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Sample records for pinhole image-formation process

  1. Computation of 2-D pinhole image-formation process of large-scale furnaces using the discrete ordinates method

    CERN Document Server

    Li Hong; Lu Ji Dong; Zheng Chu Guan

    2003-01-01

    In most of the discrete ordinate schemes (DOS) reported in the literature, the discrete directions are fixed, and unable to be arbitrarily adjusted; therefore, it is difficult to employ these schemes to calculate the radiative energy image-formation of pulverized-coal furnaces. On the basis of a new DOS, named the discrete ordinate scheme with (an) infinitely small weight(s), which was recently proposed by the authors, a novel algorithm for computing the pinhole image-formation process is developed in this work. The performance of this algorithm is tested, and is found to be also suitable for parallel computation.

  2. Computation of 2-D pinhole image-formation process of large-scale furnaces using the discrete ordinates method

    International Nuclear Information System (INIS)

    Li Hongshun; Zhou Huaichun; Lu Jidong; Zheng Chuguang

    2003-01-01

    In most of the discrete ordinate schemes (DOS) reported in the literature, the discrete directions are fixed, and unable to be arbitrarily adjusted; therefore, it is difficult to employ these schemes to calculate the radiative energy image-formation of pulverized-coal furnaces. On the basis of a new DOS, named the discrete ordinate scheme with (an) infinitely small weight(s), which was recently proposed by the authors, a novel algorithm for computing the pinhole image-formation process is developed in this work. The performance of this algorithm is tested, and is found to be also suitable for parallel computation

  3. Single molecule image formation, reconstruction and processing: introduction.

    Science.gov (United States)

    Ashok, Amit; Piestun, Rafael; Stallinga, Sjoerd

    2016-07-01

    The ability to image at the single molecule scale has revolutionized research in molecular biology. This feature issue presents a collection of articles that provides new insights into the fundamental limits of single molecule imaging and reports novel techniques for image formation and analysis.

  4. Near-infrared image formation and processing for the extraction of hand veins

    Science.gov (United States)

    Bouzida, Nabila; Hakim Bendada, Abdel; Maldague, Xavier P.

    2010-10-01

    The main objective of this work is to extract the hand vein network using a non-invasive technique in the near-infrared region (NIR). The visualization of the veins is based on a relevant feature of the blood in relation with certain wavelengths of the electromagnetic spectrum. In the present paper, we first introduce the image formation in the NIR spectral band. Then, the acquisition system will be presented as well as the method used for the image processing in order to extract the vein signature. Extractions of this pattern on the finger, on the wrist and on the dorsal hand are achieved after exposing the hand to an optical stimulation by reflection or transmission of light. We present meaningful results of the extracted vein pattern demonstrating the utility of the method for a clinical application like the diagnosis of vein disease, of primitive varicose vein and also for applications in vein biometrics.

  5. Effect of the diameter and depth of pinholes on surface characteristics in the DC pulse plasma nitriding process

    International Nuclear Information System (INIS)

    Calahonra, M.C.G; Egidi, D.A; Svoboda, H; Corengia, P

    2006-01-01

    The ion nitriding treatment is a process widely used in steel alloys to improve the material's properties; such as surface hardness, resistance to wear, fatigue life and resistance to corrosion. But geometric changes in the components can produce during the nitriding process different effects on the behavior of the plasma, such as local variations in the electric field, an empty cathode effect, etc. These in turn can affect among other factors the local temperature and therefore the kinetics of the process, generating variations in the compound layer thicknesses and zone of diffusion, and micro-hardness profile. These heterogeneities limit the effectiveness of the plasma nitriding process, where control and duplication of the surface modification are most important. This work aims to study the effect of the geometry of the pieces treated with ionic nitriding, especially the effect of the orifices. An understanding of the operating mechanisms is sought in order to predict the development of the compound layer and zone of diffusion inside the pinholes. A series of orifices with different diameters and depths were machine made in AISI 4140 quenched and tempered cylindrical steel test pieces. The diameters analyzed were 2, 4, 6, 10 and 12 mm, while the depths studied were 3, 8 and 15 mm, resulting in 15 different configurations. The samples were nitrided by DC-pulse plasma in an industrial reactor, using a mixture of 75% H 2 - 25% N 2 , during 15 hours at a temperature of 500 o C. The nitrided test pieces were characterized with transverse sections using optic and scanning electron microscopy and Vickers micro-hardness profiles, measuring the thicknesses of white layer and zone of diffusion on the wall and base of the orifices. The results show that the sizes of the pinholes made in AISI 4140 steel greatly influence the uniformity and continuity of the compound layers and zones of diffusion. 'Critical diameters' for pinholes were also defined, underneath which the

  6. Trends in the electronic X-ray image formation and processing

    International Nuclear Information System (INIS)

    Meyer-Ebrecht, D.; Spiesberger, W.

    1976-01-01

    A report is given on the technological progress in components for the electronic imaging and reproduction in X-ray diagnostics which could enable the partial replacement of radiophotography. Furthermore, electronic post processing methods, in particular in tomography, are reviewed. (ORU) [de

  7. Process of the x-ray image formation, (2). The limit to recognize a simple figure, (2)

    Energy Technology Data Exchange (ETDEWEB)

    Mitsuta, H [Osaka City Univ. (Japan). Hospital

    1980-03-01

    In recent year, X-ray photographs can be obtained by very low dose with high sensitivity photographic system. Such very low dose makes the image quality inferior because of the fluctuation of X-ray quanta so called ''quantum noise''. The process of the X-ray image formation was evaluated from a point of view that the X-ray images are formed by the accumulation of X-ray quanta distributed randomly. And the condition that the image of a simple-shaped small object can be recognized into background quanta was investigated. Under the assumption that the quanta absorbed by an object are N sub(s) and that the average number of background quanta per area which is in the same projected area of the object is N sub(b), the condition that N sub(s) is recognizable in background is mathematically led to the following formula: N sub(s) > 4(..sqrt..N sub(b) + 1). Then the validity of this formula was experimentally shown using a computer and a simulation system by a gamma camera.

  8. Contrast image formation based on thermodynamic approach and surface laser oxidation process for optoelectronic read-out system

    Science.gov (United States)

    Scherbak, Aleksandr; Yulmetova, Olga

    2018-05-01

    A pulsed fiber laser with the wavelength 1.06 μm was used to treat titanium nitride film deposited on beryllium substrates in the air with intensities below an ablation threshold to provide oxide formation. Laser oxidation results were predicted by the chemical thermodynamic method and confirmed by experimental techniques (X-ray diffraction). The developed technology of contrast image formation is intended to be used for optoelectronic read-out system.

  9. Virtual pinhole confocal microscope

    Energy Technology Data Exchange (ETDEWEB)

    George, J.S.; Rector, D.M.; Ranken, D.M. [Los Alamos National Lab., NM (United States). Biophysics Group; Peterson, B. [SciLearn Inc. (United States); Kesteron, J. [VayTech Inc. (United States)

    1999-06-01

    Scanned confocal microscopes enhance imaging capabilities, providing improved contrast and image resolution in 3-D, but existing systems have significant technical shortcomings and are expensive. Researchers at Los Alamos National Laboratory have developed a novel approach--virtual pinhole confocal microscopy--that uses state of the art illumination, detection, and data processing technologies to produce an imager with a number of advantages: reduced cost, faster imaging, improved efficiency and sensitivity, improved reliability and much greater flexibility. Work at Los Alamos demonstrated proof of principle; prototype hardware and software have been used to demonstrate technical feasibility of several implementation strategies. The system uses high performance illumination, patterned in time and space. The authors have built functional confocal imagers using video display technologies (LCD or DLP) and novel scanner based on a micro-lens array. They have developed a prototype system for high performance data acquisition and processing, designed to support realtime confocal imaging. They have developed algorithms to reconstruct confocal images from a time series of spatially sub-sampled images; software development remains an area of active development. These advances allow the collection of high quality confocal images (in fluorescence, reflectance and transmission modes) with equipment that can inexpensively retrofit to existing microscopes. Planned future extensions to these technologies will significantly enhance capabilities for microscopic imaging in a variety of applications, including confocal endoscopy, and confocal spectral imaging.

  10. Implementation and Evaluation of Pinhole SPECT

    International Nuclear Information System (INIS)

    MacArtain Anne Marie

    2002-08-01

    The aim of this work was to implement Pinhole SPECT into a working Nuclear Medicine department. It has been reported that pinhole SPECT has been successfully performed to visualise pathology in ankle bones using gamma camera and the images were constructed using a standard filtered back-projection algorithm (Bahk YW, 1998). The objective of this study was to produce and evaluate this technique with the equipment available in the nuclear medicine department. The system performance was assessed using both the low-energy high resolution and the pinhole collimators. Phantoms constructed using capillary tubes, filled with technetium 99m (pertechnetate) were imaged in different arrays to identify possible limitations in the reconstruction software. A thyroid phantom with hot and cold inserts was also imaged. Data was acquired in ''tep-and-shoot'' mode as the camera was rotated 180 degrees or 360 degrees around the phantom. Images were reconstructed using standard parallel back-projection algorithm and a weighted backprojection algorithm (Nowak). An attempt was made to process images of the phantom in Matlab using the Iradon function modified by application of a cone-beam type algorithm (Feldkamp L, 1984). Visual comparison of static images between the pinhole and the LEHR collimators showed the expected improved spatial resolution of the pinhole images. Pinhole SPECT images should be reconstructed using the appropriate cone beam algorithm. However, it was established that reconstructing pinhole SPECT images using a standard parallel backprojection algorithm yielded results which were deemed to be clinically useful. The Nowak algorithm results were a distinct improvement on those achieved with the parallel backprojection algorithm. Likewise the results from the cone beam algorithm were better than the former but not as good as those obtained from the Nowak algorithm. This was due to the fact that the cone beam algorithm did not include a weighting factor. Implementation

  11. Deep learning for SAR image formation

    Science.gov (United States)

    Mason, Eric; Yonel, Bariscan; Yazici, Birsen

    2017-04-01

    The recent success of deep learning has lead to growing interest in applying these methods to signal processing problems. This paper explores the applications of deep learning to synthetic aperture radar (SAR) image formation. We review deep learning from a perspective relevant to SAR image formation. Our objective is to address SAR image formation in the presence of uncertainties in the SAR forward model. We present a recurrent auto-encoder network architecture based on the iterative shrinkage thresholding algorithm (ISTA) that incorporates SAR modeling. We then present an off-line training method using stochastic gradient descent and discuss the challenges and key steps of learning. Lastly, we show experimentally that our method can be used to form focused images in the presence of phase uncertainties. We demonstrate that the resulting algorithm has faster convergence and decreased reconstruction error than that of ISTA.

  12. Relationship of college student characteristics and inquiry-based geometrical optics instruction to knowledge of image formation with light-ray tracing

    Science.gov (United States)

    Isik, Hakan

    the acquisition, development, and identification of reliable measures of optics concepts, processes, types of knowledge, and specific optics understanding (i.e., pinhole, plane-mirror). Future research should focus on the identification of the more critical concepts such as changes in size and sharpness of pinhole images, image observation, image formation in general, and image formation and observation in parallel mirrors. Future research can be conducted with a larger set of participants so as to compare different instructional methods and address instructional deficiencies using more efficient statistical methods. Comparative studies can be conducted to investigate the relations of various instructional strategies on student conceptions of optics.

  13. Graphic design of pinhole cameras

    Science.gov (United States)

    Edwards, H. B.; Chu, W. P.

    1979-01-01

    The paper describes a graphic technique for the analysis and optimization of pinhole size and focal length. The technique is based on the use of the transfer function of optical elements described by Scott (1959) to construct the transfer function of a circular pinhole camera. This transfer function is the response of a component or system to a pattern of lines having a sinusoidally varying radiance at varying spatial frequencies. Some specific examples of graphic design are presented.

  14. Nano-displacement measurement based on virtual pinhole confocal method

    International Nuclear Information System (INIS)

    Li, Long; Kuang, Cuifang; Xue, Yi; Liu, Xu

    2013-01-01

    A virtual pinhole confocal system based on charge-coupled device (CCD) detection and image processing techniques is built to measure axial displacement with 10 nm resolution, preeminent flexibility and excellent robustness when facing spot drifting. Axial displacement of the sample surface is determined by capturing the confocal laser spot using a CCD detector and quantifying the energy collected by programmable virtual pinholes. Experiments indicate an applicable measuring range of 1000 nm (Gaussian fitting r = 0.9902) with a highly linear range of 500 nm (linear fitting r = 0.9993). A concentric subtraction algorithm is introduced to further enhance resolution. Factors affecting measuring precision, sensitivity and signal-to-noise ratio are discussed using theoretical deductions and diffraction simulations. The virtual pinhole technique has promising applications in surface profiling and confocal imaging applications which require easily-customizable pinhole configurations. (paper)

  15. Diffraction phase microscopy realized with an automatic digital pinhole

    Science.gov (United States)

    Zheng, Cheng; Zhou, Renjie; Kuang, Cuifang; Zhao, Guangyuan; Zhang, Zhimin; Liu, Xu

    2017-12-01

    We report a novel approach to diffraction phase microscopy (DPM) with automatic pinhole alignment. The pinhole, which serves as a spatial low-pass filter to generate a uniform reference beam, is made out of a liquid crystal display (LCD) device that allows for electrical control. We have made DPM more accessible to users, while maintaining high phase measurement sensitivity and accuracy, through exploring low cost optical components and replacing the tedious pinhole alignment process with an automatic pinhole optical alignment procedure. Due to its flexibility in modifying the size and shape, this LCD device serves as a universal filter, requiring no future replacement. Moreover, a graphic user interface for real-time phase imaging has been also developed by using a USB CMOS camera. Experimental results of height maps of beads sample and live red blood cells (RBCs) dynamics are also presented, making this system ready for broad adaption to biological imaging and material metrology.

  16. From Pinholes to Black Holes

    Energy Technology Data Exchange (ETDEWEB)

    Fenimore, Edward E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-10-06

    Pinhole photography has made major contributions to astrophysics through the use of “coded apertures”. Coded apertures were instrumental in locating gamma-ray bursts and proving that they originate in faraway galaxies, some from the birth of black holes from the first stars that formed just after the big bang.

  17. Effect of pinhole shape on projection resolution

    International Nuclear Information System (INIS)

    Johnson, L C; Metzler, S D; Moore, S C

    2016-01-01

    We are designing a dual-resolution pre-clinical SPECT system based on square-pinhole apertures for use in applications with a small field-of-view (FOV), such as cardiac imaging of mice. Square pinholes allow for increased sensitivity due to more efficient projection tiling on the detector compared to circular pinholes. Aperture fabrication techniques cannot produce a perfect square, giving the square pinholes some amount of roundedness at the corners. This work investigates how this roundedness affects the physical properties of projection images in terms of spatial resolution. Different pinhole full-acceptance angles and roundedness values were simulated. To facilitate a fair comparison, properties of the non-square pinholes were manipulated to yield pinholes with approximately the same sensitivity (to within 0.1%) and FOV (to within 0.5%) as those of the square pinholes, subsequently referred to as matched apertures. The aperture size (flat-to-flat edge length) of each non-square aperture was increased until its sensitivity was approximately equal to that of the square pinhole. Next, the full acceptance angle was increased until the FOV of each non-square aperture was approximately equivalent to that of the square pinhole. Sensitivity was calculated to include both the geometric and penetrative sensitivity of a point source, as well as the packing faction of the multi-pinhole collimator. Using the sensitivity-matched and FOV-matched apertures, spatial resolution was estimated. For the 0.3 mm, 0.5 mm, and 1 mm edge-length square apertures studied, the full-width at half-maximum widened as pinhole shape changed from square to circle, while full-width tenth-maximum showed little change. These results indicate that a perfect square pinhole shape is more desirable than a rounded-square pinhole with regard to spatial resolution when sensitivity and FOV-matched pinholes are compared. (paper)

  18. Stereo Pinhole Camera: Assembly and experimental activities

    Directory of Open Access Journals (Sweden)

    Gilmário Barbosa Santos

    2015-05-01

    Full Text Available This work describes the assembling of a stereo pinhole camera for capturing stereo-pairs of images and proposes experimental activities with it. A pinhole camera can be as sophisticated as you want, or so simple that it could be handcrafted with practically recyclable materials. This paper describes the practical use of the pinhole camera throughout history and currently. Aspects of optics and geometry involved in the building of the stereo pinhole camera are presented with illustrations. Furthermore, experiments are proposed by using the images obtained by the camera for 3D visualization through a pair of anaglyph glasses, and the estimation of relative depth by triangulation is discussed.

  19. Variability in DMSA reporting following urinary tract infection in children: pinhole, planar, and pinhole with planar

    International Nuclear Information System (INIS)

    Rossleigh, M.A.; Christian, C.L.; Craig, J.C.; Howman-Giles, R.B.; Grunewald, S.

    2004-01-01

    Purpose: To determine whether the provision of DMSA images obtained by pinhole collimation reduces inter-observer variability of reporting compared with planar DMSA images alone. Methods: One hundred consecutive DMSA images were independently interpreted three times (pinhole alone, planar alone, pinhole and planar) by four participating nuclear medicine specialists from different departments and in random order. The presence or absence of renal parenchymal abnormality was classified using the modified four level grading system of Goldraich with mean values for the 6 comparisons reported. Results: The proportion of DMSA images interpreted as abnormal was 31% for planar, 34% for pinhole and 33% for planar with pinhole. Agreement was 89% for planar alone, 89% for pinhole alone and 90% for planar with pinhole, with kappa values 0.74, 0.75 and 0.80 respectively for the normal-abnormal scan classification of individual children. These results did not vary appreciably whether interpretation of patients, kidneys or kidney zones was compared. Reasons for disagreement in reporting included different interpretations of 'abnormalities' as normal anatomical variations (splenic impression, fetal lobulation, duplex collecting systems, column of Bertin) or true parenchymal abnormalities, different adjustments in thresholds for reporting abnormality when images were technically suboptimal, different weighting given to pinhole and planar images when both were provided, and error. Conclusion: Four experienced nuclear medicine physicians showed substantial agreement in the interpretation of planar alone, pinhole alone and planar with pinhole DMSA images, but the provision of both sets of images, planar and pinhole, did not reduce variability. (authors)

  20. An investigation of inconsistent projections and artefacts in multi-pinhole SPECT with axially aligned pinholes

    International Nuclear Information System (INIS)

    Kench, P L; Meikle, S R; Lin, J; Gregoire, M C

    2011-01-01

    Multiple pinholes are advantageous for maximizing the use of the available field of view (FOV) of compact small animal single photon emission computed tomography (SPECT) detectors. However, when the pinholes are aligned axially to optimize imaging of extended objects, such as rodents, multiplexing of the pinhole projections can give rise to inconsistent data which leads to 'ghost point' artefacts in the reconstructed volume. A novel four pinhole collimator with a baffle was designed and implemented to eliminate these inconsistent projections. Simulation and physical phantom studies were performed to investigate artefacts from axially aligned pinholes and the efficacy of the baffle in removing inconsistent data and, thus, reducing reconstruction artefacts. SPECT was performed using a Defrise phantom to investigate the impact of collimator design on FOV utilization and axial blurring effects. Multiple pinhole SPECT acquired with a baffle had fewer artefacts and improved quantitative accuracy when compared to SPECT acquired without a baffle. The use of four pinholes positioned in a square maximized the available FOV, increased acquisition sensitivity and reduced axial blurring effects. These findings support the use of a baffle to eliminate inconsistent projection data arising from axially aligned pinholes and improve small animal SPECT reconstructions.

  1. Numerical simulation for neutron pinhole imaging in ICF

    International Nuclear Information System (INIS)

    Chen Faxin; Yang Jianlun; Wen Shuhuai

    2005-01-01

    Pinhole imaging of the neutron production in laser-driven inertial confinement fusion experiments can provide important information about performance of various capsule designs. In order to get good results in experiments, it is needed to judge performance of various pinhole designs qualitatively or quantitatively before experiment. Calculation of imaging can be simply separated into pinhole imaging and image spectral analysis. In this paper, pinhole imaging is discussed, codes for neutron pinhole imaging and image showing is programed. The codes can be used to provide theoretical foundation for pinhole designing and simulating data for image analysing. (authors)

  2. Absolute quantitative total-body small-animal SPECT with focusing pinholes

    NARCIS (Netherlands)

    Wu, C.; Van der Have, F.; Vastenhouw, B.; Dierckx, R.A.J.O.; Paans, A.M.J.; Beekman, F.J.

    2010-01-01

    Purpose: In pinhole SPECT, attenuation of the photon flux on trajectories between source and pinholes affects quantitative accuracy of reconstructed images. Previously we introduced iterative methods that compensate for image degrading effects of detector and pinhole blurring, pinhole sensitivity

  3. Improved quantification in single-pinhole and multiple-pinhole SPECT using micro-CT information

    International Nuclear Information System (INIS)

    Vanhove, Christian; Bossuyt, Axel; Defrise, Michel; Lahoutte, Tony

    2009-01-01

    The purpose of this study was to demonstrate the feasibility of accurate quantification in pinhole SPECT using micro-CT information. Pinhole SPECT scans were performed using a clinical dual-head gamma camera. Each pinhole SPECT scan was followed by a micro-CT acquisition. Functional and anatomical images were coregistered using six point sources visible with both modalities. Pinhole SPECT images were reconstructed iteratively. Attenuation correction was based on micro-CT information. Scatter correction was based on dual and triple-energy window methods. Phantom and animal experiments were performed. A phantom containing nine vials was filled with different concentrations of 99m Tc. Three vials were also filled with CT contrast agent to increase attenuation. Activity concentrations measured on the pinhole SPECT images were compared with activity concentrations measured by the dose calibrator. In addition, 11 mice were injected with 99m Tc-labelled Nanobodies. After acquiring functional and anatomical images, the animals were killed and the liver activity was measured using a gamma-counter. Activity concentrations measured on the reconstructed images were compared with activity concentrations measured with the gamma counter. The phantom experiments demonstrated an average error of -27.3 ± 15.9% between the activity concentrations measured on the uncorrected pinhole SPECT images and in the dose calibrator. This error decreased significantly to -0.1 ± 7.3% when corrections were applied for nonuniform attenuation and scatter. The animal experiment revealed an average error of -18.4 ± 11.9% between the activity concentrations measured on the uncorrected pinhole SPECT images and measured with the gamma counter. This error decreased to -7.9 ± 10.4% when attenuation and scatter correction was applied. Attenuation correction obtained from micro-CT data in combination with scatter correction allows accurate quantification in pinhole SPECT. (orig.)

  4. Transmission Electron Microscopy Physics of Image Formation

    CERN Document Server

    Kohl, Helmut

    2008-01-01

    Transmission Electron Microscopy: Physics of Image Formation presents the theory of image and contrast formation, and the analytical modes in transmission electron microscopy. The principles of particle and wave optics of electrons are described. Electron-specimen interactions are discussed for evaluating the theory of scattering and phase contrast. Also discussed are the kinematical and dynamical theories of electron diffraction and their applications for crystal-structure analysis and imaging of lattices and their defects. X-ray microanalysis and electron energy-loss spectroscopy are treated as analytical methods. Specimen damage and contamination by electron irradiation limits the resolution for biological and some inorganic specimens. This fifth edition includes discussion of recent progress, especially in the area of aberration correction and energy filtering; moreover, the topics introduced in the fourth edition have been updated. Transmission Electron Microscopy: Physics of Image Formation is written f...

  5. Optimizing renal DMSA-scintigraphy with 7-pinhole collimator

    International Nuclear Information System (INIS)

    Botsch, H.; Pottmeyer, A.; Savaser, A.; Lochner, B.; Felix, R.

    1982-01-01

    Multiple pinhole emission tomographic imaging techniques are currently being applied to imaging of organs of a limited size. The purpose of this study was to evaluate the feasibility of this technique in kidney imaging with Tcsup(99m)-DMSA. A 7-pinhole collimator having 4.5 mm. pinhole apertures was used in conjunction with a widefield camera. Left and right kidney were imaged separately. Twelve small renal cysts with a diameter of 1 to 3.5 cm. verified by US or CAT were investigated by 7-pinhole and planar scintigraphy. Eight of 12 renal cysts were identified by 7-pinhole scintigraphy whereas only one cyst was seen by planar scintigraphy. The borderline of cysts detection was 1.5 cm. in 7-pinhole tomography. Basing on these comparative studies and experiences on many patient investigations it seems reasonable to perform renal scintigraphy with 7-pinhole tomography in a routine manner. (orig.)

  6. Evaluation of penetration and scattering components in conventional pinhole SPECT: phantom studies using Monte Carlo simulation

    International Nuclear Information System (INIS)

    Deloar, Hossain M; Watabe, Hiroshi; Aoi, Toshiyuki; Iida, Hidehiro

    2003-01-01

    In quantitative pinhole SPECT, photon penetration through the collimator edges (penetration), and photon scattering by the object (object scatter) and collimator (collimator scatter) have not been investigated rigorously. Monte Carlo simulation was used to evaluate these three physical processes for different tungsten knife-edge pinhole collimators using uniform, hotspot and donut phantoms filled with 201 Tl, 99m Tc, 123 I and 131 I solutions. For the hotspot phantom, the penetration levels with respect to total counts for a 1 mm pinhole aperture were 78%, 28% and 23% for 131 I, 123 I and 99m Tc, respectively. For a 2 mm aperture, these values were 65% for 131 I, 16% for 123 I and 12% for 99m Tc. For all pinholes, 201 Tl penetration was less than 4%. The evaluated scatter (from object and collimator) with a hotspot phantom for the 1 mm pinhole was 24%, 16%, 18% and 13% for 201 Tl, 99m Tc, 123 I and 131 I, respectively. Summation of the object and collimator scatter for the uniform phantom was approximately 20% higher than that for the hotspot phantom. Significant counts due to penetration and object and collimator scatter in the reconstructed image were observed inside the core of the donut phantom. The collimator scatter can be neglected for all isotopes used in this study except for 131 I. Object scatter correction for all radionuclides used in this study is necessary and correction for the penetration contribution is necessary for all radionuclides but 201 Tl

  7. Applications of multi-pinhole gamma camera collimation to tomography and image enhancement

    International Nuclear Information System (INIS)

    Simpson, D.R.

    1981-01-01

    Recently, multi-pinhole gamma camera collimation has been introduced in the field of emission tomography. This collimation process simultaneously produces several images covering a limited angular range, which may then be recombined to obtain tomographic slices of the object imaged. This study has investigated a possible method for improving the images obtained by this technique by two multi-pinhole views taken 90 0 apart. During the course of this work, multi-pinhole collimation was also applied to in vivo imaging of the disintegration of tablets. Collimmators were designed and built both for tomography and imaging tablet disintegration, and computer programs were written to reconstruct the images by simple backprojection and by filtered backprojection. The use of multi-pinhole collimators to image the disintegration of tablets in vivo was clearly demonstrated. Phantom tests done in vitro were capable of imaging defects as small as 5 mm 2 , while images made with real tablets both in vitro and in vivo readily showed the onset and progress of the tablet disintegration. Further experiments are planned using this technique to measure gastric emptying times disintegration times of various tablet formulations. Limitations of multi-pinhole technique included problems such as limited ranges of viewing and artifacts introduced due to incomplete sampling

  8. Electric Field Reconstruction in the Image Plane of a High-Contrast Coronagraph Using a Set of Pinholes Around the Lyot Plane

    Science.gov (United States)

    Giveon, Amir; Kern, Brian; Shaklan, Stuart; Wallace, Kent; Noecker, Charley

    2012-01-01

    The pair-wise estimation has been used now on various testbeds with different coronagraphs with the best contrast results to date. Pinholes estimate has been implemented and ready to be tested in closed loop correction. Pinholes estimate offers an independent method. We hope to improve the calibration process to gain better estimates.

  9. Collimated proton acceleration in light sail regime with a tailored pinhole target

    Energy Technology Data Exchange (ETDEWEB)

    Wang, H. Y.; Zepf, M. [Helmholtz Institute Jena, Fröbelstieg 3, 07743 Jena (Germany); Yan, X. Q. [State Key Laboratory of Nuclear Physics and Technology and Key Lab of High Energy Density Physics Simulation, CAPT, Peking University, Beijing 100871 (China)

    2014-06-15

    A scheme for producing collimated protons from laser interactions with a diamond-like-carbon + pinhole target is proposed. The process is based on radiation pressure acceleration in the multi-species light-sail regime [B. Qiao et al., Phys. Rev. Lett. 105, 155002 (2010); T. P. Yu et al., Phys. Rev. Lett. 105, 065002 (2010)]. Particle-in-cell simulations demonstrate that transverse quasistatic electric field at TV/m level can be generated in the pinhole. The transverse electric field suppresses the transverse expansion of protons effectively, resulting in a higher density and more collimated proton beam compared with a single foil target. The dependence of the proton beam divergence on the parameters of the pinhole is also investigated.

  10. Collimated proton acceleration in light sail regime with a tailored pinhole target

    International Nuclear Information System (INIS)

    Wang, H. Y.; Zepf, M.; Yan, X. Q.

    2014-01-01

    A scheme for producing collimated protons from laser interactions with a diamond-like-carbon + pinhole target is proposed. The process is based on radiation pressure acceleration in the multi-species light-sail regime [B. Qiao et al., Phys. Rev. Lett. 105, 155002 (2010); T. P. Yu et al., Phys. Rev. Lett. 105, 065002 (2010)]. Particle-in-cell simulations demonstrate that transverse quasistatic electric field at TV/m level can be generated in the pinhole. The transverse electric field suppresses the transverse expansion of protons effectively, resulting in a higher density and more collimated proton beam compared with a single foil target. The dependence of the proton beam divergence on the parameters of the pinhole is also investigated

  11. Applications of multi-pinhole gamma camera collimation to tomography and image enhancement

    Science.gov (United States)

    Simpson, D. R.

    1981-06-01

    Multi-pinhole gamma camera collimation was introduced in the field of emission tomography. This collimation process simultaneously produces several images covering a limited angular range, which may then be recombined to obtain tomographic slices of the object imaged. A possible method for improving the images obtained by this technique by combining two multi-pinhole views taken 90 deg apart was investigated. Collimators were designed and built both for tomography and imaging tablet disintegration, and computer programs were written to reconstruct the images by simple backprojection and by filtered backprojection. The use of multi-pinhole collimators to image the disintegration of tablets in vivo was clearly demonstrated. Phantom tests done in vitro were capable of imaging defects as small as 5 sq mm, while images made with real tablets both in vitro and in vivo readily showed the onset and progress of the tablet disintegration.

  12. High-resolution tomography of positron emitters with clustered pinhole SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Goorden, Marlies C; Beekman, Freek J [Section of Radiation Detection and Medical Imaging, Applied Sciences, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands)], E-mail: m.c.goorden@tudelft.nl

    2010-03-07

    State-of-the-art small-animal single photon emission computed tomography (SPECT) enables sub-half-mm resolution imaging of radio-labelled molecules. Due to severe photon penetration through pinhole edges, current multi-pinhole SPECT is not suitable for high-resolution imaging of photons with high energies, such as the annihilation photons emitted by positron emitting tracers (511 keV). To deal with this edge penetration, we introduce here clustered multi-pinhole SPECT (CMP): each pinhole in a cluster has a narrow opening angle to reduce photon penetration. Using simulations, CMP is compared with (i) a collimator with traditional pinholes that is currently used for sub-half-mm imaging of SPECT isotopes (U-SPECT-II), and (ii), like (i) but with collimator thickness adapted to image high-energy photons (traditional multi-pinhole SPECT, TMP). At 511 keV, U-SPECT-II is able to resolve the 0.9 mm rods of an iteratively reconstructed Jaszczak-like capillary hot rod phantom, and while TMP only leads to small improvements, CMP can resolve rods as small as 0.7 mm. Using a digital tumour phantom, we show that CMP resolves many details not assessable with standard USPECT-II and TMP collimators. Furthermore, CMP makes it possible to visualize uptake of positron emitting tracers in sub-compartments of a digital mouse striatal brain phantom. This may open up unique possibilities for analysing processes such as those underlying the function of neurotransmitter systems. Additional potential of CMP may include (i) the imaging of other high-energy single-photon emitters (e.g. I-131) and (ii) localized imaging of positron emitting tracers simultaneously with single photon emitters, with an even better resolution than coincidence PET.

  13. Closure phenomena in pinholes irradiated by Nd laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Auerbach, J.M.; Holmes, N.C.; Hunt, J.T.; Linford, G.J.

    1979-07-15

    An experimental investigation has been made on plasma closure in pinholes irradiated by Nd glass laser pulses; 300--500-..mu..m diam pinholes of various materials and thicknesses have been irradiated by 20--100-J 300-psec FWHM pulses on the Janus laser system. Calorimetry measurements have yielded data on pinhole energy transmission and intensity loading on the periphery of the pinhole. Ultrafast streak photography measurements indicate effective closure velocities of 2--5 x 10/sup 7/ cm/sec. Scattered light measurements have shown the transmission loss through a typical spatial filter configuration to be primarily refractive in nature.

  14. Optimum Image Formation for Spaceborne Microwave Radiometer Products.

    Science.gov (United States)

    Long, David G; Brodzik, Mary J

    2016-05-01

    This paper considers some of the issues of radiometer brightness image formation and reconstruction for use in the NASA-sponsored Calibrated Passive Microwave Daily Equal-Area Scalable Earth Grid 2.0 Brightness Temperature Earth System Data Record project, which generates a multisensor multidecadal time series of high-resolution radiometer products designed to support climate studies. Two primary reconstruction algorithms are considered: the Backus-Gilbert approach and the radiometer form of the scatterometer image reconstruction (SIR) algorithm. These are compared with the conventional drop-in-the-bucket (DIB) gridded image formation approach. Tradeoff study results for the various algorithm options are presented to select optimum values for the grid resolution, the number of SIR iterations, and the BG gamma parameter. We find that although both approaches are effective in improving the spatial resolution of the surface brightness temperature estimates compared to DIB, SIR requires significantly less computation. The sensitivity of the reconstruction to the accuracy of the measurement spatial response function (MRF) is explored. The partial reconstruction of the methods can tolerate errors in the description of the sensor measurement response function, which simplifies the processing of historic sensor data for which the MRF is not known as well as modern sensors. Simulation tradeoff results are confirmed using actual data.

  15. SCIFIO: an extensible framework to support scientific image formats.

    Science.gov (United States)

    Hiner, Mark C; Rueden, Curtis T; Eliceiri, Kevin W

    2016-12-07

    No gold standard exists in the world of scientific image acquisition; a proliferation of instruments each with its own proprietary data format has made out-of-the-box sharing of that data nearly impossible. In the field of light microscopy, the Bio-Formats library was designed to translate such proprietary data formats to a common, open-source schema, enabling sharing and reproduction of scientific results. While Bio-Formats has proved successful for microscopy images, the greater scientific community was lacking a domain-independent framework for format translation. SCIFIO (SCientific Image Format Input and Output) is presented as a freely available, open-source library unifying the mechanisms of reading and writing image data. The core of SCIFIO is its modular definition of formats, the design of which clearly outlines the components of image I/O to encourage extensibility, facilitated by the dynamic discovery of the SciJava plugin framework. SCIFIO is structured to support coexistence of multiple domain-specific open exchange formats, such as Bio-Formats' OME-TIFF, within a unified environment. SCIFIO is a freely available software library developed to standardize the process of reading and writing scientific image formats.

  16. Multilayer roughness and image formation in the Schwarzschild objective

    International Nuclear Information System (INIS)

    Singh, S.; Solak, H.; Cerrina, F.

    1996-01-01

    We present a study of the effect of multilayer-surface-roughness-induced scattering in the image formation of the Schwarzschild objective (SO) used in the spectromicroscope MAXIMUM. The two mirrors comprising the SO are coated with Ru/B 4 C multilayers that have a peak reflectivity at 130 eV. We had long observed that a diffuse x-ray background surrounds the focused x-ray spot. The spatial resolution remains at 0.1 μm in spite of this. However, since a significant fraction of the flux is lost to the background, since too large an area of the sample is illuminated, and since the S/N ratio is degraded, the origins of this effect merit investigation. This diffuse background resulting from x-ray scattering at the surface of the mirrors was mapped out using bidirectional knife edge scans. Complementary surface roughness simulations were carried out with the ray-tracing program SHADOW. AFM experiments were also done to directly measure the surface roughness and power spectrum of representative multilayers. Following curve fitting, it was possible to classify Gaussian components in both the measured and simulated profiles as arising from scattering occurring at either the convex primary mirror or the concave secondary mirror. Together with geometrical analysis, these techniques permitted us to track the image formation process of an actual optical system in the presence of surface roughness. copyright 1996 American Institute of Physics

  17. Optimizing multi-pinhole SPECT geometries using an analytical model

    International Nuclear Information System (INIS)

    Rentmeester, M C M; Have, F van der; Beekman, F J

    2007-01-01

    State-of-the-art multi-pinhole SPECT devices allow for sub-mm resolution imaging of radio-molecule distributions in small laboratory animals. The optimization of multi-pinhole and detector geometries using simulations based on ray-tracing or Monte Carlo algorithms is time-consuming, particularly because many system parameters need to be varied. As an efficient alternative we develop a continuous analytical model of a pinhole SPECT system with a stationary detector set-up, which we apply to focused imaging of a mouse. The model assumes that the multi-pinhole collimator and the detector both have the shape of a spherical layer, and uses analytical expressions for effective pinhole diameters, sensitivity and spatial resolution. For fixed fields-of-view, a pinhole-diameter adapting feedback loop allows for the comparison of the system resolution of different systems at equal system sensitivity, and vice versa. The model predicts that (i) for optimal resolution or sensitivity the collimator layer with pinholes should be placed as closely as possible around the animal given a fixed detector layer, (ii) with high-resolution detectors a resolution improvement up to 31% can be achieved compared to optimized systems, (iii) high-resolution detectors can be placed close to the collimator without significant resolution losses, (iv) interestingly, systems with a physical pinhole diameter of 0 mm can have an excellent resolution when high-resolution detectors are used

  18. Estimate of energy density on CYCLOPS spatial filter pinhole structure

    International Nuclear Information System (INIS)

    Guch, S. Jr.

    1974-01-01

    The inclusion of a spatial filter between the B and C stages in CYCLOPS to reduce the effects of small-scale beam self-focusing is discussed. An estimate is made of the energy density to which the pinhole will be subjected, and the survivability of various pinhole materials and designs is discussed

  19. Proton pinhole imaging on the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Zylstra, A. B., E-mail: zylstra@lanl.gov [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Park, H.-S.; Ross, J. S.; Higginson, D. P.; Huntington, C.; Pollock, B.; Remington, B.; Rinderknecht, H. G.; Ryutov, D.; Turnbull, D.; Wilks, S. C. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Fiuza, F. [SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Frenje, J. A.; Li, C. K.; Petrasso, R. D.; Séguin, F. H. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2016-11-15

    Pinhole imaging of large (mm scale) carbon-deuterium (CD) plasmas by proton self-emission has been used for the first time to study the microphysics of shock formation, which is of astrophysical relevance. The 3 MeV deuterium-deuterium (DD) fusion proton self-emission from these plasmas is imaged using a novel pinhole imaging system, with up to five different 1 mm diameter pinholes positioned 25 cm from target-chamber center. CR39 is used as the detector medium, positioned at 100 cm distance from the pinhole for a magnification of 4 ×. A Wiener deconvolution algorithm is numerically demonstrated and used to interpret the images. When the spatial morphology is known, this algorithm accurately reproduces the size of features larger than about half the pinhole diameter. For these astrophysical plasma experiments on the National Ignition Facility, this provides a strong constraint on simulation modeling of the experiment.

  20. Research On The Measure Method Of Oblique Pinhole Parameters

    Directory of Open Access Journals (Sweden)

    Ma Yu-Zhen

    2016-01-01

    Full Text Available There are many special advantages in measuring the diameter of blind and deep holes with a capacitive probe, there are still some challenges for the measurement of a oblique pinhole parameters because the measuring device is inconvenient to stretch into the oblique pinhole exactly. A five-dimensional measurement system was adopted in the paper which included a capacitive sensor probe and a three-coordinate measuring machine to accomplish the measurement for oblique pinholes. With the help of the three-dimensional coordinates measured from the pinhole axis, we put forward a comprehensive method of combining the projection method and the least squares method together for fitting spatial straight line to obtain the optimal equation of the spacial axis. Finally, a reliable and entire measurement system was set up.

  1. Note: Diagnosing femtosecond laser-solid interactions with monochromatic Kα imager and x-ray pinhole camera

    International Nuclear Information System (INIS)

    Lin, X. X.; Li, Y. T.; Liu, F.; Du, F.; Wang, S. J.; Chen, L. M.; Zhang, L.; Zheng, Y.; Liu, X.; Liu, X. L.; Wang, Z. H.; Ma, J. L.; Wei, Z. Y.; Liu, B. C.; Zhang, J.

    2011-01-01

    An x-ray pinhole camera and a monochromatic K α imager are used to measure the interactions of intense femtosecond laser pulses with Cu foil targets. The two diagnostics give different features in the spot size and the laser energy scaling, which are resulted from different physical processes. Under our experimental conditons, the K α emission is mainly excited by the fast electrons transporting inside the cold bulk target. In contrast, the x-ray pinhole signals are dominated by the broadband thermal x-ray emission from the hot plasma at the front target surface.

  2. Accelerated 3D-OSEM image reconstruction using a Beowulf PC cluster for pinhole SPECT

    International Nuclear Information System (INIS)

    Zeniya, Tsutomu; Watabe, Hiroshi; Sohlberg, Antti; Iida, Hidehiro

    2007-01-01

    A conventional pinhole single-photon emission computed tomography (SPECT) with a single circular orbit has limitations associated with non-uniform spatial resolution or axial blurring. Recently, we demonstrated that three-dimensional (3D) images with uniform spatial resolution and no blurring can be obtained by complete data acquired using two-circular orbit, combined with the 3D ordered subsets expectation maximization (OSEM) reconstruction method. However, a long computation time is required to obtain the reconstruction image, because of the fact that 3D-OSEM is an iterative method and two-orbit acquisition doubles the size of the projection data. To reduce the long reconstruction time, we parallelized the two-orbit pinhole 3D-OSEM reconstruction process by using a Beowulf personal computer (PC) cluster. The Beowulf PC cluster consists of seven PCs connected to Gbit Ethernet switches. Message passing interface protocol was utilized for parallelizing the reconstruction process. The projection data in a subset are distributed to each PC. The partial image forward-and back-projected in each PC is transferred to all PCs. The current image estimate on each PC is updated after summing the partial images. The performance of parallelization on the PC cluster was evaluated using two independent projection data sets acquired by a pinhole SPECT system with two different circular orbits. Parallelization using the PC cluster improved the reconstruction time with increasing number of PCs. The reconstruction time of 54 min by the single PC was decreased to 10 min when six or seven PCs were used. The speed-up factor was 5.4. The reconstruction image by the PC cluster was virtually identical with that by the single PC. Parallelization of 3D-OSEM reconstruction for pinhole SPECT using the PC cluster can significantly reduce the computation time, whereas its implementation is simple and inexpensive. (author)

  3. Development of a high sensitivity pinhole type gamma camera using semiconductors for low dose rate fields

    Science.gov (United States)

    Ueno, Yuichiro; Takahashi, Isao; Ishitsu, Takafumi; Tadokoro, Takahiro; Okada, Koichi; Nagumo, Yasushi; Fujishima, Yasutake; Yoshida, Akira; Umegaki, Kikuo

    2018-06-01

    We developed a pinhole type gamma camera, using a compact detector module of a pixelated CdTe semiconductor, which has suitable sensitivity and quantitative accuracy for low dose rate fields. In order to improve the sensitivity of the pinhole type semiconductor gamma camera, we adopted three methods: a signal processing method to set the discriminating level lower, a high sensitivity pinhole collimator and a smoothing image filter that improves the efficiency of the source identification. We tested basic performances of the developed gamma camera and carefully examined effects of the three methods. From the sensitivity test, we found that the effective sensitivity was about 21 times higher than that of the gamma camera for high dose rate fields which we had previously developed. We confirmed that the gamma camera had sufficient sensitivity and high quantitative accuracy; for example, a weak hot spot (0.9 μSv/h) around a tree root could be detected within 45 min in a low dose rate field test, and errors of measured dose rates with point sources were less than 7% in a dose rate accuracy test.

  4. Fast and accurate focusing analysis of large photon sieve using pinhole ring diffraction model.

    Science.gov (United States)

    Liu, Tao; Zhang, Xin; Wang, Lingjie; Wu, Yanxiong; Zhang, Jizhen; Qu, Hemeng

    2015-06-10

    In this paper, we developed a pinhole ring diffraction model for the focusing analysis of a large photon sieve. Instead of analyzing individual pinholes, we discuss the focusing of all of the pinholes in a single ring. An explicit equation for the diffracted field of individual pinhole ring has been proposed. We investigated the validity range of this generalized model and analytically describe the sufficient conditions for the validity of this pinhole ring diffraction model. A practical example and investigation reveals the high accuracy of the pinhole ring diffraction model. This simulation method could be used for fast and accurate focusing analysis of a large photon sieve.

  5. Modeling of Pixelated Detector in SPECT Pinhole Reconstruction.

    Science.gov (United States)

    Feng, Bing; Zeng, Gengsheng L

    2014-04-10

    A challenge for the pixelated detector is that the detector response of a gamma-ray photon varies with the incident angle and the incident location within a crystal. The normalization map obtained by measuring the flood of a point-source at a large distance can lead to artifacts in reconstructed images. In this work, we investigated a method of generating normalization maps by ray-tracing through the pixelated detector based on the imaging geometry and the photo-peak energy for the specific isotope. The normalization is defined for each pinhole as the normalized detector response for a point-source placed at the focal point of the pinhole. Ray-tracing is used to generate the ideal flood image for a point-source. Each crystal pitch area on the back of the detector is divided into 60 × 60 sub-pixels. Lines are obtained by connecting between a point-source and the centers of sub-pixels inside each crystal pitch area. For each line ray-tracing starts from the entrance point at the detector face and ends at the center of a sub-pixel on the back of the detector. Only the attenuation by NaI(Tl) crystals along each ray is assumed to contribute directly to the flood image. The attenuation by the silica (SiO 2 ) reflector is also included in the ray-tracing. To calculate the normalization for a pinhole, we need to calculate the ideal flood for a point-source at 360 mm distance (where the point-source was placed for the regular flood measurement) and the ideal flood image for the point-source at the pinhole focal point, together with the flood measurement at 360 mm distance. The normalizations are incorporated in the iterative OSEM reconstruction as a component of the projection matrix. Applications to single-pinhole and multi-pinhole imaging showed that this method greatly reduced the reconstruction artifacts.

  6. Cloud Optimized Image Format and Compression

    Science.gov (United States)

    Becker, P.; Plesea, L.; Maurer, T.

    2015-04-01

    Cloud based image storage and processing requires revaluation of formats and processing methods. For the true value of the massive volumes of earth observation data to be realized, the image data needs to be accessible from the cloud. Traditional file formats such as TIF and NITF were developed in the hay day of the desktop and assumed fast low latency file access. Other formats such as JPEG2000 provide for streaming protocols for pixel data, but still require a server to have file access. These concepts no longer truly hold in cloud based elastic storage and computation environments. This paper will provide details of a newly evolving image storage format (MRF) and compression that is optimized for cloud environments. Although the cost of storage continues to fall for large data volumes, there is still significant value in compression. For imagery data to be used in analysis and exploit the extended dynamic range of the new sensors, lossless or controlled lossy compression is of high value. Compression decreases the data volumes stored and reduces the data transferred, but the reduced data size must be balanced with the CPU required to decompress. The paper also outlines a new compression algorithm (LERC) for imagery and elevation data that optimizes this balance. Advantages of the compression include its simple to implement algorithm that enables it to be efficiently accessed using JavaScript. Combing this new cloud based image storage format and compression will help resolve some of the challenges of big image data on the internet.

  7. Image formation in diagnostic X-ray equipment

    International Nuclear Information System (INIS)

    Boer, J.A. den.

    1983-01-01

    This thesis deals with a physical description of the image formation in static radiographic shadow image X-ray equipment and an analysis of the optimization of such systems. For the latter criteria have been developed that take into account all relevant physical phenomena that relate to properties of the image and the radiation exposure of the patient. The discussion of image formation results in a number of relations between the X-ray system parameters on the one hand and properties of the X-ray image on the other. The three principal aspects considered are energy transfer, modulation transfer and noise. (Auth./C.F.)

  8. An Evaluation of Pinhole Castration as an Alternative Technique for ...

    African Journals Online (AJOL)

    We evaluated pinhole castration as an alternative technique for dog population control in resource poor rural communities of Gulu, Northern Uganda. Through a campaign dubbed 'Big Fix Gulu', households in selected communities were mobilized using radio announcements, posters and school visits, to present dogs for ...

  9. COPPER PITTING CORROSION AND PINHOLE LEAKS: A CASE STUDY

    Science.gov (United States)

    Localized corrosion, or "pitting", of copper drinking water pipe continues is a problem for many water utilities and their customers. Extreme attack leads to pinhole leaks that can potentially lead to water damage, mold growth, and costly repairs for the homeowners, as well as th...

  10. Image formation and image analysis in electron microscopy

    International Nuclear Information System (INIS)

    Heel, M. van.

    1981-01-01

    This thesis covers various aspects of image formation and image analysis in electron microscopy. The imaging of relatively strong objects in partially coherent illumination, the coherence properties of thermionic emission sources and the detection of objects in quantum noise limited images are considered. IMAGIC, a fast, flexible and friendly image analysis software package is described. Intelligent averaging of molecular images is discussed. (C.F.)

  11. Spatiotemporal matrix image formation for programmable ultrasound scanners

    Science.gov (United States)

    Berthon, Beatrice; Morichau-Beauchant, Pierre; Porée, Jonathan; Garofalakis, Anikitos; Tavitian, Bertrand; Tanter, Mickael; Provost, Jean

    2018-02-01

    As programmable ultrasound scanners become more common in research laboratories, it is increasingly important to develop robust software-based image formation algorithms that can be obtained in a straightforward fashion for different types of probes and sequences with a small risk of error during implementation. In this work, we argue that as the computational power keeps increasing, it is becoming practical to directly implement an approximation to the matrix operator linking reflector point targets to the corresponding radiofrequency signals via thoroughly validated and widely available simulations software. Once such a spatiotemporal forward-problem matrix is constructed, standard and thus highly optimized inversion procedures can be leveraged to achieve very high quality images in real time. Specifically, we show that spatiotemporal matrix image formation produces images of similar or enhanced quality when compared against standard delay-and-sum approaches in phantoms and in vivo, and show that this approach can be used to form images even when using non-conventional probe designs for which adapted image formation algorithms are not readily available.

  12. Linear micromechanical stepping drive for pinhole array positioning

    International Nuclear Information System (INIS)

    Endrödy, Csaba; Mehner, Hannes; Hoffmann, Martin; Grewe, Adrian

    2015-01-01

    A compact linear micromechanical stepping drive for positioning a 7 × 5.5 mm 2 optical pinhole array is presented. The system features a step size of 13.2 µm and a full displacement range of 200 µm. The electrostatic inch-worm stepping mechanism shows a compact design capable of positioning a payload 50% of its own weight. The stepping drive movement, step sizes and position accuracy are characterized. The actuated pinhole array is integrated in a confocal chromatic hyperspectral imaging system, where coverage of the object plane, and therefore the useful picture data, can be multiplied by 14 in contrast to a non-actuated array. (paper)

  13. Oxidative Attack of Carbon/Carbon Substrates through Coating Pinholes

    Science.gov (United States)

    Jacobson, Nathan S.; Leonhardt, Todd; Curry, Donald; Rapp, Robert A.

    1998-01-01

    A critical issue with oxidation protected carbon/carbon composites used for spacecraft thermal protection is the formation of coating pinholes. In laboratory experiments, artificial pinholes were drilled through SiC-coatings on a carbon/carbon material and the material was oxidized at 600, 1000, and 1400 C at reduced pressures of air. The attack of the carbon/carbon was quantified by both weight loss and a novel cross-sectioning technique. A two-zone, one dimensional diffusion control model was adapted to analyze this problem. Agreement of the model with experiment was reasonable at 1000 and 1400 C; however results at lower temperatures show clear deviations from the theory suggesting that surface reaction control plays a role.

  14. A new reconstruction strategy for image improvement in pinhole SPECT

    International Nuclear Information System (INIS)

    Zeniya, Tsutomu; Watabe, Hiroshi; Kim, Kyeong Min; Teramoto, Noboru; Hayashi, Takuya; Iida, Hidehiro; Aoi, Toshiyuki; Sohlberg, Antti; Kudo, Hiroyuki

    2004-01-01

    Pinhole single-photon emission computed tomography (SPECT) is able to provide information on the biodistribution of several radioligands in small laboratory animals, but has limitations associated with non-uniform spatial resolution or axial blurring. We have hypothesised that this blurring is due to incompleteness of the projection data acquired by a single circular pinhole orbit, and have evaluated a new strategy for accurate image reconstruction with better spatial resolution uniformity. A pinhole SPECT system using two circular orbits and a dedicated three-dimensional ordered subsets expectation maximisation (3D-OSEM) reconstruction method were developed. In this system, not the camera but the object rotates, and the two orbits are at 90 and 45 relative to the object's axis. This system satisfies Tuy's condition, and is thus able to provide complete data for 3D pinhole SPECT reconstruction within the whole field of view (FOV). To evaluate this system, a series of experiments was carried out using a multiple-disk phantom filled with 99m Tc solution. The feasibility of the proposed method for small animal imaging was tested with a mouse bone study using 99m Tc-hydroxymethylene diphosphonate. Feldkamp's filtered back-projection (FBP) method and the 3D-OSEM method were applied to these data sets, and the visual and statistical properties were examined. Axial blurring, which was still visible at the edge of the FOV even after applying the conventional 3D-OSEM instead of FBP for single-orbit data, was not visible after application of 3D-OSEM using two-orbit data. 3D-OSEM using two-orbit data dramatically reduced the resolution non-uniformity and statistical noise, and also demonstrated considerably better image quality in the mouse scan. This system may be of use in quantitative assessment of bio-physiological functions in small animals. (orig.)

