18}FG simulator. The ESAK to the equipment A is higher when compared to the equipment B. The high contrast resolution is better for the equipment A for all thicknesses of simulators. The equipment A has low contrast resolution with a better viewing threshold for thicknesses of 10 and 20 cm, and a worse performance for 30 cm. It is concluded that the equipment B has ESAK smaller and despite having lower resolution, in almost all cases, have appropriate image quality for diagnosis. (author)

The use of BAS-TR imaging plates calibration in determining the resolving power of Fuji BAS-1800II image plate reader

Science.gov (United States)

Alnaimi, R.

2018-01-01

The importance of this work lies in assuring the reliability of the results obtained from both imaging plates type BAS-TR and Fuji Image Reader BAS-1800II as they are widely used in calculating essential x-ray sources parameters such as the source size, x-ray flux and brilliance, hence, the calibration presented in this work. For such quantitative analysis, a common practice used by many researchers, where Gold resolution meshes are utilised for such purpose, however not quite successful due to the transmission effect of high energy photons at their edges as well as the pixeling effect while magnifying the scanned image to secure the edge spread function (ESF) data. In contrast, the use of resolution test target (RTT) and wire mesh grid together with a set of test samples i.e. Stanley blades, Ta, Ti and Si wafer of 100, 300, 15, and 490 micron thickness respectively appeared to be efficient in determining IP pixel size and the resolution of the reader. Two different experiments were conducted using two different targets and lasers of very different performance. The first, was a 15 μm VHS video tape composed of Mylar as carrier film with Fe2O3 and CrO2 powder. Nd:YAG laser of long pulse 800 ps, 50 Hz repetition rate and single shot were utilised. Whereas, the second experiment were conducted on a 9μm C wire and a short pulse 500fs Cerberus single shot laser was used. The results obtained from both experiments were pretty much similar. The imaging plate spatial resolution was measured to be: 3.4 ± 0.2 pixels and a pixel size of 41.26 ± 1.4 μm, whereas the smallest resolvable object visible to the reader (1:1 imaging with magnification factor) was of order 140.3 ± 0.3 microns. This appeared to be worse by a factor of three which indicates the importance of the reader's calibration on a regular basis, and at the same time one has to reconsider any related work and calculation based upon the previous nominal values.

Upwards Intensifiers in the English, German and Croatian Language

Directory of Open Access Journals (Sweden)

Anita Pavić Pintarić

2014-12-01

Full Text Available This paper investigates the upwards intensifiers (adverbs of intensifying in the English, German and Croatian language. Intensity as an important human cognitive category, and language expressivity is differently treated in grammars and dictionaries of all three languages, especially with respect to different degrees of intensity. In this paper we argue that it is possible to model a typology of upwards adverb intensifiers in the three languages, according to their morphosyntactic and semantic aspects. When it comes to intensifiers, it is necessary to describe which collocates are modified by intensifiers and which semantic fields the collocates belong to. The results of the corpus analysis based on Harry Potter novels show that all the three languages express the category of the upwards intensity in the same way: the number of intensifiers is similar, the collocates mostly belong to the same semantic fields and word classes, they have similar syntactic functions.

An enhanced CCRTM (E-CCRTM) damage imaging technique using a 2D areal scan for composite plates

Science.gov (United States)

He, Jiaze; Yuan, Fuh-Gwo

2016-04-01

A two-dimensional (2-D) 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 actuator mounted on the composite plate and a laser Doppler vibrometer (LDV) for scanning a region to capture the scattered wavefield in the vicinity of the PZT. 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, the reflectivity coefficients of the delamination can be calculated and potentially related to damage severity. Comparisons are made in terms of damage imaging quality between 2-D areal scans and linear scans as well as between the proposed and existing imaging conditions. The experimental results show that the 2-D 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.

Radioisotope imaging using gamma-ray shadow hologram

International Nuclear Information System (INIS)

Kojima, Kazuhiko; Itaya, Gensei; Hisada, Kin-ichi.

1975-01-01

Use of holography for the imaging of radioisotope distribution, reported by Barrett, H.H. in 1972, has been marked as a new γ-ray imaging. Generally, in optical fields, holography was often used for recording and processing three dimensional images by coherent waves such as laser beams. However, γ-rays are incoherent and are not condensed by optical lenses. So it was necessary that the holograms of incoherent sources were formed without optical lenses. A method which records the shadows of on axis zone plate with a Fresnnel diffraction pattern was used for obtaining an incoherent hologram. This method has the advantages of improved resolution and γ-ray detection efficiency, and also has a constitution of this system which is simple and economical. But, the disadvantage is, that the process consists of two steps, forming holograms and reconstructing images. The fundamental problems of γ-ray holograms and the practicabilities of γ-ray imaging of this method were discussed. In this system medical x-ray films combined with industrial intensifying screens were used as detectors, and γ-ray shadow holograms were obtained for about 3 minutes. From the shadow holograms, images were reconstructed, using a parallel laser beams, (He-Ne laser, single mode, 6328 A, 1mW). The zone plate consisted of coaxial lead rings with 10 open zones. The aperture area of this zone plate collimator was several hundreds times larger than the pinhole, so the detection efficiency, of γ-rays was improved. Using sup(99m)Tc 10 mCi as a γ-ray source, an attempt was made to image points, English characters and thyroid phantoms, and these reconstructed images were shown. An image resolution of 3-5 mm was obtained in the reconstructed image of an object at a distance of 10 cm from the collimator. (auth.)

Comparative evaluation of image quality in computed radiology systems using imaging plates with different usage time

International Nuclear Information System (INIS)

Lazzaro, M.V.; Luz, R.M. da; Capaverde, A.S.; Silva, A.M. Marques da

2015-01-01

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)

Simplified quality control of radioactive seeds in sterile cartridge for prostate brachytherapy using an imaging plate and a collimator

International Nuclear Information System (INIS)

Saze, T.; Miyoshi, H.; Maezawa, H.; Kubota, M.; Furutani, S.; Nishitani, H.; Kawaguchi, Y.; Nakayama, S.; Ito, S.; Nishizawa, K.

2008-01-01

Image analyzer system and collimator has been successfully applied to calibrate simultaneously multiple 125 I seeds in a sterile cartridge. Seeds within the cartridge were placed on an imaging plate, and the imaging plate irradiated. To remove scatter radiation, and improve spatial resolution of seed images, this study used a specially designed collimator. The irradiated imaging plate was scanned using an image analyzer system, and radioactivity intensities of seed images were given in counts. Counts could be translated to profiles, and each seed within the cartridge was analyzed. It is observed that a good correlation between counts and total radioactivity of the seeds within the cartridge. Thus, using a least-squares line, it was possible to calibrate a seed with unknown apparent activity. By analyzing the profiles, it was possible not only to detect a mis calibrated seed in the cartridge from its relative difference in counts, but also to identify its position in the cartridge. Using an imaging analyzer system, all seeds in a cartridge could be calibrated in a sterile environment. (author)

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...... the reference wave distortion from long-range fields affecting electron holography....

Radioactivity distribution measurement of various natural material surfaces with imaging plate

International Nuclear Information System (INIS)

Mori, C.; Suzuki, T.; Koido, S.; Uritani, A.; Yanagida, K.; Wu, Y.; Nishizawa, K.

1996-01-01

Distribution images of natural radioactivity in natural materials such as vegetables were obtained by using Imaging Platc. In ssuch cases, it is necessary to reduce background radiation intensity by one order or more. Graded shielding is very important. Espacially, the innermost surface of a shielding box sshould be covered with acrylic rein plate. We obtained natural radioactivity distribution images of vegetable, sea food, mea etc. Most β-rays emitted from 40 K print the radioactivity distribution image. Comparison between γ-ray intensity of KCL solution measured with HPGe detector and that of natural material specimen gave the radioactivity around 0.06- 0.04Bq/g depending on the kind and the part of specimens. (author). 6 refs., 5 figs., 1 tab

Study of secondary X-rays from radiographic intensifying screens

International Nuclear Information System (INIS)

Barroso, R.C.; Eichler, J.; Lopes, R.T.; Cardoso, S.C.

1998-01-01

To reduce the radiation dose in radiology, fluorescent intensifying screens for X-ray films are used. They produce visible light which increases the efficiency of the film. In addition, there are two other effects that will degrade the image resolution. First, the gadolinium present in the screens produces X-rays isotropically. Second, the primary radiation can be scattered elastically (Rayleigh scattering) and inelastically (Compton scattering). The intensity and angular distribution of these secondary radiation were measured, showing that the ratio of secondary-to-primary radiation incident on the X-ray film is about 16%. (orig.)

Precise natural radiography of seafloor sedimentary cores by using imaging plate

International Nuclear Information System (INIS)

Sugihara, Makoto; Tsuchiya, Noriyoshi

2007-01-01

The radiation measurement for seafloor sedimentary cores was carried out by using the Imaging Plate (IP). The precise natural radiography was obtained with 48 hours (exposure time) in a shield box. Layered structures of seafloor sediments that have relatively low radioactivity like biogenic matters could be detected by autoradiography, and it was possible to identify optically unclear layers of sediments with differences of radiation characteristics. The detection limit of thickness of suspended particle layers like volcanic ashes might be sub millimeters. It was possible to identify the pinpoint position where radioactive mineral emitted α-rays at the surface of sample. Identification of pinpoint position could be possible suppose radioactive minerals that emits α-ray exposed at the surface of sample. Distribution of dose (PSL value of IP) was related to CT value (X-ray CT), which indicates dose of sedimentary core have relationships with density and atomic number of sediments. The natural radiography for seafloor sediments cores by using the Imaging Plate is considered to be a powerful new tool as a non-destructive core analysis. (author)

Differences of X-ray exposure between X-ray diagnostics with a conventional X-ray screen-system and with an image-intensifier-television-unit

International Nuclear Information System (INIS)

Loehr, H.; Vogel, H.; Reinhart, J.; Jantzen, R.

1977-01-01

During X-ray diagnostics of patients in the II. Medizinische Poliklinik the X-ray exposure was determined. It corresponded to the data described in literature. Two groups were compared: 518 patients examined with a conventional X-ray screen-system and 642 patients examined with an image-intensifier-television-system. The results demonstrated that with exception of thoracical X-ray examination the replacing of the old system by the television system brought a remarkable increase of the X-ray exposure. The doses depended of the patients constitution to a high degree. (orig.) [de

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.

Imaging system for obtaining space- and time-resolved plasma images on TMX

International Nuclear Information System (INIS)

Koehler, H.A.; Frerking, C.E.

1980-01-01

A Reticon 50 x 50 photodiode array camera has been placed on Livermore's Tandem Mirror Experiment to view a 56-cm diameter plasma source of visible, vacuum-ultraviolet, and x-ray photons. The compact camera views the source through a pinhole, filters, a fiber optic coupler, a microchannel plate intensifier (MCPI), and a reducer. The images are digitized (at 3.3 MHz) and stored in a large, high-speed memory that has a capacity of 45 images. A local LSI-11 microprocessor provides immediate processing and display of the data. The data are also stored on floppy disks that can be further processed on the large Livermore Computer System. The temporal resolution is limited by the fastest MCPI gate. The number of images recorded is determined by the read-out time of the Reticon camera (minimum 0.9 msec). The spatial resolution of approximately 1.4 cm is fixed by the geometry and the pinhole of 0.025 cm. Typical high-quality color representation of some plasma images are included

Spatial resolution of imaging plate with flash X-rays and its utilization for radiography

Energy Technology Data Exchange (ETDEWEB)

Shaikh, A. M., E-mail: shaikham@barc.gov.in [Physics Group, Bhabha Atomic Research Centre, Mumbai-400085 (India); Romesh, C.; Kolage, T. S.; Sharma, Archana [Accelerator and Pulsed Power Division, Bhabha Atomic Research Centre, Mumbai-400085 (India)

2015-06-24

A flash X-ray source developed using pulsed electron accelerator with electron energy range of 400keV to 1030keV and a field emission cathode is characterized using X-ray imaging plates. Spatial resolution of the imaging system is measured using edge spread function fitted to data obtained from radiograph of Pb step wedge. A spatial resolution of 150±6 µm is obtained. The X-ray beam size is controlled by the anode-cathode configuration. Optimum source size of ∼13±2 mm diameter covering an area with intensity of ∼27000 PSL/mm{sup 2} is obtained on the imaging plate kept at a distance of ∼200 mm from the tip of the anode. It is used for recording radiographs of objects like satellite cable cutter, aero-engine turbine blade and variety of pyro-devices used in aerospace industry.

Application of an image intensifier to the study on hadrons in air shower, 4

International Nuclear Information System (INIS)

Tsushima, Itsuro; Kawasumi, Norio; Hashimoto, Katsumi; Machida, Masaharu

1975-01-01

As the apparatus for observing cosmic ray air shower, the particle detection apparatus combining spark chamber, scintillator and photomultiplier tube is frequently used, but the exact detection of particle number is impossible with it when particle density is large. The authors have carried out the experiment to measure nuclear active particles in air shower and to grasp the central part of air shower as energy flow by utilizing an image intensifier tube. On the roof of building S, a laboratory was built, and a core detector of 2 m x 2 m area, 13 AS detectors of 0.25 m 2 and an AS detector of 1 m 2 were installed. The gate of the II was opened by utilizing coincidence pulses, and the position and amount of scintillation in the core detector was taken into a camera through the II. The time of observation was 289 hours, and the time of II operation was 113 hours. Total number of air shower recorded was 218 cases, and the centers of 120 cases among them were determined in the AS detectors at four corners. The centers of 39 cases were within the area of the core detector. In the coincident counting of air shower and burst carried out in the present experiment, the total delay time from the arrival of air shower to the gate pulse actuating the II was 1.6 sec. The core of air shower of about 10 6 size and 1.3 age was caught by this method. The problems for future are the determination of core position for the air shower of smaller size, and the meaning of spot images of II. (Kako, I.)

Possibilities of reducing radiation doses in spinograms of adolescents by means of most intensifying screens and compensating screens

Energy Technology Data Exchange (ETDEWEB)

Pollaehne, W; Brandt, G A [Staedtisches Klinikum Berlin-Buch (German Democratic Republic)

1980-01-01

Most intensifying screens based on CaWO/sub 4/ and LaOBr/sub 2/ or combinations of them were used in radiography of both the thoracic and the lumbar parts of the spines of adolescents. The results obtained were compared with those achieved by means of screens usually used for spinograms. Radiation exposure was reduced, on an average by 30-40%, when most intensifying screens were used, the image quality being the same. The introduction of high-speed superscreens is pressingly recommended.

Development of 99mTc imaging method using multiple imaging plates for reduction of patient's dose

International Nuclear Information System (INIS)

Ito, Shigeki; Nishizawa, Kunihide; Ariga, Eiji; Saze, Takuya

2008-01-01

A system for taking static thyroid 99m Tc images was devised by using multiple imaging plates (IPs) and a low energy high resolution collimator. Sensitivity was represented by using lower detection limits (LDL). The sensitivity and resolution of IP systems using a collimator 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 9 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 static nuclear imaging devices as same as a gamma camera. (author)

Intensifying screens in transaxial tomography

International Nuclear Information System (INIS)

Debelder, M.H.; Bollen, R.H.

1981-01-01

This patent claim by Agfa-Gevaert relates to a method for the production of transaxial tomographs, a combination of materials therefor and X-ray intensifying screens incorporating at least one reflecting element for use in transaxial tomography, wherein the exposure of a photographic silver halide emulsion material proceeds at an angle within the range of 2 0 to 10 0 in conjunction with an X-ray fluorescent intensifying screen including an ultra-violet and/or visible radiation reflective coating or sheet to increase the radiation output of the screen and to reduce the exposure time and radiation dose e.g. in medical X-ray applications. (author)

Interlaced zone plate optics for hard X-ray imaging in the 10 nm range

Science.gov (United States)

Mohacsi, Istvan; Vartiainen, Ismo; Rösner, Benedikt; Guizar-Sicairos, Manuel; Guzenko, Vitaliy A.; McNulty, Ian; Winarski, Robert; Holt, Martin V.; David, Christian

2017-03-01

Multi-keV X-ray microscopy has been particularly successful in bridging the resolution gap between optical and electron microscopy. However, resolutions below 20 nm are still considered challenging, as high throughput direct imaging methods are limited by the availability of suitable optical elements. In order to bridge this gap, we present a new type of Fresnel zone plate lenses aimed at the sub-20 and the sub-10 nm resolution range. By extending the concept of double-sided zone plate stacking, we demonstrate the doubling of the effective line density and thus the resolution and provide large aperture, singlechip optical devices with 15 and 7 nm smallest zone widths. The detailed characterization of these lenses shows excellent optical properties with focal spots down to 7.8 nm. Beyond wave front characterization, the zone plates also excel in typical imaging scenarios, verifying their resolution close to their diffraction limited optical performance.

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.

Colour-the-INSight : Combining a direct view rifle sight with fused intensified and thermal imagery

NARCIS (Netherlands)

Hogervorst, M.A.; Jansen, C.; Toet, A.; Bijl, P.; Bakker, P.J.; Hiddema, A.C.; Vliet, S.F. van

2012-01-01

We present the design and evaluation of a new demonstrator rifle sight viewing system containing direct view, red aim point and fusion of an (uncooled, LWIR) thermal sensor with a digital image intensifier. Our goal is to create a system that performs well under a wide variety of (weather)

Feasibility of in vivo thyroid {sup 131}I monitoring with an imaging plate

Energy Technology Data Exchange (ETDEWEB)

Hirota, Masahiro; Saze, Takuya; Ogata, Yoshimune; Nishizawa, Kunihide E-mail: nishizawa@nucc.cc.nagoya-u.ac.jp

2001-10-01

A new in vivo thyroid {sup 131}I monitoring method was devised by using an imaging plate (IP). A thyroid image obtained with a realistic neck-thyroid phantom showed a unique shape characteristic of the thyroid gland. A {sup 131}I thyroid imaging allows visual confirmation of thyroid accumulation of {sup 131}I. The detection limit of the IP system of 290 Bq was about ((1)/(100)) of the screening level of 30 kBq in cases of public emergencies. The IP system is applicable for thyroid {sup 131}I monitoring.

Depth of focus enhancement of a modified imaging quasi-fractal zone plate.

Science.gov (United States)

Zhang, Qinqin; Wang, Jingang; Wang, Mingwei; Bu, Jing; Zhu, Siwei; Gao, Bruce Z; Yuan, Xiaocong

2012-10-01

We propose a new parameter w for optimization of foci distribution of conventional fractal zone plates (FZPs) with a greater depth of focus (DOF) in imaging. Numerical simulations of DOF distribution on axis directions indicate that the values of DOF can be extended by a factor of 1.5 or more by a modified quasi-FZP. In experiments, we employ a simple object-lens-image-plane arrangement to pick up images at various positions within the DOF of a conventional FZP and a quasi-FZP, respectively. Experimental results show that the parameter w improves foci distribution of FZPs in good agreement with theoretical predictions.

A new method of the light irradiation image by the computed radiography (imaging plate) system

International Nuclear Information System (INIS)

Aiba, Susumu; Nishi, Katsuki.

1997-01-01

There are two method for the purpose of diagnosing medically by using gamma-ray light irradiation image. One is to use of the scintillation camera for gamma-ray, the other is to use of the photostimulable luminescence point by the secondary excitation of the image plate (IP) system for X-ray. The standpoint of the spatial resolution at the total medical image, using gamma-ray, the first can get the image on a short time, but the first is a poor image quality, and the second is good image quality, but the second can get the image on a long time, because of insensitive to gamma-ray. We report on the improvement for IP's week point by our proposal method, and by our clinical and quantitative analysis data, to use the highly efficient IP (ST-III). We make the improvement on the imaging time (from 30 minutes to 20 minutes), and the inprocessing time (from 33-50 minutes to 27 minutes) for a former method on an organism. We strongly believe that our convenience improvement method, and our clinical quantitative analysis data can contribute to the wide application as well as the quality up for the clinical diagnosis to use gamma-ray. (author)

Evaluation and reduction of magnetic resonance imaging artifacts induced by distinct plates for osseous fixation: an in vitro study @ 3T.

Science.gov (United States)

Rendenbach, Carsten; Schoellchen, Maximilian; Bueschel, Julie; Gauer, Tobias; Sedlacik, Jan; Kutzner, Daniel; Vallittu, Pekka K; Heiland, Max; Smeets, Ralf; Fiehler, Jens; Siemonsen, Susanne

2018-05-02

To analyze Magnetic Resonance Imaging (MRI) artifact induced at 3 Tesla by bioresorbable, titanium and glass fiber reinforced composite (GFRC) plates for osseous reconstruction. Fixation plates including bioresorbable polymers (Inion CPS, Inion Oy, Tampere, Finland; Rapidsorb, DePuy Synthes, Umkirch, Germany; Resorb X, Gebrueder KLS Martin GmbH, Tuttlingen, Germany), Glass fiber reinforced composite (Skulle Implants Oy, Turku, Finland) and titanium plates of varying thickness and design (DePuy Synthes, Umkirch, Germany) were embedded in agarose gel and a 3T MRI was performed using a standard protocol for head and neck imaging including T1w and T2w sequences. Additionally, different artifact reducing sequence techniques (slice encoding for metal artifact reduction (SEMAC) & ultrashort echotime (UTE)) were used and their impact on the extent of artifacts evaluated for each material. All titanium plates induced significantly more artefacts than resorbable plates in T1w and T2w sequences. Glass fiber-reinforced composites induced the least artefacts in both sequences. The total extent of artefacts increased with plate thickness and height. Plate thickness had no influence on the percentage of overestimation in all three dimensions. Titanium induced artefacts were significantly reduced by both artifact reducing sequence techniques. Polylactide, glass fiber-reinforced composite and magnesium plates produce less susceptibility artefacts in MRI compared to titanium, while the dimensions of titanium plates directly influence artifact extension. SEMAC and UTE significantly reduce metal artefacts at the expense of image resolution.

C.C.D. readout of a picosecond streak camera with an intensified C.C.D

International Nuclear Information System (INIS)

Lemonier, M.; Richard, J.C.; Cavailler, C.; Mens, A.; Raze, G.

1984-08-01

This paper deals with a digital streak camera readout device. The device consists in a low light level television camera made of a solid state C.C.D. array coupled to an image intensifier associated to a video-digitizer coupled to a micro-computer system. The streak camera images are picked-up as a video signal, digitized and stored. This system allows the fast recording and the automatic processing of the data provided by the streak tube

Guided-wave tomographic imaging of plate defects by laser-based ultrasonic techniques

Energy Technology Data Exchange (ETDEWEB)

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

2016-12-15

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.

Modulated electron-multiplied fluorescence lifetime imaging microscope: all-solid-state camera for fluorescence lifetime imaging.

Science.gov (United States)

Zhao, Qiaole; Schelen, Ben; Schouten, Raymond; van den Oever, Rein; Leenen, René; van Kuijk, Harry; Peters, Inge; Polderdijk, Frank; Bosiers, Jan; Raspe, Marcel; Jalink, Kees; Geert Sander de Jong, Jan; van Geest, Bert; Stoop, Karel; Young, Ian Ted

2012-12-01

We have built an all-solid-state camera that is directly modulated at the pixel level for frequency-domain fluorescence lifetime imaging microscopy (FLIM) measurements. This novel camera eliminates the need for an image intensifier through the use of an application-specific charge coupled device design in a frequency-domain FLIM system. The first stage of evaluation for the camera has been carried out. Camera characteristics such as noise distribution, dark current influence, camera gain, sampling density, sensitivity, linearity of photometric response, and optical transfer function have been studied through experiments. We are able to do lifetime measurement using our modulated, electron-multiplied fluorescence lifetime imaging microscope (MEM-FLIM) camera for various objects, e.g., fluorescein solution, fixed green fluorescent protein (GFP) cells, and GFP-actin stained live cells. A detailed comparison of a conventional microchannel plate (MCP)-based FLIM system and the MEM-FLIM system is presented. The MEM-FLIM camera shows higher resolution and a better image quality. The MEM-FLIM camera provides a new opportunity for performing frequency-domain FLIM.

Four-frame gated optical imager with 120-ps resolution

International Nuclear Information System (INIS)

Young, P.E.; Hares, J.D.; Kilkenny, J.D.; Phillion, D.W.; Campbell, E.M.

1988-04-01

In this paper we describe the operation and applications of a framing camera capable of four separate two-dimensional images with each frame having a 120-ps gate width. Fast gating of a single frame is accomplished by using a wafer image intensifier tube in which the cathode is capacitively coupled to an external electrode placed outside of the photocathode of the tube. This electrode is then pulsed relative to the microchannel plate by a narrow (120 ps), high-voltage pulse. Multiple frames are obtained by using multiple gated tubes which share a single bias supply and pulser with relative gate times selected by the cable lengths between the tubes and the pulser. A beamsplitter system has been constructed which produces a separate image for each tube from a single scene. Applications of the framing camera to inertial confinement fusion experiments are discussed

Application of an imaging plate system to in vivo thyroid 131I monitoring

International Nuclear Information System (INIS)

Hirota, M.; Saze, T.; Nishizawa, K.

2002-01-01

An imaging plate (IP) system was applied to in vivo thyroid radioactive iodine 131 ( 131 I) monitoring. Thyroid contamination by 131 I occurs when medical staffs and patient's families take in 131 I used as treatment agent for thyroid cancer and hyperthyroidism in nuclear medicine, inhabitants take in 131 I released into environment by an accident of nuclear facilities, or worker take in 131 I used by experiment of research. The IP system is a two-dimensional integrating radiation detector which is a plate thinly coated plastic sheet with a kind of phosphore. The IP was exposed to a neck-thyroid phantom loaded 131 I aqueous solution. The IP system displayed a thyroid image that reflects a unique shape characteristic of the thyroid gland. A 131 I thyroid imaging allows visual confirmation of thyroid contamination by 131 I. The counting efficiency was approximately constant when neck diameter, thyroid volume and prethyroid tissue thickness varied within the normal adult. The detection limit of 450Bq was about 1/65 of the screening level of 30kBq. The IP system is applicable for thyroid 131 I monitoring

Calibration of BAS-TR image plate response to high energy (3-300 MeV) carbon ions

Science.gov (United States)

Doria, D.; Kar, S.; Ahmed, H.; Alejo, A.; Fernandez, J.; Cerchez, M.; Gray, R. J.; Hanton, F.; MacLellan, D. A.; McKenna, P.; Najmudin, Z.; Neely, D.; Romagnani, L.; Ruiz, J. A.; Sarri, G.; Scullion, C.; Streeter, M.; Swantusch, M.; Willi, O.; Zepf, M.; Borghesi, M.

2015-12-01

The paper presents the calibration of Fuji BAS-TR image plate (IP) response to high energy carbon ions of different charge states by employing an intense laser-driven ion source, which allowed access to carbon energies up to 270 MeV. The calibration method consists of employing a Thomson parabola spectrometer to separate and spectrally resolve different ion species, and a slotted CR-39 solid state detector overlayed onto an image plate for an absolute calibration of the IP signal. An empirical response function was obtained which can be reasonably extrapolated to higher ion energies. The experimental data also show that the IP response is independent of ion charge states.

New technique for number-plate recognition

Science.gov (United States)

Guo, Jie; Shi, Peng-Fei

2001-09-01

This paper presents an alternative algorithm for number plate recognition. The algorithm consists of three modules. Respectively, they are number plate location module, character segmentation module and character recognition module. Number plate location module extracts the number plate from the detected car image by analyzing the color and the texture properties. Different from most license plate location methods, the algorithm has fewer limits to the car size, the car position in the image and the image background. Character segmentation module applies connected region algorithm both to eliminate noise points and to segment characters. Touching characters and broken characters can be processed correctly. Character recognition module recognizes characters with HHIC (Hierarchical Hybrid Integrated Classifier). The system has been tested with 100 images obtained from crossroad and parking lot, etc, where the cars have different size, position, background and illumination. Successful recognition rate is about 92%. The average processing time is 1.2 second.

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

International Nuclear Information System (INIS)

Jeong, Hyunjo; Cho, Sungjong; 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 0 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. (fundamental areas of phenomenology(including applications))

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.

Chemical nickel plating in tartrate solutions with borohydride reducing agent

International Nuclear Information System (INIS)

Plokhov, V.A.

1986-01-01

The authors investigate the influence of various factors on the rate of chemical nickel plating in strongly alkaline tartrate solutions with a borohydride reducing agent. After 30 min of the process of nickel plating, the final concentration of sodium borohydride decreases to 0.26 g/liter, leading to stoppage of the process. The nickel plating process can be intensified by increasing the concentration of sodium hydroxide in the solution, suppressing hydrolysis of borohydride, and also by introducing additives which suppress hydrolysis of borohydride. For chemical deposition of nickel-boron coatings from tartrate solutions the authors recommend the following composition (g/liter): nickel chloride 15-25, Rochelle salt 450-550, sodium hydroxide 140-160, sodium borohydride 0.8-1.0, thallium nitrate 0.003-0.008. The process temperature is 92-95 C, and the deposition rate is 4-6 um/h

Influence of phantom and tube voltage in fluoroscopy on image intensifier (I.I.) incident dose rate

International Nuclear Information System (INIS)

Seguchi, Shigenobu; Ishikawa, Yoshinobu; Kuwahara, Kazuyoshi; Morita, Miki; Mizuno, Shouta; Nakamura, Akio

1999-01-01

We examined the influence of phantoms and tube voltage in fluoroscopy on the image intensifier (I.I.) conversion factor. We used 20-cm-thick acrylic resin, 20 mm aluminum, and 1.5 mm copper, which are generally used as phantoms in the measurement of I.I. incident dose rate. We measured I.I. incident dose rate and conversion factor under conditions in which the range of tube voltage was from 60 kV to 120 kV. The result showed that the conversion factor is influenced by the type of phantom, with copper showing the highest value, aluminum second, and acrylic the smallest under the same condition of aluminum at half value layer. It was determined that conversion factor depends on tube voltage and has peaks from 80-100 kV. The location and height of the peak are influenced by the type of phantom. Therefore, I.I. incident dose rate is influenced by both the type of phantom and tube voltage under automatic brightness control fluoroscopy. Unification of phantoms and tube voltage is necessary for long-term evaluation of I.I. incident dose rate. (author)

MT2D Inversion to Image the Gorda Plate Subduction Zone

Science.gov (United States)

Lubis, Y. K.; Niasari, S. W.; Hartantyo, E.