  15. Use of Gamma Correction Pinhole Bone Scans in Trauma

    International Nuclear Information System (INIS)

    Bahk, Youg Whee; Chung, Youg An; Park, Jung Mee

    2012-01-01

    99 mTc hydroxydiphosphonate (HDP) bone scanning is a classic metabolic nuclear imaging method and the most frequently performed examination. Clinically, it has long been cherished as an indispensable diagnostic screening tool and for monitoring of patients with bone, joint, and soft tissue diseases. The HDP bone scan, the pinhole scan in particular, is known for its ability to detect increased, decreased, or defective tracer uptake along with magnified anatomy. Unfortunately, however, the findings of such uptake changes are not specific in many traumatic bone disorders, especially when lesions are minute and complex. This study discusses the recently introduced gamma correction pinhole bone scan (GCPBS), emphasizing its usefulness in the diagnosis of traumatic bone diseases including occult fractures; and fish vertebra. Indeed, GCPBS can remarkably enhance the diagnostic feasibility of HDP pinhole bone scans by refining the topography, pathologic anatomy, and altered chemical profile of the traumatic diseases in question. The fine and precise depiction of anatomic and metabolic changes in these diseases has been shown to be unique to GCPBS, and they are not appreciated on conventional radiographs, multiple detector CT, or ultrasonographs. It is true that MR imaging can portray proton change, but understandably, it is a manifestation that is common to any bone disease

  16. Investigation of the hard x-ray background in backlit pinhole imagers

    Energy Technology Data Exchange (ETDEWEB)

    Fein, J. R., E-mail: jrfein@umich.edu; Holloway, J. P. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, Michigan 48109-2143 (United States); Peebles, J. L. [Center for Energy Research, University of California, San Diego, La Jolla, California 92093 (United States); Keiter, P. A.; Klein, S. R.; Kuranz, C. C.; Manuel, M. J.-E.; Drake, R. P. [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109-2143 (United States)

    2014-11-15

    Hard x-rays from laser-produced hot electrons (>10 keV) in backlit pinhole imagers can give rise to a background signal that decreases signal dynamic range in radiographs. Consequently, significant uncertainties are introduced to the measured optical depth of imaged plasmas. Past experiments have demonstrated that hard x-rays are produced when hot electrons interact with the high-Z pinhole substrate used to collimate the softer He-α x-ray source. Results are presented from recent experiments performed on the OMEGA-60 laser to further study the production of hard x-rays in the pinhole substrate and how these x-rays contribute to the background signal in radiographs. Radiographic image plates measured hard x-rays from pinhole imagers with Mo, Sn, and Ta pinhole substrates. The variation in background signal between pinhole substrates provides evidence that much of this background comes from x-rays produced in the pinhole substrate itself. A Monte Carlo electron transport code was used to model x-ray production from hot electrons interacting in the pinhole substrate, as well as to model measurements of x-rays from the irradiated side of the targets, recorded by a bremsstrahlung x-ray spectrometer. Inconsistencies in inferred hot electron distributions between the different pinhole substrate materials demonstrate that additional sources of hot electrons beyond those modeled may produce hard x-rays in the pinhole substrate.

  17. Reconstruction of quasimonochromatic images for multispectral x-ray imaging with a pinhole array and a flat Bragg mirror

    International Nuclear Information System (INIS)

    Izumi, N.; Barbee, T. W.; Koch, J. A.; Mancini, R. C.; Welser, L. A.

    2006-01-01

    We have developed a software package for reconstruction of quasimonochromatic images from a multiple monochromatic x-ray imager for inertial confinement fusion implosions. The instrument consists of a pinhole array, a multilayer Bragg mirror, and an image detector. The pinhole array projects hundreds of images onto the detector after reflection off the multilayer Bragg mirror, which introduces spectral dispersion along the reflection axis. The quasimonochromatic images of line emissions and continuum emissions can be used for measurement of temperature and density maps of implosion plasmas. In this article, we describe a computer-aided processing technique for systematic reconstruction of quasimonochromatic images from raw data. This technique provides flexible spectral bandwidth selection and allows systematic subtraction of continuum emission from line emission images

  18. A study of the decoding of multiple pinhole coded aperture RI tomographic images

    International Nuclear Information System (INIS)

    Hasegawa, Takeo; Kobayashi, Akitoshi; Nishiyama, Yutaka; Akagi, Kiyoshi; Uehata, Hiroshi

    1981-01-01

    In order to obtain a radioisotope (RI) tomographic image, there are various, methods, including the RCT method, Time Modulate method, and Multiple Pinhole Coded Aperture (MPCA) method and others. The MPCA method has several advantages. Using the MPCA method, there is no need to move either the detector or the patient, Furthermore, the generally used γ-camera may be used without any alterations. Due to certain problems in reconstructing the tomographic image, the use of the MPCA method in clinical practice is limited to representation of small organs (e.g. heart) using the 7-Pinhole collimator. This research presents an experimental approach to overcome the problems in reconstruction of tomographic images of large organs (organs other than the heart, such as the brain, liver, lung etc.) by introducing a reconstruction algorithm and correction software into the MPCA method. There are 2 main problems in MPCA image reconstruction: (1) Due to the rounding-off procedure, there is both point omission and shifting of point coordinates. (2) The central portion is characterized by high-counts. Both of these problems were solved by incorporating a reconstruction algorithm and a correction function. The resultant corrected tomographic image was processed using a filter derived from subjecting a PSF to a Fourier transform. Thus, it has become possible to obtain a high-quality tomographic image of large organs for clinical use. (author)

  19. Pinhole bone scan mapping of metabolic profiles in osteoarthritis of the knee: a radiographic correlation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S. H.; Kim, H. H.; Chung, Y. A.; Chung, S. K.; Bahk, Y. W. [College of Medicine, The Catholic Univ. of Korea, Seoul (Korea, Republic of)

    1999-07-01

    Osteoarthritis (OA) is mixture of damage to a joint and reaction induced therefrom. Heterogeneity, slow change and no proper means of assessing pathology make it a difficult disease to study. Diagnosis can be made by radiography when OA is established. But subtle metabolic change without radiographic alteration can only be detected by bone scan. Present study was performed to assess metabolic profiles of OA of the knee with various radiographic and preradiographic changes using pinhole bone scan (PBS). PBS and radiography were taken at the same time or a few days apart. We used single-head gamma camera and a 4-mm pinhole collimator. Patients were 9 men and 19 women (30-74 yr with mean being 55). PBS was correlated with radiography in each case. Increased tracer uptake was seen in 111 lesions in 28 knees. Intensity was arbitrarily graded into Grade 0-2. The results were divided into group with radiographic change (n=85; Table) and group without (n=26). Generally, tracer uptake was much intense in the sclerotic and cystic form. In radiographically normal group pathological uptake occurred mostly in subchondral bone (n=17) and some in the femoral condyle (n=9) denoting that subchondral bone is the most vulnerable. PBS is sensitive indicator of metabolic alternations in various disease processes of OA in both radiographically normal and abnormal cases.

  20. How risky are pinholes in gloves? A rational appeal for the integrity of gloves for isolators.

    Science.gov (United States)

    Gessler, Angela; Stärk, Alexandra; Sigwarth, Volker; Moirandat, Claude

    2011-01-01

    Isolators provide a high degree of protection for the product and/or the environment and operators in pharmaceutical production, as well as for analytical and sterility testing. Gloves allow for performing testing and for easy access to the process. Due to their nature-thin plastic, highly flexible-and their risk of puncture or rupture, they are regarded as one of the main potential sources of contamination. Glove integrity testing is therefore a main issue and has been addressed by many regulations such as those imposed by the USP, U.S. Food and Drug Administration, and Pharmaceutical Inspection Convention. This paper presents a short overview of different glove integrity test procedures and their ability to detect leaking gloves. Additionally, extensive microbiological tests have been performed to give more evidence and cross-correlation to physical testing. Most of the physical tests have limitations either in detecting pinholes and/or they are difficult to implement for routine testing. Microbiological tests are only applicable for evaluation and validation purposes, but not for routine testing, because they are time-consuming and do not allow immediate action. Routine visual verification of gloves by trained personnel turns out to be a very reliable technique. Additional microbiological tests supported by microbiological environmental monitoring helped to develop a new concept presented here on how to handle gloves with pinholes. It is proposed not to automatically consider a pinhole in a glove as a breach in isolator integrity, but to consider any action in view of controlling and monitoring the effective bioload on the outside of the gloves. With the combination of semi-automatic physical testing with independent protocol, visual inspection, and control of bioload through microbiological environmental monitoring potential contamination, risks can be minimized and maximum safety maintained. Isolators are enclosure designs to protect critical handling and

  1. High-Damage-Threshold Pinhole for Glass Fusion Laser Applications

    International Nuclear Information System (INIS)

    Kumit, N.A.; Letzring, S.A.; Johnson, R.P.

    1998-01-01

    We are investigating methods to fabricate high-damage-threshold spatial-filter pinholes that might not be susceptible to plasma closure for relatively high energies and long pulses. These are based on the observation that grazing-incidence reflection from glass can withstand in excess of 5 kJ/cm 2 (normal to the beam) without plasma formation. The high damage threshold results from both the cos q spreading of the energy across the surface and the reflection of a large fraction of the energy from the surface, thereby greatly reducing the field strength within the medium

  2. Morphobiochemical diagnosis of acute trabecular microfractures using gamma correction Tc-99m HDP pinhole bone scan with histopathological verification.

    Science.gov (United States)

    Bahk, Yong-Whee; Hwang, Seok-Ha; Lee, U-Young; Chung, Yong-An; Jung, Joo-Young; Jeong, Hyeonseok S

    2017-11-01

    We prospectively performed gamma correction pinhole bone scan (GCPBS) and histopathologic verification study to make simultaneous morphobiochemical diagnosis of trabecular microfractures (TMF) occurred in the femoral head as a part of femoral neck fracture.Materials consisted of surgical specimens of the femoral head in 6 consecutive patients. The specimens were imaged using Tc-99m hydroxymethylene diphosphonate (HDP) pinhole scan and processed by the gamma correction. After cleansing with 10% formalin solution, injured specimen surface was observed using a surgical microscope to record TMF. Morphological findings shown in the photograph, naive pinhole bone scan, GCPBS, and hematoxylin-eosin (H&E) stain of the specimen were reciprocally correlated for histological verification and the usefulness of suppression and enhancement of Tc-99m HDP uptake was biochemically investigated in TMF and edema and hemorrhage using gamma correction.On the one hand, GCPBS was able to depict the calcifying calluses in TMF with enhanced Tc-99m HDP uptake. They were pinpointed, speckled, round, ovoid, rod-like, geographic, and crushed in shape. The smallest callus measured was 0.23 mm in this series. On the other hand, GCPBS biochemically was able to discern the calluses with enhanced high Tc-99m HDP uptake from the normal and edema dipped and hemorrhage irritated trabeculae with washed out uptake.Morphobiochemically, GCPBS can clearly depict microfractures in the femoral head produced by femoral neck fracture. It discerns the microcalluses with enhanced Tc-99m HDP uptake from the intact and edema dipped and hemorrhage irritated trabeculae with suppressed washed out Tc-99m HDP uptake. Both conventional pinhole bone scan and gamma correction are useful imaging means to specifically diagnose the microcalluses naturally formed in TMF.

  3. An accurate and efficient system model of iterative image reconstruction in high-resolution pinhole SPECT for small animal research

    Energy Technology Data Exchange (ETDEWEB)

    Huang, P-C; Hsu, C-H [Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan (China); Hsiao, I-T [Department Medical Imaging and Radiological Sciences, Chang Gung University, Tao-Yuan, Taiwan (China); Lin, K M [Medical Engineering Research Division, National Health Research Institutes, Zhunan Town, Miaoli County, Taiwan (China)], E-mail: cghsu@mx.nthu.edu.tw

    2009-06-15

    Accurate modeling of the photon acquisition process in pinhole SPECT is essential for optimizing resolution. In this work, the authors develop an accurate system model in which pinhole finite aperture and depth-dependent geometric sensitivity are explicitly included. To achieve high-resolution pinhole SPECT, the voxel size is usually set in the range of sub-millimeter so that the total number of image voxels increase accordingly. It is inevitably that a system matrix that models a variety of favorable physical factors will become extremely sophisticated. An efficient implementation for such an accurate system model is proposed in this research. We first use the geometric symmetries to reduce redundant entries in the matrix. Due to the sparseness of the matrix, only non-zero terms are stored. A novel center-to-radius recording rule is also developed to effectively describe the relation between a voxel and its related detectors at every projection angle. The proposed system matrix is also suitable for multi-threaded computing. Finally, the accuracy and effectiveness of the proposed system model is evaluated in a workstation equipped with two Quad-Core Intel X eon processors.

  4. Image reconstruction methods for the PBX-M pinhole camera

    International Nuclear Information System (INIS)

    Holland, A.; Powell, E.T.; Fonck, R.J.

    1990-03-01

    This paper describes two methods which have been used to reconstruct the soft x-ray emission profile of the PBX-M tokamak from the projected images recorded by the PBX-M pinhole camera. Both methods must accurately represent the shape of the reconstructed profile while also providing a degree of immunity to noise in the data. The first method is a simple least squares fit to the data. This has the advantage of being fast and small, and thus easily implemented on the PDP-11 computer used to control the video digitizer for the pinhole camera. The second method involves the application of a maximum entropy algorithm to an overdetermined system. This has the advantage of allowing the use of a default profile. This profile contains additional knowledge about the plasma shape which can be obtained from equilibrium fits to the external magnetic measurements. Additionally the reconstruction is guaranteed positive, and the fit to the data can be relaxed by specifying both the amount and distribution of noise in the image. The algorithm described has the advantage of being considerably faster, for an overdetermined system, than the usual Lagrange multiplier approach to finding the maximum entropy solution. 13 refs., 24 figs

  5. A study of image formation in lenses by visual materials

    International Nuclear Information System (INIS)

    Bozkurt, E.

    2005-01-01

    The aim of this study is to devise guide materials for teachers in order for the physics subjects in high school curriculum to be taligbt more efficiently. it was researched how effective a teaching program, enriched with experimental and display methods prepared for this purpose Bloom can be on, the success of the 11 th class students with the help of a data show prepared in Power Point while they are studying the subject 'Lenses and Image Formation in Lenses' in unit on Light. While preparing the materials, we detected some misconceptions in various available course books published to be used in schools. It is hoped that the materials prepared in this study would contribute to the elimination of such misconceptions

  6. Pinhole SPECT: high resolution imaging of brain tumours in small laboratory animals

    International Nuclear Information System (INIS)

    Franceschim, M.; Bokulic, T.; Kusic, Z.; Strand, S.E.; Erlandsson, K.

    1994-01-01

    The performance properties of pinhole SPECT and the application of this technology to evaluate radionuclide uptake in brain in small laboratory animals were investigated. System sensitivity and spatial resolution measurements of a rotating scintillation camera system were made for a low energy pinhole collimator equipped with 2.0 mm aperture pinhole insert. Projection data were acquired at 4 degree increments over 360 degrees in the step and shoot mode using a 4.5 cm radius of rotation. Pinhole planar and SPECT imaging were obtained to evaluate regional uptake of Tl-201, Tc-99m-MIBI, Tc-99m-HMPAO and Tc-99m-DTPA in tumor and control regions of the brain in a primary brain tumor model in Fisher 344 rats. Pinhole SPECT images were reconstructed using a modified cone- beam algorithm developed from a two dimensional fan-beam filtered backprojection algorithm. The reconstructed transaxial resolution of 2.8 FWHM and system sensitivity of 0.086 c/s/kBq with the 2.0 mm pinhole collimator aperture were measured. Tumor to non-tumor uptake ratios at 19-28 days post tumor cell inoculation varied by a factor > 20:1 on SPECT images. Pinhole SPECT provides an important new approach for performing high resolution imaging: the resolution properties of pinhole SPECT are superior to those which have been achieved with conventional SPECT or PET imaging technologies. (author)

  7. Feasibility study on X-ray source with pinhole imaging method

    International Nuclear Information System (INIS)

    Qiu Rui; Li Junli

    2007-01-01

    In order to verify the feasibility of study on X-ray source with pinhole imaging method, and optimize the design of X-ray pinhole imaging system, an X-ray pinhole imaging equipment was set up. The change of image due to the change of the position and intensity of X-ray source was estimated with mathematical method and validated with experiment. The results show that the change of the spot position and gray of the spot is linearly related with the change of the position and intensity of X-ray source, so it is feasible to study X-ray source with pinhole imaging method in this application. The results provide some references for the design of X-ray pinhole imaging system. (authors)

  8. Emulation and design of terahertz reflection-mode confocal scanning microscopy based on virtual pinhole

    Science.gov (United States)

    Yang, Yong-fa; Li, Qi

    2014-12-01

    In the practical application of terahertz reflection-mode confocal scanning microscopy, the size of detector pinhole is an important factor that determines the performance of spatial resolution characteristic of the microscopic system. However, the use of physical pinhole brings some inconvenience to the experiment and the adjustment error has a great influence on the experiment result. Through reasonably selecting the parameter of matrix detector virtual pinhole (VPH), it can efficiently approximate the physical pinhole. By using this approach, the difficulty of experimental calibration is reduced significantly. In this article, an imaging scheme of terahertz reflection-mode confocal scanning microscopy that is based on the matrix detector VPH is put forward. The influence of detector pinhole size on the axial resolution of confocal scanning microscopy is emulated and analyzed. Then, the parameter of VPH is emulated when the best axial imaging performance is reached.

  9. The usefulness of postoperative pinhole bone scintigraphy in the assessment of prognosis after multiple drilling or vascularized bone graft in patients with avascular necrosis of femoral head

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Young An; Kim, Sung Hoon; Cheon, Kyung Ah; Park, Young Ha; Jeong, Soo Kyo [College of Medicine, The Catholic Univ., Seoul (Korea, Republic of); Song Moon Kab [Eulji Medical Center, Taejon (Korea, Republic of)

    1999-08-01

    It is important to evaluate the healing process of avascular necrosis (AVN) involving femoral head after treatment. The purpose of this study was to assess the usefulness of pinhole bone scintigraphy in the AVN of femoral head after surgery. We analyzed the changing pattern of pinhole bone scintigram in 21 femoral heads of 16 patients (14 lesions/11 male, 7 lesions/5 female, mean age : 39.4 yrs) before and after multiple drilling or vascularized bone grafting for AVN of the femoral head. In all patients, pre-operative scintigrams were obtained at 1 to 3 months before treatment and the first post-operative scintigrams were obtained at 1 to 3 months after treatment. All patients were followed for 2 to 4 years after operation. The findings of the pinhole scintigrams were divided into three patterns: 1) curvilinear, 2) scattered spotty and 3) underdetermined. The 10 of 11 lesions with curvilinear pattern had good postoperative clinical and radiological follow-up findings. However, all 6 lesions with scattered spotty pattern showed poor postoperative findings, which necessitated total hip joint replacement. Of the 4 lesions with undetermined pattern, 2 required total hip joint replacement. There was significant difference in postoperative prognosis between the curvilinear and scattered spotty patterns (p<0.05). We conclude that the pattern of pinhole bone scintigram obtained within 1 to 3 months after multiple drilling or vascularized bone graft operation is a useful prognostic indicator in the AVN of femoral head.

  10. The usefulness of postoperative pinhole bone scintigraphy in the assessment of prognosis after multiple drilling or vascularized bone graft in patients with avascular necrosis of femoral head

    International Nuclear Information System (INIS)

    Jeong, Young An; Kim, Sung Hoon; Cheon, Kyung Ah; Park, Young Ha; Jeong, Soo Kyo; Song Moon Kab

    1999-01-01

    It is important to evaluate the healing process of avascular necrosis (AVN) involving femoral head after treatment. The purpose of this study was to assess the usefulness of pinhole bone scintigraphy in the AVN of femoral head after surgery. We analyzed the changing pattern of pinhole bone scintigram in 21 femoral heads of 16 patients (14 lesions/11 male, 7 lesions/5 female, mean age : 39.4 yrs) before and after multiple drilling or vascularized bone grafting for AVN of the femoral head. In all patients, pre-operative scintigrams were obtained at 1 to 3 months before treatment and the first post-operative scintigrams were obtained at 1 to 3 months after treatment. All patients were followed for 2 to 4 years after operation. The findings of the pinhole scintigrams were divided into three patterns: 1) curvilinear, 2) scattered spotty and 3) underdetermined. The 10 of 11 lesions with curvilinear pattern had good postoperative clinical and radiological follow-up findings. However, all 6 lesions with scattered spotty pattern showed poor postoperative findings, which necessitated total hip joint replacement. Of the 4 lesions with undetermined pattern, 2 required total hip joint replacement. There was significant difference in postoperative prognosis between the curvilinear and scattered spotty patterns (p<0.05). We conclude that the pattern of pinhole bone scintigram obtained within 1 to 3 months after multiple drilling or vascularized bone graft operation is a useful prognostic indicator in the AVN of femoral head

  11. Possible application of nonredundant pinhole arrays to fuel pin imaging

    International Nuclear Information System (INIS)

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

    1975-11-01

    LMFBR Safety Test Facility imaging experiments rely on emission of radiation by the fuel pins and thus appear to strongly complement radiographic techniques in that they are most employable during peak excursion--a time of least favorable radiographic signal--to--noise ratio. Radiography, on the other hand, can provide information long before or after the excursion--times of below threshold signal for direct imaging techniques. An underlying premise of any imaging experiment is that, in addition to sufficient brightness, sufficient contrast exists in the scene. A further restriction is imposed by intervening materials, such as the wall of a containment vessel, that not only absorb but also scatter the radiation. These questions are approached by examining the properties of potential recording instrumentation, of pinhole apertures, and of the necessary radiation sources

  12. Fresnel's phase observation by means of the pinhole Young's experiment

    International Nuclear Information System (INIS)

    Medina, F.F.; Matteucci, G.

    2000-04-01

    Using the conventional Young's experiment with two pinholes, we observe the shift effect of the Fresnel's phase on the interference patterns, by measuring its intensity on the optical axis. It allows us to propose a criterion for distinguishing between Fraunhofer and Fresnel diffraction. Indeed, in the Fraunhofer domain the Young's patterns will be centered on the optical axis. As a consequence, only constructive interference will occur at this point. But in the Fresnel domain, the Young's patterns will be laterally shifted in such a way that constructive and destructive interference will occur alternatively on the optical axis, and the intensity of the diffraction pattern at this point will oscillate. Extended diffracting apertures can be analyzed as ensembles of Young's pairs of wavelet sources. From this point of view, the intensity distribution they produce on the detector plane results from the superposition of all their interference patterns. (author)

  13. Experimental investigation on the influence of instrument settings on pixel size and nonlinearity in SEM image formation

    DEFF Research Database (Denmark)

    Carli, Lorenzo; Genta, Gianfranco; Cantatore, Angela

    2010-01-01

    The work deals with an experimental investigation on the influence of three Scanning Electron Microscope (SEM) instrument settings, accelerating voltage, spot size and magnification, on the image formation process. Pixel size and nonlinearity were chosen as output parameters related to image...... quality and resolution. A silicon grating calibrated artifact was employed to investigate qualitatively and quantitatively, through a designed experiment approach, the parameters relevance. SEM magnification was found to account by far for the largest contribution on both parameters under consideration...

  14. Pinhole imaging in Legg--Perthes disease: further observations

    International Nuclear Information System (INIS)

    Danigelis, J.A.

    1976-01-01

    Fifty-nine patients with Legg--Perthes disease and 12 others were studied using /sup 99m/Tc-polyphosphate and the pinhole collimator imaging technique. Radiographs of both hips were correlated with images in each patient. In the Legg--Perthes patients, a radionuclide uptake deficiency of variable size was observed in the proximal femoral epiphysis (EOC), which we believe is related to varying degrees of impaired blood supply. During later disease stages, adjacent zones of increased radio-nuclide activity or revascularization were observed that would replace the uptake defect eventually. Unless radiographic evidence of new bone formation was observed in the EOC, it was impossible to predict either the presence or extent of revascularization until bone imaging was done. Those patients with revascularization activity in the EOC exhibited a relatively short time interval (average, 3.2 months) before evidence of new bone formation radiographically. Others with increased radionuclide concentration limited to the growth plate and/or metaphysis averaged a much longer 7.8 months. In two patients there was a reversal of the initially increased activity in the growth plate, suggesting another vascular insult. There were no false-negative bone-image findings in the 12 cases that clinically and/or radiologically simulated Legg-Perthes disease. Our image studies correlate well with published histopathologic investigations, indicating to us that assessment of extent of pathologic involvement and of the disease course is facilitated by this technique. Subsequently, this could influence treatment selection and provide a more objective baseline from which to judge treatment results. Continued experience suggests pinhole bone imaging has useful clinical application in Legg--Perthes disease and other childhood hip disorders

  15. Pinhole imaging in Legg-Perthes disease: further observations.

    Science.gov (United States)

    Danigelis, J A

    1976-01-01

    Fifty-nine patients with Legg-Perthes disease and 12 others were studied using 99mTc-polyphosphate and the pinhole collimator imaging technique. Radiographs of both hips were correlated with images in each patient. In the Legg-Perthes patients, a radionuclide uptake deficiency of variable size was observed in the proximal femoral epiphysis (EOC), which we believe is related to varying degrees of impaired blood supply. During later disease stages, adjacent zones of increased radionuclide activity of revascularization were observed that would replace the uptake defect eventually. Unless radiographic evidence of new bone formation was observed in the EOC, it was impossible to predict either the presence or extent of revascularization until bone imaging was done. Those patients with revascularization activity in the EOC exhibited a relatively short time interval (average, 3.2 months) before evidence of new bone formation radiographically. Others with increased radionuclide concentration limited to the growth plate and/or metaphysis averaged a much longer 7.8 months. In two patients there was a reversal of the initially increased activity in the growth plate, suggesting another vascular insult. There were no false-negative bone-image findings in the 12 cases that clinically and/or radiologically simulated Legg-Perthes disease. Our image studies correlate well with published histopathologic investigations, indicating to us that assessment of extent of pathologic involvement and of the disease course is facilitated by this technique. Subsequently, this could influence treatment selection and provide a more objective baseline from which to judge treatment results. Continued experience suggests pinhole bone imaging has useful clinical application in Legg-Perthes disease and other childhood hip disorders.

  16. Transmission electron microscopy physics of image formation and microanalysis

    CERN Document Server

    Reimer, Ludwig

    1984-01-01

    The aim of this book is to outline the physics of image formation, electron­ specimen interactions and image interpretation in transmission electron mic­ roscopy. The book evolved from lectures delivered at the University of Munster and is a revised version of the first part of my earlier book Elek­ tronenmikroskopische Untersuchungs- und Priiparationsmethoden, omitting the part which describes specimen-preparation methods. In the introductory chapter, the different types of electron microscope are compared, the various electron-specimen interactions and their applications are summarized and the most important aspects of high-resolution, analytical and high-voltage electron microscopy are discussed. The optics of electron lenses is discussed in Chapter 2 in order to bring out electron-lens properties that are important for an understanding of the function of an electron microscope. In Chapter 3, the wave optics of elec­ trons and the phase shifts by electrostatic and magnetic fields are introduced; Fresne...

  17. Scanning electron microscopy physics of image formation and microanalysis

    CERN Document Server

    Reimer, Ludwig

    1985-01-01

    The aim of this book is to outline the physics of image formation, electron­ specimen interactions, imaging modes, the interpretation of micrographs and the use of quantitative modes "in scanning electron microscopy (SEM). lt forms a counterpart to Transmission Electron Microscopy (Vol. 36 of this Springer Series in Optical Sciences) . The book evolved from lectures delivered at the University of Münster and from a German text entitled Raster-Elektronenmikroskopie (Springer-Verlag), published in collaboration with my colleague Gerhard Pfefferkorn. In the introductory chapter, the principles of the SEM and of electron­ specimen interactions are described, the most important imaging modes and their associated contrast are summarized, and general aspects of eiemental analysis by x-ray and Auger electron emission are discussed. The electron gun and electron optics are discussed in Chap. 2 in order to show how an electron probe of small diameter can be formed, how the elec­ tron beam can be blanked at high fre...

  18. A new X-ray pinhole camera for energy dispersive X-ray fluorescence imaging with high-energy and high-spatial resolution

    Energy Technology Data Exchange (ETDEWEB)

    Romano, F.P., E-mail: romanop@lns.infn.it [IBAM, CNR, Via Biblioteca 4, 95124 Catania (Italy); INFN-LNS, Via S. Sofia 62, 95123 Catania (Italy); Altana, C. [INFN-LNS, Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania (Italy); Cosentino, L.; Celona, L.; Gammino, S.; Mascali, D. [INFN-LNS, Via S. Sofia 62, 95123 Catania (Italy); Pappalardo, L. [IBAM, CNR, Via Biblioteca 4, 95124 Catania (Italy); INFN-LNS, Via S. Sofia 62, 95123 Catania (Italy); Rizzo, F. [INFN-LNS, Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania (Italy)

    2013-08-01

    A new X-ray pinhole camera for the Energy Dispersive X-ray Fluorescence (ED-XRF) imaging of materials with high-energy and high-spatial resolution, was designed and developed. It consists of a back-illuminated and deep depleted CCD detector (composed of 1024 × 1024 pixels with a lateral size of 13 μm) coupled to a 70 μm laser-drilled pinhole-collimator, positioned between the sample under analysis and the CCD. The X-ray pinhole camera works in a coaxial geometry allowing a wide range of magnification values. The characteristic X-ray fluorescence is induced on the samples by irradiation with an external X-ray tube working at a maximum power of 100 W (50 kV and 2 mA operating conditions). The spectroscopic capabilities of the X-ray pinhole camera were accurately investigated. Energy response and energy calibration of the CCD detector were determined by irradiating pure target-materials emitting characteristic X-rays in the energy working-domain of the system (between 3 keV and 30 keV). Measurements were performed by using a multi-frame acquisition in single-photon counting. The characteristic X-ray spectra were obtained by an automated processing of the acquired images. The energy resolution measured at the Fe–Kα line is 157 eV. The use of the X-ray pinhole camera for the 2D resolved elemental analysis was investigated by using reference-patterns of different materials and geometries. The possibility of the elemental mapping of samples up to an area of 3 × 3 cm{sup 2} was demonstrated. Finally, the spatial resolution of the pinhole camera was measured by analyzing the profile function of a sharp-edge. The spatial resolution determined at the magnification values of 3.2 × and 0.8 × (used as testing values) is about 90 μm and 190 μm respectively. - Highlights: • We developed an X-ray pinhole camera for the 2D X-ray fluorescence imaging. • X-ray spectra are obtained by a multi-frame acquisition in single photon mode. • The energy resolution in the X

  19. Imaging of fast-neutron sources using solid-state track-recorder pinhole radiography

    International Nuclear Information System (INIS)

    Ruddy, F.H.; Gold, R.; Roberts, J.H.; Kaiser, B.J.; Preston, C.C.

    1983-08-01

    Pinhole imaging methods are being developed and tested for potential future use in imaging the intense neutron source of the Fusion Materials Irradiation Test (FMIT) Facility. Previously reported, extensive calibration measurements of the proton, neutron, and alpha particle response characteristics of CR-39 polymer solid state track recorders (SSTRs) are being used to interpret the results of imaging experiments using both charged particle and neutron pinhole collimators. High resolution, neutron pinhole images of a 252 Cf source have been obtained in the form of neutron induced proton recoil tracks in CR-39 polymer SSTR. These imaging experiments are described as well as their potential future applications to FMIT

  20. A study of the decoding of multiple pinhole coded aperture RI tomographic images

    International Nuclear Information System (INIS)

    Hasegawa, Takeo; Kobayashi, Akitoshi; Nishiyama, Yutaka

    1980-01-01

    The authors constructed a Multiple Pinhole Coded Aperture (MPCA) and developed related decoding software. When simple coordinate transformation was performed, omission of points and shifting of counts occurred. By selecting various tomographic planes and collecting count for each tomographic depth from the shadowgram, a solution to these problems was found. The counts from the central portion of the tomographic image from the MPCA were incorrectly high, this was rectified by a correction function to improve the uniformity correction program of the γ-camera. Depth resolution of the tomographic image improved in proportion to the area encompassed by the pinhole configuration. An MPCA with a uniform arrangement of pinholes (e, g, pinholes in an arrangement parallel to the X-axis or the Y-axis) yielded decoded tomographic images of inferior quality. Optimum results were obtained with a ring-shaped arrangement yielding clinically applicable tomographic images even for large objects. (author)

  1. Time resolved x-ray pinhole photography of compressed laser fusion targets

    International Nuclear Information System (INIS)

    Attwood, D.T.

    1976-01-01

    Use of the Livermore x-ray streak camera to temporally record x-ray pinhole images of laser compressed targets is described. Use is made of specially fabricated composite x-ray pinholes which are near diffraction limited for 6 A x-rays, but easily aligned with a He--Ne laser of 6328 A wavelength. With a 6 μm x-ray pinhole, the overall system can be aligned to 5 μm accuracy and provides implosion characteristics with space--time resolutions of approximately 6 μm and 15 psec. Acceptable criteria for pinhole alignment, requisite x-ray flux, and filter characteristics are discussed. Implosion characteristics are presented from our present experiments with 68 μm diameter glass microshell targets and 0.45 terawatt, 70 psec Nd laser pulses. Final implosion velocities in excess of 3 x 10 7 cm/sec are evident

  2. Pinhole Breaches in Spent Fuel Containers: Improvements to Conservative Models of Aerosol Release and Plugging

    International Nuclear Information System (INIS)

    Casella, Andrew M.; Loyalka, Sudarsham K.; Hanson, Brady D.

    2007-01-01

    By taking the differential forms of transport and equations of state, the equations describing aerosol transport in pinhole breaches can be solved directly using continuous models. The results are compared with discrete models.

  3. Plugging Effects on Depressurization Time in Dry Storage Containers with Pinhole Breaches

    International Nuclear Information System (INIS)

    Casella, Andrew M.; LOYALKA, SUDARSHAN K.; Hanson, Brady D.

    2006-01-01

    As continuation on previous work, we now examine the effect that aerosol deposition may have on plugging pinhole breaches in spent fuel containers. A model is developed considering only diffusive settling

  4. Studies of closure phenomena in pinholes irradiated by Nd laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Auerbach, J.M.; Holmes, N.C.; Hunt, J.T.; Linford, G.J.

    1978-08-21

    The plasma closure of spatial filter pinholes is a critical parameter in the performance of high energy glass laser systems. Using 50 to 100 J, 300 psec FWHM laser pulses on the Janus laser, an investigation has been made on closure effects in 300 ..mu..m to 500 ..mu..m diameter pinholes of various materials and thicknesses. Calorimetry measurements have yielded data on pinhole transmission and intensity loading on the periphery of the pinhole. Ultrafast streak photography measurements indicate effective closure velocities of 2 x 10/sup 7/ cm/sec to 5 x 10/sup 7/ cm/sec. Scattered light measurements have shown the transmission loss through a typical spatial filter configuration to be primarily refractive in nature.

  5. Studies of closure phenomena in pinholes irradiated by Nd laser pulses

    International Nuclear Information System (INIS)

    Auerbach, J.M.; Holmes, N.C.; Hunt, J.T.; Linford, G.J.

    1978-01-01

    The plasma closure of spatial filter pinholes is a critical parameter in the performance of high energy glass laser systems. Using 50 to 100 J, 300 psec FWHM laser pulses on the Janus laser, an investigation has been made on closure effects in 300 μm to 500 μm diameter pinholes of various materials and thicknesses. Calorimetry measurements have yielded data on pinhole transmission and intensity loading on the periphery of the pinhole. Ultrafast streak photography measurements indicate effective closure velocities of 2 x 10 7 cm/sec to 5 x 10 7 cm/sec. Scattered light measurements have shown the transmission loss through a typical spatial filter configuration to be primarily refractive in nature

  6. Patient restraining device for the pinhole collimator and gamma scintillation camera

    International Nuclear Information System (INIS)

    Kay, T.D.

    1977-01-01

    A patient restraining device for use with the pinhole collimator of a conventional Gamma Scintillation Camera, the restraining device being made of an adapter ring and a patient holder. The adapter ring is secured directly to the pinhole collimator while the holder is adjustably mounted on the adapter. The adapter ring is so designed to accommodate a variety of holders so as to enable the scanning of many different areas of a patient's anatomy by the scintillation camera

  7. Depth-of-Interaction Compensation Using a Focused-Cut Scintillator for a Pinhole Gamma Camera

    OpenAIRE

    Alhassen, Fares; Kudrolli, Haris; Singh, Bipin; Kim, Sangtaek; Seo, Youngho; Gould, Robert G.; Nagarkar, Vivek V.

    2011-01-01

    Preclinical SPECT offers a powerful means to understand the molecular pathways of drug interactions in animal models by discovering and testing new pharmaceuticals and therapies for potential clinical applications. A combination of high spatial resolution and sensitivity are required in order to map radiotracer uptake within small animals. Pinhole collimators have been investigated, as they offer high resolution by means of image magnification. One of the limitations of pinhole geometries is ...

  8. High-speed photography of light beams transmitted through pinhole targets

    International Nuclear Information System (INIS)

    Yaonan, D.; Haien, He.; Lian, C.; Huifang, Z.; Zhijian, Z.

    1988-01-01

    A method of high speed photography is presented. It was designed and performed in order to study temporal behaviors of plasma closure effects of pinhole targets in laser plasma experiments. A series of high speed photographs were taken for the laser beam transmitted through the pinhole targets. Spatially resolved and integrated temporal histories of closure effects were observed, respectively. Some physical information about closure effect and closure speed have been studied

  9. Comparison of fan beam, slit-slat and multi-pinhole collimators for molecular breast tomosynthesis.

    Science.gov (United States)

    van Roosmalen, Jarno; Beekman, Freek J; Goorden, Marlies C

    2018-05-16

    Recently, we proposed and optimized dedicated multi-pinhole molecular breast tomosynthesis (MBT) that images a lightly compressed breast. As MBT may also be performed with other types of collimators, the aim of this paper is to optimize MBT with fan beam and slit-slat collimators and to compare its performance to that of multi-pinhole MBT to arrive at a truly optimized design. Using analytical expressions, we first optimized fan beam and slit-slat collimator parameters to reach maximum sensitivity at a series of given system resolutions. Additionally, we performed full system simulations of a breast phantom containing several tumours for the optimized designs. We found that at equal system resolution the maximum achievable sensitivity increases from pinhole to slit-slat to fan beam collimation with fan beam and slit-slat MBT having on average a 48% and 20% higher sensitivity than multi-pinhole MBT. Furthermore, by inspecting simulated images and applying a tumour-to-background contrast-to-noise (TB-CNR) analysis, we found that slit-slat collimators underperform with respect to the other collimator types. The fan beam collimators obtained a similar TB-CNR as the pinhole collimators, but the optimum was reached at different system resolutions. For fan beam collimators, a 6-8 mm system resolution was optimal in terms of TB-CNR, while with pinhole collimation highest TB-CNR was reached in the 7-10 mm range.

  10. Modeling erosion of unsaturated compacted bentonite by groundwater flow; pinhole erosion test case

    International Nuclear Information System (INIS)

    Laurila, T.; Sane, P.; Olin, M.; Koskinen, K.

    2012-01-01

    Document available in extended abstract form only. Erosion of compacted clay material by water flow is a critical factor affecting the performance of radioactive waste confinement. Our emphasis in this work is the buffer of KBS-3V concept, proposed to be compacted MX-80 bentonite. Unsaturated erosion occurs during the saturation phase of the EBS, and the main quantity of interest is the total buffer mass carried away by a groundwater flow that induces erosion by forming piping channels near the buffer/rock interface. The purpose of this work is to provide modeling tools to support erosion experiments. Role of modeling is first to interpret experimental observations in terms of processes, and to estimate robustness of experimental results. Secondly, we seek to scale up results from the laboratory scale, particularly to time scales longer than those experimentally accessible. We have performed modeling and data analysis pertaining to tests of unsaturated clay erosion. Pinhole experiments were used to study this erosion case. The main differences to well-understood pinhole erosion tests are that the material is strongly swelling and that the water flow is not determined by the pressure head but by the total flux. Groundwater flow in the buffer is determined by the flux because pressure losses occur overwhelmingly in the surrounding rock, not in the piping channel. We formulate a simple model that links an effective solid diffusivity -based swelling model to erosion by flow on the solid/liquid interface. The swelling model is similar in concept to that developed at KTH, but simpler. Erosion in the model is caused by laminar flow in the pinhole, and happens in a narrow region at the solid/liquid interface where velocity and solid volume fraction overlap. The erosion model can be mapped to erosion by wall shear, and can thus be considered as extension of that classic erosion model. The main quantity defining the behavior of clay erosion in the model is the ratio of

  11. Investigation of imaging properties for submillimeter rectangular pinholes

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Dan, E-mail: dxia@uchicago.edu [The Department of Radiology, The University of Chicago, Chicago, Illinois 60637 (United States); Moore, Stephen C., E-mail: scmoore@bwh.harvard.edu, E-mail: miaepark@bwh.harvard.edu, E-mail: mcervo@bwh.harvard.edu; Park, Mi-Ae, E-mail: scmoore@bwh.harvard.edu, E-mail: miaepark@bwh.harvard.edu, E-mail: mcervo@bwh.harvard.edu; Cervo, Morgan, E-mail: scmoore@bwh.harvard.edu, E-mail: miaepark@bwh.harvard.edu, E-mail: mcervo@bwh.harvard.edu [Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts 02115 (United States); Metzler, Scott D., E-mail: metzler@upenn.edu [The Department of Radiology, The University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)

    2015-12-15

    Purpose: Recently, a multipinhole collimator with inserts that have both rectangular apertures and rectangular fields of view (FOVs) has been proposed for SPECT imaging since it can tile the projection onto the detector efficiently and the FOVs in transverse and axial directions become separable. The purpose of this study is to investigate the image properties of rectangular-aperture pinholes with submillimeter apertures sizes. Methods: In this work, the authors have conducted sensitivity and FOV experiments for 18 replicates of a prototype insert fabricated in platinum/iridium (Pt/Ir) alloy with submillimeter square-apertures. A sin{sup q}θ fit to the experimental sensitivity has been performed for these inserts. For the FOV measurement, the authors have proposed a new formula to calculate the projection intensity of a flood image on the detector, taking into account the penumbra effect. By fitting this formula to the measured projection data, the authors obtained the acceptance angles. Results: The mean (standard deviation) of fitted sensitivity exponents q and effective edge lengths w{sub e} were, respectively, 10.8 (1.8) and 0.38 mm (0.02 mm), which were close to the values, 7.84 and 0.396 mm, obtained from Monte Carlo calculations using the parameters of the designed inserts. For the FOV measurement, the mean (standard deviation) of the transverse and axial acceptances were 35.0° (1.2°) and 30.5° (1.6°), which are in good agreement with the designed values (34.3° and 29.9°). Conclusions: These results showed that the physical properties of the fabricated inserts with submillimeter aperture size matched our design well.

  12. Pinhole diffraction holography for fabrication of high-resolution Fresnel zone plates.

    Science.gov (United States)

    Sarkar, Sankha S; Solak, Harun H; David, Christian; van der Veen, J Friso

    2014-01-27

    Fresnel zone plates (FZPs) play an essential role in high spatial resolution x-ray imaging and analysis of materials in many fields. These diffractive lenses are commonly made by serial writing techniques such as electron beam or focused ion beam lithography. Here we show that pinhole diffraction holography has potential to generate FZP patterns that are free from aberrations and imperfections that may be present in alternative fabrication techniques. In this presented method, FZPs are fabricated by recording interference pattern of a spherical wave generated by diffraction through a pinhole, illuminated with coherent plane wave at extreme ultraviolet (EUV) wavelength. Fundamental and practical issues involved in formation and recording of the interference pattern are considered. It is found that resolution of the produced FZP is directly related to the diameter of the pinhole used and the pinhole size cannot be made arbitrarily small as the transmission of EUV or x-ray light through small pinholes diminishes due to poor refractive index contrast found between materials in these spectral ranges. We also find that the practical restrictions on exposure time due to the light intensity available from current sources directly imposes a limit on the number of zones that can be printed with this method. Therefore a trade-off between the resolution and the FZP diameter exists. Overall, we find that this method can be used to fabricate aberration free FZPs down to a resolution of about 10 nm.

  13. Wireless Synchronization of a Multi-Pinhole Small Animal SPECT Collimation Device With a Clinical Scanner

    Science.gov (United States)

    DiFilippo, Frank P.; Patel, Sagar

    2009-06-01

    A multi-pinhole collimation device for small animal single photon emission computed tomography (SPECT) uses the gamma camera detectors of a standard clinical SPECT scanner. The collimator and animal bed move independently of the detectors, and therefore their motions must be synchronized. One approach is manual triggering of the SPECT acquisition simultaneously with a programmed motion sequence for the device. However, some data blurring and loss of image quality result, and true electronic synchronization is preferred. An off-the-shelf digital gyroscope with integrated Bluetooth interface provides a wireless solution to device synchronization. The sensor attaches to the SPECT gantry and reports its rotational speed to a notebook computer controlling the device. Software processes the rotation data in real-time, averaging the signal and issuing triggers while compensating for baseline drift. Motion commands are sent to the collimation device with minimal delay, within approximately 0.5 second of the start of SPECT gantry rotation. Test scans of a point source demonstrate an increase in true counts and a reduction in background counts compared to manual synchronization. The wireless rotation sensor provides robust synchronization of the collimation device with the clinical SPECT scanner and enhances image quality.

  14. Modeling and characterization of a SPECT system with pinhole collimation for the imaging of small animals

    International Nuclear Information System (INIS)

    Auer, Benjamin

    2017-01-01

    My thesis work focuses on the development of several quantitative reconstruction methods dedicated to small animal Single Photon Emission Computed Tomography (SPECT). The latter is based on modeling the acquisition process of the 4-heads pinhole SPECT system available at Institut Pluridisciplinaire Hubert Curien (IPHC) and fully integrated to the AMISSA platform using Monte Carlo simulations. The system matrix approach, combined with the OS-EM iterative reconstruction algorithm, enabled to characterize the system performances and to compare it to the state of the art. Sensitivity of about 0,027% in the center of the field of view associated to a tomographic spatial resolution of 0, 875 ± 0, 025 mm were obtained. The major drawbacks of Monte Carlo methods led us to develop an efficient and simplified modeling of the physical effects occurring in the subject. My approach based on a system matrix decomposition, associated to a scatter pre-calculated database method, demonstrated an acceptable time for a daily imaging subject follow-up (∼ 1 h), leading to a personalized imaging reconstruction (article accepted). The inherent approximations of the scatter pre-calculated approach (first order scattering modeling and segmented emission) have a moderate impact on the recovery coefficients results, nevertheless a correction of about 10% was achieved. (author) [fr

  15. Measuring Beam Sizes and Ultra-Small Electron Emittances Using an X-ray Pinhole Camera.

    Science.gov (United States)

    Elleaume, P; Fortgang, C; Penel, C; Tarazona, E

    1995-09-01

    A very simple pinhole camera set-up has been built to diagnose the electron beam emittance of the ESRF. The pinhole is placed in the air next to an Al window. An image is obtained with a CCD camera imaging a fluorescent screen. The emittance is deduced from the size of the image. The relationship between the measured beam size and the electron beam emittance depends upon the lattice functions alpha, beta and eta, the screen resolution, pinhole size and photon beam divergence. The set-up is capable of measuring emittances as low as 5 pm rad and is presently routinely used as both an electron beam imaging device and an emittance diagnostic.

  16. An analytical simulation technique for cone-beam CT and pinhole SPECT

    International Nuclear Information System (INIS)

    Zhang Xuezhu; Qi Yujin

    2011-01-01

    This study was aimed at developing an efficient simulation technique with an ordinary PC. The work involved derivation of mathematical operators, analytic phantom generations, and effective analytical projectors developing for cone-beam CT and pinhole SPECT imaging. The computer simulations based on the analytical projectors were developed by ray-tracing method for cone-beam CT and voxel-driven method for pinhole SPECT of degrading blurring. The 3D Shepp-Logan, Jaszczak and Defrise phantoms were used for simulation evaluations and image reconstructions. The reconstructed phantom images were of good accuracy with the phantoms. The results showed that the analytical simulation technique is an efficient tool for studying cone-beam CT and pinhole SPECT imaging. (authors)

  17. Optimising performance of a confocal fluorescence microscope with a differential pinhole

    International Nuclear Information System (INIS)

    Kakade, Rohan; Walker, John G; Phillips, Andrew J

    2016-01-01

    The signal-to-noise ratio (SNR)-resolution trade-off is of great importance to bio-imaging applications where the aim is to image the sample using as little light as possible without significantly sacrificing image quality. In this paper the inherent SNR-resolution tradeoff in Confocal Fluorescence Microscopy (CFM) systems is presented by means of an effective tradeoff curve. A CFM system that employs a differential pinhole detection scheme has recently been shown to offer increased resolution, but at the expense of SNR. An optimum profile for the differential pinhole is identified in this paper that offers improved performance over a conventional (circular pinhole) system. The performance enhancement is illustrated through computer simulation. (paper)

  18. Absolute quantitative total-body small-animal SPECT with focusing pinholes

    International Nuclear Information System (INIS)

    Wu, Chao; Have, Frans van der; Vastenhouw, Brendan; Beekman, Freek J.; Dierckx, Rudi A.J.O.; Paans, Anne M.J.

    2010-01-01

    In pinhole SPECT, attenuation of the photon flux on trajectories between source and pinholes affects quantitative accuracy of reconstructed images. Previously we introduced iterative methods that compensate for image degrading effects of detector and pinhole blurring, pinhole sensitivity and scatter for multi-pinhole SPECT. The aim of this paper is (1) to investigate the accuracy of the Chang algorithm in rodents and (2) to present a practical Chang-based method using body outline contours obtained with optical cameras. Here we develop and experimentally validate a practical method for attenuation correction based on a Chang first-order method. This approach has the advantage that it is employed after, and therefore independently from, iterative reconstruction. Therefore, no new system matrix has to be calculated for each specific animal. Experiments with phantoms and animals were performed with a high-resolution focusing multi-pinhole SPECT system (U-SPECT-II, MILabs, The Netherlands). This SPECT system provides three additional optical camera images of the animal for each SPECT scan from which the animal contour can be estimated. Phantom experiments demonstrated that an average quantification error of -18.7% was reduced to -1.7% when both window-based scatter correction and Chang correction based on the body outline from optical images were applied. Without scatter and attenuation correction, quantification errors in a sacrificed rat containing sources with known activity ranged from -23.6 to -9.3%. These errors were reduced to values between -6.3 and +4.3% (with an average magnitude of 2.1%) after applying scatter and Chang attenuation correction. We conclude that the modified Chang correction based on body contour combined with window-based scatter correction is a practical method for obtaining small-animal SPECT images with high quantitative accuracy. (orig.)

  19. The Nuclear Magnetic Resonance and its utilization in image formation

    International Nuclear Information System (INIS)

    Bonagamba, T.J.; Tannus, A.; Panepucci, H.

    1987-01-01

    Some aspects about Nuclear Magnetic Resonance (as Larmor Theorem, radio frequency pulse, relaxation of spins system) and its utilization in two dimensional image processing with the necessity of a tomography plane are studied. (C.G.C.) [pt

  20. SAR image formation with azimuth interpolation after azimuth transform

    Science.gov (United States)

    Doerry,; Armin W. , Martin; Grant D. , Holzrichter; Michael, W [Albuquerque, NM

    2008-07-08

    Two-dimensional SAR data can be processed into a rectangular grid format by subjecting the SAR data to a Fourier transform operation, and thereafter to a corresponding interpolation operation. Because the interpolation operation follows the Fourier transform operation, the interpolation operation can be simplified, and the effect of interpolation errors can be diminished. This provides for the possibility of both reducing the re-grid processing time, and improving the image quality.

  1. METHODS OF STEREO PAIR IMAGES FORMATION WITH A GIVEN PARALLAX VALUE

    Directory of Open Access Journals (Sweden)

    Viktoriya G. Chafonova

    2014-11-01

    Full Text Available Two new complementary methods of stereo pair images formation are proposed. The first method is based on finding the maximum correlation between the gradient images of the left and right frames. The second one implies the finding of the shift between two corresponding key points of images for a stereo pair found by a detector of point features. These methods give the possibility to set desired values of vertical and horizontal parallaxes for the selected object in the image. Application of these methods makes it possible to measure the parallax values for the objects on the final stereo pair in pixels and / or the percentage of the total image size. It gives the possibility to predict the possible excesses in parallax values while stereo pair printing or projection. The proposed methods are easily automated after object selection, for which a predetermined value of the horizontal parallax will be exposed. Stereo pair images superposition using the key points takes less than one second. The method with correlation application requires a little bit more computing time, but makes it possible to control and superpose undivided anaglyph image. The proposed methods of stereo pair formation can find their application in programs for editing and processing images of a stereo pair, in the monitoring devices for shooting cameras and in the devices for video sequence quality assessment

  2. Image formation simulation for computer-aided inspection planning of machine vision systems

    Science.gov (United States)

    Irgenfried, Stephan; Bergmann, Stephan; Mohammadikaji, Mahsa; Beyerer, Jürgen; Dachsbacher, Carsten; Wörn, Heinz

    2017-06-01

    In this work, a simulation toolset for Computer Aided Inspection Planning (CAIP) of systems for automated optical inspection (AOI) is presented along with a versatile two-robot-setup for verification of simulation and system planning results. The toolset helps to narrow down the large design space of optical inspection systems in interaction with a system expert. The image formation taking place in optical inspection systems is simulated using GPU-based real time graphics and high quality off-line-rendering. The simulation pipeline allows a stepwise optimization of the system, from fast evaluation of surface patch visibility based on real time graphics up to evaluation of image processing results based on off-line global illumination calculation. A focus of this work is on the dependency of simulation quality on measuring, modeling and parameterizing the optical surface properties of the object to be inspected. The applicability to real world problems is demonstrated by taking the example of planning a 3D laser scanner application. Qualitative and quantitative comparison results of synthetic and real images are presented.

  3. Maximum likelihood reconstruction for pinhole SPECT with a displaced center-of-rotation

    International Nuclear Information System (INIS)

    Li, J.; Jaszczak, R.J.; Coleman, R.E.

    1995-01-01

    In this paper, the authors describe the implementation of a maximum likelihood (ML), algorithm using expectation maximization (EM) for pin-hole SPECT with a displaced center-of-rotation. A ray-tracing technique is used in implementing the ML-EM algorithm. The proposed ML-EM algorithm is able to correct the center of rotation displacement which can be characterized by two orthogonal components. The algorithm is tested using experimentally acquired data, and the results demonstrate that the pinhole ML-EM algorithm is able to correct artifacts associated with the center-of-rotation displacement

  4. Resolution improvement and noise reduction in human pinhole SPECT using a multi-ray approach and the SHINE method

    International Nuclear Information System (INIS)

    Seret, A.; Vanhove, C.; Defrise, M.

    2009-01-01

    Purpose: This work aimed at quantifying the gains in spatial resolution and noise that could be achieved when using resolution modelling based on a multi-ray approach and additionally the Statistical and Heuristic Noise Extraction (SHINE) method in human pinhole single photon emission tomography (PH-SPECT). Methods: PH-SPECT of two line phantoms and one homogeneous cylinder were recorded using parameters suited for studies of the human neck area. They were reconstructed using pinhole dedicated ordered subsets expectation maximisation algorithm including a resolution recovery technique based on 7 or 21 rays. Optionally, the SPECT data were SHINE pre-processed. Transverse and axial full widths at half-maximum (FWHM) were obtained from the line phantoms. The noise was quantified using the coefficient of variation (COV) derived from the uniform phantom. Two human PH-SPECT studies of the thyroid (a hot nodule and a very low uptake) were processed with the same algorithms. Results: Depending on the number of iterations, FWHM decreased by 30 to 50% when using the multi-ray approach in the reconstruction process. The SHINE method did not affect the resolution but decreased the COV by at least 20% and by 45% when combined with the multi-ray method. The two human studies illustrated the gain in spatial resolution and the decrease in noise afforded both by the multi-ray reconstruction and the SHINE method. Conclusion: Iterative reconstruction with resolution modelling allows to obtain high resolution human PH-SPECT studies with reduced noise content. The SHINE method affords an additional noise reduction without compromising the resolution. (orig.)

  5. Optical fiber sensors for image formation in radiodiagnostic - preliminary essays

    International Nuclear Information System (INIS)

    Carvalho, Cesar C. de; Werneck, Marcelo M.

    1998-01-01

    This work describes preliminary experiments that will bring subsidies to analyze the capability to implement a system able to capture radiological images with new sensor system, comprised by FOs scanning process and I-CCD camera. These experiments have the main objective to analyze the optical response from FOs bundle, with several typos of scintillators associated with them, when it is submitted to medical x-rays exposition. (author)

  6. Multi-pinhole collimator design for small-object imaging with SiliSPECT: a high-resolution SPECT

    International Nuclear Information System (INIS)

    Shokouhi, S; Peterson, T E; Metzler, S D; Wilson, D W

    2009-01-01

    We have designed a multi-pinhole collimator for a dual-headed, stationary SPECT system that incorporates high-resolution silicon double-sided strip detectors. The compact camera design of our system enables imaging at source-collimator distances between 20 and 30 mm. Our analytical calculations show that using knife-edge pinholes with small-opening angles or cylindrically shaped pinholes in a focused, multi-pinhole configuration in combination with this camera geometry can generate narrow sensitivity profiles across the field of view that can be useful for imaging small objects at high sensitivity and resolution. The current prototype system uses two collimators each containing 127 cylindrically shaped pinholes that are focused toward a target volume. Our goal is imaging objects such as a mouse brain, which could find potential applications in molecular imaging.

  7. Usefulness of pinhole collimator in differential diagnosis of metastatic disease and degenerative joint disease in the vertebrae

    International Nuclear Information System (INIS)

    Kosuda, Shigeru; Kawahara, Syunji; Ishibashi, Akihiko; Tamura, Kohei; Tsukatani, Yasushi; Fujii, Hiroshi; Kubo, Atsushi; Hashimoto, Shozo.

    1989-01-01

    In order to evaluate the diagnostic efficacy of pinhole collimator (PHC) imaging combined with an X-ray for vertebral metastasis, our prospective study has employed receiver operating characteristics (ROC) analysis in 21 patients, 11 with osseous metastasis and 15 with degenerative joint disease in the lumbar vertebrae. PHC imaging provided better anatomic information on the extent of 99m Tc-MDP accumulation. PHC vertebral scintigraphy had a considerable impact on the decision-making process, although with variations and not very satisfactory results among the physicians with little experience. Our study suggests that PHC imaging and X-ray film are useful in differentiating between osseous metastasis and degenerative joint disease in the vertebra. (author)

  8. Effect of streptozotocin-induced diabetes on left ventricular function in adult rats: an in vivo Pinhole Gated SPECT study

    Directory of Open Access Journals (Sweden)

    Weytjens Caroline

    2007-10-01

    Full Text Available Abstract Background Recent studies have suggested that diabetes mellitus (DM may cause left ventricular (LV dysfunction directly resulting in increased susceptibility to heart failure. Using pinhole collimators and advances in data processing, gated SPECT was recently adapted to image the rat heart. The present study was aimed to assess this new imaging technique for quantifying LV function and remodeling from the Streptozotocin (STZ rat model compared to controls. Methods Twenty one rats were randomly assigned to control or diabetic group. Six months after the induction of diabetes by STZ, Pinhole 99 m Tc-sestamibi gated SPECT was performed for determining rat LV volumes and function. Post-mortem histopathologic analysis was performed to evaluate the determinant of LV remodeling in this model. Results After six months, the normalized to body weight LV End-systolic volume was significantly different in diabetic rats compared to controls (0.46 ± 0.02 vs 0.33 ± 0.03 μL/g; p = 0.01. The normalized LV End-diastolic volume was also different in both groups (1.51 ± 0.03 vs 0.88 ± 0.05 μL/g; p = 0.001 and the normalized stroke volume was significantly higher in STZ-rats (1.05 ± 0.02 vs 0.54 ± 0.06 μL/g; p = 0.001. The muscular fibers were thinner at histology in the diabetic rats (0.44 ± 0.07 vs 0.32 ± 0.06 AU; p = 0.01. Conclusion Pinhole 99 m Tc-sestamibi gated SPECT can successfully be applied for the evaluation of cardiac function and remodeling in STZ-induced diabetic rats. In this model, LV volumes were significantly changed compared to a control population, leading to a LV dysfunction. These findings were consistent with the histopathological abnormalities. Finally, these data further suggest the presence of diabetes cardiomyopathy.

  9. WE-DE-206-03: MRI Image Formation - Slice Selection, Phase Encoding, Frequency Encoding, K-Space, SNR

    International Nuclear Information System (INIS)

    Lin, C.

    2016-01-01

    Magnetic resonance imaging (MRI) has become an essential part of clinical imaging due to its ability to render high soft tissue contrast. Instead of ionizing radiation, MRI use strong magnetic field, radio frequency waves and field gradients to create diagnostic useful images. It can be used to image the anatomy and also functional and physiological activities within the human body. Knowledge of the basic physical principles underlying MRI acquisition is vitally important to successful image production and proper image interpretation. This lecture will give an overview of the spin physics, imaging principle of MRI, the hardware of the MRI scanner, and various pulse sequences and their applications. It aims to provide a conceptual foundation to understand the image formation process of a clinical MRI scanner. Learning Objectives: Understand the origin of the MR signal and contrast from the spin physics level. Understand the main hardware components of a MRI scanner and their purposes Understand steps for MR image formation including spatial encoding and image reconstruction Understand the main kinds of MR pulse sequences and their characteristics.

  10. WE-DE-206-03: MRI Image Formation - Slice Selection, Phase Encoding, Frequency Encoding, K-Space, SNR

    Energy Technology Data Exchange (ETDEWEB)

    Lin, C. [Indiana University School of Medicine (United States)

    2016-06-15

    Magnetic resonance imaging (MRI) has become an essential part of clinical imaging due to its ability to render high soft tissue contrast. Instead of ionizing radiation, MRI use strong magnetic field, radio frequency waves and field gradients to create diagnostic useful images. It can be used to image the anatomy and also functional and physiological activities within the human body. Knowledge of the basic physical principles underlying MRI acquisition is vitally important to successful image production and proper image interpretation. This lecture will give an overview of the spin physics, imaging principle of MRI, the hardware of the MRI scanner, and various pulse sequences and their applications. It aims to provide a conceptual foundation to understand the image formation process of a clinical MRI scanner. Learning Objectives: Understand the origin of the MR signal and contrast from the spin physics level. Understand the main hardware components of a MRI scanner and their purposes Understand steps for MR image formation including spatial encoding and image reconstruction Understand the main kinds of MR pulse sequences and their characteristics.

  11. Online information Impact in the virtual destination image formation

    Directory of Open Access Journals (Sweden)

    Célia Maria Conceição Salmim Rafael

    2014-05-01

    Full Text Available The influence of the destination image in the decision process and choice of destination by tourists is transverse to its intangible nature. Recent studies expand and modify the conventional image constructs specifying information sources transmitted through the internet. The scenario resulting from the literature review allows us to understand the importance of experience for touristic activity and theoretical proposition of virtual tourism as "virtual tourist experience", its determinants and its implications for the overall image destination formation. This study presents a literature review base to the empiric research proposal whose general objective comprises the analysis of the influence of factors, such as interactivity, in online communication and contact with virtual tourism experiences online in image destination formation and image destination.

  12. Pinhole single-photon emission tomography reconstruction based on median root prior

    International Nuclear Information System (INIS)

    Sohlberg, Antti; Kuikka, Jyrki T.; Ruotsalainen, Ulla

    2003-01-01

    The maximum likelihood expectation maximisation (ML-EM) algorithm can be used to reduce reconstruction artefacts produced by filtered backprojection (FBP) methods in pinhole single-photon emission tomography (SPET). However, ML-EM suffers from noise propagation along iterations, which leads to quantitatively unpleasant reconstruction results. To avoid this increase in noise, the median root prior (MRP) algorithm for pinhole SPET was implemented. Projection data of a line source and Picker's thyroid phantom were collected using a single-head gamma camera with a pinhole collimator. MRP was added to existing pinhole ML-EM reconstruction algorithm and the phantom studies were reconstructed using MRP, ML-EM and FBP for comparison. Coefficients of variation, contrasts and full-widths at half-maximum were calculated and showed a clear reduction in noise without significant loss of resolution or decrease in contrast when MRP was applied. MRP also produced visually pleasing images even with high iteration numbers, free of the checkerboard-type noise patterns which are typical of ML-EM images. (orig.)

  13. Multi-pinhole SPECT calibration. Influence of data noise and systematic orbit deviations

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Lin; Vunckx, Kathleen; Nuyts, Johan [Katholieke Univ. Leuven (Belgium). Dept. of Nuclear Medicine

    2011-07-01

    Previously it has been proved that the geometry of a multi-pinhole SPECT system with circular orbit can be uniquely determined from a measurement of two point sources, without the knowledge of the distance between them. In this paper, we report that this conclusion only holds if the motion of the camera is perfectly circular. In reality, the detector heads systematically slightly deviate from the circular orbit, which may introduce nonnegligible bias in the calibrated parameters. An analytical linear model was extended to estimate the influence of both data noise and systematic deviations on the accuracy of the calibration and the image quality of the reconstruction. It turns out that applying the knowledge of the distances greatly reduces the reconstruction error, especially in the presence of systematic deviations. In addition, we propose that instead of using the information about the distances between the point sources, it is more straightforward to use the knowledge about the distances between the pinhole apertures during multi-pinhole calibration. The two distance fixing approaches yield similar calibration accuracy, but fixing the inter-pinhole distances is more preferable since it facilitates simultaneous animal-calibration data acquisition. Our theoretical results are supported by reconstruction images of a Jaszczak-type phantom. (orig.)

  14. PINEX-2: pinhole-TV imaging of fuel ejection from an internally vented capsule

    International Nuclear Information System (INIS)

    Berzins, G.J.; Lumpkin, A.H.

    1979-01-01

    The LASL pinhole-intensified TV system was used at the TREAT reactor to image an internally vented, fuel-ejection capsule designed and built by HEDL. Several improvements in the imaging system over PINEX-1 were incorporated. A sequence of 16-ms TV frames shows axial expansion, expulsion of fuel from the pin, and retention of clad integrity during the time of coverage

  15. Stability Measurements for Alignment of the NIF Neutron Imaging System Pinhole Array

    International Nuclear Information System (INIS)

    Fittinghoff, D.N.; Bower, D.E.; Drury, O.B.; Dzenitis, J.M.; Frank, M.; Buckles, R.A.; Munson, C.; Wilde, C.H.

    2011-01-01

    The alignment system for the National Ignition Facility's neutron imaging system has been commissioned and measurements of the relative stability of the 90-315 DIM, the front and the back of the neutron imaging pinhole array and an exploding pusher target have been made using the 90-135 and the 90-258 opposite port alignment systems. Additionally, a laser beam shot from the neutron-imaging Annex and reflected from a mirror at the back of the pinhole array was used to monitor the pointing of the pinhole. Over a twelve hour period, the relative stability of these parts was found to be within ∼ ±18 (micro)m rms even when using manual methods for tracking the position of the objects. For highly visible features, use of basic particle tracking techniques found that the front of the pinhole array was stable relative to the 90-135 opposite port alignment camera to within ±3.4 (micro)m rms. Reregistration, however, of the opposite port alignment systems themselves using the target alignment sensor was found to change the expected position of target chamber center by up to 194 (micro)m.

  16. Reflections on Using Pinhole Photography as a Pedagogical and Methodological Tool with Adolescents in Wild Nature

    Science.gov (United States)

    Socha, Teresa; Potter, Tom; Potter, Stephanie; Jickling, Bob

    2016-01-01

    This paper shares our experiences using pinhole photography with adolescents as both a pedagogical tool to support and deepen adolescent experiences in wild nature, and as a visual methodological tool to elucidate their experiences. Reflecting on a journey that explored the nature-based experiences of two adolescents on a family canoe trip in…

  17. International Youth Diplomacy as a Tool of Russian Image Formation

    Directory of Open Access Journals (Sweden)

    Asadov Babek Rashid ogly

    2014-03-01

    of the country’s youth involved in this process indicates the absence of specific federal programs of youth activity institutions for action on the international stage. However, the analysis of practical results of their activity, contributing to the new forms of international youth activity, which should be considered as the channels for creating the favorable conditions aimed at promoting the positive image of Russia among the international youth, reveals the increasing attention of state and non-governmental organizations to this issue in light of the growing demand. Despite of the fact that the variety of institutional activity forms in the international youth activity and its impact on country’s image is beyond the research interest, today its further studying can open new horizons of discourse regarding the prospects of youth factor, in order to implement effective foreign cultural policy in Russia. Lack of theoretical and practical study of youth diplomacy requires not only consideration of many factors that directly affect the nature of its implementation, but should also focus the attention of scientific community representatives to the need of understanding its perspective role in the foreign cultural policy of the country, therefore, having certain influence on forming the positive image of the country among young people from different cultures and nations.

  18. Assessment of grass root effects on soil piping in sandy soils using the pinhole test

    Science.gov (United States)

    Bernatek-Jakiel, Anita; Vannoppen, Wouter; Poesen, Jean

    2017-10-01

    Soil piping is an important land degradation process that occurs in a wide range of environments. Despite an increasing number of studies on this type of subsurface erosion, the impact of vegetation on piping erosion is still unclear. It can be hypothesized that vegetation, and in particular plant roots, may reduce piping susceptibility of soils because roots of vegetation also control concentrated flow erosion rates or shallow mass movements. Therefore, this paper aims to assess the impact of grass roots on piping erosion susceptibility of a sandy soil. The pinhole test was used as it provides quantitative data on pipeflow discharge, sediment concentration and sediment discharge. Tests were conducted at different hydraulic heads (i.e., 50 mm, 180 mm, 380 mm and 1020 mm). Results showed that the hydraulic head was positively correlated with pipeflow discharge, sediment concentration and sediment discharge, while the presence of grass roots (expressed as root density) was negatively correlated with these pipeflow characteristics. Smaller sediment concentrations and sediment discharges were observed in root-permeated samples compared to root-free samples. When root density exceeds 0.5 kg m- 3, piping erosion rates decreased by 50% compared to root-free soil samples. Moreover, if grass roots are present, the positive correlation between hydraulic head and both sediment discharge and sediment concentration is less pronounced, demonstrating that grass roots become more effective in reducing piping erosion rates at larger hydraulic heads. Overall, this study demonstrates that grass roots are quite efficient in reducing piping erosion rates in sandy soils, even at high hydraulic head (> 1 m). As such, grass roots may therefore be used to efficiently control piping erosion rates in topsoils.

  19. Optimization of a pinhole collimator in a SPECT scintillating fiber detector system: a Monte Carlo analysis

    International Nuclear Information System (INIS)

    Hademenos, G.J.

    1994-01-01

    Monte Carlo simulations were used to optimize the dimensions of a lead pinhole collimator in a photon emission computed tomography (SPECT) system consisting of a line of equally spaced Tc-99m point sources and a plastic scintillating fiber detector. The optimization was performed by evaluating the spatial resolution and scanner sensitivity for each source distribution location and collimator parameter variation. An optimal spatial resolution of 0.43 cm FWHM was observed for a source distribution positioned 2.0 cm from the collimated scintillating fiber detection system with a pinhole radius of 1.0 mm and a collimator thickness of 3.0 cm for a 10,000 emission photon simulation. The optimal sensitivity occurred for a source distance of 2.0 cm, a radius of 3.0 mm and a thickness of 3.0 cm. (author)

  20. "Planaltina in the Hole of Aluminum": production and consumption of pinhole photographs

    Directory of Open Access Journals (Sweden)

    Juliana Soares Mendes

    2015-08-01

    Full Text Available This article analyzes a photographic exhibition consisting of 15 images created by pinhole technique, which stimulates a critical thinking about photojournalism practice and consumption. The exhibition in the internet (www.fosfoto.com and at the Artistic and Historic Museum of Planaltina (Brazilian Federal District happened in May 2009. Participants were asked to interpret the photographs and rewrite temporary captions. The 1.860 proposed captions indicates the public’s interest to participate, discuss and interpret the pictures.

  1. A clinical gamma camera-based pinhole collimated system for high resolution small animal SPECT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Mejia, J.; Galvis-Alonso, O.Y., E-mail: mejia_famerp@yahoo.com.b [Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil). Dept. de Biologia Molecular; Castro, A.A. de; Simoes, M.V. [Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil). Dept. de Clinica Medica; Leite, J.P. [Universidade de Sao Paulo (FMRP/USP), Ribeirao Preto, SP (Brazil). Fac. de Medicina. Dept. de Neurociencias e Ciencias do Comportamento; Braga, J. [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil). Div. de Astrofisica

    2010-11-15

    The main objective of the present study was to upgrade a clinical gamma camera to obtain high resolution tomographic images of small animal organs. The system is based on a clinical gamma camera to which we have adapted a special-purpose pinhole collimator and a device for positioning and rotating the target based on a computer-controlled step motor. We developed a software tool to reconstruct the target's three-dimensional distribution of emission from a set of planar projections, based on the maximum likelihood algorithm. We present details on the hardware and software implementation. We imaged phantoms and heart and kidneys of rats. When using pinhole collimators, the spatial resolution and sensitivity of the imaging system depend on parameters such as the detector-to-collimator and detector-to-target distances and pinhole diameter. In this study, we reached an object voxel size of 0.6 mm and spatial resolution better than 2.4 and 1.7 mm full width at half maximum when 1.5- and 1.0-mm diameter pinholes were used, respectively. Appropriate sensitivity to study the target of interest was attained in both cases. Additionally, we show that as few as 12 projections are sufficient to attain good quality reconstructions, a result that implies a significant reduction of acquisition time and opens the possibility for radiotracer dynamic studies. In conclusion, a high resolution single photon emission computed tomography (SPECT) system was developed using a commercial clinical gamma camera, allowing the acquisition of detailed volumetric images of small animal organs. This type of system has important implications for research areas such as Cardiology, Neurology or Oncology. (author)

  2. Depth-of-Interaction Compensation Using a Focused-Cut Scintillator for a Pinhole Gamma Camera

    Science.gov (United States)

    Alhassen, Fares; Kudrolli, Haris; Singh, Bipin; Kim, Sangtaek; Seo, Youngho; Gould, Robert G.; Nagarkar, Vivek V.

    2011-06-01

    Preclinical SPECT offers a powerful means to understand the molecular pathways of drug interactions in animal models by discovering and testing new pharmaceuticals and therapies for potential clinical applications. A combination of high spatial resolution and sensitivity are required in order to map radiotracer uptake within small animals. Pinhole collimators have been investigated, as they offer high resolution by means of image magnification. One of the limitations of pinhole geometries is that increased magnification causes some rays to travel through the detection scintillator at steep angles, introducing parallax errors due to variable depth-of-interaction in scintillator material, especially towards the edges of the detector field of view. These parallax errors ultimately limit the resolution of pinhole preclinical SPECT systems, especially for higher energy isotopes that can easily penetrate through millimeters of scintillator material. A pixellated, focused-cut (FC) scintillator, with its pixels laser-cut so that they are collinear with incoming rays, can potentially compensate for these parallax errors and thus improve the system resolution. We performed the first experimental evaluation of a newly developed focused-cut scintillator. We scanned a Tc-99 m source across the field of view of pinhole gamma camera with a continuous scintillator, a conventional “straight-cut” (SC) pixellated scintillator, and a focused-cut scintillator, each coupled to an electron-multiplying charge coupled device (EMCCD) detector by a fiber-optic taper, and compared the measured full-width half-maximum (FWHM) values. We show that the FWHMs of the focused-cut scintillator projections are comparable to the FWHMs of the thinner SC scintillator, indicating the effectiveness of the focused-cut scintillator in compensating parallax errors.

  3. Depth-of-Interaction Compensation Using a Focused-Cut Scintillator for a Pinhole Gamma Camera.

    Science.gov (United States)

    Alhassen, Fares; Kudrolli, Haris; Singh, Bipin; Kim, Sangtaek; Seo, Youngho; Gould, Robert G; Nagarkar, Vivek V

    2011-06-01

    Preclinical SPECT offers a powerful means to understand the molecular pathways of drug interactions in animal models by discovering and testing new pharmaceuticals and therapies for potential clinical applications. A combination of high spatial resolution and sensitivity are required in order to map radiotracer uptake within small animals. Pinhole collimators have been investigated, as they offer high resolution by means of image magnification. One of the limitations of pinhole geometries is that increased magnification causes some rays to travel through the detection scintillator at steep angles, introducing parallax errors due to variable depth-of-interaction in scintillator material, especially towards the edges of the detector field of view. These parallax errors ultimately limit the resolution of pinhole preclinical SPECT systems, especially for higher energy isotopes that can easily penetrate through millimeters of scintillator material. A pixellated, focused-cut (FC) scintillator, with its pixels laser-cut so that they are collinear with incoming rays, can potentially compensate for these parallax errors and thus improve the system resolution. We performed the first experimental evaluation of a newly developed focused-cut scintillator. We scanned a Tc-99m source across the field of view of pinhole gamma camera with a continuous scintillator, a conventional "straight-cut" (SC) pixellated scintillator, and a focused-cut scintillator, each coupled to an electron-multiplying charge coupled device (EMCCD) detector by a fiber-optic taper, and compared the measured full-width half-maximum (FWHM) values. We show that the FWHMs of the focused-cut scintillator projections are comparable to the FWHMs of the thinner SC scintillator, indicating the effectiveness of the focused-cut scintillator in compensating parallax errors.

  4. Real-time monitoring and verification of in vivo high dose rate brachytherapy using a pinhole camera

    International Nuclear Information System (INIS)

    Duan, Jun; Macey, Daniel J.; Pareek, Prem N.; Brezovich, Ivan A.

    2001-01-01

    We investigated a pinhole imaging system for independent in vivo monitoring and verification of high dose rate (HDR) brachytherapy treatment. The system consists of a high-resolution pinhole collimator, an x-ray fluoroscope, and a standard radiographic screen-film combination. Autofluoroscopy provides real-time images of the in vivo Ir-192 HDR source for monitoring the source location and movement, whereas autoradiography generates a permanent record of source positions on film. Dual-pinhole autoradiographs render stereo-shifted source images that can be used to reconstruct the source dwell positions in three dimensions. The dynamic range and spatial resolution of the system were studied with a polystyrene phantom using a range of source strengths and dwell times. For the range of source activity used in HDR brachytherapy, a 0.5 mm diameter pinhole produced sharp fluoroscopic images of the source within the dynamic range of the fluoroscope. With a source-to-film distance of 35 cm and a 400 speed screen-film combination, the same pinhole yielded well recognizable images of a 281.2 GBq (7.60 Ci) Ir-192 source for dwell times in the typical clinical range of 2 to 400 s. This 0.5 mm diameter pinhole could clearly resolve source positions separated by lateral displacements as small as 1 mm. Using a simple reconstruction algorithm, dwell positions in a phantom were derived from stereo-shifted dual-pinhole images and compared to the known positions. The agreement was better than 1 mm. A preliminary study of a patient undergoing HDR treatment for cervical cancer suggests that the imaging method is clinically feasible. Based on these studies we believe that the pinhole imaging method is capable of providing independent and reliable real-time monitoring and verification for HDR brachytherapy

  5. 3D dual-virtual-pinhole assisted single particle tracking microscopy

    International Nuclear Information System (INIS)

    Ma, Ye; Wang, Yifan; Zhou, Xin; Kuang, Cuifang; Liu, Xu

    2014-01-01

    We propose a novel approach for high-speed, three-dimensional single particle tracking (SPT), which we refer to as dual-virtual-pinhole assisted single particle tracking microscopy (DVPaSPTM). DVPaSPTM system can obtain axial information of the sample without optical or mechanical depth scanning, so as to offer numbers of advantages including faster imaging, improved efficiency and a great reduction of photobleaching and phototoxicity. In addition, by the use of the dual-virtual-pinhole, the effect that the quantum yield exerts to the fluorescent signal can be eliminated, which makes the measurement independent of the surroundings and increases the accuracy of the result. DVPaSPTM system measures the intensity within different virtual pinholes of which the radii are given by the host computer. Axial information of fluorophores can be measured by the axial response curve through the ratio of intensity signals. We demonstrated the feasibility of the proposed method by a series of experiments. Results showed that the standard deviation of the axial measurement was 19.2 nm over a 2.5 μm range with 30 ms temporal resolution. (papers)

  6. System geometry optimization for molecular breast tomosynthesis with focusing multi-pinhole collimators

    Science.gov (United States)

    van Roosmalen, Jarno; Beekman, Freek J.; Goorden, Marlies C.

    2018-01-01

    Imaging of 99mTc-labelled tracers is gaining popularity for detecting breast tumours. Recently, we proposed a novel design for molecular breast tomosynthesis (MBT) based on two sliding focusing multi-pinhole collimators that scan a modestly compressed breast. Simulation studies indicate that MBT has the potential to improve the tumour-to-background contrast-to-noise ratio significantly over state-of-the-art planar molecular breast imaging. The aim of the present paper is to optimize the collimator-detector geometry of MBT. Using analytical models, we first optimized sensitivity at different fixed system resolutions (ranging from 5 to 12 mm) by tuning the pinhole diameters and the distance between breast and detector for a whole series of automatically generated multi-pinhole designs. We evaluated both MBT with a conventional continuous crystal detector with 3.2 mm intrinsic resolution and with a pixelated detector with 1.6 mm pixels. Subsequently, full system simulations of a breast phantom containing several lesions were performed for the optimized geometry at each system resolution for both types of detector. From these simulations, we found that tumour-to-background contrast-to-noise ratio was highest for systems in the 7 mm-10 mm system resolution range over which it hardly varied. No significant differences between the two detector types were found.

  7. X-ray pinhole camera setups used in the Atomki ECR Laboratory for plasma diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Rácz, R., E-mail: rracz@atomki.hu; Biri, S.; Pálinkás, J. [Institute for Nuclear Research (Atomki), Hungarian Academy of Sciences, Bem tér 18/C, H-4026 Debrecen (Hungary); Mascali, D.; Castro, G.; Caliri, C.; Gammino, S. [Instituto Nazionale di Fisica Nucleare—Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); Romano, F. P. [Instituto Nazionale di Fisica Nucleare—Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); CNR, Istituto per i Beni Archeologici e Monumentali, Via Biblioteca 4, 95124 Catania (Italy)

    2016-02-15

    Imaging of the electron cyclotron resonance (ECR) plasmas by using CCD camera in combination with a pinhole is a non-destructive diagnostics method to record the strongly inhomogeneous spatial density distribution of the X-ray emitted by the plasma and by the chamber walls. This method can provide information on the location of the collisions between warm electrons and multiple charged ions/atoms, opening the possibility to investigate the direct effect of the ion source tuning parameters to the plasma structure. The first successful experiment with a pinhole X-ray camera was carried out in the Atomki ECR Laboratory more than 10 years ago. The goal of that experiment was to make the first ECR X-ray photos and to carry out simple studies on the effect of some setting parameters (magnetic field, extraction, disc voltage, gas mixing, etc.). Recently, intensive efforts were taken to investigate now the effect of different RF resonant modes to the plasma structure. Comparing to the 2002 experiment, this campaign used wider instrumental stock: CCD camera with a lead pinhole was placed at the injection side allowing X-ray imaging and beam extraction simultaneously. Additionally, Silicon Drift Detector (SDD) and High Purity Germanium (HPGe) detectors were installed to characterize the volumetric X-ray emission rate caused by the warm and hot electron domains. In this paper, detailed comparison study on the two X-ray camera and detector setups and also on the technical and scientific goals of the experiments is presented.

  8. Monte Carlo evaluation of scattering correction methods in 131I studies using pinhole collimator

    International Nuclear Information System (INIS)

    López Díaz, Adlin; San Pedro, Aley Palau; Martín Escuela, Juan Miguel; Rodríguez Pérez, Sunay; Díaz García, Angelina

    2017-01-01

    Scattering is quite important for image activity quantification. In order to study the scattering factors and the efficacy of 3 multiple window energy scatter correction methods during 131 I thyroid studies with a pinhole collimator (5 mm hole) a Monte Carlo simulation (MC) was developed. The GAMOS MC code was used to model the gamma camera and the thyroid source geometry. First, to validate the MC gamma camera pinhole-source model, sensibility in air and water of the simulated and measured thyroid phantom geometries were compared. Next, simulations to investigate scattering and the result of triple energy (TEW), Double energy (DW) and Reduced double (RDW) energy windows correction methods were performed for different thyroid sizes and depth thicknesses. The relative discrepancies to MC real event were evaluated. Results: The accuracy of the GAMOS MC model was verified and validated. The image’s scattering contribution was significant, between 27-40 %. The discrepancies between 3 multiple window energy correction method results were significant (between 9-86 %). The Reduce Double Window methods (15%) provide discrepancies of 9-16 %. Conclusions: For the simulated thyroid geometry with pinhole, the RDW (15 %) was the most effective. (author)

  9. X-ray pinhole camera setups used in the Atomki ECR Laboratory for plasma diagnostics.

    Science.gov (United States)

    Rácz, R; Biri, S; Pálinkás, J; Mascali, D; Castro, G; Caliri, C; Romano, F P; Gammino, S

    2016-02-01

    Imaging of the electron cyclotron resonance (ECR) plasmas by using CCD camera in combination with a pinhole is a non-destructive diagnostics method to record the strongly inhomogeneous spatial density distribution of the X-ray emitted by the plasma and by the chamber walls. This method can provide information on the location of the collisions between warm electrons and multiple charged ions/atoms, opening the possibility to investigate the direct effect of the ion source tuning parameters to the plasma structure. The first successful experiment with a pinhole X-ray camera was carried out in the Atomki ECR Laboratory more than 10 years ago. The goal of that experiment was to make the first ECR X-ray photos and to carry out simple studies on the effect of some setting parameters (magnetic field, extraction, disc voltage, gas mixing, etc.). Recently, intensive efforts were taken to investigate now the effect of different RF resonant modes to the plasma structure. Comparing to the 2002 experiment, this campaign used wider instrumental stock: CCD camera with a lead pinhole was placed at the injection side allowing X-ray imaging and beam extraction simultaneously. Additionally, Silicon Drift Detector (SDD) and High Purity Germanium (HPGe) detectors were installed to characterize the volumetric X-ray emission rate caused by the warm and hot electron domains. In this paper, detailed comparison study on the two X-ray camera and detector setups and also on the technical and scientific goals of the experiments is presented.

  10. Wholebody and pinhole bone scan manifestations of reiter's syndorme: distribution pattern and specific and early signs

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S. H.; Chung, S. K.; Park, Y. H.; Lee, S. Y.; Sohn, H. S.; Han, B. H.; Bahk, Y. W. [College of Medicine, Catholic Univ., Seoul (Korea, Republic of)

    1998-07-01

    We wish to describe the characteristics panoramic wholebody bone distribution, and specific and preradiographic pinhole bone scan signs of Reiter's syndrome(RS) featured by pauciarthritis and enthesopathies in and about weight-bearing joints of the lower extremities and axial bones. We analyzed 55 sets of wholebody and pinhole bone scintigraphs of 55 patients with RS. The population was 44 men and 11 women with age ranging from 15 to 52 yr (mean=29.3). The scintigraphy was performed 2-2.5 hr pi of Tc-99m-HDP using a single-head gamma camera with a LEHR collimator and a 4-mm pinhole collimator for the wholebody and pinhole scintigraphy, respectively. We found 223 lesions with increased tracer uptake in total. Wholebody scans showed asymmetric pauciarticular distribution in weight bearing joints and periarticular entheses in the lower extremities in 63.2% (calcaneus=24.2%, ankle=8.1%, tibia=8.1% and others). The sternum, sacroiliac joint and spine were involved in 8.5%, 5.8% and 4.5%, respectively. Pinhole scan portrayed many specific signs including the 'tear-drop' sign of paravertebral ossification. 'whiskers' sign of femoral osteophytes and 'knuckle bone' sign of sausage digit. Twenty-four lesions (10.8%) showed preradiogrpahic signs in symptomatic ehthesopathies mostly in the calcaneus and proximal tibia. Nine cases with calcaneal enthesopathies and four cases with proximal tibial enthesopathy without radiographic bone change showed intense tracer uptake. Wholebody and pinhole magnification scans were useful in studying RS. The asymmetric pauciarticular distribution in the weight-bearing bones with enthesopathies was characteristic. Pinhole scan portrayed many specific signs and was sensitive permitting accurate preradiographic diagnosis in many cases.

  11. Whole-body and pinhole bone scintigraphic manifestations of Reiter`s syndrome: distribution patterns and early and characteristic signs

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung-Hoon; Chung, Soo-Kyo; Park, Young-Ha; Lee, Sung-Yong; Sohn, Hyung-Sun [Department of Nuclear Medicine, Catholic University Hospitals, Seoul (Korea, Republic of); Bahk, Yong-Whee [Department of Radiology, Samsung Cheil Hospital, Sungkyunkwan University College of Medicine, Seoul (Korea, Republic of)

    1999-02-01

    The characteristic whole-body and pinhole scintigraphic manifestations of osteo-enthesopathy and arthropathy in Reiter`s syndrome (RS) are described, with an emphasis on early diagnosis. We analysed 59 sets of whole-body and pinhole bone scintigrams of 59 patients with RS. The population comprised 47 men and 12 women with an age range from 15 to 53 years (mean=29.4). Bone scintigraphy was carried out 2-2.5 h after intravenous injection of technetium-99m hydroxydiphosphonate using a single-head gamma camera (Siemens Orbiter Model 6601) with a low-energy high-resolution and a 4-mm pinhole collimator for whole-body and pinhole scintigraphy, respectively. In total 262 lesions of osteo-enthesopathy and arthritis were detected on 59 whole-body scintigrams, an incidence of 4.4 lesions per patient. As anticipated, the lesional distribution was asymmetrical: 68% were in the lower limb skeleton and 32% in the axial and upper limb skeleton. Pinhole bone scintigraphy, applied selectively to one region of interest in each case, enabled us to accurately diagnose arthritis and osteo-enthesopathy. It was noteworthy that osteo-enthesopathy, alone or in combination with arthritis, occurred in 78.9%, and had a strong predilection for the foot bones, especially the calcaneus (25.6%). Pinhole scintigraphy detected enthesopathy in the absence of radiographic alteration in 14.1% of cases and portrayed characteristic signs of RS in 6.9%. Whole-body bone scintigraphy augmented with pinhole scintigraphy was found to be useful in order to panoramically display the systemic involvement pattern, to assess the characteristic bone and articular alterations and to detect early signs of RS. (orig.) With 10 figs., 3 tabs., 19 refs.

  12. Pinhole aperture point backlighter development experiments on Trident, 9-13, 2001

    International Nuclear Information System (INIS)

    Lanier, N.E.; Murphy, Thomas J.

    2001-01-01

    Pinhole aperture point backlighter (PAPBL) imaging has been used on experiments on Omega, but results have been compromised by large backgrounds. This technique has advantages over traditional area backlighting/pinhole imaging, and the Omega experiments could benefit from this capability, but Omega time is expensive and not the place for developing diagnostic techniques if they can be developed on Trident instead. PAPBL, shot from Direct Drive Cylinder Mix experiments on Omega (DDCYLMIX 00-1, January 18 and 19, 2000). (See LA-UR-00-4187, Post-Shot Report, Direct Drive Cylinder Mix). In this campaign, they used Trident to obtain clean PAPBL images. Having accomplished that, they attempted to replicate the noise environment of Omega by producing hot electrons and having them impinge on material to produce high-energy x-rays similar to those that might be produced by hot electrons impinging on diagnostics or target positioner components on Omega. Backlighter target design was based, to some degree, on that shown by Bullock et al. at the 42nd Annual APS-DPP Meeting in Quebec City, Quebec, Canada, October 23-27, 2000. (A.B. Bullock et al., Bull. Am. Phys. Soc. 45,(7) 359 (2000); A.B. Bullock et al., Rev. Sci. Instrum. 72, 690 (2001).) We accomplished this to some degree and then attempted, with some success, to obtain a good PAPBL image in the presence of this noise. Results of this work suggest methods that might reduce the background noise in Omega PAPBL images. The goals are to obtain a pinhole aperture point backlighter (PAPBL) image on Trident and develop a method to simulate the high-energy background contribution to PAPBL imnages seen on Omega experients in order to allow future experiments to optimize signal-to-noise in PAPBL imaging.

  13. Robust Pinhole-free Li3N Solid Electrolyte Grown from Molten Lithium

    Directory of Open Access Journals (Sweden)

    Yanbin Li

    2017-12-01

    Full Text Available Lithium metal is the ultimate anode choice for high energy density rechargeable lithium batteries. However, it suffers from inferior electrochemical performance and safety issues due to its high reactivity and the growth of lithium dendrites. It has long been desired to develop a materials coating on Li metal, which is pinhole-free, mechanically robust without fracture during Li metal deposition and stripping, and chemically stable against Li metal and liquid electrolytes, all while maintaining adequate ionic conductivity. However, such an ideal material coating has yet to be found. Here we report a novel synthesis method by reacting clean molten lithium foil directly with pure nitrogen gas to generate instantaneously a pinhole-free and ionically conductive α-Li3N film directly bonded onto Li metal foil. The film consists of highly textured large Li3N grains (tens of μm with (001 crystalline planes parallel to the Li metal surface. The bonding between textured grains is strong, resulting in a mechanically robust film which does not crack even when bent to a 0.8 cm curvature radius and is found to maintain pinhole-free coverage during Li metal deposition and stripping. The measured ionic conductivity is up to 5.2 × 10–4 S cm–1, sufficient for maintaining regular current densities for controllable film thicknesses ranging from 2 to 30 μm. This Li3N coating is chemically stable, isolating the reactive metallic lithium from liquid electrolyte, prevents continuous electrolyte consumption during battery cycling, and promotes dendrite-free uniform lithium plating/stripping underneath. We demonstrated Li|Li4Ti5O12 cells with stable and flat potential profiles for 500 cycles without capacity decay or an increase in potential hysteresis.

  14. Imaging of dopamine transporters in rats using high-resolution pinhole single-photon emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Booij, Jan; Bruin, Kora de; Habraken, Jan B.A. [Department of Nuclear Medicine, F2N, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam (Netherlands); Voorn, Pieter [Department of Anatomy, Vrije Universiteit Medical Center, Amsterdam (Netherlands)

    2002-09-01

    To date, the vast majority of investigations on the dopaminergic system in small animals have been in vitro studies. In comparison with in vitro studies, single-photon emission tomography (SPET) or positron emission tomography (PET) imaging of the dopaminergic system in small animals has the advantage of permitting repeated studies within the same group of animals. Dopamine transporter imaging is a valuable non-invasive tool with which to investigate the integrity of dopaminergic neurons. The purpose of this study was to investigate the feasibility of assessing dopamine transporter density semi-quantitatively in rats using a recently developed high-resolution pinhole SPET system. This system was built exclusively for imaging of small animals. In this unique single-pinhole system, the animal rotates instead of the collimated detector. The system has proven to have a high spatial resolution. We performed SPET imaging with [{sup 123}I]FP-CIT to quantify striatal dopamine transporters in rat brain. In all seven studied control rats, symmetrical striatal binding to dopamine transporters was seen 2 h after injection of the radiotracer, with striatal-to-cerebellar binding ratios of approximately 3.5. In addition, test/retest variability of the striatal-to-cerebellar binding ratios was studied and found to be 14.5%. Finally, in unilaterally 6-hydroxydopamine-lesioned rats, striatal binding was only visible on the non-lesioned side. Quantitative analysis revealed that striatal-to-cerebellar SPET ratios were significantly lower on the lesioned (mean binding ratio 2.2{+-}0.2) than on the non-lesioned (mean ratio 3.1{+-}0.4) side. The preliminary results of this study indicate that semi-quantitative assessment of striatal dopamine transporter density using our recently developed high-resolution single-pinhole SPET system is feasible in living rat brain. (orig.)

  15. Microlens Array/Pinhole Mask to Suppress Starlight for Direct Exoplanet Detection

    Science.gov (United States)

    Zimmerman, Neil

    Direct imaging of habitable exoplanets is a key priority of NASA’s Astrophysics roadmap, “Enduring Quests, Daring Visions.” A coronagraphic starlight suppression system situated on a large space telescope offers a viable path to achieving this goal. This type of instrument is central to both the LUVOIR and HabEx mission concepts currently under study for the 2020 Decadal Survey. To directly image an Earth-like exoplanet, an instrument must be sensitive to objects ten billion times dimmer than their parent star. Advanced coronagraphs are designed to modify the shape of the star’s image so that it does not overwhelm the planet's light. Coronagraphs are complex to design and fabricate, tend to sacrifice a significant portion of the exoplanet light entering the telescope, and are highly sensitive to errors in the telescope. The proposed work reduces the demands on the coronagraph and its sensitivity to errors in the telescope, by changing how we implement optics in the spectrograph following the coronagraph. Through optical analysis and modeling, we have found that a microlens array with a specially arranged pattern of pinholes can suppress residual starlight in the scientific image after the coronagraph by more than two orders of magnitude. This added layer of starlight rejection could be used to relax the extreme observatory stability requirements for exo-Earth imaging applications, for example shifting the wavefront stability requirement from a few picometers to a few nanometers. Ultimately this translates to the instrument detecting and spectrally characterizing more exoplanets than a conventional coronagraph system. This microlens/pinhole concept is also compatible with starshadebased starlight suppression systems. The proposed microlens/pinhole device is entirely passive and augments the performance of existing coronagraph designs, while potentially reducing their cost and risk for mission implementation. Our APRA proposal would support a testbed

  16. Reconstruction of multiple-pinhole micro-SPECT data using origin ensembles.

    Science.gov (United States)

    Lyon, Morgan C; Sitek, Arkadiusz; Metzler, Scott D; Moore, Stephen C

    2016-10-01

    The authors are currently developing a dual-resolution multiple-pinhole microSPECT imaging system based on three large NaI(Tl) gamma cameras. Two multiple-pinhole tungsten collimator tubes will be used sequentially for whole-body "scout" imaging of a mouse, followed by high-resolution (hi-res) imaging of an organ of interest, such as the heart or brain. Ideally, the whole-body image will be reconstructed in real time such that data need only be acquired until the area of interest can be visualized well-enough to determine positioning for the hi-res scan. The authors investigated the utility of the origin ensemble (OE) algorithm for online and offline reconstructions of the scout data. This algorithm operates directly in image space, and can provide estimates of image uncertainty, along with reconstructed images. Techniques for accelerating the OE reconstruction were also introduced and evaluated. System matrices were calculated for our 39-pinhole scout collimator design. SPECT projections were simulated for a range of count levels using the MOBY digital mouse phantom. Simulated data were used for a comparison of OE and maximum-likelihood expectation maximization (MLEM) reconstructions. The OE algorithm convergence was evaluated by calculating the total-image entropy and by measuring the counts in a volume-of-interest (VOI) containing the heart. Total-image entropy was also calculated for simulated MOBY data reconstructed using OE with various levels of parallelization. For VOI measurements in the heart, liver, bladder, and soft-tissue, MLEM and OE reconstructed images agreed within 6%. Image entropy converged after ∼2000 iterations of OE, while the counts in the heart converged earlier at ∼200 iterations of OE. An accelerated version of OE completed 1000 iterations in <9 min for a 6.8M count data set, with some loss of image entropy performance, whereas the same dataset required ∼79 min to complete 1000 iterations of conventional OE. A combination of the two

  17. Differential diagnosis of trampoline fracture from osteomyelitis by bone scan with pinhole collimator.

    Science.gov (United States)

    Gauthé, Mathieu; Mestas, Danielle; Canavese, Federico; Samba, Antoine; Cachin, Florent

    2014-02-01

    A 2-year-old girl with recent history of trampoline fall presented to the A&E Department for complete functional impairment of the left lower extremity and fever. Blood examination revealed an inflammatory syndrome, while plain radiographs were normal. As magnetic resonance imaging was unavailable, a bone scintigraphy was performed. While standard acquisition found an intense uptake focused on the left proximal tibial metaphysis whose appearance was suggestive of acute hematogenous osteomyelitis, complementary acquisition with the pinhole collimator demonstrated that this abnormal uptake was clearly distinct from the cartilage growth plate. One month follow-up radiographs showed a fracture that confirmed the diagnosis of trampoline fracture.

  18. Investigating Image Formation with a Camera Obscura: a Study in Initial Primary Science Teacher Education

    Science.gov (United States)

    Muñoz-Franco, Granada; Criado, Ana María; García-Carmona, Antonio

    2018-04-01

    This article presents the results of a qualitative study aimed at determining the effectiveness of the camera obscura as a didactic tool to understand image formation (i.e., how it is possible to see objects and how their image is formed on the retina, and what the image formed on the retina is like compared to the object observed) in a context of scientific inquiry. The study involved 104 prospective primary teachers (PPTs) who were being trained in science teaching. To assess the effectiveness of this tool, an open questionnaire was applied before (pre-test) and after (post-test) the educational intervention. The data were analyzed by combining methods of inter- and intra-rater analysis. The results showed that more than half of the PPTs advanced in their ideas towards the desirable level of knowledge in relation to the phenomena studied. The conclusion reached is that the camera obscura, used in a context of scientific inquiry, is a useful tool for PPTs to improve their knowledge about image formation and experience in the first person an authentic scientific inquiry during their teacher training.

  19. Degradation sources of CdTe thin film PV: CdCl{sub 2} residue and shunting pinholes

    Energy Technology Data Exchange (ETDEWEB)

    Gorji, Nima E. [University of Bologna, Department of Electrical, Electronics and Information Engineering, Bologna (Italy)

    2014-09-15

    The present work considers two observable phenomena through the experimental fabrication and electrical characterization of the rf-sputtered CdS/CdTe thin film solar cells that extremely reduce the overall conversion efficiency of the device: CdCl{sub 2} residue on the surface of the semiconductor and shunting pinholes. The former happens through nonuniform treatment of the As-deposited solar cells before annealing at high temperature and the latter occurs by shunting pinholes when the cell surface is shunted by defects, wire-like pathways or scratches on the metallic back contact caused from the external contacts. Such physical problems may be quite common in the experimental activities and reduce the performance down to 4-5 % which leads to dismantle the device despite its precise fabrication. We present our electrical characterization on the samples that received wet CdCl{sub 2} surface treatment (uniform or nonuniform) and are damaged by the pinholes. (orig.)

  20. Air-supplied pinhole discharge in aqueous solution for the inactivation of Escherichia coli

    Science.gov (United States)

    Suganuma, Ryota; Yasuoka, Koichi

    2018-04-01

    An air-supplied pinhole discharge in aqueous solution has been developed to provide a short-lived and odorless bactericide to replace current conventional disinfectants such as O3, ClO-, HClO, and ClO2. The pinhole discharge that was initiated inside a water bubble generated hydrogen peroxide (H2O2) and nitrous acid (HNO2) simultaneously. The concentrations of H2O2, HNO2, and HNO3 were 16.3, 13.9, and 17.4 mg/L, respectively when flow rates of NaCl solution and air were 72 and 12.5 mL/min, respectively. The pH value of the solution was 3.87, and HO2 radicals were generated from the reaction of H2O2 with HNO2. The efficacy of sterilization of discharge-treated water was evaluated by changing the acetic solutions. A 4-orders-of-magnitude decrease in Escherichia coli survival rate was observed after treatment with a sodium citrate solution of pH 3.2 for 60 s.

  1. Evaluation of commercial nickel-phosphorus coating for ultracold neutron guides using a pinhole bottling method

    Science.gov (United States)

    Pattie, R. W.; Adamek, E. R.; Brenner, T.; Brandt, A.; Broussard, L. J.; Callahan, N. B.; Clayton, S. M.; Cude-Woods, C.; Currie, S. A.; Geltenbort, P.; Ito, T. M.; Lauer, T.; Liu, C. Y.; Majewski, J.; Makela, M.; Masuda, Y.; Morris, C. L.; Ramsey, J. C.; Salvat, D. J.; Saunders, A.; Schroffenegger, J.; Tang, Z.; Wei, W.; Wang, Z.; Watkins, E.; Young, A. R.; Zeck, B. A.

    2017-11-01

    We report on the evaluation of commercial electroless nickel phosphorus (NiP) coatings for ultracold neutron (UCN) transport and storage. The material potential of 50 μm thick NiP coatings on stainless steel and aluminum substrates was measured to be VF = 213(5 . 2) neV using the time-of-flight spectrometer ASTERIX at the Lujan Center. The loss per bounce probability was measured in pinhole bottling experiments carried out at ultracold neutron sources at Los Alamos Neutron Science Center and the Institut Laue-Langevin. For these tests a new guide coupling design was used to minimize gaps between the guide sections. The observed UCN loss in the bottle was interpreted in terms of an energy independent effective loss per bounce, which is the appropriate model when gaps in the system and upscattering are the dominate loss mechanisms, yielding a loss per bounce of 1 . 3(1) × 10-4. We also present a detailed discussion of the pinhole bottling methodology and an energy dependent analysis of the experimental results.

  2. Accelerated median root prior reconstruction for pinhole single-photon emission tomography (SPET)

    Energy Technology Data Exchange (ETDEWEB)

    Sohlberg, Antti [Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital, PO Box 1777 FIN-70211, Kuopio (Finland); Ruotsalainen, Ulla [Institute of Signal Processing, DMI, Tampere University of Technology, PO Box 553 FIN-33101, Tampere (Finland); Watabe, Hiroshi [National Cardiovascular Center Research Institute, 5-7-1 Fujisihro-dai, Suita City, Osaka 565-8565 (Japan); Iida, Hidehiro [National Cardiovascular Center Research Institute, 5-7-1 Fujisihro-dai, Suita City, Osaka 565-8565 (Japan); Kuikka, Jyrki T [Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital, PO Box 1777 FIN-70211, Kuopio (Finland)

    2003-07-07

    Pinhole collimation can be used to improve spatial resolution in SPET. However, the resolution improvement is achieved at the cost of reduced sensitivity, which leads to projection images with poor statistics. Images reconstructed from these projections using the maximum likelihood expectation maximization (ML-EM) algorithms, which have been used to reduce the artefacts generated by the filtered backprojection (FBP) based reconstruction, suffer from noise/bias trade-off: noise contaminates the images at high iteration numbers, whereas early abortion of the algorithm produces images that are excessively smooth and biased towards the initial estimate of the algorithm. To limit the noise accumulation we propose the use of the pinhole median root prior (PH-MRP) reconstruction algorithm. MRP is a Bayesian reconstruction method that has already been used in PET imaging and shown to possess good noise reduction and edge preservation properties. In this study the PH-MRP algorithm was accelerated with the ordered subsets (OS) procedure and compared to the FBP, OS-EM and conventional Bayesian reconstruction methods in terms of noise reduction, quantitative accuracy, edge preservation and visual quality. The results showed that the accelerated PH-MRP algorithm was very robust. It provided visually pleasing images with lower noise level than the FBP or OS-EM and with smaller bias and sharper edges than the conventional Bayesian methods.

  3. Limited angle tomographic breast imaging: A comparison of parallel beam and pinhole collimation

    International Nuclear Information System (INIS)

    Wessell, D.E.; Kadrmas, D.J.; Frey, E.C.

    1996-01-01

    Results from clinical trials have suggested no improvement in lesion detection with parallel hole SPECT scintimammography (SM) with Tc-99m over parallel hole planar SM. In this initial investigation, we have elucidated some of the unique requirements of SPECT SM. With these requirements in mind, we have begun to develop practical data acquisition and reconstruction strategies that can reduce image artifacts and improve image quality. In this paper we investigate limited angle orbits for both parallel hole and pinhole SPECT SM. Singular Value Decomposition (SVD) is used to analyze the artifacts associated with the limited angle orbits. Maximum likelihood expectation maximization (MLEM) reconstructions are then used to examine the effects of attenuation compensation on the quality of the reconstructed image. All simulations are performed using the 3D-MCAT breast phantom. The results of these simulation studies demonstrate that limited angle SPECT SM is feasible, that attenuation correction is needed for accurate reconstructions, and that pinhole SPECT SM may have an advantage over parallel hole SPECT SM in terms of improved image quality and reduced image artifacts

  4. Design and evaluation of two multi-pinhole collimators for brain SPECT.

    Science.gov (United States)

    Chen, Ling; Tsui, Benjamin M W; Mok, Greta S P

    2017-10-01

    SPECT is a powerful tool for diagnosing or staging brain diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD) but is limited by its inferior resolution and sensitivity. At the same time, pinhole SPECT provides superior resolution and detection efficiency trade-off as compared to the conventional parallel-hole collimator for imaging small field-of-view (FOV), which fits for the case of brain imaging. In this study, we propose to develop and evaluate two multi-pinhole (MPH) collimator designs to improve the imaging of cerebral blood flow and striatum. We set the target resolutions to be 12 and 8 mm, respectively, and the FOV at 200 mm which is large enough to cover the whole brain. The constraints for system optimization include maximum and minimum detector-to-center-of-FOV (CFOV) distances of 344 and 294 mm, respectively, and minimal radius-of-rotation (ROR) of 135 mm to accommodate patients' shoulder. According to the targeted FOV, resolutions, and constraints, we determined the pinhole number, ROR, focal length, aperture acceptance angle, and aperture diameter which maximized the system sensitivity. We then assessed the imaging performance of the proposed MPH and standard low-energy high-resolution (LEHR) collimators using analytical simulations of a digital NCAT brain phantom with 99m Tc-HMPAO/ 99m Tc-TRODAT-1 distributions; Monte Carlo simulations of a hot-rod phantom; and a Defrise phantom using GATE v6.1. Projections were generated over 360° and reconstructed using the 3D MPH/LEHR OS-EM methods with up to 720 updates. The normalized mean square error (NMSE) was calculated over the cerebral and striatal regions extracted from the reconstructed images for 99m Tc-HMPAO and 99m Tc-TRODAT-1 simulations, respectively, and average normalized standard deviation (NSD) based on 20 noise realizations was assessed on selected uniform 3D regions as the noise index. Visual assessment and image profiles were applied to the results of Monte Carlo

  5. Formation of nano-sized pinholes array in thin Ni film on MgO(100) substrate

    Energy Technology Data Exchange (ETDEWEB)

    Lin Chuan; Naramoto, Hiroshi; Xu Yonghua; Kitazawa, Sin-iti; Narumi, Kazumasa; Sakai, Seiji

    2003-10-22

    We have grown thin Ni films with various thicknesses on polished MgO(100) single crystal substrates in an e-gun evaporation system. The morphology of the as-deposited films was characterized with atomic force microscopy. Pinholes with average diameter of 5-10 nm are found in the film with thickness from 1 to 15 nm, and pinholes array was observed in the film 10 nm thick. The origin of such structure formation is discussed in terms of the elastic strain energy.