2018-04-01

The magnetotelluric method is applicable for studying complicated geological structures because the subsurface electrical properties are strongly influenced by the electric and magnetic fields. This research located in the Gorda subduction zone beneath the North American continental plate. Magnetotelluric 2D inversion was used to image the variation of subsurface resistivity although the phase tensor analysis shows that the majority of dimensionality data is 3D. 19 MT sites were acquired from EarthScope/USArray Project. Wepresent the image of MT 2D inversion to exhibit conductivity distribution from the middle crust to uppermost asthenosphere at a depth of 120 kilometers. Based on the inversion, the overall data misfit value is 3.89. The Gorda plate subduction appears as a high resistive zone beneath the California. Local conductive features are found in the middle crust downward Klamath Mountain, Bonneville Lake, and below the eastern of Utah. Furthermore, mid-crustal is characterized by moderately resistive. Below the extensional Basin and Range province was related to highly resistive. The middle crust to the uppermost asthenosphere becomes moderately resistive. We conclude that the electrical parameters and the dimensionality of datain the shallow depth(about 22.319 km) beneath the North American platein accordance with surface geological features.

Coating Thickness Measurement of the Simulated TRISO-Coated Fuel Particles using an Image Plate and a High Resolution Scanner

International Nuclear Information System (INIS)

Kim, Woong Ki; Kim, Yeon Ku; Jeong, Kyung Chai; Lee, Young Woo; Kim, Bong Goo; Eom, Sung Ho; Kim, Young Min; Yeo, Sung Hwan; Cho, Moon Sung

2014-01-01

In this study, the thickness of the coating layers of 196 coated particles was measured using an Image Plate detector, high resolution scanner and digital image processing techniques. The experimental results are as follows. - An X-ray image was acquired for 196 simulated TRISO-coated fuel particles with ZrO 2 kernel using an Image Plate with high resolution in a reduced amount of time. - We could observe clear boundaries between coating layers for 196 particles. - The geometric distortion error was compensated for the calculation. - The coating thickness of the TRISO-coated fuel particles can be nondestructively measured using X-ray radiography and digital image processing technology. - We can increase the number of TRISO-coated particles to be inspected by increasing the number of Image Plate detectors. A TRISO-coated fuel particle for an HTGR (high temperature gas-cooled reactor) is composed of a nuclear fuel kernel and outer coating layers. The coating layers consist of buffer PyC (pyrolytic carbon), inner PyC (I-PyC), SiC, and outer PyC (O-PyC) layer. The coating thickness is measured to evaluate the soundness of the coating layers. X-ray radiography is one of the nondestructive alternatives for measuring the coating thickness without generating a radioactive waste. Several billion particles are subject to be loaded in a reactor. A lot of sample particles should be tested as much as possible. The acquired X-ray images for the measurement of coating thickness have included a small number of particles because of the restricted resolution and size of the X-ray detector. We tried to test many particles for an X-ray exposure to reduce the measurement time. In this experiment, an X-ray image was acquired for 196 simulated TRISO-coated fuel particles using an image plate and high resolution scanner with a pixel size of 25Χ25 μm 2 . The coating thickness for the particles could be measured on the image

Gabor zone-plate apertures for imaging with the mercuric iodide gamma-ray camera

Energy Technology Data Exchange (ETDEWEB)

Patt, B E [EG and G Energy Measurements, Inc., Goleta, CA (USA); Meyyappan, A; Cai, A; Wade, G [California Univ., Santa Barbara (USA). Dept. of Electrical and Computer Engineering

1990-12-20

Gabor zone-plate (GZP) apertures have been developed for use in EG and G EM's mercuric iodide (HgI{sub 2}) gamma-ray camera. The purpose of such an aperture is to increase efficiency, while maintaining good resolution. The GZP is similar to the Fresnel zone plate (FZP) but it has continuous transitions between opaque and transparent regions. Because there are no sharp transitions in the transmission, the inherent interference noise in GZP imaging is lower than that in FZP imaging. GZP parameters were chosen by considering the effects of constraints such as detector pixel size, number of pixels, minimum field of view required, maximum angle of incidence tolerated, and the Nyquist criterion for the minimum sampling rate. As a result an aperture was designed and fabricated with eight zones and a diameter of 3 cm. Lead was chosen as the aperture medium due to its high attenuation coefficient. Experimental data were obtained from the camera with the above GZP aperture. The point-spread function was determined and compared to the calculated response. Excellent agreement was obtained. The reconstruction process involves simulating, by computer, planar-wave illumination of a scaled transparency of the image and recording the intensity pattern at the focal plane. (orig.).

Coded aperture imaging and the introduction of the modulated zone plate in nuclear medicine

International Nuclear Information System (INIS)

Berg, C.J.M. van den

1976-01-01

Imaging radioactive distributions is an elementary problem in nuclear medicine. There are no media with refracting properties large enough to obtain a gamma lens. At this moment the images in nuclear medicine are produced with help of collimators. The disadvantages of the use of collimators are: limited resolution; low efficiency; only a small fraction of the total of the emitted radiation is detected; without special techniques a collimator cannot produce tomographic images. Recent developments of coded aperture imaging are trying to meet these disadvantages. One of the coded apertures is the Fresnel Zone Plate. In order to understand its use some of its optical properties are briefly discussed

Fast neutron radiography using photoluminescent imaging plates

International Nuclear Information System (INIS)

Rant, J.; Kristof, E.; Balasko, M.; Stade, J.

1999-01-01

Fast neutron radiography (FNR) and resonance neutron radiography (RNR) are complementary to the conventional radiography with high energy gamma-rays or brems-strahlung radiation used for the inspection of thick metal objects. In both non-destructive methods, the contrast sensitivity and the penetration power can be improved by using higher energy neutrons. At present direct techniques based either n Solid State Nuclear Track detectors (SSNTDs) or scintillating screens and transfer techniques using activation threshold detectors and radiographic films are applied for the detection of fast neutron images. Rather low detection sensitivity of film and SSNTD based fast neutron imaging methods and also rather poor inherent image contrast of SSNTD pose a problem for FNR in the fast neutron energy region 1-15 MeV interesting for NDT. For more efficient detection of fast neutron images the use of novel highly sensitive photoluminescent imaging plates (IP) in combination with threshold at the KFKI research reactor. The conventional IP produced by FUJI Photo Film Co. for the detection of beta and X-ray radiation were used. The threshold activation detectors were the reactions 115 In(n, n') 115m In, 64 Zn(n,p) 64 Cu, 56 Fe(n, p) 56 Mn, 24 Mg(n, p) 24 Na and 27 Al(n, α) 24 Na. These threshold reactions cover the fast neutron energy region between 0,7 MeV and 12 MeV. Pure, commercially available metals 0,1 mm to 0,25 mm thick made of In, Zn, Fe, Mg and Al were used as converter screens. The very high sensitivity of IP, the linearity of their response over 5 decades of exposure dose and the high dynamic digitalisation latitude enabled fast neutron radiography of image quality comparable to the quality of thermal NR. In our experimental conditions (φ n ∼ 10 8 n/cm 2 s, R Cd ∼ 2) the neutron exposure and IP exposure periods were still practical and comparable to the half life of the corresponding reaction products (half an hour to several hours). Even with the 27 Al(n.α) 24

On the Performance of X-ray Imaging Plates in Gamma Radiography employing Reactor-produced Radioisotopes

Science.gov (United States)

Silvani, Maria Ines; de Almeida, Gevaldo L.; Furieri, Rosanne C.; Lopes, Ricardo T.

2011-08-01

Gamma-radiography employing radiographic films is a well established technique for non-destructive assays. The advent of X-ray sensitive Imaging Plates opens up new possibilities to apply this technique thanks to the advantages exhibited by this new device. Indeed, besides a sensitivity about 20 times higher then the conventional photographic film, requiring thus a shorter exposure time, it does not require a dark room for a cumbersome and time-consuming chemical processing associated to the development, an can be erased to be reused many times. Moreover, its development carried out by means of a laser beam produces digitalized images which can be promptly stored in a computer. Although its resolution is still poorer than that of the conventional film, those advantages overwhelms this specific parameter when it is not an essential feature for the intended application. This work evaluates the feasibility of employing X-ray Imaging Plates as detector for higher photon energies as those emitted by reactor-produced radioisotopes. Within this frame, radioisotopes such as 198Au and 56Mn, produced at the Argonauta research reactor in the Instituto de Engenharia Nuclear-CNEN have been employed as sources to acquire radiographic images of several pieces of equipment, devices and components. In order to keep the source appearance—with regard to the detector—as punctual as possible, reducing hence the penumbra effect, the mass of the irradiated material had to be limited. Therefore, due to the low neutron flux available at the main port of the reactor, the exposure times have to be extended along several hours or even a couple of days in order to reach an image with adequate contrast. This demand, nevertheless, does not constitute a serious hindrance as the exposure process can be carried out without any intervention or surveillance. Results have shown that in spite of the higher photon energies used, surpassing the X-ray range for which the imaging plates have been

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.

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.

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.

2009-11-01

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 décollement. Western Java, however, differs markedly from margins such as Nankai or Barbados, where a uniform, continuous décollement 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 décollement 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 décollement and terminates at the sea floor and which potentially contributes to tsunami generation during co-seismic activity.

Pyramidal approach to license plate segmentation

Science.gov (United States)

Postolache, Alexandru; Trecat, Jacques C.

1996-07-01

Car identification is a goal in traffic control, transport planning, travel time measurement, managing parking lot traffic and so on. Most car identification algorithms contain a standalone plate segmentation process followed by a plate contents reading. A pyramidal algorithm for license plate segmentation, looking for textured regions, has been developed on a PC based system running Unix. It can be used directly in applications not requiring real time. When input images are relatively small, real-time performance is in fact accomplished by the algorithm. When using large images, porting the algorithm to special digital signal processors can easily lead to preserving real-time performance. Experimental results, for stationary and moving cars in outdoor scenes, showed high accuracy and high scores in detecting the plate. The algorithm also deals with cases where many character strings are present in the image, and not only the one corresponding to the plate. This is done by the means of a constrained texture regions classification.

Neutron stress measurement using image plate and the cos α method

International Nuclear Information System (INIS)

Sasaki, Toshihiko; Hirose, Yukio; Minakawa, Nobuaki; Morii, Yukio

2004-01-01

A new type of the neutron stress measurement method, in which the stress is determined by the cos α method, was studied. A neutron image plate was used in this study for detecting the diffraction image. Steel specimens of 5 mm thickness were used for the tensile stress test. The stresses obtain from the experiment showed one-to-one ratio with respect to the applied stresses, though the misfit stress of about 400 MPa was also observed in the result. A simple correction technique for calibrating raw data was proposed to obtain the true stress. A simulation study was carried out to check the experimental result on the peak positions in the diffraction ring and the stress calculation by the cos α method. (author)

Fluorescent intensifying screens: contribution of secondary X-rays

International Nuclear Information System (INIS)

Barroso, R.C.; Goncalves, O.D.; Eichler, J.; Lopes, R.T.; Cardoso, S.C.

1996-01-01

The counting rate and angular distribution of secondary X-rays produced by fluorescent intensifying screens are studied. A source of 241 Am - gamma radiation of 59.54 keV - is used. Fluorescent intensifying screens reduce the radiation dose in radiology since they produce visible light which increases the efficiency of the film. In addition, secondary X-rays arise due to the photoelectric effect, elastic (Rayleigh) and inelastic (Compton) scattering

Imaging plates for use with synchrotron radiation

International Nuclear Information System (INIS)

Amemiya, Yoshiyuki

1995-01-01

This review summarizes the principles and performance characteristics of the imaging-plate (IP) X-ray area detector, which is based on the photo-stimulable phosphor BaF(Br,I):Eu 2+ , together with some of its applications at the Photon Factory. The photo-stimulable phosphor can temporarily store an X-ray image. The stored image is reat out by measuring the intensity of luminescence, which is stimulated by an He-Ne laser beam scanning the phosphor surface. The IP has a spatial resolution of 170 μm (FWHM) with a pixel size of 100 x 100 μm and area sizes ranging from 127 x 127 to 201 x 400 mm 2 . The dynamic range is over 1:10 5 . The detective quantum efficiency, which is a function of exposure level, is more than 80% for 8-20 keV X-rays at medium exposure levels. The background noise level is equivalent to less than 3 X-ray photons/pixel of 8 keV. The precision in intensity measurement is 0.5-1% at best. These performance characteristics of the IP depend largely on the performance of the IP readout system. Two applications of the IP to time-resolved measurements are discussed: one is based on a cinema method which achieves a 0.3 s time resolution for 40 exposures of size 127 x 127 mm 2 , and the other uses the IP as a linear detector of length 200 mm with a 23 μs time resolution for a time period of 45 ms, based on the steak-camera method. (au) (17 refs.)

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.

Nanoparticles generated by laser in liquids as contrast medium and radiotherapy intensifiers

Science.gov (United States)

Restuccia, Nancy; Torrisi, Lorenzo

2018-01-01

The synthesis of Au and Ag nanoparticles (NP) though laser ablation in liquids as a function the laser parameters is presented. Spherical NPs with diameter distribution within 1 and 100 nm were prepared by laser ablation in water. The nanoparticles characterization was performed using optical spectroscopy and electronic microscopy (SEM and TEM) measurements. Studies of the possible use of metallic nanoparticles as intensifier of diagnostics imaging contrast medium and absorbing dose from ionizing radiations in traditional radiotherapy and protontherapy are presented. Examples of in vitro (in tissue equivalent materials) and in vivo (in mice), were conducted thank to simulation programs permitting to evaluate the enhancement of efficiency in imaging and therapy as a function of the NPs concentrations and irradiation conditions.

Nanoparticles generated by laser in liquids as contrast medium and radiotherapy intensifiers

Directory of Open Access Journals (Sweden)

Restuccia Nancy

2018-01-01

Full Text Available The synthesis of Au and Ag nanoparticles (NP though laser ablation in liquids as a function the laser parameters is presented. Spherical NPs with diameter distribution within 1 and 100 nm were prepared by laser ablation in water. The nanoparticles characterization was performed using optical spectroscopy and electronic microscopy (SEM and TEM measurements. Studies of the possible use of metallic nanoparticles as intensifier of diagnostics imaging contrast medium and absorbing dose from ionizing radiations in traditional radiotherapy and protontherapy are presented. Examples of in vitro (in tissue equivalent materials and in vivo (in mice, were conducted thank to simulation programs permitting to evaluate the enhancement of efficiency in imaging and therapy as a function of the NPs concentrations and irradiation conditions.

Study of x-ray CCD image sensor and application

Science.gov (United States)

Wang, Shuyun; Li, Tianze

2008-12-01

In this paper, we expounded the composing, specialty, parameter, its working process, key techniques and methods for charge coupled devices (CCD) twice value treatment. Disposal process for CCD video signal quantification was expatiated; X-ray image intensifier's constitutes, function of constitutes, coupling technique of X-ray image intensifier and CCD were analyzed. We analyzed two effective methods to reduce the harm to human beings when X-ray was used in the medical image. One was to reduce X-ray's radiation and adopt to intensify the image penetrated by X-ray to gain the same effect. The other was to use the image sensor to transfer the images to the safe area for observation. On this base, a new method was presented that CCD image sensor and X-ray image intensifier were combined organically. A practical medical X-ray photo electricity system was designed which can be used in the records and time of the human's penetrating images. The system was mainly made up with the medical X-ray, X-ray image intensifier, CCD vidicon with high resolution, image processor, display and so on. Its characteristics are: change the invisible X-ray into the visible light image; output the vivid images; short image recording time etc. At the same time we analyzed the main aspects which affect the system's resolution. Medical photo electricity system using X-ray image sensor can reduce the X-ray harm to human sharply when it is used in the medical diagnoses. At last we analyzed and looked forward the system's application in medical engineering and the related fields.

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

OpenAIRE

Kopp, Heidrun; Hindle, David; Klaeschen, Dirk; Oncken, O.; 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 décollement. Western Java, however, differs markedly from margins such as Nankai or Barbados...

Digital vascular imaging

International Nuclear Information System (INIS)

Ludwig, J.W.; Engels, B.C.H.

1981-01-01

Digitalizing videosignals from an image intensifying TV-chain, followed by subtraction, contrast intensifying, and reformation to analogous signal deliver angiography pictures of high quality after intravenous injection of the contrast medium. As the examination is only little invasive it can be carried out on outdoor patients or in the polyclinics. The possibilities of the digital vessel imagination (DVI) are shown at vessel images of different parts of the body; a 36 cm image intensifyer which can be switched to 3 different sorts of operation and has a plumbicon-TV recording tube is used as receiver. (orig.) [de

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.

Spirit Begins Drive Around Home Plate

Science.gov (United States)

2009-01-01

The hazard avoidance camera on the front of NASA's Mars Exploration Rover Spirit took this image after a drive by Spirit on the 1,829th Martian day, or sol, of Spirit's mission on the surface of Mars (Feb. 24, 2009). On Sol 1829, Spirit drove 6.29 meters (21 feet) northwestward, away from the northern edge of the low plateau called 'Home Plate.' The track dug by the dragged right-front wheel as the rover drove backward is visible in this image, receding toward the southeast. Rock layers of the northern slope of Home Plate are visible in the upper right portion of the image. In sols prior to 1829, the rover team had been trying to maneuver Spirit to climb onto the northern edge of Home Plate, ready to drive southward across the top of the plateau toward science destinations south of Home Plate. The Sol 1829 drive was the first move of a revised strategy to circle at least partway around Home Plate on the trek toward the sites south of the plateau.

Computer graphics of SEM images facilitate recognition of chromosome position in isolated human metaphase plates.

Science.gov (United States)

Hodge, L D; Barrett, J M; Welter, D A

1995-04-01

There is general agreement that at the time of mitosis chromosomes occupy precise positions and that these positions likely affect subsequent nuclear function in interphase. However, before such ideas can be investigated in human cells, it is necessary to determine first the precise position of each chromosome with regard to its neighbors. It has occurred to us that stereo images, produced by scanning electron microscopy, of isolated metaphase plates could form the basis whereby these positions could be ascertained. In this paper we describe a computer graphic technique that permits us to keep track of individual chromosomes in a metaphase plate and to compare chromosome positions in different metaphase plates. Moreover, the computer graphics provide permanent, easily manipulated, rapid recall of stored chromosome profiles. These advantages are demonstrated by a comparison of the relative position of group A-specific and groups D- and G-specific chromosomes to the full complement of chromosomes in metaphase plates isolated from a nearly triploid human-derived cell (HeLa S3) to a hypo-diploid human fetal lung cell.

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. Copyright © 2013 Elsevier B.V. All rights reserved.

High-speed imaging of blood splatter patterns

Energy Technology Data Exchange (ETDEWEB)

McDonald, T.E.; Albright, K.A.; King, N.S.P.; Yates, G.J. (Los Alamos National Lab., NM (United States)); Levine, G.F. (California Dept. of Justice, Sacramento, CA (United States). Bureau of Forensic Services)

1993-01-01

The interpretation of blood splatter patterns is an important element in reconstructing the events and circumstances of an accident or crime scene. Unfortunately, the interpretation of patterns and stains formed by blood droplets is not necessarily intuitive and study and analysis are required to arrive at a correct conclusion. A very useful tool in the study of blood splatter patterns is high-speed photography. Scientists at the Los Alamos National Laboratory, Department of Energy (DOE), and Bureau of Forensic Services, State of California, have assembled a high-speed imaging system designed to image blood splatter patterns. The camera employs technology developed by Los Alamos for the underground nuclear testing program and has also been used in a military mine detection program. The camera uses a solid-state CCD sensor operating at approximately 650 frames per second (75 MPixels per second) with a microchannel plate image intensifier that can provide shuttering as short as 5 ns. The images are captured with a laboratory high-speed digitizer and transferred to an IBM compatible PC for display and hard copy output for analysis. The imaging system is described in this paper.

High-speed imaging of blood splatter patterns

Energy Technology Data Exchange (ETDEWEB)

McDonald, T.E.; Albright, K.A.; King, N.S.P.; Yates, G.J. [Los Alamos National Lab., NM (United States); Levine, G.F. [California Dept. of Justice, Sacramento, CA (United States). Bureau of Forensic Services

1993-05-01

The interpretation of blood splatter patterns is an important element in reconstructing the events and circumstances of an accident or crime scene. Unfortunately, the interpretation of patterns and stains formed by blood droplets is not necessarily intuitive and study and analysis are required to arrive at a correct conclusion. A very useful tool in the study of blood splatter patterns is high-speed photography. Scientists at the Los Alamos National Laboratory, Department of Energy (DOE), and Bureau of Forensic Services, State of California, have assembled a high-speed imaging system designed to image blood splatter patterns. The camera employs technology developed by Los Alamos for the underground nuclear testing program and has also been used in a military mine detection program. The camera uses a solid-state CCD sensor operating at approximately 650 frames per second (75 MPixels per second) with a microchannel plate image intensifier that can provide shuttering as short as 5 ns. The images are captured with a laboratory high-speed digitizer and transferred to an IBM compatible PC for display and hard copy output for analysis. The imaging system is described in this paper.

Quantitative luminescence imaging system

Science.gov (United States)

Erwin, David N.; Kiel, Johnathan L.; Batishko, Charles R.; Stahl, Kurt A.

1990-01-01

The QLIS images and quantifies low-level chemiluminescent reactions in an electromagnetic field. It is capable of real time nonperturbing measurement and simultaneous recording of many biochemical and chemical reactions such as luminescent immunoassays or enzyme assays. The system comprises image transfer optics, a low-light level digitizing camera with image intensifying microchannel plates, an image process or, and a control computer. The image transfer optics may be a fiber image guide with a bend, or a microscope, to take the light outside of the RF field. Output of the camera is transformed into a localized rate of cumulative digitalized data or enhanced video display or hard-copy images. The system may be used as a luminescent microdosimetry device for radiofrequency or microwave radiation, as a thermal dosimeter, or in the dosimetry of ultra-sound (sonoluminescence) or ionizing radiation. It provides a near-real-time system capable of measuring the extremely low light levels from luminescent reactions in electromagnetic fields in the areas of chemiluminescence assays and thermal microdosimetry, and is capable of near-real-time imaging of the sample to allow spatial distribution analysis of the reaction. It can be used to instrument three distinctly different irradiation configurations, comprising (1) RF waveguide irradiation of a small Petri-dish-shaped sample cell, (2) RF irradiation of samples in a microscope for the microscopie imaging and measurement, and (3) RF irradiation of small to human body-sized samples in an anechoic chamber.

Optical image encryption using fresnel zone plate mask based on fast walsh hadamard transform

Science.gov (United States)

Khurana, Mehak; Singh, Hukum

2018-05-01

A new symmetric encryption technique using Fresnel Zone Plate (FZP) based on Fast Walsh Hadamard Transform (FWHT) is proposed for security enhancement. In this technique, bits of plain image is randomized by shuffling the bits randomly. The obtained scrambled image is then masked with FZP using symmetric encryption in FWHT domain to obtain final encrypted image. FWHT has been used in the cryptosystem so as to protect image data from the quantization error and for reconstructing the image perfectly. The FZP used in proposed scheme increases the key space and makes it robust to many traditional attacks. The effectiveness and robustness of the proposed cryptosystem has been analyzed on the basis of various parameters by simulating on MATLAB 8.1.0 (R2012b). The experimental results are provided to highlight suitability of the proposed cryptosystem and prove that the system is secure.

Less invasive plate osteosynthesis in humeral shaft fractures.

Science.gov (United States)

Apivatthakakul, Theerachai; Phornphutkul, Chanakarn; Laohapoonrungsee, Anupong; Sirirungruangsarn, Yuddhasert

2009-12-01

Stable internal fixation of the humeral shaft by less invasive percutaneous plate insertion using two separate (proximal and distal) incisions, indirect reduction by closed manipulation and fixation to preserve the soft tissue and blood supply at the fracture zone. Early mobilization of the shoulder and elbow to ensure a good functional outcome. Humeral shaft fractures (classified according to AO classification as: 12-A, B, C). Humeral shaft fractures extending to the proximal or distal shaft, small or deformed medullary canal or open growth plate. Humeral shaft fractures with primary radial nerve palsy. Proximal humeral shaft fractures extending to the humeral head. Distal humeral fractures extending to the elbow joint. Two incisions proximal and distal to the fracture zone are used. A 3-cm proximal incision lies between the lateral border of the proximal part of the biceps and the medial border of the deltoid. Distally, a 3-cm incision is made along the lateral border of the biceps. The interval between biceps and brachialis is identified. The biceps is retracted medially to expose the musculocutaneous nerve. The brachialis muscle has dual innervation, the medial half being innervated by the musculocutaneous nerve and the lateral half by the radial nerve. The brachialis is split longitudinally at its midline. The musculocutaneous nerve is retracted along with the medial half of the brachialis, while the lateral half of the brachialis serves as a cushion to protect the radial nerve. A deep subbrachial tunnel is created from the distal to the proximal incision. The selected plate is tied with a suture to a hole at the tip of the tunneling instrument for pulling the plate back along the prepared track. The plate is aligned in the correct position on the anterior surface of the humerus. Traction is applied and the fracture reduced to restore alignment by image intensifier, followed by plate fixation with at least two bicortical locking screws or three bicortical

Gain stabilized microchannel plates and a treatment method for microchannel plates

International Nuclear Information System (INIS)

1979-01-01

Microchannel plates having increased gain and significantly improved aging characteristics are provided by forming a thin film of a cesium compound on the channel walls. In an exemplary embodiment, a suface film of cesium hydroxide is applied to the interior wall surfaces of an MCP by saturating the plate with a solution of the compound, then allowing the solvent to evaporate. The cesium hydroxide residue on the walls subsequently is converted to cesium oxide by a high temperature bake. Microchannel plates are used in image amplifiers, radiation detectors and such like equipment. (Auth.)

Study for a novel tomography technique using an imaging plate

CERN Document Server

Kobayashi, H; Matsubayashi, M

1999-01-01

A sinogram is directly recorded onto an imaging plate for neutron tomography, which has excellent capability to detect neutrons. A sinogram-recording-system and outline of the data processing are explained briefly. A tomogram of a test object is reconstructed and shown as the preliminary result. The linearity of CT values was experimentally confirmed up to 1.6 cm sup - sup 1 of effective total macroscopic cross section, but about 10% lower CT value was observed at 2.7 cm sup - sup 1. The linearity limitation and statistical character of CT values are discussed with regard to the dynamic range of the system as well as the effect of background components.

Evaluation of the Effect of Light and Scanning Time Delay on The Image Quality of Intra Oral Photostimulable Phosphor Plates.

Science.gov (United States)

Eskandarloo, Amir; Yousefi, Arman; Soheili, Setareh; Ghazikhanloo, Karim; Amini, Payam; Mohammadpoor, Haniyeh

2017-01-01

Nowadays, digital radiography is widely used in dental practice. One of the most common types is Photo Stimulated Phosphor Plate (PSP). The aims of this experimental study were to evaluate the impacts of different combinations of storage conditions and varying delays in reading of digital images captured using PSPs. Standardized images of a step wedges were obtained using PSPs from the Digora digital systems. Plates were exposed and immediately scanned to produce the baseline gold standard. The plates were re-exposed and stored in four different storage conditions: white light, yellow light, natural light environment and dark room, then scanned after 10 and 30 minutes and 4 and 8 hours. Objective analysis was conducted by density measurements and the data were analyzed statistically using GEE test. Subjective analysis was performed by two oral and maxillofacial radiologists and the results were analyzed using McNemar's test. The results from GEE analysis show that in the natural light environment, the densities in 10 minutes did not differ from the baseline. The mean densities decreased significantly during the time in all environments. The mean densities in step 2 for the dark room environment decreased with a slighter slope in comparison to yellow environment significantly. PSP images showed significant decrease in the density in plates scanned for 10 minutes or longer after exposure which may not be detected clinically. The yellow light environment had a different impact on the quality of PSP images. The spatial resolution did not change significantly with time.

Energy response of imaging plates to radiation beams from standard beta sources, ortho-voltage and cobalt-60 units and linear accelerators

Science.gov (United States)

Gonzalez, Albin Leonel

The response to different types of radiation beams of commercial imaging plates used for diagnostic computed radiography has been investigated in this work. Imaging plates are designed with a phosphor layer which after been irradiated; information is stored in the form of photostimulable luminescence (PSL) centers. Initial measurements of the dose distribution of a radioactive stent with the imaging plates showed similar results to those with radiochromic films, but with much shorter exposure time due to their higher sensitivity. In order to investigate further their response, the imaging plates were irradiated with calibrated beams from: standard beta sources, orthovoltage and Co-60 units and therapy linear accelerator. Initially it was found that the energy to create the storage centers (generation efficiency) when irradiated with the three standard beta sources (225 keV to 2.28 MeV) was the same. For the rest of the calibrated beams an in house reader system was built in order to perform the bleaching of the plates with a He-Ne laser (632.8 nm) and to measure the absolute number of the emitted PSL photons (storage centers produced). Bleaching curves were then obtained for different exposure times for each beam. From the graph of the calculated area under the bleaching curves (total number of storage center) versus the absorbed dose to the phosphor layer it was possible to calculate the energy to create the storage centers (generation efficiency) for photon and electron beams. The dose to the phosphor layer was calculated in the case of the electron beams following a scaling procedure, while in the case of the photon beams Monte Carlo simulations were performed. For the photons beams the measurement of the generation efficiency energy of 126 +/- 8% eV per PSL storage center, coincide with measurements using a different approach (˜148 eV) by previous investigators. The generation efficiency for the electron beam was 807 +/- 3% eV, no reference was found in the

Sigmoid plate dehiscence: Congenital or acquired condition?