  6. Evaluation of parathyroid imaging methods with 99mTc-MIBI. The comparison of planar images obtained using a pinhole collimator and a parallel-hole collimator

    International Nuclear Information System (INIS)

    Fujii, Hirofumi; Iwasaki, Ryuichiro; Hashimoto, Jun; Nakamura, Kayoko; Kunieda, Etsuo; Sanmiya, Toshikazu; Kubo, Atsushi; Ogawa, Koichi; Inagaki, Kazutoshi

    1999-01-01

    Parathyroid scintigraphy with 99m Tc-MIBI was performed using two kinds of collimators, namely, a pinhole one and a parallel-hole one, to evaluate which one was more suitable for the detection of hyperfunctioning parathyroid lesions. In the studies using 99m Tc source, the pinhole collimator showed better efficiency and spatial resolution in the distance where the parathyroid scan are actually performed. In the phantom study, the nodular activities modeling parathyroid lesions were visualized better on the images obtained using the pinhole collimator. In clinical studies for 30 patients suspicious of hyperparathyroidism, hyperfunctioning parathyroid nodules were better detected when the pinhole collimator was used. In conclusion, the pinhole collimator was thought to be more suitable for parathyroid scintigraphy with 99m Tc-MIBI than the parallel-hole collimator. (author)

  7. Evaluation of parathyroid imaging methods with {sup 99m}Tc-MIBI. The comparison of planar images obtained using a pinhole collimator and a parallel-hole collimator

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Hirofumi; Iwasaki, Ryuichiro; Hashimoto, Jun; Nakamura, Kayoko; Kunieda, Etsuo; Sanmiya, Toshikazu; Kubo, Atsushi [Keio Univ., Tokyo (Japan). School of Medicine; Ogawa, Koichi; Inagaki, Kazutoshi

    1999-07-01

    Parathyroid scintigraphy with {sup 99m}Tc-MIBI was performed using two kinds of collimators, namely, a pinhole one and a parallel-hole one, to evaluate which one was more suitable for the detection of hyperfunctioning parathyroid lesions. In the studies using {sup 99m}Tc source, the pinhole collimator showed better efficiency and spatial resolution in the distance where the parathyroid scan are actually performed. In the phantom study, the nodular activities modeling parathyroid lesions were visualized better on the images obtained using the pinhole collimator. In clinical studies for 30 patients suspicious of hyperparathyroidism, hyperfunctioning parathyroid nodules were better detected when the pinhole collimator was used. In conclusion, the pinhole collimator was thought to be more suitable for parathyroid scintigraphy with {sup 99m}Tc-MIBI than the parallel-hole collimator. (author)

  8. Analytical, experimental, and Monte Carlo system response matrix for pinhole SPECT reconstruction

    International Nuclear Information System (INIS)

    Aguiar, Pablo; Pino, Francisco; Silva-Rodríguez, Jesús; Pavía, Javier; Ros, Doménec; Ruibal, Álvaro

    2014-01-01

    Purpose: To assess the performance of two approaches to the system response matrix (SRM) calculation in pinhole single photon emission computed tomography (SPECT) reconstruction. Methods: Evaluation was performed using experimental data from a low magnification pinhole SPECT system that consisted of a rotating flat detector with a monolithic scintillator crystal. The SRM was computed following two approaches, which were based on Monte Carlo simulations (MC-SRM) and analytical techniques in combination with an experimental characterization (AE-SRM). The spatial response of the system, obtained by using the two approaches, was compared with experimental data. The effect of the MC-SRM and AE-SRM approaches on the reconstructed image was assessed in terms of image contrast, signal-to-noise ratio, image quality, and spatial resolution. To this end, acquisitions were carried out using a hot cylinder phantom (consisting of five fillable rods with diameters of 5, 4, 3, 2, and 1 mm and a uniform cylindrical chamber) and a custom-made Derenzo phantom, with center-to-center distances between adjacent rods of 1.5, 2.0, and 3.0 mm. Results: Good agreement was found for the spatial response of the system between measured data and results derived from MC-SRM and AE-SRM. Only minor differences for point sources at distances smaller than the radius of rotation and large incidence angles were found. Assessment of the effect on the reconstructed image showed a similar contrast for both approaches, with values higher than 0.9 for rod diameters greater than 1 mm and higher than 0.8 for rod diameter of 1 mm. The comparison in terms of image quality showed that all rods in the different sections of a custom-made Derenzo phantom could be distinguished. The spatial resolution (FWHM) was 0.7 mm at iteration 100 using both approaches. The SNR was lower for reconstructed images using MC-SRM than for those reconstructed using AE-SRM, indicating that AE-SRM deals better with the

  9. Mechanistic study on black and grey spot growth in OLEDs performed on laser-ablated pinholes in the cathode

    NARCIS (Netherlands)

    Weijer, P. van de; Bouten, P.C.P.; Fledderus, H.; Janssen, R.R.; Winter, S.H.P.M. de; Akkerman, H.B.

    2017-01-01

    Local laser ablation of the cathode of OLEDs has been applied to create a population of pinholes of the same size. This enables the direct comparison at different conditions of black spots and grey spots in the emission of OLEDs as a result of water ingress into the device. We confirmed earlier

  10. Adrenal imaging with 131I-Adosterol (NCL-6-131I) by diverging and pinhole methods, 2

    International Nuclear Information System (INIS)

    Nakajo, Masayuki

    1982-01-01

    The analysis of the adrenal diverging and pinhole images with 131 I-Adosterol was made to establish adrenal imaging patterns, in 43 patients with various adrenal disorders, 4 with adrenal adjacent tumors and one with arrhenoblastoma of the ovary whose images were also included. From this analysis and review of literature, three principles (1. Accumulation in cortical tumors, 2. Relation to endogenous ACTH and 3. Nonaccumulation in noncortical tumors) and several additional factors to make various adrenal imaging patterns with 131 I-iodocholesterols could be induced. The accuracy of locating the adrenal tumor-bearing glands was 97% (28/29) with pinhole images and 70% (21/30) with diverging images in baseline conditions. Various adrenal high/low ratios could not be used as confidential indicators to locate the tumorbearing glands, especially in primary aldosteronism, although the left higher ratios on both views showed high discrepancy between normal and abnormal subjects. The ''Pinhole method'' is recommended as a simple technique of adrenal imaging, because it provides a high-resolution adrenal image which results in a high diagnostic value. A pinhole collimator is available in any institute which has a gamma camera. (author)

  11. Another look at volume self-calibration: calibration and self-calibration within a pinhole model of Scheimpflug cameras

    International Nuclear Information System (INIS)

    Cornic, Philippe; Le Besnerais, Guy; Champagnat, Frédéric; Illoul, Cédric; Cheminet, Adam; Le Sant, Yves; Leclaire, Benjamin

    2016-01-01

    We address calibration and self-calibration of tomographic PIV experiments within a pinhole model of cameras. A complete and explicit pinhole model of a camera equipped with a 2-tilt angles Scheimpflug adapter is presented. It is then used in a calibration procedure based on a freely moving calibration plate. While the resulting calibrations are accurate enough for Tomo-PIV, we confirm, through a simple experiment, that they are not stable in time, and illustrate how the pinhole framework can be used to provide a quantitative evaluation of geometrical drifts in the setup. We propose an original self-calibration method based on global optimization of the extrinsic parameters of the pinhole model. These methods are successfully applied to the tomographic PIV of an air jet experiment. An unexpected by-product of our work is to show that volume self-calibration induces a change in the world frame coordinates. Provided the calibration drift is small, as generally observed in PIV, the bias on the estimated velocity field is negligible but the absolute location cannot be accurately recovered using standard calibration data. (paper)

  12. Multi-dimensional diagnostics of high power ion beams by Arrayed Pinhole Camera System

    International Nuclear Information System (INIS)

    Yasuike, K.; Miyamoto, S.; Shirai, N.; Akiba, T.; Nakai, S.; Imasaki, K.; Yamanaka, C.

    1993-01-01

    The authors developed multi-dimensional beam diagnostics system (with spatially and time resolution). They used newly developed Arrayed Pinhole Camera (APC) for this diagnosis. The APC can get spatial distribution of divergence and flux density. They use two types of particle detectors in this study. The one is CR-39 can get time integrated images. The other one is gated Micro-Channel-Plate (MCP) with CCD camera. It enables time resolving diagnostics. The diagnostics systems have resolution better than 10mrad divergence, 0.5mm spatial resolution on the objects respectively. The time resolving system has 10ns time resolution. The experiments are performed on Reiden-IV and Reiden-SHVS induction linac. The authors get time integrated divergence distributions on Reiden-IV proton beam. They also get time resolved image on Reiden-SHVS

  13. Lasers and laser applications. Imaging implosion dynamics: The x-ray pinhole/streak camera

    International Nuclear Information System (INIS)

    Attwood, D.T.

    1976-01-01

    A Livermore-developed x-ray-sensitive streak camera was combined with a unique x-ray pinhole camera to make dynamic photographs of laser-irradiated fusion target implosions. These photographs show x radiation emitted from the imploding shell during its 100-ps implosion; they are the first continuous observations of an imploding laser-driven fusion capsule. The diagnostic system has a time resolution of 15 ps and a spatial resolution of about 6 μm. Results agree very well with those predicted by our LASNEX calculations, confirming that the essential physics are correctly described in the code and providing further confidence in the soundness of this approach to inertial confinement fusion

  14. Fabricating Pinhole-Free YSZ Sub-Microthin Films by Magnetron Sputtering for Micro-SOFCs

    Directory of Open Access Journals (Sweden)

    T. Hill

    2011-01-01

    Full Text Available Submicron thin yttria stabilized zirconia (YSZ films were prepared on a variety of substrates with different surface morphologies by magnetron sputtering followed by thermal oxidation. Pinholes were observed in the films deposited on nanoporous alumina substrates. Initial dense Y/Zr films developed nanocracks after thermal oxidation on smooth Si wafer substrates. At optimal sputtering and oxidation conditions, smooth and crack/pore-free films were achieved on Si wafer substrates. The thin YSZ films exhibited fully ionic conduction with ionic conductivities, and activation energy corroborated well with the values from commercial YSZ plates. The thin YSZ films can be utilized in Solid Oxide Fuel Cells (SOFCs for intermediate temperature operations.

  15. Imaging of intestinal lymphocyte homing by means of pinhole SPECT in a TNBS colitis mouse model

    International Nuclear Information System (INIS)

    Bennink, Roelof J.; Montfrans, Catherine van; Jonge, Wouter J. de; Bruin, Kora de; Deventer, Sander J. van; Velde, Anje A. te

    2004-01-01

    Background and aims: The increasing knowledge of the molecular basis of leukocyte trafficking results in the development of novel anti-inflammatory strategies for inflammatory bowel disease (IBD). For optimal evaluation of therapy efficacy, information about inflammatory activity in bowel segments or lymphocyte recirculation and kinetics in the follow-up of experimental treatment for IBD is needed. The aim of this study was to evaluate a non-invasive scintigraphic technique, able to assess lymphocyte trafficking in a trinitrobenzene sulfonic acid (TNBS) induced mouse colitis model of IBD. Methods: TNBS sensitized and non-sensitized murine total splenocytes were labeled in vitro with 111 In-oxine and injected into either control or TNBS colitis BALB/c mice. Biodistribution and specific radioactive uptake, representing transferred cells, were determined by serial dedicated animal planar scintigraphy and pinhole SPECT of the abdomen 4, 24 and 48h post injection of labeled cells. In addition, the severity of inflammation was. Results: Migration of 111 In labeled splenocytes to the colon increased in time and was maximal at 48h after administration. The highest specific radioactive uptake ratio in the colon after 48h was observed in mice with TNBS colitis that received TNBS sensitized lymphocytes. Histological scoring confirmed the presence of colitis in the TNBS treated groups. Conclusion: Homing of TNBS-sensitized lymphocytes can be assessed in vivo by means of dedicated animal pinhole SPECT. Generally, this technique enables serial measurement of specific cell trafficking with potential of in vivo evaluation of novel anti-inflammatory strategies in inflammatory bowel disease

  16. Pixelized measurement of {sup 99m}Tc-HDP micro particles formed in gamma correction phantom pinhole scan: A reference study

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Joo Young; Yoon, Do Kyun; Chung, Yong An [Catholic University of Korea, College of Medicine, Seoul (Korea, Republic of); Cheon, Gi Jeong; Lee, Yun Sang; Ha, Seunggyun [Radiopharmaceutical Science Laboratory, Dept. of Nuclear MedicineSeoul National University, College of Medicine, Seoul (Korea, Republic of); Bahk, Yong Whee [Dept. of Nuclear Medicine, Sung Ae General Hospital, Seoul (Korea, Republic of)

    2016-09-15

    Currently, traumatic bone diseases are diagnosed by assessing the micro {sup 99m}Tc-hydroxymethylene diphosphonate (HDP) uptake in injured trabeculae with ongoing osteoneogenesis demonstrated by gamma correction pinhole scan (GCPS). However, the mathematic size quantification of micro-uptake is not yet available. We designed and performed this phantom-based study to set up an in-vitro model of the mathematical calculation of micro-uptake by the pixelized measurement. The micro {sup 99m}Tc-HDP deposits used in this study were spontaneously formed both in a large standard flood and small house-made dish phantoms. The processing was as follows: first, phantoms were flooded with distilled water and {sup 99m}Tc-HDP was therein injected to induce micro {sup 99m}Tc-HDP deposition; second, the deposits were scanned using parallel-hole and pinhole collimator to generally survey {sup 99m}Tc-HDP deposition pattern; and third, the scans underwent gamma correction (GC) to discern individual deposits for size measurement. In original naïve scans, tracer distribution was simply nebulous in appearance and, hence, could not be measured. Impressively, however, GCPS could discern individual micro deposits so that they were calculated by pixelized measurement. Phantoms naturally formed micro {sup 99m}Tc-HDP deposits that are analogous to {sup 99m}Tc-HDP uptake on in-vivo bone scan. The smallest one we measured was 0.414 mm. Flooded phantoms and therein injected {sup 99m}Tc-HDP form nebulous micro {sup 99m}Tc-HDP deposits that are rendered discernible by GCPB and precisely calculable using pixelized measurement. This method can be used for precise quantitative and qualitative diagnosis of bone and joint diseases at the trabecular level.

  17. Radionuclide mass transfer rates from a pinhole in a waste container for an inventory-limited and a constant concentration source

    International Nuclear Information System (INIS)

    LeNeveu, D.M.

    1996-03-01

    Analytical solutions for transient and steady state diffusive mass transfer rates from a pinhole in a waste container are developed for constant concentration and inventory-limited source conditions. Mass transport in three media are considered, inside the pinhole (medium 2), outside the container (medium 3) and inside the container (medium 1). Simple equations are developed for radionuclide mass transfer rates from a pinhole. It is shown that the medium with the largest mass transfer resistance need only be considered to provide a conservative estimate of mass transfer rates. (author) 11 refs., 3 figs

  18. ORIENTATION ON STAKEHOLDERS’ OBJECTIVES AS A KEY COMPETENCE OF IMAGE FORMATION OF THE EDUCATIONAL INSTITUTIONS OF HIGHER EDUCATION (GERMAN EXPERIENCE

    Directory of Open Access Journals (Sweden)

    E. N. Kovaleva

    2015-01-01

    Full Text Available Summary. Creating relevant targets activities of marketing model of image formation of the educational organization of higher education is not possible without a systematic approach to understanding the purpose of the key stakeholder organizations that are not only state controls system (one of the stakeholders, but also a number of other, no less important: applicants, students, alumni, members of the business community. In Russia, the opinion of stakeholders in the organization of the learning process is not widely used in the practice of evaluation of educational institutions of higher education, with the exception of the activities implemented in some universities of quality management systems. The article explains the need to reorient the objectives and criteria for measuring the efficiency of the educational institutions of higher education in the target key stakeholder groups. The author has made a comparative analysis of the basic regulations of Russia and Germany in the field of higher education to establish the objectives of the universities and their orientation to target stakeholders. It revealed a possible mechanism for measuring the satisfaction of the stakeholders of the educational activities of the organization on the basis of benchmarking analysis of multi-dimensional ranking higher education programs in Germany. The activities of the state and the public in Germany shows that the estimate legitimate stakeholder groups can be used to assess the activity of educational institutions, the formation of a rational demand for educational services, improve the activities of universities and the formation of objective information field of competitive relations of universities. Focusing on the needs of the stakeholders may not be manifested hypothetical task of universities and law enshrined in the form of goals and objectives of universities imperative to correlate with national interests, the interests of the professional community as

  19. Theoretical and experimental study of image formation in scanning transmission electron microscopy

    International Nuclear Information System (INIS)

    Prunier epouse Mory, Claudie

    1985-01-01

    This thesis contains a theoretical and experimental study of image formation in a dedicated scanning transmission electron microscope (STEM). Using a detailed description of the different optical elements between the field emission source and the specimen, one calculates the shape and size of the primary probe of electrons impinging on the sample. This modelization enables to estimate the spatial resolution in the different imaging or microanalytical modes. The influence of the specimen and the role of the various detectors are taken into account to calculate the point spread function of the instrument in STEM imaging modes. An experimental study of the characteristic properties of phase contrast bright field micrographs and incoherent dark field ones is performed by comparison of digitally recorded images in similar conditions. Spatial resolution, contrast and signal/noise ratio are assessed by correlation methods, Fourier analysis and statistical considerations; one can deduce the optimum focusing conditions. Limits such as the point resolution on quasi-atomic metallic clusters are determined and an analysis of the capabilities of signal mixing concludes this work. Applications are offered in various domains such as the visualisation of small metallic particles, biomolecules and unstained biological sections. (author) [fr

  20. Analytical, experimental, and Monte Carlo system response matrix for pinhole SPECT reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, Pablo, E-mail: pablo.aguiar.fernandez@sergas.es [Fundación Ramón Domínguez, Medicina Nuclear, CHUS, Spain and Grupo de Imaxe Molecular, IDIS, Santiago de Compostela 15706 (Spain); Pino, Francisco [Unitat de Biofísica, Facultat de Medicina, Universitat de Barcelona, Spain and Servei de Física Médica i Protecció Radiológica, Institut Catalá d' Oncologia, Barcelona 08036 (Spain); Silva-Rodríguez, Jesús [Fundación Ramón Domínguez, Medicina Nuclear, CHUS, Santiago de Compostela 15706 (Spain); Pavía, Javier [Servei de Medicina Nuclear, Hospital Clínic, Barcelona (Spain); Institut d' Investigacions Biomèdiques August Pí i Sunyer (IDIBAPS) (Spain); CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona 08036 (Spain); Ros, Doménec [Unitat de Biofísica, Facultat de Medicina, Casanova 143 (Spain); Institut d' Investigacions Biomèdiques August Pí i Sunyer (IDIBAPS) (Spain); CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona 08036 (Spain); Ruibal, Álvaro [Servicio Medicina Nuclear, CHUS (Spain); Grupo de Imaxe Molecular, Facultade de Medicina (USC), IDIS, Santiago de Compostela 15706 (Spain); Fundación Tejerina, Madrid (Spain); and others

    2014-03-15

    Purpose: To assess the performance of two approaches to the system response matrix (SRM) calculation in pinhole single photon emission computed tomography (SPECT) reconstruction. Methods: Evaluation was performed using experimental data from a low magnification pinhole SPECT system that consisted of a rotating flat detector with a monolithic scintillator crystal. The SRM was computed following two approaches, which were based on Monte Carlo simulations (MC-SRM) and analytical techniques in combination with an experimental characterization (AE-SRM). The spatial response of the system, obtained by using the two approaches, was compared with experimental data. The effect of the MC-SRM and AE-SRM approaches on the reconstructed image was assessed in terms of image contrast, signal-to-noise ratio, image quality, and spatial resolution. To this end, acquisitions were carried out using a hot cylinder phantom (consisting of five fillable rods with diameters of 5, 4, 3, 2, and 1 mm and a uniform cylindrical chamber) and a custom-made Derenzo phantom, with center-to-center distances between adjacent rods of 1.5, 2.0, and 3.0 mm. Results: Good agreement was found for the spatial response of the system between measured data and results derived from MC-SRM and AE-SRM. Only minor differences for point sources at distances smaller than the radius of rotation and large incidence angles were found. Assessment of the effect on the reconstructed image showed a similar contrast for both approaches, with values higher than 0.9 for rod diameters greater than 1 mm and higher than 0.8 for rod diameter of 1 mm. The comparison in terms of image quality showed that all rods in the different sections of a custom-made Derenzo phantom could be distinguished. The spatial resolution (FWHM) was 0.7 mm at iteration 100 using both approaches. The SNR was lower for reconstructed images using MC-SRM than for those reconstructed using AE-SRM, indicating that AE-SRM deals better with the

  1. Tomographic and analog 3-D simulations using NORA. [Non-Overlapping Redundant Image Array formed by multiple pinholes

    Science.gov (United States)

    Yin, L. I.; Trombka, J. I.; Bielefeld, M. J.; Seltzer, S. M.

    1984-01-01

    The results of two computer simulations demonstrate the feasibility of using the nonoverlapping redundant array (NORA) to form three-dimensional images of objects with X-rays. Pinholes admit the X-rays to nonoverlapping points on a detector. The object is reconstructed in the analog mode by optical correlation and in the digital mode by tomographic computations. Trials were run with a stick-figure pyramid and extended objects with out-of-focus backgrounds. Substitution of spherical optical lenses for the pinholes increased the light transmission sufficiently that objects could be easily viewed in a dark room. Out-of-focus aberrations in tomographic reconstruction could be eliminated using Chang's (1976) algorithm.

  2. Single order soft X-ray diffraction with quasi-random radius pinhole array spectroscopic photon sieves

    International Nuclear Information System (INIS)

    Zhang Qiang-Qiang; Wei Lai; Yang Zu-Hua; Qian Feng; Fan Quan-Ping; Zhang Bo; Gu Yu-Qiu; Cao Lei-Feng

    2014-01-01

    A novel single order diffraction grating in the soft X-ray region, called quasi-random radius pinhole array spectroscopic photon sieves (QRSPS), is proposed in this paper. This new grating is composed of pinholes on a substrate, whose radii are quasi-random, while their centers are regular. Analysis proves that its transmittance function across the grating bar is similar to that of sinusoidal transmission gratings. Simulation results show that the QRSPS can suppress higher-order diffraction effectively. And the QRSPS would still retain its characteristic of single order diffraction when we take the effect of X-ray penetration into account. These properties indicate that the QRSPS can be used in the soft X-ray spectra measurement. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  3. The feasibility study on 3-dimensional fluorescent x-ray computed tomography using the pinhole effect for biomedical applications.

    Science.gov (United States)

    Sunaguchi, Naoki; Yuasa, Tetsuya; Hyodo, Kazuyuki; Zeniya, Tsutomu

    2013-01-01

    We propose a 3-dimensional fluorescent x-ray computed tomography (CT) pinhole collimator, aimed at providing molecular imaging with quantifiable measures and sub-millimeter spatial resolution. In this study, we demonstrate the feasibility of this concept and investigate imaging properties such as spatial resolution, contrast resolution and quantifiable measures, by imaging physical phantoms using a preliminary imaging system developed with monochromatic synchrotron x rays constructed at the BLNE-7A experimental line at KEK, Japan.

  4. Obtaining absolute spatial flux measurements with a time-resolved pinhole camera

    International Nuclear Information System (INIS)

    Baker, K.L.; Porter, J.L.; Ruggles, L.E.; Fehl, D.L.; Chandler, G.A.; Vargas, M.; Mix, L.P.; Simpson, W.W.; Deeney, C.; Chrien, R.E.; Idzorek, G.C.

    1999-01-01

    A technique is described to determine the spatial x-ray flux emitted from a hohlraum wall and subsequently transmitted through a diagnostic hole. This technique uses x-ray diodes, bolometers, and a time-resolved pinhole camera to determine the spatial flux of x rays emitted through a hohlraum close-quote s diagnostic hole. The primary motivation for this analysis was the relatively long duration, nearly 100 ns, of the x-ray drive present in z-pinch driven hohlraums. This radiation causes plasma to ablate from the hohlraum walls surrounding the diagnostic hole and results in a partial obscuration that reduces the effective area over which diagnostics view the radiation. The effective change in area leads to an underestimation of the wall temperature when nonimaging diagnostics such as x-ray diodes and bolometers are used to determine power and later to infer a wall temperature. An analysis similar to the one described below is then necessary to understand the radiation environment present in x-ray driven hohlraums when these diagnostics are used and hole closure is important. copyright 1999 American Institute of Physics

  5. GATE simulation of a new design of pinhole SPECT system for small animal brain imaging

    International Nuclear Information System (INIS)

    Ozsahin, D. Uzun; Bläckberg, L.; Fakhri, G. El; Sabet, H.

    2017-01-01

    Small animal SPECT imaging has gained an increased interest over the past decade since it is an excellent tool for developing new drugs and tracers. Therefore, there is a huge effort on the development of cost-effective SPECT detectors with high capabilities. The aim of this study is to simulate the performance characteristics of new designs for a cost effective, stationary SPECT system dedicated to small animal imaging with a focus on mice brain. The conceptual design of this SPECT system platform, Stationary Small Animal SSA-SPECT, is to use many pixelated CsI:TI detector modules with 0.4 mm × 0.4 mm pixels in order to achieve excellent intrinsic detector resolution where each module is backed by a single pinhole collimator with 0.3 mm hole diameter. In this work, we present the simulation results of four variations of the SSA-SPECT platform where the number of detector modules and FOV size is varied while keeping the detector size and collimator hole size constant. Using the NEMA NU-4 protocol, we performed spatial resolution, sensitivity, image quality simulations followed by a Derenzo-like phantom evaluation. The results suggest that all four SSA-SPECT systems can provide better than 0.063% system sensitivity and < 1.5 mm FWHM spatial resolution without resolution recovery or other correction techniques. Specifically, SSA-SPECT-1 showed a system sensitivity of 0.09% in combination with 1.1 mm FWHM spatial resolution.

  6. Estimation of signal intensity for online measurement X-ray pinhole camera

    International Nuclear Information System (INIS)

    Dong Jianjun; Liu Shenye; Yang Guohong; Yu Yanning

    2009-01-01

    The signal intensity was estimated for on-line measurement X-ray pinhole camera with CCD as measurement equipment. The X-ray signal intensity counts after the attenuation of thickness-varied Be filters and different material flat mirrors respectively were estimated using the energy spectrum of certain laser prototype and the quantum efficiency curve of PI-SX1300 CCD camera. The calculated results indicate that Be filters no thicker than 200 μm can only reduce signal intensity by one order of magnitude, and so can Au flat mirror with 3 degree incident angle, Ni, C and Si flat mirrors with 5 degree incident angle,but the signal intensity counts for both attenuation methods are beyond the saturation counts of the CCD camera. We also calculated the attenuation of signal intensity for different thickness Be filters combined with flat mirrors, indicates that the combination of Be filters with the thickness between 20 and 40 μm and Au flat mirror with 3 degree incident angle or Ni flat mirror with 5 degree incident angle is a good choice for the attenuation of signal intensity. (authors)

  7. The performance of a hybrid analytical-Monte Carlo system response matrix in pinhole SPECT reconstruction

    International Nuclear Information System (INIS)

    El Bitar, Z; Pino, F; Candela, C; Ros, D; Pavía, J; Rannou, F R; Ruibal, A; Aguiar, P

    2014-01-01

    It is well-known that in pinhole SPECT (single-photon-emission computed tomography), iterative reconstruction methods including accurate estimations of the system response matrix can lead to submillimeter spatial resolution. There are two different methods for obtaining the system response matrix: those that model the system analytically using an approach including an experimental characterization of the detector response, and those that make use of Monte Carlo simulations. Methods based on analytical approaches are faster and handle the statistical noise better than those based on Monte Carlo simulations, but they require tedious experimental measurements of the detector response. One suggested approach for avoiding an experimental characterization, circumventing the problem of statistical noise introduced by Monte Carlo simulations, is to perform an analytical computation of the system response matrix combined with a Monte Carlo characterization of the detector response. Our findings showed that this approach can achieve high spatial resolution similar to that obtained when the system response matrix computation includes an experimental characterization. Furthermore, we have shown that using simulated detector responses has the advantage of yielding a precise estimate of the shift between the point of entry of the photon beam into the detector and the point of interaction inside the detector. Considering this, it was possible to slightly improve the spatial resolution in the edge of the field of view. (paper)

  8. Novel energy resolving x-ray pinhole camera on Alcator C-Moda)

    Science.gov (United States)

    Pablant, N. A.; Delgado-Aparicio, L.; Bitter, M.; Brandstetter, S.; Eikenberry, E.; Ellis, R.; Hill, K. W.; Hofer, P.; Schneebeli, M.

    2012-10-01

    A new energy resolving x-ray pinhole camera has been recently installed on Alcator C-Mod. This diagnostic is capable of 1D or 2D imaging with a spatial resolution of ≈1 cm, an energy resolution of ≈1 keV in the range of 3.5-15 keV and a maximum time resolution of 5 ms. A novel use of a Pilatus 2 hybrid-pixel x-ray detector [P. Kraft et al., J. Synchrotron Rad. 16, 368 (2009), 10.1107/S0909049509009911] is employed in which the lower energy threshold of individual pixels is adjusted, allowing regions of a single detector to be sensitive to different x-ray energy ranges. Development of this new detector calibration technique was done as a collaboration between PPPL and Dectris Ltd. The calibration procedure is described, and the energy resolution of the detector is characterized. Initial data from this installation on Alcator C-Mod is presented. This diagnostic provides line-integrated measurements of impurity emission which can be used to determine impurity concentrations as well as the electron energy distribution.

  9. Experimental task-based optimization of a four-camera variable-pinhole small-animal SPECT system

    Science.gov (United States)

    Hesterman, Jacob Y.; Kupinski, Matthew A.; Furenlid, Lars R.; Wilson, Donald W.

    2005-04-01

    We have previously utilized lumpy object models and simulated imaging systems in conjunction with the ideal observer to compute figures of merit for hardware optimization. In this paper, we describe the development of methods and phantoms necessary to validate or experimentally carry out these optimizations. Our study was conducted on a four-camera small-animal SPECT system that employs interchangeable pinhole plates to operate under a variety of pinhole configurations and magnifications (representing optimizable system parameters). We developed a small-animal phantom capable of producing random backgrounds for each image sequence. The task chosen for the study was the detection of a 2mm diameter sphere within the phantom-generated random background. A total of 138 projection images were used, half of which included the signal. As our observer, we employed the channelized Hotelling observer (CHO) with Laguerre-Gauss channels. The signal-to-noise (SNR) of this observer was used to compare different system configurations. Results indicate agreement between experimental and simulated data with higher detectability rates found for multiple-camera, multiple-pinhole, and high-magnification systems, although it was found that mixtures of magnifications often outperform systems employing a single magnification. This work will serve as a basis for future studies pertaining to system hardware optimization.

  10. Preliminary study on X-ray fluorescence computed tomography imaging of gold nanoparticles: Acceleration of data acquisition by multiple pinholes scheme

    Science.gov (United States)

    Sasaya, Tenta; Sunaguchi, Naoki; Seo, Seung-Jum; Hyodo, Kazuyuki; Zeniya, Tsutomu; Kim, Jong-Ki; Yuasa, Tetsuya

    2018-04-01

    Gold nanoparticles (GNPs) have recently attracted attention in nanomedicine as novel contrast agents for cancer imaging. A decisive tomographic imaging technique has not yet been established to depict the 3-D distribution of GNPs in an object. An imaging technique known as pinhole-based X-ray fluorescence computed tomography (XFCT) is a promising method that can be used to reconstruct the distribution of GNPs from the X-ray fluorescence emitted by GNPs. We address the acceleration of data acquisition in pinhole-based XFCT for preclinical use using a multiple pinhole scheme. In this scheme, multiple projections are simultaneously acquired through a multi-pinhole collimator with a 2-D detector and full-field volumetric beam to enhance the signal-to-noise ratio of the projections; this enables fast data acquisition. To demonstrate the efficacy of this method, we performed an imaging experiment using a physical phantom with an actual multi-pinhole XFCT system that was constructed using the beamline AR-NE7A at KEK. The preliminary study showed that the multi-pinhole XFCT achieved a data acquisition time of 20 min at a theoretical detection limit of approximately 0.1 Au mg/ml and at a spatial resolution of 0.4 mm.

  11. Longitudinal in vivo evaluation of bone regeneration by combined measurement of multi-pinhole SPECT and micro-CT for tissue engineering

    Science.gov (United States)

    Lienemann, Philipp S.; Metzger, Stéphanie; Kiveliö, Anna-Sofia; Blanc, Alain; Papageorgiou, Panagiota; Astolfo, Alberto; Pinzer, Bernd R.; Cinelli, Paolo; Weber, Franz E.; Schibli, Roger; Béhé, Martin; Ehrbar, Martin

    2015-05-01

    Over the last decades, great strides were made in the development of novel implants for the treatment of bone defects. The increasing versatility and complexity of these implant designs request for concurrent advances in means to assess in vivo the course of induced bone formation in preclinical models. Since its discovery, micro-computed tomography (micro-CT) has excelled as powerful high-resolution technique for non-invasive assessment of newly formed bone tissue. However, micro-CT fails to provide spatiotemporal information on biological processes ongoing during bone regeneration. Conversely, due to the versatile applicability and cost-effectiveness, single photon emission computed tomography (SPECT) would be an ideal technique for assessing such biological processes with high sensitivity and for nuclear imaging comparably high resolution (designed poly(ethylene glycol)-based hydrogels that release bone morphogenetic protein to guide the healing of critical sized calvarial bone defects. By combined in vivo longitudinal multi-pinhole SPECT and micro-CT evaluations we determine the spatiotemporal course of bone formation and remodeling within this synthetic hydrogel implant. End point evaluations by high resolution micro-CT and histological evaluation confirm the value of this approach to follow and optimize bone-inducing biomaterials.

  12. A comparative study on PET and SPECT image formation systems for a proper scanner choice in a considered PET center

    International Nuclear Information System (INIS)

    Santos, G.R. dos; Oliveira, A. de; Oliveira, C.L. de

    2001-01-01

    Full text: In the last twenty years, the conjunction of technology and research had provided exceptional conditions for improvements on the quality of life, specially on nuclear medicine. In this area, the developed technology is being applied, making available better diagnoses and therapy to a variety of diseases. Since then the short-lived radionuclides were available only in the large physics research centers. The increasing clinical applications have led to the rapid rise in the number of compact cyclotrons throughout the world. All medical cyclotrons currently are suitable for sustaining programs for PET research and clinical application. To date, up to 122 medical cyclotrons have been established worldwide, and Brazil is about to install a new dedicated cyclotron (RDS111 from CTI), to its first PET Center, in Rio de Janeiro. Also the number of scanners worldwide has increased, mainly those based on the positrons emission and annihilation. The better result gotten in the final contrast of the object imposes a comparative study and analysis of the image formation process, either in a system based on a Single Photon Emission Computerized Tomography (SPECT), as well as on Positron Emission Tomography (PET.) This comparative study should at least follow same increasing rates of the new devices with technological advances. That kind of study can be helpful on the decision of what type of scan should be the proper one, to a PET Center, on a specific region. Obviously, many other parameters are involved in that decision, and this discussion and analyses are the main subject of the present work. The objective is to make available a realistic comparative scenario. Many of the new devices have been introduced making progresses. As an example, in the new PET scanners, the reduction of examination time, and the remarkable improvement on the diagnoses based on images. As a consequence, we have a broadening on application, better performance, and making possible the

  13. Trends in medical image processing

    International Nuclear Information System (INIS)

    Robilotta, C.C.

    1987-01-01

    The function of medical image processing is analysed, mentioning the developments, the physical agents, and the main categories, as conection of distortion in image formation, detectability increase, parameters quantification, etc. (C.G.C.) [pt

  14. Reconstruction of 2D x-ray radiographs at the National Ignition Facility using pinhole tomography (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Field, J. E., E-mail: field9@llnl.gov; Rygg, J. R.; Barrios, M. A.; Benedetti, L. R.; Döppner, T.; Izumi, N.; Jones, O.; Khan, S. F.; Ma, T.; Nagel, S. R.; Pak, A.; Tommasini, R.; Bradley, D. K.; Town, R. P. J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2014-11-15

    Two-dimensional radiographs of imploding fusion capsules are obtained at the National Ignition Facility by projection through a pinhole array onto a time-gated framing camera. Parallax among images in the image array makes it possible to distinguish contributions from the capsule and from the backlighter, permitting correction of backlighter non-uniformities within the capsule radiograph. Furthermore, precise determination of the imaging system geometry and implosion velocity enables combination of multiple images to reduce signal-to-noise and discover new capsule features.

  15. Dynamic molecular imaging of cardiac innervation using a dual head pinhole SPECT system

    International Nuclear Information System (INIS)

    Hu, Jicun; Boutchko, Rostyslav; Sitek, Arkadiusz; Reutter, BryanW.; Huesman, Ronald H.; Gullberg, Grant T.

    2008-01-01

    Typically 123I-MIBG is used for the study of innervation and function of the sympathetic nervous system in heart failure. The protocol involves two studies: first a planar or SPECT scan is performed to measure initial uptake of the tracer, followed some 3-4 hours later by another study measuring the wash-out of the tracer from the heart. A fast wash-out is indicative of a compromised heart. In this work, a dual head pinhole SPECT system was used for imaging the distribution and kinetics of 123I-MIBG in the myocardium of spontaneous hypertensive rats (SHR) and normotensive Wistar Kyoto (WKY) rats. The system geometry was calibrated based on a nonlinear point projection fitting method using a three-point source phantom. The angle variation effect of the parameters was modeled with a sinusoidal function. A dynamic acquisition was performed by injecting 123I-MIBG into rats immediately after starting the data acquisition. The detectors rotated continuously performing a 360o data acquisition every 90 seconds. We applied the factor analysis (FA)method and region of interest (ROI) sampling method to obtain time activity curves (TACs)in the blood pool and myocardium and then applied two-compartment modeling to estimate the kinetic parameters. Since the initial injection bolus is too fast for obtaining a consistent tomographic data set in the first few minutes of the study, we applied the FA method directly to projections during the first rotation. Then the time active curves for blood and myocardial tissue were obtained from ROI sampling. The method was applied to determine if there were differences in the kinetics between SHR and WKY rats and requires less time by replacing the delayed scan at 3-4 hours after injection with a dynamic acquisition over 90 to 120 minutes. The results of a faster washout and a smaller distribution volume of 123I-MIBG near the end of life in the SHR model of hypertrophic cardiomyopthy may be indicative of a failing heart in late stages of heart

  16. The Strength of Lecturer Interpersonal Communication in The Image Formation of Marketing Communication Students, Bina Nusantara University

    Directory of Open Access Journals (Sweden)

    Dina Sekar Vusparatih

    2016-07-01

    Full Text Available The good relations would have a direct impact on the impression created in the students’ perception. The existence of a positive image of the lecturers would certainly go hand in hand with the creation of a positive image for the majors and the university eventually. This article used case study with qualitative method. The interview was the main tool of data collection. Researchers chosea few students who are still studying during the research but have been studying for few years (3 years or 6 semesters as the resources/interviewee. It finds that indirectly style and interpersonal communication skills of lecturers can affect image formation majors and university. 

  17. A numerical analysis of the Born approximation for image formation modeling of differential interference contrast microscopy for human embryos

    Science.gov (United States)

    Trattner, Sigal; Feigin, Micha; Greenspan, Hayit; Sochen, Nir

    2008-03-01

    The differential interference contrast (DIC) microscope is commonly used for the visualization of live biological specimens. It enables the view of the transparent specimens while preserving their viability, being a non-invasive modality. Fertility clinics often use the DIC microscope for evaluation of human embryos quality. Towards quantification and reconstruction of the visualized specimens, an image formation model for DIC imaging is sought and the interaction of light waves with biological matter is examined. In many image formation models the light-matter interaction is expressed via the first Born approximation. The validity region of this approximation is defined in a theoretical bound which limits its use to very small specimens with low dielectric contrast. In this work the Born approximation is investigated via the Helmholtz equation, which describes the interaction between the specimen and light. A solution on the lens field is derived using the Gaussian Legendre quadrature formulation. This numerical scheme is considered both accurate and efficient and has shortened significantly the computation time as compared to integration methods that required a great amount of sampling for satisfying the Whittaker - Shannon sampling theorem. By comparing the numerical results with the theoretical values it is shown that the theoretical bound is not directly relevant to microscopic imaging and is far too limiting. The numerical exhaustive experiments show that the Born approximation is inappropriate for modeling the visualization of thick human embryos.

  18. Improved image quality in pinhole SPECT by accurate modeling of the point spread function in low magnification systems

    International Nuclear Information System (INIS)

    Pino, Francisco; Roé, Nuria; Aguiar, Pablo; Falcon, Carles; Ros, Domènec; Pavía, Javier

    2015-01-01

    Purpose: Single photon emission computed tomography (SPECT) has become an important noninvasive imaging technique in small-animal research. Due to the high resolution required in small-animal SPECT systems, the spatially variant system response needs to be included in the reconstruction algorithm. Accurate modeling of the system response should result in a major improvement in the quality of reconstructed images. The aim of this study was to quantitatively assess the impact that an accurate modeling of spatially variant collimator/detector response has on image-quality parameters, using a low magnification SPECT system equipped with a pinhole collimator and a small gamma camera. Methods: Three methods were used to model the point spread function (PSF). For the first, only the geometrical pinhole aperture was included in the PSF. For the second, the septal penetration through the pinhole collimator was added. In the third method, the measured intrinsic detector response was incorporated. Tomographic spatial resolution was evaluated and contrast, recovery coefficients, contrast-to-noise ratio, and noise were quantified using a custom-built NEMA NU 4–2008 image-quality phantom. Results: A high correlation was found between the experimental data corresponding to intrinsic detector response and the fitted values obtained by means of an asymmetric Gaussian distribution. For all PSF models, resolution improved as the distance from the point source to the center of the field of view increased and when the acquisition radius diminished. An improvement of resolution was observed after a minimum of five iterations when the PSF modeling included more corrections. Contrast, recovery coefficients, and contrast-to-noise ratio were better for the same level of noise in the image when more accurate models were included. Ring-type artifacts were observed when the number of iterations exceeded 12. Conclusions: Accurate modeling of the PSF improves resolution, contrast, and recovery

  19. Improved image quality in pinhole SPECT by accurate modeling of the point spread function in low magnification systems

    Energy Technology Data Exchange (ETDEWEB)

    Pino, Francisco [Unitat de Biofísica, Facultat de Medicina, Universitat de Barcelona, Barcelona 08036, Spain and Servei de Física Mèdica i Protecció Radiològica, Institut Català d’Oncologia, L’Hospitalet de Llobregat 08907 (Spain); Roé, Nuria [Unitat de Biofísica, Facultat de Medicina, Universitat de Barcelona, Barcelona 08036 (Spain); Aguiar, Pablo, E-mail: pablo.aguiar.fernandez@sergas.es [Fundación Ramón Domínguez, Complexo Hospitalario Universitario de Santiago de Compostela 15706, Spain and Grupo de Imagen Molecular, Instituto de Investigacións Sanitarias de Santiago de Compostela (IDIS), Galicia 15782 (Spain); Falcon, Carles; Ros, Domènec [Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona 08036, Spain and CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona 08036 (Spain); Pavía, Javier [Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona 080836 (Spain); CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona 08036 (Spain); and Servei de Medicina Nuclear, Hospital Clínic, Barcelona 08036 (Spain)

    2015-02-15

    Purpose: Single photon emission computed tomography (SPECT) has become an important noninvasive imaging technique in small-animal research. Due to the high resolution required in small-animal SPECT systems, the spatially variant system response needs to be included in the reconstruction algorithm. Accurate modeling of the system response should result in a major improvement in the quality of reconstructed images. The aim of this study was to quantitatively assess the impact that an accurate modeling of spatially variant collimator/detector response has on image-quality parameters, using a low magnification SPECT system equipped with a pinhole collimator and a small gamma camera. Methods: Three methods were used to model the point spread function (PSF). For the first, only the geometrical pinhole aperture was included in the PSF. For the second, the septal penetration through the pinhole collimator was added. In the third method, the measured intrinsic detector response was incorporated. Tomographic spatial resolution was evaluated and contrast, recovery coefficients, contrast-to-noise ratio, and noise were quantified using a custom-built NEMA NU 4–2008 image-quality phantom. Results: A high correlation was found between the experimental data corresponding to intrinsic detector response and the fitted values obtained by means of an asymmetric Gaussian distribution. For all PSF models, resolution improved as the distance from the point source to the center of the field of view increased and when the acquisition radius diminished. An improvement of resolution was observed after a minimum of five iterations when the PSF modeling included more corrections. Contrast, recovery coefficients, and contrast-to-noise ratio were better for the same level of noise in the image when more accurate models were included. Ring-type artifacts were observed when the number of iterations exceeded 12. Conclusions: Accurate modeling of the PSF improves resolution, contrast, and recovery

  20. A study of the multiple pinhole coded aperture and the application of the minicomputer in image decoding

    International Nuclear Information System (INIS)

    Hasegawa, Takeo; Hashiba, Hiroshi; Akagi, Kiyoshi; Kobayashi, Akitoshi; Matsuda, Magoichi

    1979-01-01

    Research has been done on optically reconstructed imaging employing the Multiple Pinhole Coded Aperture (hereafter abbreviated as MPCA) in radioisotope tomographic imaging. However, problems remain in the optically reconstructed image method. Therefore, we employed a minicomputer (hereafter abbreviated as CPU) and developed the software for decoding and managing the radioisotope tomographic image. Combining the MPCA and the CPU system, we were able to decode and manage the radioisotope tomographic image. 1) In comparison to the optically decoded MPCA image, various input commands are possibly in the CPU method according to the dialogue between the CPU and the on line typewriter. In addition to this, decoded tomographic images of unrestricted depth are readily attainable. 2) In the CPU method noise elimination and other aspects of image management can be easily performed. (author)

  1. Simultaneous usage of pinhole and penumbral apertures for imaging small scale neutron sources from inertial confinement fusion experiments.

    Science.gov (United States)

    Guler, N; Volegov, P; Danly, C R; Grim, G P; Merrill, F E; Wilde, C H

    2012-10-01

    Inertial confinement fusion experiments at the National Ignition Facility are designed to understand the basic principles of creating self-sustaining fusion reactions by laser driven compression of deuterium-tritium (DT) filled cryogenic plastic capsules. The neutron imaging diagnostic provides information on the distribution of the central fusion reaction region and the surrounding DT fuel by observing neutron images in two different energy bands for primary (13-17 MeV) and down-scattered (6-12 MeV) neutrons. From this, the final shape and size of the compressed capsule can be estimated and the symmetry of the compression can be inferred. These experiments provide small sources with high yield neutron flux. An aperture design that includes an array of pinholes and penumbral apertures has provided the opportunity to image the same source with two different techniques. This allows for an evaluation of these different aperture designs and reconstruction algorithms.

  2. EXPERIMENTAL AND MONTE CARLO INVESTIGATIONS OF BCF-12 SMALL‑AREA PLASTIC SCINTILLATION DETECTORS FOR NEUTRON PINHOLE CAMERA.

    Science.gov (United States)

    Bielecki, J; Drozdowicz, K; Dworak, D; Igielski, A; Janik, W; Kulinska, A; Marciniak, L; Scholz, M; Turzanski, M; Wiacek, U; Woznicka, U; Wójcik-Gargula, A

    2017-12-11

    Plastic organic scintillators such as the blue-emitting BCF-12 are versatile and inexpensive tools. Recently, BCF-12 scintillators have been foreseen for investigation of the spatial distribution of neutrons emitted from dense magnetized plasma. For this purpose, small-area (5 mm × 5 mm) detectors based on BCF-12 scintillation rods and Hamamatsu photomultiplier tubes were designed and constructed at the Institute of Nuclear Physics. They will be located inside the neutron pinhole camera of the PF-24 plasma focus device. Two different geometrical layouts and approaches to the construction of the scintillation element were tested. The aim of this work was to determine the efficiency of the detectors. For this purpose, the experimental investigations using a neutron generator and a Pu-Be source were combined with Monte Carlo computations using the Geant4 code. © The Author(s) 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Imaging of striatal dopamine transporters in rat brain with single pinhole SPECT and co-aligned MRI is highly reproducible

    International Nuclear Information System (INIS)

    Booij, Jan; Bruin, Kora de; Win, Maartje M.L. de; Lavini, Cristina Mphil; Heeten, Gerard J. den; Habraken, Jan

    2003-01-01

    A recently developed pinhole high-resolution SPECT system was used to measure striatal to non-specific binding ratios in rats (n = 9), after injection of the dopamine transporter ligand 123 I-FP-CIT, and to assess its test/retest reproducibility. For co-alignment purposes, the rat brain was imaged on a 1.5 Tesla clinical MRI scanner using a specially developed surface coil. The SPECT images showed clear striatal uptake. On the MR images, cerebral and extra-cerebral structures could be easily delineated. The mean striatal to non-specific [ 123 I]FP-CIT binding ratios of the test/retest studies were 1.7 ± 0.2 and 1.6 ± 0.2, respectively. The test/retest variability was approximately 9%. We conclude that the assessment of striatal [ 123 I]FP-CIT binding ratios in rats is highly reproducible

  4. Adrenal imaging with 131I-adosterol (NCL-6-131I) by diverging and pinhole methods, 1

    International Nuclear Information System (INIS)

    Nakajo, Masayuki

    1981-01-01

    The adrenal diverging and pinhole images with 131 I-Adosterol in 80 subjects with no evidence of adrenal diseases were analyzed to establish the normal adrenal imaging patterns. The results obtained from the analysis of the diverging images were as follows: 1) The right gland was located higher than the left in 69% of the subjects and in 30% both adrenals were located at the same height. In only one subject, the left adrenal was slightly higher than the right. 2) On the posterior view, the right higher asymmetrical uptake was observed in most subjects (62.5%), whereas the symmetrical uptake was most frequently (69%) seen on the anterior view. This discrepancy could be explained by differences in depth, photon attenuation and hepatic overlapping radioactivity between both glands. 3) The adrenal high/low ratio on both views, semiquantitative comparison between both adrenal radioactivities, showed a higher deviation in the right higher group (mean; 1.37, range; 1.01 - 3.15) than in the left higher one, however, its deviation was small (mean; 1.14, range; 1.01 - 1.41). The high deviation values were due to the low uptake of the left glands. The results obtained from the analysis of the pinhole images were as follows: 1) Although the scintigraphic morphology differed essentially between both glands, the left glands were basically divided into oval (64%), triangular (25%), and round (11%) types, whereas the right glands were divided into triangular (64%), oval (25%) and round or sickle (11%) types. 2) The inner radioactive distributions of both glands were characteristic respectively. In 74% of the subjects, the left gland showed higher radioactivity in its upper and/or medial portion, and the radioactivity of the right was higher in its midportion and decreased toward its peripheral region in 76%. According to these results, the important points on interpretation of the adrenal images were discussed. (author)

  5. Estimation of the Contribution of Primary and Secondary Radiation to a Pinhole Volume from a Water Phantom

    International Nuclear Information System (INIS)

    Gamage, Kelum-A.-A.; Joyce, Malcolm-J.; Taylor, Graeme-C.

    2013-06-01

    The imaging of mixed radiation fields with organic liquid scintillation detectors became feasible as a result of recent advances in digital pulse-shape discrimination methods. The use of a liquid scintillator has significant benefits over other techniques for imaging radiation environments as the acquired data can be analysed to provide separate information about the gamma and neutron emissions from a source (or sources) in a single scan in near real-time. This method has significant potential for the location of radioactive sources in radiation environments in the nuclear industry, nuclear decommissioning and homeland security applications. A further application of the mixed-field imaging system would be to detect, locate and study the secondary radiation produced during proton therapy. Proton therapy uses a particle accelerator to target a tumour within the body with a beam of protons. The presence of materials in the beam path as well as the patient, leads to the production of secondary particles such as neutrons and gamma rays. In this paper the contribution of scattered and secondary radiation from a water phantom to a pinhole volume, as a result of three neutron sources and two gamma sources, is separately estimated using the PTRAC particle tracking option available in MCNP. A spherical tally volume, 2 cm in diameter, was placed equidistantly from a radioactive source and 30*30*15 cm 3 water phantom. Monte Carlo simulations have been carried out to investigate the level of primary and secondary radiation contributing to the pinhole volume from interactions in the phantom. This can be used as a simple method to visualise the results expected from the mixed-field imaging system. The results have shown that the percentage of neutrons reflected from the phantom with energies above 1 MeV goes up with mean energy of the source. (authors)

  6. Novel use of gamma correction for precise {sup 99m}Tc-HDP pinhole bone scan diagnosis and classification of knee occult fractures

    Energy Technology Data Exchange (ETDEWEB)

    Bahk, Yong-Whee [Sung Ae General Hospital, Department of Nuclear Medicine, Seoul (Korea); Jeon, Ho-Seung [Sung Ae General Hospital, Department of Orthopedic Surgery, Seoul (Korea); Kim, Jang Min [Sung Ae General Hospital, Department of Radiology, Seoul (Korea); Park, Jung Mee; Kim, Sung-Hoon; Chung, Soo-Kyo [The Catholic University of Korea, Department of Radiology, College of Medicine, Seoul (Korea); Chung, Yong-An [The Catholic University of Korea, Department of Radiology, College of Medicine, Seoul (Korea); Incheon St. Mary' s Hospital, Institute of Catholic Integrative Medicine (ICIM), Incheon (Korea); Incheon St. Mary' s Hospital, The Catholic University of Korea, Department of Radiology, Incheon (Korea); Kim, E.E. [University of Texas MD Anderson Cancer Center, Department of Radiology and Nuclear Medicine, Houston, TX (United States)

    2010-08-15

    The aim of this study was to introduce gamma correction pinhole bone scan (GCPBS) to depict specific signs of knee occult fractures (OF) on {sup 99m}Tc-hydroxydiphosphonate (HDP) scan. Thirty-six cases of six different types of knee OF in 27 consecutive patients (male = 20, female = 7, and age = 18-86 years) were enrolled. The diagnosis was made on the basis of a history of acute or subacute knee trauma, local pain, tenderness, cutaneous injury, negative conventional radiography, and positive magnetic resonance imaging (MRI). Because of the impracticability of histological verification of individual OF, MRI was utilized as a gold standard of diagnosis and classification. All patients had {sup 99m}Tc-HDP bone scanning and supplementary GCPBS. GCPBS signs were correlated and compared with those of MRI. The efficacy of gamma correction of ordinary parallel collimator and pinhole collimator scans were collated. Gamma correction pinhole bone scan depicted the signs characteristic of six different types of OF. They were well defined stuffed globular tracer uptake in geographic I fractures (n = 9), block-like uptake in geographic II fractures (n = 7), simple or branching linear uptake in linear cancellous fractures (n = 4), compression in impacted fractures (n = 2), stippled-serpentine uptake in reticular fractures (n = 11), and irregular subcortical uptake in osteochondral fractures (n = 3). All fractures were equally well or more distinctly depicted on GCPBS than on MRI except geographic II fracture, the details of which were not appreciated on GCPBS. Parallel collimator scan also yielded to gamma correction, but the results were inferior to those of the pinhole scan. Gamma correction pinhole bone scan can depict the specific diagnostic signs in six different types of knee occult fractures. The specific diagnostic capability along with the lower cost and wider global availability of bone scanning would make GCPBS an effective alternative. (orig.)

  7. Novel use of gamma correction for precise 99mTc-HDP pinhole bone scan diagnosis and classification of knee occult fractures

    International Nuclear Information System (INIS)

    Bahk, Yong-Whee; Jeon, Ho-Seung; Kim, Jang Min; Park, Jung Mee; Kim, Sung-Hoon; Chung, Soo-Kyo; Chung, Yong-An; Kim, E.E.

    2010-01-01

    The aim of this study was to introduce gamma correction pinhole bone scan (GCPBS) to depict specific signs of knee occult fractures (OF) on 99m Tc-hydroxydiphosphonate (HDP) scan. Thirty-six cases of six different types of knee OF in 27 consecutive patients (male = 20, female = 7, and age = 18-86 years) were enrolled. The diagnosis was made on the basis of a history of acute or subacute knee trauma, local pain, tenderness, cutaneous injury, negative conventional radiography, and positive magnetic resonance imaging (MRI). Because of the impracticability of histological verification of individual OF, MRI was utilized as a gold standard of diagnosis and classification. All patients had 99m Tc-HDP bone scanning and supplementary GCPBS. GCPBS signs were correlated and compared with those of MRI. The efficacy of gamma correction of ordinary parallel collimator and pinhole collimator scans were collated. Gamma correction pinhole bone scan depicted the signs characteristic of six different types of OF. They were well defined stuffed globular tracer uptake in geographic I fractures (n = 9), block-like uptake in geographic II fractures (n = 7), simple or branching linear uptake in linear cancellous fractures (n = 4), compression in impacted fractures (n = 2), stippled-serpentine uptake in reticular fractures (n = 11), and irregular subcortical uptake in osteochondral fractures (n = 3). All fractures were equally well or more distinctly depicted on GCPBS than on MRI except geographic II fracture, the details of which were not appreciated on GCPBS. Parallel collimator scan also yielded to gamma correction, but the results were inferior to those of the pinhole scan. Gamma correction pinhole bone scan can depict the specific diagnostic signs in six different types of knee occult fractures. The specific diagnostic capability along with the lower cost and wider global availability of bone scanning would make GCPBS an effective alternative. (orig.)

  8. Intersection based motion correction of multislice MRI for 3-D in utero fetal brain image formation.

    Science.gov (United States)

    Kim, Kio; Habas, Piotr A; Rousseau, Francois; Glenn, Orit A; Barkovich, Anthony J; Studholme, Colin

    2010-01-01

    In recent years, postprocessing of fast multislice magnetic resonance imaging (MRI) to correct fetal motion has provided the first true 3-D MR images of the developing human brain in utero. Early approaches have used reconstruction based algorithms, employing a two-step iterative process, where slices from the acquired data are realigned to an approximate 3-D reconstruction of the fetal brain, which is then refined further using the improved slice alignment. This two step slice-to-volume process, although powerful, is computationally expensive in needing a 3-D reconstruction, and is limited in its ability to recover subvoxel alignment. Here, we describe an alternative approach which we term slice intersection motion correction (SIMC), that seeks to directly co-align multiple slice stacks by considering the matching structure along all intersecting slice pairs in all orthogonally planned slices that are acquired in clinical imaging studies. A collective update scheme for all slices is then derived, to simultaneously drive slices into a consistent match along their lines of intersection. We then describe a 3-D reconstruction algorithm that, using the final motion corrected slice locations, suppresses through-plane partial volume effects to provide a single high isotropic resolution 3-D image. The method is tested on simulated data with known motions and is applied to retrospectively reconstruct 3-D images from a range of clinically acquired imaging studies. The quantitative evaluation of the registration accuracy for the simulated data sets demonstrated a significant improvement over previous approaches. An initial application of the technique to studying clinical pathology is included, where the proposed method recovered up to 15 mm of translation and 30 degrees of rotation for individual slices, and produced full 3-D reconstructions containing clinically useful additional information not visible in the original 2-D slices.

  9. Using Rose’s metal alloy as a pinhole collimator material in preclinical small-animal imaging: A Monte Carlo evaluation

    International Nuclear Information System (INIS)

    Peterson, Mikael; Strand, Sven-Erik; Ljungberg, Michael

    2015-01-01

    Purpose: Pinhole collimation is the most common method of high-resolution preclinical single photon emission computed tomography imaging. The collimators are usually constructed from dense materials with high atomic numbers, such as gold and platinum, which are expensive and not always flexible in the fabrication step. In this work, the authors have investigated the properties of a fusible alloy called Rose’s metal and its potential in pinhole preclinical imaging. When compared to current standard pinhole materials such as gold and platinum, Rose’s metal has a lower density and a relatively low effective atomic number. However, it is inexpensive, has a low melting point, and does not contract when solidifying. Once cast, the piece can be machined with high precision. The aim of this study was to evaluate the imaging properties for Rose’s metal and compare them with those of standard materials. Methods: After validating their Monte Carlo code by comparing its results with published data and the results from analytical calculations, they investigated different pinhole geometries by varying the collimator material, acceptance angle, aperture diameter, and photon incident angle. The penetration-to-scatter and penetration-to-total component ratios, sensitivity, and the spatial resolution were determined for gold, tungsten, and Rose’s metal for two radionuclides, 99 Tc m and 125 I. Results: The Rose’s metal pinhole-imaging simulations show higher penetration/total and scatter/total ratios. For example, the penetration/total is 50% for gold and 75% for Rose’s metal when simulating 99 Tc m with a 0.3 mm aperture diameter and a 60° acceptance angle. However, the degradation in spatial resolution remained below 10% relative to the spatial resolution for gold for acceptance angles below 40° and aperture diameters larger than 0.5 mm. Conclusions: Extra penetration and scatter associated with Rose’s metal contribute to degradation in the spatial resolution, but

  10. Simultaneous /sup 201/Tl//sup 99m/Tc seven-pinhole tomography in acute myocardial infarction

    Energy Technology Data Exchange (ETDEWEB)

    Krause, T; Schuemichen, C; Fischer, R; Strauss, E; Hoffmann, G

    1986-06-01

    Combined infarction scintigraphy with /sup 201/Tl-chloride and /sup 99m/Tc-pyrophosphate (PPi) by simultaneous seven-pinhole tomography was investigated with a phantom as well as in patients. No artificial defects occurred when the collimator was centered correctly in axial position, but a very high standard of image uniformity and linearity of the gamma camera was required. Artefacts by overlying activity from the skeleton or cardiac blood pool were not observed. All 11 controls showed normal results. Despite a poor depth resolution due to limitations of the system even small areas of partially damaged myocardium could be recognized and correlated three-dimensionally. Of 24 patients with proven myocardial infarction, in 16 both a positive (/sup 99m/Tc-PPi) and a negative (/sup 201/Tl) image was obtained in congruence with the necrosis. 8 patients (33%) showed discordant results providing however additional information on the nature and extent of the necrosis. 4 out of 6 non-transmural infarctions seen by tomography had been suspected clinically.

  11. Varenicline increases in vivo striatal dopamine D2/3 receptor binding: an ultra-high-resolution pinhole [123I]IBZM SPECT study in rats

    International Nuclear Information System (INIS)

    Crunelle, Cleo L.; Wit, Tim C. de; Bruin, Kora de; Ramakers, Ruud M.; Have, Frans van der; Beekman, Freek J.; Brink, Wim van den; Booij, Jan

    2012-01-01

    Introduction: Ex vivo storage phosphor imaging rat studies reported increased brain dopamine D 2/3 receptor (DRD 2/3 ) availability following treatment with varenicline, a nicotinergic drug. However, ex vivo studies can only be performed using cross-sectional designs. Small-animal imaging offers the opportunity to perform serial assessments. We evaluated whether high-resolution pinhole single photon emission computed tomography (SPECT) imaging in rats was able to reproduce previous ex vivo findings. Methods: Rats were imaged for baseline striatal DRD 2/3 availability using ultra-high-resolution pinhole SPECT (U-SPECT-II) and [ 123 I]IBZM as a radiotracer, and randomized to varenicline (n=7; 2 mg/kg) or saline (n=7). Following 2 weeks of treatment, a second scan was acquired. Results: Significantly increased striatal DRD 2/3 availability was found following varenicline treatment compared to saline (time⁎treatment effect): posttreatment difference in binding potential between groups corrected for initial baseline differences was 2.039 (P=.022), indicating a large effect size (d=1.48). Conclusions: Ultra-high-resolution pinhole SPECT can be used to assess varenicline-induced changes in DRD 2/3 availability in small laboratory animals over time. Future small-animal studies should include imaging techniques to enable repeated within-subjects measurements and reduce the amount of animals.

  12. Measurment of radon, thoron and their progeny in indoor environment of Mohali, Punjab, Northern India, using pinhole dosimeters

    Directory of Open Access Journals (Sweden)

    Mehta Vimal

    2016-01-01

    Full Text Available The health hazards of radon and its decay products above certain levels are well known. However, for any preventive measures to be taken, we have to be aware of radon levels of that particular area. Measurement of radon and its decay products in indoor environments is an important aspect of assessing indoor air quality and health conditions associated with it. Keeping this in mind, measurements of radon, thoron and their progeny concentrations were carried out in Mohali, Northern India, using pinhole-based twin cup dosimeters. Radon exhalation rates of soil samples in the dwellings/areas were measured via an active technique of a continuous radon monitor. The indoor radon concentration in Mohali varied from 15.03 ± 0.61 Bq/m3 to 39.21 ± 1.46 Bq/m3 with an average of 26.95 Bq/m3 ,while thoron concentration in the same dwellings varied from 9.62 ± 0.54 Bq/m3 to 52.84 ± 2.77 Bq/m3 with an average of 31.09 Bq/m3. Radon progeny levels in dwellings under study varied from 1.63 to 4.24 mWL, with an average of 2.94 mWL, while thoron progeny levels varied from 0.26 to 1.43 mWL , with an average of 0.84 mWL. The annual dose received by the inhabitants of dwellings under study varied from 0.78 to 2.36 mSv, with an average of 1.61 mSv. The in situ gamma dose rate varied from 0.12 to 0.32 mSv/h.

  13. Early and delayed pinhole MIBI SPECT in detecting hyperfunctioning parathyroid glands: a comparison with peroperative γ probe.

    Science.gov (United States)

    Gültekin, Salih Sinan; Kir, Metin; Tuğ, Tuğbay; Demirer, Seher; Genç, Yasemin

    2011-10-01

    This study was conducted to evaluate the early and delayed pinhole MIBI single photon emission computed tomography (pSPECT) images in detecting hyperfunctioning parathyroid glands, to make a comparison with peroperative γ probe (GP) findings. Planar, early, and delayed pSPECT scans and skin in-vivo and ex-vivo GP counts were obtained in 22 patients with hyperparathyroidism. All data were analyzed statistically on the basis of localization of the lesions, using the histopathological findings as the gold standard. Histopathological examinations revealed 18 of 44 adenomas, 18 of 44 hyperplasic glands, two of 44 lymph nodules, five of 44 thyroid nodules, and one of 44 normal parathyroid glands. Sensitivity and specificity were found to be 36 and 100% for planar, 69 and 75% for early pSPECT, 86 and 88% for delayed pSPECT scans, and similarly, 78 and 75% on skin, 92 and 75% in-vivo and 83 and 100% ex-vivo GP counts, respectively. For distinction ability of GP counts between three groups of lesions, there was a statistically significant difference among the three groups for ex-vivo GP counts but not between groups of adenomas and hyperplasic lesions for in-vivo GP counts. Early and delayed pSPECT scans play a complementary role on the planar scans. Delayed pSPECT scans and in-vivo GP counts are equally valuable to localize both single and multiple hyperfunctioning parathyroid glands. Ex-vivo GP counts seem to be better for making a distinction among types of lesions.

  14. Prevention of short circuits in solution-processed OLED devices

    NARCIS (Netherlands)

    Jolt Oostra, A.; Blom, P.W.M.; Michels, J.J.

    2014-01-01

    Pinholes in the emitting layer of an organic light emitting diode (OLED), e.g. induced by particle contamination or processing flaws, lead to direct contact between the hole-injection layer (HIL) and the cathode. The resulting short circuits give rise to catastrophic device failure. We demonstrate

  15. Spatially resolvable optical emission spectrometer for analyzing density uniformity of semiconductor process plasma

    International Nuclear Information System (INIS)

    Oh, Changhoon; Ryoo, Hoonchul; Lee, Hyungwoo; Hahn, Jae W.; Kim, Se-Yeon; Yi, Hun-Jung

    2010-01-01

    We proposed a spatially resolved optical emission spectrometer (SROES) for analyzing the uniformity of plasma density for semiconductor processes. To enhance the spatial resolution of the SROES, we constructed a SROES system using a series of lenses, apertures, and pinholes. We calculated the spatial resolution of the SROES for the variation of pinhole size, and our calculated results were in good agreement with the measured spatial variation of the constructed SROES. The performance of the SROES was also verified by detecting the correlation between the distribution of a fluorine radical in inductively coupled plasma etch process and the etch rate of a SiO 2 film on a silicon wafer.

  16. Rapid construction of pinhole SPECT system matrices by distance-weighted Gaussian interpolation method combined with geometric parameter estimations

    International Nuclear Information System (INIS)

    Lee, Ming-Wei; Chen, Yi-Chun

    2014-01-01

    In pinhole SPECT applied to small-animal studies, it is essential to have an accurate imaging system matrix, called H matrix, for high-spatial-resolution image reconstructions. Generally, an H matrix can be obtained by various methods, such as measurements, simulations or some combinations of both methods. In this study, a distance-weighted Gaussian interpolation method combined with geometric parameter estimations (DW-GIMGPE) is proposed. It utilizes a simplified grid-scan experiment on selected voxels and parameterizes the measured point response functions (PRFs) into 2D Gaussians. The PRFs of missing voxels are interpolated by the relations between the Gaussian coefficients and the geometric parameters of the imaging system with distance-weighting factors. The weighting factors are related to the projected centroids of voxels on the detector plane. A full H matrix is constructed by combining the measured and interpolated PRFs of all voxels. The PRFs estimated by DW-GIMGPE showed similar profiles as the measured PRFs. OSEM reconstructed images of a hot-rod phantom and normal rat myocardium demonstrated the effectiveness of the proposed method. The detectability of a SKE/BKE task on a synthetic spherical test object verified that the constructed H matrix provided comparable detectability to that of the H matrix acquired by a full 3D grid-scan experiment. The reduction in the acquisition time of a full 1.0-mm grid H matrix was about 15.2 and 62.2 times with the simplified grid pattern on 2.0-mm and 4.0-mm grid, respectively. A finer-grid H matrix down to 0.5-mm spacing interpolated by the proposed method would shorten the acquisition time by 8 times, additionally. -- Highlights: • A rapid interpolation method of system matrices (H) is proposed, named DW-GIMGPE. • Reduce H acquisition time by 15.2× with simplified grid scan and 2× interpolation. • Reconstructions of a hot-rod phantom with measured and DW-GIMGPE H were similar. • The imaging study of normal

  17. {sup 99m}Tc-HDP Pinhole Bone Scan Features of Undetached Osteochondritis Dissecans of the Femoral Condyle: Report of a Case with Radiography, CT, and MRI Correlation

    Energy Technology Data Exchange (ETDEWEB)

    Bahk, Yong Whee [Sung Ae Hospital, Seoul (Korea, Republic of); Choi, Woo Hee [Seoul St. Mary' s Hospital, Catholic University Medical School, Seoul (Korea, Republic of)

    2009-02-15

    OCD may be initiated by arrest of bone growth and subchondral osteosclerosis followed by either cartilage hypertrophy with calcification or enfolding with osteochondral bridging. Diagnosis can be made in most instances using magnetic resonance imaging (MRI) or computed tomography (CT) or invasive arthroscopy. As to usefulness of conventional radiography (CR) opinions diverge as some held it to be of limited value while others valuable. The controversy seems to be due to semantic confusion of OCD from osteonecrosis (ON) which are different entities. This report will describe a case of undetached OCD occurred in the medial femoral condyle in a middle-aged female. It was free of symptom and incidentally discovered on {sup 99m}Tc-HDP pinhole scan performed for patellar injury. Pinhole scan findings of OCD are correlated to those of CR, CT, and MRI. An electronic search of literature failed to reveal earlier publication of bone scan features of undetached OCD. Pathologically, OCD differs from ON in that the fragment in the former condition comes off from a normal vascular bony bed while that in the latter separates from an avascular bony bed. Indeed, bone fragment in ON is devascularized but that in OCD maintains vascularity until weighted images, respectively and the halo showed low signal intensity on both T1 and T2 images.

  18. Optimization of a collimator size for the pin-hole camera of X-rays, and proposal of a method to correct degradations of efficiencies in neighboring parts of the image

    International Nuclear Information System (INIS)

    Hayashi, Hiroaki; Nishihara, Sadamitsu; Taniuchi, Shou; Kamiya, Naotaka

    2012-01-01

    A visual image of the scattered X-ray distributions gives us useful information for beginners to study radiation physics. A pin-hole camera for X-rays can be made by use of simple materials as well as a two-dimensional X-ray detector (imaging plate: IP). In contrast with a pin-hole camera for the visible radiations, a pin-hole camera for X-rays uses a collimator, having a sufficient thickness to reduce X-rays. This design causes the following problem: in the case in which the X-rays are incident to the collimator from the diagonal direction, the some X-rays are absorbed by the wall of the collimator. Namely, the images in the surrounding part of the IP are underrepresented. The aim of this study is to suggest a correction method of the underrepresentation. We used a pin-hole camera (320 mm(long)×270 mm(wide)×300 mm(depth)) by means of the clinically applied IP (10×12 inch). In order to determine proper conditions for a size of collimators (pin-hole), experiments using medical X-ray equipments were carried out. The efficiencies and resolutions were experimentally determined for the collimator sizes of 2 to 8 mm φ . Then, images of scattered X-ray distributions were measured by the irradiation of a head phantom, and considerations were taken for a practical use of the pin-hole camera. Moreover, an exponential absorption of X-rays in the phantom was visualized by our camera in order to indicate a potential of quantitative analysis based on the image of scattered X-ray distributions. (author)

  19. Introduction to computer image processing

    Science.gov (United States)

    Moik, J. G.

    1973-01-01

    Theoretical backgrounds and digital techniques for a class of image processing problems are presented. Image formation in the context of linear system theory, image evaluation, noise characteristics, mathematical operations on image and their implementation are discussed. Various techniques for image restoration and image enhancement are presented. Methods for object extraction and the problem of pictorial pattern recognition and classification are discussed.

  20. Photon event distribution sampling: an image formation technique for scanning microscopes that permits tracking of sub-diffraction particles with high spatial and temporal resolutions.

    Science.gov (United States)

    Larkin, J D; Publicover, N G; Sutko, J L

    2011-01-01

    In photon event distribution sampling, an image formation technique for scanning microscopes, the maximum likelihood position of origin of each detected photon is acquired as a data set rather than binning photons in pixels. Subsequently, an intensity-related probability density function describing the uncertainty associated with the photon position measurement is applied to each position and individual photon intensity distributions are summed to form an image. Compared to pixel-based images, photon event distribution sampling images exhibit increased signal-to-noise and comparable spatial resolution. Photon event distribution sampling is superior to pixel-based image formation in recognizing the presence of structured (non-random) photon distributions at low photon counts and permits use of non-raster scanning patterns. A photon event distribution sampling based method for localizing single particles derived from a multi-variate normal distribution is more precise than statistical (Gaussian) fitting to pixel-based images. Using the multi-variate normal distribution method, non-raster scanning and a typical confocal microscope, localizations with 8 nm precision were achieved at 10 ms sampling rates with acquisition of ~200 photons per frame. Single nanometre precision was obtained with a greater number of photons per frame. In summary, photon event distribution sampling provides an efficient way to form images when low numbers of photons are involved and permits particle tracking with confocal point-scanning microscopes with nanometre precision deep within specimens. © 2010 The Authors Journal of Microscopy © 2010 The Royal Microscopical Society.

  1. Measurement of the iodine uptake by the thyroid: comparative analysis between the gamma camera system with 'pinhole' collimator and 13S002 system

    International Nuclear Information System (INIS)

    Silva, Carlos Borges da; Mello, Rossana Corbo R. de; Rebelo, Ana Maria O.

    2002-01-01

    The thyroid uptake measurements are common in medical uses and are considered a direct and precise form of diagnostic, however, different results have been observed as measurements of thyroid uptake are taken using distinct equipment. This study attempts to find the cause of the differences between a thyroid uptake probe and a gamma camera. These discrepancies can be associated to the different patients samples, equipment's problems or operator procedures errors. This work presents the results of comparative uptake measurements performed in a neck phantom and a 4-hour thyroid uptake study in 40 patients, using a Gamma Camera Ohio Nuclear model Sigma 410 with a pinhole collimator and Nuclear Medicine System model 13S002, developed by Instituto de Engenharia Nuclear. The results observed show that in spite of non satisfactory results commented in literature, both the System 13S002 and System Gamma Camera Ohio can be used in uptake thyroid diagnostic with statistical confidence degree of 99 %. (author)

  2. Intersection Based Motion Correction of Multi-Slice MRI for 3D in utero Fetal Brain Image Formation

    Science.gov (United States)

    Kim, Kio; Habas, Piotr A.; Rousseau, Francois; Glenn, Orit A.; Barkovich, Anthony J.; Studholme, Colin

    2012-01-01

    In recent years post-processing of fast multi-slice MR imaging to correct fetal motion has provided the first true 3D MR images of the developing human brain in utero. Early approaches have used reconstruction based algorithms, employing a two step iterative process, where slices from the acquired data are re-aligned to an approximate 3D reconstruction of the fetal brain, which is then refined further using the improved slice alignment. This two step slice-to-volume process, although powerful, is computationally expensive in needing a 3D reconstruction, and is limited in its ability to recover sub-voxel alignment. Here, we describe an alternative approach which we term slice intersection motion correction (SIMC), that seeks to directly co-align multiple slice stacks by considering the matching structure along all intersecting slice pairs in all orthogonally planned slices that are acquired in clinical imaging studies. A collective update scheme for all slices is then derived, to simultaneously drive slices into a consistent match along their lines of intersection. We then describe a 3D reconstruction algorithm that, using the final motion corrected slice locations, suppresses through-plane partial volume effects to provide a single high isotropic resolution 3D image. The method is tested on simulated data with known motions and is applied to retrospectively reconstruct 3D images from a range of clinically acquired imaging studies. The quantitative evaluation of the registration accuracy for the simulated data sets demonstrated a significant improvement over previous approaches. An initial application of the technique to studying clinical pathology is included, where the proposed method recovered up to 15 mm of translation and 30 degrees of rotation for individual slices, and produced full 3D reconstructions containing clinically useful additional information not visible in the original 2D slices. PMID:19744911

  3. In vivo assessment of 111In labelled lymphocyte gut homing in a TNBS colitis mouse model determined by dedicated animal pinhole SPECT

    International Nuclear Information System (INIS)

    Bennink, R.J.; Bruin, C.M. de; Montfrans, C. van; Jonge, W.J. de; Deventer, S.J. van; Velde, A.A. te

    2002-01-01

    Aims: The increasing knowledge of the molecular basis of leukocyte trafficking results in the development of novel anti-inflammatory strategies for inflammatory bowel disease (IBD). For optimal evaluation of therapy efficacy, information about inflammatory activity in bowel segments or lymphocyte recirculation and kinetics in the follow-up of experimental treatment for IBD is needed. The aim of this study was to evaluate a non-invasive scintigraphic technique, able to assess lymphocyte trafficking in a trinitrobenzene sulfonic acid (TNBS) induced mouse colitis model of IBD. Materials and Methods: TNBS sensitised and non-sensitised murine total splenocytes, isolated from donor TNBS colitis or placebo treated BALB/c mice, were labelled in vitro with 111 In-oxine and injected intravenously into recipient BALB/c mice with TNBS-induced colitis or healthy BALB/c mice instilled with saline. Biodistribution and specific radioactive uptake, representing transferred cells, was determined by serial dedicated animal planar scintigraphy and pinhole SPECT of the abdomen 4, 24 and 48h post injection of labelled cells. Moreover, the severity of inflammation in recipient mice was determined by histological scoring. Results: Lymphocyte migration to the inflamed colon of recipient mice increased in time and was maximal at 48h after administration of the 111 In-oxine labelled donor splenocytes. The highest specific radioactive uptake ratio in the colon after 48h was observed in recipient mice with TNBS colitis that received TNBS sensitised lymphocytes (saline vs. TNBS colitis resp. 0.22 ± 0.035 and 0.51 ± 0.033 mean ± SEM p<0.01). Histological scoring confirmed colitis in the TNBS colitis recipient groups and excluded colitis in the saline instilled recipient groups. TNBS colitis recipient mice that received sensitised lymphocytes had a more severe colitis upon histological evaluation as compared with TNBS colitis recipient mice receiving non-sensitised cells (mean histological

  4. Imaging Formation Algorithm of the Ground and Space-Borne Hybrid BiSAR Based on Parameters Estimation from Direct Signal

    Directory of Open Access Journals (Sweden)

    Qingjun Zhang

    2014-01-01

    Full Text Available This paper proposes a novel image formation algorithm for the bistatic synthetic aperture radar (BiSAR with the configuration of a noncooperative transmitter and a stationary receiver in which the traditional imaging algorithm failed because the necessary imaging parameters cannot be estimated from the limited information from the noncooperative data provider. In the new algorithm, the essential parameters for imaging, such as squint angle, Doppler centroid, and Doppler chirp-rate, will be estimated by full exploration of the recorded direct signal (direct signal is the echo from satellite to stationary receiver directly from the transmitter. The Doppler chirp-rate is retrieved by modeling the peak phase of direct signal as a quadratic polynomial. The Doppler centroid frequency and the squint angle can be derived from the image contrast optimization. Then the range focusing, the range cell migration correction (RCMC, and the azimuth focusing are implemented by secondary range compression (SRC and the range cell migration, respectively. At last, the proposed algorithm is validated by imaging of the BiSAR experiment configured with china YAOGAN 10 SAR as the transmitter and the receiver platform located on a building at a height of 109 m in Jiangsu province. The experiment image with geometric correction shows good accordance with local Google images.

  5. Medical Imaging 4: Image formation

    International Nuclear Information System (INIS)

    Schneider, R.H.

    1990-01-01

    This book contains papers relating to the 1990 meeting of The International Society for Optical Engineering. Included are the following papers: Effect of protective layer on Resolution Properties of Photostimulable Phosphor Detector for Digital Radiographic System, Neural Network Scatter Correction Technique for Digital Radiography, Use of Computer Radiography for Portal Imaging

  6. Demonstration of a large-size horizontal light-field display based on the LED panel and the micro-pinhole unit array

    Science.gov (United States)

    Yang, Le; Sang, Xinzhu; Yu, Xunbo; Liu, Boyang; Liu, Li; Yang, Shenwu; Yan, Binbin; Du, Jingyan; Gao, Chao

    2018-05-01

    A 54-inch horizontal-parallax only light-field display based on the light-emitting diode (LED) panel and the micro-pinhole unit array (MPUA) is demonstrated. Normally, the perceived 3D effect of the three-dimensional (3D) display with smooth motion parallax and abundant light-field information can be enhanced with increasing the density of viewpoints. However, the density of viewpoints is inversely proportional to the spatial display resolution for the conventional integral imaging. Here, a special MPUA is designed and fabricated, and the displayed 3D scene constructed by the proposed horizontal light-field display is presented. Compared with the conventional integral imaging, both the density of horizontal viewpoints and the spatial display resolution are significantly improved. In the experiment, A 54-inch horizontal light-field display with 42.8° viewing angle based on the LED panel with the resolution of 1280 × 720 and the MPUA is realized, which can provide natural 3D visual effect to observers with high quality.

  7. Simultaneous thallium-201/technetium-99m pyrophosphate tomography in patients with acute myocardial infarction: comparison of rotational SPECT and seven pinhole tomography

    International Nuclear Information System (INIS)

    Krause, T.; Schuemichen, C.; Beck, A.; Moser, E.; Zeiher, A.

    1992-01-01

    Simultaneous Tl-201/Tc-99m pyrophosphate (PPi) tomography was compared to Tc-99m PPi tomography and rotational SPECT (SPECT) was compared to seven pinhole tomography (9-PHT), respectively, in 19 patients with acute myocardial infarction (AMI). The results were correlated to electrocardiographic and angiographic findings. With Tl-201/Tc-99, PPi, all infarctions were detected and site of infarction was determined, independent of the tomographic technique used. There was no significant difference between the two acquisition techniques 7-PHT and SPECT concerning spatial extent of Tc-99m PPi accumulation and the uptake ratio. However, using only Tc-99m PPi without Tl-201 as anatomical marker, SPECT detected 15/19 infarctions. In 7 of these 15 cases infarction site was correctly determined. 7-PHT detected 11/19 and site was correctly determined in 9/11 infarctions. Myocardial infarctions which failed diagnosis using Tc-99m PPi alone showed significantly smaller spatial extent of Tc-99m PPi accumulation and necrosis to blood pool ratio was lower as assessed by Tl201/Tc-99m PPi tomography. In conclusions, tomography using simultaneous Tl-201/Tc-99m PPi imaging is a reliable technique for diagnosis and localization of AMI. For this reason, results obtained with SPECT and 7-PHT are comparable. Independent of the tomographic technique used, combined imaging is superior to Tc-99m PPi alone without Tl-201 as additional anatomical marker (orig./MG) [de

  8. A super-high angular resolution principle for coded-mask X-ray imaging beyond the diffraction limit of a single pinhole

    International Nuclear Information System (INIS)

    Zhang Chen; Zhang Shuangnan

    2009-01-01

    High angular resolution X-ray imaging is always useful in astrophysics and solar physics. In principle, it can be performed by using coded-mask imaging with a very long mask-detector distance. Previously, the diffraction-interference effect was thought to degrade coded-mask imaging performance dramatically at the low energy end with its very long mask-detector distance. The diffraction-interference effect is described with numerical calculations, and the diffraction-interference cross correlation reconstruction method (DICC) is developed in order to overcome the imaging performance degradation. Based on the DICC, a super-high angular resolution principle (SHARP) for coded-mask X-ray imaging is proposed. The feasibility of coded mask imaging beyond the diffraction limit of a single pinhole is demonstrated with simulations. With the specification that the mask element size is 50 x 50 μm 2 and the mask-detector distance is 50 m, the achieved angular resolution is 0.32 arcsec above about 10 keV and 0.36 arcsec at 1.24 keV (λ = 1 nm), where diffraction cannot be neglected. The on-axis source location accuracy is better than 0.02 arcsec. Potential applications for solar observations and wide-field X-ray monitors are also briefly discussed. (invited reviews)

  9. In vivo detection of small tumour lesions by multi-pinhole SPECT applying a (99m)Tc-labelled nanobody targeting the Epidermal Growth Factor Receptor.

    Science.gov (United States)

    Krüwel, Thomas; Nevoltris, Damien; Bode, Julia; Dullin, Christian; Baty, Daniel; Chames, Patrick; Alves, Frauke

    2016-02-25

    The detection of tumours in an early phase of tumour development in combination with the knowledge of expression of tumour markers such as epidermal growth factor receptor (EGFR) is an important prerequisite for clinical decisions. In this study we applied the anti-EGFR nanobody (99m)Tc-D10 for visualizing small tumour lesions with volumes below 100 mm(3) by targeting EGFR in orthotopic human mammary MDA-MB-468 and MDA-MB-231 and subcutaneous human epidermoid A431 carcinoma mouse models. Use of nanobody (99m)Tc-D10 of a size as small as 15.5 kDa enables detection of tumours by single photon emission computed tomography (SPECT) imaging already 45 min post intravenous administration with high tumour uptake (>3% ID/g) in small MDA-MB-468 and A431 tumours, with tumour volumes of 52.5 mm(3) ± 21.2 and 26.6 mm(3) ± 16.7, respectively. Fast blood clearance with a serum half-life of 4.9 min resulted in high in vivo contrast and ex vivo tumour to blood and tissue ratios. In contrast, no accumulation of (99m)Tc-D10 in MDA-MB-231 tumours characterized by a very low expression of EGFR was observed. Here we present specific and high contrast in vivo visualization of small human tumours overexpressing EGFR by preclinical multi-pinhole SPECT shortly after administration of anti-EGFR nanobody (99m)Tc-D10.

  10. In vivo detection of small tumour lesions by multi-pinhole SPECT applying a 99mTc-labelled nanobody targeting the Epidermal Growth Factor Receptor

    Science.gov (United States)

    Krüwel, Thomas; Nevoltris, Damien; Bode, Julia; Dullin, Christian; Baty, Daniel; Chames, Patrick; Alves, Frauke

    2016-01-01

    The detection of tumours in an early phase of tumour development in combination with the knowledge of expression of tumour markers such as epidermal growth factor receptor (EGFR) is an important prerequisite for clinical decisions. In this study we applied the anti-EGFR nanobody 99mTc-D10 for visualizing small tumour lesions with volumes below 100 mm3 by targeting EGFR in orthotopic human mammary MDA-MB-468 and MDA-MB-231 and subcutaneous human epidermoid A431 carcinoma mouse models. Use of nanobody 99mTc-D10 of a size as small as 15.5 kDa enables detection of tumours by single photon emission computed tomography (SPECT) imaging already 45 min post intravenous administration with high tumour uptake (>3% ID/g) in small MDA-MB-468 and A431 tumours, with tumour volumes of 52.5 mm3 ± 21.2 and 26.6 mm3 ± 16.7, respectively. Fast blood clearance with a serum half-life of 4.9 min resulted in high in vivo contrast and ex vivo tumour to blood and tissue ratios. In contrast, no accumulation of 99mTc-D10 in MDA-MB-231 tumours characterized by a very low expression of EGFR was observed. Here we present specific and high contrast in vivo visualization of small human tumours overexpressing EGFR by preclinical multi-pinhole SPECT shortly after administration of anti-EGFR nanobody 99mTc-D10. PMID:26912069

  11. Design of a Multi-Pinhole Collimator for I-123 DaTscan Imaging on Dual-Headed SPECT Systems in Combination with a Fan-Beam Collimator.

    Science.gov (United States)

    King, Michael A; Mukherjee, Joyeeta M; Könik, Arda; Zubal, I George; Dey, Joyoni; Licho, Robert

    2016-02-01

    For the 2011 FDA approved Parkinson's Disease (PD) SPECT imaging agent I-123 labeled DaTscan, the volume of interest (VOI) is the interior portion of the brain. However imaging of the occipital lobe is also required with PD for calculation of the striatal binding ratio (SBR), a parameter of significance in early diagnosis, differentiation of PD from other disorders with similar clinical presentations, and monitoring progression. Thus we propose the usage of a combination of a multi-pinhole (MPH) collimator on one head of the SPECT system and a fan-beam on the other. The MPH would be designed to provide high resolution and sensitivity for imaging of the interior portion of the brain. The fan-beam collimator would provide lower resolution but complete sampling of the brain addressing data sufficiency and allowing a volume-of-interest to be defined over the occipital lobe for calculation of SBR's. Herein we focus on the design of the MPH component of the combined system. Combined reconstruction will be addressed in a subsequent publication. An analysis of 46 clinical DaTscan studies was performed to provide information to define the VOI, and design of a MPH collimator to image this VOI. The system spatial resolution for the MPH was set to 4.7 mm, which is comparable to that of clinical PET systems, and significantly smaller than that of fan-beam collimators employed in SPECT. With this set, we compared system sensitivities for three aperture array designs, and selected the 3 × 3 array due to it being the highest of the three. The combined sensitivity of the apertures for it was similar to that of an ultra-high resolution fan-beam (LEUHRF) collimator, but smaller than that of a high-resolution fan-beam collimator (LEHRF). On the basis of these results we propose the further exploration of this design through simulations, and the development of combined MPH and fan-beam reconstruction.

  12. Digital image processing mathematical and computational methods

    CERN Document Server

    Blackledge, J M

    2005-01-01

    This authoritative text (the second part of a complete MSc course) provides mathematical methods required to describe images, image formation and different imaging systems, coupled with the principle techniques used for processing digital images. It is based on a course for postgraduates reading physics, electronic engineering, telecommunications engineering, information technology and computer science. This book relates the methods of processing and interpreting digital images to the 'physics' of imaging systems. Case studies reinforce the methods discussed, with examples of current research

  13. Design and Manufacturing of a High-Precision Sun Tracking System Based on Image Processing

    Directory of Open Access Journals (Sweden)

    Kianoosh Azizi

    2013-01-01

    Full Text Available Concentration solar arrays require greater solar tracking precision than conventional photovoltaic arrays. This paper presents a high precision low cost dual axis sun tracking system based on image processing for concentration photovoltaic applications. An imaging device is designed according to the principle of pinhole imaging, making sun rays to be received on a screen through pinhole and to be a sun spot. The location of the spot is used to adjust the orientation of the solar panel. A fuzzy logic controller is developed to achieve this goal. A prototype was built, and experimental results have proven the good performance of the proposed system and low error of tracking. The operation of this system is independent of geographical location, initial calibration, and periodical regulations.

  14. Scatter and crosstalk corrections for 99mTc/123I dual-radionuclide imaging using a CZT SPECT system with pinhole collimators

    International Nuclear Information System (INIS)

    Fan, Peng; Hutton, Brian F.; Holstensson, Maria; Ljungberg, Michael; Hendrik Pretorius, P.; Prasad, Rameshwar; Liu, Chi; Ma, Tianyu; Liu, Yaqiang; Wang, Shi; Thorn, Stephanie L.; Stacy, Mitchel R.; Sinusas, Albert J.

    2015-01-01

    Purpose: The energy spectrum for a cadmium zinc telluride (CZT) detector has a low energy tail due to incomplete charge collection and intercrystal scattering. Due to these solid-state detector effects, scatter would be overestimated if the conventional triple-energy window (TEW) method is used for scatter and crosstalk corrections in CZT-based imaging systems. The objective of this work is to develop a scatter and crosstalk correction method for 99m Tc/ 123 I dual-radionuclide imaging for a CZT-based dedicated cardiac SPECT system with pinhole collimators (GE Discovery NM 530c/570c). Methods: A tailing model was developed to account for the low energy tail effects of the CZT detector. The parameters of the model were obtained using 99m Tc and 123 I point source measurements. A scatter model was defined to characterize the relationship between down-scatter and self-scatter projections. The parameters for this model were obtained from Monte Carlo simulation using SIMIND. The tailing and scatter models were further incorporated into a projection count model, and the primary and self-scatter projections of each radionuclide were determined with a maximum likelihood expectation maximization (MLEM) iterative estimation approach. The extracted scatter and crosstalk projections were then incorporated into MLEM image reconstruction as an additive term in forward projection to obtain scatter- and crosstalk-corrected images. The proposed method was validated using Monte Carlo simulation, line source experiment, anthropomorphic torso phantom studies, and patient studies. The performance of the proposed method was also compared to that obtained with the conventional TEW method. Results: Monte Carlo simulations and line source experiment demonstrated that the TEW method overestimated scatter while their proposed method provided more accurate scatter estimation by considering the low energy tail effect. In the phantom study, improved defect contrasts were observed with both

  15. Scatter and crosstalk corrections for {sup 99m}Tc/{sup 123}I dual-radionuclide imaging using a CZT SPECT system with pinhole collimators

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Peng [Department of Diagnostic Radiology, Yale University, New Haven, Connecticut 06520 and Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Hutton, Brian F. [Institute of Nuclear Medicine, University College London, London WC1E 6BT, United Kingdom and Centre for Medical Radiation Physics, University of Wollongong, New South Wales 2522 (Australia); Holstensson, Maria [Department of Nuclear Medicine, Karolinska University Hospital, Stockholm 14186 (Sweden); Ljungberg, Michael [Department of Medical Radiation Physics, Lund University, Lund 222 41 (Sweden); Hendrik Pretorius, P. [Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts 01655 (United States); Prasad, Rameshwar; Liu, Chi, E-mail: chi.liu@yale.edu [Department of Diagnostic Radiology, Yale University, New Haven, Connecticut 06520 (United States); Ma, Tianyu; Liu, Yaqiang; Wang, Shi [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Thorn, Stephanie L.; Stacy, Mitchel R.; Sinusas, Albert J. [Department of Internal Medicine, Yale Translational Research Imaging Center, Yale University, New Haven, Connecticut 06520 (United States)

    2015-12-15

    Purpose: The energy spectrum for a cadmium zinc telluride (CZT) detector has a low energy tail due to incomplete charge collection and intercrystal scattering. Due to these solid-state detector effects, scatter would be overestimated if the conventional triple-energy window (TEW) method is used for scatter and crosstalk corrections in CZT-based imaging systems. The objective of this work is to develop a scatter and crosstalk correction method for {sup 99m}Tc/{sup 123}I dual-radionuclide imaging for a CZT-based dedicated cardiac SPECT system with pinhole collimators (GE Discovery NM 530c/570c). Methods: A tailing model was developed to account for the low energy tail effects of the CZT detector. The parameters of the model were obtained using {sup 99m}Tc and {sup 123}I point source measurements. A scatter model was defined to characterize the relationship between down-scatter and self-scatter projections. The parameters for this model were obtained from Monte Carlo simulation using SIMIND. The tailing and scatter models were further incorporated into a projection count model, and the primary and self-scatter projections of each radionuclide were determined with a maximum likelihood expectation maximization (MLEM) iterative estimation approach. The extracted scatter and crosstalk projections were then incorporated into MLEM image reconstruction as an additive term in forward projection to obtain scatter- and crosstalk-corrected images. The proposed method was validated using Monte Carlo simulation, line source experiment, anthropomorphic torso phantom studies, and patient studies. The performance of the proposed method was also compared to that obtained with the conventional TEW method. Results: Monte Carlo simulations and line source experiment demonstrated that the TEW method overestimated scatter while their proposed method provided more accurate scatter estimation by considering the low energy tail effect. In the phantom study, improved defect contrasts were

  16. Optical fiber sensors for image formation in radiodiagnostic - preliminary essays; Sensores a fibra optica para formacao de imagens em radiodiagnostico - ensaios preliminares

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Cesar C. de; Werneck, Marcelo M. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Biomedica

    1998-07-01

    This work describes preliminary experiments that will bring subsidies to analyze the capability to implement a system able to capture radiological images with new sensor system, comprised by FOs scanning process and I-CCD camera. These experiments have the main objective to analyze the optical response from FOs bundle, with several typos of scintillators associated with them, when it is submitted to medical x-rays exposition. (author)

  17. The NJOY Nuclear Data Processing System, Version 2016

    Energy Technology Data Exchange (ETDEWEB)

    Macfarlane, Robert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Muir, Douglas W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Boicourt, R. M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kahler, III, Albert Comstock [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Conlin, Jeremy Lloyd [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-01-09

    The NJOY Nuclear Data Processing System, version 2016, is a comprehensive computer code package for producing pointwise and multigroup cross sections and related quantities from evaluated nuclear data in the ENDF-4 through ENDF-6 legacy card-image formats. NJOY works with evaluated files for incident neutrons, photons, and charged particles, producing libraries for a wide variety of particle transport and reactor analysis codes.

  18. Analysis of the gammaholographic image formation

    International Nuclear Information System (INIS)

    Fonroget, J.; Roucayrol, J.C.; Perrin, J.; Belvaux, Y.; Paris-11 Univ., 91 - Orsay

    1975-01-01

    Gammaholography, or coded opening gammagraphy, is a new gammagraphic method in which the standard collimators are replaced by one or more modulator screens placed between the detector and the radioactive object. The recording obtained is a coded image or incoherent hologram which contains three-dimensional information on the object and can be decoded analogically in a very short time. The formation of the image has been analyzed in the coding and optical decoding phases in the case of a single coding screen modulated according to a Fresnel zoned lattice. The analytical expression established for the modulation transfer function (MTF) of the system can be used to study, by computerized simulation, the influence of the number of zones on the quality of the image [fr

  19. The optics of microscope image formation.

    Science.gov (United States)

    Wolf, David E

    2013-01-01

    Although geometric optics gives a good understanding of how the microscope works, it fails in one critical area, which is explaining the origin of microscope resolution. To accomplish this, one must consider the microscope from the viewpoint of physical optics. This chapter describes the theory of the microscope-relating resolution to the highest spatial frequency that a microscope can collect. The chapter illustrates how Huygens' principle or construction can be used to explain the propagation of a plane wave. It is shown that this limit increases with increasing numerical aperture (NA). As a corollary to this, resolution increases with decreasing wavelength because of how NA depends on wavelength. The resolution is higher for blue light than red light. Resolution is dependent on contrast, and the higher the contrast, the higher the resolution. This last point relates to issues of signal-to-noise and dynamic range. The use of video and new digital cameras has necessitated redefining classical limits such as those of Rayleigh's criterion. Copyright © 2007 Elsevier Inc. All rights reserved.

  20. Plasma processed coating of laser fusion targets

    International Nuclear Information System (INIS)

    Johnson, W.L.; Letts, S.A.; Myers, D.W.; Crane, J.K.; Illige, J.D.; Hatcher, C.W.

    1979-01-01

    Coatings for laser fusion targets have been deposited in an inductively coupled discharge device by plasma polymerization. Two feed gases were used: perfluoro-2-butene, which produced a fluorocarbon coating (CF 1 3 ) with a density of 1.8 g/cc, and trans-2-butene which produced a hydrocarbon coating (CH 1 3 ) with a density of 1.0 g/cc. Uniform pin-hole free films have been deposited to a thickness of up to 30 μm of fluorocarbon and up to 110 μm of hydrocarbon. The effect of process variables on surface smoothness has been investigated. The basic defect in the coating has been found to result from shadowing by a small surface irregularity in an anisotropic coating flux

  1. 99mTc labelled cationic lipophilic complexes in malignant and benign tumors: the role of SPET and pinhole-SPET in breast cancer, differentiated thyroid carcinoma and hyperparathyroidism

    International Nuclear Information System (INIS)

    Schillaci, O.; Spanu, A.; Madeddu, G.

    2005-01-01

    Single photon emission tomography (SPET) represents an indispensable diagnostic tool in nuclear medicine. Due to better contrast resolution, cross sectional and 3D images, SPET plays a useful complementary tool to bidimensional planar scintigraphy in certain clinical conditions, while representing the procedure of choice in others. However, high resolution SPET with pinhole collimator (P-SPET) can improve conventional SPET sensitivity with parallel hole collimators. This review summarized data on the employment of conventional SPET and P-SPET in breast cancer, differentiated thyroid cancer (DTC) and hyperparathyroidism patients, using the cationic lipophilic complexes ( 99m Tc )metoxy isobutyl isonitrile (sestaMIBI) and ( 99m Tc )tetrofosmin as oncotropic radiotracers. In breast cancer patients, SPET with these radiotracers can play an important complementary role to planar scintimammography in detecting primary tumors, especially when non palpable and small in size, whereas SPET and particularly P-SPET represents the procedure of choice in preoperative axillary lymph node status evaluation in which planar is almost always irrelevant. In DTC follow-up patients, SPET and P-SPET with cationic lipophilic radiotracers are indicated in both locoregional and distant metastasis detection, especially in patients with high Tg serum levels and negative radioiodine scanning in whom these procedures represent a reliable alternative to diagnostic 131 I scanning. Moreover, the combined use of ( 99m Tc)tetrofosmin P-SPET and US can identify recurrences and lymph node metastases in the neck, both fixing and non fixing iodine, down staged or negative at 131 I scanning. SPET can also be a useful complementary tool to planar parathyroid scintigraphy in the detection and localization of small and ectopic parathyroid adenomas in the neck or mediastinum, while neck P-SPET seems to also significantly increase planer sensitivity in hyperplastic glands. SPET and P-SPET are indicated in

  2. A novel data processing technique for image reconstruction of penumbral imaging

    Science.gov (United States)

    Xie, Hongwei; Li, Hongyun; Xu, Zeping; Song, Guzhou; Zhang, Faqiang; Zhou, Lin

    2011-06-01

    CT image reconstruction technique was applied to the data processing of the penumbral imaging. Compared with other traditional processing techniques for penumbral coded pinhole image such as Wiener, Lucy-Richardson and blind technique, this approach is brand new. In this method, the coded aperture processing method was used for the first time independent to the point spread function of the image diagnostic system. In this way, the technical obstacles was overcome in the traditional coded pinhole image processing caused by the uncertainty of point spread function of the image diagnostic system. Then based on the theoretical study, the simulation of penumbral imaging and image reconstruction was carried out to provide fairly good results. While in the visible light experiment, the point source of light was used to irradiate a 5mm×5mm object after diffuse scattering and volume scattering. The penumbral imaging was made with aperture size of ~20mm. Finally, the CT image reconstruction technique was used for image reconstruction to provide a fairly good reconstruction result.

  3. Image processing in digital chest radiography

    International Nuclear Information System (INIS)

    Manninen, H.; Partanen, K.; Lehtovirta, J.; Matsi, P.; Soimakallio, S.

    1992-01-01

    The usefulness of digital image processing of chest radiographs was evaluated in a clinical study. In 54 patients, chest radiographs in the posteroanterior projection were obtained by both 14 inch digital image intensifier equipment and the conventional screen-film technique. The digital radiographs (512x512 image format) viewed on a 625 line monitor were processed in 3 different ways: 1.standard display; 2.digital edge enhancement for the standard display; 3.inverse intensity display. The radiographs were interpreted independently by 3 radiologists. Diagnoses were confirmed by CT, follow-up radiographs and clinical records. Chest abnormalities of the films analyzed included 21 primary lung tumors, 44 pulmonary nodules, 16 cases with mediastinal disease, 17 with pneumonia /atelectasis. Interstitial lung disease, pleural plaques, and pulmonary emphysema were found in 30, 18 and 19 cases respectively. Sensitivity of conventional radiography when averaged overall findings was better than that of digital techniques (P<0.001). Differences in diagnostic accuracy measured by sensitivity and specificity between the 3 digital display modes were small. Standard image display showed better sensitivity for pulmonary nodules (0.74 vs 0.66; P<0.05) but poorer specificity for pulmonary emphysema (0.85 vs 0.93; P<0.05) compared with inverse intensity display. It is concluded that when using 512x512 image format, the routine use of digital edge enhancement and tone reversal at digital chest radiographs is not warranted. (author). 12 refs.; 4 figs.; 2 tabs

  4. Applied medical image processing a basic course

    CERN Document Server

    Birkfellner, Wolfgang

    2014-01-01

    A widely used, classroom-tested text, Applied Medical Image Processing: A Basic Course delivers an ideal introduction to image processing in medicine, emphasizing the clinical relevance and special requirements of the field. Avoiding excessive mathematical formalisms, the book presents key principles by implementing algorithms from scratch and using simple MATLAB®/Octave scripts with image data and illustrations on an accompanying CD-ROM or companion website. Organized as a complete textbook, it provides an overview of the physics of medical image processing and discusses image formats and data storage, intensity transforms, filtering of images and applications of the Fourier transform, three-dimensional spatial transforms, volume rendering, image registration, and tomographic reconstruction.

  5. Digital image processing and analysis human and computer vision applications with CVIPtools

    CERN Document Server

    Umbaugh, Scott E

    2010-01-01

    Section I Introduction to Digital Image Processing and AnalysisDigital Image Processing and AnalysisOverviewImage Analysis and Computer VisionImage Processing and Human VisionKey PointsExercisesReferencesFurther ReadingComputer Imaging SystemsImaging Systems OverviewImage Formation and SensingCVIPtools SoftwareImage RepresentationKey PointsExercisesSupplementary ExercisesReferencesFurther ReadingSection II Digital Image Analysis and Computer VisionIntroduction to Digital Image AnalysisIntroductionPreprocessingBinary Image AnalysisKey PointsExercisesSupplementary ExercisesReferencesFurther Read

  6. Optimization of pinhole single photon emission computed tomography (pinhole SPECT) reconstruction

    International Nuclear Information System (INIS)

    Israel-Jost, V.

    2006-11-01

    In SPECT small animal imaging, it is highly recommended to accurately model the response of the detector in order to improve the low spatial resolution. The volume to reconstruct is thus obtained both by back-projecting and de-convolving the projections. We chose iterative methods, which permit one to solve the inverse problem independently from the model's complexity. We describe in this work a Gaussian model of point spread function (PSF) whose position, width and maximum are computed according to physical and geometrical parameters. Then we use the rotation symmetry to replace the computation of P projection operators, each one corresponding to one position of the detector around the object, by the computation of only one of them. This is achieved by choosing an appropriate polar discretization, for which we control the angular density of voxels to avoid over-sampling the center of the field of view. Finally, we propose a new family of algorithms, the so-called frequency adapted algorithms, which enable to optimize the reconstruction of a given band in the frequency domain on both the speed of convergence and the quality of the image. (author)

  7. Defects quantization in industrial radiographs by image processing

    International Nuclear Information System (INIS)

    Briand, F.Y.; Brillault, B.; Philipp, S.

    1988-01-01

    This paper refers to the industrial application of image processing using Non Destructive Testing by radiography. The various problems involved by the conception of a numerical tool are described. This tool intends to help radiograph experts to quantify defects and to follow up their evolution, using numerical techniques. The sequences of processings that achieve defect segmentation and quantization are detailed. They are based on the thorough knowledge of radiographs formation techniques. The process uses various methods of image analysis, including textural analysis and morphological mathematics. The interface between the final product and users will occur in an explicit language, using the terms of radiographic expertise without showing any processing details. The problem is thoroughly described: image formation, digitization, processings fitted to flaw morphology and finally product structure in progress. 12 refs [fr

  8. Expedited, uniform processing of multi-vendor gamma test data

    International Nuclear Information System (INIS)

    Zimmerman, R.E.