Energy Technology Data Exchange (ETDEWEB)

Liu, Zhaohui, E-mail: lzhtrhos@163.com [Capital Medical University, Beijing Tongren Hospital, No 1 Dong Jiao Min Street, Dongcheng District, Beijing 100730 (China); Li, Jing, E-mail: lijingxbh@yahoo.com.cn [Capital Medical University, Beijing Tongren Hospital, No 1 Dong Jiao Min Street, Dongcheng District, Beijing 100730 (China); Zhao, Pengfei, E-mail: zhaopengf05@163.com [Capital Medical University, Beijing Friendship Hospital, No 95 Yongan Road, Xicheng District, Beijing 100050 (China); Lv, Han, E-mail: chrislvhan@126.com [Capital Medical University, Beijing Friendship Hospital, No 95 Yongan Road, Xicheng District, Beijing 100050 (China); Dong, Cheng, E-mail: derc007@sina.com [Capital Medical University, Beijing Friendship Hospital, No 95 Yongan Road, Xicheng District, Beijing 100050 (China); Liu, Wenjuan, E-mail: wenjuanliu@163.com [Jining No. 1 People' s Hospital, No. 6 Health Street, Jining 272100 (China); Wang, Zhenchang, E-mail: cjr.wzhch@vip.163.com [Capital Medical University, Beijing Friendship Hospital, No 95 Yongan Road, Xicheng District, Beijing 100050 (China)

2015-05-15

Highlights: • CT with multiplanar reformations can accurately display the sigmoid platet dehiscence. • The prevalence of sigmoid plate dehiscence was no significant difference among different age groups. • The size of sigmoid plate bony defects were not statistically different among different age groups. • The sigmoid plate dehiscence is more commonly a congenital than an acquired condition. - Abstract: Background and purpose: The imaging features of sigmoid plate dehiscence-induced pulsatile tinnitus have been presented. The origin of the sigmoid plate dehiscence, however, remains unclear. Our aim was to assess the prevalence and extent of sigmoid plate dehiscence on computed tomography (CT) images in multiple age groups to determine whether this condition is more likely to be congenital or acquired. Materials and methods: We retrospectively reviewed contrast-enhanced CT images of sigmoid plates of temporal bones in 504 patients. Each temporal bone was characterized as normal or dehiscent. Patients were then subcategorized into four age groups, and the prevalence and extent of dehiscent sigmoid plates in each group were calculated and compared. Results: Overall, 80 patients had sigmoid plate dehiscence, nine of whom had it bilaterally. In successively older age groups, the prevalences of sigmoid plate dehiscence were 18.9%, 20.1%, 14.5%, and 12.7%, respectively. Respective average anteroposterior bony defect diameters were 3.7 ± 1.7, 3.0 ± 1.3, 3.1 ± 1.5, and 3.0 ± 1.1 mm. Respective average vertical bony defect diameters were 3.6 ± 2.3, 2.6 ± 1.2, 3.2 ± 1.5, and 3.0 ± 1.7 mm. The prevalence and extent of sigmoid plate dehiscence were not statistically different among the four age groups. Conclusions: The similar radiologic prevalence and extent of dehiscent sigmoid plates among the age groups suggest that the dehiscence is more commonly a congenital than an acquired condition.

Sigmoid plate dehiscence: Congenital or acquired condition?

International Nuclear Information System (INIS)

Liu, Zhaohui; Li, Jing; Zhao, Pengfei; Lv, Han; Dong, Cheng; Liu, Wenjuan; Wang, Zhenchang

2015-01-01

Highlights: • CT with multiplanar reformations can accurately display the sigmoid platet dehiscence. • The prevalence of sigmoid plate dehiscence was no significant difference among different age groups. • The size of sigmoid plate bony defects were not statistically different among different age groups. • The sigmoid plate dehiscence is more commonly a congenital than an acquired condition. - Abstract: Background and purpose: The imaging features of sigmoid plate dehiscence-induced pulsatile tinnitus have been presented. The origin of the sigmoid plate dehiscence, however, remains unclear. Our aim was to assess the prevalence and extent of sigmoid plate dehiscence on computed tomography (CT) images in multiple age groups to determine whether this condition is more likely to be congenital or acquired. Materials and methods: We retrospectively reviewed contrast-enhanced CT images of sigmoid plates of temporal bones in 504 patients. Each temporal bone was characterized as normal or dehiscent. Patients were then subcategorized into four age groups, and the prevalence and extent of dehiscent sigmoid plates in each group were calculated and compared. Results: Overall, 80 patients had sigmoid plate dehiscence, nine of whom had it bilaterally. In successively older age groups, the prevalences of sigmoid plate dehiscence were 18.9%, 20.1%, 14.5%, and 12.7%, respectively. Respective average anteroposterior bony defect diameters were 3.7 ± 1.7, 3.0 ± 1.3, 3.1 ± 1.5, and 3.0 ± 1.1 mm. Respective average vertical bony defect diameters were 3.6 ± 2.3, 2.6 ± 1.2, 3.2 ± 1.5, and 3.0 ± 1.7 mm. The prevalence and extent of sigmoid plate dehiscence were not statistically different among the four age groups. Conclusions: The similar radiologic prevalence and extent of dehiscent sigmoid plates among the age groups suggest that the dehiscence is more commonly a congenital than an acquired condition

Pengaruh Jenis Lembar Penguat (Intensifying Screen) Terhadap Densitas Radiografi

OpenAIRE

Nasrullah

2007-01-01

good ABSTRACT As done research on the influence of type to the density radiography with the objective to define radiography value third-density intensifying screen brand green emitting variation factors exposure and Focus Film Distance is different. Influence of type of intensifying screen to the density radiography is obtained through measurements of the value of radiography density using the densitometer with object stepwedge. The results of this research show that the average dens...

Modeling susceptibility difference artifacts produced by metallic implants in magnetic resonance imaging with point-based thin-plate spline image registration.

Science.gov (United States)

Pauchard, Y; Smith, M; Mintchev, M

2004-01-01

Magnetic resonance imaging (MRI) suffers from geometric distortions arising from various sources. One such source are the non-linearities associated with the presence of metallic implants, which can profoundly distort the obtained images. These non-linearities result in pixel shifts and intensity changes in the vicinity of the implant, often precluding any meaningful assessment of the entire image. This paper presents a method for correcting these distortions based on non-rigid image registration techniques. Two images from a modelled three-dimensional (3D) grid phantom were subjected to point-based thin-plate spline registration. The reference image (without distortions) was obtained from a grid model including a spherical implant, and the corresponding test image containing the distortions was obtained using previously reported technique for spatial modelling of magnetic susceptibility artifacts. After identifying the nonrecoverable area in the distorted image, the calculated spline model was able to quantitatively account for the distortions, thus facilitating their compensation. Upon the completion of the compensation procedure, the non-recoverable area was removed from the reference image and the latter was compared to the compensated image. Quantitative assessment of the goodness of the proposed compensation technique is presented.

Automatic Number Plate Recognition System for IPhone Devices

Directory of Open Access Journals (Sweden)

Călin Enăchescu

2013-06-01

Full Text Available This paper presents a system for automatic number plate recognition, implemented for devices running the iOS operating system. The methods used for number plate recognition are based on existing methods, but optimized for devices with low hardware resources. To solve the task of automatic number plate recognition we have divided it into the following subtasks: image acquisition, localization of the number plate position on the image and character detection. The first subtask is performed by the camera of an iPhone, the second one is done using image pre-processing methods and template matching. For the character recognition we are using a feed-forward artificial neural network. Each of these methods is presented along with its results.

Electroless plating of Cu-Ni-P alloy on PET fabrics and effect of plating parameters on the properties of conductive fabrics

International Nuclear Information System (INIS)

Gan Xueping; Wu Yating; Liu Lei; Shen Bin; Hu Wenbin

2008-01-01

Electroless plating of Cu-Ni-P alloy on polyethylene terephthalate (PET) fabrics and effect of plating parameters on the properties of alloy-coated fabrics were investigated. The deposition rate increased with the increase of temperature, pH and nickel ion concentration. The addition of K 4 Fe(CN) 6 to the solution could reduce the deposition rate and make the deposits become more compact. The color of the deposits also had a corresponding improvement, changing from dark-brown to copper-bright with the addition of K 4 Fe(CN) 6 to the plating solution. The deposits have an intensified copper (1 1 1) plane orientation with the addition of K 4 Fe(CN) 6 to the plating bath. The surface electrical resistance of alloy-coated fabrics increased with increase of nickel ions concentration in the solution. The addition of K 4 Fe(CN) 6 to the solution reduced significantly the surface resistance of alloy-coated fabrics. The conductive fabrics with high shielding effectiveness could be prepared at the optimum condition with 0.0038 M nickel ions and 2 ppm K 4 Fe(CN) 6 . As the deposit weight on the fabric was 40 g/m 2 , the shielding effectiveness of alloy-coated fabrics was more than 85 dB at frequency ranging from 100 MHz to 20 GHz

Coupled oscillations of flow along a perforated plate

International Nuclear Information System (INIS)

Celik, E.; Rockwell, D.

2004-01-01

Turbulent shear flow past a perforated plate bounded by a closed cavity can give rise to highly coherent oscillations, which have a wavelength of the order of the plate length. The present investigation focuses on the coupling between unsteady events on either side of the plate when the oscillations are self-sustaining. A cinema technique of high-image-density particle image velocimetry, which provides a space-time representation of the unsteadiness at a large number of locations over entire planes, is employed to characterize the distinctively different patterns of flow structure on the back (low-speed) side of the plate relative to those on the front (high-speed) side. Global cross-spectral analysis leads to patterns of spectral peaks and phase variations, along and across the plate. This approach, along with complementary types of image evaluation, delineates the physics of the oscillations, which include downstream propagating disturbances along either side of the plate and a coherent region of unsteadiness at its trailing-edge. On the backside of the plate, a sequence of upstream-oriented, pulsatile jets are formed, and the time-averaged flow pattern is a counterflow wall jet

Paper microzone plates.

Science.gov (United States)

Carrilho, Emanuel; Phillips, Scott T; Vella, Sarah J; Martinez, Andres W; Whitesides, George M

2009-08-01

This paper describes 96- and 384-microzone plates fabricated in paper as alternatives to conventional multiwell plates fabricated in molded polymers. Paper-based plates are functionally related to plastic well plates, but they offer new capabilities. For example, paper-microzone plates are thin (approximately 180 microm), require small volumes of sample (5 microL per zone), and can be manufactured from inexpensive materials ($0.05 per plate). The paper-based plates are fabricated by patterning sheets of paper, using photolithography, into hydrophilic zones surrounded by hydrophobic polymeric barriers. This photolithography used an inexpensive formulation photoresist that allows rapid (approximately 15 min) prototyping of paper-based plates. These plates are compatible with conventional microplate readers for quantitative absorbance and fluorescence measurements. The limit of detection per zone loaded for fluorescence was 125 fmol for fluorescein isothiocyanate-labeled bovine serum albumin, and this level corresponds to 0.02 the quantity of analyte per well used to achieve comparable signal-to-noise in a 96-well plastic plate (using a solution of 25 nM labeled protein). The limits of detection for absorbance on paper was approximately 50 pmol per zone for both Coomassie Brilliant Blue and Amaranth dyes; these values were 0.4 that required for the plastic plate. Demonstration of quantitative colorimetric correlations using a scanner or camera to image the zones and to measure the intensity of color, makes it possible to conduct assays without a microplate reader.

Micro calcification evaluation using CR plates in computerized mammography

International Nuclear Information System (INIS)

Bustos F, M.; Prata M, A.

2017-10-01

Cancer is one of the leading causes of mortality in the world. In 2012, about 14 million new cases were registered, of which 1.6 million are breast cancer, according to the World Health Organization. The National Cancer Institute of Brazil estimated 57 thousand new cases of breast cancer by 2016. Mammography is the imaging technique most used worldwide for the early diagnosis of breast cancer. Computed radiography (CR) plates are used for digital radiography, and are widely used to obtain digital mammograms. This work aims to evaluate te response of CR plates to the variation of exposure in mammography equipment. Three CR plates for mammography of different models were used for the study. X-ray beams were selected to perform successive exposures of CR plates by varying the exposure time. These exposures were performed to obtain raw images that were subsequently analyzed using ImageJ software, from which the value of intensity recorded in the central region of each image was obtained, correlating it with the exposure time. From these data the necessary correlations were made to determine the exposure time for which the CR plate begins to saturate, observing that the saturation occurs first for the highest value of the applied voltage. Finally, successive exposures of the CR plate were made using the compressed breast simulator made of acrylic plates and containing microcalcifications of different sizes to determine the qualitative resolution of CR plates, observing that only microcalcifications above 177 μm are visible in the image. The knowledge of saturation characteristics and resolution of the CR plate allows the selection of more adequate parameters to work without approaching the saturation region. (Author)

Micro calcification evaluation using CR plates in computerized mammography

Energy Technology Data Exchange (ETDEWEB)

Bustos F, M.; Prata M, A., E-mail: mabelita.bfm@gmail.com [Federal University of Minas Gerais, School of Engineering, Department of Nuclear Engineering, Av. Antonio Carlos CEP 131270-901 Belo Horizonte, Minas Gerais (Brazil)

2017-10-15

Cancer is one of the leading causes of mortality in the world. In 2012, about 14 million new cases were registered, of which 1.6 million are breast cancer, according to the World Health Organization. The National Cancer Institute of Brazil estimated 57 thousand new cases of breast cancer by 2016. Mammography is the imaging technique most used worldwide for the early diagnosis of breast cancer. Computed radiography (CR) plates are used for digital radiography, and are widely used to obtain digital mammograms. This work aims to evaluate te response of CR plates to the variation of exposure in mammography equipment. Three CR plates for mammography of different models were used for the study. X-ray beams were selected to perform successive exposures of CR plates by varying the exposure time. These exposures were performed to obtain raw images that were subsequently analyzed using ImageJ software, from which the value of intensity recorded in the central region of each image was obtained, correlating it with the exposure time. From these data the necessary correlations were made to determine the exposure time for which the CR plate begins to saturate, observing that the saturation occurs first for the highest value of the applied voltage. Finally, successive exposures of the CR plate were made using the compressed breast simulator made of acrylic plates and containing microcalcifications of different sizes to determine the qualitative resolution of CR plates, observing that only microcalcifications above 177 μm are visible in the image. The knowledge of saturation characteristics and resolution of the CR plate allows the selection of more adequate parameters to work without approaching the saturation region. (Author)

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

International Nuclear Information System (INIS)

Ohuchi, H.; Yamadera, A.

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 equation for correcting the effects of the differences in the image readers was attempted

Digital image intensifier radiography: first experiences with the DSI (Digital Spot Imaging)

International Nuclear Information System (INIS)

Rueckforth, J.; Wein, B.; Stargardt, A.; Guenther, R.W.

1995-01-01

We performed a comparative study of digitally and conventionally acquired images in gastrointestinal examinations. Radiation dose and spatial resolution were determined in a water phantom. In 676 examinations with either conventional or digital imaging (system: Diagnost 76, DSI) the number of images and the duration of the fluoroscopy time were compared. 101 examinations with digital as well as conventional documentation were evaluated by using 5 criteria describing the diagnostic performance. The entrance dose of the DSI is 12% to 36% of the film/screen system and the spatial resolution of the DSI may be better than that of a film/screen system with a speed of 200. The fluoroscopy time shows no significant difference between DSI and the film/screen technique. In 2 of 4 examination modes significantly more images were produced by the DSI. With exception of the criterion of edge sharpness, DSI yields a significantly inferior assessment compared with the film/screen technique. (orig./MG) [de

Research on range-gated laser active imaging seeker

Science.gov (United States)

You, Mu; Wang, PengHui; Tan, DongJie

2013-09-01

Compared with other imaging methods such as millimeter wave imaging, infrared imaging and visible light imaging, laser imaging provides both a 2-D array of reflected intensity data as well as 2-D array of range data, which is the most important data for use in autonomous target acquisition .In terms of application, it can be widely used in military fields such as radar, guidance and fuse. In this paper, we present a laser active imaging seeker system based on range-gated laser transmitter and sensor technology .The seeker system presented here consist of two important part, one is laser image system, which uses a negative lens to diverge the light from a pulse laser to flood illuminate a target, return light is collected by a camera lens, each laser pulse triggers the camera delay and shutter. The other is stabilization gimbals, which is designed to be a rotatable structure both in azimuth and elevation angles. The laser image system consists of transmitter and receiver. The transmitter is based on diode pumped solid-state lasers that are passively Q-switched at 532nm wavelength. A visible wavelength was chosen because the receiver uses a Gen III image intensifier tube with a spectral sensitivity limited to wavelengths less than 900nm.The receiver is image intensifier tube's micro channel plate coupled into high sensitivity charge coupled device camera. The image has been taken at range over one kilometer and can be taken at much longer range in better weather. Image frame frequency can be changed according to requirement of guidance with modifiable range gate, The instantaneous field of views of the system was found to be 2×2 deg. Since completion of system integration, the seeker system has gone through a series of tests both in the lab and in the outdoor field. Two different kinds of buildings have been chosen as target, which is located at range from 200m up to 1000m.To simulate dynamic process of range change between missile and target, the seeker system has

Illumination estimation via thin-plate spline interpolation.

Science.gov (United States)

Shi, Lilong; Xiong, Weihua; Funt, Brian

2011-05-01

Thin-plate spline interpolation is used to interpolate the chromaticity of the color of the incident scene illumination across a training set of images. Given the image of a scene under unknown illumination, the chromaticity of the scene illumination can be found from the interpolated function. The resulting illumination-estimation method can be used to provide color constancy under changing illumination conditions and automatic white balancing for digital cameras. A thin-plate spline interpolates over a nonuniformly sampled input space, which in this case is a training set of image thumbnails and associated illumination chromaticities. To reduce the size of the training set, incremental k medians are applied. Tests on real images demonstrate that the thin-plate spline method can estimate the color of the incident illumination quite accurately, and the proposed training set pruning significantly decreases the computation.

Use of imaging plates at near saturation for high energy density particles

International Nuclear Information System (INIS)

Tanimoto, Tsuyoshi; Ohta, Kazuhide; Habara, Hideaki; Kodama, Ryousuke; Tanaka, Kazuo A.; Yabuuchi, Toshinori; Tampo, Motonobu; Zheng Jian

2008-01-01

Since an imaging plate (IP) is sensitive to electron, ion, and x rays, it can be used as a detector for laser plasma experiment using ultraintense laser. Moreover, an IP has the advantageous features such as high sensitivity, wide dynamic range, and high spatial resolution. Even though IP itself has a considerable wide dynamic range up to 10 5 , the IP data have appeared often saturated at an IP reading device. We propose a reading technique by inserting optical density filters so that an apparently saturated IP data can be saved.

Coherent x-ray diffraction imaging of paint pigment particles by scanning a phase plate modulator

International Nuclear Information System (INIS)

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

2011-01-01

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.

Improvement of visualization efficiency for the nondestructive inspection image of internal defects in plate type nuclear fuel

International Nuclear Information System (INIS)

Park, Seung Kyu; Park, Nak Kyu; Baik, Sung Hoon; Lee, Yoon Sang; Cheong, Yong Moo; Kang, Young June

2012-01-01

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

Study on radioactive fallout from Fukushima nuclear accident by plant samples using an imaging plate system

International Nuclear Information System (INIS)

Minowa, Haruka

2011-01-01

The radioactive fallout from the Fukushima nuclear accident was investigated by the radiation images of plant samples using an Imaging Plate System. Plant samples exposed by an imaging plate BASIII 2040 (Fujifilm, Japan) in overnight to one week, and radiation images were read by Typhoon FLA7000 (GE Healthcare Japan Corp.). Identifying and quantitative analysis of radionuclides were measured by Auto Well Gamma System ARC-380CL (Aloha Co. Ltd., Tokyo, Japan). In the cross-sectional images of the bamboo shoot, the radioactive material is shown in heterogeneous distribution, it was found that it concentrated on the tip of the edible portion, and thin skin. These radionuclides were identified as "1"3"7Cs, "1"3"4Cs, and "4"0K. "4"0K is a natural radionuclide, on the other hand "1"3"7Cs and "1"3"4Cs would be derived from the accident of the Fukushima Daiichi Nuclear Power Plant. A high concentration of "1"3"4Cs was shown at the distance of 150 mm from the base of the bamboo shoot by cross-sectional cutting into the width of about 1 mm. It was estimated about 1 kBq of "1"3"4Cs would be included in about 400 g (wet weight) of this one bamboo shoot in an edible part. Imaging data suggests that the contamination of radioactive cesium in this bamboo shoot was caused not by the extraneous attachment but by the absorption from roots. Because bamboo is gather water from extensive area, bamboo shoot concentrates the radioactive material contained in the rain even at low concentrations of radioactive materials in soil. (author)

X-ray intensifying screens

International Nuclear Information System (INIS)

Bossomaier, T.R.J.; Sangway, P.C.

1979-01-01

It is claimed that stabilization of X-ray intensifying screens against discolouration and hydrolysis of lanthanum or gadolinium oxyhalide phosphors can be achieved by incorporating into the phosphor/binder formulation a compound containing free epoxy groups. Suitable epoxy compounds include gamma glycidoxy trimethoxy silane and dimethyl di(m-glycidoxy methylphenyl) methane. The oxyhalide may be activated by Tb, Tm or Yb and may be mixed with other phosphors. Plasticisers and organo-tin stabilisers for the formulation are given. Many binders are specified, preferably these should not react with the free epoxy groups. (UK)

Automatic system for localization and recognition of vehicle plate numbers

OpenAIRE

Vázquez, N.; Nakano, M.; Pérez-Meana, H.

2003-01-01

This paper proposes a vehicle numbers plate identification system, which extracts the characters features of a plate from a captured image by a digital camera. Then identify the symbols of the number plate using a multilayer neural network. The proposed recognition system consists of two processes: The training process and the recognition process. During the training process, a database is created using 310 vehicular plate images. Then using this database a multilayer neural network is traine...

Picosecond x-ray streak cameras

Science.gov (United States)

Averin, V. I.; Bryukhnevich, Gennadii I.; Kolesov, G. V.; Lebedev, Vitaly B.; Miller, V. A.; Saulevich, S. V.; Shulika, A. N.

1991-04-01

The first multistage image converter with an X-ray photocathode (UMI-93 SR) was designed in VNIIOFI in 1974 [1]. The experiments carried out in IOFAN pointed out that X-ray electron-optical cameras using the tube provided temporal resolution up to 12 picoseconds [2]. The later work has developed into the creation of the separate streak and intensifying tubes. Thus, PV-003R tube has been built on base of UMI-93SR design, fibre optically connected to PMU-2V image intensifier carrying microchannel plate.

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.

Human water consumption intensifies hydrological drought worldwide

International Nuclear Information System (INIS)

Wada, Yoshihide; Van Beek, Ludovicus P H; Wanders, Niko; Bierkens, Marc F P

2013-01-01

Over the past 50 years, human water use has more than doubled and affected streamflow over various regions of the world. However, it remains unclear to what degree human water consumption intensifies hydrological drought (the occurrence of anomalously low streamflow). Here, we quantify over the period 1960–2010 the impact of human water consumption on the intensity and frequency of hydrological drought worldwide. The results show that human water consumption substantially reduced local and downstream streamflow over Europe, North America and Asia, and subsequently intensified the magnitude of hydrological droughts by 10–500%, occurring during nation- and continent-wide drought events. Also, human water consumption alone increased global drought frequency by 27 (±6)%. The intensification of drought frequency is most severe over Asia (35 ± 7%), but also substantial over North America (25 ± 6%) and Europe (20 ± 5%). Importantly, the severe drought conditions are driven primarily by human water consumption over many parts of these regions. Irrigation is responsible for the intensification of hydrological droughts over the western and central US, southern Europe and Asia, whereas the impact of industrial and households’ consumption on the intensification is considerably larger over the eastern US and western and central Europe. Our findings reveal that human water consumption is one of the more important mechanisms intensifying hydrological drought, and is likely to remain as a major factor affecting drought intensity and frequency in the coming decades. (letter)

Dynamic Characterizations of an 8-frame, Half-Strip, High-speed X-ray Microchannel Plate Imager

International Nuclear Information System (INIS)

Ken Moy; Ming Wu; Craig Kruschwitz; Aric Tibbits; Matt Griffin; Greg Rochau

2008-01-01

High-speed microchannel plate (MCP)-based imagers are critical detectors for x-ray diagnostics employed on Z-experiments at Sandia National Laboratories (SNL) to measure time-resolved x-ray spectra and to image dynamic hohlraums. A multiframe design using eight half strips in one imager permits recordings of radiation events in discrete temporal snapshots to yield a time-evolved movie. We present data using various facilities to characterize the performance of this design. These characterization studies include DC and pulsed-voltage biased measurements in both saturated and linear operational regimes using an intense, short-pulsed UV laser. Electrical probe measurements taken to characterize the shape of the HV pulse propagating across the strips help to corroborate the spatial gain dependence

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

International Nuclear Information System (INIS)

Kurebayashi, Y.; Sakurai, H.; Takahashi, Y.; Doshita, N.; Kikuchi, S.; Tokanai, F.; Horiuchi, K.; Tajima, Y.; Oe, T.; Sato, T.; Gunji, S.; Inui, E.; Kondo, K.; Iwata, N.; Sasaki, N.; Matsuzaki, H.; Kunieda, S.

2015-01-01

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 –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 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

Measurements of image characteristics of DSA installations

International Nuclear Information System (INIS)

Busch, H.P.; Strauss, L.G.; Freimarck, R.D.

1984-01-01

Measurements for quantifying the image characteristics were carried out on three DSA installations (DVI 1 - Philips, Angiotron - Siemens and DF 3000 - General Eletric). Contrast resolution was measured with a vessel phantom (General Electric) and spatial resolution with a lead grid. A further parameter was the dose entering the image intensifier. The Angiotron was used with an intensifier with 53 cm. diameter and the DF 3000 with temporal subtraction of the video images and the subtraction of dual energy images (hybrid technique). These measurements can be carried out quickly and easily and are a step towards standardisation of measurements of image characteristics of DSA installations. (orig.) [de

Panoramic dental radiography image intensification employing minification techniques

International Nuclear Information System (INIS)

Cushman, R.H.

1981-01-01

Panoramic dental x-ray machine wherein an x-ray source-camera assembly orbits a seated patient is described. A slot in the camera assembly collimates the x-rays which are continuously generated by the x-ray source, which x-rays are converted to light images of the patient's dental arch structure by only a single intensifying screen which remains stationary. This screen comprises about 1/40 the area of conventional intensifying screens and is made thicker for providing improved detection efficiency. A fiber optic minifying lens reduces the size of the image from the screen while proportionately increasing the light intensity of the image, thus making it possible to provide useable film images at reduced x-ray exposures due to non-linear film exposure versus optical density characteristics. The resultant minified, light-intensified image may now be recorded on 35 mm roll film, for example, as opposed to standard radiographic film of 5'' X 12'' size, or 12.70 cm X 30.48 cm

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.

Comparison of the new and the used imaging plates on computed radiography

International Nuclear Information System (INIS)

Ding Weihong; Zhang Weimin; Wang Jiawei

2008-01-01

Objective: To compare image quality and radiation dose of the new imaging plate (IP) with the used IP on computed radiography (CR), and to investigate the using principle in the two kinds of IP. Methods: The dark noise, uniformity and erasure thoroughness of the new and the used IP were measured respectively. Based on threshold contrast-detail detectability (TCCD) technique, the phantom TO, 16 photography was done at 75 kV, and with the two kinds of IP respectively. Three observers scored each image sequence using double blind method, calculated the threshold detection index (H T ). The volunteers were randomly divided into three groups: the knee joint group, the chest group and the lumbar group. Each group had 50 cases and checked with the same condition as the phantom. Three radiologists using double blind method evaluated the imaging quality of knee joint, chest and lumbar. Results: The physical characteristic indexes of the new and the used IP were similar to each other. Under the same condition, the detection ability of the new IP was better than that of the used one. When the dose of exposure was raised about 20%, the detection ability of the used IP was close to that of the new one. Conclusions: The dose of exposure can be raised to keep the same imaging quality with the increase times of IP used. The detection ability of IP can decrease with the same dose as before, and the image quality decreases too. (authors)

Registration of segmented histological images using thin plate splines and belief propagation

Science.gov (United States)

Kybic, Jan

2014-03-01

We register images based on their multiclass segmentations, for cases when correspondence of local features cannot be established. A discrete mutual information is used as a similarity criterion. It is evaluated at a sparse set of location on the interfaces between classes. A thin-plate spline regularization is approximated by pairwise interactions. The problem is cast into a discrete setting and solved efficiently by belief propagation. Further speedup and robustness is provided by a multiresolution framework. Preliminary experiments suggest that our method can provide similar registration quality to standard methods at a fraction of the computational cost.

High spatial resolution X-UV Fresnel zone plates imaging; Imagerie a haute resolution spatiale dans le domaine X-UV a l'aide de lentilles a zone de Fresnel

Energy Technology Data Exchange (ETDEWEB)

Pichet-Thomasset, M

1999-07-01

The goal of this work is to study the capabilities of imaging of Fresnel zone plates in the 1.5. and 2 keV X-ray range for the imaging of laser-produced plasmas. The diagnostic is composed of a Fresnel zone plate with good imaging capabilities and a multilayer mirror to select the spectral emission bandwidth of the plasma we want to study. This diagnostic was evaluated at the Centre d'Etudes de Limeil-Valenton experiments to study spatial resolution with this kind of X-ray source. The images we obtained showed that there is no geometric aberrations over an object field of several millimetre. Fresnen zone plates are often used for monochromatic biological objects imaging in the water window around 400 eV but they offer large prospects for laser produced plasma imaging. (author)

Digital Archive of the Astrograph Plates Stored at the Inasan Zvenigorod Observatory

Directory of Open Access Journals (Sweden)

Vereshchagin S. V.

2012-09-01

Full Text Available The plate collection of the Zvenigorod 40-cm Carl Zeiss astrograph, obtained in 1972-2003, contains direct photographs of star fields, comets, asteroids, Pluto, and Mars. The electronic library of images from photographic plates was created from scanning the astronomical negatives. We present information on programs scheduled at the telescope and the structure and maintenance of the plate stacks. We also list the plates with images of asteroids and comets. Access to all our plate lists is provided at the web sites of the Institute of Astronomy (INASAN and WFPDB. It is possible to select plates by the date of observation, by the coordinates of the sky area, by the object type. Preview images can be inspected.

Traditional x-ray imaging

International Nuclear Information System (INIS)

Hay, G.A.

1982-01-01

Methods of imaging x-rays, with particular reference to medicine, are reviewed. The history and nature of x-rays, their production and spectra, contrast, shapes and fine structure, image transducers, including fluorescent screens, radiography, fluoroscopy, and image intensifiers, image detection, perception and enhancement and clinical applications are considered. (U.K.)