    2002-01-01

    Aim: Acceptance testing of gamma camera performance is time consuming. When data is collected from different vendors image format and methodology differences can result in disjointed and difficult to compare results. Even when performing NEMA specified tests consistent processing of data from multi-vendor cameras results in methodological inconsistencies. A more uniform and consistent method to process data collected from gamma cameras would be a boon to those involved in acquiring and processing such test data. Methods and Materials: Image J is an image processing program freely available on the Web at http://rsb.info.nih.gov/ij/. It can be run using a normal Web browser or installed on any computer. Since it is written in Java it is platform and operating system independent. Image J is very extensible, object based and has a large international user community in many imaging disciplines. Extensions to Image J are written using the Java programming language and the internal macro recording facility. Image J handles multiple image formats useful in nuclear medicine including DICOM, RAW, BMP, JPG, Interfile, AVI and QT. Extensions have been written to process and determine gamma camera intrinsic and extrinsic uniformity, COR errors, planar extrinsic resolution and reconstructed spatial resolution. The testing and processing adhere closely to NEMA specified procedures and result in quantitative measures of performance traceable to NEMA and manufacturers specifications. Results and Conclusions: Extensions to Image J written specifically to process gamma camera acceptance test data have resulted in considerable decrease in time to complete the analysis and allows a consistent, vendor independent, method to measure performance of cameras from multiple vendors. Quality control images from multiple camera vendors are also easily processed in a consistent fashion. The availability of this or similar platform and vendor independent software should lead to more complete

  9. Experimental studies of the argon-puff Z-pinch implosion process

    International Nuclear Information System (INIS)

    Huang Xianbin; Yang Libing; Gu Yuanchao; Deng Jianjun; Zhou Rongguo; Zou Jie; Zhou Shaotong; Zhang Siqun; Chen Guanghua; Chang Lihua; Li Fengping; Ouyang Kai; Li Jun; Yang Liang; Wang Xiong; Zhang Zhaohui

    2006-01-01

    A preliminary experiment for studying the argon-puff Z-pinch implosion process has been performed on the Yang accelerator. The ten-frame nanosecond temporal and spatial gated camera, visible high-speed scanning camera, differential laser interferometer, X-ray time integration pinhole camera and X-ray power system have been used to investigated the evolution of the argon-puff Z-pinch. Some typical results of argon-puff Z-pinch during implosion and pinch phase, including the 'zipper' effect, necking phenomenon, sausage instability, temperature changes and the effect of load current rise time, are given and analyzed as examples, and some relevant conclusions are drawn. (authors)

  10. Automated processing for proton spectroscopic imaging using water reference deconvolution.

    Science.gov (United States)

    Maudsley, A A; Wu, Z; Meyerhoff, D J; Weiner, M W

    1994-06-01

    Automated formation of MR spectroscopic images (MRSI) is necessary before routine application of these methods is possible for in vivo studies; however, this task is complicated by the presence of spatially dependent instrumental distortions and the complex nature of the MR spectrum. A data processing method is presented for completely automated formation of in vivo proton spectroscopic images, and applied for analysis of human brain metabolites. This procedure uses the water reference deconvolution method (G. A. Morris, J. Magn. Reson. 80, 547(1988)) to correct for line shape distortions caused by instrumental and sample characteristics, followed by parametric spectral analysis. Results for automated image formation were found to compare favorably with operator dependent spectral integration methods. While the water reference deconvolution processing was found to provide good correction of spatially dependent resonance frequency shifts, it was found to be susceptible to errors for correction of line shape distortions. These occur due to differences between the water reference and the metabolite distributions.

  11. Image Formation in Second-Harmonic Near-Field Microscopy

    DEFF Research Database (Denmark)

    Bozhevolnyi, Sergey I.; Lozovski, Valeri Z.; Pedersen, Kjeld

    1999-01-01

    contributions in the effective current, i.e., the currents generated by the self-consistent fields at the fundamental and second-harmonic frequencies. The self-consistent problem for both frequencies is solved exactly by use of the diagram technique adapted from quantum electrodynamics. Preliminary numerical...

  12. Electroencephalograph (EEG) study on self-contemplating image formation

    Science.gov (United States)

    Meng, Qinglei; Hong, Elliot; Choa, Fow-Sen

    2016-05-01

    Electroencephalography (EEG) is one of the most widely used electrophysiological monitoring methods and plays a significant role in studies of human brain electrical activities. Default mode network (DMN), is a functional connection of brain regions that are activated while subjects are not in task positive state or not focused on the outside world. In this study, EEG was used for human brain signals recording while all subjects were asked to sit down quietly on a chair with eyes closed and thinking about some parts of their own body, such as left and right hands, left and right ears, lips, nose, and the images of faces that they were familiar with as well as doing some simple mathematical calculation. The time is marker when the image is formed in the subject's mind. By analyzing brain activity maps 300ms right before the time marked instant for each of the 4 wave bands, Delta, Theta, Alpha and Beta waves. We found that for most EEG datasets during this 300ms, Delta wave activity would mostly locate at the frontal lobe or the visual cortex, and the change and movement of activities are slow. Theta wave activity tended to rotate along the edge of cortex either clockwise or counterclockwise. Beta wave behaved like inquiry types of oscillations between any two regions spread over the cortex. Alpha wave activity looks like a mix of the Theta and Beta activities but more close to Theta activity. From the observation we feel that Beta and high Alpha are playing utility role for information inquiry. Theta and low Alpha are likely playing the role of binding and imagination formation in DMN operations.

  13. Image formation in track-etch detectors: Pt. 4

    International Nuclear Information System (INIS)

    Ilic, Radomir; Najzer, Mitja

    1990-01-01

    The radiographic performance of solid state nuclear track detectors was analysed with respect to image quality. Image quality is expressed in terms of three image quality factors: contrast or gradient of the detector, image unsharpness and detail discernment. Equations for the image quality factors were derived from the radiographic transfer function, taking into account image inhomogeneity caused by statistical fluctuations of track density. To find optimal radiographic conditions for a given application, a single quantity called the figure of radiographic merit was defined. It is expressed as the weighted product of the image quality factors. It was found that optimum image quality of a balanced image, characterized by equal importance of all three image quality factors, is obtained at an exposure value (defined as the product of the average visible track area and track density) of unity. (author)

  14. Optimal Local Dimming for LC Image Formation With Controllable Backlighting

    DEFF Research Database (Denmark)

    Shu, Xiao; Wu, Xiaolin; Forchhammer, Søren

    2013-01-01

    Light emitting diode (LED)-backlit liquid crystal displays (LCDs) hold the promise of improving image quality while reducing the energy consumption with signal-dependent local dimming. However, most existing local dimming algorithms are mostly motivated by simple implementation, and they often la...

  15. Transmission electron microscopy physics of image formation and microanalysis

    CERN Document Server

    Reimer, Ludwig

    1993-01-01

    "Transmission Electron Microscopy" presents the theory of image and contrastformation, and the analytical modes in transmission electron microscopy Theprinciples of particle and wave optics of electrons are described Electron-specimen interactions are discussed for evaluating the theory of scattering and phase contrast Also analysed are the kinetical and dynamical theories of electron diffraction and their applications for crystal-structure determination and imaging of lattices and their defects X-ray microanalysis and electron energy-loss spectroscopy are treated as analytical methods The third edition includes a brief discussionof Schottky emission guns, some clarification of minor details, and references to the recent literature

  16. Intermediate States and Powerful Ideas: Learning about Image Formation.

    Science.gov (United States)

    Goldberg, Fred; Bendall, Sharon

    This paper describes a curriculum unit developed in the domain of geometrical optics which has been incorporated into an activity-based physics course for prospective elementary teachers. The instructional goal was to help students develop a set of powerful ideas that could be applied both verbally and diagrammatically to account for optical…

  17. Modeling of Image Formation in Cryo-Electron Microscopy

    NARCIS (Netherlands)

    Vulovic, M.

    2013-01-01

    Knowledge of the structure of biological specimens is crucial for understanding life. Cryo-electron microscopy (cryo-EM) permits structural studies of biological specimen at their near-native state. The research performed in this thesis represents one of two subprojects of the FOM industrial

  18. Transmission electron microscopy physics of image formation and microanalysis

    CERN Document Server

    Reimer, Ludwig

    1997-01-01

    Transmission Electron Microscopy presents the theory of image and contrast formation, and the analytical modes in transmission electron microscopy. The principles of particle and wave optics of electrons are described. Electron-specimen interactions are discussed for evaluating the theory of scattering and phase contrast. Also discussed are the kinematical and dynamical theories of electron diffraction and their applications for crystal-structure analysis and imaging of lattices and their defects. X-ray micronanalysis and electron energy-loss spectroscopy are treated as analytical methods. Specimen damage and contamination by electron irradiation limits the resolution for biological and some inorganic specimens. This fourth edition includes discussion of recent progress, especially in the area of Schottky emission guns, convergent-beam electron diffraction, electron tomography, holography and the high resolution of crystal lattices.

  19. Morphology modification of perovskite film by a simple post-treatment process in perovskite solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Song, J.; Yang, Y.; Zhao, Y.L., E-mail: sdyulong@cumt.edu.cn; Che, M.; Zhu, L.; Gu, X.Q.; Qiang, Y.H., E-mail: yhqiang@cumt.edu.cn

    2017-03-15

    Highlights: • Perovskite films were post-treated by DMF/CBZ, DMSO/CBZ, or GBL/CBZ blend solvents. • This process could repair pinholes and enhance coverage in perovskite film. • This technique could modify charge transfer process at TiO{sub 2}/perovskite interface. - Abstract: A homogenous perovskite thin film with high coverage is a determining factor for high performance perovskite solar cells. Unlike previous pre-treatments aiming at perovskite precursor, we proposed a simple method to modify the morphology of perovskite films by post-treatment process using mixed solvents of N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), or 1,4-butyrolactone (GBL) with chlorobenzene (CBZ) in this paper. As good solvent of perovskite, DMF, DMSO, and GBL could dissolve the formed perovskite film. Meanwhile, CBZ, anti-solvent of perovskite film, could decrease the dissolving capacity of these good solvents. Therefore, the perovskite film coverage might be improved by the partial dissolution and recrystallization after solvent post-treatment process. Electrochemical impedance spectrometry (EIS) and time-resolved photoluminescence (TRPL) indicated that this post-treatment process could enhance charge transfer at TiO{sub 2}/perovskite interface. Finally, the conversion efficiency increased from 10.10% to 11.82%, 11.68%, and 10.66% using perovskite films post-treated by DMF/CBZ, DMSO/CBZ, and GBL/CBZ blend solvents, respectively.

  20. Fuel processing. Wastes processing

    International Nuclear Information System (INIS)

    Bourgeois, M.

    2000-01-01

    The gaseous, liquid and solid radioactive effluents generated by the fuel reprocessing, can't be release in the environment. They have to be treated in order to respect the limits of the pollution regulations. These processing are detailed and discussed in this technical paper. A second part is devoted to the SPIN research program relative to the separation of the long life radionuclides in order to reduce the radioactive wastes storage volume. (A.L.B.)

  1. Surface defect detection in tiling Industries using digital image processing methods: analysis and evaluation.

    Science.gov (United States)

    Karimi, Mohammad H; Asemani, Davud

    2014-05-01

    Ceramic and tile industries should indispensably include a grading stage to quantify the quality of products. Actually, human control systems are often used for grading purposes. An automatic grading system is essential to enhance the quality control and marketing of the products. Since there generally exist six different types of defects originating from various stages of tile manufacturing lines with distinct textures and morphologies, many image processing techniques have been proposed for defect detection. In this paper, a survey has been made on the pattern recognition and image processing algorithms which have been used to detect surface defects. Each method appears to be limited for detecting some subgroup of defects. The detection techniques may be divided into three main groups: statistical pattern recognition, feature vector extraction and texture/image classification. The methods such as wavelet transform, filtering, morphology and contourlet transform are more effective for pre-processing tasks. Others including statistical methods, neural networks and model-based algorithms can be applied to extract the surface defects. Although, statistical methods are often appropriate for identification of large defects such as Spots, but techniques such as wavelet processing provide an acceptable response for detection of small defects such as Pinhole. A thorough survey is made in this paper on the existing algorithms in each subgroup. Also, the evaluation parameters are discussed including supervised and unsupervised parameters. Using various performance parameters, different defect detection algorithms are compared and evaluated. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

  2. Pinhole Breaches in Spent Fuel Containers: Some Modeling Considerations

    International Nuclear Information System (INIS)

    Casella, Andrew M.; Loyalka, Sudarsham K.; Hanson, Brady D.

    2006-01-01

    This paper replaces PNNL-SA-48024 and incorporates the ANS reviewer's comments, including the change in the title. Numerical methods to solve the equations for gas diffusion through very small breaches in spent fuel containers are presented and compared with previous literature results

  3. Pseudo real-time imaging systems with nonredundant pinhole arrays

    International Nuclear Information System (INIS)

    Han, K.S.; Berzins, G.J.; Roach, W.H.

    1976-01-01

    Coded aperture techniques, because of their efficiency and three-dimensional information content, represent potentially powerful tools for LMFBR safety experiment diagnostics. These techniques should be even more powerful if the data can be interpreted in real time or in pseudo real time. For example, to satisfy the stated goals for LMFBR diagnostics (1-ms time resolution and 1-mm spatial resolution), it is conceivable that several hundred frames of coded data would be recorded. To unscramble all of this information into reconstructed images could be a laborious, time-consuming task. A way to circumvent the tedium is with the use of the described hybrid digital/analog real-time imaging system. Some intermediate results are described briefly

  4. Organic synthetic dye degradation by modified pinhole discharge

    Czech Academy of Sciences Publication Activity Database

    Božic' Lončaric', A.; Koprivanac, N.; Šunka, Pavel; Člupek, Martin; Babický, Václav

    2004-01-01

    Roč. 54, suppl.C (2004), C958-C963 ISSN 0011-4626. [Symposium on Plasma Physics and Technology /21st/. Praha, 14.06.2004-17.06.2004] R&D Projects: GA ČR GA202/02/1026 Keywords : organic synthetic Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.292, year: 2004

  5. Fast image processing on parallel hardware

    International Nuclear Information System (INIS)

    Bittner, U.

    1988-01-01

    Current digital imaging modalities in the medical field incorporate parallel hardware which is heavily used in the stage of image formation like the CT/MR image reconstruction or in the DSA real time subtraction. In order to image post-processing as efficient as image acquisition, new software approaches have to be found which take full advantage of the parallel hardware architecture. This paper describes the implementation of two-dimensional median filter which can serve as an example for the development of such an algorithm. The algorithm is analyzed by viewing it as a complete parallel sort of the k pixel values in the chosen window which leads to a generalization to rank order operators and other closely related filters reported in literature. A section about the theoretical base of the algorithm gives hints for how to characterize operations suitable for implementations on pipeline processors and the way to find the appropriate algorithms. Finally some results that computation time and usefulness of medial filtering in radiographic imaging are given

  6. Process Accounting

    OpenAIRE

    Gilbertson, Keith

    2002-01-01

    Standard utilities can help you collect and interpret your Linux system's process accounting data. Describes the uses of process accounting, standard process accounting commands, and example code that makes use of process accounting utilities.

  7. Effect of high-pressure food processing on the physical properties of synthetic and biopolymer films.

    Science.gov (United States)

    Galotto, M J; Ulloa, P A; Guarda, A; Gavara, R; Miltz, J

    2009-08-01

    The effect of high-pressure processing on 2 plastic food packaging films, a biopolymer (PLASiOx/PLA) and a synthetic polymer (PET-AlOx), was studied. Samples in direct contact with olive oil, as a fatty food simulant, and distilled water, as an aqueous simulant, were subjected to a pressure of 500MPa for 15 min at 50 degrees C. The mechanical, thermal, and gas barrier properties of both films were evaluated after the high-pressure processing (HPP) and compared to control samples that have not undergone this treatment. Significant changes in all properties were observed in both films after the HPP treatment and in contact with the food simulants. In both films an induced crystallization was noticed. In the PLASiOx/PLA film the changes were larger when in contact with water that probably acted as a plasticizer. In the PET-AlOx film the changes in properties were attributed to the formation of pinholes and cracks during the HPP treatment. In this film, most of the properties changed more in the presence of oil as the food simulant.

  8. Azimuth-Variant Signal Processing in High-Altitude Platform Passive SAR with Spaceborne/Airborne Transmitter

    Directory of Open Access Journals (Sweden)

    Huaizong Shao

    2013-03-01

    Full Text Available High-altitude platforms (HAP or near-space vehicle offers several advantages over current low earth orbit (LEO satellite and airplane, because HAP is not constrained by orbital mechanics and fuel consumption. These advantages provide potential for some specific remote sensing applications that require persistent monitoring or fast-revisiting frequency. This paper investigates the azimuth-variant signal processing in HAP-borne bistatic synthetic aperture radar (BiSAR with spaceborne or airborne transmitter for high-resolution remote sensing. The system configuration, azimuth-variant Doppler characteristics and two-dimensional echo spectrum are analyzed. Conceptual system simulation results are also provided. Since the azimuth-variant BiSAR geometry brings a challenge for developing high precision data processing algorithms, we propose an image formation algorithm using equivalent velocity and nonlinear chirp scaling (NCS to address the azimuth-variant signal processing problem. The proposed algorithm is verified by numerical simulation results.

  9. Meat Processing.

    Science.gov (United States)

    Legacy, Jim; And Others

    This publication provides an introduction to meat processing for adult students in vocational and technical education programs. Organized in four chapters, the booklet provides a brief overview of the meat processing industry and the techniques of meat processing and butchering. The first chapter introduces the meat processing industry and…

  10. Some computer applications and digital image processing in nuclear medicine

    International Nuclear Information System (INIS)

    Lowinger, T.

    1981-01-01

    Methods of digital image processing are applied to problems in nuclear medicine imaging. The symmetry properties of central nervous system lesions are exploited in an attempt to determine the three-dimensional radioisotope density distribution within the lesions. An algorithm developed by astronomers at the end of the 19th century to determine the distribution of matter in globular clusters is applied to tumors. This algorithm permits the emission-computed-tomographic reconstruction of spherical lesions from a single view. The three-dimensional radioisotope distribution derived by the application of the algorithm can be used to characterize the lesions. The applicability to nuclear medicine images of ten edge detection methods in general usage in digital image processing were evaluated. A general model of image formation by scintillation cameras is developed. The model assumes that objects to be imaged are composed of a finite set of points. The validity of the model has been verified by its ability to duplicate experimental results. Practical applications of this work involve quantitative assessment of the distribution of radipharmaceuticals under clinical situations and the study of image processing algorithms

  11. Process development

    Energy Technology Data Exchange (ETDEWEB)

    Schuegerl, K

    1984-01-01

    The item 'process development' comprises the production of acetonic/butonal with C. acetobylicum and the yeasting of potato waste. The target is to increase productivity by taking the following measures - optimation of media, on-line process analysis, analysis of reaction, mathematic modelling and identification of parameters, process simulation, development of a state estimator with the help of the on-line process analysis and the model, optimization and adaptive control.

  12. Poisson processes

    NARCIS (Netherlands)

    Boxma, O.J.; Yechiali, U.; Ruggeri, F.; Kenett, R.S.; Faltin, F.W.

    2007-01-01

    The Poisson process is a stochastic counting process that arises naturally in a large variety of daily life situations. We present a few definitions of the Poisson process and discuss several properties as well as relations to some well-known probability distributions. We further briefly discuss the

  13. Femtosecond Laser Processing of Membranes for Sensor Devices on different Bulk Materials

    Directory of Open Access Journals (Sweden)

    Johann Zehetner

    2017-01-01

    Full Text Available We demonstrate that diaphragms for sensor applications can be fabricated by laser ablation in a~variety of substrates such as ceramics, glass, sapphire or SiC. However, ablation can cause pinholes in membranes made of SiC, Si and metals. Our experiments indicate that pinhole defects in the ablated membranes are affected by ripple structures related to the polarization of the laser. From our simulation results on light propagation in Laser-Induced Periodic Surface Structures (LIPSS we find out that they are acting as a slot waveguide in SiC material. The results further show that field intensity is enhanced inside LIPSS and spreads out at surface distortions promoting the formation of pinholes. The membrane corner area is most vulnerable for pinhole formation. Pinholes funnel laser radiation into the bulk material causing structural damage and stress in the membrane. We show that a~polarization flipping technique inhibits the formation of pin holes caused by LIPSS.

  14. Data processing

    CERN Document Server

    Fry, T F

    2013-01-01

    Data Processing discusses the principles, practices, and associated tools in data processing. The book is comprised of 17 chapters that are organized into three parts. The first part covers the characteristics, systems, and methods of data processing. Part 2 deals with the data processing practice; this part discusses the data input, output, and storage. The last part discusses topics related to systems and software in data processing, which include checks and controls, computer language and programs, and program elements and structures. The text will be useful to practitioners of computer-rel

  15. Stochastic processes

    CERN Document Server

    Parzen, Emanuel

    1962-01-01

    Well-written and accessible, this classic introduction to stochastic processes and related mathematics is appropriate for advanced undergraduate students of mathematics with a knowledge of calculus and continuous probability theory. The treatment offers examples of the wide variety of empirical phenomena for which stochastic processes provide mathematical models, and it develops the methods of probability model-building.Chapter 1 presents precise definitions of the notions of a random variable and a stochastic process and introduces the Wiener and Poisson processes. Subsequent chapters examine

  16. Magnetics Processing

    Data.gov (United States)

    Federal Laboratory Consortium — The Magnetics Processing Lab equipped to perform testing of magnetometers, integrate them into aircraft systems, and perform data analysis, including noise reduction...

  17. Data processing

    International Nuclear Information System (INIS)

    Cousot, P.

    1988-01-01

    The 1988 progress report of the Data Processing laboratory (Polytechnic School, France), is presented. The laboratory research fields are: the semantics, the tests and the semantic analysis of the codes, the formal calculus, the software applications, the algorithms, the neuron networks and VLSI (Very Large Scale Integration). The investigations concerning the polynomial rings are performed by means of the standard basis approach. Among the research topics, the Pascal codes, the parallel processing, the combinatorial, statistical and asymptotic properties of the fundamental data processing tools, the signal processing and the pattern recognition. The published papers, the congress communications and the thesis are also included [fr

  18. Suppurative processes

    International Nuclear Information System (INIS)

    Vinner, M.G.

    1983-01-01

    Suppurative process in the case of bronchiectatic disease, abscess and gang rene of lungs, has been described. Characteristic signs of roentgenologic pictu re of the above-mentioned diseases are considered. It is shown,that in most cas es roentgenologic studies give a possibility to make a high-quality diagnosis of suppurative processes

  19. Design Processes

    DEFF Research Database (Denmark)

    Ovesen, Nis

    2009-01-01

    Inspiration for most research and optimisations on design processes still seem to focus within the narrow field of the traditional design practise. The focus in this study turns to associated businesses of the design professions in order to learn from their development processes. Through interviews...... and emerging production methods....

  20. Process development

    International Nuclear Information System (INIS)

    Zapata G, G.

    1989-01-01

    Process development: The paper describes the organization and laboratory facilities of the group working on radioactive ore processing studies. Contains a review of the carried research and the plans for the next future. A list of the published reports is also presented

  1. Sustainable processing

    DEFF Research Database (Denmark)

    Kristensen, Niels Heine

    2004-01-01

    Kristensen_NH and_Beck A: Sustainable processing. In Otto Schmid, Alexander Beck and Ursula Kretzschmar (Editors) (2004): Underlying Principles in Organic and "Low-Input Food" Processing - Literature Survey. Research Institute of Organic Agriculture FiBL, CH-5070 Frick, Switzerland. ISBN 3-906081-58-3...

  2. Food processing

    NARCIS (Netherlands)

    Teodorowicz, Malgorzata; Neerven, Van Joost; Savelkoul, Huub

    2017-01-01

    The majority of foods that are consumed in our developed society have been processed. Processing promotes a non-enzymatic reaction between proteins and sugars, the Maillard reaction (MR). Maillard reaction products (MRPs) contribute to the taste, smell and color of many food products, and thus

  3. Membrane processes

    Science.gov (United States)

    Staszak, Katarzyna

    2017-11-01

    The membrane processes have played important role in the industrial separation process. These technologies can be found in all industrial areas such as food, beverages, metallurgy, pulp and paper, textile, pharmaceutical, automotive, biotechnology and chemical industry, as well as in water treatment for domestic and industrial application. Although these processes are known since twentieth century, there are still many studies that focus on the testing of new membranes' materials and determining of conditions for optimal selectivity, i. e. the optimum transmembrane pressure (TMP) or permeate flux to minimize fouling. Moreover the researchers proposed some calculation methods to predict the membrane processes properties. In this article, the laboratory scale experiments of membrane separation techniques, as well their validation by calculation methods are presented. Because membrane is the "heart" of the process, experimental and computational methods for its characterization are also described.

  4. Process mining

    DEFF Research Database (Denmark)

    van der Aalst, W.M.P.; Rubin, V.; Verbeek, H.M.W.

    2010-01-01

    Process mining includes the automated discovery of processes from event logs. Based on observed events (e.g., activities being executed or messages being exchanged) a process model is constructed. One of the essential problems in process mining is that one cannot assume to have seen all possible...... behavior. At best, one has seen a representative subset. Therefore, classical synthesis techniques are not suitable as they aim at finding a model that is able to exactly reproduce the log. Existing process mining techniques try to avoid such “overfitting” by generalizing the model to allow for more...... support for it). None of the existing techniques enables the user to control the balance between “overfitting” and “underfitting”. To address this, we propose a two-step approach. First, using a configurable approach, a transition system is constructed. Then, using the “theory of regions”, the model...

  5. Partial processing

    International Nuclear Information System (INIS)

    1978-11-01

    This discussion paper considers the possibility of applying to the recycle of plutonium in thermal reactors a particular method of partial processing based on the PUREX process but named CIVEX to emphasise the differences. The CIVEX process is based primarily on the retention of short-lived fission products. The paper suggests: (1) the recycle of fission products with uranium and plutonium in thermal reactor fuel would be technically feasible; (2) it would, however, take ten years or more to develop the CIVEX process to the point where it could be launched on a commercial scale; (3) since the majority of spent fuel to be reprocessed this century will have been in storage for ten years or more, the recycling of short-lived fission products with the U-Pu would not provide an effective means of making refabrication fuel ''inaccessible'' because the radioactivity associated with the fission products would have decayed. There would therefore be no advantage in partial processing

  6. Process monitoring

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    Many of the measurements and observations made in a nuclear processing facility to monitor processes and product quality can also be used to monitor the location and movements of nuclear materials. In this session information is presented on how to use process monitoring data to enhance nuclear material control and accounting (MC and A). It will be seen that SNM losses can generally be detected with greater sensitivity and timeliness and point of loss localized more closely than by conventional MC and A systems if process monitoring data are applied. The purpose of this session is to enable the participants to: (1) identify process unit operations that could improve control units for monitoring SNM losses; (2) choose key measurement points and formulate a loss indicator for each control unit; and (3) describe how the sensitivities and timeliness of loss detection could be determined for each loss indicator

  7. Process automation

    International Nuclear Information System (INIS)

    Moser, D.R.

    1986-01-01

    Process automation technology has been pursued in the chemical processing industries and to a very limited extent in nuclear fuel reprocessing. Its effective use has been restricted in the past by the lack of diverse and reliable process instrumentation and the unavailability of sophisticated software designed for process control. The Integrated Equipment Test (IET) facility was developed by the Consolidated Fuel Reprocessing Program (CFRP) in part to demonstrate new concepts for control of advanced nuclear fuel reprocessing plants. A demonstration of fuel reprocessing equipment automation using advanced instrumentation and a modern, microprocessor-based control system is nearing completion in the facility. This facility provides for the synergistic testing of all chemical process features of a prototypical fuel reprocessing plant that can be attained with unirradiated uranium-bearing feed materials. The unique equipment and mission of the IET facility make it an ideal test bed for automation studies. This effort will provide for the demonstration of the plant automation concept and for the development of techniques for similar applications in a full-scale plant. A set of preliminary recommendations for implementing process automation has been compiled. Some of these concepts are not generally recognized or accepted. The automation work now under way in the IET facility should be useful to others in helping avoid costly mistakes because of the underutilization or misapplication of process automation. 6 figs

  8. Perceptual Processing Affects Conceptual Processing

    Science.gov (United States)

    van Dantzig, Saskia; Pecher, Diane; Zeelenberg, Rene; Barsalou, Lawrence W.

    2008-01-01

    According to the Perceptual Symbols Theory of cognition (Barsalou, 1999), modality-specific simulations underlie the representation of concepts. A strong prediction of this view is that perceptual processing affects conceptual processing. In this study, participants performed a perceptual detection task and a conceptual property-verification task…

  9. Sewer Processes

    DEFF Research Database (Denmark)

    Hvitved-Jacobsen, Thorkild; Vollertsen, Jes; Nielsen, Asbjørn Haaning

    Since the first edition was published over a decade ago, advancements have been made in the design, operation, and maintenance of sewer systems, and new problems have emerged. For example, sewer processes are now integrated in computer models, and simultaneously, odor and corrosion problems caused...... by hydrogen sulfide and other volatile organic compounds, as well as other potential health issues, have caused environmental concerns to rise. Reflecting the most current developments, Sewer Processes: Microbial and Chemical Process Engineering of Sewer Networks, Second Edition, offers the reader updated...... and valuable information on the sewer as a chemical and biological reactor. It focuses on how to predict critical impacts and control adverse effects. It also provides an integrated description of sewer processes in modeling terms. This second edition is full of illustrative examples and figures, includes...

  10. Electrochemical Processes

    DEFF Research Database (Denmark)

    Bech-Nielsen, Gregers

    1997-01-01

    The notes describe in detail primary and secondary galvanic cells, fuel cells, electrochemical synthesis and electroplating processes, corrosion: measurments, inhibitors, cathodic and anodic protection, details of metal dissolution reactions, Pourbaix diagrams and purification of waste water from...

  11. Dissolution processes

    International Nuclear Information System (INIS)

    Silver, G.L.

    1976-01-01

    This review contains more than 100 observations and 224 references on the dissolution phenomenon. The dissolution processes are grouped into three categories: methods of aqueous attack, fusion methods, and miscellaneous observations on phenomena related to dissolution problems

  12. Renewal processes

    CERN Document Server

    Mitov, Kosto V

    2014-01-01

    This monograph serves as an introductory text to classical renewal theory and some of its applications for graduate students and researchers in mathematics and probability theory. Renewal processes play an important part in modeling many phenomena in insurance, finance, queuing systems, inventory control and other areas. In this book, an overview of univariate renewal theory is given and renewal processes in the non-lattice and lattice case are discussed. A pre-requisite is a basic knowledge of probability theory.

  13. Room-Temperature and Solution-Processable Cu-Doped Nickel Oxide Nanoparticles for Efficient Hole-Transport Layers of Flexible Large-Area Perovskite Solar Cells.

    Science.gov (United States)

    He, Qiqi; Yao, Kai; Wang, Xiaofeng; Xia, Xuefeng; Leng, Shifeng; Li, Fan

    2017-12-06

    Flexible perovskite solar cells (PSCs) using plastic substrates have become one of the most attractive points in the field of thin-film solar cells. Low-temperature and solution-processable nanoparticles (NPs) enable the fabrication of semiconductor thin films in a simple and low-cost approach to function as charge-selective layers in flexible PSCs. Here, we synthesized phase-pure p-type Cu-doped NiO x NPs with good electrical properties, which can be processed to smooth, pinhole-free, and efficient hole transport layers (HTLs) with large-area uniformity over a wide range of film thickness using a room-temperature solution-processing technique. Such a high-quality inorganic HTL allows for the fabrication of flexible PSCs with an active area >1 cm 2 , which have a power conversion efficiency over 15.01% without hysteresis. Moreover, the Cu/NiO x NP-based flexible devices also demonstrate excellent air stability and mechanical stability compared to their counterpart fabricated on the pristine NiO x films. This work will contribute to the evolution of upscaling flexible PSCs with a simple fabrication process and high device performances.

  14. Simulation of the radiography formation process from CT patient volume

    Energy Technology Data Exchange (ETDEWEB)

    Bifulco, P; Cesarelli, M; Verso, E; Roccasalva Firenze, M; Sansone, M; Bracale, M [University of Naples, Federico II, Electronic Engineering Department, Bioengineering Unit, Via Claudio, 21 - 80125 Naples (Italy)

    1999-12-31

    The aim of this work is to develop an algorithm to simulate the radiographic image formation process using volumetric anatomical data of the patient, obtained from 3D diagnostic CT images. Many applications, including radiographic driven surgery, virtual reality in medicine and radiologist teaching and training, may take advantage of such technique. The designed algorithm has been developed to simulate a generic radiographic equipment, whatever oriented respect to the patient. The simulated radiography is obtained considering a discrete number of X-ray paths departing from the focus, passing through the patient volume and reaching the radiographic plane. To evaluate a generic pixel of the simulated radiography, the cumulative absorption along the corresponding X-ray is computed. To estimate X-ray absorption in a generic point of the patient volume, 3D interpolation of CT data has been adopted. The proposed technique is quite similar to those employed in Ray Tracing. A computer designed test volume has been used to assess the reliability of the radiography simulation algorithm as a measuring tool. From the errors analysis emerges that the accuracy achieved by the radiographic simulation algorithm is largely confined within the sampling step of the CT volume. (authors) 16 refs., 12 figs., 1 tabs.

  15. Simulation of the radiography formation process from CT patient volume

    International Nuclear Information System (INIS)

    Bifulco, P.; Cesarelli, M.; Verso, E.; Roccasalva Firenze, M.; Sansone, M.; Bracale, M.

    1998-01-01

    The aim of this work is to develop an algorithm to simulate the radiographic image formation process using volumetric anatomical data of the patient, obtained from 3D diagnostic CT images. Many applications, including radiographic driven surgery, virtual reality in medicine and radiologist teaching and training, may take advantage of such technique. The designed algorithm has been developed to simulate a generic radiographic equipment, whatever oriented respect to the patient. The simulated radiography is obtained considering a discrete number of X-ray paths departing from the focus, passing through the patient volume and reaching the radiographic plane. To evaluate a generic pixel of the simulated radiography, the cumulative absorption along the corresponding X-ray is computed. To estimate X-ray absorption in a generic point of the patient volume, 3D interpolation of CT data has been adopted. The proposed technique is quite similar to those employed in Ray Tracing. A computer designed test volume has been used to assess the reliability of the radiography simulation algorithm as a measuring tool. From the errors analysis emerges that the accuracy achieved by the radiographic simulation algorithm is largely confined within the sampling step of the CT volume. (authors)

  16. Fuel processing

    International Nuclear Information System (INIS)

    Allardice, R.H.

    1990-01-01

    The technical and economic viability of the fast breeder reactor as an electricity generating system depends not only upon the reactor performance but also on a capability to recycle plutonium efficiently, reliably and economically through the reactor and fuel cycle facilities. Thus the fuel cycle is an integral and essential part of the system. Fuel cycle research and development has focused on demonstrating that the challenging technical requirements of processing plutonium fuel could be met and that the sometimes conflicting requirements of the fuel developer, fuel fabricator and fuel reprocessor could be reconciled. Pilot plant operation and development and design studies have established both the technical and economic feasibility of the fuel cycle but scope for further improvement exists through process intensification and flowsheet optimization. These objectives and the increasing processing demands made by the continuing improvement to fuel design and irradiation performance provide an incentive for continuing fuel cycle development work. (author)

  17. Organizing Process

    DEFF Research Database (Denmark)

    Hull Kristensen, Peer; Bojesen, Anders

    This paper invites to discuss the processes of individualization and organizing being carried out under what we might see as an emerging regime of change. The underlying argumentation is that in certain processes of change, competence becomes questionable at all times. The hazy characteristics...... of this regime of change are pursued through a discussion of competencies as opposed to qualifications illustrated by distinct cases from the Danish public sector in the search for repetitive mechanisms. The cases are put into a general perspective by drawing upon experiences from similar change processes...... in MNCs. The paper concludes by asking whether we can escape from a regime of competence in a world defined by a rhetoric of change and create a more promising world in which doubt and search serve as a strategy for gaining knowledge and professionalism that improve on our capability for mutualism....

  18. Welding process

    International Nuclear Information System (INIS)

    Abdul Nassir Ibrahim; Azali Muhammad; Ab. Razak Hamzah; Abd. Aziz Mohamed; Mohamad Pauzi Ismail

    2008-01-01

    For the final chapter of this book, there is basic introduction on welding process. The good radiography must know somehow on welding process so that they can know what kind of welding that must rejected or not. All of the exposure technique that mention in earlier chapter almost applicable in this field because welding process is critical problem if there is no inspection will be done. So, for this chapter, all the discontinuity that usually appeared will be discussed and there is another discontinuity maybe not to important and do not give big impact if found it, do not described here. On top of that, the decision to accept or reject based on code, standard and specification that agreed by both to make sure that decision that agreed is corrected and more meaningful.

  19. Markov Processes in Image Processing

    Science.gov (United States)

    Petrov, E. P.; Kharina, N. L.

    2018-05-01

    Digital images are used as an information carrier in different sciences and technologies. The aspiration to increase the number of bits in the image pixels for the purpose of obtaining more information is observed. In the paper, some methods of compression and contour detection on the basis of two-dimensional Markov chain are offered. Increasing the number of bits on the image pixels will allow one to allocate fine object details more precisely, but it significantly complicates image processing. The methods of image processing do not concede by the efficiency to well-known analogues, but surpass them in processing speed. An image is separated into binary images, and processing is carried out in parallel with each without an increase in speed, when increasing the number of bits on the image pixels. One more advantage of methods is the low consumption of energy resources. Only logical procedures are used and there are no computing operations. The methods can be useful in processing images of any class and assignment in processing systems with a limited time and energy resources.

  20. Film processing

    International Nuclear Information System (INIS)

    Abdul Nassir Ibrahim; Azali Muhammad; Ab. Razak Hamzah; Abd. Aziz Mohamed; Mohamad Pauzi Ismail

    2008-01-01

    The processing was made not only to show what are in the film but also to produce radiograph with high quality where the information gathered really presented level of the quality of the object inspected. Besides that, good procedure will make the film with good quality can keep the film in long time for reference. Here, more detailed on how the dark room functioned and its design. So, the good procedure while processed the film will be discussed detailed in this chapter from entering the dark room to exit from there.

  1. Extraction process

    International Nuclear Information System (INIS)

    Rendall, J.S.; Cahalan, M.J.

    1979-01-01

    A process is described for extracting at least two desired constituents from a mineral, using a liquid reagent which produces the constituents, or compounds thereof, in separable form and independently extracting those constituents, or compounds. The process is especially valuable for the extraction of phosphoric acid and metal values from acidulated phosphate rock, the slurry being contacted with selective extractants for phosphoric acid and metal (e.g. uranium) values. In an example, uranium values are oxidized to uranyl form and extracted using an ion exchange resin. (U.K.)

  2. Process simulation

    International Nuclear Information System (INIS)

    Cao, E.G.; Suarez, P.S.; Pantaleon, J.C.

    1984-01-01

    The search for an optimal design of a heavy water plant is done by means of a simulation model for the mass and enthalpy balances of the SH 2 -H 2 O exchange process. A symplified model for the simulation diagram where the entire plant is represented by a sole tray tower with recicles, and heat and mass feeds/extractions was used. The tower is simulated by the method developed by Tomich with the convergence part given by the algorithm of Broyden. The concluding part of the work is centered in setting the design parameters (flowrates, heat exchange rates, number of plates) wich give the desired process operating conditions. (author) [es

  3. Processing Proteases

    DEFF Research Database (Denmark)

    Ødum, Anders Sebastian Rosenkrans

    -terminal of the scissile bond, leaving C-terminal fusions to have non-native C-termini after processing. A solution yielding native C-termini would allow novel expression and purification systems for therapeutic proteins and peptides.The peptidyl-Lys metallopeptidase (LysN) of the fungus Armillaria mellea (Am) is one...... of few known proteases to have substrate specificity for the C-terminal side of the scissile bond. LysN exhibits specificity for lysine, and has primarily been used to complement trypsin in to proteomic studies. A working hypothesis during this study was the potential of LysN as a processing protease...

  4. Processing Branches

    DEFF Research Database (Denmark)

    Schindler, Christoph; Tamke, Martin; Tabatabai, Ali

    2014-01-01

    Angled and forked wood – a desired material until 19th century, was swept away by industrialization and its standardization of processes and materials. Contemporary information technology has the potential for the capturing and recognition of individual geometries through laser scanning...

  5. BENTONITE PROCESSING

    Directory of Open Access Journals (Sweden)

    Anamarija Kutlić

    2012-07-01

    Full Text Available Bentonite has vide variety of uses. Special use of bentonite, where its absorbing properties are employed to provide water-tight sealing is for an underground repository in granites In this paper, bentonite processing and beneficiation are described.

  6. Purex process

    International Nuclear Information System (INIS)

    Starks, J.B.

    1977-01-01

    The following aspects of the Purex Process are discussed: head end dissolution, first solvent extraction cycle, second plutonium solvent extraction cycle, second uranium solvent extraction cycle, solvent recovery systems, primary recovery column for high activity waste, low activity waste, laboratory waste evaporation, vessel vent system, airflow and filtration, acid recovery unit, fume recovery, and discharges to seepage basin

  7. Innovation process

    DEFF Research Database (Denmark)

    Kolodovski, A.

    2006-01-01

    Purpose of this report: This report was prepared for RISO team involved in design of the innovation system Report provides innovation methodology to establish common understanding of the process concepts and related terminology The report does not includeRISO- or Denmark-specific cultural, econom...

  8. Processing Determinism

    Science.gov (United States)

    O'Grady, William

    2015-01-01

    I propose that the course of development in first and second language acquisition is shaped by two types of processing pressures--internal efficiency-related factors relevant to easing the burden on working memory and external input-related factors such as frequency of occurrence. In an attempt to document the role of internal factors, I consider…

  9. Shale processing

    Energy Technology Data Exchange (ETDEWEB)

    Hampton, W H

    1928-05-29

    The process of treating bituminiferous solid materials such as shale or the like to obtain valuable products therefrom, which comprises digesting a mixture of such material in comminuted condition with a suitable digestion liquid, such as an oil, recovering products vaporized in the digestion, and separating residual solid matter from the digestion liquid by centrifuging.

  10. Radiation processing

    International Nuclear Information System (INIS)

    Noriah Mod Ali

    2005-01-01

    This chapter covers the basic principle and application of radiation technology. The topic titled specific application discussed briefly the following subtopics: 1) Polymer modification - crosslinking, polymerisation, degradation, grafting; 2) Medical sterilisation; 3) Food irradiation; 4) Environmental protection - waste processing, pollutants treatment

  11. Leaching process

    International Nuclear Information System (INIS)

    Heinen, H.J.; McClelland, G.E.; Lindstrom, R.E.

    1982-01-01

    A gold and uranium ore is heap leached in accordance with the process comprising initial agglomeration of fines in the feed by means of a binding agent and cyanide solution. The lixiviant comprises a compatible mixture of sodium cyanide and sodium bicarbonate

  12. Leaching process

    Energy Technology Data Exchange (ETDEWEB)

    Heinen, H J; McClelland, G E; Lindstrom, R E

    1982-10-18

    A gold and uranium ore is heap leached in accordance with the process comprising initial agglomeration of fines in the feed by means of a binding agent and cyanide solution. The lixiviant comprises a compatible mixture of sodium cyanide and sodium bicarbonate.

  13. Signal Processing

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Signal processing techniques, extensively used nowadays to maximize the performance of audio and video equipment, have been a key part in the design of hardware and software for high energy physics detectors since pioneering applications in the UA1 experiment at CERN in 1979

  14. Process validation for radiation processing

    International Nuclear Information System (INIS)

    Miller, A.

    1999-01-01

    Process validation concerns the establishment of the irradiation conditions that will lead to the desired changes of the irradiated product. Process validation therefore establishes the link between absorbed dose and the characteristics of the product, such as degree of crosslinking in a polyethylene tube, prolongation of shelf life of a food product, or degree of sterility of the medical device. Detailed international standards are written for the documentation of radiation sterilization, such as EN 552 and ISO 11137, and the steps of process validation that are described in these standards are discussed in this paper. They include material testing for the documentation of the correct functioning of the product, microbiological testing for selection of the minimum required dose and dose mapping for documentation of attainment of the required dose in all parts of the product. The process validation must be maintained by reviews and repeated measurements as necessary. This paper presents recommendations and guidance for the execution of these components of process validation. (author)

  15. A New Tool for Intelligent Parallel Processing of Radar/SAR Remotely Sensed Imagery

    Directory of Open Access Journals (Sweden)

    A. Castillo Atoche

    2013-01-01

    Full Text Available A novel parallel tool for large-scale image enhancement/reconstruction and postprocessing of radar/SAR sensor systems is addressed. The proposed parallel tool performs the following intelligent processing steps: image formation, for the application of different system-level effects of image degradation with a particular remote sensing (RS system and simulation of random noising effects, enhancement/reconstruction by employing nonparametric robust high-resolution techniques, and image postprocessing using the fuzzy anisotropic diffusion technique which incorporates a better edge-preserving noise removal effect and faster diffusion process. This innovative tool allows the processing of high-resolution images provided with different radar/SAR sensor systems as required by RS endusers for environmental monitoring, risk prevention, and resource management. To verify the performance implementation of the proposed parallel framework, the processing steps are developed and specifically tested on graphic processing units (GPU, achieving considerable speedups compared to the serial version of the same techniques implemented in C language.

  16. Improved Morphology and Efficiency of n-i-p Planar Perovskite Solar Cells by Processing with Glycol Ether Additives

    KAUST Repository

    Ugur, Esma

    2017-07-31

    Planar perovskite solar cells can be prepared without high temperature processing steps typically associated with mesoporous device architectures; however, their efficiency has been lower and producing high quality perovskite films in planar devices has been challenging. Here, we report a modified two-step interdiffusion protocol suitable to prepare pin-hole free perovskite films with greatly improved morphology. This is achieved by simple addition of small amounts of glycol ethers to the preparation protocol. We unravel the impact the glycol ethers have on the perovskite film formation using in-situ UV-Vis absorbance and GIWAXS experiments. From these experiments we conclude: addition of glycol ethers changes the lead iodide to perovskite conversion dynamics and enhances the conversion efficiency, resulting in more compact polycrystalline films, and it creates micrometer-sized perovskite crystals vertically-aligned across the photoactive layer. Consequently, the average photovoltaic performance increases from 13.5% to 15.9% and reproduciability is enhanced, specifically when 2-methoxyethanol is used as additive.

  17. Improved Morphology and Efficiency of n-i-p Planar Perovskite Solar Cells by Processing with Glycol Ether Additives

    KAUST Repository

    Ugur, Esma; Sheikh, Arif D.; Munir, Rahim; Khan, Jafar Iqbal; Barrit, Dounya; Amassian, Aram; Laquai, Fré dé ric

    2017-01-01

    Planar perovskite solar cells can be prepared without high temperature processing steps typically associated with mesoporous device architectures; however, their efficiency has been lower and producing high quality perovskite films in planar devices has been challenging. Here, we report a modified two-step interdiffusion protocol suitable to prepare pin-hole free perovskite films with greatly improved morphology. This is achieved by simple addition of small amounts of glycol ethers to the preparation protocol. We unravel the impact the glycol ethers have on the perovskite film formation using in-situ UV-Vis absorbance and GIWAXS experiments. From these experiments we conclude: addition of glycol ethers changes the lead iodide to perovskite conversion dynamics and enhances the conversion efficiency, resulting in more compact polycrystalline films, and it creates micrometer-sized perovskite crystals vertically-aligned across the photoactive layer. Consequently, the average photovoltaic performance increases from 13.5% to 15.9% and reproduciability is enhanced, specifically when 2-methoxyethanol is used as additive.

  18. Image processing techniques to evaluate mammography screening quality; Tecnicas de processamento de imagem para avaliar a qualidade de exames de mamografia

    Energy Technology Data Exchange (ETDEWEB)

    Quintana, Clara; Tirao, German [Consejo Nacional de Investigaciones Cientificas y Tecnicas, Buenos Aires (Argentina); Valente, Mauro [Universidad Nacional de Cordoba (Argentina). Facultad de Matematica, Astronomia y Fisica

    2011-07-01

    Mammography imaging has proved to be the best noninvasive method for breast cancer diagnosis, but it requires that irradiation parameters are set within Protocols recommendations (minimal dose delivering). This work presents an investigation on mammography image formation by means of validated Monte Carlo simulations along with further image analysis and mathematical processing. Several image processing methods have been suitably introduced and investigated according to their capability for micro-calcification detection and quality evaluation. The obtained results suggest the feasibility of all the proposed methods. Furthermore, it was possible to characterize the reliability of each and to infer the corresponding advantages or disadvantages, obtaining an image quality evaluation as a function of several parameters configurations. (author)

  19. Stochastic processes

    CERN Document Server

    Borodin, Andrei N

    2017-01-01

    This book provides a rigorous yet accessible introduction to the theory of stochastic processes. A significant part of the book is devoted to the classic theory of stochastic processes. In turn, it also presents proofs of well-known results, sometimes together with new approaches. Moreover, the book explores topics not previously covered elsewhere, such as distributions of functionals of diffusions stopped at different random times, the Brownian local time, diffusions with jumps, and an invariance principle for random walks and local times. Supported by carefully selected material, the book showcases a wealth of examples that demonstrate how to solve concrete problems by applying theoretical results. It addresses a broad range of applications, focusing on concrete computational techniques rather than on abstract theory. The content presented here is largely self-contained, making it suitable for researchers and graduate students alike.

  20. Offshoring Process

    DEFF Research Database (Denmark)

    Slepniov, Dmitrij; Sørensen, Brian Vejrum; Katayama, Hiroshi

    2011-01-01

    The purpose of this chapter is to contribute to the knowledge on how production offshoring and international operations management vary across cultural contexts. The chapter attempts to shed light on how companies approach the process of offshoring in different cultural contexts. In order...... of globalisation. Yet there are clear differences in how offshoring is conducted in Denmark and Japan. The main differences are outlined in a framework and explained employing cultural variables. The findings lead to a number of propositions suggesting that the process of offshoring is not simply a uniform...... technical-rational calculation of the most efficient organisation of activities across national borders, but it is rather specific to the parent companies’ national contexts....

  1. Photobiomodulation Process

    Directory of Open Access Journals (Sweden)

    Yang-Yi Xu

    2012-01-01

    Full Text Available Photobiomodulation (PBM is a modulation of laser irradiation or monochromatic light (LI on biosystems. There is little research on PBM dynamics although its phenomena and mechanism have been widely studied. The PBM was discussed from dynamic viewpoint in this paper. It was found that the primary process of cellular PBM might be the key process of cellular PBM so that the transition rate of cellular molecules can be extended to discuss the dose relationship of PBM. There may be a dose zone in which low intensity LI (LIL at different doses has biological effects similar to each other, so that biological information model of PBM might hold. LIL may self-adaptively modulate a chronic stress until it becomes successful.

  2. Multiphoton processes

    International Nuclear Information System (INIS)

    Manus, C.; Mainfray, G.

    1980-01-01

    The main features of multiphoton processes are described on a somewhat elementary basis. The emphasis is put on multiphoton ionization of atoms where the influence of resonance effects is given through typical examples. The important role played by the coherence of light is shown to produce a very dramatic influence on multiphoton absorption. Different observations concerning molecules, electrons, as well as solid surfaces illustrate the generality of these very non linear interaction between light and matter

  3. Process heat. Triggering the processes

    Energy Technology Data Exchange (ETDEWEB)

    Augsten, Eva

    2012-07-01

    If solar process heat is to find a market, then the decision makers in industrial companies need to be aware that it actually exists. This was one of the main goals of the So-Pro project, which officially drew to a close in April 2012. (orig.)

  4. Electrochromic Windows: Process and Fabrication Improvements for Lower Total Costs

    Energy Technology Data Exchange (ETDEWEB)

    Mark Burdis; Neil Sbar

    2007-03-31

    The overall goal with respect to the U.S. Department of Energy (DOE) is to achieve significant national energy savings through maximized penetration of EC windows into existing markets so that the largest cumulative energy reduction can be realized. The speed with which EC windows can be introduced and replace current IGU's (and current glazings) is clearly a strong function of cost. Therefore, the aim of this project was to investigate possible improvements to the SageGlass{reg_sign} EC glazing products to facilitate both process and fabrication improvements resulting in lower overall costs. The project was split into four major areas dealing with improvements to the electrochromic layer, the capping layer, defect elimination and general product improvements. Significant advancements have been made in each of the four areas. These can be summarized as follows: (1) Plasma assisted deposition for the electrochromic layer was pursued, and several improvements made to the technology for producing a plasma beam were made. Functional EC devices were produced using the new technology, but there are still questions to be answered regarding the intrinsic properties of the electrochromic films produced by this method. (2) The capping layer work was successfully implemented into the existing SageGlass{reg_sign} product, thereby providing a higher level of transparency and somewhat lower reflectivity than the 'standard' product. (3) Defect elimination is an ongoing effort, but this project spurred some major defect reduction programs, which led to significant improvements in yield, with all the implicit benefits afforded. In particular, major advances were made in the development of a new bus bar application process aimed at reducing the numbers of 'shorts' developed in the finished product, as well as making dramatic improvements in the methods used for tempering the glass, which had previously been seen to produce a defect which appeared as a

  5. Speech Processing.

    Science.gov (United States)

    1983-05-01

    The VDE system developed had the capability of recognizing up to 248 separate words in syntactic structures. 4 The two systems described are isolated...AND SPEAKER RECOGNITION by M.J.Hunt 5 ASSESSMENT OF SPEECH SYSTEMS ’ ..- * . by R.K.Moore 6 A SURVEY OF CURRENT EQUIPMENT AND RESEARCH’ by J.S.Bridle...TECHNOLOGY IN NAVY TRAINING SYSTEMS by R.Breaux, M.Blind and R.Lynchard 10 9 I-I GENERAL REVIEW OF MILITARY APPLICATIONS OF VOICE PROCESSING DR. BRUNO

  6. Markov processes

    CERN Document Server

    Kirkwood, James R

    2015-01-01

    Review of ProbabilityShort HistoryReview of Basic Probability DefinitionsSome Common Probability DistributionsProperties of a Probability DistributionProperties of the Expected ValueExpected Value of a Random Variable with Common DistributionsGenerating FunctionsMoment Generating FunctionsExercisesDiscrete-Time, Finite-State Markov ChainsIntroductionNotationTransition MatricesDirected Graphs: Examples of Markov ChainsRandom Walk with Reflecting BoundariesGambler’s RuinEhrenfest ModelCentral Problem of Markov ChainsCondition to Ensure a Unique Equilibrium StateFinding the Equilibrium StateTransient and Recurrent StatesIndicator FunctionsPerron-Frobenius TheoremAbsorbing Markov ChainsMean First Passage TimeMean Recurrence Time and the Equilibrium StateFundamental Matrix for Regular Markov ChainsDividing a Markov Chain into Equivalence ClassesPeriodic Markov ChainsReducible Markov ChainsSummaryExercisesDiscrete-Time, Infinite-State Markov ChainsRenewal ProcessesDelayed Renewal ProcessesEquilibrium State f...

  7. Coking processes

    Energy Technology Data Exchange (ETDEWEB)

    Hiller, H K

    1917-11-20

    A gas suitable for use in containers or motor-vehicles, etc., and consisting mainly of methane, is obtained by distilling at a temperature not exceeding 500/sup 0/C bastard cannel coal, lignite, wood, peat, shale, etc., in an horizontal or vertical retort, through which the material is continuously fed in a thin layer or column by means of a screw conveyor or the like. Cracking or dissociation of the gaseous products is prevented by introducing into the retort part of the gas which is the result of the process and which is compressed to a pressure of at least 15 atmospheres and allowed to expand into the retort to cool and carry away the gaseous products produced. These are then passed through condensers for extracting liquid hydrocarbons, and other hydrocarbons are extracted by passage through washing-oils. The gas is then compressed by a water-cooled pump to a pressure of 15 atmospheres, whereby a spirit similar to petrol is formed, and a stable gas left which is mainly methane, part of the gas being used to carry out the process described above.

  8. Etherification process

    Science.gov (United States)

    Smith, L.A. Jr.; Hearn, D.; Jones, E.M. Jr.

    1990-08-21

    A liquid phase process is described for oligomerization of C[sub 4] and C[sub 5] isoolefins or the etherification thereof with C[sub 1] to C[sub 6] alcohols wherein the reactants are contacted in a reactor with a fixed bed acid cation exchange resin catalyst at an LHSV of 5 to 20, pressure of 0 to 400 psig and temperature of 120 to 300 F wherein the improvement is the operation of the reactor at a pressure to maintain the reaction mixture at its boiling point whereby at least a portion but less than all of the reaction mixture is vaporized. By operating at the boiling point and allowing a portion of the reaction mixture to vaporize, the exothermic heat of reaction is dissipated by the formation of more boil up and the temperature in the reactor is controlled. 2 figs.