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.

Are the Satellite-Observed Narrow, Streaky Chlorophyll Filaments Locally Intensified by the Submesoscale Processes?

Science.gov (United States)

2015-11-05

HIS I’OR’A CANCELS AND SUPERSEOFS Al l PRFV•OUS VERSIONS ARE THE SATELLITE-OBSERVED NARROW, STREAKY CHLOROPHYLL FILAMENTS LOCALLY INTENSIFIED BY...AUGUST 2003 cold, dense jeto C 17 16 15 14 13 122.4W 122W 122.4W 122W warm, anticyclonic eddy CHLOROPHYLL 122.4W 122W 122.4W 122W 122.4W 122W filament...122.4W 122W mg/m 3 10 4 2 1 0.4 0.2 Figure 1. MODIS-Aqua SST and Chlorophyll a images for August 2003. Black lines on MODIS SST and Chlorophyll a

Optimized image processing with modified preprocessing of image data sets of a transparent imaging plate by way of the lateral view of the cervical spine

International Nuclear Information System (INIS)

Reissberg, S.; Hoeschen, C.; Redlich, U.; Scherlach, C.; Preuss, H.; Kaestner, A.; Doehring, W.; Woischneck, D.; Schuetze, M.; Reichardt, K.; Firsching, R.

2002-01-01

Purpose: To improve the diagnostic quality of lateral radiographs of the cervical spine by pre-processing the image data sets produced by a transparent imaging plate with both-side reading and to evaluate any possible impact on minimizing the number of additional radiographs and supplementary investigations. Material and Methods: One hundred lateral digital radiographs of the cervical spine were processed with two different methods: processing of each data set using the system-imminent parameters and using the manual model. The difference between the two types of processing is the level of the latitude value. Hard copies of the processed images were judged by five radiologists and three neurosurgeons. The evaluation applied the image criteria score (ICS) without conventional reference images. Results: In 99% of the lateral radiographs of the cervical spine, all vertebral bodies could be completed delineated using the manual mode, but only 76% of the images processed by the system-imminent parameters showed all vertebral bodies. Thus, the manual mode enabled the evaluation of up to two additional more caudal vertebral bodies. The manual mode processing was significantly better concerning object size and processing artifacts. This optimized image processing and the resultant minimization of supplementary investigations was calculated to correspond to a theoretical dose reduction of about 50%. (orig.) [de

Characterization of an in vivo thyroid 131I monitoring system using an imaging plate

International Nuclear Information System (INIS)

Hirota, Masahiro; Saze, Takuya; Nishizawa, Kunihide

2004-01-01

The effects of neck diameter, thyroid volume, and prethyroid tissue thickness on a count-activity conversion coefficient and the detection limit of a thyroid 131 I monitoring system with an imaging plate (IP) were estimated by using an anthropomorphic thyroid-neck phantom. The conversion coefficient and detection limit of the IP system was approximately constant for normal Japanese adults regardless of their neck diameters, thyroid volumes, and prethyroid tissue thicknesses. The IP system is a new option for thyroid 131 I monitoring

Imaging microchannel plate detectors for XUV sky survey experiments

International Nuclear Information System (INIS)

Barstow, M.A.; Fraser, G.W.; Milward, S.R.

1986-01-01

Attention is given to the development of microchannel plate detectors for the Wide Field Camera (WFC) XUV (50-300 A) sky survey experiment on Rosat. A novel feature of the detector design is that the microchannel plates and their resistive anode readout are curved to the same radius as the WFC telescope focal surface. It is shown that curving the channel plates is not detrimental to gain uniformity. The paper describes the design of a curved resistive anode readout element and contrasts the present measurements of spatial resolution, global and local uniformity and temperature coefficient of resistance with the poor performance recently ascribed to resistive anodes in the literature. 18 references

Measurement of leakage dose distribution from Crookes tube using imaging plate

International Nuclear Information System (INIS)

Fujibuchi, Toshioh; Obara, Satoshi; Inoue, Hajime; Kato, Hideyuki; Kobayashi, Ikuo; Hosoda, Masahiro

2011-01-01

Crookes tube is used on an educational site in the junior high school and the high school, etc. for the purpose to learn the character of cathode rays. When using the tube, X rays are generated, however, there is few example of confirming in which direction to scatter in detail. Understanding how the distribution of the leakage dose is important because of efficient exposure decrease. The distribution of X rays generated from Crookes tube was measured by arranging imaging plates in six surroundings to enclose Crookes tube. The electron collided with a metal target and X rays had extended backward. The dose was greatly different depending on the direction. When experimenting with Crookes tube, it is necessary to consider not only the dose but also distribution. (author)

Image quality in conventional film screen system, digital phosphor storage plate mammography in magnification technique and digital mammography in CCD-technique

International Nuclear Information System (INIS)

Schulz-Wendtland, R.; Aichinger, U.; Boehner, C.; Dobritz, M.; Bautz, W.; Saebel, M.

2000-01-01

Purpose: Comparison of image quality between conventional film screen system, digital phosphor storage plate mammography in magnification technique and digital mammography in CCD-technique. Materials and Methods: Radiograms of a RMI-mammography phantom were acquired using a conventional film screen system, two digital storage plate systems and two digital systems in CCD-technique. Additionally, the radiograms of one digital phosphor storage plate system were post-processed emphasizing contrast and included in the comparison. Results: The detectability of details was the best with the digital mammography in CCD-technique in comparison with the conventional film screen technique resp. digital phosphor storage plate in magnification technique. Conclusions: Based on these results there is the possibility to replace the conventional film screen system by further studies - this has to be confirmed. (orig.) [de

Applicability and performance of an imaging plate at subzero temperatures

International Nuclear Information System (INIS)

Sakoda, Akihiro; Ishimori, Yuu; Hanamoto, Katsumi; Kawabe, Atsushi; Kataoka, Takahiro; Nagamatsu, Tomohiro; Yamaoka, Kiyonori

2010-01-01

The performance of imaging plates (IPs) has not been studied at temperatures lower than 0 o C. In the present study, an IP was irradiated with gamma rays emitted from the mineral monazite at temperatures between -80 and 30 o C to determine its fundamental properties. The IP response as a function of irradiation time was found to be linear, suggesting that the IP works properly at low temperatures. Fading, an effect which should be considered at temperatures of more than 0 o C, was not observed at -30 and -80 o C. Furthermore, the fading-corrected PSL value of the IP irradiated at -80 o C was lower than at other temperatures (30, 5 and -30 o C). This can be explained by thermostimulated luminescence (TSL). Since the only intensive TSL peak in the temperature range from -80 to 30 o C is present at about -43 o C, some of the electrons trapped at F centers recombine with holes through the process of TSL before the stored radiation image is read out at room temperature. This finding suggests that the apparent sensitivity of the IP is lower at -80 o C although it is similar to sensitivities between -30 and 30 o C. This low sensitivity should be corrected to perform quantitative measurements.

Depth profiling of hydrogen in ferritic/martensitic steels by means of a tritium imaging plate technique

International Nuclear Information System (INIS)

Otsuka, Teppei; Tanabe, Tetsuo

2013-01-01

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

Experimental and computational investigations of heat and mass transfer of intensifier grids

International Nuclear Information System (INIS)

Kobzar, Leonid; Oleksyuk, Dmitry; Semchenkov, Yuriy

2015-01-01

The paper discusses experimental and numerical investigations on intensification of thermal and mass exchange which were performed by National Research Centre ''Kurchatov Institute'' over the past years. Recently, many designs of heat mass transfer intensifier grids have been proposed. NRC ''Kurchatov Institute'' has accomplished a large scope of experimental investigations to study efficiency of intensifier grids of various types. The outcomes of experimental investigations can be used in verification of computational models and codes. On the basis of experimental data, we derived correlations to calculate coolant mixing and critical heat flux mixing in rod bundles equipped with intensifier grids. The acquired correlations were integrated in subchannel code SC-INT.

Change of characteristic curves using light emission spectrum of the intensifying screens

International Nuclear Information System (INIS)

Yoon, Chul Ho; Kang, Hong Seok; Lee, In Ja; Huh, Joon

1990-01-01

This report is study about difference of H-D curve in regular film and ortho type film, and obtained results as follows: 1. In the blue-color emission intensifying screen, ortho type films and in the green-color emission intensifying screens, regular type are decreased in their gradient. 2. When joint use of regular type film and ortho type film, the gradient difference not seen in blue color screen. 3. The gradient difference seen clearly in G4, KM screens (green color emission intensifying). Especially, in part of high film density, the gradient difference are great. So we have to right use of screen and film because not matched used of there the sensitivity and gradient are decrease

Distribution of radiocesium in bamboo leaves, roots and shoots. Application of an imaging plate

International Nuclear Information System (INIS)

Minowa, Haruka; Ogata, Yoshimune; Satou, Yukihiko

2012-01-01

When radiocesium is taken into a wild plant accidentally, it will circulate for a certain period of time. Bamboo is that in some cases relative high concentration of radiocesium have been reported. Radiocesium is considered to be concentrated in bamboo shoot by translocation in plants from bamboo leaves or roots. In this study, to investigate the behavior of radiocesium, shoots, roots, branches and leaves of bamboo (Phyllostadhys edulis) were collected at Yamakiya area, Kawamata-machi, Date-gun, Fukushima Prefecture. Radiation image analysis was conducted using an imaging plate BAS 2040 (Fujifilm) and an image analyzer Typhoon FLA7000 (GE Healthcare Japan Corp.). The content of radiocesium was about 500 Bq for "1"3"4Cs and 700 Bq for "1"3"7Cs per the bamboo shoot (500 g approximately). In the edible parts of bamboo shoots, the skin of bamboo shoots and leaves of newly-grown, radiocesium uptake was in high concentration, especially at the tip. (author)

Comparison between radiation exposure levels using an image intensifier and a flat-panel detector-based system in image-guided central venous catheter placement in children weighing less than 10 kg

Energy Technology Data Exchange (ETDEWEB)

Miraglia, Roberto; Maruzzelli, Luigi; Cortis, Kelvin; Gerasia, Roberta; Maggio, Simona; Luca, Angelo [Diagnostic and Therapeutic Services, Mediterranean Institute for Transplantation and Advanced Specialized Therapies (ISMETT), Palermo (Italy); Piazza, Marcello [Department of Anesthesia, Mediterranean Institute for Transplantation and Advanced Specialized Therapies (ISMETT), Palermo (Italy); Tuzzolino, Fabio [Department of Information Technology, Mediterranean Institute for Transplantation and Advanced Specialized Therapies (ISMETT), Palermo (Italy)

2014-09-10

Ultrasound-guided central venous puncture and fluoroscopic guidance during central venous catheter (CVC) positioning optimizes technical success and lowers the complication rates in children, and is therefore considered standard practice. The purpose of this study was to compare the radiation exposure levels recorded during CVC placement in children weighing less than 10 kg in procedures performed using an image intensifier-based angiographic system (IIDS) to those performed in a flat-panel detector-based interventional suite (FPDS). A retrospective review of 96 image-guided CVC placements, between January 2008 and October 2013, in 49 children weighing less than 10 kg was performed. Mean age was 8.2 ± 4.4 months (range: 1-22 months). Mean weight was 7.1 ± 2.7 kg (range: 2.5-9.8 kg). The procedures were classified into two categories: non-tunneled and tunneled CVC placement. Thirty-five procedures were performed with the IIDS (21 non-tunneled CVC, 14 tunneled CVC); 61 procedures were performed with the FPDS (47 non-tunneled CVC, 14 tunneled CVC). For non-tunneled CVC, mean DAP was 113.5 ± 126.7 cGy cm{sup 2} with the IIDS and 15.9 ± 44.6 cGy . cm{sup 2} with the FPDS (P < 0.001). For tunneled CVC, mean DAP was 84.6 ± 81.2 cGy . cm{sup 2} with the IIDS and 37.1 ± 33.5 cGy cm{sup 2} with the FPDS (P = 0.02). The use of flat-panel angiographic equipment reduces radiation exposure in small children undergoing image-guided CVC placement. (orig.)

Optics for People Stuck in Traffic: License Plates.

Science.gov (United States)

Chagnon, Paul

1995-01-01

Explains the theory behind the working of Scotchlite, a retrodirective material used for coating automotive license plates, and the Ensure Imaging System that allows law enforcement officers to verify the authenticity of the plate. (JRH)

Thin plate spline feature point matching for organ surfaces in minimally invasive surgery imaging

Science.gov (United States)

Lin, Bingxiong; Sun, Yu; Qian, Xiaoning

2013-03-01

Robust feature point matching for images with large view angle changes in Minimally Invasive Surgery (MIS) is a challenging task due to low texture and specular reflections in these images. This paper presents a new approach that can improve feature matching performance by exploiting the inherent geometric property of the organ surfaces. Recently, intensity based template image tracking using a Thin Plate Spline (TPS) model has been extended for 3D surface tracking with stereo cameras. The intensity based tracking is also used here for 3D reconstruction of internal organ surfaces. To overcome the small displacement requirement of intensity based tracking, feature point correspondences are used for proper initialization of the nonlinear optimization in the intensity based method. Second, we generate simulated images from the reconstructed 3D surfaces under all potential view positions and orientations, and then extract feature points from these simulated images. The obtained feature points are then filtered and re-projected to the common reference image. The descriptors of the feature points under different view angles are stored to ensure that the proposed method can tolerate a large range of view angles. We evaluate the proposed method with silicon phantoms and in vivo images. The experimental results show that our method is much more robust with respect to the view angle changes than other state-of-the-art methods.

The role of heat pipes in intensified unit operations

International Nuclear Information System (INIS)

Reay, David; Harvey, Adam

2013-01-01

Heat pipes are heat transfer devices that rely, most commonly, on the evaporation and condensation of a working fluid contained within them, with passive pumping of the condensate back to the evaporator. They are sometimes referred to as ‘thermal superconductors’ because of their exceptionally high effective thermal conductivity (substantially higher than any metal). This, together with several other characteristics make them attractive to a range of intensified unit operations, particularly reactors. The majority of modern computers deploy heat pipes for cooling of the CPU. The application areas of heat pipes come within a number of broad groups, each of which describes a property of the heat pipe. The ones particularly relevant to chemical reactors are: i. Separation of heat source and sink. ii. Temperature flattening, or isothermalisation. iii. Temperature control. Chemical reactors, as a heat pipe application area, highlight the benefits of the heat pipe based on isothermalisation/temperature flattening device and on being a highly effective heat transfer unit. Temperature control, done passively, is also of relevance. Heat pipe technology offers a number of potential benefits to reactor performance and operation. The aim of increased yield of high purity, high added value chemicals means less waste and higher profitability. Other intensified unit operations, such as those employing sorption processes, can also profit from heat pipe technology. This paper describes several variants of heat pipe and the opportunities for their use in intensified plant, and will give some current examples. -- Highlights: ► Heat pipes – thermal superconductors – can lead to improved chemical reactor performance. ► Isothermalisation within a reactor vessel is an ideal application. ► The variable conductance heat pipe can control reaction temperatures within close limits. ► Heat pipes can be beneficial in intensified reactors

X-ray Talbot interferometry with capillary plates

International Nuclear Information System (INIS)

Momose, Atsushi; Kawamoto, Shinya

2006-01-01

An X-ray Talbot interferometer consisting of two capillary plates, which were used as X-ray amplitude gratings, was evaluated for X-ray phase imaging. A theoretical aspect of capillary X-ray Talbot interferometry is presented with a preliminary operation result using synchrotron radiation. A two-dimensional X-ray Talbot effect, or self-imaging effect, which was the basis of Talbot interferometry, was observed with the capillary plate, and moire images formed by the X-ray Talbot interferometer exhibited contrasts corresponding to the differential phase shift caused by phase objects placed in front of the interferometer. Finally, the possibility of quantitative phase measurement with a fringe scanning technique is discussed. (author)

Spirit Beside 'Home Plate,' Sol 1809

Science.gov (United States)

2009-01-01

NASA Mars Exploration Rover Spirit used its navigation camera to take the images assembled into this 120-degree view southward after a short drive during the 1,809th Martian day, or sol, of Spirit's mission on the surface of Mars (February 3, 2009). Spirit had driven about 2.6 meters (8.5 feet) that sol, continuing a clockwise route around a low plateau called 'Home Plate.' In this image, the rocks visible above the rovers' solar panels are on the slope at the northern edge of Home Plate. This view is presented as a cylindrical projection with geometric seam correction.

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

International Nuclear Information System (INIS)

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

2013-01-01

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.

Visualization and quantification of capillary drainage in the pore space of laminated sandstone by a porous plate method using differential imaging X-ray microtomography

Science.gov (United States)

Lin, Qingyang; Bijeljic, Branko; Rieke, Holger; Blunt, Martin J.

2017-08-01

The experimental determination of capillary pressure drainage curves at the pore scale is of vital importance for the mapping of reservoir fluid distribution. To fully characterize capillary drainage in a complex pore space, we design a differential imaging-based porous plate (DIPP) method using X-ray microtomography. For an exemplar mm-scale laminated sandstone microcore with a porous plate, we quantify the displacement from resolvable macropores and subresolution micropores. Nitrogen (N2) was injected as the nonwetting phase at a constant pressure while the porous plate prevented its escape. The measured porosity and capillary pressure at the imaged saturations agree well with helium measurements and experiments on larger core samples, while providing a pore-scale explanation of the fluid distribution. We observed that the majority of the brine was displaced by N2 in macropores at low capillary pressures, followed by a further brine displacement in micropores when capillary pressure increases. Furthermore, we were able to discern that brine predominantly remained within the subresolution micropores, such as regions of fine lamination. The capillary pressure curve for pressures ranging from 0 to 1151 kPa is provided from the image analysis compares well with the conventional porous plate method for a cm-scale core but was conducted over a period of 10 days rather than up to few months with the conventional porous plate method. Overall, we demonstrate the capability of our method to provide quantitative information on two-phase saturation in heterogeneous core samples for a wide range of capillary pressures even at scales smaller than the micro-CT resolution.

Usefulness of DICOM headers in the analysis of two biplane X-ray systems setting (image intensifier and flat panel) used in pediatric interventional cardiology in Chile

International Nuclear Information System (INIS)

Ubeda, C.; Vergara, F.

2009-01-01

The setting of two biplane X ray systems were evaluated (image intensifier (II) and flat panel (PP)), through DICOM tags from 32 images created during the characterization of both systems. The technical parameters adjusted for systems were: 63,8 to 80,0 kV and 15,0 to 388,0 mA, for the system with II and 52,0 to 77,0 kV and 25,0 to 476,0 mA, for the system with PP detector. Both equipment presented a different mA adjustment, when moving from fluoroscopy modes low dose (FL), medium dose (FM) and high dose (FH) to cine mode (CI). Two dosimetric quantities were evaluated, the first one was the dose-area product (DAP) which gave as a result for FB mode, between 0,03 to 0,35 uGycm 2 /image (II) and from 0,05 a 0,69 uGycm 2 /image (PP), when the polymethyl methacrylate (PMMA) thickness was incremented from 4 to 16 cm. In cine mode the DAP quantity showed, percentage values from 24 to -1 % for the same PMMA increment. Skin cumulative dose was the second quantity evaluated and showed an increment of incident air kerma (KAI)/image in factors from 17 to 35 (II) and 15 to 28 (PP) when used in CI mode instead of FB mode, to the different PMMA thicknesses used. This dose increment for CI mode must be considered by cardiologists, to use the fluoroscopic run as an alternative to document part of the procedures when there is no need to use a high quality image (author)

A License Plate Locating Method Based on Tophat-bothat Changing and Line Scanning

International Nuclear Information System (INIS)

Hou, P G; Zhao, J; Liu, M

2006-01-01

The automatic license plate recognition is an important technique to obtain traffic information, it mixes computer vision, image processing techniques and pattern recognition techniques, it is an important technique in intelligent traffic system. In a vehicle license plate recognition system, plate region detection is the key step before the final recognition. This article introduces the whole process of plate region detection. Top - hat and bot - hat transformation are used for enhancing the image contrast in this paper, and wavelet threshold method is used as image filter, and a improved line scanning is used for plate region detection at last. This method has strong practicability. The experimental results demonstrate that the method introduced in this paper is effective

Evaluation of In-Vacuum Imaging Plate Detector for X-Ray Diffraction Microscopy

International Nuclear Information System (INIS)

Nishino, Yoshinori; Takahashi, Yukio; Yamamoto, Masaki; Ishikawa, Tetsuya

2007-01-01

We performed evaluation tests of a newly developed in-vacuum imaging plate (IP) detector for x-ray diffraction microscopy. IP detectors have advantages over direct x-ray detection charge-coupled device (CCD) detectors, which have been commonly used in x-ray diffraction microscopy experiments, in the capabilities for a high photon count and for a wide area. The detector system contains two IPs to make measurement efficient by recording data with the one while reading or erasing the other. We compared speckled diffraction patterns of single particles taken with the IP and a direct x-ray detection CCD. The IP was inferior to the CCD in spatial resolution and in signal-to-noise ratio at a low photon count

Contribution to numerical radiology. Study of a bidimensional imaging device that use Electrically Stimulated Luminescence. The case of mammography

International Nuclear Information System (INIS)

Ayral, Jean-Luc

1990-01-01

Projection radiography is in a fast change period. This work describes the study and demonstration of a new type of 2D flat X-Ray sensor for mammography and delivering a digital signal. X-ray transmission study of breast tissues leads to: a- definition of X-Ray photons properties for optimized signal-to-noise ratio, and b-specifications of a 2D X-Ray sensor such as mean exposure, dynamic range and pixel size. Then the X-Ray detection processes using a direct or a delayed luminescence mechanism are reviewed. The detailed analysis of the different ways for detecting visible photons is combined with the System specifications (pixel size, image reading time) in order to characterize (from a signal-to-noise ratio aspect) an X-Ray imaging system integrating a delayed luminescence property. The imaging plate and associated luminescent material are specified by their minimum X-Ray absorption and conversion gain. The Gudden- Pohl effect, or Electrically Stimulated Luminescence (ESL) is experimentally studied and quantified under X-Ray excitation in ZnCdS: Cu, Al materials. An original UV sensitization technique opens us the way to highly reproducible results and large sensitivity. The obtained information storage time in the material is compatible with a delayed image reading. These results allow the achievement of an X-Ray imaging demonstrator integrating the ESL imaging plate, an intensified CCD sensor and the sensitization technique. First images are obtained. Further conception of real dimension X-Ray imaging System for mammography is described. (author) [fr

The Golosyiv plate archive digitisation

Science.gov (United States)

Sergeeva, T. P.; Sergeev, A. V.; Pakuliak, L. K.; Yatsenko, A. I.

2007-08-01

The plate archive of the Main Astronomical Observatory of the National Academy of Sciences of Ukraine (Golosyiv, Kyiv) includes about 85 000 plates which have been taken in various observational projects during 1950-2005. Among them are about 25 000 of direct northern sky area plates and more than 600 000 plates containing stellar, planetary and active solar formations spectra. Direct plates have a limiting magnitude of 14.0-16.0 mag. Since 2002 we have been organising the storage, safeguarding, cataloguing and digitization of the plate archive. The very initial task was to create the automated system for detection of astronomical objects and phenomena, search of optical counterparts in the directions of gamma-ray bursts, research of long period, flare and other variable stars, search and rediscovery of asteroids, comets and other Solar System bodies to improve the elements of their orbits, informational support of CCD observations and space projects, etc. To provide higher efficiency of this work we have prepared computer readable catalogues and database for 250 000 direct wide field plates. Now the catalogues have been adapted to Wide Field Plate Database (WFPDB) format and integrated into this world database. The next step will be adaptation of our catalogues, database and images to standards of the IVOA. Some magnitude and positional accuracy estimations for Golosyiv archive plates have been done. The photometric characteristics of the images of NGC 6913 cluster stars on two plates of the Golosyiv's double wide angle astrograph have been determined. Very good conformity of the photometric characteristics obtained with external accuracies of 0.13 and 0.15 mag. has been found. The investigation of positional accuracy have been made with A3± format fixed bed scanner (Microtek ScanMaker 9800XL TMA). It shows that the scanner has non-detectable systematic errors on the X-axis, and errors of ± 15 μm on the Y-axis. The final positional errors are about ± 2 μm (�

Distal radius plate of CFR-PEEK has minimal effect compared to titanium plates on bone parameters in high-resolution peripheral quantitative computed tomography: a pilot study.

Science.gov (United States)

de Jong, Joost J A; Lataster, Arno; van Rietbergen, Bert; Arts, Jacobus J; Geusens, Piet P; van den Bergh, Joop P W; Willems, Paul C

2017-02-27

Carbon-fiber-reinforced poly-ether-ether-ketone (CFR-PEEK) has superior radiolucency compared to other orthopedic implant materials, e.g. titanium or stainless steel, thus allowing metal-artifact-free postoperative monitoring by computed tomography (CT). Recently, high-resolution peripheral quantitative CT (HRpQCT) proved to be a promising technique to monitor the recovery of volumetric bone mineral density (vBMD), micro-architecture and biomechanical parameters in stable conservatively treated distal radius fractures. When using HRpQCT to monitor unstable distal radius fractures that require volar distal radius plating for fixation, radiolucent CFR-PEEK plates may be a better alternative to currently used titanium plates to allow for reliable assessment. In this pilot study, we assessed the effect of a volar distal radius plate made from CFR-PEEK on bone parameters obtained from HRpQCT in comparison to two titanium plates. Plates were instrumented in separate cadaveric human fore-arms (n = 3). After instrumentation and after removal of the plates duplicate HRpQCT scans were made of the region covered by the plate. HRpQCT images were visually checked for artifacts. vBMD, micro-architectural and biomechanical parameters were calculated, and compared between the uninstrumented and instrumented radii. No visible image artifacts were observed in the CFR-PEEK plate instrumented radius, and errors in bone parameters ranged from -3.2 to 2.6%. In the radii instrumented with the titanium plates, severe image artifacts were observed and errors in bone parameters ranged between -30.2 and 67.0%. We recommend using CFR-PEEK plates in longitudinal in vivo studies that monitor the healing process of unstable distal radius fractures treated operatively by plating or bone graft ingrowth.

Intensified coastal development behind nourished beaches

Science.gov (United States)

Armstrong, Scott; Lazarus, Eli; Limber, Patrick; Goldstein, Evan; Thorpe, Curtis; Ballinger, Rhoda

2016-04-01

Population density, housing development, and property values in coastal counties along the U.S. Atlantic and Gulf Coasts continue to rise despite increasing hazard from storm impacts. Since the 1970s, beach nourishment, which involves importing sand to deliberately widen an eroding beach, has been the main strategy in the U.S. for protecting coastal properties from erosion and flooding hazards. Paradoxically, investment in hazard protection may intensify development. Here, we examine the housing stock of all existing shorefront single-family homes in Florida - a microcosm of U.S. coastal hazards and development - to quantitatively compare development in nourishing and non-nourishing towns. We find that nourishing towns now account for more than half of Florida's coastline, and that houses in nourishing towns are larger and more numerous. Even as the mean size of single-family homes nationwide has grown steadily since 1970, Florida's shorefront stock has exceeded the national average by 34%, and in nourishing towns by 45%. This emergent disparity between nourishing and non-nourishing towns in Florida demonstrates a pattern of intensifying coastal risk, and is likely representative of a dominant trend in coastal development more generally. These data lend empirical support to the hypothesis that US coastal development and hazard mitigation through beach nourishment have become dynamically coupled.

In vitro comparison between the image obtained using PSP plates and Kodak E-speed films.

Science.gov (United States)

Petel, R; Yaroslavsky, L; Kaffe, I

2014-07-01

The aim of this study was to compare the intra-oral radiographic images obtained by a PSP digital radiography system ("Orex", Israel) with that obtained using Kodak Ultra speed films in terms of image quality, radiation dosage and diagnostic value. The physical measurement of image quality was conducted with an aluminum step-wedge. Radiation dosage was measured with a dosimeter. Fog and base levels were measured by developing unexposed films and scanning unexposed PSP plates. The in vitro model included preparation and radiographic evaluation of approximal artificial lesions in premolars and molars in depths ranging from 0.25 mm to 1.00 mm. Radiographs were evaluated for the existence of a lesion and its size by 8 experienced clinicians. Relative contrast was similar in both methods. The resolving power of the digital system was lower than that of the E-speed film. As for the subjective evaluation of artificial lesions, there was no significant difference between the two methods excluding those tooth images without lesions, where the analog method was found to be more accurate. The PSP system ("Orex") provides good image quality and diagnostic information with reduced exposure when compared with E-speed film.

RECOGNITION DESIGN OF LICENSE PLATE AND CAR TYPE USING TESSERACT OCR AND EmguCV

Directory of Open Access Journals (Sweden)

Antonius Herusutopo

2012-10-01

Full Text Available The goal of the research is to design and implement software that can recognize license plates and car types from images. The method used for the research is soft computing using library of EmguCV. There are four phases in creating the software, i.e., input image process, pre-processing, training processing and recognition. Firstly, user enters the car image. Then, the program reads and does pre-processing the image from bitmap form into vector. The next process is training process, which is learning phase in order the system to be able recognize an object (in this case license plate and car type, and in the end is the recognition process itself. The result is data about the car types and the license plates that have been entered. Using simulation, this software successfully recognized license plate by 80.223% accurate and car type 75% accurate.Keywords: Image; Pre-Processing; License plate and Car Type Recognition, Training

Digital Archive of UkrVO: first results of MAO NASU Solar System Bodies photographic plate processing

Science.gov (United States)

Ivanov, G.; Pakuliak, L.; Shatokhina, S.; Yizhakevych, E.; Kazantseva, L.; Andruk, V.

The digitizing and processing of photographic plates with the images of the outer planets and their satellites from the archive collections of MAO NASU and AO of Kiev university included into the UkrVO Joint Digital Archive (JDA) have been made. Plates were obtained in the last half of the 20th century. The digitizing of JDA archive plates and inclusion of plate preview images into GPA database has been under way, using two models of flatbed scanners: Microtek ScanMaker 9800XL TMA and Epson Expression 10000XL. The database with metadata of plates is allocated on the computational resources of MAO NASU (http://gua.db.ukr-vo.org). Plates have been scanned at 16-bits grey dynamic range, with a resolution of 1200-1600 dpi, and saved in TIFF format. Linear dimensions of images are up to 13 thousand pixels (for plates 30.30 cm). The astrometric and photometric calibration procedures have been done in the LINUX-MIDASROMAFOT environment and Tycho-2 as reference with the image processing procedure specially developed for digitized images of huge linear dimensions on the basis of the image inherent traits. First results of digitized plate processing give the rms errors of 10 and 20 mas for RA, DEC respectively. (O-C) for plates with Pluto in comparison to JPL PLU021.DE405 has been derived of 140(RA) and 270(DEC) mas.

LICENSE PLATE LOCALIZATION USING GABOR FILTERS AND NEURAL NETWORKS

OpenAIRE

Sami Ktata; Faouzi Benzarti; Hamid Amiri

2013-01-01

Vehicle License Plate Detection (LPD) is an important step for the vehicle plate recognition which can be used in the intelligent transport systems. Many methods have been proposed for the detection of license plates based on: Mathematical morphology, Discrete Wavelet Transform, Hough Transform and others. In general, an LPR system includes four main parts: Vehicle image acquisition, license plate detection, character segmentation and character recognition. In this study, we present a robust ...

Pc-based car license plate reading

Science.gov (United States)

Tanabe, Katsuyoshi; Marubayashi, Eisaku; Kawashima, Harumi; Nakanishi, Tadashi; Shio, Akio

1994-03-01

A PC-based car license plate recognition system has been developed. The system recognizes Chinese characters and Japanese phonetic hiragana characters as well as six digits on Japanese license plates. The system consists of a CCD camera, vehicle sensors, a strobe unit, a monitoring center, and an i486-based PC. The PC includes in its extension slots: a vehicle detector board, a strobe emitter board, and an image grabber board. When a passing vehicle is detected by the vehicle sensors, the strobe emits a pulse of light. The light pulse is synchronized with the time the vehicle image is frozen on an image grabber board. The recognition process is composed of three steps: image thresholding, character region extraction, and matching-based character recognition. The recognition software can handle obscured characters. Experimental results for hundreds of outdoor images showed high recognition performance within relatively short performance times. The results confirmed that the system is applicable to a wide variety of applications such as automatic vehicle identification and travel time measurement.

Dispersal limitation drives successional pathways in Central Siberian forests under current and intensified fire regimes.

Science.gov (United States)

Tautenhahn, Susanne; Lichstein, Jeremy W; Jung, Martin; Kattge, Jens; Bohlman, Stephanie A; Heilmeier, Hermann; Prokushkin, Anatoly; Kahl, Anja; Wirth, Christian

2016-06-01

Fire is a primary driver of boreal forest dynamics. Intensifying fire regimes due to climate change may cause a shift in boreal forest composition toward reduced dominance of conifers and greater abundance of deciduous hardwoods, with potential biogeochemical and biophysical feedbacks to regional and global climate. This shift has already been observed in some North American boreal forests and has been attributed to changes in site conditions. However, it is unknown if the mechanisms controlling fire-induced changes in deciduous hardwood cover are similar among different boreal forests, which differ in the ecological traits of the dominant tree species. To better understand the consequences of intensifying fire regimes in boreal forests, we studied postfire regeneration in five burns in the Central Siberian dark taiga, a vast but poorly studied boreal region. We combined field measurements, dendrochronological analysis, and seed-source maps derived from high-resolution satellite images to quantify the importance of site conditions (e.g., organic layer depth) vs. seed availability in shaping postfire regeneration. We show that dispersal limitation of evergreen conifers was the main factor determining postfire regeneration composition and density. Site conditions had significant but weaker effects. We used information on postfire regeneration to develop a classification scheme for successional pathways, representing the dominance of deciduous hardwoods vs. evergreen conifers at different successional stages. We estimated the spatial distribution of different successional pathways under alternative fire regime scenarios. Under intensified fire regimes, dispersal limitation of evergreen conifers is predicted to become more severe, primarily due to reduced abundance of surviving seed sources within burned areas. Increased dispersal limitation of evergreen conifers, in turn, is predicted to increase the prevalence of successional pathways dominated by deciduous hardwoods

^<90>Sr in mammal teeth taken in the Semipalatinsk Test Site measured by imaging plates

OpenAIRE

Toyoda, Shin; Pivovarov, Sergey; Hoshi, Masaharu; Seredavina, Tatyana

2012-01-01

The concentrations of 90Sr in mammal teeth taken in north-west part of Semipalatinsk Test Site were measured by using imaging plates. The highest concentration detected in the present study was 13Bq/g, being comparable with the values previously detected in cow teeth from South Ural region. It suggests that, at least locally, the soil in north-west part of the Test Site is possibly highly contaminated. It would be necessary to investigate the source of this high level of contamination, such a...

Energy response of an imaging plate exposed to standard beta sources

International Nuclear Information System (INIS)

Gonzalez, A.L.; Li, H.; Mitch, M.; Tolk, N.; Duggan, D.M.

2002-01-01

Imaging plates (IPs) are a reusable media, which when exposed to ionizing radiation, store a latent image that can be read out with a red laser as photostimulated luminescence (PSL). They are widely used as a substitute for X-ray films for diagnostic studies. In diagnostic radiology this technology is known as computed radiography. In this work, the energy response of a commercial IP to beta-particle reference radiation fields used for calibrations at the National Institute of Standards and Technology was investigated. The absorbed dose in the active storage phosphor layer was calculated following the scaling procedure for depth dose for high Z materials with reference to water. It was found that the beta particles from Pm-147 and Kr-85 gave 68% and 24% higher PSL responses than that induced by Sr-90, respectively, which was caused by the different PSL detection efficiencies. In addition, normalized response curves of the IPs as a function of depth in polystyrene were measured and compared with the data measured using extrapolation chamber techniques. The difference between both sets of data resulted from the continuous energy change as the beta particle travels across the material, which leads to a different PSL response

Design and test of a high resolution plastic scintillating fiber detector with intensified CCD readout

International Nuclear Information System (INIS)

Rebourgeard, P.

1991-01-01

We present the design of a particle detector involving a coherent array of 100 000 plastic scintillating microfibers, with an individual core diameter around 50 micrometers, and an intensified bidimensional CCD array. We investigate both theoretically and experimentally the use of polystyrene based scintillators in optical multimodal fibers. The isotropic excitation of modes and the characteristics of energy transfers between the polystyrene matrix and the added fluorescent dyes are of particular interest. An experimental approach is proposed and applied to the development of a new binary scintillator. In order to study the transmission of the signal from the interaction area to the output face, we specify the loss factors, the resolution and the signal to noise ratio within the fiber array. The low light level at the output face of the detector leads us to use image intensifiers in photon counting mode. This requires a detailed analysis of resolutions, gain, noise and detectivity concepts. We propose to describe these strongly correlated notions by the moment generation formalism. Thus, a previous modelisation of the photoelectronic devices allows us to evaluate the performance of the readout chain. A complete detector has been assembled and tested on a high energy hadron beam; the measurements are in good agreement with the modelisation [fr

Emulsification in novel ultrasonic cavitation intensifying bag reactors

NARCIS (Netherlands)

Zwieten, van Ralph; Verhaagen, Bram; Schroën, Karin; Fernández Rivas, David

2017-01-01

Cavitation Intensifying Bags (CIBs), a novel reactor type for use with ultrasound, have been recently proposed as a scaled-up microreactor with increased energy efficiencies. We now report on the use of the CIBs for the preparation of emulsions out of hexadecane and an SDS aqueous solution. The

Quality control of nuclear fuel plates using digital image processing techniques

International Nuclear Information System (INIS)

Salinas, Renato; Radd, Ulrich; Coronado, Harold; Olivares, Luis

2003-01-01

The Chilean Atomic Energy Commission (CCHEN) has developed the technology requires to manufacture low enriched uranium-235 nuclear fuel elements used in non-power reactor applications and in research. These fuel plates are assembled in two nuclear facilities located at La Reina (RECH-1) and Lo Aguirre where the present work was developed. Furthermore since high quality standards have been met, these facilities are able to export these nuclear fuel plates to foreign countries. Each MTR fuel elements consists of 16 low enriched uranium silicide (U 3 Si 2 ) fuel plates. A stringent quality assurance program requires among others, homogeneity measurements of uranium surface density values of these fuel plates, which are traditionally accomplished with optical densitometry methods. We have implemented and alternative technique which uses computer vision to determine uranium surface density values in these fuel plates. Both techniques are compared. Advantages of machine vision methods include considerable time saving and a complete quantitative evaluation of uranium densities as compared to the sparse technique involved in the optical densitometry method (Au)

A large area detector for x-ray applications

International Nuclear Information System (INIS)

Rodricks, B.; Huang, Qiang; Hopf, R.; Wang, Kemei.

1993-01-01

A large area detector for x-ray synchrotron applications has been developed. The front end of this device consist of a scintillator coupled to a fiber-optic taper. The fiber-optic taper is comprised of 4 smaller (70 mm x 70 mm) tapers fused together in a square matrix giving an active area of 140 mm x 140 mm. Each taper has a demagnification of 5.5 resulting in four small ends that are 12 mm diagonally across. The small ends of each taper are coupled to four microchannel-plate-based image intensifiers. The output from each image intensifier is focused onto a Charge Coupled Device (CCD) detector. The four CCDs are read out in parallel and are independently controlled. The image intensifiers also act as fast (20 ns) electronic shutters. The system is capable of displaying images in real time. Additionally, with independent control on the readout of each row of data from the CCD, the system is capable of performing high speed imaging through novel readout manipulation

Simple determination of 99Tc in radioactive waste using Tc extraction disk and imaging plates

International Nuclear Information System (INIS)

Kameo, Y.; Katayama, A.; Hoshi, A.; Haraga, T.; Nakashima, M.

2010-01-01

A simple method was developed for determination of 99 Tc in low-level radioactive waste: Technetium-99 retained by a solid phase extraction disk was directly measured with imaging plates system. It was found that more than 97% of Tc were retained by the disk from a solution of pH 2 to 12, whereas depth profile of Tc in the disk, which greatly influences the counting efficiency, depended on solution pH. The present method was successfully applied to actual radioactive liquid waste samples arising from nuclear research facilities.

A unidirectional subwavelength focusing near-field plate

Energy Technology Data Exchange (ETDEWEB)

Imani, Mohammadreza F.; Grbic, Anthony [Radiation Laboratory, Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109 (United States)

2014-01-28

Near-field plates consist of non-periodically patterned surfaces that can overcome the diffraction limit and confine electromagnetic fields to subwavelength dimensions. Previous near-field plates experimentally demonstrated extreme field tailoring capabilities. However, their performance suffered from radiation/reflection in undesired directions, those other than the subwavelength focus. This issue can limit the practical use of near-field plates. In this paper, we address this issue by designing a unidirectional near-field plate that can form a subwavelength focal pattern, while suppressing the field radiated/reflected in other directions. The design and operation of the proposed unidirectional near-field plate are verified through full-wave simulation. The unidirectional near-field plate may find application in high resolution imaging and probing, high density data storage, and wireless power transfer systems. As an example, its utility as a high resolution probe is demonstrated through full-wave electromagnetic simulation.

Automated Cart with VIS/NIR Hyperspectral Reflectance and Fluorescence Imaging Capabilities

Directory of Open Access Journals (Sweden)

Alan M. Lefcourt

2016-12-01

Full Text Available A system to take high-resolution Visible/Near Infra-Red (VIS/NIR hyperspectral reflectance and fluorescence images in outdoor fields using ambient lighting or a pulsed laser (355 nm, respectively, for illumination purposes was designed, built, and tested. Components of the system include a semi-autonomous cart, a gated-intensified camera, a spectral adapter, a frequency-triple Nd:YAG (Neodymium-doped Yttrium Aluminium Garnet laser, and optics to convert the Gaussian laser beam into a line-illumination source. The front wheels of the cart are independently powered by stepper motors that support stepping or continuous motion. When stepping, a spreadsheet is used to program parameters of image sets to be acquired at each step. For example, the spreadsheet can be used to set delays before the start of image acquisitions, acquisition times, and laser attenuation. One possible use of this functionality would be to establish acquisition parameters to facilitate the measurement of fluorescence decay-curve characteristics. The laser and camera are mounted on an aluminum plate that allows the optics to be calibrated in a laboratory setting and then moved to the cart. The system was validated by acquiring images of fluorescence responses of spinach leaves and dairy manure.

New method of digital angiography

International Nuclear Information System (INIS)

Hashiya, Junichi; Korenaga, Takeo; Sakurai, Kenji; Sakai, Fumikazu; Kato, Hisatoyo; Takano, Masao.

1982-01-01

New experience of digital angiography using Fuji Intelligent Diagnostic X-ray System was reported. The system utilizes newly developed high sensitivity imaging plate in conjunction with computerized image processor instead of image intensifier-TV series, thus drastically improving image quality. Initial clinical trial was made in 46 cases including intravenous digital subtraction angiography and transcatheter digital arteriography. The advantages of this method were summerized as: 1. better resolution, 2. wider field size, 3. more sophisticated image manipulation program. (author)

Determination of alpha particle detection efficiency of an imaging plate (IP) detector

International Nuclear Information System (INIS)

Rahman, N.M; Iida, Takao; Yamazawa, Hiromi; Moriizumi, Jun

2006-01-01

In order to determine the detection efficiency of the imaging plate (IP) detector, the true radioactivity of the alpha particles, which sampled in the collection media, should be known. The true radioactivity could be accurately predicted with the help of the reference alpha spectrometer measurement. The detection efficiency calculated for the IP was estimated with the theoretical curve and the experimental data. It is assumed that the air sample contained the decay products of both 222 Rn and 220 Rn series, the most significant sources of alpha particles. The present study estimated the detection efficiency of the IP as 39.3% with an uncertainty of 2.9 that is well enough to confirm the future use of the IP as a radiation detector. Experimental materials and methods are described. (S.Y.)

An Expert System to Analyze Homogeneity in Fuel Element Plates for Research Reactors

International Nuclear Information System (INIS)

Tolosa, S.C.; Marajofsky, A.

2004-01-01

In the manufacturing control of Fuel Element Plates for Research Reactors, one of the problems to be addressed is how to determine the U-density homogeneity in a fuel plate and how to obtain qualitative and quantitative information in order to establish acceptance or rejection criteria for such, as well as carrying out the quality follow-up. This paper is aimed at developing computing software which implements an Unsupervised Competitive Learning Neural Network for the acknowledgment of regions belonging to a digitalized gray scale image. This program is applied to x-ray images. These images are generated when the x-ray beams go through a fuel plate of approximately 60 cm x 8 cm x 0.1 cm thick. A Nuclear Fuel Element for Research Reactors usually consists of 18 to 22 of these plates, positioned in parallel, in an arrangement of 8 x 7 cm. Carrying out the inspection of the digitalized x-ray image, the neural network detects regions with different luminous densities corresponding to U-densities in the fuel plate. This is used in quality control to detect failures and verify acceptance criteria depending on the homogeneity of the plate. This modality of inspection is important as it allows the performance of non-destructive measurements and the automatic generation of the map of U-relative densities of the fuel plate

An expert system to analyze homogeneity in fuel element plates for research reactors

International Nuclear Information System (INIS)

Cativa Tolosa, Sebastian; Marajofsky, Adolfo

2004-01-01

In the manufacturing control of Fuel Element Plates for Research Reactors, one of the problems to be addressed is how to determine the U-density homogeneity in a fuel plate and how to obtain qualitative and quantitative information in order to establish acceptance or rejection criteria for such, as well as carrying out the quality follow-up.This paper is aimed at developing computing software which implements an Unsupervised Competitive Learning Neural Network for the acknowledgment of regions belonging to a digitalized gray scale image. This program is applied to X-ray images. These images are generated when the X-ray beams go through a fuel plate of approximately 60 cm x 8 cm x 0.1 cm thick. A Nuclear Fuel Element for Research Reactors usually consists of 18 to 22 of these plates, positioned in parallel, in an arrangement of 8 x 7 cm. Carrying out the inspection of the digitalized X-ray image, the neural network detects regions with different luminous densities corresponding to U-densities in the fuel plate. This is used in quality control to detect failures and verify acceptance criteria depending on the homogeneity of the plate. This modality of inspection is important as it allows the performance of non-destructive measurements and the automatic generation of the map of U-relative densities of the fuel plate. (author)

Camera selection for real-time in vivo radiation treatment verification systems using Cherenkov imaging.

Science.gov (United States)

Andreozzi, Jacqueline M; Zhang, Rongxiao; Glaser, Adam K; Jarvis, Lesley A; Pogue, Brian W; Gladstone, David J

2015-02-01

To identify achievable camera performance and hardware needs in a clinical Cherenkov imaging system for real-time, in vivo monitoring of the surface beam profile on patients, as novel visual information, documentation, and possible treatment verification for clinicians. Complementary metal-oxide-semiconductor (CMOS), charge-coupled device (CCD), intensified charge-coupled device (ICCD), and electron multiplying-intensified charge coupled device (EM-ICCD) cameras were investigated to determine Cherenkov imaging performance in a clinical radiotherapy setting, with one emphasis on the maximum supportable frame rate. Where possible, the image intensifier was synchronized using a pulse signal from the Linac in order to image with room lighting conditions comparable to patient treatment scenarios. A solid water phantom irradiated with a 6 MV photon beam was imaged by the cameras to evaluate the maximum frame rate for adequate Cherenkov detection. Adequate detection was defined as an average electron count in the background-subtracted Cherenkov image region of interest in excess of 0.5% (327 counts) of the 16-bit maximum electron count value. Additionally, an ICCD and an EM-ICCD were each used clinically to image two patients undergoing whole-breast radiotherapy to compare clinical advantages and limitations of each system. Intensifier-coupled cameras were required for imaging Cherenkov emission on the phantom surface with ambient room lighting; standalone CMOS and CCD cameras were not viable. The EM-ICCD was able to collect images from a single Linac pulse delivering less than 0.05 cGy of dose at 30 frames/s (fps) and pixel resolution of 512 × 512, compared to an ICCD which was limited to 4.7 fps at 1024 × 1024 resolution. An intensifier with higher quantum efficiency at the entrance photocathode in the red wavelengths [30% quantum efficiency (QE) vs previous 19%] promises at least 8.6 fps at a resolution of 1024 × 1024 and lower monetary cost than the EM-ICCD. The

Instruments for radiation measurement in biosciences. Series 3. radioluminography. 11. Application of imaging plate in transmission electron microscopy

International Nuclear Information System (INIS)

Oikawa, Tetsuo

1999-01-01

Properties and application of the imaging plate (IP) in transmission electron microscopy (TEM) are reviewed. TEM has the resolution level of around 0.2 nm, which enables direct observation of molecules and atoms. In TEM, there are such recording systems as photographic film, TV camera, slow-scan CCD camera and IP. IP, to the electron beam, has the higher sensitivity than the film and has the broad dynamic range. Linearity between the input beam intensity and output signal is good, which makes it possible to record the image even with the small electron dose. Signal/noise ratio and detective quantum efficiency are important factors for precise image analysis. Fading phenomenon is a defect of IP, which weakens the signal output as time passing. For instance of application, IP is used for imaging of AgBr crystal fragile to strong electron beam required for the film. IP is necessary for quantitative analysis of TEM images and for the recently developed energy-filter TEM. (K.H.)

Industrial radiography with Ir-192 using computed radiographic technique

International Nuclear Information System (INIS)

Ngernvijit, Narippawaj; Punnachaiya, Suvit; Chankow, Nares; Sukbumperng, Ampai; Thong-Aram, Decho

2003-01-01

The aim of this research is to study the utilization of a low activity Ir-192 gamma source for industrial radiographic testing using the Computed Radiography (CR) system. Due to a photo-salbutamol Imaging Plate (I P) using in CR is much more radiation sensitive than a type II film with lead foil intensifying screen, the exposure time with CR can be significantly reduced. For short-lived gamma-ray source like Ir-192 source, the exposure time must be proportionally increased until it is not practical particularly for thick specimens. Generally, when the source decays to an activity of about 5 Ci or less, it will be returned to the manufacturer as a radioactive waste. In this research, the optimum conditions for radiography of a 20 mm thick welded steel sample with 2.4 Ci Ir-192 was investigated using the CR system with high resolution image plate, i.e. type Bas-SR of the Fuji Film Co. Ltd. The I P was sandwiched by a pair of 0.25 mm thick Pb intensifying sere en. Low energy scattered radiations was filtered by placing another Pb sheet with a thickness of 3 mm under the cassette. It was found that the CR image could give a contrast sensitivity of 2.5 % using only 3-minute exposure time which was comparable to the image taken by the type II film with Pb intensifying screen using the exposure time of 45 minutes

Measuring plate thickness using spatial local wavenumber filtering

International Nuclear Information System (INIS)

Kang, To; Han, Soon Woo; Park, Jin Ho; Lee, Jeong Han; Park, Gyu Hae; Jeon, Jun Young

2016-01-01

Corrosion on the surface of a structure can generate cracks or cause walls to thin. This can lead to fracturing, which can eventually lead to fatalities and property loss. In an effort to prevent this, laser imaging technology has been used over the last ten years to detect thin-plate structure, or relatively thin piping. The most common laser imaging was used to develop a new technology for inspecting and imaging a desired area in order to scan various structures for thin-plate structure and thin piping. However, this method builds images by measuring waves reflected from defects, and subsequently has a considerable time delay of a few milliseconds at each scanning point. In addition, the complexity of the system is high, due to additional required components, such as laser-focusing parts. This paper proposes a laser imaging method with an increased scanning speed, based on excitation and the measurement of standing waves in structures. The wavenumber of standing waves changes at sections with a geometrical discontinuity, such as thickness. Therefore, it is possible to detect defects in a structure by generating standing waves with a single frequency and scanning the waves at each point by with the laser scanning system. The proposed technique is demonstrated on a wall-thinned plate with a linear thickness variation

An Optimal Image-Based Method for Identification of Acoustic Emission (AE) Sources in Plate-Like Structures Using a Lead Zirconium Titanate (PZT) Sensor Array

Science.gov (United States)

Zhou, Li

2018-01-01

This paper proposes an innovative method for identifying the locations of multiple simultaneous acoustic emission (AE) events in plate-like structures from the view of image processing. By using a linear lead zirconium titanate (PZT) sensor array to record the AE wave signals, a reverse-time frequency-wavenumber (f-k) migration is employed to produce images displaying the locations of AE sources by back-propagating the AE waves. Lamb wave theory is included in the f-k migration to consider the dispersive property of the AE waves. Since the exact occurrence time of the AE events is usually unknown when recording the AE wave signals, a heuristic artificial bee colony (ABC) algorithm combined with an optimal criterion using minimum Shannon entropy is used to find the image with the identified AE source locations and occurrence time that mostly approximate the actual ones. Experimental studies on an aluminum plate with AE events simulated by PZT actuators are performed to validate the applicability and effectiveness of the proposed optimal image-based AE source identification method. PMID:29466310

An Optimal Image-Based Method for Identification of Acoustic Emission (AE) Sources in Plate-Like Structures Using a Lead Zirconium Titanate (PZT) Sensor Array.

Science.gov (United States)

Yan, Gang; Zhou, Li

2018-02-21

This paper proposes an innovative method for identifying the locations of multiple simultaneous acoustic emission (AE) events in plate-like structures from the view of image processing. By using a linear lead zirconium titanate (PZT) sensor array to record the AE wave signals, a reverse-time frequency-wavenumber (f-k) migration is employed to produce images displaying the locations of AE sources by back-propagating the AE waves. Lamb wave theory is included in the f-k migration to consider the dispersive property of the AE waves. Since the exact occurrence time of the AE events is usually unknown when recording the AE wave signals, a heuristic artificial bee colony (ABC) algorithm combined with an optimal criterion using minimum Shannon entropy is used to find the image with the identified AE source locations and occurrence time that mostly approximate the actual ones. Experimental studies on an aluminum plate with AE events simulated by PZT actuators are performed to validate the applicability and effectiveness of the proposed optimal image-based AE source identification method.

Spirit's View Beside 'Home Plate' on Sol 1823

Science.gov (United States)

2009-01-01

NASA's Mars Exploration Rover Spirit used its navigation camera to take the images that have been combined into this 180-degree view of the rover's surroundings during the 1,823rd Martian day, or sol, of Spirit's surface mission (Feb. 17, 2009). The center of the view is toward the south-southwest. The rover had driven 7 meters (23 feet) eastward earlier on Sol 1823, part of maneuvering to get Spirit into a favorable position for climbing onto the low plateau called 'Home Plate.' However, after two driving attempts with negligible progress during the following three sols, the rover team changed its strategy for getting to destinations south of Home Plate. The team decided to drive Spirit at least partway around Home Plate, instead of ascending the northern edge and taking a shorter route across the top of the plateau. Layered rocks forming part of the northern edge of Home Plate can be seen near the center of the image. Rover wheel tracks are visible at the lower edge. This view is presented as a cylindrical projection with geometric seam correction.

Simulation of the effects of coated material SEY property on output electron energy distribution and gain of microchannel plates

Energy Technology Data Exchange (ETDEWEB)

Chen, Lin [Key Laboratory of Ultra-fast Photoelectric Diagnostics Technology, Xi' an Institute of Optics and Precision Mechanics (XIOPM), Chinese Academy of Sciences (CAS), Xi' an 710119 (China); Graduate School of Chinese Academy of Sciences (CAS), Beijing 100049 (China); Xi' an Jiaotong University, Xi' an 710049 (China); Wang, Xingchao [North Night Vision Technology (NNVT) Co., Ltd., Nanjing 210110 (China); Tian, Jinshou, E-mail: tianjs@opt.ac.cn [Key Laboratory of Ultra-fast Photoelectric Diagnostics Technology, Xi' an Institute of Optics and Precision Mechanics (XIOPM), Chinese Academy of Sciences (CAS), Xi' an 710119 (China); Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006 (China); Liu, Chunliang [Xi' an Jiaotong University, Xi' an 710049 (China); Liu, Hulin [Key Laboratory of Ultra-fast Photoelectric Diagnostics Technology, Xi' an Institute of Optics and Precision Mechanics (XIOPM), Chinese Academy of Sciences (CAS), Xi' an 710119 (China); Chen, Ping [Key Laboratory of Ultra-fast Photoelectric Diagnostics Technology, Xi' an Institute of Optics and Precision Mechanics (XIOPM), Chinese Academy of Sciences (CAS), Xi' an 710119 (China); Graduate School of Chinese Academy of Sciences (CAS), Beijing 100049 (China); Wei, Yonglin; Sai, Xiaofeng [Key Laboratory of Ultra-fast Photoelectric Diagnostics Technology, Xi' an Institute of Optics and Precision Mechanics (XIOPM), Chinese Academy of Sciences (CAS), Xi' an 710119 (China); Sun, Jianning; Si, Shuguang [North Night Vision Technology (NNVT) Co., Ltd., Nanjing 210110 (China); Wang, Xing; Lu, Yu [Key Laboratory of Ultra-fast Photoelectric Diagnostics Technology, Xi' an Institute of Optics and Precision Mechanics (XIOPM), Chinese Academy of Sciences (CAS), Xi' an 710119 (China); and others

2016-12-21

To obtain a high spatial resolution of a image intensifier based on microchannel plate (MCP), the long tail in the exit energy distribution of the output electrons (EDOE) is undesirable. The existing solution is increasing the penetration depth of the MCP output electrode, which will result in a serious gain reduction. Coating the MCP output electrode with efficient secondary electron yield (SEY) materials is supposed to be an effective approach to suppress the unfavorable tail component in the EDOE without negative effects on the gain. In our work, a three-dimensional MCP single channel model is developed in CST STUDIO SUITE to systematically investigate the dependences of the EDOE and the gain on the SEY property of the coated material, based on the Finite Integral Technique and Monte Carlo method. The results show that besides the high SEY of the coated material, the low incident energy corresponding to the peak SEY is another essential element affecting the electron yield in the final stage of multiplication and suppressing the output energy spread.

Phosphor plate mammography: contrast studies and clinical experience

International Nuclear Information System (INIS)

Chang, C.H.J.; Martin, N.L.; Templeton, A.W.; Cook, L.T.; Harrison, L.A.; McFadden, M.A.; Dwyer, S.J. III; Spicer, J.; Crystal, J.M.

1992-01-01

Mammography and accurate microcalcification detection require very good spatial resolution. We have compared the diagnostic capabilities of reduced-exposure, third-generation, 5 cycles/mm computed radiography (CR) phosphor plates with conventional screen-film in 67 patients. No difference in diagnostic accuracy was detected. The digital characteristics of storage phosphor plates erabled us to study the relationship between contrast and spatial resolution. We developed a computer program to identify a single 100 μm pixel in a digital image and assign various gray levels to that pixel. Using this model, we determined that, for our 5 cycles/mm CR system, the imaged contrast of a 100 μm object was 62% of the original contrast. Current 5 cycles/mm phosphor plate systems cannot adequately detect microcalcifications that approximate 100 μm or smaller unless a magnification technique is used. (orig.)

A Malaysian Vehicle License Plate Localization and Recognition System

Directory of Open Access Journals (Sweden)

Ganapathy Velappa

2008-02-01

Full Text Available Technological intelligence is a highly sought after commodity even in traffic-based systems. These intelligent systems do not only help in traffic monitoring but also in commuter safety, law enforcement and commercial applications. In this paper, a license plate localization and recognition system for vehicles in Malaysia is proposed. This system is developed based on digital images and can be easily applied to commercial car park systems for the use of documenting access of parking services, secure usage of parking houses and also to prevent car theft issues. The proposed license plate localization algorithm is based on a combination of morphological processes with a modified Hough Transform approach and the recognition of the license plates is achieved by the implementation of the feed-forward backpropagation artificial neural network. Experimental results show an average of 95% successful license plate localization and recognition in a total of 589 images captured from a complex outdoor environment.