  9. Oligomerization process

    Science.gov (United States)

    Smith, L.A. Jr.; Hearn, D.; Jones, E.M. Jr.

    1991-03-26

    A liquid phase process is described for oligomerization of C[sub 4] and C[sub 5] isoolefins or the etherification thereof with C[sub 1] to C[sub 6] alcohols wherein the reactants are contacted in a reactor with a fixed bed acid cation exchange resin catalyst at an LHSV of 5 to 20, pressure of 0 to 400 psig and temperature of 120 to 300 F wherein the improvement is the operation of the reactor at a pressure to maintain the reaction mixture at its boiling point whereby at least a portion but less than all of the reaction mixture is vaporized. By operating at the boiling point and allowing a portion of the reaction mixture to vaporize, the exothermic heat of reaction is dissipated by the formation of more boil up and the temperature in the reactor is controlled. 2 figures.

  10. Lithospheric processes

    Energy Technology Data Exchange (ETDEWEB)

    Baldridge, W. [and others

    2000-12-01

    The authors used geophysical, geochemical, and numerical modeling to study selected problems related to Earth's lithosphere. We interpreted seismic waves to better characterize the thickness and properties of the crust and lithosphere. In the southwestern US and Tien Shari, crust of high elevation is dynamically supported above buoyant mantle. In California, mineral fabric in the mantle correlate with regional strain history. Although plumes of buoyant mantle may explain surface deformation and magmatism, our geochemical work does not support this mechanism for Iberia. Generation and ascent of magmas remains puzzling. Our work in Hawaii constrains the residence of magma beneath Hualalai to be a few hundred to about 1000 years. In the crust, heat drives fluid and mass transport. Numerical modeling yielded robust and accurate predictions of these processes. This work is important fundamental science, and applies to mitigation of volcanic and earthquake hazards, Test Ban Treaties, nuclear waste storage, environmental remediation, and hydrothermal energy.

  11. Lithospheric processes

    International Nuclear Information System (INIS)

    Baldridge, W.S.

    2000-01-01

    The authors used geophysical, geochemical, and numerical modeling to study selected problems related to Earth's lithosphere. We interpreted seismic waves to better characterize the thickness and properties of the crust and lithosphere. In the southwestern US and Tien Shari, crust of high elevation is dynamically supported above buoyant mantle. In California, mineral fabric in the mantle correlate with regional strain history. Although plumes of buoyant mantle may explain surface deformation and magmatism, our geochemical work does not support this mechanism for Iberia. Generation and ascent of magmas remains puzzling. Our work in Hawaii constrains the residence of magma beneath Hualalai to be a few hundred to about 1000 years. In the crust, heat drives fluid and mass transport. Numerical modeling yielded robust and accurate predictions of these processes. This work is important fundamental science, and applies to mitigation of volcanic and earthquake hazards, Test Ban Treaties, nuclear waste storage, environmental remediation, and hydrothermal energy

  12. Carbonizing process

    Energy Technology Data Exchange (ETDEWEB)

    1923-11-22

    In the downward distillation of coal, shale, lignite, or the like, the heat is generated by the combustion of liquid or gaseous fuel above the charge the zone of carbonization thus initiated travelling downwards through the charge. The combustible gases employed are preferably those resulting from the process but gases such as natural gas may be employed. The charge is in a moistened and pervious state the lower parts being maintained at a temperature not above 212/sup 0/F until influenced by contact with the carbonization zone and steam may be admitted to increase the yield of ammonia. The combustible gases may be supplied with insufficient air so as to impart to them a reducing effect.

  13. WELDING PROCESS

    Science.gov (United States)

    Zambrow, J.; Hausner, H.

    1957-09-24

    A method of joining metal parts for the preparation of relatively long, thin fuel element cores of uranium or alloys thereof for nuclear reactors is described. The process includes the steps of cleaning the surfaces to be jointed, placing the sunfaces together, and providing between and in contact with them, a layer of a compound in finely divided form that is decomposable to metal by heat. The fuel element members are then heated at the contact zone and maintained under pressure during the heating to decompose the compound to metal and sinter the members and reduced metal together producing a weld. The preferred class of decomposable compounds are the metal hydrides such as uranium hydride, which release hydrogen thus providing a reducing atmosphere in the vicinity of the welding operation.

  14. Processing Disability.

    Science.gov (United States)

    Harris, Jasmine

    2015-01-01

    This Article argues that the practice of holding so many adjudicative proceedings related to disability in private settings (e.g., guardianship, special education due process, civil commitment, and social security) relative to our strong normative presumption of public access to adjudication may cultivate and perpetuate stigma in contravention of the goals of inclusion and enhanced agency set forth in antidiscrimination laws. Descriptively, the law has a complicated history with disability--initially rendering disability invisible; later, underwriting particular narratives of disability synonymous with incapacity; and, in recent history, promoting the full socio-economic visibility of people with disabilities. The Americans with Disabilities Act (ADA), the marquee civil rights legislation for people with disabilities (about to enter its twenty-fifth year), expresses a national approach to disability that recognizes the role of society in its construction, maintenance, and potential remedy. However, the ADA’s mission is incomplete. It has not generated the types of interactions between people with disabilities and nondisabled people empirically shown to deconstruct deeply entrenched social stigma. Prescriptively, procedural design can act as an "ntistigma agent"to resist and mitigate disability stigma. This Article focuses on one element of institutional design--public access to adjudication--as a potential tool to construct and disseminate counter-narratives of disability. The unique substantive focus in disability adjudication on questions of agency provides a potential public space for the negotiation of nuanced definitions of disability and capacity more reflective of the human condition.

  15. [In process.

    Science.gov (United States)

    Kaasch, Michael; Kaasch, Joachim

    -increasing competitiveness which came to a head as an embroiled dispute resulting from differences in scientific and scientific policy views. In the process a battle was fought over research resources so that, what was at first an apparently personal quarrel, affected the course of research promotion at an institutional level in the area of life sciences in the GDR. Despite several attempts at mediation, old age finally forced the adversaries to put aside their differences.

  16. Data Processing

    Science.gov (United States)

    Grangeat, P.

    A new area of biology has been opened up by nanoscale exploration of the living world. This has been made possible by technological progress, which has provided the tools needed to make devices that can measure things on such length and time scales. In a sense, this is a new window upon the living world, so rich and so diverse. Many of the investigative methods described in this book seek to obtain complementary physical, chemical, and biological data to understand the way it works and the way it is organised. At these length and time scales, only dedicated instrumentation could apprehend the relevant phenomena. There is no way for our senses to observe these things directly. One important field of application is molecular medicine, which aims to explain the mechanisms of life and disease by the presence and quantification of specific molecular entities. This involves combining information about genes, proteins, cells, and organs. This in turn requires the association of instruments for molecular diagnosis, either in vitro, e.g., the microarray or the lab-on-a-chip, or in vivo, e.g., probes for molecular biopsy, and tools for molecular imaging, used to localise molecular information in living organisms in a non-invasive way. These considerations concern both preclinical research for drug design and human medical applications. With the development of DNA and RNA chips [1], genomics has revolutionised investigative methods for cells and cell processes [2,3]. By sequencing the human genome, new ways have been found for understanding the fundamental mechanisms of life [4]. A revolution is currently under way with the analysis of the proteome [5-8], i.e., the complete set of proteins that can be found in some given biological medium, such as the blood plasma. The goal is to characterise certain diseases by recognisable signatures in the proteomic profile, as determined from a blood sample or a biopsy, for example [9-13]. What is at stake is the early detection of

  17. Solution-processable MoOx nanocrystals enable highly efficient reflective and semitransparent polymer solar cells

    KAUST Repository

    Jagadamma, Lethy Krishnan

    2016-09-09

    Solution-manufacturing of organic solar cells with best-in-class power conversion efficiency (PCE) will require all layers to be solution-coated without compromising solar cell performance. To date, the hole transporting layer (HTL) deposited on top of the organic bulk heterojunction layer in the inverted architecture is most commonly an ultrathin (<10 nm) metal oxide layer prepared by vacuum-deposition. Here, we show that an alcohol-based nanocrystalline MoOx suspension with carefully controlled nanocrystal (NC) size can yield state of the art reflective and semitransparent solar cells. Using NCs smaller than the target HTL thickness (∼10 nm) can yield compact, pinhole-free films which result in highly efficient polymer:fullerene bulk heterojunction (BHJ) solar cells with PCE=9.5%. The solution processed HTL is shown to achieve performance parity with vacuum-evaporated HTLs for several polymer:fullerene combinations and is even shown to work as hole injection layer in polymer light emitting diodes (PLED). We also demonstrate that larger MoOx NCs (30–50 nm) successfully composite MoOx with Ag nanowires (NW) to form a highly conducting, transparent top anode with exceptional contact properties. This yields state-of-the-art semitransparent polymer: fullerene solar cells with PCE of 6.5% and overall transmission >30%. The remarkable performance of reflective and semitransparent OPVs is due to the uncommonly high fill factors achieved using a carefully designed strategy for implementation of MoOx nanocrystals as HTL materials. © 2016 Elsevier Ltd

  18. Hydrothermal Processes

    Science.gov (United States)

    German, C. R.; von Damm, K. L.

    2003-12-01

    What is Hydrothermal Circulation?Hydrothermal circulation occurs when seawater percolates downward through fractured ocean crust along the volcanic mid-ocean ridge (MOR) system. The seawater is first heated and then undergoes chemical modification through reaction with the host rock as it continues downward, reaching maximum temperatures that can exceed 400 °C. At these temperatures the fluids become extremely buoyant and rise rapidly back to the seafloor where they are expelled into the overlying water column. Seafloor hydrothermal circulation plays a significant role in the cycling of energy and mass between the solid earth and the oceans; the first identification of submarine hydrothermal venting and their accompanying chemosynthetically based communities in the late 1970s remains one of the most exciting discoveries in modern science. The existence of some form of hydrothermal circulation had been predicted almost as soon as the significance of ridges themselves was first recognized, with the emergence of plate tectonic theory. Magma wells up from the Earth's interior along "spreading centers" or "MORs" to produce fresh ocean crust at a rate of ˜20 km3 yr-1, forming new seafloor at a rate of ˜3.3 km2 yr-1 (Parsons, 1981; White et al., 1992). The young oceanic lithosphere formed in this way cools as it moves away from the ridge crest. Although much of this cooling occurs by upward conduction of heat through the lithosphere, early heat-flow studies quickly established that a significant proportion of the total heat flux must also occur via some additional convective process (Figure 1), i.e., through circulation of cold seawater within the upper ocean crust (Anderson and Silbeck, 1981). (2K)Figure 1. Oceanic heat flow versus age of ocean crust. Data from the Pacific, Atlantic, and Indian oceans, averaged over 2 Ma intervals (circles) depart from the theoretical cooling curve (solid line) indicating convective cooling of young ocean crust by circulating seawater

  19. Multidimensional process discovery

    NARCIS (Netherlands)

    Ribeiro, J.T.S.

    2013-01-01

    Typically represented in event logs, business process data describe the execution of process events over time. Business process intelligence (BPI) techniques such as process mining can be applied to get strategic insight into business processes. Process discovery, conformance checking and

  20. PC image processing

    International Nuclear Information System (INIS)

    Hwa, Mok Jin Il; Am, Ha Jeng Ung

    1995-04-01

    This book starts summary of digital image processing and personal computer, and classification of personal computer image processing system, digital image processing, development of personal computer and image processing, image processing system, basic method of image processing such as color image processing and video processing, software and interface, computer graphics, video image and video processing application cases on image processing like satellite image processing, color transformation of image processing in high speed and portrait work system.

  1. Fast ray-tracing of human eye optics on Graphics Processing Units.

    Science.gov (United States)

    Wei, Qi; Patkar, Saket; Pai, Dinesh K

    2014-05-01

    We present a new technique for simulating retinal image formation by tracing a large number of rays from objects in three dimensions as they pass through the optic apparatus of the eye to objects. Simulating human optics is useful for understanding basic questions of vision science and for studying vision defects and their corrections. Because of the complexity of computing such simulations accurately, most previous efforts used simplified analytical models of the normal eye. This makes them less effective in modeling vision disorders associated with abnormal shapes of the ocular structures which are hard to be precisely represented by analytical surfaces. We have developed a computer simulator that can simulate ocular structures of arbitrary shapes, for instance represented by polygon meshes. Topographic and geometric measurements of the cornea, lens, and retina from keratometer or medical imaging data can be integrated for individualized examination. We utilize parallel processing using modern Graphics Processing Units (GPUs) to efficiently compute retinal images by tracing millions of rays. A stable retinal image can be generated within minutes. We simulated depth-of-field, accommodation, chromatic aberrations, as well as astigmatism and correction. We also show application of the technique in patient specific vision correction by incorporating geometric models of the orbit reconstructed from clinical medical images. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  2. Optimization of pinhole single photon emission computed tomography (pinhole SPECT) reconstruction; Optimisation de la reconstruction en tomographie d'emission monophotonique avec colimateur stenope

    Energy Technology Data Exchange (ETDEWEB)

    Israel-Jost, V

    2006-11-15

    In SPECT small animal imaging, it is highly recommended to accurately model the response of the detector in order to improve the low spatial resolution. The volume to reconstruct is thus obtained both by back-projecting and de-convolving the projections. We chose iterative methods, which permit one to solve the inverse problem independently from the model's complexity. We describe in this work a Gaussian model of point spread function (PSF) whose position, width and maximum are computed according to physical and geometrical parameters. Then we use the rotation symmetry to replace the computation of P projection operators, each one corresponding to one position of the detector around the object, by the computation of only one of them. This is achieved by choosing an appropriate polar discretization, for which we control the angular density of voxels to avoid over-sampling the center of the field of view. Finally, we propose a new family of algorithms, the so-called frequency adapted algorithms, which enable to optimize the reconstruction of a given band in the frequency domain on both the speed of convergence and the quality of the image. (author)

  3. Grief Tourism on Destination Image Formation: Afyonkarahisar and Başkomutan National Historical Park

    Directory of Open Access Journals (Sweden)

    Burhan KILIÇ

    2011-06-01

    Full Text Available The diversification of supply sources owned causes differences between destinations and special interest which is shaped for demand leads to become tourism widespread. In Turkey, there are many destinations where different features exist together. By means of alternative tourism types, various destinations and tourism types emerge. When all the events happened during the Independence War are considered in terms of national heritage, Afyonkarahisar is an important centre among grief tourism destinations. In research related to image components of Afyonkarahisar, confectionery, food products, and thermal tourism are the values of this destination that come to mind first. When the city is considered in terms of tourism, by highlighting the thermal tourism, the slogan “The Capital of Thermal Tourism” has been used. However it is hard to say that thermal tourism has a success taking the research into consideration. Therefore either other tourism values will be used to support the slogan available or with the work of a new image, a new image destination image will be created. The aim of this study is to eliminate the current negativity of Afyonkarahisar province’s destination image, strengthen the image and examine the availability of grief tourism which is one of the heritage tourism types so as to increase its market share

  4. Factors Affecting University Image Formation among Prospective Higher Education Students: The Case of International Branch Campuses

    Science.gov (United States)

    Wilkins, Stephen; Huisman, Jeroen

    2015-01-01

    Previous research has found that the images of universities formed by prospective students greatly influence their choices. With the advent of international branch campuses in several higher education hubs worldwide, many international students now attempt to construct images of these institutions when deciding where to study. The aim of this…

  5. Wide-Angle Multistatic Synthetic Aperture Radar: Focused Image Formation and Aliasing Artifact Mitigation

    National Research Council Canada - National Science Library

    Luminati, Jonathan E

    2005-01-01

    ...) imagery from a Radar Cross Section (RCS) chamber validates this approach. The second implementation problem stems from the large Doppler spread in the wide-angle scene, leading to severe aliasing problems...

  6. Image formation in weak gravitational lensing by tidal charged black holes

    International Nuclear Information System (INIS)

    Horvath, Zsolt; Gergely, Laszlo Arpad; Hobill, David

    2010-01-01

    We derive a generic weak lensing equation and apply it for the study of images produced by tidal charged brane black holes. We discuss the similarities and point out the differences with respect to the Schwarzschild black hole weak lensing, to both first- and second-order accuracy, when either the mass or the tidal charge dominates. In the case of mass-dominated weak lensing, we analyze the position of the images, the magnification factors and the flux ratio, as compared to the Schwarzschild lensing. The most striking modification appears in the flux ratio. When the tidal charge represents the dominating lensing effect, the number and orientation of the images with respect to the optical axis resembles the lensing properties of a Schwarzschild geometry, where the sign associated with the mass is opposite to that for the tidal charge. Finally it is found that the ratio of the brightness of the images as a function of image separation in the case of tidal charged black holes obeys a power-law relation significantly different from that of Schwarzschild black holes. This might provide a means for determining the underlying spacetime structure.

  7. The impact of category prices on store price image formation : An empirical analysis

    NARCIS (Netherlands)

    Da Silva Lourenço, C.J.; Gijsbrechts, E.; Paap, R.

    2015-01-01

    The authors empirically explore how consumers update beliefs about a store's overall expensiveness. They estimate a learning model of store price image (SPI) formation with the impact of actual prices linked to category characteristics, on a unique dataset combining store visit and purchase

  8. On the image formation in x-ray radiography using aligned carbon nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Okuyama, F., E-mail: okuya@mui.biglobe.ne.jp

    2017-04-11

    Evidence is presented that field electrons emitted from vertically-aligned carbon nanofibers (CNFs) yield clearer x-ray images than do thermionic electrons, under the identical electron-optical condition. Specifically, the same sample, an LSI circuit, mounted on the same x-ray chamber could be imaged far more sharply with a CNF emitter than with a thermionic one. It is hypothesized that electrons discharged from CNF tips hit the target to form “discrete focal points” thereon, thereby generating multiple x-ray beams that interplay to form a brilliant, sharply-delineated x-ray image. This hypothesis may stimulate open discussion on how to define the “focal point” for the x-ray imaging using nano-structured electron sources. Also, the improved resolution attained with CNFs might indicate that the heat generation originating in electron-target interactions is not so serious in the present field-emission mode. - Highlights: • Field-emission (FE) x-ray radiography (XR) is based on nanotechnology. • FE-XR surpasses thermionic XR in image resolution and brilliance. • Highly-resolved FE-XR images are due possibly to a discrete array of x-ray spots. • This hypothesis stimulates open discussion on how to define the focal-point in FE-XR.

  9. Investigation of 3-D RCS Image formation of ships using ISAR

    CSIR Research Space (South Africa)

    Lord, RT

    2006-05-01

    Full Text Available Conventional Inverse Synthetic Aperture Radar (ISAR) utilises the rotational motion of a target such as a ship or an aircraft to obtain a 2-D image of the target’s radar cross section (RCS) profile from a coherent radar system. This concept can...

  10. MapX: 2D XRF for Planetary Exploration - Image Formation and Optic Characterization

    Science.gov (United States)

    Sarrazin, P.; Blake, D.; Gailhanou, M.; Marchis, F.; Chalumeau, C.; Webb, S.; Walter, P.; Schyns, E.; Thompson, K.; Bristow, T.

    2018-04-01

    Map-X is a planetary instrument concept for 2D X-Ray Fluorescence (XRF) spectroscopy. The instrument is placed directly on the surface of an object and held in a fixed position during the measurement. The formation of XRF images on the CCD detector relies on a multichannel optic configured for 1:1 imaging and can be analyzed through the point spread function (PSF) of the optic. The PSF can be directly measured using a micron-sized monochromatic X-ray source in place of the sample. Such PSF measurements were carried out at the Stanford Synchrotron and are compared with ray tracing simulations. It is shown that artifacts are introduced by the periodicity of the PSF at the channel scale and the proximity of the CCD pixel size and the optic channel size. A strategy of sub-channel random moves was used to cancel out these artifacts and provide a clean experimental PSF directly usable for XRF image deconvolution.

  11. Image formation of brain function in patients suffering from knee osteoarthritis treated with moxibustion.

    Science.gov (United States)

    Xie, Hongwu; Xu, Fangming; Chen, Rixin; Luo, Tianyou; Chen, Mingren; Fang, Weidong; Lü, Fajin; Wu, Fei; Song, Yune; Xiong, Jun

    2013-04-01

    Functional magnetic resonance imaging (fMRI) technology was used to study changes to the resting state blood flow in the brains of patients with knee osteoarthritis (KOA) before and after treatment with moxibustion at the acupoint of the left Dubi (ST 35) and to probe the cerebral mechanism underlying the effect of moxibustion. The resting state brain function of 30 patients with left KOA was scanned with fMRI before and after treatment with moxibustion. The analytic methods of fractional amplitude of low frequency fluctuation (fALFF) and regional homogeneity (ReHo) were used to observe changes in resting state brain function. The fALFF values of the right cerebrum, extra-nucleus, left cerebellum, left cerebrum and white matter of patients after moxibustion treatment were higher than before treatment, and the fALFF values of the precentral gyrus, frontal lobe and occipital lobe were lower than before treatment (P or = 85). The ReHo values of the thalamus, extra-nucleus and parietal lobe of patients were much higher than those before moxibustion treatment, and the ReHo values of the right cerebrum, left cerebrum and frontal lobe were lower than before treatment (P or = 85). The influence of moxibustion on obvious changes in brain regions basically conforms to the way that pain and warmth is transmitted in the body, and the activation of sensitive systems in the body may be objective evidence of channel transmission. The regulation of brain function by moxibustion is not in a single brain region but rather in a network of many brain regions.

  12. On the image formation in x-ray radiography using aligned carbon nanofibers

    International Nuclear Information System (INIS)

    Okuyama, F.

    2017-01-01

    Evidence is presented that field electrons emitted from vertically-aligned carbon nanofibers (CNFs) yield clearer x-ray images than do thermionic electrons, under the identical electron-optical condition. Specifically, the same sample, an LSI circuit, mounted on the same x-ray chamber could be imaged far more sharply with a CNF emitter than with a thermionic one. It is hypothesized that electrons discharged from CNF tips hit the target to form “discrete focal points” thereon, thereby generating multiple x-ray beams that interplay to form a brilliant, sharply-delineated x-ray image. This hypothesis may stimulate open discussion on how to define the “focal point” for the x-ray imaging using nano-structured electron sources. Also, the improved resolution attained with CNFs might indicate that the heat generation originating in electron-target interactions is not so serious in the present field-emission mode. - Highlights: • Field-emission (FE) x-ray radiography (XR) is based on nanotechnology. • FE-XR surpasses thermionic XR in image resolution and brilliance. • Highly-resolved FE-XR images are due possibly to a discrete array of x-ray spots. • This hypothesis stimulates open discussion on how to define the focal-point in FE-XR.

  13. An Emphasis on Perception: Teaching Image Formation Using a Mechanistic Model of Vision.

    Science.gov (United States)

    Allen, Sue; And Others

    An effective way to teach the concept of image is to give students a model of human vision which incorporates a simple mechanism of depth perception. In this study two almost identical versions of a curriculum in geometrical optics were created. One used a mechanistic, interpretive eye model, and in the other the eye was modeled as a passive,…

  14. Virtual Ray Tracing as a Conceptual Tool for Image Formation in Mirrors and Lenses

    Science.gov (United States)

    Heikkinen, Lasse; Savinainen, Antti; Saarelainen, Markku

    2016-01-01

    The ray tracing method is widely used in teaching geometrical optics at the upper secondary and university levels. However, using simple and straightforward examples may lead to a situation in which students use the model of ray tracing too narrowly. Previous studies show that students seem to use the ray tracing method too concretely instead of…

  15. Linguistic means of Russian negative image formation in British media discourse in 2014-2015s

    Directory of Open Access Journals (Sweden)

    Boeva-Omelechko Natalya Borisovna

    2015-09-01

    Full Text Available The problem discussed in the article is topical due to the formation of the new branch of linguistics - imagology, dealing with means of formation of images of states. The authors analyze linguistic devices, used by British journalists for establishing negative associations with the name of our country in minds of British people. The main aim of these publications is to show the danger and threat, connected with our country and to form corresponding myths and stereotypes.

  16. Does the foveal shape influence the image formation in human eyes?

    Science.gov (United States)

    Frey, Katharina; Zimmerling, Beatrice; Scheibe, Patrick; Rauscher, Franziska G.; Reichenbach, Andreas; Francke, Mike; Brunner, Robert

    2017-10-01

    In human eyes, the maximum visual acuity correlates locally with the fovea, a shallow depression in the retina. Previous examinations have been reduced to simple geometrical fovea models derived from postmortem preparations and considering only a few superficial ray propagation aspects. In the current study, an extended and realistic analysis of ray-optical simulations for a comprehensive anatomical realistic eye model for the anterior part and realistic aspherical human foveal topographical profiles deduced from in vivo optical coherence tomography (OCT) are presented, and the refractive index step at the transition from vitreous to retinal tissue is taken into account. The optical effect of a commonly shaped (averaged) and an extraordinarily shaped foveal pit were both compared to the analysis of an assumed pure spherical boundary layer. The influence of the aperture size, wavelength, and incident angle on the spot size and shape, as well as the axial focal and lateral centroid position is investigated, and a lateral displacement of about 2 μm and an axial shift of the best focal position of less than 4 μm are found. These findings indicate only small optical effects that are laterally in the range of inter-receptor distances and axially less than the photoreceptor outer segment dimension.

  17. AN ADVANCED OXIDATION PROCESS : FENTON PROCESS

    Directory of Open Access Journals (Sweden)

    Engin GÜRTEKİN

    2008-03-01

    Full Text Available Biological wastewater treatment is not effective treatment method if raw wastewater contains toxic and refractory organics. Advanced oxidation processes are applied before or after biological treatment for the detoxification and reclamation of this kind of wastewaters. The advanced oxidation processes are based on the formation of powerful hydroxyl radicals. Among advanced oxidation processes Fenton process is one of the most promising methods. Because application of Fenton process is simple and cost effective and also reaction occurs in a short time period. Fenton process is applied for many different proposes. In this study, Fenton process was evaluated as an advanced oxidation process in wastewater treatment.

  18. Management of processes of electrochemical dimensional processing

    Science.gov (United States)

    Akhmetov, I. D.; Zakirova, A. R.; Sadykov, Z. B.

    2017-09-01

    In different industries a lot high-precision parts are produced from hard-processed scarce materials. Forming such details can only be acting during non-contact processing, or a minimum of effort, and doable by the use, for example, of electro-chemical processing. At the present stage of development of metal working processes are important management issues electrochemical machining and its automation. This article provides some indicators and factors of electrochemical machining process.

  19. On the relationship between stacking process and resolution. 2; Jugo shori to bunkaino ni kansuru kiso kenkyu. 2

    Energy Technology Data Exchange (ETDEWEB)

    Matsushima, J; Rokugawa, S; Kato, Y [The University of Tokyo, Tokyo (Japan). Faculty of Engineering; Yokota, T; Miyazaki, M [Geological Survey of Japan, Tsukuba (Japan)

    1997-05-27

    With respect to concept of resolution in seismic exploration using the reflection method, detailed considerations were given on processes of forming the resolution as a result of arranging observation points at vibration transmitting and receiving points. In the discussion, numerical experiments were carried out, in which the scattering stacking process is applied in a model having one scatterer existing in homogeneous media. The experiments investigated an imaging formation process of the scatterer when arrangement of the vibration transmitting and receiving points were changed from a coarse condition to a dense condition while the number of transmitting and receiving points is being increased. Resolution is created if waveforms having finite frequencies are used as input, and the imaging is performed by utilizing the limited number of vibration receiving and transmitting points. If the concept of equi-travel plane is used under these conditions, the equi-travel planes perform negation with each other, and it was indicated that visual resolution is expressed by how good the negating effect is. It was discovered that such concept of the resolution is quite ambiguous in terms of engineerings. 2 refs., 17 figs.

  20. Using the World Wide Web for GIDEP Problem Data Processing at Marshall Space Flight Center

    Science.gov (United States)

    McPherson, John W.; Haraway, Sandra W.; Whirley, J. Don

    1999-01-01

    Since April 1997, Marshall Space Flight Center has been using electronic transfer and the web to support our processing of the Government-Industry Data Exchange Program (GIDEP) and NASA ALERT information. Specific aspects include: (1) Extraction of ASCII text information from GIDEP for loading into Word documents for e-mail to ALERT actionees; (2) Downloading of GIDEP form image formats in Adobe Acrobat (.pdf) for internal storage display on the MSFC ALERT web page; (3) Linkage of stored GRDEP problem forms with summary information for access from the MSFC ALERT Distribution Summary Chart or from an html table of released MSFC ALERTs (4) Archival of historic ALERTs for reference by GIDEP ID, MSFC ID, or MSFC release date; (5) On-line tracking of ALERT response status using a Microsoft Access database and the web (6) On-line response to ALERTs from MSFC actionees through interactive web forms. The technique, benefits, effort, coordination, and lessons learned for each aspect are covered herein.

  1. Extensible packet processing architecture

    Science.gov (United States)

    Robertson, Perry J.; Hamlet, Jason R.; Pierson, Lyndon G.; Olsberg, Ronald R.; Chun, Guy D.

    2013-08-20

    A technique for distributed packet processing includes sequentially passing packets associated with packet flows between a plurality of processing engines along a flow through data bus linking the plurality of processing engines in series. At least one packet within a given packet flow is marked by a given processing engine to signify by the given processing engine to the other processing engines that the given processing engine has claimed the given packet flow for processing. A processing function is applied to each of the packet flows within the processing engines and the processed packets are output on a time-shared, arbitered data bus coupled to the plurality of processing engines.

  2. BPMN process views construction

    NARCIS (Netherlands)

    Yongchareon, S.; Liu, Chengfei; Zhao, X.; Kowalkiewicz, M.; Kitagawa, H.; Ishikawa, Y.

    2010-01-01

    Process view technology is catching more attentions in modern business process management, as it enables the customisation of business process representation. This capability helps improve the privacy protection, authority control, flexible display, etc., in business process modelling. One of

  3. Silicon integrated circuit process

    International Nuclear Information System (INIS)

    Lee, Jong Duck

    1985-12-01

    This book introduces the process of silicon integrated circuit. It is composed of seven parts, which are oxidation process, diffusion process, ion implantation process such as ion implantation equipment, damage, annealing and influence on manufacture of integrated circuit and device, chemical vapor deposition process like silicon Epitaxy LPCVD and PECVD, photolithography process, including a sensitizer, spin, harden bake, reflection of light and problems related process, infrared light bake, wet-etch, dry etch, special etch and problems of etching, metal process like metal process like metal-silicon connection, aluminum process, credibility of aluminum and test process.

  4. Silicon integrated circuit process

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Duck

    1985-12-15

    This book introduces the process of silicon integrated circuit. It is composed of seven parts, which are oxidation process, diffusion process, ion implantation process such as ion implantation equipment, damage, annealing and influence on manufacture of integrated circuit and device, chemical vapor deposition process like silicon Epitaxy LPCVD and PECVD, photolithography process, including a sensitizer, spin, harden bake, reflection of light and problems related process, infrared light bake, wet-etch, dry etch, special etch and problems of etching, metal process like metal process like metal-silicon connection, aluminum process, credibility of aluminum and test process.

  5. The Newest Laser Processing

    International Nuclear Information System (INIS)

    Lee, Baek Yeon

    2007-01-01

    This book mentions laser processing with laser principle, laser history, laser beam property, laser kinds, foundation of laser processing such as laser oscillation, characteristic of laser processing, laser for processing and its characteristic, processing of laser hole including conception of processing of laser hole and each material, and hole processing of metal material, cut of laser, reality of cut, laser welding, laser surface hardening, application case of special processing and safety measurement of laser.

  6. Minimal and careful processing

    OpenAIRE

    Nielsen, Thorkild

    2004-01-01

    In several standards, guidelines and publications, organic food processing is strongly associated with "minimal processing" and "careful processing". The term "minimal processing" is nowadays often used in the general food processing industry and described in literature. The term "careful processing" is used more specifically within organic food processing but is not yet clearly defined. The concept of carefulness seems to fit very well with the processing of organic foods, especially if it i...

  7. Thinning spatial point processes into Poisson processes

    DEFF Research Database (Denmark)

    Møller, Jesper; Schoenberg, Frederic Paik

    2010-01-01

    are identified, and where we simulate backwards and forwards in order to obtain the thinned process. In the case of a Cox process, a simple independent thinning technique is proposed. In both cases, the thinning results in a Poisson process if and only if the true Papangelou conditional intensity is used, and......In this paper we describe methods for randomly thinning certain classes of spatial point processes. In the case of a Markov point process, the proposed method involves a dependent thinning of a spatial birth-and-death process, where clans of ancestors associated with the original points......, thus, can be used as a graphical exploratory tool for inspecting the goodness-of-fit of a spatial point process model. Several examples, including clustered and inhibitive point processes, are considered....

  8. Thinning spatial point processes into Poisson processes

    DEFF Research Database (Denmark)

    Møller, Jesper; Schoenberg, Frederic Paik

    , and where one simulates backwards and forwards in order to obtain the thinned process. In the case of a Cox process, a simple independent thinning technique is proposed. In both cases, the thinning results in a Poisson process if and only if the true Papangelou conditional intensity is used, and thus can......This paper describes methods for randomly thinning certain classes of spatial point processes. In the case of a Markov point process, the proposed method involves a dependent thinning of a spatial birth-and-death process, where clans of ancestors associated with the original points are identified...... be used as a diagnostic for assessing the goodness-of-fit of a spatial point process model. Several examples, including clustered and inhibitive point processes, are considered....

  9. A process insight repository supporting process optimization

    OpenAIRE

    Vetlugin, Andrey

    2012-01-01

    Existing solutions for analysis and optimization of manufacturing processes, such as online analysis processing or statistical calculations, have shortcomings that limit continuous process improvements. In particular, they lack means of storing and integrating the results of analysis. This makes the valuable information that can be used for process optimizations used only once and then disposed. The goal of the Advanced Manufacturing Analytics (AdMA) research project is to design an integrate...

  10. Process mining: making knowledge discovery process centric

    NARCIS (Netherlands)

    Aalst, van der W.M.P.

    2011-01-01

    Recently, the Task Force on Process Mining released the Process Mining Manifesto. The manifesto is supported by 53 organizations and 77 process mining experts contributed to it. The active contributions from end-users, tool vendors, consultants, analysts, and researchers illustrate the growing

  11. Business process model repositories : efficient process retrieval

    NARCIS (Netherlands)

    Yan, Z.

    2012-01-01

    As organizations increasingly work in process-oriented manner, the number of business process models that they develop and have to maintain increases. As a consequence, it has become common for organizations to have collections of hundreds or even thousands of business process models. When a

  12. Solution-processed efficient CdTe nanocrystal/CBD-CdS hetero-junction solar cells with ZnO interlayer

    International Nuclear Information System (INIS)

    Tian, Yiyao; Zhang, Yijie; Lin, Yizhao; Gao, Kuo; Zhang, Yunpeng; Liu, Kaiyi; Yang, Qianqian; Zhou, Xiao; Qin, Donghuan; Wu, Hongbin; Xia, Yuxin; Hou, Lintao; Lan, Linfeng; Chen, Junwu; Wang, Dan; Yao, Rihui

    2013-01-01

    CdTe nanocrystal (NC)/CdS p–n hetero-junction solar cells with an ITO/ZnO-In/CdS/CdTe/MoO x /Ag-inverted structure were prepared by using a layer-by-layer solution process. The CdS thin films were prepared by chemical bath deposition on top of ITO/ZnO-In and were found to be very compact and pin-hole free in a large area, which insured high quality CdTe NCs thin-film formation upon it. The device performance was strongly related to the CdCl 2 annealing temperature and annealing time. Devices exhibited power conversion efficiency (PCE) of 3.08 % following 400 °C CdCl 2 annealing for 5 min, which was a good efficiency for solution processed CdTe/CdS NC-inverted solar cells. By carefully designing and optimizing the CdCl 2 -annealing conditions (370 °C CdCl 2 annealing for about 15 min), the PCE of such devices showed a 21 % increase, in comparison to 400 °C CdCl 2 -annealing conditions, and reached a better PCE of 3.73 % while keeping a relatively high V OC of 0.49 V. This PCE value, to the best of our knowledge, is the highest PCE reported for solution processed CdTe–CdS NC solar cells. Moreover, the inverted solar cell device was very stable when kept under ambient conditions, less than 4 % degradation was observed in PCE after 40 days storage

  13. Solution-processed efficient CdTe nanocrystal/CBD-CdS hetero-junction solar cells with ZnO interlayer

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Yiyao; Zhang, Yijie; Lin, Yizhao; Gao, Kuo; Zhang, Yunpeng; Liu, Kaiyi; Yang, Qianqian [South China University of Technology, School of Materials Science and Engineering (China); Zhou, Xiao; Qin, Donghuan, E-mail: qindh@scut.edu.cn; Wu, Hongbin [South China University of Technology, Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices (China); Xia, Yuxin; Hou, Lintao [Jinan University, College of Science and Engineering (China); Lan, Linfeng; Chen, Junwu; Wang, Dan; Yao, Rihui [South China University of Technology, Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices (China)

    2013-11-15

    CdTe nanocrystal (NC)/CdS p–n hetero-junction solar cells with an ITO/ZnO-In/CdS/CdTe/MoO{sub x}/Ag-inverted structure were prepared by using a layer-by-layer solution process. The CdS thin films were prepared by chemical bath deposition on top of ITO/ZnO-In and were found to be very compact and pin-hole free in a large area, which insured high quality CdTe NCs thin-film formation upon it. The device performance was strongly related to the CdCl{sub 2} annealing temperature and annealing time. Devices exhibited power conversion efficiency (PCE) of 3.08 % following 400 °C CdCl{sub 2} annealing for 5 min, which was a good efficiency for solution processed CdTe/CdS NC-inverted solar cells. By carefully designing and optimizing the CdCl{sub 2}-annealing conditions (370 °C CdCl{sub 2} annealing for about 15 min), the PCE of such devices showed a 21 % increase, in comparison to 400 °C CdCl{sub 2}-annealing conditions, and reached a better PCE of 3.73 % while keeping a relatively high V{sub OC} of 0.49 V. This PCE value, to the best of our knowledge, is the highest PCE reported for solution processed CdTe–CdS NC solar cells. Moreover, the inverted solar cell device was very stable when kept under ambient conditions, less than 4 % degradation was observed in PCE after 40 days storage.

  14. Uranium enrichment. Enrichment processes

    International Nuclear Information System (INIS)

    Alexandre, M.; Quaegebeur, J.P.

    2009-01-01

    Despite the remarkable progresses made in the diversity and the efficiency of the different uranium enrichment processes, only two industrial processes remain today which satisfy all of enriched uranium needs: the gaseous diffusion and the centrifugation. This article describes both processes and some others still at the demonstration or at the laboratory stage of development: 1 - general considerations; 2 - gaseous diffusion: physical principles, implementation, utilisation in the world; 3 - centrifugation: principles, elementary separation factor, flows inside a centrifuge, modeling of separation efficiencies, mechanical design, types of industrial centrifuges, realisation of cascades, main characteristics of the centrifugation process; 4 - aerodynamic processes: vortex process, nozzle process; 5 - chemical exchange separation processes: Japanese ASAHI process, French CHEMEX process; 6 - laser-based processes: SILVA process, SILMO process; 7 - electromagnetic and ionic processes: mass spectrometer and calutron, ion cyclotron resonance, rotating plasmas; 8 - thermal diffusion; 9 - conclusion. (J.S.)

  15. The permanental process

    DEFF Research Database (Denmark)

    McCullagh, Peter; Møller, Jesper

    2006-01-01

    We extend the boson process first to a large class of Cox processes and second to an even larger class of infinitely divisible point processes. Density and moment results are studied in detail. These results are obtained in closed form as weighted permanents, so the extension i called a permanental...... process. Temporal extensions and a particularly tractable case of the permanental process are also studied. Extensions of the fermion process along similar lines, leading to so-called determinantal processes, are discussed....

  16. The permanent process

    DEFF Research Database (Denmark)

    Møller, Jesper; McCullagh, Peter

    We extend the boson process first to a large class of Cox processes and second an even larger class of infinitely divisible point processes. Density and moment results are studied in detail. These results are obtained in closed form as weighted permanents, so the extension is called a permanent...... process. Temporal extensions and a particularly tractable case of the permanent process are also studied. Extensions of the ferminon process along similar lines, leading to so-called determinant processes, are discussed at the end. While the permanent process is attractive, the determinant process...

  17. Explosive processes in nucleosynthesis

    International Nuclear Information System (INIS)

    Boyd, R.N.

    2002-01-01

    There are many explosive processes in nucleosynthesis: big bang nucleosynthesis, the rp-process, the γ-process, the ν-process, and the r-process. However, I will discuss just the rp-process and the r-process in detail, primarily because both seem to have been very active research areas of late, and because they have great potential for studies with radioactive nuclear beams. I will also discuss briefly the γ-process because of its inevitability in conjunction with the rp-process. (orig.)

  18. Process Intensification: A Perspective on Process Synthesis

    DEFF Research Database (Denmark)

    Lutze, Philip; Gani, Rafiqul; Woodley, John

    2010-01-01

    In recent years, process intensification (PI) has attracted considerable academic interest as a potential means for process improvement, to meet the increasing demands for sustainable production. A variety of intensified operations developed in academia and industry creates a large number...... of options to potentially improve the process but to identify the set of feasible solutions for PI in which the optimal can be found takes considerable resources. Hence, a process synthesis tool to achieve PI would potentially assist in the generation and evaluation of PI options. Currently, several process...... design tools with a clear focus on specific PI tasks exist. Therefore, in this paper, the concept of a general systematic framework for synthesis and design of PI options in hierarchical steps through analyzing an existing process, generating PI options in a superstructure and evaluating intensified...

  19. New tools for digital medical image processing implemented in DIP software

    International Nuclear Information System (INIS)

    Araujo, Erica A.C.; Santana, Ivan E.; Lima, Fernando R.A.; Viera, Jose W.

    2011-01-01

    The anthropomorphic models used in computational dosimetry, also called phantoms, are mostly built from stacks of images CT (Computed Tomography) or MRI (Magnetic Resonance Imaging) obtained from scans of patients or volunteers. The construction of voxel phantoms requires computational processing for transforming image formats, dimensional image compression (2D) to form three-dimensional arrays (3D), quantization, resampling, enhancement, restoration and image segmentation, among others. Hardly the computational dosimetry researcher finds all these skills into a single software and often it results in a decreased development of their research or inadequate use of alternative tools. The need to integrate the various tasks of the original digital image processing to obtain an image that can be used in a computational model of exposure led to the development of software DIP (Digital Image Processing). This software reads, writes and edits binary files containing the 3D matrix corresponding to a stack of cross-sectional images of a given geometry that can be a human body or other volume of interest. It can also read any type of computer image and do conversions. When the task involves only one output image, it is saved in the JPEG standard Windows. When it involves a stack of images, the binary output file is called SGI (Interactive Graphic Simulations, a symbol already used in other publications of the Research Group in Numerical Dosimetry). The following paper presents the third version of the DIP software and emphasizes the new tools it implemented. Currently it has the menus Basics, Views, Spatial Domain, Frequency Domain, Segmentations and Study. Each menu contains items and subitems with features that generally require an image as input and produce an image or an attribute in the output. (author)

  20. Mining processes in dentistry

    NARCIS (Netherlands)

    Mans, R.S.; Reijers, H.A.; van Genuchten, M.; Wismeijer, D.

    2012-01-01

    Business processes in dentistry are quickly evolving towards "digital dentistry". This means that many steps in the dental process will increasingly deal with computerized information or computerized half products. A complicating factor in the improvement of process performance in dentistry,

  1. Realtime Color Stereovision Processing

    National Research Council Canada - National Science Library

    Formwalt, Bryon

    2000-01-01

    .... This research takes a step forward in real time machine vision processing. It investigates techniques for implementing a real time stereovision processing system using two miniature color cameras...

  2. Business Process Customization using Process Merging Techniques

    NARCIS (Netherlands)

    Bulanov, Pavel; Lazovik, Alexander; Aiello, Marco

    2012-01-01

    One of the important application of service composition techniques lies in the field of business process management. Essentially a business process can be considered as a composition of services, which is usually prepared by domain experts, and many tasks still have to be performed manually. These

  3. From Process Understanding to Process Control

    NARCIS (Netherlands)

    Streefland, M.

    2010-01-01

    A licensed pharmaceutical process is required to be executed within the validated ranges throughout the lifetime of product manufacturing. Changes to the process usually require the manufacturer to demonstrate that the safety and efficacy of the product remains unchanged. Recent changes in the

  4. Use of multiple pinhole external scintigraphy to monitor tablet disintegration in vivo

    International Nuclear Information System (INIS)

    Theodorakis, M.C.; Devous, M.D.; Simpson, D.R.

    1982-01-01

    External scintigraphy is useful for observing the disintegration of capsules and tablets in the gastro-intestinal tract of man and animals. The sites of disintegration, completeness of disintegration, effectiveness of coatings and rate of transition through the intestinal tract can be investigated by this technique. Gamma cameras are coupled to a digital data processor, video image processor and image magnifier, for increased resolution. Disintegration times in vitro and in vivo are compared. (U.K.)

  5. Spirally-patterned pinhole arrays for long-term fluorescence cell imaging.

    Science.gov (United States)

    Koo, Bon Ung; Kang, YooNa; Moon, SangJun; Lee, Won Gu

    2015-11-07

    Fluorescence cell imaging using a fluorescence microscope is an extensively used technique to examine the cell nucleus, internal structures, and other cellular molecules with fluorescence response time and intensity. However, it is difficult to perform high resolution cell imaging for a long period of time with this technique due to necrosis and apoptosis depending on the type and subcellular location of the damage caused by phototoxicity. A large number of studies have been performed to resolve this problem, but researchers have struggled to meet the challenge between cellular viability and image resolution. In this study, we employ a specially designed disc to reduce cell damage by controlling total fluorescence exposure time without deterioration of the image resolution. This approach has many advantages such as, the apparatus is simple, cost-effective, and easily integrated into the optical pathway through a conventional fluorescence microscope.

  6. Idaho Chemical Processing Plant Process Efficiency improvements

    International Nuclear Information System (INIS)

    Griebenow, B.

    1996-03-01

    In response to decreasing funding levels available to support activities at the Idaho Chemical Processing Plant (ICPP) and a desire to be cost competitive, the Department of Energy Idaho Operations Office (DOE-ID) and Lockheed Idaho Technologies Company have increased their emphasis on cost-saving measures. The ICPP Effectiveness Improvement Initiative involves many activities to improve cost effectiveness and competitiveness. This report documents the methodology and results of one of those cost cutting measures, the Process Efficiency Improvement Activity. The Process Efficiency Improvement Activity performed a systematic review of major work processes at the ICPP to increase productivity and to identify nonvalue-added requirements. A two-phase approach was selected for the activity to allow for near-term implementation of relatively easy process modifications in the first phase while obtaining long-term continuous improvement in the second phase and beyond. Phase I of the initiative included a concentrated review of processes that had a high potential for cost savings with the intent of realizing savings in Fiscal Year 1996 (FY-96.) Phase II consists of implementing long-term strategies too complex for Phase I implementation and evaluation of processes not targeted for Phase I review. The Phase II effort is targeted for realizing cost savings in FY-97 and beyond

  7. Making process improvement 'stick'.

    Science.gov (United States)

    Studer, Quint

    2014-06-01

    To sustain gains from a process improvement initiative, healthcare organizations should: Explain to staff why a process improvement initiative is needed. Encourage leaders within the organization to champion the process improvement, and tie their evaluations to its outcomes. Ensure that both leaders and employees have the skills to help sustain the sought-after process improvements.

  8. Fractional Poisson process (II)

    International Nuclear Information System (INIS)

    Wang Xiaotian; Wen Zhixiong; Zhang Shiying

    2006-01-01

    In this paper, we propose a stochastic process W H (t)(H-bar (12,1)) which we call fractional Poisson process. The process W H (t) is self-similar in wide sense, displays long range dependence, and has more fatter tail than Gaussian process. In addition, it converges to fractional Brownian motion in distribution

  9. Genetic process mining

    NARCIS (Netherlands)

    Aalst, van der W.M.P.; Alves De Medeiros, A.K.; Weijters, A.J.M.M.; Ciardo, G.; Darondeau, P.

    2005-01-01

    The topic of process mining has attracted the attention of both researchers and tool vendors in the Business Process Management (BPM) space. The goal of process mining is to discover process models from event logs, i.e., events logged by some information system are used to extract information about

  10. Business process quality management

    NARCIS (Netherlands)

    Reijers, H.A.; Mendling, J.; Recker, J.; Brocke, vom J.; Rosemann, M.

    2010-01-01

    Abstract Process modeling is a central element in any approach to Business Process Management (BPM). However, what hinders both practitioners and aca demics is the lack of support for assessing the quality of process models — let alone realizing high quality process models. Existing frameworks are

  11. Shell coal gasification process

    Energy Technology Data Exchange (ETDEWEB)

    Hennekes, B. [Shell Global Solutions (US) Inc. (United States). Technology Marketing

    2002-07-01

    The presentation, on which 17 slides/overheads are included in the papers, explained the principles of the Shell coal gasification process and the methods incorporated for control of sulfur dioxide, nitrogen oxides, particulates and mercury. The economics of the process were discussed. The differences between gasification and burning, and the differences between the Shell process and other processes were discussed.

  12. Exploring processes and deviations

    NARCIS (Netherlands)

    Leemans, S.J.J.; Fahland, D.; Aalst, van der W.M.P.; Fournier, F.; Mendling, J.

    2015-01-01

    In process mining, one of the main challenges is to discover a process model, while balancing several quality criteria. This often requires repeatedly setting parameters, discovering a map and evaluating it, which we refer to as process exploration. Commercial process mining tools like Disco,

  13. Distributed genetic process mining

    NARCIS (Netherlands)

    Bratosin, C.C.; Sidorova, N.; Aalst, van der W.M.P.

    2010-01-01

    Process mining aims at discovering process models from data logs in order to offer insight into the real use of information systems. Most of the existing process mining algorithms fail to discover complex constructs or have problems dealing with noise and infrequent behavior. The genetic process

  14. Dosimetry and process control for radiation processing

    International Nuclear Information System (INIS)

    Mod Ali, N.

    2002-01-01

    Complete text of publication follows. Accurate radiation dosimetry can provide quality assurance in radiation processing. Considerable relevant experiences in dosimetry by the SSDL-MINT has necessitate the development of methods making measurement at gamma plant traceable to the national standard. It involves the establishment of proper calibration procedure and selection of appropriate transfer system/technique to assure adequate traceability to a primary radiation standard. The effort forms the basis for irradiation process control, the legal approval of the process by the public health authorities (medical product sterilization and food preservation) and the safety and acceptance of the product

  15. Thin film processes

    CERN Document Server

    Vossen, John L

    1978-01-01

    Remarkable advances have been made in recent years in the science and technology of thin film processes for deposition and etching. It is the purpose of this book to bring together tutorial reviews of selected filmdeposition and etching processes from a process viewpoint. Emphasis is placed on the practical use of the processes to provide working guidelines for their implementation, a guide to the literature, and an overview of each process.

  16. A Campbell random process

    International Nuclear Information System (INIS)

    Reuss, J.D.; Misguich, J.H.

    1993-02-01

    The Campbell process is a stationary random process which can have various correlation functions, according to the choice of an elementary response function. The statistical properties of this process are presented. A numerical algorithm and a subroutine for generating such a process is built up and tested, for the physically interesting case of a Campbell process with Gaussian correlations. The (non-Gaussian) probability distribution appears to be similar to the Gamma distribution

  17. Business process transformation the process tangram framework

    CERN Document Server

    Sharma, Chitra

    2015-01-01

    This book presents a framework through transformation and explains  how business goals can be translated into realistic plans that are tangible and yield real results in terms of the top line and the bottom line. Process Transformation is like a tangram puzzle, which has multiple solutions yet is essentially composed of seven 'tans' that hold it together. Based on practical experience and intensive research into existing material, 'Process Tangram' is a simple yet powerful framework that proposes Process Transformation as a program. The seven 'tans' are: the transformation program itself, triggers, goals, tools and techniques, culture, communication and success factors. With its segregation into tans and division into core elements, this framework makes it possible to use 'pick and choose' to quickly and easily map an organization's specific requirements. Change management and process modeling are covered in detail. In addition, the book approaches managed services as a model of service delivery, which it ex...

  18. Dry process potentials

    International Nuclear Information System (INIS)

    Faugeras, P.

    1997-01-01

    Various dry processes have been studied and more or less developed in order particularly to reduce the waste quantities but none of them had replaced the PUREX process, for reasons departing to policy errors, un-appropriate demonstration examples or too late development, although realistic and efficient dry processes such as a fluoride selective volatility based processes have been demonstrated in France (CLOVIS, ATILA) and would be ten times cheaper than the PUREX process. Dry processes could regain interest in case of a nuclear revival (following global warming fears) or thermal wastes over-production. In the near future, dry processes could be introduced in complement to the PUREX process, especially at the end of the process cycle, for a more efficient recycling and safer storage (inactivation)

  19. Honing process optimization algorithms

    Science.gov (United States)

    Kadyrov, Ramil R.; Charikov, Pavel N.; Pryanichnikova, Valeria V.

    2018-03-01

    This article considers the relevance of honing processes for creating high-quality mechanical engineering products. The features of the honing process are revealed and such important concepts as the task for optimization of honing operations, the optimal structure of the honing working cycles, stepped and stepless honing cycles, simulation of processing and its purpose are emphasized. It is noted that the reliability of the mathematical model determines the quality parameters of the honing process control. An algorithm for continuous control of the honing process is proposed. The process model reliably describes the machining of a workpiece in a sufficiently wide area and can be used to operate the CNC machine CC743.

  20. Defense waste processing facility precipitate hydrolysis process

    International Nuclear Information System (INIS)

    Doherty, J.P.; Eibling, R.E.; Marek, J.C.

    1986-03-01

    Sodium tetraphenylborate and sodium titanate are used to assist in the concentration of soluble radionuclide in the Savannah River Plant's high-level waste. In the Defense Waste Processing Facility, concentrated tetraphenylborate/sodium titanate slurry containing cesium-137, strontium-90 and traces of plutonium from the waste tank farm is hydrolyzed in the Salt Processing Cell forming organic and aqueous phases. The two phases are then separated and the organic phase is decontaminated for incineration outside the DWPF building. The aqueous phase, containing the radionuclides and less than 10% of the original organic, is blended with the insoluble radionuclides in the high-level waste sludge and is fed to the glass melter for vitrification into borosilicate glass. During the Savannah River Laboratory's development of this process, copper (II) was found to act as a catalyst during the hydrolysis reactions, which improved the organic removal and simplified the design of the reactor

  1. The Diazo Copying Process.

    Science.gov (United States)

    Osterby, Bruce

    1989-01-01

    Described is an activity which demonstrates an organic-based reprographic method that is used extensively for the duplication of microfilm and engineering drawings. Discussed are the chemistry of the process and how to demonstrate the process for students. (CW)

  2. Waste processing air cleaning

    International Nuclear Information System (INIS)

    Kriskovich, J.R.