Study of imaging plate detector sensitivity to 5-18 MeV electrons

Energy Technology Data Exchange (ETDEWEB)

Boutoux, G., E-mail: boutoux@celia.u-bordeaux1.fr; Rabhi, N.; Batani, D.; Ducret, J.-E. [Univ. de Bordeaux, CNRS, CEA, CELIA (Centre Lasers Intenses et Applications), UMR 5107, F-33405 Talence (France); Binet, A.; Nègre, J.-P.; Reverdin, C.; Thfoin, I. [CEA DAM DIF, F-91297 Arpajon (France); Jakubowska, K. [Institute of Plasma Physics and Laser Microfusion, Hery Street 23, 01-497 Warsaw (Poland)

2015-11-15

Imaging plates (IPs) are commonly used as passive detectors in laser-plasma experiments. We calibrated at the ELSA electron beam facility (CEA DIF) the five different available types of IPs (namely, MS-SR-TR-MP-ND) to electrons from 5 to 18 MeV. In the context of diagnostic development for the PETawatt Aquitaine Laser (PETAL), we investigated the use of stacks of IP in order to increase the detection efficiency and get detection response independent from the neighboring materials such as X-ray shielding and detector supports. We also measured fading functions in the time range from a few minutes up to a few days. Finally, our results are systematically compared to GEANT4 simulations in order to provide a complete study of the IP response to electrons over the energy range relevant for PETAL experiments.

Calibration of imaging plates to electrons between 40 and 180 MeV

International Nuclear Information System (INIS)

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

2016-01-01

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.

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.

Iodine filter imaging system for subtraction angiography using synchrotron radiation

Science.gov (United States)

Umetani, K.; Ueda, K.; Takeda, T.; Itai, Y.; Akisada, M.; Nakajima, T.

1993-11-01

A new type of real-time imaging system was developed for transvenous coronary angiography. A combination of an iodine filter and a single energy broad-bandwidth X-ray produces two-energy images for the iodine K-edge subtraction technique. X-ray images are sequentially converted to visible images by an X-ray image intensifier. By synchronizing the timing of the movement of the iodine filter into and out of the X-ray beam, two output images of the image intensifier are focused side by side on the photoconductive layer of a camera tube by an oscillating mirror. Both images are read out by electron beam scanning of a 1050-scanning-line video camera within a camera frame time of 66.7 ms. One hundred ninety two pairs of iodine-filtered and non-iodine-filtered images are stored in the frame memory at a rate of 15 pairs/s. In vivo subtracted images of coronary arteries in dogs were obtained in the form of motion pictures.

X-ray intensifying screens

International Nuclear Information System (INIS)

Luckey, G.W.; DeBoer, C.D.

1982-01-01

An x-ray intensifying screen comprises a support which has a luminescent composition comprising an isotropic phosphor and a polymer having an index of refraction within 0.02 of that of the phosphor over at least 80 percent of its emission spectrum. The support has an index of refraction up to or equal to 0.05 units higher than that of the phosphor and has a reflection optical density of at least 1.7 to light emitted by the phosphor. A preferred luminescent composition comprises Kl:Tl, Rbl:Tl at BaSrFCl:Eu mixed with two monomers such as 1-naphthylmethylmethacrylate, S(1-naphthylmethyl) thioacrylate, 1-bromo-2-naphthylacrylate, and benzyl methacrylate, coated on black anodised Al and polymerised in situ. The ratio of monomers is adjusted to give the desired refractive index. Other phosphors, polymers and supports are specified together with the preparation of the monomers and polymers. (author)

Evaluation of mammographic X-ray beams using a phosphor plate

Energy Technology Data Exchange (ETDEWEB)

Bustos F, M.; Prata M, A., E-mail: mbustos@ufmg.br [Universidade Federal de Minas Gerais, Departamento de Engenharia Nuclear, Av. Pte. Antonio Carlos 6627, 31270-901 Pampulha, Belo Horizonte, Minas Gerais (Brazil)

2016-10-15

Currently, breast cancer is the second type of cancer more with higher overall incidence recorded in 2015, more than 57,000 new cases according to the National Cancer Institute of Brazil Mammography is now one of the imaging technique most widely used worldwide for the early diagnosis of breast cancer. The computed radiography (Cr) plates are used to obtain digital radiographs, and are widely used for digital mammogram production. This study aims to evaluate the variation response in the exposure of a Cr plate in mammography unit. For this study a mammography device model Graph A F Mammo, made by Vmi and a Cr plate, model Regius, were used for mammography. Experiments were made with two X-ray beams of 20 and 25 kV. Successive exposures of the Cr plate were made in a time range time from 0.5 to 2.5 s., to obtain unprocessed images .raw and subsequently make the measurement of time, air kerma and air kerma rate using a Ray Safe Xi meter. Five measurements for each exposure time were performed and the images were analyzed using the Image J software. A matrix of 21 x 21 pixels was selected in the central region of each image to obtain the intensity value, in grey scale, for each exposure time. From these data, a correlation of the degree of darkening was made with time and the air kerma. The behavior of the curves corresponding to the intensity average values of central pixels in relation to the exposure time and air kerma are similar for both voltages,showing an initially linear behavior and then a plate saturation region, whichever occurs first at the greatest value of the applied voltage. (Author)

Evaluation of mammographic X-ray beams using a phosphor plate

International Nuclear Information System (INIS)

Bustos F, M.; Prata M, A.

2016-10-01

Currently, breast cancer is the second type of cancer more with higher overall incidence recorded in 2015, more than 57,000 new cases according to the National Cancer Institute of Brazil Mammography is now one of the imaging technique most widely used worldwide for the early diagnosis of breast cancer. The computed radiography (Cr) plates are used to obtain digital radiographs, and are widely used for digital mammogram production. This study aims to evaluate the variation response in the exposure of a Cr plate in mammography unit. For this study a mammography device model Graph A F Mammo, made by Vmi and a Cr plate, model Regius, were used for mammography. Experiments were made with two X-ray beams of 20 and 25 kV. Successive exposures of the Cr plate were made in a time range time from 0.5 to 2.5 s., to obtain unprocessed images .raw and subsequently make the measurement of time, air kerma and air kerma rate using a Ray Safe Xi meter. Five measurements for each exposure time were performed and the images were analyzed using the Image J software. A matrix of 21 x 21 pixels was selected in the central region of each image to obtain the intensity value, in grey scale, for each exposure time. From these data, a correlation of the degree of darkening was made with time and the air kerma. The behavior of the curves corresponding to the intensity average values of central pixels in relation to the exposure time and air kerma are similar for both voltages,showing an initially linear behavior and then a plate saturation region, whichever occurs first at the greatest value of the applied voltage. (Author)

Quality assurance in diagnostic radiology - assessing the fluoroscopic image quality

International Nuclear Information System (INIS)

Tabakov, S.

1995-01-01

The X-ray fluoroscopic image has a considerably lower resolution than the radiographic one. This requires a careful quality control aiming at optimal use of the fluoroscopic equipment. The basic procedures for image quality assessment of Image Intensifier/TV image are described. Test objects from Leeds University (UK) are used as prototypes. The results from examining 50 various fluoroscopic devices are shown. Their limiting spatial resolution varies between 0.8 lp/mm (at maximum II field size) and 2.24 lp/mm (at minimum field size). The mean value of the limiting spatial resolution for a 23 cm Image Intensifier is about 1.24 lp/mm. The mean limits of variation of the contrast/detail diagram for various fluoroscopic equipment are graphically expressed. 14 refs., 1 fig. (author)

Digital cardiovascular imaging

International Nuclear Information System (INIS)

Myerowitz, P.D.; Mistretta, C.A.; Shaw, C.-G.; Van Lysel, M.S.; Swanson, D.K.; Lasser, T.A.; Dhanani, S.P.; Zarnstorff, W.C.; Vander Ark, C.R.; Dobbins, J.T.; Peppler, W.W.; Crummy, A.B.

1982-01-01

The authors have previously reported on real time digital fluoroscopic subtraction techniques developed in the laboratory during the past 10 years. This paper outlines basic apparatus configuration and imaging modes used for preliminary studies involving visualization of the canine and human heart. All of the techniques involve the use of real time digital subtraction processing of data from an image intensified television fluoroscopy system. Based on the configuration of the digital processing equipment a number of different imaging modalities are possible. A brief description of the apparatus and these imaging modes is given. (Auth.)

The design and imaging characteristics of dynamic, solid-state, flat-panel x-ray image detectors for digital fluoroscopy and fluorography

International Nuclear Information System (INIS)

Cowen, A.R.; Davies, A.G.; Sivananthan, M.U.

2008-01-01

Dynamic, flat-panel, solid-state, x-ray image detectors for use in digital fluoroscopy and fluorography emerged at the turn of the millennium. This new generation of dynamic detectors utilize a thin layer of x-ray absorptive material superimposed upon an electronic active matrix array fabricated in a film of hydrogenated amorphous silicon (a-Si:H). Dynamic solid-state detectors come in two basic designs, the indirect-conversion (x-ray scintillator based) and the direct-conversion (x-ray photoconductor based). This review explains the underlying principles and enabling technologies associated with these detector designs, and evaluates their physical imaging characteristics, comparing their performance against the long established x-ray image intensifier television (TV) system. Solid-state detectors afford a number of physical imaging benefits compared with the latter. These include zero geometrical distortion and vignetting, immunity from blooming at exposure highlights and negligible contrast loss (due to internal scatter). They also exhibit a wider dynamic range and maintain higher spatial resolution when imaging over larger fields of view. The detective quantum efficiency of indirect-conversion, dynamic, solid-state detectors is superior to that of both x-ray image intensifier TV systems and direct-conversion detectors. Dynamic solid-state detectors are playing a burgeoning role in fluoroscopy-guided diagnosis and intervention, leading to the displacement of x-ray image intensifier TV-based systems. Future trends in dynamic, solid-state, digital fluoroscopy detectors are also briefly considered. These include the growth in associated three-dimensional (3D) visualization techniques and potential improvements in dynamic detector design

An autoradiographical method using an imaging plate for the analyses of plutonium contamination in a plutonium handling facility

International Nuclear Information System (INIS)

Takasaki, Koji; Sagawa, Naoki; Kurosawa, Shigeyuki; Mizuniwa, Harumi

2011-01-01

An autoradiographical method using an imaging plate (IP) was developed to analyze plutonium contamination in a plutonium handling facility. The IPs were exposed to ten specimens having a single plutonium particle. Photostimulated luminescence (PSL) images of the specimens were taken using a laser scanning machine. One relatively large spot induced by α-radioactivity from plutonium was observed in each PSL image. The plutonium-induced spots were discriminated by a threshold derived from background and the size of the spot. A good relationship between the PSL intensities of the spots and α-radioactivities measured using a radiation counter was obtained by least-square fitting, taking the fading effect into consideration. This method was applied to workplace monitoring in an actual uranium-plutonium mixed oxide (MOX) fuel fabrication facility. Plutonium contaminations were analyzed in ten other specimens having more than two plutonium spots. The α-radioactivities of plutonium contamination were derived from the PSL images and their relative errors were evaluated from exposure time. (author)

X-ray microscopy with high resolution zone plates -- Recent developments

International Nuclear Information System (INIS)

Schneider, G.; Wilhein, T.; Niemann, B.; Guttmann, P.

1995-01-01

In order to expand the applications of X-ray microscopy, developments in the fields of zone plate technology, specimen preparation and imaging techniques have been made. A new cross-linked polymer chain electron beam resist allows to record zone plate pattern down to 19 nm outermost zone width. High resolution zone plates in germanium with outermost zone widths down to 19 nm have been developed. In addition, phase zone plates in nickel down to 30 nm zone width have been made by electroplating. In order to enhance the image contrast for weak absorbing objects, the phase contrast method for X-ray microscopy was developed and implemented on the Goettingen X-ray microscope at BESSY. The effects of X-ray absorption on the structure of biological specimen limits the maximum applicable radiation dose and therefore the achievable signal to noise ratio for an artifact-free X-ray image. To improve the stability especially of biological specimen, a cryogenic object chamber has been developed and tested. It turns out that at the operating temperature T ≤ 130 K unfixed biological specimen can be exposed to a radiation dose of 10 9 --10 10 Gy without any observable structural changes. A multiple-angle viewing stage allows to take stereoscopic images with the X-ray microscope, giving a 3D-impression of the object

Detective quantum efficiency of medical x-ray image intensifiers

CSIR Research Space (South Africa)

Thirlwall, JT

1998-11-01

Full Text Available -energyphotons,thevariancesofstagesafterthe photoemitterhavenegligiblein?uenc eonthevalueofBand thesehavebeenomittedfromthecalculationsreportedhere. Ithasbeenpointedout,however,11 thatwithanintensex-ray input,theXRIIoutputsignalmayhavetobeattenuated,for examplewithanirisintheopticalcomponents....W.ArndtandD.J.Gilmore,J.Appl.Crystallogr.12,1~1979!. 9 M.Stanton,W.Phillips,Y.Li,andK.Kalata,J.Appl.Crystallogr.25, 638~1992!. 10 W.KuhlandJ.E.Schrijvers,Medicamundi22,6~1977!. 11 A.Makovski,MedicalImagingSystems~Prentice?Hall,Englewood Cliffs,NJ,1983!,p.87. 12 S...

Image quality in digital radiography

International Nuclear Information System (INIS)

Kuhn, H.

1986-01-01

The contribution deals with the potentials of digital radiography and critically evaluates the advantages of drawbacks of the image intensifier-tv-digital system; digitalisation of the X-ray film and scanning of luminescent storage foils. The evaluation is done in comparison with the image quality of the traditional, large-size X-ray picture. (orig.) [de

Dynamics analysis of extraction of manganese intensified by electric field

Science.gov (United States)

Ma, Wenrui; Tao, Changyuan; Li, Huizhan; Liu, Zuohua; Liu, Renlong

2018-06-01

In this study, a process reinforcement technology for leaching process of pyrolusite was developed. The electric field was introduced to decrease reaction temperature and improve the leaching rate of pyrolusite. The mechanisms of electric field intensifying leaching process of pyrolusite were investigated through X-ray diffraction (XRD), and Brunauer Emmett Teller (BET) in detail. The results showed that the electric field could decrease obviously the apparent activation energy of leaching process of pyrolusite. The apparent activation energy of the leaching of pyrolusite intensified by electric field was calculated to be 53.76 kJ.mol-1. In addition, the leaching efficiency of manganese was effectively increased by 10% to 20% than that without electric field under the same conditions. This was because that the electron conduit between Fe (II)/Fe (III) and pyrite was dredged effectively by electric field.

Crustal Structure of the Tengchong Intra-plate Volcanic Area

Science.gov (United States)

Qian, Rongyi; Tong, Vincent C. H.

2015-09-01

We here provide an overview of our current understanding of the crustal structure of Tengchong in southwest China, a key intra-plate volcanic area along the Himalayan geothermal belt. Given that there is hitherto a lack of information about the near-surface structure of intra-plate volcanic areas, we present the first seismic reflection and velocity constraints on the shallow crust between intra-plate volcanoes. Our near-surface seismic images reveal the existence of dome-shaped seismic reflectors (DSRs) in the shallow crust between intra-plate volcanic clusters in Tengchong. The two DSRs are both ~2 km wide, and the shallowest parts of the DSRs are found at the depth of 200-300 m. The velocity model shows that the shallow low-velocity layer (<4 km/s) is anomalously thick (~1 km) in the region where the DSRs are observed. The presence of DSRs indicates significant levels of intra-plate magmatism beneath the along-axis gap separating two volcano clusters. Along-axis gaps between volcano clusters are therefore not necessarily an indicator of lower levels of magmatism. The seismic images obtained in this technically challenging area for controlled-source seismology allow us to conclude that shallow crustal structures are crucial for understanding the along-axis variations of magmatism and hydrothermal activities in intra-plate volcanic areas.

Exact thermal representation of multilayer rectangular structures by infinite plate structures using the method of images

Science.gov (United States)

Palisoc, Arthur L.; Lee, Chin C.

1988-12-01

Using the method of images and the analytical temperature solution to the multilayer infinite plate structure, the thermal profile over finite rectangular multilayer integrated circuit devices can be calculated exactly. The advantage of using the image method lies in the enhanced capability of arriving at an analytical solution for structures where analytical solutions do not apparently exist, e.g., circular or arbitrarily oriented rectangular sources over multilayered rectangular structures. The new approach results in large savings in computer CPU time especially for small sources over large substrates. The method also finds very important applications to integrated circuit devices with heat dissipating elements close to the edge boundaries. Results from two examples indicate that the edge boundaries of a device may also be utilized to remove heat from it. This additional heat removing capability should have important applications in high power devices.

The iQID camera: An ionizing-radiation quantum imaging detector

Energy Technology Data Exchange (ETDEWEB)

Miller, Brian W., E-mail: brian.miller@pnnl.gov [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); College of Optical Sciences, The University of Arizona, Tucson, AZ 85719 (United States); Gregory, Stephanie J.; Fuller, Erin S. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Barrett, Harrison H.; Bradford Barber, H.; Furenlid, Lars R. [Center for Gamma-Ray Imaging, The University of Arizona, Tucson, AZ 85719 (United States); College of Optical Sciences, The University of Arizona, Tucson, AZ 85719 (United States)

2014-12-11

We have developed and tested a novel, ionizing-radiation Quantum Imaging Detector (iQID). This scintillation-based detector was originally developed as a high-resolution gamma-ray imager, called BazookaSPECT, for use in single-photon emission computed tomography (SPECT). Recently, we have investigated the detector's response and imaging potential with other forms of ionizing radiation including alpha, neutron, beta, and fission fragment particles. The confirmed response to this broad range of ionizing radiation has prompted its new title. The principle operation of the iQID camera involves coupling a scintillator to an image intensifier. The scintillation light generated by particle interactions is optically amplified by the intensifier and then re-imaged onto a CCD/CMOS camera sensor. The intensifier provides sufficient optical gain that practically any CCD/CMOS camera can be used to image ionizing radiation. The spatial location and energy of individual particles are estimated on an event-by-event basis in real time using image analysis algorithms on high-performance graphics processing hardware. Distinguishing features of the iQID camera include portability, large active areas, excellent detection efficiency for charged particles, and high spatial resolution (tens of microns). Although modest, iQID has energy resolution that is sufficient to discriminate between particles. Additionally, spatial features of individual events can be used for particle discrimination. An important iQID imaging application that has recently been developed is real-time, single-particle digital autoradiography. We present the latest results and discuss potential applications.

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

International Nuclear Information System (INIS)

Ohuchi, Hiroko; Kondo, Yasuhiro

2010-01-01

The absorption spectra of deep centers in an imaging plate (IP) made of BaFBr 0:85 I 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.

License plate recognition using DTCNNs

NARCIS (Netherlands)

ter Brugge, M.H; Stevens, J.H; Nijhuis, J.A G; Spaanenburg, L; Tavsanonoglu, V

1998-01-01

Automatic license plate recognition requires a series of complex image processing steps. For practical use, the amount of data to he processed must be minimized early on. This paper shows that the computationally most intensive steps can be realized by DTCNNs. Moreover; high-level operations like

Landmark-based elastic registration using approximating thin-plate splines.

Science.gov (United States)

Rohr, K; Stiehl, H S; Sprengel, R; Buzug, T M; Weese, J; Kuhn, M H

2001-06-01

We consider elastic image registration based on a set of corresponding anatomical point landmarks and approximating thin-plate splines. This approach is an extension of the original interpolating thin-plate spline approach and allows to take into account landmark localization errors. The extension is important for clinical applications since landmark extraction is always prone to error. Our approach is based on a minimizing functional and can cope with isotropic as well as anisotropic landmark errors. In particular, in the latter case it is possible to include different types of landmarks, e.g., unique point landmarks as well as arbitrary edge points. Also, the scheme is general with respect to the image dimension and the order of smoothness of the underlying functional. Optimal affine transformations as well as interpolating thin-plate splines are special cases of this scheme. To localize landmarks we use a semi-automatic approach which is based on three-dimensional (3-D) differential operators. Experimental results are presented for two-dimensional as well as 3-D tomographic images of the human brain.

Multiscale hydrodynamic investigation to intensify the biogas production in upflow anaerobic reactors.

Science.gov (United States)

Jiang, Jiankai; Wu, Jing; Zhang, Jinbai; Poncin, Souhila; Li, Huai Z

2014-03-01

Hydrodynamics plays a main role for the performance of an anaerobic reactor involving three phases: wastewater, sludge granules and biogas bubbles. The present work was focused on an original approach to investigate the hydrodynamics at different scales and then to intensify the performance of such complex reactors. The experiments were carried out respectively in a 3D reactor at macroscale, a 2D reactor at mesoscale and a 1D anaerobic reactor at microscale. A Particle Image Velocimetry (PIV), a micro-PIV and a high-speed camera were employed to quantify the liquid flow fields and the relative motion between sludge granules and bubbles. Shear rates exerted on sludge granules were quantified from liquid flow fields. The optimal biogas production is obtained at mean shear rate varying from 28 to 48s(-1), which is controlled by two antagonistic mechanisms. The multiscale approach demonstrates pertinent mechanisms proper to each scale and allows a better understanding of such reactors. Copyright © 2014 Elsevier Ltd. All rights reserved.

First results of astrometric and photometric processing of scanned plates DLFA MAO NAS of Ukraine

Science.gov (United States)

Shatokhina, S.; Andruk, V.; Yatsenko, A.

2011-02-01

In the paper the first estimation of astrometric and photometric results of digitization of images on plates of Double Long Focus Astrograph (DLFA) was made. The digitization of plates was carried out with the scanner Microtek ScanMaker 9800XL TMA. For image processing the package LINUX/MIDAS/ROMAFOT was used. For selected plates DLFA mean square errors for equatorial coordinates (in a system of TYCHO-2 catalogue) and stellar magnitudes (in the Johnson B-system) per one image are 0.06" and 0.13m. The errors are of random nature and there are no systematic dependences on coordinates, magnitudes and colour of stars. The comparison of obtained results with that of earlier plate measurements obtained with complex PARSEC was made.

Clinical multi-colour fluorescence imaging of malignant tumours - initial experience

International Nuclear Information System (INIS)

Svanberg, K.; Wang, I.; Montan, S.; Andersson-Engels, S.; Svanberg, S.; Lund Inst. of Technology

1998-01-01

The purpose of this study was to present a new technique for non-invasive tumour detection based on tissue fluorescence imaging. A clinically adapted multi-colour fluorescence system was employed in the real-time imaging of malignant tumours of the skin, breast, head and neck region, and urinary bladder. Tumour detection was based on the contrast displayed in fluorescence between normal and malignant tissue, related to the selective uptake of tumour-marking agents and natural chromophore differences between various tissues. In order to demarcate basal cell carcinomas of the skin, ALA was applied topically 4-6 h before the fluorescence investigation. For urinary bladder tumour visualisation, ALA was instilled into the bladder 1-2 h prior to the study. Malignant and premalignant lesions in the head and neck region were imaged after i.v. injection of HPD (Photofrin). The tumour imaging system was coupled to an endoscope. Fluorescence light emission from the tissue surface was induced with 100-ns-long optical pulses at 390 nm, generated from a frequency-doubled alexandrite laser. With the use of special image-splitting optics, the tumour fluorescence, intensified in a micro-channel plate, was imaged in 3 selected wavelength bands. These 3 images were processed together to form a new optimised-contrast image of the tumour. This image, updated at a rate of about 3 frames/s was mixed with a normal colour video image of the tissue. A clear demarcation from normal surrounding tissue was found during in vivo measurements of superficial bladder carcinoma, basal cell carcinoma of the skin, and leukoplakia with dysplasia of the lip, and in vitro investigations of resected breast cancer. (orig./MG)

Selection of Rational Heat Transfer Intensifiers in the Heat Exchanger

Directory of Open Access Journals (Sweden)

S. A. Burtsev

2016-01-01

Full Text Available The paper considers the applicability of different types of heat transfer intensifiers in the heat exchange equipment. A review of the experimental and numerical works devoted to the intensification of the dimpled surface, surfaces with pins and internally ribbed surface were presented and data on the thermal-hydraulic characteristics of these surfaces were given. We obtained variation of thermal-hydraulic efficiency criteria for 4 different objective functions and 15 options for the intensification of heat transfer. This makes it possible to evaluate the advantages of the various heat transfer intensifiers. These equations show influence of thermal and hydraulic characteristics of the heat transfer intensifiers (the values of the relative heat transfer and drag coefficients on the basic parameters of the shell-and-tube heat exchanger: the number and length of the tubes, the volume of the heat exchanger matrix, the coolant velocity in the heat exchanger matrix, coolant flow rate, power to pump coolant (or pressure drop, the amount of heat transferred, as well as the average logarithmic temperature difference. The paper gives an example to compare two promising heat transfer intensifiers in the tubes and shows that choosing the required efficiency criterion to search for optimal heat exchanger geometry is of importance. Analysis is performed to show that a dimpled surface will improve the effectiveness of the heat exchanger despite the relatively small value of the heat transfer intensification, while a significant increase in drag of other heat transfer enhancers negatively affects their thermalhydraulic efficiency. For example, when comparing the target functions of reducing the heat exchanger volume, the data suggest that application of dimpled surfaces in various fields of technology is possible. But there are also certain surfaces that can reduce the parameters of a heat exchanger. It is shown that further work development should be aimed at

Intensified multifactorial intervention and cardiovascular outcome in type 2 diabetes

DEFF Research Database (Denmark)

Pedersen, Oluf; Gaede, Peter

2003-01-01

We recently published the results of the Steno-2 study, which evaluated the benefits of intensified integrated behavior modification and targeted polypharmacy. The results provide abundant evidence that an ambitious treatment strategy is superior to a conventional one. The study involved 160 high...

Forces Between a Permanent Magnet and a Soft Magnetic Plate

DEFF Research Database (Denmark)

Beleggia, Marco; Vokoun, David; De Graef, Marc

2012-01-01

Forces between a hard/permanent magnet of arbitrary shape and an ideally soft magnetic plate in close proximity are derived analytically from the image method applied to magnetostatics. We found that the contact force, defined as the force required to detach the hard magnet from the plate, coinci...

Visual illusions and plate design: the effects of plate rim widths and rim coloring on perceived food portion size.

Science.gov (United States)

McClain, A D; van den Bos, W; Matheson, D; Desai, M; McClure, S M; Robinson, T N

2014-05-01

The Delboeuf Illusion affects perceptions of the relative sizes of concentric shapes. This study was designed to extend research on the application of the Delboeuf illusion to food on a plate by testing whether a plate's rim width and coloring influence perceptual bias to affect perceived food portion size. Within-subjects experimental design. Experiment 1 tested the effect of rim width on perceived food portion size. Experiment 2 tested the effect of rim coloring on perceived food portion size. In both experiments, participants observed a series of photographic images of paired, side-by-side plates varying in designs and amounts of food. From each pair, participants were asked to select the plate that contained more food. Multilevel logistic regression examined the effects of rim width and coloring on perceived food portion size. Experiment 1: participants overestimated the diameter of food portions by 5% and the visual area of food portions by 10% on plates with wider rims compared with plates with very thin rims (Pfood portion sizes. Experiment 2: participants overestimated the diameter of food portions by 1.5% and the visual area of food portions by 3% on plates with rim coloring compared with plates with no coloring (P=0.01). The effect of rim coloring was greater with smaller food portion sizes. The Delboeuf illusion applies to food on a plate. Participants overestimated food portion size on plates with wider and colored rims. These findings may help design plates to influence perceptions of food portion sizes.

Modeling particulate removal in plate-plate and wire-plate electrostatic precipitators

Directory of Open Access Journals (Sweden)

S Ramechecandane

2016-09-01

Full Text Available The present study is concerned with the modeling of electrically charged particles in a model plate-plate and a single wire-plate electrostatic precipitator (ESP. The particle concentration distributions for both a plate-plate and a wire-plate ESP are calculated using a modified drift flux model. Numerical investigations are performed using the modified drift flux model for particle number concentration, in addition to the RNG k - ε model for the mean turbulent flow field and the Poisson equation for the electric field. The proposed model and the outlined methodology for coupling the flow field, electric field, charging kinetics and particle concentration is applied to two model precipitators that are truly representative of a wide class of commercialized ESPs. The present investigation is quite different from the earlier studies as it does not make assumptions like a homogeneous electric field or an infinite turbulent diffusivity. The electric field calculated is a strong function of position and controls the migration velocity of particles. Hence, the proposed model can be implemented in a flow solver to obtain a full-fledged solution for any kind of ESP with no limitations on the particle number concentration, as encountered in a Lagrangian approach. The effect of turbulent diffusivity on particle number concentration in a plate-plate ESP is investigated in detail and the results obtained are compared with available experimental data. Similarly, the effect of particle size/diameter and applied electric potential on the accumulative collection performance in the case of a wire-plate ESP is studied and the results obtained are compared with available numerical data. The numerical results obtained using the modified drift flux model for both the plate-plate and wire-plate ESP are in close agreement with available experimental and numerical data.

Perceptual evaluation of different image fusion schemes

NARCIS (Netherlands)

Toet, A.; IJspeert, J.K.

2001-01-01

Human perceptual performance was tested with images of nighttime outdoor scenes. The scenes were registered both with a dual band (visual and near infrared) image intensified low-light CCD camera (DII) and with a thermal middle wavelength band (3-5 μm) infrared (IR) camera. Fused imagery was

2-Mercaptobenzimidazole, 2-Mercaptobenzothiazole, and Thioglycolic Acid in an Electroless Nickel-Plating Bath

OpenAIRE

Ahmet Ozan Gezerman; Burcu Didem Çorbacıoğlu

2015-01-01

The use of three different materials, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, and thioglycolic acid, was investigated to improve the performance of electroless nickel-plating baths. By changing the concentrations of these materials, sample plates were coated. Optical microscope images were obtained by selecting representative coated plates. From the results of the investigations, the effects of these materials on electroless nickel plating were observed, and the most appropriate amo...

Multiframe Superresolution of Vehicle License Plates Based on Distribution Estimation Approach

Directory of Open Access Journals (Sweden)

Renchao Jin

2016-01-01

Full Text Available Low-resolution (LR license plate images or videos are often captured in the practical applications. In this paper, a distribution estimation based superresolution (SR algorithm is proposed to reconstruct the license plate image. Different from the previous work, here, the high-resolution (HR image is estimated via the obtained posterior probability distribution by using the variational Bayesian framework. To regularize the estimated HR image, a feature-specific prior model is proposed by considering the most significant characteristic of license plate images; that is, the target has high contrast with the background. In order to assure the success of the SR reconstruction, the models representing smoothness constraints on images are also used to regularize the estimated HR image with the proposed feature-specific prior model. We show by way of experiments, under challenging blur with size 7 × 7 and zero-mean Gaussian white noise with variances 0.2 and 0.5, respectively, that the proposed method could achieve the peak signal-to-noise ratio (PSNR of 22.69 dB and the structural similarity (SSIM of 0.9022 under the noise with variance 0.2 and the PSNR of 19.89 dB and the SSIM of 0.8582 even under the noise with variance 0.5, which are 1.84 dB and 0.04 improvements in comparison with other methods.

Developments in microchannel plate detectors for imaging x-ray astronomy

International Nuclear Information System (INIS)

Fraser, G.W.; Whiteley, M.J.; Pearson, J.F.

1985-01-01

The authors present new results in four areas of microchannel plate (MCP) X-ray detector operation. The performance in pulse counting mode of MCPs with 8 micron channel diameters is reported. The effects on MCP quantum detection efficiency and energy discrimination of multiple CsI coatings are described. A new mode of operation of two-stage multipliers is evaluated. Replacing the conventional electron-accelerating inter-plate potential difference by a retarding field is shown to result in definite advantages with regard to X-ray energy discrimination and detector lifetime. The source of the MCP internal background is discussed

Detection of License Plate using Sliding Window, Histogram of Oriented Gradient, and Support Vector Machines Method

Science.gov (United States)

Astawa, INGA; Gusti Ngurah Bagus Caturbawa, I.; Made Sajayasa, I.; Dwi Suta Atmaja, I. Made Ari

2018-01-01

The license plate recognition usually used as part of system such as parking system. License plate detection considered as the most important step in the license plate recognition system. We propose methods that can be used to detect the vehicle plate on mobile phone. In this paper, we used Sliding Window, Histogram of Oriented Gradient (HOG), and Support Vector Machines (SVM) method to license plate detection so it will increase the detection level even though the image is not in a good quality. The image proceed by Sliding Window method in order to find plate position. Feature extraction in every window movement had been done by HOG and SVM method. Good result had shown in this research, which is 96% of accuracy.

Multipactor saturation in parallel-plate waveguides

International Nuclear Information System (INIS)

Sorolla, E.; Mattes, M.

2012-01-01

The saturation stage of a multipactor discharge is considered of interest, since it can guide towards a criterion to assess the multipactor onset. The electron cloud under multipactor regime within a parallel-plate waveguide is modeled by a thin continuous distribution of charge and the equations of motion are calculated taking into account the space charge effects. The saturation is identified by the interaction of the electron cloud with its image charge. The stability of the electron population growth is analyzed and two mechanisms of saturation to explain the steady-state multipactor for voltages near above the threshold onset are identified. The impact energy in the collision against the metal plates decreases during the electron population growth due to the attraction of the electron sheet on the image through the initial plate. When this growth remains stable till the impact energy reaches the first cross-over point, the electron surface density tends to a constant value. When the stability is broken before reaching the first cross-over point the surface charge density oscillates chaotically bounded within a certain range. In this case, an expression to calculate the maximum electron surface charge density is found whose predictions agree with the simulations when the voltage is not too high.

Toward 1-mm depth precision with a solid state full-field range imaging system

Science.gov (United States)

Dorrington, Adrian A.; Carnegie, Dale A.; Cree, Michael J.

2006-02-01

Previously, we demonstrated a novel heterodyne based solid-state full-field range-finding imaging system. This system is comprised of modulated LED illumination, a modulated image intensifier, and a digital video camera. A 10 MHz drive is provided with 1 Hz difference between the LEDs and image intensifier. A sequence of images of the resulting beating intensifier output are captured and processed to determine phase and hence distance to the object for each pixel. In a previous publication, we detailed results showing a one-sigma precision of 15 mm to 30 mm (depending on signal strength). Furthermore, we identified the limitations of the system and potential improvements that were expected to result in a range precision in the order of 1 mm. These primarily include increasing the operating frequency and improving optical coupling and sensitivity. In this paper, we report on the implementation of these improvements and the new system characteristics. We also comment on the factors that are important for high precision image ranging and present configuration strategies for best performance. Ranging with sub-millimeter precision is demonstrated by imaging a planar surface and calculating the deviations from a planar fit. The results are also illustrated graphically by imaging a garden gnome.

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.

Perceptual evaluation of different image fusion schemes

NARCIS (Netherlands)

Toet, A.; Franken, E.M.

2003-01-01

Human scene recognition performance was tested with images of night-time outdoor scenes. The scenes were registered both with a dual band (visual and near infrared) image intensified low-light CCD camera (DII) and with a thermal middle wavelength band (3–5 mm) infrared (IR) camera. Fused imagery was

Isolated tympanic plate fracture frequency and its relationship to mandibular trauma.

Science.gov (United States)

Altay, Canan; Erdoğan, Nezahat; Batkı, Ozan; Eren, Erdem; Altay, Sedat; Karasu, Sebnem; Mete, Berna; Uluç, Engin

2014-11-01

This study evaluated the prevalence of isolated tympanic fractures and their correlation with mandibular fractures by using maxillofacial computed tomography (CT). We retrospectively evaluated the maxillofacial CT of 1590 patients who presented to our emergency department with maxillofacial trauma between December 2010 and December 2012. Maxillofacial CT was used as the criterion standard for evaluating patients with maxillofacial fractures. The CT images were evaluated by using an electronic picture archiving and communications system and interpreted independently by 2 radiologists. The maxillofacial CT images revealed mandibular fractures in 167 of the patients and isolated tympanic plate fractures in 35 of these 167 patients. Four patients (11%) had a bilateral tympanic plate fracture, and 31 patients (89%) had unilateral tympanic plate fracture. Of all the tympanic plate fractures, 19 (54%) were on the right side and 16 (46%) were on the left side (P > .05). In our results, a significant correlation between the presence of a right-sided tympanic plate fracture and fracture of the ipsilateral condylar process was found (P = .036). However, a statistically significant difference between the presence of a tympanic plate fracture and other mandible fractures, additional soft-tissue findings, or the number of fractures was not determined (P > .05). Sex had no impact on the presence of tympanic plate fracture (P > .05). The frequency of isolated tympanic plate fractures in maxillofacial trauma is low, but it is an important anatomic location. Condyle fractures are significantly associated with isolated tympanic plate fractures. The presence of these injuries should raise suspicion of a concomitant isolated tympanic plate fracture. Copyright © 2014 Canadian Association of Radiologists. Published by Elsevier Inc. All rights reserved.

Quantitative assessment of growth plate activity

International Nuclear Information System (INIS)

Harcke, H.T.; Macy, N.J.; Mandell, G.A.; MacEwen, G.D.

1984-01-01

In the immature skeleton the physis or growth plate is the area of bone least able to withstand external forces and is therefore prone to trauma. Such trauma often leads to premature closure of the plate and results in limb shortening and/or angular deformity (varus or valgus). Active localization of bone seeking tracers in the physis makes bone scintigraphy an excellent method for assessing growth plate physiology. To be most effective, however, physeal activity should be quantified so that serial evaluations are accurate and comparable. The authors have developed a quantitative method for assessing physeal activity and have applied it ot the hip and knee. Using computer acquired pinhole images of the abnormal and contralateral normal joints, ten regions of interest are placed at key locations around each joint and comparative ratios are generated to form a growth plate profile. The ratios compare segmental physeal activity to total growth plate activity on both ipsilateral and contralateral sides and to adjacent bone. In 25 patients, ages 2 to 15 years, with angular deformities of the legs secondary to trauma, Blount's disease, and Perthes disease, this technique is able to differentiate abnormal segmental physeal activity. This is important since plate closure does not usually occur uniformly across the physis. The technique may permit the use of scintigraphy in the prediction of early closure through the quantitative analysis of serial studies

Vehicle Plate Detection in Car Black Box Video

Directory of Open Access Journals (Sweden)

Dongjin Park

2017-01-01

Full Text Available Internet services that share vehicle black box videos need a way to obfuscate license plates in uploaded videos because of privacy issues. Thus, plate detection is one of the critical functions that such services rely on. Even though various types of detection methods are available, they are not suitable for black box videos because no assumption about size, number of plates, and lighting conditions can be made. We propose a method to detect Korean vehicle plates from black box videos. It works in two stages: the first stage aims to locate a set of candidate plate regions and the second stage identifies only actual plates from candidates by using a support vector machine classifier. The first stage consists of five sequential substeps. At first, it produces candidate regions by combining single character areas and then eliminates candidate regions that fail to meet plate conditions through the remaining substeps. For the second stage, we propose a feature vector that captures the characteristics of plates in texture and color. For performance evaluation, we compiled our dataset which contains 2,627 positive and negative images. The evaluation results show that the proposed method improves accuracy and sensitivity by at least 5% and is 30 times faster compared with an existing method.

Ponderomotive phase plate for transmission electron microscopes

Science.gov (United States)

Reed, Bryan W [Livermore, CA

2012-07-10

A ponderomotive phase plate system and method for controllably producing highly tunable phase contrast transfer functions in a transmission electron microscope (TEM) for high resolution and biological phase contrast imaging. The system and method includes a laser source and a beam transport system to produce a focused laser crossover as a phase plate, so that a ponderomotive potential of the focused laser crossover produces a scattering-angle-dependent phase shift in the electrons of the post-sample electron beam corresponding to a desired phase contrast transfer function.

Aluminum Nitride Ceramic as an Optically Stimulable Luminescence Dosimeter Plate

Directory of Open Access Journals (Sweden)

Go Okada

2016-04-01

Full Text Available Photostimulable storage phosphors have been used in a wide range of applications including radiation measurements in one- and two-dimensional spaces, called point dosimetry and radiography. In this work, we report that an aluminum nitride (AlN ceramic plate, which is practically used as a heat sink (SHAPAL®, Tokuyama Corp., Yamaguchi, Japan, shows good optically-stimulated luminescence (OSL properties with sufficiently large signal and capability for imaging applications, and we have characterized the AlN plate for OSL applications. Upon interaction with X-rays, the sample color turns yellowish, due to a radiation-induced photoabsorption band in the UV-blue range below ~500 nm. After irradiating the sample with X-rays, an intense OSL emission can be observed in the UV (360 nm spectral region during stimulation by red light. Although our measurement setup is not optimized, dose detection was confirmed as low as ~3 mGy to over 20 Gy. Furthermore, we have successfully demonstrated that the SHAPAL® AlN ceramic plate has great potential to be used as an imaging plate in radiography.

Computed radiography

International Nuclear Information System (INIS)

Pupchek, G.

2004-01-01

Computed radiography (CR) is an image acquisition process that is used to create digital, 2-dimensional radiographs. CR employs a photostimulable phosphor-based imaging plate, replacing the standard x-ray film and intensifying screen combination. Conventional radiographic exposure equipment is used with no modification required to the existing system. CR can transform an analog x-ray department into a digital one and eliminates the need for chemicals, water, darkrooms and film processor headaches. (author)

A trial fabrication of activity standard surface sources and positional standard surface sources for an imaging plate system

International Nuclear Information System (INIS)

Sato, Yasushi; Hino, Yoshio; Yamada, Takahiro; Matsumoto, Mikio

2003-01-01

An imaging plate system can detect low level activity, but quantitative analysis is difficult because there are no adequate standard surface sources. A new fabrication method was developed for standard surface sources by printing on a sheet of paper using an ink-jet printer with inks in which a radioactive material was mixed. The fabricated standard surface sources had high uniformity, high positional resolution arbitrary shapes and a broad intensity range. The standard sources were used for measurement of surface activity as an application. (H. Yokoo)

An automated wide-field time-gated optically sectioning fluorescence lifetime imaging multiwell plate reader for high-content analysis of protein-protein interactions

Science.gov (United States)

Alibhai, Dominic; Kumar, Sunil; Kelly, Douglas; Warren, Sean; Alexandrov, Yuriy; Munro, Ian; McGinty, James; Talbot, Clifford; Murray, Edward J.; Stuhmeier, Frank; Neil, Mark A. A.; Dunsby, Chris; French, Paul M. W.

2011-03-01

We describe an optically-sectioned FLIM multiwell plate reader that combines Nipkow microscopy with wide-field time-gated FLIM, and its application to high content analysis of FRET. The system acquires sectioned FLIM images in fluorescent protein. It has been applied to study the formation of immature HIV virus like particles (VLPs) in live cells by monitoring Gag-Gag protein interactions using FLIM FRET of HIV-1 Gag transfected with CFP or YFP. VLP formation results in FRET between closely packed Gag proteins, as confirmed by our FLIM analysis that includes automatic image segmentation.

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.

Electronic imaging applied to neutron radiography

International Nuclear Information System (INIS)

Garrett, D.A.; Bracher, D.A.

1976-01-01

A commercially - available image intensifier was used with a scan conversion memory and a mobile 252 Cf based neutron radiography system to obtain neutron radiographs on a television monitor in 0.5 minutes to 10.0 minutes

Spirit Beside 'Home Plate,' Sol 1809 (Stereo)

Science.gov (United States)

2009-01-01

[figure removed for brevity, see original site] Left-eye view of a color stereo pair for PIA11803 [figure removed for brevity, see original site] Right-eye view of a color stereo pair for PIA11803 NASA Mars Exploration Rover Spirit used its navigation camera to take the images assembled into this stereo, 120-degree view southward after a short drive during the 1,809th Martian day, or sol, of Spirit's mission on the surface of Mars (February 3, 2009). By combining images from the left-eye and right-eye sides of the navigation camera, the view appears three-dimensional when viewed through red-blue glasses with the red lens on the left. Spirit had driven about 2.6 meters (8.5 feet) that sol, continuing a clockwise route around a low plateau called 'Home Plate.' In this image, the rocks visible above the rovers' solar panels are on the slope at the northern edge of Home Plate. This view is presented as a cylindrical-perspective projection with geometric seam correction.

A new license plate extraction framework based on fast mean shift

Science.gov (United States)

Pan, Luning; Li, Shuguang

2010-08-01

License plate extraction is considered to be the most crucial step of Automatic license plate recognition (ALPR) system. In this paper, a region-based license plate hybrid detection method is proposed to solve practical problems under complex background in which existing large quantity of disturbing information. In this method, coarse license plate location is carried out firstly to get the head part of a vehicle. Then a new Fast Mean Shift method based on random sampling of Kernel Density Estimate (KDE) is adopted to segment the color vehicle images, in order to get candidate license plate regions. The remarkable speed-up it brings makes Mean Shift segmentation more suitable for this application. Feature extraction and classification is used to accurately separate license plate from other candidate regions. At last, tilted license plate regulation is used for future recognition steps.

Thermal performance of plate-type loop thermosyphon at sub-atmospheric pressures

International Nuclear Information System (INIS)

Tsoi, Vadim; Chang, Shyy Woei; Chiang Kuei Feng; Huang, Chuan Chin

2011-01-01

This experimental study examines the thermal performance of a newly devised plate-type two-phase loop thermosyphon with cooling applications to electronic boards of telecommunication systems. The evaporation section is configured as the inter-connected multi channels to emulate the bridging boiling mechanism in pulsating thermosyphon. Two thermosyphon plates using water as the coolant with filling ratios (FR) of 0.22 and 0.32 are tested at sub-atmospheric pressures. The vapor-liquid flow images as well as the thermal resistances and effective spreading thermal conductivities are individually measured for each thermosyphon test plate at various heating powers. The high-speed digital images of the vapor-liquid flow structures reveal the characteristic boiling phenomena and the vapor-liquid circulation in the vertical thermosyphon plate, which assist to explore the thermal physics for this type of loop thermosyphon. The bubble agglomeration and pumping action in the inter-connected boiling channels take place at metastable non-equilibrium conditions, leading to the intermittent slug flows with a pulsation character. Such hybrid loop-pulsating thermosyphon permits the vapor-liquid circulation in the horizontal plate. Thermal resistances and spreading thermal conductivities detected from the present thermosyphon plates; the vapor chamber flat plate heat pipe and the copper plate at free and forced convective cooling conditions with both vertical and horizontal orientations are cross-examined. In most telecommunication systems and units, the electrical boards are vertical so that the thermal performance data on the vertical thermosyphon are most relevant to this particular application. - Highlights: → We examine thermal performances of plate-type loop thermosyphon. → Thermal resistances and spreading conductivities are examined. → Bubble agglomeration in inter-connected boiling channels generates intermittent slug flows with pulsations. → Boiling instability

The Sydney University PAPA camera

Science.gov (United States)

Lawson, Peter R.

1994-04-01

The Precision Analog Photon Address (PAPA) camera is a photon-counting array detector that uses optical encoding to locate photon events on the output of a microchannel plate image intensifier. The Sydney University camera is a 256x256 pixel detector which can operate at speeds greater than 1 million photons per second and produce individual photon coordinates with a deadtime of only 300 ns. It uses a new Gray coded mask-plate which permits a simplified optical alignment and successfully guards against vignetting artifacts.

Growth plate injury at the base of the coracoid: MRI features

Energy Technology Data Exchange (ETDEWEB)

FitzGerald Alaia, Erin; Rosenberg, Zehava Sadka; Pinkney, Lynne [NYU Langone Medical Center, Department of Radiology, New York, NY (United States); Rossi, Ignacio [Centro de Diagnostico Dr. Enrique Rossi, Buenos Aires (Argentina); Zember, Jonathan [Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States); Roedl, Johannes B. [Thomas Jefferson University Hospital, Department of Radiology, Philadelphia, PA (United States); Steinbach, Lynne S. [University of California, San Francisco Medical Center, Department of Radiology, San Francisco, CA (United States)

2017-11-15

To assess the MRI features of growth plate injury at the base of the coracoid process. Subjects were identified through retrospective search of our department imaging database and teaching files and the teaching files of two outside academic institutions. The coracoid base growth plate was examined with attention to widening, irregularity, abnormal signal intensity of the growth plate, and the presence of adjacent soft tissue edema. The apposing coracoid and scapular bony surfaces were examined for signal intensity and morphology. Shoulder MRIs in eight patients with coracoid base growth plate disturbances were retrospectively reviewed (7 males, 1 female, mean age 15 years). Growth plate injury manifested as widening, irregularity and increased signal, apposing bony marrow edema and hypertrophy, and surrounding soft tissue edema. Five subjects were athletes (football, archery, basketball, swimming, rugby), two had a history of neuromuscular disorders, and one subject presented after a fall. Clinical indications included: rule out labral tear (n = 3), rule out rotator cuff tear or fracture after fall (n = 1), nonspecific pain (n = 1), shoulder subluxation, rule out glenoid pathology (n = 1, patient with underlying neuromuscular disorder), muscular dystrophy with shoulder pain (n = 1), and impingement (n = 1). Coracoid growth plate injury was not suspected clinically in any of the patients. Awareness of the imaging appearance of coracoid base growth plate injury can aid in a more accurate diagnosis of shoulder MRI studies in young pediatric athletes. While uncommon, coracoid growth plate injury should be considered when assessing children with shoulder symptomatology. (orig.)

Growth plate injury at the base of the coracoid: MRI features

International Nuclear Information System (INIS)

FitzGerald Alaia, Erin; Rosenberg, Zehava Sadka; Pinkney, Lynne; Rossi, Ignacio; Zember, Jonathan; Roedl, Johannes B.; Steinbach, Lynne S.

2017-01-01

To assess the MRI features of growth plate injury at the base of the coracoid process. Subjects were identified through retrospective search of our department imaging database and teaching files and the teaching files of two outside academic institutions. The coracoid base growth plate was examined with attention to widening, irregularity, abnormal signal intensity of the growth plate, and the presence of adjacent soft tissue edema. The apposing coracoid and scapular bony surfaces were examined for signal intensity and morphology. Shoulder MRIs in eight patients with coracoid base growth plate disturbances were retrospectively reviewed (7 males, 1 female, mean age 15 years). Growth plate injury manifested as widening, irregularity and increased signal, apposing bony marrow edema and hypertrophy, and surrounding soft tissue edema. Five subjects were athletes (football, archery, basketball, swimming, rugby), two had a history of neuromuscular disorders, and one subject presented after a fall. Clinical indications included: rule out labral tear (n = 3), rule out rotator cuff tear or fracture after fall (n = 1), nonspecific pain (n = 1), shoulder subluxation, rule out glenoid pathology (n = 1, patient with underlying neuromuscular disorder), muscular dystrophy with shoulder pain (n = 1), and impingement (n = 1). Coracoid growth plate injury was not suspected clinically in any of the patients. Awareness of the imaging appearance of coracoid base growth plate injury can aid in a more accurate diagnosis of shoulder MRI studies in young pediatric athletes. While uncommon, coracoid growth plate injury should be considered when assessing children with shoulder symptomatology. (orig.)

Using Brief Experimental Analysis to Intensify Tier 3 Reading Interventions

Science.gov (United States)

Coolong-Chaffin, Melissa; Wagner, Dana

2015-01-01

As implementation of multi-tiered systems of support becomes common practice across the nation, practitioners continue to need strategies for intensifying interventions and supports for the subset of students who fail to make adequate progress despite strong programs at Tiers 1 and 2. Experts recommend making several changes to the structure and…

Growth plate closure: Apex view on bone scan

International Nuclear Information System (INIS)

Giles, P.H.; Trochei, M.; Yeates, K.

1984-01-01

Angular deformities of the extremities in children following premature closure of the growth plate are well known. The deformities depend on the position of an osseus bridge which forms between the epiphysis and metaphysis. Several surgical procedures including resection of the osseus bridge have been described, however, delineation of the site of fusion is difficult to define. The commonest site of growth plate arrest is the distal femoral or proximal tibial growth plate. A new technique using the bone scan has been developed which accurately defines the area and position of these osseus bridges. Two hours after injection of technetium 99m methylene diphosphonate apex views of the affected distal femoral growth plate were performed. The knee was flexed into its smallest angle. Using a pinhole collimator the gamma camera was angled to face the affected growth plate end on. The image was collected onto computer and analysed by: (I) regions of interest over segments of the growth plate to calculate the relative area of total growth plate affected: (II) generating histograms: (III) thresholding or performing isocontours to accentuate abnormal areas. The growth plate is normally uniformly increased when compared to the normal shaft of the bone. Fusion across the plate appears as an area of diminished uptake. The apex view gives a unique functional map of the growth plate such that abnormal areas are displayed, and the site, size and position of osseus fusion obtained. The technique has the potential for determining the metabolic activity of the growth plate before and after surgery. Serial studies will allow assessment of regneration of the plate and reformation of new osseus bridges

Ultraviolet light imaging technology and applications

Science.gov (United States)

Yokoi, Takane; Suzuki, Kenji; Oba, Koichiro

1991-06-01

Demands on the high-quality imaging in ultraviolet (UV) light region have been increasing recently, especially in fields such as forensic investigations, laser experiments, spent fuel identification, and so on. Important requirements on the UV imaging devices in such applications are high sensitivity, excellent solar blindness, and small image distortion, since the imaging of very weak UV images are usually carried out under natural sunlight or room illuminations and the image data have to be processed to produce useful two-dimensional quantitative data. A new photocathode has been developed to meet these requirements. It is specially made of RbTe on a sapphire window and its quantum efficiency is as high as 20% with the solar blindness of 10,000. The tube is specially designed to meet UV light optics and to minimize image distortion. It has an invertor type image intensifier tube structure and intensifies the incident UV light up to approximately 10,000 times. The distortion of the output image is suppressed less than 1.8%, because of a specially designed electron optic lens system. The device has shown excellent results in the observation of such objects as fingerprints and footprints in forensic investigations, the Cherenkov light produced by the spent fuels stored in a cooling water pool in the nuclear power station, and UV laser beam path in excimer laser experiments. Furthermore, many other applications of the UV light imaging will be expected in various fields such as semiconductors, cosmetics, and electrical power.

Hydrodynamics of a flexible plate between pitching rigid plates

Science.gov (United States)

Kim, Junyoung; Kim, Daegyoum

2017-11-01

The dynamics of a flexible plate have been studied as a model problem in swimming and flying of animals and fluid-structure interaction of plants and flags. Motivated by fish schooling and an array of sea grasses, we investigate the dynamics of a flexible plate closely placed between two pitching rigid plates. In most studies on passive deformation of the flexible plate, the plate is immersed in a uniform flow or a wavy flow. However, in this study, the flexible plate experiences periodic deformation by the oscillatory flow generated by the prescribed pitching motion of the rigid plates. In our model, the pitching axes of the rigid plates and the clamping position of the flexible plate are aligned on the same line. The flexible plate shows various responses depending on length and pitching frequency of rigid plates, thickness of a flexible plate, and free-stream velocity. To find the effect of each variable on the response of the flexible plate, amplitude of a trailing edge and modal contribution of a flapping motion are compared, and flow structure around the flexible plate is examined.

Position-sensitive detector system OBI for High Resolution X-Ray Powder Diffraction using on-site readable image plates

International Nuclear Information System (INIS)

Knapp, M.; Joco, V.; Baehtz, C.; Brecht, H.H.; Berghaeuser, A.; Ehrenberg, H.; Seggern, H. von; Fuess, H.

2004-01-01

A one-dimensional detector system has been developed using image plates. The detector is working in transmission mode or Debye-Scherrer geometry and is on-site readable which reduces the effort for calibration. It covers a wide angular range up to 110 deg. and shows narrow reflection half-widths depending on the capillary diameter. The acquisition time is in the range of minutes and the data quality allows for reliable Rietveld refinement of complicated structures, even in multi-phase samples. The detector opens a wide field of new applications in kinetics and temperature resolved measurements

Evaluation Of Medical Fluoroscopy Imaging

International Nuclear Information System (INIS)

Hartana, Budi; Santoso

2000-01-01

It has been done to evaluate image system of medical fluoroscopic machine by Leeds Test Object (LTO). Two x-ray potentials of 70 kV and 40-60 kV were used to evaluate image by LTO on monitor and oscilloscope. Performance of imaging system decreased for some parameters of video signal, linearity of television scan, contras threshold of 4.5%, distortion integral of 65.1%, and focus uniformity decrease to edge image. Comparison of field diameter of television image to intensifier field vertically and horizontally were respectively 221:230 and 205:230, symmetrically vignetting, spatial resolution limit is 1.26 lp/mm

Astrometric properties of the Tautenburg Plate Scanner

Science.gov (United States)

Brunzendorf, Jens; Meusinger, Helmut

The Tautenburg Plate Scanner (TPS) is an advanced plate-measuring machine run by the Thüringer Landessternwarte Tautenburg (Karl Schwarzschild Observatory), where the machine is housed. It is capable of digitising photographic plates up to 30 cm × 30 cm in size. In our poster, we reported on tests and preliminary results of its astrometric properties. The essential components of the TPS consist of an x-y table movable between an illumination system and a direct imaging system. A telecentric lens images the light transmitted through the photographic emulsion onto a CCD line of 6000 pixels of 10 µm square size each. All components are mounted on a massive air-bearing table. Scanning is performed in lanes of up to 55 mm width by moving the x-y table in a continuous drift-scan mode perpendicular to the CCD line. The analogue output from the CCD is digitised to 12 bit with a total signal/noise ratio of 1000 : 1, corresponding to a photographic density range of three. The pixel map is produced as a series of optionally overlapping lane scans. The pixel data are stored onto CD-ROM or DAT. A Tautenburg Schmidt plate 24 cm × 24 cm in size is digitised within 2.5 hours resulting in 1.3 GB of data. Subsequent high-level data processing is performed off-line on other computers. During the scanning process, the geometry of the optical components is kept fixed. The optimal focussing of the optics is performed prior to the scan. Due to the telecentric lens refocussing is not required. Therefore, the main source of astrometric errors (beside the emulsion itself) are mechanical imperfections in the drive system, which have to be divided into random and systematic ones. The r.m.s. repeatability over the whole plate as measured by repeated scans of the same plate is about 0.5 µm for each axis. The mean plate-to-plate accuracy of the object positions on two plates with the same epoch and the same plate centre has been determined to be about 1 µm. This accuracy is comparable to

Epiphyseal plate closure of radio-ulna bone in red Sokoto goat ...

African Journals Online (AJOL)

They were classified into different age groups and subgroups, from 1-144 weeks. The radiographs of their forearms were taken and the proximal and distal epiphyseal plate lengths of both radius and ulna bones were measured. The radiographic images of the bones showed that the proximal and distal epiphyseal plates of ...

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.

Spirit's View Beside 'Home Plate' on Sol 1823 (Stereo)

Science.gov (United States)

2009-01-01

[figure removed for brevity, see original site] Left-eye view of a color stereo pair for PIA11971 [figure removed for brevity, see original site] Right-eye view of a color stereo pair for PIA11971 NASA's Mars Exploration Rover Spirit used its navigation camera to take the images that have been combined into this stereo, 180-degree view of the rover's surroundings during the 1,823rd Martian day, or sol, of Spirit's surface mission (Feb. 17, 2009). This view combines images from the left-eye and right-eye sides of the navigation camera. It appears three-dimensional when viewed through red-blue glasses with the red lens on the left. The center of the view is toward the south-southwest. The rover had driven 7 meters (23 feet) eastward earlier on Sol 1823, part of maneuvering to get Spirit into a favorable position for climbing onto the low plateau called 'Home Plate.' However, after two driving attempts with negligible progress during the following three sols, the rover team changed its strategy for getting to destinations south of Home Plate. The team decided to drive Spirit at least partway around Home Plate, instead of ascending the northern edge and taking a shorter route across the top of the plateau. Layered rocks forming part of the northern edge of Home Plate can be seen near the center of the image. Rover wheel tracks are visible at the lower edge. This view is presented as a cylindrical-perspective projection with geometric seam correction.

Improved pregnancy outcome in type 1 diabetic women with microalbuminuria or diabetic nephropathy: effect of intensified antihypertensive therapy?

DEFF Research Database (Denmark)

Nielsen, Lene Ringholm; Damm, Peter; Mathiesen, Elisabeth R

2009-01-01

To describe pregnancy outcome in type 1 diabetic women with normoalbuminuria, microalbuminuria, or diabetic nephropathy after implementation of an intensified antihypertensive therapeutic strategy.......To describe pregnancy outcome in type 1 diabetic women with normoalbuminuria, microalbuminuria, or diabetic nephropathy after implementation of an intensified antihypertensive therapeutic strategy....

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.

Possible application of an imaging plate to space radiation dosimetry

International Nuclear Information System (INIS)

Ohuchi, Hiroko; Yamadera, Akira

2002-01-01

Fading correction plays an important role in the application of commercially available BaBrF:Eu 2+ phosphors: imaging plates (IP) to dosimetry. We successfully determined a fading correction equation, which is a function of elapsed time and absolute temperature, as the sum of several exponentially decaying components having different half-lives. In this work, a new method was developed to eliminate a short half-life component by annealing the IP and estimating the radiation dose with the long half-life components. Annealing decreases the effect of fading on the estimated dose, however, it also causes the loss of photo-stimulated luminescence (PSL). Considering an IP as an integral detector for a specific period of up to one month, the practically optimum conditions for quantitative measurement with two types of IP (BAS-TR and BAS-MS) were evaluated by using the fading correction equation, which was obtained after irradiation with a 244 Cm source as the alpha-ray source having a specific radioactivity of 1,638.5 Bq/cm 2 including beta and gamma-ray (alpha energy of 5.763 and 5.805 MeV). Annealing at 80 deg C for 24 hours after irradiation for one month using BAS-MS should minimize the effect of the elapsed time, resulting in sufficient sensitivity. The results demonstrate new possibilities for radiation dosimetry offered by the use of an IP. (author)

Use of an X-ray imaging plate for stress analysis

International Nuclear Information System (INIS)

Schubert, A.; Kaempfe, B.; Ermrich, M.; Auerswald, E.; Traenkner, K.

1994-01-01

The X-ray diffraction method for stress measurements has been successfully carried out for many years [1]. The basis for the determination of residual and load stresses is the Debye-Scherrer-method and Bragg's law. The Bragg angles of one or several reflections are measured with high precision in the back reflection region. The results permit the determination of changes in interplanar spacings of polycrystalline materials. Conventional stress analysis is based on two commonly used techniques, the so-called ''sin 2 ψ''- and ''φ''-methods, which require measurements at different tilting and rotating positions of the sample by the help of a Ψ- or Ω-goniometer [1, 2, 3]. In these cases the interplanar spacings and consequently the shift of the peak can be determined with conventional counters or position sensitive detectors. From the whole diffraction cone only a small part of lattice planes {hkl} with a special orientation (ψ, φ) is analysed. The use of a two-dimensional detector like an imaging plate [4] offers the possibility to get diffraction patterns in one measurement from lattice planes {hkl} having one ψ and all φ orientations (non-tilted case) or different ψ and different φ orientations (tilted case). Thus the number of measurements for the calculation of the stress components can be significantly reduced. Further it is possible to investigate both textured materials and coarse-grained samples. (orig.)

Dysphagia screening and intensified oral hygiene reduce pneumonia after stroke

DEFF Research Database (Denmark)

Sørensen, Rikke Terp; Rasmussen, Rune Skovgaard; Overgaard, Karsten

2013-01-01

Dysphagia occurs in approximately 51%-78% of patients with acute stroke. The incidence of pneumonia caused by aspiration in dysphagic patients increases both mortality and the need for hospitalization. The aim of this study was to investigate whether the incidence of aspiration pneumonia could...... be reduced in such patients by an early screening for dysphagia and intensified oral hygiene....

Recognition Number of The Vehicle Plate Using Otsu Method and K-Nearest Neighbour Classification

Directory of Open Access Journals (Sweden)

Maulidia Rahmah Hidayah

2017-05-01

Full Text Available The current topic that is interesting as a solution of the impact of public service improvement toward vehicle is License Plate Recognition (LPR, but it still needs to develop the research of LPR method. Some of the previous researchs showed that K-Nearest Neighbour (KNN succeed in car license plate recognition. The Objectives of this research was to determine the implementation and accuracy of Otsu Method toward license plate recognition. The method of this research was Otsu method to extract the characteristics and image of the plate into binary image and KNN as recognition classification method of each character. The development of the license plate recognition program by using Otsu method and classification of KNN is following the steps of pattern recognition, such as input and sensing, pre-processing, extraction feature Otsu method binary, segmentation, KNN classification method and post-processing by calculating the level of accuracy. The study showed that this program can recognize by 82% from 100 test plate with 93,75% of number recognition accuracy and 91,92% of letter recognition accuracy. 

Relative range error evaluation of terrestrial laser scanners using a plate, a sphere, and a novel dual-sphere-plate target.

Science.gov (United States)

Muralikrishnan, Bala; Rachakonda, Prem; Lee, Vincent; Shilling, Meghan; Sawyer, Daniel; Cheok, Geraldine; Cournoyer, Luc

2017-12-01

Terrestrial laser scanners (TLS) are a class of 3D imaging systems that produce a 3D point cloud by measuring the range and two angles to a point. The fundamental measurement of a TLS is range. Relative range error is one component of the overall range error of TLS and its estimation is therefore an important aspect in establishing metrological traceability of measurements performed using these systems. Target geometry is an important aspect to consider when realizing the relative range tests. The recently published ASTM E2938-15 mandates the use of a plate target for the relative range tests. While a plate target may reasonably be expected to produce distortion free data even at far distances, the target itself needs careful alignment at each of the relative range test positions. In this paper, we discuss relative range experiments performed using a plate target and then address the advantages and limitations of using a sphere target. We then present a novel dual-sphere-plate target that draws from the advantages of the sphere and the plate without the associated limitations. The spheres in the dual-sphere-plate target are used simply as fiducials to identify a point on the surface of the plate that is common to both the scanner and the reference instrument, thus overcoming the need to carefully align the target.

Can pterygoid plate asymmetry be linked to temporomandibular joint disorders ?

Energy Technology Data Exchange (ETDEWEB)

Guerrero, Maria Eugenia; Jacobs, Reinhilde [OIC, OMFS IMPATH Research Group, Department of Imaging and Pathology, Faculty of Medicine, University of Leuven and Oral and Maxillofacial Surgery, University Hospitals Leuven, Leuven (Belgium); Beltran, Jorge [Oral and Maxillofacial Radiology, Post-Graduate School, Universidad Privada Cayetano Heredia, Lima (Peru); Laat, Antoon [Stomatology and Maxillofacial Surgery, Dept. of Oral Health Sciences, KU Leuven, Leuven (Belgium)

2015-06-15

This study was performed to evaluate the relationship between pterygoid plate asymmetry and temporomandibular joint disorders. Cone-beam computed tomography (CBCT) images of 60 patients with temporomandibular disorders (TMD) involving pain were analyzed and compared with images of 60 age- and gender-matched controls. Three observers performed linear measurements of the lateral pterygoid plates. Statistically significant differences were found between measurements of the lateral pterygoid plates on the site that had pain and the contralateral site (p<0.05). The average length of the lateral pterygoid plates (LPPs) in patients with TMD was 17.01±3.64 mm on the right side and 16.21±3.51 mm on the left side, and in patients without TMD, it was 11.86±1.97 mm on the right side and 11.98±1.85 mm on the left side. Statistically significant differences in the LPP length, measured on CBCT, were found between patients with and without TMD (p<0.05). The inter-examiner reliability obtained in this study was very high for all the examiners (0.99, 95% confidence interval: 0.98-0.99). Within the limits of the present study, CBCT lateral pterygoid plate measurements at the side with TMD were found to be significantly different from those on the side without TMD. More research is needed to explore potential etiological correlations and implications for treatment.

virtX - a computer based system for training the intrasurgical use of mobile image intensifier systems

Directory of Open Access Journals (Sweden)

Pretschner, Dietrich Peter

2006-11-01

Full Text Available Background and objectives: Currently the correct intrasurgical positioning and adjustment of mobile X-ray image intensifiers (C-arm can be learned theoretically through the use of textbooks, the practical training with the device itself suffers from the lack of visual feedback, i.e. radiographs corresponding to the adjustment of the C-arm. This leads to the question, whether the training of correct operation and adjustment of a C-arm in different operation scenarios can be supported by a C-arm simulation system being part of a CBT system (Computer Based Training. Methods: In co-operation with physicians from accident surgery and radiology the computer-based training system virtX was developed. virtX confronts the user with different exercises of C-arm adjustment and evaluates their execution and the results. These tasks can be created with the help of an authoring tool and can be accomplished by the trainee in different modes: a pure virtual mode and a combined virtual-real mode. In the pure virtual mode the user controls the virtual C-arm in a virtual operating theatre via the graphic-interactive virtX user interface. In the virtual-real mode however the position and orientation of a real C-arm are detected and mapped onto the virtual C-arm. At any time during the completion of an exercise the user can produce a close-to-reality, virtual radiograph and can control all parameters, like the positions of the apertures, X-ray intensity, etc. virtX was used on a three-day course for OR personnel with 120 participants and evaluated using questionnaires.Results: 79 of the participants returned a questionnaire. The average age of the 62 female and 15 male participants (two n.s. was 34 ± 9 years, their professional experience was 8.3 ± 7.6 years. 18 persons (23% indicated to work occasionally with a C-arm, 61 (77% worked regularly with it. Over 83% of the interviewed participants considered virtX a useful addition to the conventional C-arm training

Determination of Proper Motions of Circumpolar Stars by Using Images from Ukrvo Plate Archives

Science.gov (United States)

Protsyuk, Yu.; Andruk, V.; Mazhaev, A.; Kovylianska, O.; Protsyuk, S.; Golovnya, V.

UkrVO plate archives contain informationobtained at different time periods and in different observatories for the same regions of the sky [3, 5, 6, 7, 8]. It allows us to carry out joint processing of plates and to receive new results for interesting objects. To obtain proper motions of stars in circumpolar areas, we selected 34 photographic plates from the RI NAO archive and 161 plates from the archive of the MAO NAS. A mean epoch difference between the plates from these archives is 55 years. Scanning of the plates and data processing were independently carried out by both observatories. A catalog of equatorial positions for 195 thousand stars up to 15m was compiled in the RI NAO (black dots in Fig. 1). A catalog of equatorial positions for 1050 thousand stars up to 16.5m was compiled in MAO (gray dots in Fig. 1). A comparison of positions for common stars contained in these catalogs was conducted. A catalog of proper motions for 30 thousand common stars up to 15m was compiled using these two input catalogs. The obtained result suggests the advisability of processing of all observations to receive proper motions of stars up to 14-15m in the declination zone of 65° to 90°.

A High-Speed, Event-Driven, Active Pixel Sensor Readout for Photon-Counting Microchannel Plate Detectors

Science.gov (United States)

Kimble, Randy A.; Pain, Bedabrata; Norton, Timothy J.; Haas, J. Patrick; Oegerle, William R. (Technical Monitor)

2002-01-01

Silicon array readouts for microchannel plate intensifiers offer several attractive features. In this class of detector, the electron cloud output of the MCP intensifier is converted to visible light by a phosphor; that light is then fiber-optically coupled to the silicon array. In photon-counting mode, the resulting light splashes on the silicon array are recognized and centroided to fractional pixel accuracy by off-chip electronics. This process can result in very high (MCP-limited) spatial resolution while operating at a modest MCP gain (desirable for dynamic range and long term stability). The principal limitation of intensified CCD systems of this type is their severely limited local dynamic range, as accurate photon counting is achieved only if there are not overlapping event splashes within the frame time of the device. This problem can be ameliorated somewhat by processing events only in pre-selected windows of interest of by using an addressable charge injection device (CID) for the readout array. We are currently pursuing the development of an intriguing alternative readout concept based on using an event-driven CMOS Active Pixel Sensor. APS technology permits the incorporation of discriminator circuitry within each pixel. When coupled with suitable CMOS logic outside the array area, the discriminator circuitry can be used to trigger the readout of small sub-array windows only when and where an event splash has been detected, completely eliminating the local dynamic range problem, while achieving a high global count rate capability and maintaining high spatial resolution. We elaborate on this concept and present our progress toward implementing an event-driven APS readout.

AA, beam stopper with scintillator screen

CERN Multimedia

CERN PhotoLab

1980-01-01

An insertable steel-plate beam stopper was located after nearly a full turn downstream of the injection point. It was fitted with a scintillator screen, a thin plate of Cr-doped alumina, imprinted with a grid and reference points. The screen was illuminated through a window and observed with a highly sensitive TV camera plus image intensifier. This allowed observation of beam position and size of a proton test beam and of the beam from the target, which consisted not only of antiprotons but contained as well electrons, pions and muons of the same momentum.

A comparison of image quality and dose requirements of a new conventional film-screen system for skeletal radiography

International Nuclear Information System (INIS)

Freitag, P.; Gueckel, C.; Fournier, P.J.; Roth, J.; Steinbrich, W.

1995-01-01

This paper compares a new film-screen system (FSS) called INSIGHT Skeletal Imaging System with the previously used Lanex/T-MAT G FSS. Using a Bronder phantom, measurements were made of dose, resolution and contrast. 135 skeletal phantom images were assessed in order of quality by six observers. Comparable high resolution film-screen combinations (FSC) showed similar geometric resolution. Comparing high intensifying screens, the new INSIGHT Skeletal Regular FSS showed better resolution than the Lanex medium FSC. Dose reduction for the INSIGHT Skeletal Imaging FSS was 29-56%. The new FSS showed image quality similar to high resolution screens but was significantly better when using high intensifying screens. (orig./MG) [de

Experimental investigations of image quality in X-ray mammography with conventional screen film system (SFS), digital phosphor storage plate in/without magnification technique (CR) and digital CCD-technique (CCD)

International Nuclear Information System (INIS)

Schulz-Wendtland, R.; Aichinger, U.; Boehner, C.; Dobritz, M.; Wenkel, E.; Bautz, W.; Saebel, M.

2001-01-01

Comparison of image quality in X-ray mammography between conventional film screen film system (SFS), digital phosphor storage plate in and without magnification technique (CR) and digital CCD-technique (CCD). Radiograms of an RMI-mammography phantom were acquired using a conventional screen film system, three digital storage plate systems and two digital systems in CCD-technique. Additionally the radiograms of one digital phosphor storage plate system were post-processed regarding contrast and included in the comparison. The detectability of details was best with the digital mammography in CCD-technique. After confirming these promising results in clinical studies, digital mammography should be able to replace conventional screen film technique. (orig.)

Effects of repetitive or intensified instructions in telephone assisted, bystander cardiopulmonary resuscitation: an investigator-blinded, 4-armed, randomized, factorial simulation trial.

Science.gov (United States)

van Tulder, R; Roth, D; Krammel, M; Laggner, R; Heidinger, B; Kienbacher, C; Novosad, H; Chwojka, C; Havel, C; Sterz, F; Schreiber, W; Herkner, H

2014-01-01

Compression depth is frequently suboptimal in cardiopulmonary resuscitation (CPR). We investigated effects of intensified wording and/or repetitive target depth instructions on compression depth in telephone-assisted, protocol driven, bystander CPR on a simulation manikin. Thirty-two volunteers performed 10 min of compression only-CPR in a prospective, investigator-blinded, 4-armed, factorial setting. Participants were randomized either to standard wording ("push down firmly 5 cm"), intensified wording ("it is very important to push down 5 cm every time") or standard or intensified wording repeated every 20s. Three dispatchers were randomized to give these instructions. Primary outcome was relative compression depth (absolute compression depth minus leaning depth). Secondary outcomes were absolute distance, hands-off times as well as BORG-scale and nine-hole peg test (NHPT), pulse rate and blood pressure to reflect physical exertion. We applied a random effects linear regression model. Relative compression depth was 35 ± 10 mm (standard) versus 31 ± 11 mm (intensified wording) versus 25 ± 8 mm (repeated standard) and 31 ± 14 mm (repeated intensified wording). Adjusted for design, body mass index and female sex, intensified wording and repetition led to decreased compression depth of 13 (95%CI -25 to -1) mm (p=0.04) and 9 (95%CI -21 to 3) mm (p=0.13), respectively. Secondary outcomes regarding intensified wording showed significant differences for absolute distance (43 ± 2 versus 20 (95%CI 3-37) mm; p=0.01) and hands-off times (60 ± 40 versus 157 (95%CI 63-251) s; p=0.04). In protocol driven, telephone-assisted, bystander CPR, intensified wording and/or repetitive target depth instruction will not improve compression depth compared to the standard instruction. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Benchmark for license plate character segmentation

Science.gov (United States)

Gonçalves, Gabriel Resende; da Silva, Sirlene Pio Gomes; Menotti, David; Shwartz, William Robson

2016-09-01

Automatic license plate recognition (ALPR) has been the focus of many researches in the past years. In general, ALPR is divided into the following problems: detection of on-track vehicles, license plate detection, segmentation of license plate characters, and optical character recognition (OCR). Even though commercial solutions are available for controlled acquisition conditions, e.g., the entrance of a parking lot, ALPR is still an open problem when dealing with data acquired from uncontrolled environments, such as roads and highways when relying only on imaging sensors. Due to the multiple orientations and scales of the license plates captured by the camera, a very challenging task of the ALPR is the license plate character segmentation (LPCS) step, because its effectiveness is required to be (near) optimal to achieve a high recognition rate by the OCR. To tackle the LPCS problem, this work proposes a benchmark composed of a dataset designed to focus specifically on the character segmentation step of the ALPR within an evaluation protocol. Furthermore, we propose the Jaccard-centroid coefficient, an evaluation measure more suitable than the Jaccard coefficient regarding the location of the bounding box within the ground-truth annotation. The dataset is composed of 2000 Brazilian license plates consisting of 14000 alphanumeric symbols and their corresponding bounding box annotations. We also present a straightforward approach to perform LPCS efficiently. Finally, we provide an experimental evaluation for the dataset based on five LPCS approaches and demonstrate the importance of character segmentation for achieving an accurate OCR.

Nuclear imaging using Fuji Computed Radiography

International Nuclear Information System (INIS)

Yodono, Hiraku; Tarusawa, Nobuko; Katto, Keiichi; Miyakawa, Takayoshi; Watanabe, Sadao; Shinozaki, Tatsuyo

1988-01-01

We studied the feasibility of the Fuji Computed Radiography system (FCR) in nuclear medicine. The basic principle of the system is the conversion of the X-ray energy pattern into digital signals utilizing scanning laser stimulated luminescence. A Rollo phantom filled with 12 mCi of Tc-99m pertechnetate was used in this study. In imaging by the FCR, a low energy high resolution parallel hole collimator for a gamma camera was placed over the phantom and photons through the collimator were stored on a single imaging plate (IP) or 3 IPs covered by the lead plate, 0.3 mm in thickness. For imaging, it took 30 minutes by a single IP and 20 minutes by 3 IPs with the lead plate respectively. Each image of the phantom by the FCR was compared with that of obtained by a gamma camera. The image by a single IP was inferior in quality than that of by a gamma camera. However using 3 IPs with the lead plate, same quality image as by a gamma camera was obtained. The image by 3 IPs is similar to that of by 3 IPs with the lead plate. Based on the results, we performed liver and lung imaging by FCR using 3 IPs. The imaging time is twenty minutes. The images obtained with FCR are as good as the scinticamera image. However it has two major flawes in that the sensitivity is poor and the imaging time is long. Furthermore, at present this method can only be employed for static imaging. However we feel that future improvements in the FCR system will overcome these problems. (author)

Rapid small-angle X-ray diffraction of a tonically contracting molluscan smooth muscle recorded with imaging plates

International Nuclear Information System (INIS)

Tajima, Y.; Okada, K.; Yoshida, O.; Seto, T.; Amemiya, Y.

1989-01-01

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 4 kg m -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. (orig.)

Evaluation of Bone Atrophy After Treatment of Forearm Fracture Using Nonlinear Finite Element Analysis: A Comparative Study of Locking Plates and Conventional Plates.

Science.gov (United States)

Matsuura, Yusuke; Rokkaku, Tomoyuki; Suzuki, Takane; Thoreson, Andrew Ryan; An, Kai-Nan; Kuniyoshi, Kazuki

2017-08-01

Forearm diaphysis fractures are usually managed by open reduction internal fixation. Recently, locking plates have been used for treatment. In the long-term period after surgery, some patients present with bone atrophy adjacent to the plate. However, a comparison of locking and conventional plates as a cause of atrophy has not been reported. The aim of this study was to investigate long-term bone atrophy associated with use of locking and conventional plates for forearm fracture treatment. In this study we included 15 patients with forearm fracture managed by either locking or conventional plates and with more than 5 years of follow-up. Computed tomographic imaging of both forearms was performed to assess bone thickness and local bone mineral density and to predict bone strength without plate reinforcement based on finite element analysis. Mean patient age at surgery was 48.0 years. Eight patients underwent reduction with fixed locking plates and were followed up for a mean of 79.5 months; the remaining 7 patients were treated with conventional plates and were followed up for a mean of 105.0 months. Compared with the conventional plate group, the locking plate group had the same fractured limb-contralateral limb ratio of cortex bone thickness, but had significantly lower ratios of mineral density adjacent to the plate and adjusted bone strength. This study demonstrated bone atrophy after locking plate fixation for forearm fractures. Treatment plans for forearm fracture should take into consideration the impact of bone atrophy long after plate fixation. Therapeutic IV. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Image characterization of computed radiography

International Nuclear Information System (INIS)

Candeias, Janaina P.; Saddock, Aline; Oliveira, Davi F.; Lopes, Ricardo T.

2007-01-01

The digital radiographic image became a reality as of the 80's decade. Since then, several works have been developed with the aim of reducing the exposure time to ionizing radiation obtaining in this way an excellent image quality with a minimum exposure. In the Computerized Radiography, the conventional film is substituted for Image Plate (IP) which consists of a radiosensitive layer of phosphor crystals on a polyester backing plate. The unique design makes it reusable and easy to handle. When exposed, the IP accumulates and stores the irradiated radioactive energy. In order to qualify a computerized radiography system it is necessary to evaluate the Image Plate. In this work it was performed a series of experimental procedures with the aim of evaluating the responses characteristics for different plates. For this purpose it was used a computerized radiographic system CR Tower Scanner - GE, with three different types of IPs, all of them manufactured by GE, whose nomenclatures are IPC, IPX and IPS. It was used the Rhythm Acquire and Review programs for image acquisition and treatment, respectively. (author)

The MAO NASU Plate Archive: ``observations in the past'' of minor planets

Science.gov (United States)

Sergeeva, T. P.; Golovnya, V. V.; Sergeev, A. V.

2005-06-01

The Plate Archive of the Main Astronomical Observatory of the National Academy of Sciences of Ukraine (MAO NASU) includes 20 thousands of direct sky area plates, which have been taken for various astronomical projects during the period of about 50 years. Those plates contain more then hundred thousand images of minor planets with magnitude up to 16.7m. About 10% of minor planets, which may be found on our archive plates were firstly discovered after the time when plates have been taken. So, we can rediscovery them due to the so-called ``observations in the past''. In the paper the criteria for choose of objects and methods of their search, identification, and determination of their position are discussed. First results of the search for potentially hazardous asteroids in the MAO plate archive are presented.

Faulting and hydration of the Juan de Fuca plate system

Science.gov (United States)

Nedimović, Mladen R.; Bohnenstiehl, DelWayne R.; Carbotte, Suzanne M.; Pablo Canales, J.; Dziak, Robert P.

2009-06-01

Multichannel seismic observations provide the first direct images of crustal scale normal faults within the Juan de Fuca plate system and indicate that brittle deformation extends up to ~ 200 km seaward of the Cascadia trench. Within the sedimentary layering steeply dipping faults are identified by stratigraphic offsets, with maximum throws of 110 ± 10 m found near the trench. Fault throws diminish both upsection and seaward from the trench. Long-term throw rates are estimated to be 13 ± 2 mm/kyr. Faulted offsets within the sedimentary layering are typically linked to larger offset scarps in the basement topography, suggesting reactivation of the normal fault systems formed at the spreading center. Imaged reflections within the gabbroic igneous crust indicate swallowing fault dips at depth. These reflections require local alteration to produce an impedance contrast, indicating that the imaged fault structures provide pathways for fluid transport and hydration. As the depth extent of imaged faulting within this young and sediment insulated oceanic plate is primarily limited to approximately Moho depths, fault-controlled hydration appears to be largely restricted to crustal levels. If dehydration embrittlement is an important mechanism for triggering intermediate-depth earthquakes within the subducting slab, then the limited occurrence rate and magnitude of intraslab seismicity at the Cascadia margin may in part be explained by the limited amount of water imbedded into the uppermost oceanic mantle prior to subduction. The distribution of submarine earthquakes within the Juan de Fuca plate system indicates that propagator wake areas are likely to be more faulted and therefore more hydrated than other parts of this plate system. However, being largely restricted to crustal levels, this localized increase in hydration generally does not appear to have a measurable effect on the intraslab seismicity along most of the subducted propagator wakes at the Cascadia margin.

Public Narratives under Intensified Market Conditions: Chile as a Critical Case

Science.gov (United States)

Santori, Diego

2018-01-01

This paper aims to extend existing theorisations around the notion of public narratives by analysing their regulatory effects under intensified market conditions. My analysis suggests that public narratives constitute a liminal space, one that it is not exclusively real or imaginary, factual or normative, but that simultaneously affects and is…

Reduced risk of heart failure with intensified multifactorial intervention in individuals with type 2 diabetes and microalbuminuria

DEFF Research Database (Denmark)

Oellgaard, Jens; Gæde, Peter; Rossing, Peter

2018-01-01

of hospitalisation for heart failure. METHODS: One hundred and sixty individuals were randomised to conventional or intensified multifactorial intervention, using sealed envelopes. The trial was conducted using the Prospective, Randomised, Open, Blinded Endpoints (PROBE) design. After 7.8 years, all individuals were......AIMS/HYPOTHESIS: In type 2 diabetes mellitus, heart failure is a frequent, potentially fatal and often forgotten complication. Glucose-lowering agents and adjuvant therapies modify the risk of heart failure. We recently reported that 7.8 years of intensified compared with conventional...... offered intensified therapy and the study continued as an observational follow-up study for an additional 13.4 years. Heart-failure hospitalisations were adjudicated from patient records by an external expert committee blinded for treatment allocation. Event rates were compared using a Cox regression...

Edge effects in four-point direct current potential drop measurements on metal plates

International Nuclear Information System (INIS)

Lu, Y; Bowler, N; Bowler, J R; Huang, Y

2009-01-01

Four-point direct current potential drop (DCPD) measurements are commonly used to measure the conductivity (or resistivity) of semiconductors and ferrous or non-ferrous metals. The measured electrical potential difference is often interpreted in terms of analytic expressions developed for large plates that are either 'thin' or 'thick' relative to the probe length. It is well known that the presence of the back surface of a plate leads to a solution expressed in terms of an infinite series representing the current source and its images. This approach can be generalized to account for multiple surfaces in order to obtain a solution for a finite plate, but convergence of the series is poor when the plate dimensions are similar to or smaller than the separation of the current injection and extraction points. Here, Fourier series representations of the infinite sums are obtained. It is shown that the Fourier series converge with many fewer terms than the series obtained from image theory, for plates with dimensions similar to or smaller than the separation of the current injection and extraction points. Comparing calculated results for the potential drop obtained by a four-point probe centred on finite plates of varying dimension, with those for a probe in contact with a large (laterally infinite) plate, estimates are given of the uncertainty due to edge effects in measurements on small plates interpreted using analytic formulae developed for large plates. It is also shown that these uncertainties due to edge effects are reduced, for a given plate size, if the probe pick-up points are moved closer to the current injection points, rather than adopting the common arrangement in which the four probe points are equally spaced. Calculated values of DCPD are compared with experimental data taken on aluminium and spring-steel plates of various sizes and excellent agreement is obtained.

Edge effects in four-point direct current potential drop measurements on metal plates

Science.gov (United States)

Lu, Y.; Bowler, N.; Bowler, J. R.; Huang, Y.

2009-07-01

Four-point direct current potential drop (DCPD) measurements are commonly used to measure the conductivity (or resistivity) of semiconductors and ferrous or non-ferrous metals. The measured electrical potential difference is often interpreted in terms of analytic expressions developed for large plates that are either 'thin' or 'thick' relative to the probe length. It is well known that the presence of the back surface of a plate leads to a solution expressed in terms of an infinite series representing the current source and its images. This approach can be generalized to account for multiple surfaces in order to obtain a solution for a finite plate, but convergence of the series is poor when the plate dimensions are similar to or smaller than the separation of the current injection and extraction points. Here, Fourier series representations of the infinite sums are obtained. It is shown that the Fourier series converge with many fewer terms than the series obtained from image theory, for plates with dimensions similar to or smaller than the separation of the current injection and extraction points. Comparing calculated results for the potential drop obtained by a four-point probe centred on finite plates of varying dimension, with those for a probe in contact with a large (laterally infinite) plate, estimates are given of the uncertainty due to edge effects in measurements on small plates interpreted using analytic formulae developed for large plates. It is also shown that these uncertainties due to edge effects are reduced, for a given plate size, if the probe pick-up points are moved closer to the current injection points, rather than adopting the common arrangement in which the four probe points are equally spaced. Calculated values of DCPD are compared with experimental data taken on aluminium and spring-steel plates of various sizes and excellent agreement is obtained.

Correlation potential of a test ion near a strongly charged plate.

Science.gov (United States)

Lu, Bing-Sui; Xing, Xiangjun

2014-03-01

We analytically calculate the correlation potential of a test ion near a strongly charged plate inside a dilute m:-n electrolyte. We do this by calculating the electrostatic Green's function in the presence of a nonlinear background potential, the latter having been obtained using the nonlinear Poisson-Boltzmann theory. We consider the general case where the dielectric constants of the plate and the electrolyte are distinct. The following generic results emerge from our analyses: (1) If the distance to the plate Δz is much larger than a Gouy-Chapman length, the plate surface will behave effectively as an infinitely charged surface, and the dielectric constant of the plate effectively plays no role. (2) If Δz is larger than a Gouy-Chapman length but shorter than a Debye length, the correlation potential can be interpreted in terms of an image charge that is three times larger than the source charge. This behavior is independent of the valences of the ions. (3) The Green's function vanishes inside the plate if the surface charge density is infinitely large; hence the electrostatic potential is constant there. In this respect, a strongly charged plate behaves like a conductor plate. (4) If Δz is smaller than a Gouy-Chapman length, the correlation potential is dominated by the conventional image charge due to the dielectric discontinuity at the interface. (5) If Δz is larger than a Debye length, the leading order behavior of the correlation potential will depend on the valences of the ions in the electrolyte. Furthermore, inside an asymmetric electrolyte, the correlation potential is singly screened, i.e., it undergoes exponential decay with a decay width equal to the Debye length.