    1998-01-01

    Waste processing and preparing waste to support waste processing relies heavily on ventilation. Ventilation is used at the Hanford Site on the waste storage tanks to provide confinement, cooling, and removal of flammable gases

  3. Radiochemical Processing Laboratory (RPL)

    Data.gov (United States)

    Federal Laboratory Consortium — The Radiochemical Processing Laboratory (RPL)�is a scientific facility funded by DOE to create and implement innovative processes for environmental clean-up and...

  4. Laser material processing

    CERN Document Server

    Steen, William

    2010-01-01

    This text moves from the basics of laser physics to detailed treatments of all major materials processing techniques for which lasers are now essential. New chapters cover laser physics, drilling, micro- and nanomanufacturing and biomedical laser processing.

  5. Business Process Inventory

    Data.gov (United States)

    Office of Personnel Management — Inventory of maps and descriptions of the business processes of the U.S. Office of Personnel Management (OPM), with an emphasis on the processes of the Office of the...

  6. Process evaluation distributed system

    Science.gov (United States)

    Moffatt, Christopher L. (Inventor)

    2006-01-01

    The distributed system includes a database server, an administration module, a process evaluation module, and a data display module. The administration module is in communication with the database server for providing observation criteria information to the database server. The process evaluation module is in communication with the database server for obtaining the observation criteria information from the database server and collecting process data based on the observation criteria information. The process evaluation module utilizes a personal digital assistant (PDA). A data display module in communication with the database server, including a website for viewing collected process data in a desired metrics form, the data display module also for providing desired editing and modification of the collected process data. The connectivity established by the database server to the administration module, the process evaluation module, and the data display module, minimizes the requirement for manual input of the collected process data.

  7. Group Decision Process Support

    DEFF Research Database (Denmark)

    Gøtze, John; Hijikata, Masao

    1997-01-01

    Introducing the notion of Group Decision Process Support Systems (GDPSS) to traditional decision-support theorists.......Introducing the notion of Group Decision Process Support Systems (GDPSS) to traditional decision-support theorists....

  8. Cognitive processes in CBT

    NARCIS (Netherlands)

    Becker, E.S.; Vrijsen, J.N.; Hofmann, S.G.; Asmundson, G.J.G.

    2017-01-01

    Automatic cognitive processing helps us navigate the world. However, if the emotional and cognitive interplay becomes skewed, those cognitive processes can become maladaptive and result in psychopathology. Although biases are present in most mental disorders, different disorders are characterized by

  9. Improving Healthcare Logistics Processes

    DEFF Research Database (Denmark)

    Feibert, Diana Cordes

    logistics processes in hospitals and aims to provide theoretically and empirically based evidence for improving these processes to both expand the knowledge base of healthcare logistics and provide a decision tool for hospital logistics managers to improve their processes. Case studies were conducted...... processes. Furthermore, a method for benchmarking healthcare logistics processes was developed. Finally, a theoretically and empirically founded framework was developed to support managers in making an informed decision on how to improve healthcare logistics processes. This study contributes to the limited...... literature concerned with the improvement of logistics processes in hospitals. Furthermore, the developed framework provides guidance for logistics managers in hospitals on how to improve their processes given the circumstances in which they operate....

  10. Flavor changing lepton processes

    International Nuclear Information System (INIS)

    Kuno, Yoshitaka

    2002-01-01

    The flavor changing lepton processes, or in another words the lepton flavor changing processes, are described with emphasis on the updated theoretical motivations and the on-going experimental progress on a new high-intense muon source. (author)

  11. Process innovation laboratory

    DEFF Research Database (Denmark)

    Møller, Charles

    2007-01-01

    to create a new methodology for developing and exploring process models and applications. The paper outlines the process innovation laboratory as a new approach to BPI. The process innovation laboratory is a comprehensive framework and a collaborative workspace for experimenting with process models....... The process innovation laboratory facilitates innovation by using an integrated action learning approach to process modelling in a controlled environment. The study is based on design science and the paper also discusses the implications to EIS research and practice......Most organizations today are required not only to operate effective business processes but also to allow for changing business conditions at an increasing rate. Today nearly every business relies on their enterprise information systems (EIS) for process integration and future generations of EIS...

  12. The Integrated Renovation Process

    DEFF Research Database (Denmark)

    Galiotto, Nicolas; Heiselberg, Per; Knudstrup, Mary-Ann

    The Integrated Renovation Process (IRP) is a user customized methodology based on judiciously selected constructivist and interactive multi-criteria decision making methods (Galiotto, Heiselberg, & Knudstrup, 2014 (expected)). When applied for home renovation, the Integrated Renovation Process...

  13. Wetland Groundwater Processes

    National Research Council Canada - National Science Library

    Williams, Greg

    1993-01-01

    This technical note summarizes hydrologic and hydraulic (H AND H) processes and the related terminology that will likely be encountered during an evaluation of the effect of ground-water processes on wetland function...

  14. Flue Gas Desulphurization Processes

    International Nuclear Information System (INIS)

    Aly, A.I.M.; Halhouli, K.A.; Abu-Ashur, B.M.

    1999-01-01

    Flue gas desulphurization process are discussed. These processes can be grouped into non-regenerable systems and regenerable systems. The non-regenerable systems produce a product which is either disposed of as waste or sold as a by-product e.g. lime/limestone process. While in the regenerable systems, e.g. Wellman-Lord process, the SO 2 is regenerated from the sorbent(sodium sulphite), which is returned to absorb more SO 2 . Also a newer technology for flue gas desulphurization is discussed. The Ispra process uses bromine as oxidant, producing HBr, from which bromine is regenerated by electrolysis. The only by-products of this process are sulphuric acid and hydrogen, which are both valuable products, and no waste products are produced. Suggested modifications on the process are made based on experimental investigations to improve the efficiency of the process and to reduce its costs

  15. Chemical radwaste solidification processes

    International Nuclear Information System (INIS)

    Malloy, C.W.

    1979-01-01

    Some of these processes and their problems are briefly reviewed: early cement systems; urea-formaldehyde; Dow solidification process; low-viscosity chemical agents (POLYPAC); and water-extensible polyester. 9 refs

  16. The plasma hearth process: Process residuals characterization

    International Nuclear Information System (INIS)

    Leatherman, G.L.; Geimer, R.; Batdorf, J.; Hassel, G.; Wolfe, P.; Carney, K.P.

    1994-01-01

    The Plasma Hearth Process (PHP) is a high-temperature waste treatment process being developed by Science Applications International Corporation (SAIC) for the Department of Energy (DOE) that destroys hazardous organics while stabilizing radionuclides and hazardous metals in a vitreous slag waste form. The PHP has potential application for the treatment of a wide range of mixed waste types in both the low-level and transuranic (TRU) mixed waste categories. DOE, through the Office of Technology Development's Mixed Waste Integrated Program (MWIP) is conducting a three phase development project to ready the PHP for implementation in the DOE complex

  17. Process and device for processing radioactive wastes

    International Nuclear Information System (INIS)

    1974-01-01

    A method is described for processing liquid radioactive wastes. It includes the heating of the liquid wastes so that the contained liquids are evaporated and a practically anhydrous mass of solid particles inferior in volume to that of the wastes introduced is formed, then the transformation of the solid particles into a monolithic structure. This transformation includes the compressing of the particles and sintering or fusion. The solidifying agent is a mixture of polyethylene and paraffin wax or a styrene copolymer and a polyester resin. The device used for processing the radioactive liquid wastes is also described [fr

  18. Grind hardening process

    CERN Document Server

    Salonitis, Konstantinos

    2015-01-01

    This book presents the grind-hardening process and the main studies published since it was introduced in 1990s.  The modelling of the various aspects of the process, such as the process forces, temperature profile developed, hardness profiles, residual stresses etc. are described in detail. The book is of interest to the research community working with mathematical modeling and optimization of manufacturing processes.

  19. Software Process Improvement Defined

    DEFF Research Database (Denmark)

    Aaen, Ivan

    2002-01-01

    This paper argues in favor of the development of explanatory theory on software process improvement. The last one or two decades commitment to prescriptive approaches in software process improvement theory may contribute to the emergence of a gulf dividing theorists and practitioners....... It is proposed that this divide be met by the development of theory evaluating prescriptive approaches and informing practice with a focus on the software process policymaking and process control aspects of improvement efforts...

  20. Modeling multiphase materials processes

    CERN Document Server

    Iguchi, Manabu

    2010-01-01

    ""Modeling Multiphase Materials Processes: Gas-Liquid Systems"" describes the methodology and application of physical and mathematical modeling to multi-phase flow phenomena in materials processing. The book focuses on systems involving gas-liquid interaction, the most prevalent in current metallurgical processes. The performance characteristics of these processes are largely dependent on transport phenomena. This volume covers the inherent characteristics that complicate the modeling of transport phenomena in such systems, including complex multiphase structure, intense turbulence, opacity of

  1. Dosimetry for radiation processing

    DEFF Research Database (Denmark)

    Miller, Arne

    1986-01-01

    During the past few years significant advances have taken place in the different areas of dosimetry for radiation processing, mainly stimulated by the increased interest in radiation for food preservation, plastic processing and sterilization of medical products. Reference services both...... and sterilization dosimetry, optichromic dosimeters in the shape of small tubes for food processing, and ESR spectroscopy of alanine for reference dosimetry. In this paper the special features of radiation processing dosimetry are discussed, several commonly used dosimeters are reviewed, and factors leading...

  2. Generating process model collections

    NARCIS (Netherlands)

    Yan, Z.; Dijkman, R.M.; Grefen, P.W.P.J.

    2017-01-01

    Business process management plays an important role in the management of organizations. More and more organizations describe their operations as business processes. It is common for organizations to have collections of thousands of business processes, but for reasons of confidentiality these

  3. Multiphoton processes: conference proceedings

    International Nuclear Information System (INIS)

    Lambropoulos, P.; Smith, S.J.

    1984-01-01

    The chapters of this volume represent the invited papers delivered at the conference. They are arranged according to thermatic proximity beginning with atoms and continuing with molecules and surfaces. Section headings include multiphoton processes in atoms, field fluctuations and collisions in multiphoton process, and multiphoton processes in molecules and surfaces. Abstracts of individual items from the conference were prepared separately for the data base

  4. Semisolid Metal Processing Consortium

    Energy Technology Data Exchange (ETDEWEB)

    Apelian,Diran

    2002-01-10

    Mathematical modeling and simulations of semisolid filling processes remains a critical issue in understanding and optimizing the process. Semisolid slurries are non-Newtonian materials that exhibit complex rheological behavior. There the way these slurries flow in cavities is very different from the way liquid in classical casting fills cavities. Actually filling in semisolid processing is often counter intuitive

  5. How yogurt is processed

    Science.gov (United States)

    This month’s Processing column on the theme of “How Is It Processed?” focuses on yogurt. Yogurt is known for its health-promoting properties. This column will provide a brief overview of the history of yogurt and the current market. It will also unveil both traditional and modern yogurt processing t...

  6. Clinical Process Intelligence

    DEFF Research Database (Denmark)

    Vilstrup Pedersen, Klaus

    2006-01-01

    .e. local guidelines. From a knowledge management point of view, this externalization of generalized processes, gives the opportunity to learn from, evaluate and optimize the processes. "Clinical Process Intelligence" (CPI), will denote the goal of getting generalized insight into patient centered health...

  7. Process research and development

    Science.gov (United States)

    Bickler, D. B.

    1986-01-01

    The following major processes involved in the production of crystalline-silicon solar cells were discussed: surface preparation, junction formation, metallization, and assembly. The status of each of these processes, and the sequence in which these processes are applied, were described as they were in 1975, as they were in 1985, and what they might be in the future.

  8. The Constitutional Amendment Process

    Science.gov (United States)

    Chism, Kahlil

    2005-01-01

    This article discusses the constitutional amendment process. Although the process is not described in great detail, Article V of the United States Constitution allows for and provides instruction on amending the Constitution. While the amendment process currently consists of six steps, the Constitution is nevertheless quite difficult to change.…

  9. Coded aperture tomography revisited

    International Nuclear Information System (INIS)

    Bizais, Y.; Rowe, R.W.; Zubal, I.G.; Bennett, G.W.; Brill, A.B.

    1983-01-01

    Coded aperture (CA) Tomography never achieved wide spread use in Nuclear Medicine, except for the degenerate case of Seven Pinhole tomagraphy (7PHT). However it enjoys several attractive features (high sensitivity and tomographic ability with a statis detector). On the other hand, resolution is usually poor especially along the depth axis and the reconstructed volume is rather limited. Arguments are presented justifying the position that CA tomography can be useful for imaging time-varying 3D structures, if its major drawbacks (poor longitudinal resolution and difficulty in quantification) are overcome. Poor results obtained with 7PHT can be explained by both a very limited angular range sampled and a crude modelling of the image formation process. Therefore improvements can be expected by the use of a dual-detector system, along with a better understanding of its sampling properties and the use of more powerful reconstruction algorithms. Non overlapping multipinhole plates, because they do not involve a decoding procedure, should be considered first for practical applications. Use of real CA should be considered for cases in which non overlapping multipinhole plates do not lead to satisfactory solutions. We have been and currently are carrying out theoretical and experimental works, in order to define the factors which limit CA imaging and to propose satisfactory solutions for Dynamic Emission Tomography

  10. Teaching Process Design through Integrated Process Synthesis

    Science.gov (United States)

    Metzger, Matthew J.; Glasser, Benjamin J.; Patel, Bilal; Hildebrandt, Diane; Glasser, David

    2012-01-01

    The design course is an integral part of chemical engineering education. A novel approach to the design course was recently introduced at the University of the Witwatersrand, Johannesburg, South Africa. The course aimed to introduce students to systematic tools and techniques for setting and evaluating performance targets for processes, as well as…

  11. Statistical Process Control for KSC Processing

    Science.gov (United States)

    Ford, Roger G.; Delgado, Hector; Tilley, Randy

    1996-01-01

    The 1996 Summer Faculty Fellowship Program and Kennedy Space Center (KSC) served as the basis for a research effort into statistical process control for KSC processing. The effort entailed several tasks and goals. The first was to develop a customized statistical process control (SPC) course for the Safety and Mission Assurance Trends Analysis Group. The actual teaching of this course took place over several weeks. In addition, an Internet version of the same course complete with animation and video excerpts from the course when it was taught at KSC was developed. The application of SPC to shuttle processing took up the rest of the summer research project. This effort entailed the evaluation of SPC use at KSC, both present and potential, due to the change in roles for NASA and the Single Flight Operations Contractor (SFOC). Individual consulting on SPC use was accomplished as well as an evaluation of SPC software for KSC use in the future. A final accomplishment of the orientation of the author to NASA changes, terminology, data format, and new NASA task definitions will allow future consultation when the needs arise.

  12. Process-based costing.

    Science.gov (United States)

    Lee, Robert H; Bott, Marjorie J; Forbes, Sarah; Redford, Linda; Swagerty, Daniel L; Taunton, Roma Lee

    2003-01-01

    Understanding how quality improvement affects costs is important. Unfortunately, low-cost, reliable ways of measuring direct costs are scarce. This article builds on the principles of process improvement to develop a costing strategy that meets both criteria. Process-based costing has 4 steps: developing a flowchart, estimating resource use, valuing resources, and calculating direct costs. To illustrate the technique, this article uses it to cost the care planning process in 3 long-term care facilities. We conclude that process-based costing is easy to implement; generates reliable, valid data; and allows nursing managers to assess the costs of new or modified processes.

  13. Colloid process engineering

    CERN Document Server

    Peukert, Wolfgang; Rehage, Heinz; Schuchmann, Heike

    2015-01-01

    This book deals with colloidal systems in technical processes and the influence of colloidal systems by technical processes. It explores how new measurement capabilities can offer the potential for a dynamic development of scientific and engineering, and examines the origin of colloidal systems and its use for new products. The future challenges to colloidal process engineering are the development of appropriate equipment and processes for the production and obtainment of multi-phase structures and energetic interactions in market-relevant quantities. The book explores the relevant processes and for controlled production and how they can be used across all scales.

  14. Nonaqueous processing methods

    International Nuclear Information System (INIS)

    Coops, M.S.; Bowersox, D.F.

    1984-09-01

    A high-temperature process utilizing molten salt extraction from molten metal alloys has been developed for purification of spent power reactor fuels. Experiments with laboratory-scale processing operations show that purification and throughput parameters comparable to the Barnwell Purex process can be achieved by pyrochemical processing in equipment one-tenth the size, with all wastes being discharged as stable metal alloys at greatly reduced volume and disposal cost. This basic technology can be developed for large-scale processing of spent reactor fuels. 13 references, 4 figures

  15. Data processing made simple

    CERN Document Server

    Wooldridge, Susan

    2013-01-01

    Data Processing: Made Simple, Second Edition presents discussions of a number of trends and developments in the world of commercial data processing. The book covers the rapid growth of micro- and mini-computers for both home and office use; word processing and the 'automated office'; the advent of distributed data processing; and the continued growth of database-oriented systems. The text also discusses modern digital computers; fundamental computer concepts; information and data processing requirements of commercial organizations; and the historical perspective of the computer industry. The

  16. Thin film processes II

    CERN Document Server

    Kern, Werner

    1991-01-01

    This sequel to the 1978 classic, Thin Film Processes, gives a clear, practical exposition of important thin film deposition and etching processes that have not yet been adequately reviewed. It discusses selected processes in tutorial overviews with implementation guide lines and an introduction to the literature. Though edited to stand alone, when taken together, Thin Film Processes II and its predecessor present a thorough grounding in modern thin film techniques.Key Features* Provides an all-new sequel to the 1978 classic, Thin Film Processes* Introduces new topics, and sever

  17. FFTF gas processing systems

    International Nuclear Information System (INIS)

    Halverson, T.G.

    1977-01-01

    The design and operation of the two radioactive gas processing systems at the Fast Flux Test Facility (FFTF) exemplifies the concept that will be used in the first generation of Liquid Metal Fast Breeder Reactors (LMFBR's). The two systems, the Radioactive Argon Processing System (RAPS) and the Cell Atmosphere Processing System (CAPS), process the argon and nitrogen used in the FFTF for cover gas on liquid metal systems and as inert atmospheres in steel lined cells housing sodium equipment. The RAPS specifically processes the argon cover gas from the reactor coolant system, providing for decontamination and eventual reuse. The CAPS processes radioactive gasses from inerted cells and other liquid metal cover gas systems, providing for decontamination and ultimate discharge to the atmosphere. The cryogenic processing of waste gas by both systems is described

  18. Poisson branching point processes

    International Nuclear Information System (INIS)

    Matsuo, K.; Teich, M.C.; Saleh, B.E.A.

    1984-01-01

    We investigate the statistical properties of a special branching point process. The initial process is assumed to be a homogeneous Poisson point process (HPP). The initiating events at each branching stage are carried forward to the following stage. In addition, each initiating event independently contributes a nonstationary Poisson point process (whose rate is a specified function) located at that point. The additional contributions from all points of a given stage constitute a doubly stochastic Poisson point process (DSPP) whose rate is a filtered version of the initiating point process at that stage. The process studied is a generalization of a Poisson branching process in which random time delays are permitted in the generation of events. Particular attention is given to the limit in which the number of branching stages is infinite while the average number of added events per event of the previous stage is infinitesimal. In the special case when the branching is instantaneous this limit of continuous branching corresponds to the well-known Yule--Furry process with an initial Poisson population. The Poisson branching point process provides a useful description for many problems in various scientific disciplines, such as the behavior of electron multipliers, neutron chain reactions, and cosmic ray showers

  19. Local contrast-enhanced MR images via high dynamic range processing.

    Science.gov (United States)

    Chandra, Shekhar S; Engstrom, Craig; Fripp, Jurgen; Neubert, Ales; Jin, Jin; Walker, Duncan; Salvado, Olivier; Ho, Charles; Crozier, Stuart

    2018-09-01

    To develop a local contrast-enhancing and feature-preserving high dynamic range (HDR) image processing algorithm for multichannel and multisequence MR images of multiple body regions and tissues, and to evaluate its performance for structure visualization, bias field (correction) mitigation, and automated tissue segmentation. A multiscale-shape and detail-enhancement HDR-MRI algorithm is applied to data sets of multichannel and multisequence MR images of the brain, knee, breast, and hip. In multisequence 3T hip images, agreement between automatic cartilage segmentations and corresponding synthesized HDR-MRI series were computed for mean voxel overlap established from manual segmentations for a series of cases. Qualitative comparisons between the developed HDR-MRI and standard synthesis methods were performed on multichannel 7T brain and knee data, and multisequence 3T breast and knee data. The synthesized HDR-MRI series provided excellent enhancement of fine-scale structure from multiple scales and contrasts, while substantially reducing bias field effects in 7T brain gradient echo, T 1 and T 2 breast images and 7T knee multichannel images. Evaluation of the HDR-MRI approach on 3T hip multisequence images showed superior outcomes for automatic cartilage segmentations with respect to manual segmentation, particularly around regions with hyperintense synovial fluid, across a set of 3D sequences. The successful combination of multichannel/sequence MR images into a single-fused HDR-MR image format provided consolidated visualization of tissues within 1 omnibus image, enhanced definition of thin, complex anatomical structures in the presence of variable or hyperintense signals, and improved tissue (cartilage) segmentation outcomes. © 2018 International Society for Magnetic Resonance in Medicine.

  20. A secondary fuel removal process: plasma processing

    Energy Technology Data Exchange (ETDEWEB)

    Min, J Y; Kim, Y S [Hanyang Univ., Seoul (Korea, Republic of); Bae, K K; Yang, M S [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1997-07-01

    Plasma etching process of UO{sub 2} by using fluorine containing gas plasma is studied as a secondary fuel removal process for DUPIC (Direct Use of PWR spent fuel Into Candu) process which is taken into consideration for potential future fuel cycle in Korea. CF{sub 4}/O{sub 2} gas mixture is chosen for reactant gas and the etching rates of UO{sub 2} by the gas plasma are investigated as functions of CF{sub 4}/O{sub 2} ratio, plasma power, substrate temperature, and plasma gas pressure. It is found that the optimum CF{sub 4}/O{sub 2} ratio is around 4:1 at all temperatures up to 400 deg C and the etching rate increases with increasing r.f. power and substrate temperature. Under 150W r.f. power the etching rate reaches 1100 monolayers/min at 400 deg C, which is equivalent to about 0.5mm/min. (author).

  1. The SILVA atomic process

    International Nuclear Information System (INIS)

    Cazalet, J.

    1997-01-01

    The SILVA laser isotope separation process is based on the laser selective photo-ionization of uranium atomic vapour; the process is presently under development by CEA and COGEMA in France, with the aim to reduce by a factor three the cost of uranium enrichment. The two main components of a SILVA process plant are the lasers (copper vapour lasers and dye lasers) and the separator for the vaporization (with a high energy electron beam), ionization and separation operations. Researches on the SILVA process started in 1985 and the technical and economical feasibility is to be demonstrated in 1997. The progresses of similar rival processes and other processes are discussed and the remaining research stages and themes of the SILVA program are presented

  2. Technology or Process First?

    DEFF Research Database (Denmark)

    Siurdyban, Artur Henryk; Svejvig, Per; Møller, Charles

    Enterprise Systems Management (ESM) and Business Pro- cess Management (BPM), although highly correlated, have evolved as alternative and mutually exclusive approaches to corporate infrastruc- ture. As a result, companies struggle to nd the right balance between technology and process factors...... in infrastructure implementation projects. The purpose of this paper is articulate a need and a direction to medi- ate between the process-driven and the technology-driven approaches. Using a cross-case analysis, we gain insight into two examples of sys- tems and process implementation. We highlight the dierences...... between them using strategic alignment, Enterprise Systems and Business Process Management theories. We argue that the insights from these cases can lead to a better alignment between process and technology. Implications for practice include the direction towards a closer integration of process...

  3. Badge Office Process Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Haurykiewicz, John Paul [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dinehart, Timothy Grant [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Parker, Robert Young [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-12

    The purpose of this process analysis was to analyze the Badge Offices’ current processes from a systems perspective and consider ways of pursuing objectives set forth by SEC-PS, namely increased customer flow (throughput) and reduced customer wait times. Information for the analysis was gathered for the project primarily through Badge Office Subject Matter Experts (SMEs), and in-person observation of prevailing processes. Using the information gathered, a process simulation model was constructed to represent current operations and allow assessment of potential process changes relative to factors mentioned previously. The overall purpose of the analysis was to provide SEC-PS management with information and recommendations to serve as a basis for additional focused study and areas for potential process improvements in the future.

  4. Business process transformation

    CERN Document Server

    Grover, Varun

    2015-01-01

    Featuring contributions from prominent thinkers and researchers, this volume in the ""Advances in Management Information Systems"" series provides a rich set of conceptual, empirical, and introspective studies that epitomize fundamental knowledge in the area of Business Process Transformation. Processes are interpreted broadly to include operational and managerial processes within and between organizations, as well as those involved in knowledge generation. Transformation includes radical and incremental change, its conduct, management, and outcome. The editors and contributing authors pay clo

  5. Rational Unified Process

    OpenAIRE

    Kopal, Nils

    2016-01-01

    In this German seminar paper, which was written in the year 2011 at the University of Duisburg for a Bachelor Colloquium in Applied computer science, we show a brief overview of the Rational Unified Process (RUP). Thus, interested students or generally interested people in software development gain a first impression of RUP. The paper includes a survey and overview of the underlying process structure, the phases of the process, its workflows, and describes the always by the RUP developers pos...

  6. Deference and Due Process

    OpenAIRE

    Vermeule, Cornelius Adrian

    2015-01-01

    In the textbooks, procedural due process is a strictly judicial enterprise; although substantive entitlements are created by legislative and executive action, it is for courts to decide independently what process the Constitution requires. The notion that procedural due process might be committed primarily to the discretion of the agencies themselves is almost entirely absent from the academic literature. The facts on the ground are very different. Thanks to converging strands of caselaw ...

  7. Process Improvement Essentials

    CERN Document Server

    Persse, James R

    2006-01-01

    Process Improvement Essentials combines the foundation needed to understand process improvement theory with the best practices to help individuals implement process improvement initiatives in their organization. The three leading programs: ISO 9001:2000, CMMI, and Six Sigma--amidst the buzz and hype--tend to get lumped together under a common label. This book delivers a combined guide to all three programs, compares their applicability, and then sets the foundation for further exploration.

  8. Basic digital signal processing

    CERN Document Server

    Lockhart, Gordon B

    1985-01-01

    Basic Digital Signal Processing describes the principles of digital signal processing and experiments with BASIC programs involving the fast Fourier theorem (FFT). The book reviews the fundamentals of the BASIC program, continuous and discrete time signals including analog signals, Fourier analysis, discrete Fourier transform, signal energy, power. The text also explains digital signal processing involving digital filters, linear time-variant systems, discrete time unit impulse, discrete-time convolution, and the alternative structure for second order infinite impulse response (IIR) sections.

  9. Multiphoton processes: conference proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Lambropoulos, P.; Smith, S.J. (eds.)

    1984-01-01

    The chapters of this volume represent the invited papers delivered at the conference. They are arranged according to thermatic proximity beginning with atoms and continuing with molecules and surfaces. Section headings include multiphoton processes in atoms, field fluctuations and collisions in multiphoton process, and multiphoton processes in molecules and surfaces. Abstracts of individual items from the conference were prepared separately for the data base. (GHT)

  10. TEP process flow diagram

    Energy Technology Data Exchange (ETDEWEB)

    Wilms, R Scott [Los Alamos National Laboratory; Carlson, Bryan [Los Alamos National Laboratory; Coons, James [Los Alamos National Laboratory; Kubic, William [Los Alamos National Laboratory

    2008-01-01

    This presentation describes the development of the proposed Process Flow Diagram (PFD) for the Tokamak Exhaust Processing System (TEP) of ITER. A brief review of design efforts leading up to the PFD is followed by a description of the hydrogen-like, air-like, and waterlike processes. Two new design values are described; the mostcommon and most-demanding design values. The proposed PFD is shown to meet specifications under the most-common and mostdemanding design values.

  11. Standard Model processes

    CERN Document Server

    Mangano, M.L.; Aguilar-Saavedra, Juan Antonio; Alekhin, S.; Badger, S.; Bauer, C.W.; Becher, T.; Bertone, V.; Bonvini, M.; Boselli, S.; Bothmann, E.; Boughezal, R.; Cacciari, M.; Carloni Calame, C.M.; Caola, F.; Campbell, J.M.; Carrazza, S.; Chiesa, M.; Cieri, L.; Cimaglia, F.; Febres Cordero, F.; Ferrarese, P.; D'Enterria, D.; Ferrera, G.; Garcia i Tormo, X.; Garzelli, M.V.; Germann, E.; Hirschi, V.; Han, T.; Ita, H.; Jäger, B.; Kallweit, S.; Karlberg, A.; Kuttimalai, S.; Krauss, F.; Larkoski, A.J.; Lindert, J.; Luisoni, G.; Maierhöfer, P.; Mattelaer, O.; Martinez, H.; Moch, S.; Montagna, G.; Moretti, M.; Nason, P.; Nicrosini, O.; Oleari, C.; Pagani, D.; Papaefstathiou, A.; Petriello, F.; Piccinini, F.; Pierini, M.; Pierog, T.; Pozzorini, S.; Re, E.; Robens, T.; Rojo, J.; Ruiz, R.; Sakurai, K.; Salam, G.P.; Salfelder, L.; Schönherr, M.; Schulze, M.; Schumann, S.; Selvaggi, M.; Shivaji, A.; Siodmok, A.; Skands, P.; Torrielli, P.; Tramontano, F.; Tsinikos, I.; Tweedie, B.; Vicini, A.; Westhoff, S.; Zaro, M.; Zeppenfeld, D.; CERN. Geneva. ATS Department

    2017-06-22

    This report summarises the properties of Standard Model processes at the 100 TeV pp collider. We document the production rates and typical distributions for a number of benchmark Standard Model processes, and discuss new dynamical phenomena arising at the highest energies available at this collider. We discuss the intrinsic physics interest in the measurement of these Standard Model processes, as well as their role as backgrounds for New Physics searches.

  12. Scientific information processing procedures

    Directory of Open Access Journals (Sweden)

    García, Maylin

    2013-07-01

    Full Text Available The paper systematizes several theoretical view-points on scientific information processing skill. It decomposes the processing skills into sub-skills. Several methods such analysis, synthesis, induction, deduction, document analysis were used to build up a theoretical framework. Interviews and survey to professional being trained and a case study was carried out to evaluate the results. All professional in the sample improved their performance in scientific information processing.

  13. Integrated Renovation Process

    DEFF Research Database (Denmark)

    Galiotto, Nicolas; Heiselberg, Per; Knudstrup, Mary-Ann

    2016-01-01

    renovation to be overcome. The homeowners were better integrated and their preferences and immaterial values were better taken into account. To keep the decision-making process economically viable and timely, the process as known today still needs to be improved, and new tools need to be developed....... This paper presents a new scheme: the integrated renovation process. One successful case study is introduced, and recommendations for future developments needed in the field are provided....

  14. Transuranium processing plant

    International Nuclear Information System (INIS)

    King, L.J.

    1983-01-01

    The Transuranium Processing Plant (TRU) is a remotely operated, hot-cell, chemical processing facility of advanced design. The heart of TRU is a battery of nine heavily shielded process cells housed in a two-story building. Each cell, with its 54-inch-thick walls of a special high-density concrete, has enough shielding to stop the neutrons and gamma radiation from 1 gram of 252/sub Cf/ and associated fission products. Four cells contain chemical processing equipment, three contain equipment for the preparation and inspection of HFIR targets, and two cells are used for analytical chemistry operations. In addition, there are eight laboratories used for process development, for part of the process-control analyses, and for product finishing operations. Although the Transuranium Processing Plant was built for the purpose of recovering transuranium elements from targets irradiated in the High Flux Isotope Reactor (HFIR), it is also a highly versatile facility which has extensive provisions for changing and modifying equipment. Thus, it was a relatively simple matter to install a Solvent Extraction Test Facility (SETF) in one of the TRU chemical processing cells for use in the evaluation and demonstration of solvent extraction flowsheets for the recovery of fissile and fertile materials from irradiated reactor fuels. The equipment in the SETF has been designed for process development and demonstrations and the particular type of mixer-settler contactors was chosen because it is easy to observe and sample

  15. Linearity in Process Languages

    DEFF Research Database (Denmark)

    Nygaard, Mikkel; Winskel, Glynn

    2002-01-01

    The meaning and mathematical consequences of linearity (managing without a presumed ability to copy) are studied for a path-based model of processes which is also a model of affine-linear logic. This connection yields an affine-linear language for processes, automatically respecting open......-map bisimulation, in which a range of process operations can be expressed. An operational semantics is provided for the tensor fragment of the language. Different ways to make assemblies of processes lead to different choices of exponential, some of which respect bisimulation....

  16. Refractometry in process engineering

    Energy Technology Data Exchange (ETDEWEB)

    Roepscher, H

    1980-02-01

    Following a brief historical introduction into general refractometry, the limiting angle refractometer is dealt with in the first section and the differential refractometer in the second section, as well as process engineering information on this measuring method being given. An attempt is made with an extensive close-to-practice description to introduce the planner and technician to this physical measuring method in process engineering in order that they be able to use it themselves if necessary. When properly applied, it can be a valuable help to process control in compliance with process automization.

  17. Process modeling style

    CERN Document Server

    Long, John

    2014-01-01

    Process Modeling Style focuses on other aspects of process modeling beyond notation that are very important to practitioners. Many people who model processes focus on the specific notation used to create their drawings. While that is important, there are many other aspects to modeling, such as naming, creating identifiers, descriptions, interfaces, patterns, and creating useful process documentation. Experience author John Long focuses on those non-notational aspects of modeling, which practitioners will find invaluable. Gives solid advice for creating roles, work produ

  18. The Critical Design Process

    DEFF Research Database (Denmark)

    Brunsgaard, Camilla; Knudstrup, Mary-Ann; Heiselberg, Per

    2014-01-01

    within Danish tradition of architecture and construction. The objective of the research presented in this paper, is to compare the different design processes behind the making of passive houses in a Danish context. We evaluated the process with regard to the integrated and traditional design process....... Data analysis showed that the majority of the consortiums worked in an integrated manner; though there was room for improvment. Additionally, the paper discusses the challanges of implementing the integrated design process in practice and suggests ways of overcomming some of the barriers . In doing so...

  19. Multimodal Processes Rescheduling

    DEFF Research Database (Denmark)

    Bocewicz, Grzegorz; Banaszak, Zbigniew A.; Nielsen, Peter

    2013-01-01

    Cyclic scheduling problems concerning multimodal processes are usually observed in FMSs producing multi-type parts where the Automated Guided Vehicles System (AGVS) plays a role of a material handling system. Schedulability analysis of concurrently flowing cyclic processes (SCCP) exe-cuted in the......Cyclic scheduling problems concerning multimodal processes are usually observed in FMSs producing multi-type parts where the Automated Guided Vehicles System (AGVS) plays a role of a material handling system. Schedulability analysis of concurrently flowing cyclic processes (SCCP) exe...

  20. Fuels Processing Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — NETL’s Fuels Processing Laboratory in Morgantown, WV, provides researchers with the equipment they need to thoroughly explore the catalytic issues associated with...

  1. Quantum information processing

    National Research Council Canada - National Science Library

    Leuchs, Gerd; Beth, Thomas

    2003-01-01

    ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5 SimulationofHamiltonians... References... 1 1 1 3 5 8 10 2 Quantum Information Processing and Error Correction with Jump Codes (G. Alber, M. Mussinger...

  2. Exhaust gas processing facility

    International Nuclear Information System (INIS)

    Terada, Shin-ichi.

    1995-01-01

    The facility of the present invention comprises a radioactive liquid storage vessel, an exhaust gas dehumidifying device for dehumidifying gases exhausted from the vessel and an exhaust gas processing device for reducing radioactive materials in the exhaust gases. A purified gas line is disposed to the radioactive liquid storage vessel for purging exhaust gases generated from the radioactive liquid, then dehumidified and condensed liquid is recovered, and exhaust gases are discharged through an exhaust gas pipe disposed downstream of the exhaust gas processing device. With such procedures, the scale of the exhaust gas processing facility can be reduced and exhaust gases can be processed efficiently. (T.M.)

  3. Chemical process hazards analysis

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-02-01

    The Office of Worker Health and Safety (EH-5) under the Assistant Secretary for the Environment, Safety and Health of the US Department (DOE) has published two handbooks for use by DOE contractors managing facilities and processes covered by the Occupational Safety and Health Administration (OSHA) Rule for Process Safety Management of Highly Hazardous Chemicals (29 CFR 1910.119), herein referred to as the PSM Rule. The PSM Rule contains an integrated set of chemical process safety management elements designed to prevent chemical releases that can lead to catastrophic fires, explosions, or toxic exposures. The purpose of the two handbooks, ``Process Safety Management for Highly Hazardous Chemicals`` and ``Chemical Process Hazards Analysis,`` is to facilitate implementation of the provisions of the PSM Rule within the DOE. The purpose of this handbook ``Chemical Process Hazards Analysis,`` is to facilitate, within the DOE, the performance of chemical process hazards analyses (PrHAs) as required under the PSM Rule. It provides basic information for the performance of PrHAs, and should not be considered a complete resource on PrHA methods. Likewise, to determine if a facility is covered by the PSM rule, the reader should refer to the handbook, ``Process Safety Management for Highly Hazardous Chemicals`` (DOE- HDBK-1101-96). Promulgation of the PSM Rule has heightened the awareness of chemical safety management issues within the DOE. This handbook is intended for use by DOE facilities and processes covered by the PSM rule to facilitate contractor implementation of the PrHA element of the PSM Rule. However, contractors whose facilities and processes not covered by the PSM Rule may also use this handbook as a basis for conducting process hazards analyses as part of their good management practices. This handbook explains the minimum requirements for PrHAs outlined in the PSM Rule. Nowhere have requirements been added beyond what is specifically required by the rule.

  4. Effect of Annealing Process on CH3NH3PbI3-XClX Film Morphology of Planar Heterojunction Perovskite Solar Cells with Optimal Compact TiO2 Layer

    Directory of Open Access Journals (Sweden)

    Dan Chen

    2017-01-01

    Full Text Available The morphology of compact TiO2 film used as an electron-selective layer and perovskite film used as a light absorption layer in planar perovskite solar cells has a significant influence on the photovoltaic performance of the devices. In this paper, the spin coating speed of the compact TiO2 is investigated in order to get a high-quality film and the compact TiO2 film exhibits pinhole- and crack-free films treated by 2000 rpm for 60 s. Furthermore, the effect of annealing process, including annealing temperature and annealing program, on CH3NH3PbI3-XClX film morphology is studied. At the optimal annealing temperature of 100°C, the CH3NH3PbI3-XClX morphology fabricated by multistep slow annealing method has smaller grain boundaries and holes than that prepared by one-step direct annealing method, which results in the reduction of grain boundary recombination and the increase of Voc. With all optimal procedures, a planar fluorine-doped tin oxide (FTO substrate/compact TiO2/CH3NH3PbI3-XClX/Spiro-MeOTAD/Au cell is prepared for an active area of 0.1 cm2. It has achieved a power conversion efficiency (PCE of 14.64%, which is 80.3% higher than the reference cell (8.12% PCE without optimal perovskite layer. We anticipate that the annealing process with optimal compact TiO2 layer would possibly become a promising method for future industrialization of planar perovskite solar cells.

  5. Processer og procesledelse

    DEFF Research Database (Denmark)

    Madsen, Benedicte

    Bogen udfolder, nuancerer og konkretiserer procesledelse ift. mentale, relationelle og organisatoriske processer. Eksempler på kapitel-overskrifter: Procesbegrebet, Rammesætning, Kontraktredskabet, Mødeledelse, Samtaler, Reflekterende positioner og processer, Konflikthåndtering og teamudvikling......, Invitation til det dialogiske rum - om at arbejde over og under stregen, og Mentale omstruktureringer....

  6. The Player Engagement Process

    DEFF Research Database (Denmark)

    Schoenau-Fog, Henrik

    2011-01-01

    , categories and triggers involved in this process. By applying grounded theory to the analysis of the responses, a process-oriented player engagement framework was developed and four main components consisting of objectives, activities, accomplishments and affects as well as the corresponding categories...

  7. Mineral Processing Technology Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2000-09-01

    This document represents the roadmap for Processing Technology Research in the US Mining Industry. It was developed based on the results of a Processing Technology Roadmap Workshop sponsored by the National Mining Association in conjunction with the US Department of Energy, Office of Energy Efficiency and Renewable Energy, Office of Industrial Technologies. The Workshop was held January 24 - 25, 2000.

  8. Process control program development

    International Nuclear Information System (INIS)

    Dameron, H.J.

    1985-01-01

    This paper details the development and implementation of a ''Process Control Program'' at Duke Power's three nuclear stations - Oconee, McGuire, and Catawba. Each station is required by Technical Specification to have a ''Process Control Program'' (PCP) to control all dewatering and/or solidification activities for radioactive wastes

  9. Valuing the Accreditation Process

    Science.gov (United States)

    Bahr, Maria

    2018-01-01

    The value of the National Association for Developmental Education (NADE) accreditation process is far-reaching. Not only do students and programs benefit from the process, but also the entire institution. Through data collection of student performance, analysis, and resulting action plans, faculty and administrators can work cohesively towards…

  10. CMOS/SOS processing

    Science.gov (United States)

    Ramondetta, P.

    1980-01-01

    Report describes processes used in making complementary - metal - oxide - semiconductor/silicon-on-sapphire (CMOS/SOS) integrated circuits. Report lists processing steps ranging from initial preparation of sapphire wafers to final mapping of "good" and "bad" circuits on a wafer.

  11. Management oriented process

    International Nuclear Information System (INIS)

    2004-01-01

    ANAV decided to implement process-oriented management by adopting the U. S. NEI (Nuclear Electric Industry) model. The article describes the initial phases of the project, its current status and future prospects. The project has been considered as an improvement in the areas of organization and human factors. Recently, IAEA standard drafts are including processes as an accepted management model. (Author)

  12. Hybrid quantum information processing

    Energy Technology Data Exchange (ETDEWEB)

    Furusawa, Akira [Department of Applied Physics, School of Engineering, The University of Tokyo (Japan)

    2014-12-04

    I will briefly explain the definition and advantage of hybrid quantum information processing, which is hybridization of qubit and continuous-variable technologies. The final goal would be realization of universal gate sets both for qubit and continuous-variable quantum information processing with the hybrid technologies. For that purpose, qubit teleportation with a continuousvariable teleporter is one of the most important ingredients.

  13. Industrial separation processes : fundamentals

    NARCIS (Netherlands)

    Haan, de A.B.; Bosch, Hans

    2013-01-01

    Separation processes on an industrial scale comprise well over half of the capital and operating costs. They are basic knowledge in every chemical engineering and process engineering study. This book provides comprehensive and fundamental knowledge of university teaching in this discipline,

  14. METAL PLATING PROCESS

    Science.gov (United States)

    Walker, D.E.; Noland, R.A.

    1958-08-12

    A process ts described for obtaining a closely bonded coating of steel or iron on uranium. The process consists of providing, between the steel and uramium. a layer of silver. amd then pressure rolling tbe assembly at about 600 deg C until a reduction of from l0 to 50% has been obtained.

  15. The Analytical Hierarchy Process

    DEFF Research Database (Denmark)

    Barfod, Michael Bruhn

    2007-01-01

    The technical note gathers the theory behind the Analytical Hierarchy Process (AHP) and present its advantages and disadvantages in practical use.......The technical note gathers the theory behind the Analytical Hierarchy Process (AHP) and present its advantages and disadvantages in practical use....

  16. Semantic Business Process Modeling

    OpenAIRE

    Markovic, Ivan

    2010-01-01

    This book presents a process-oriented business modeling framework based on semantic technologies. The framework consists of modeling languages, methods, and tools that allow for semantic modeling of business motivation, business policies and rules, and business processes. Quality of the proposed modeling framework is evaluated based on the modeling content of SAP Solution Composer and several real-world business scenarios.

  17. Process energy analysis

    International Nuclear Information System (INIS)

    Kaiser, V.

    1993-01-01

    In Chapter 2 process energy cost analysis for chemical processing is treated in a general way, independent of the specific form of energy and power production. Especially, energy data collection and data treatment, energy accounting (metering, balance setting), specific energy input, and utility energy costs and prices are discussed. (R.P.) 14 refs., 4 figs., 16 tabs

  18. Continuous affine processes

    DEFF Research Database (Denmark)

    Buchardt, Kristian

    2016-01-01

    Affine processes possess the property that expectations of exponential affine transformations are given by a set of Riccati differential equations, which is the main feature of this popular class of processes. In this paper we generalise these results for expectations of more general transformati...

  19. Food-Processing Wastes.

    Science.gov (United States)

    Frenkel, Val S; Cummings, Gregg A; Maillacheruvu, K Y; Tang, Walter Z

    2017-10-01

    Literature published in 2016 and early 2017 related to food processing wastes treatment for industrial applications are reviewed. This review is a subsection of the Treatment Systems section of the annual Water Environment Federation literature review and covers the following food processing industries and applications: general, meat and poultry, fruits and vegetables, dairy and beverage, and miscellaneous treatment of food wastes.

  20. Food processing and allergenicity.

    Science.gov (United States)

    Verhoeckx, Kitty C M; Vissers, Yvonne M; Baumert, Joseph L; Faludi, Roland; Feys, Marcel; Flanagan, Simon; Herouet-Guicheney, Corinne; Holzhauser, Thomas; Shimojo, Ryo; van der Bolt, Nieke; Wichers, Harry; Kimber, Ian

    2015-06-01

    Food processing can have many beneficial effects. However, processing may also alter the allergenic properties of food proteins. A wide variety of processing methods is available and their use depends largely on the food to be processed. In this review the impact of processing (heat and non-heat treatment) on the allergenic potential of proteins, and on the antigenic (IgG-binding) and allergenic (IgE-binding) properties of proteins has been considered. A variety of allergenic foods (peanuts, tree nuts, cows' milk, hens' eggs, soy, wheat and mustard) have been reviewed. The overall conclusion drawn is that processing does not completely abolish the allergenic potential of allergens. Currently, only fermentation and hydrolysis may have potential to reduce allergenicity to such an extent that symptoms will not be elicited, while other methods might be promising but need more data. Literature on the effect of processing on allergenic potential and the ability to induce sensitisation is scarce. This is an important issue since processing may impact on the ability of proteins to cause the acquisition of allergic sensitisation, and the subject should be a focus of future research. Also, there remains a need to develop robust and integrated methods for the risk assessment of food allergenicity. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Business process intelligence

    NARCIS (Netherlands)

    Castellanos, M.; Alves De Medeiros, A.K.; Mendling, J.; Weber, B.; Weijters, A.J.M.M.; Cardoso, J.; Aalst, van der W.M.P.

    2009-01-01

    Business Process Intelligence (BPI,) is an emerging area that is getting increasingly popularfor enterprises. The need to improve business process efficiency, to react quickly to changes and to meet regulatory compliance is among the main drivers for BPI. BPI refers to the application of Business

  2. Correctness of concurrent processes

    NARCIS (Netherlands)

    E.R. Olderog (Ernst-Rüdiger)

    1989-01-01

    textabstractA new notion of correctness for concurrent processes is introduced and investigated. It is a relationship P sat S between process terms P built up from operators of CCS [Mi 80], CSP [Ho 85] and COSY [LTS 79] and logical formulas S specifying sets of finite communication sequences as in

  3. Uranium processing and properties

    CERN Document Server

    2013-01-01

    Covers a broad spectrum of topics and applications that deal with uranium processing and the properties of uranium Offers extensive coverage of both new and established practices for dealing with uranium supplies in nuclear engineering Promotes the documentation of the state-of-the-art processing techniques utilized for uranium and other specialty metals

  4. Relational Processing Following Stroke

    Science.gov (United States)

    Andrews, Glenda; Halford, Graeme S.; Shum, David; Maujean, Annick; Chappell, Mark; Birney, Damian

    2013-01-01

    The research examined relational processing following stroke. Stroke patients (14 with frontal, 30 with non-frontal lesions) and 41 matched controls completed four relational processing tasks: sentence comprehension, Latin square matrix completion, modified Dimensional Change Card Sorting, and n-back. Each task included items at two or three…

  5. Contaminated nickel scrap processing

    International Nuclear Information System (INIS)

    Compere, A.L.; Griffith, W.L.; Hayden, H.W.; Johnson, J.S. Jr.; Wilson, D.F.

    1994-12-01

    The DOE will soon choose between treating contaminated nickel scrap as a legacy waste and developing high-volume nickel decontamination processes. In addition to reducing the volume of legacy wastes, a decontamination process could make 200,000 tons of this strategic metal available for domestic use. Contaminants in DOE nickel scrap include 234 Th, 234 Pa, 137 Cs, 239 Pu (trace), 60 Co, U, 99 Tc, and 237 Np (trace). This report reviews several industrial-scale processes -- electrorefining, electrowinning, vapormetallurgy, and leaching -- used for the purification of nickel. Conventional nickel electrolysis processes are particularly attractive because they use side-stream purification of process solutions to improve the purity of nickel metal. Additionally, nickel purification by electrolysis is effective in a variety of electrolyte systems, including sulfate, chloride, and nitrate. Conventional electrorefining processes typically use a mixed electrolyte which includes sulfate, chloride, and borate. The use of an electrorefining or electrowinning system for scrap nickel recovery could be combined effectively with a variety of processes, including cementation, solvent extraction, ion exchange, complex-formation, and surface sorption, developed for uranium and transuranic purification. Selected processes were reviewed and evaluated for use in nickel side-stream purification. 80 refs

  6. Production process of VE

    International Nuclear Information System (INIS)

    1987-07-01

    This book tells of synopsis of production process of VE(value engineering), object selection method and establishment of target, collection of object information, design of function, write improvement suggestion, evaluation of improvement suggestion, all sorts of worksheets of production process of VE, explanation of IE, explanation of PERT.

  7. Perspectives on Innovation Processes

    NARCIS (Netherlands)

    Garud, R.; Tuertscher, P.R.; Van de Ven, A.H.

    2013-01-01

    Innovation is often thought of as an outcome. In this chapter, we review the literatures on innovation processes pertaining to the invention, development, and implementation of ideas. In particular, we explore how these processes unfold within firms, across multi-party networks, and within

  8. Hyperspectral image processing methods

    Science.gov (United States)

    Hyperspectral image processing refers to the use of computer algorithms to extract, store and manipulate both spatial and spectral information contained in hyperspectral images across the visible and near-infrared portion of the electromagnetic spectrum. A typical hyperspectral image processing work...

  9. Methods of information processing

    Energy Technology Data Exchange (ETDEWEB)

    Kosarev, Yu G; Gusev, V D

    1978-01-01

    Works are presented on automation systems for editing and publishing operations by methods of processing symbol information and information contained in training selection (ranking of objectives by promise, classification algorithm of tones and noise). The book will be of interest to specialists in the automation of processing textural information, programming, and pattern recognition.

  10. Process for preparing radiopharmaceuticals

    International Nuclear Information System (INIS)

    Barak, M.; Winchell, H.S.

    1977-01-01

    A process for the preparation of technetium-99m labeled pharmaceuticals is disclosed. The process comprises initially isolating technetium-99m pertechnetate by adsorption upon an adsorbent packing in a chromatographic column. The technetium-99m is then eluted from the packing with a biological compound to form a radiopharmaceutical

  11. Contaminated nickel scrap processing

    Energy Technology Data Exchange (ETDEWEB)

    Compere, A.L.; Griffith, W.L.; Hayden, H.W.; Johnson, J.S. Jr.; Wilson, D.F.

    1994-12-01

    The DOE will soon choose between treating contaminated nickel scrap as a legacy waste and developing high-volume nickel decontamination processes. In addition to reducing the volume of legacy wastes, a decontamination process could make 200,000 tons of this strategic metal available for domestic use. Contaminants in DOE nickel scrap include {sup 234}Th, {sup 234}Pa, {sup 137}Cs, {sup 239}Pu (trace), {sup 60}Co, U, {sup 99}Tc, and {sup 237}Np (trace). This report reviews several industrial-scale processes -- electrorefining, electrowinning, vapormetallurgy, and leaching -- used for the purification of nickel. Conventional nickel electrolysis processes are particularly attractive because they use side-stream purification of process solutions to improve the purity of nickel metal. Additionally, nickel purification by electrolysis is effective in a variety of electrolyte systems, including sulfate, chloride, and nitrate. Conventional electrorefining processes typically use a mixed electrolyte which includes sulfate, chloride, and borate. The use of an electrorefining or electrowinning system for scrap nickel recovery could be combined effectively with a variety of processes, including cementation, solvent extraction, ion exchange, complex-formation, and surface sorption, developed for uranium and transuranic purification. Selected processes were reviewed and evaluated for use in nickel side-stream purification. 80 refs.

  12. Microcontroller base process emulator

    OpenAIRE

    Jovrea Titus Claudiu

    2009-01-01

    This paper describes the design of a microcontroller base emulator for a conventional industrial process. The emulator is made with microcontroller and is used for testing and evaluating the performances of the industrial regulators. The parameters of the emulated process are fully customizable online and downloadable thru a serial communication from a personal computer.

  13. Cementation process study

    International Nuclear Information System (INIS)

    Park, H.H.; Han, K.W.; Ahn, S.J.; Choi, K.S.; Lee, M.W.; Ryu, Y.K.

    1985-01-01

    In the cementation process study, in 1984, design of the waste treatment simulator was finished for the first step. We can experience not only the operation of solidification system but the design and construction of comming large scale plant through the design of cementation process. (Author)

  14. Monitoring of operating processes

    International Nuclear Information System (INIS)

    Barry, R.F.

    1981-01-01

    Apparatus is described for monitoring the processes of a nuclear reactor to detect off-normal operation of any process and for testing the monitoring apparatus. The processes are evaluated by response to their paramters, such as temperature, pressure, etc. The apparatus includes a pair of monitoring paths or signal processing units. Each unit includes facilities for receiving on a time-sharing basis, a status binary word made up of digits each indicating the status of a process, whether normal or off-normal, and test-signal binary words simulating the status binary words. The status words and test words are processed in succession during successive cycles. During each cycle, the two units receive the same status word and the same test word. The test words simulate the status words both when they indicate normal operation and when they indicate off-normal operation. Each signal-processing unit includes a pair of memories. Each memory receives a status word or a test word, as the case may be, and converts the received word into a converted status word or a converted test word. The memories of each monitoring unit operate into a non-coincidence which signals non-coincidence of the converted word out of one memory of a signal-processing unit not identical to the converted word of the other memory of the same unit

  15. Teaching the Writing Process

    Science.gov (United States)

    Keen, John

    2017-01-01

    This article outlines some cognitive process models of writing composition. Possible reasons why students' writing capabilities do not match their abilities in some other school subjects are explored. Research findings on the efficacy of process approaches to teaching writing are presented and potential shortcomings are discussed. Product-based…

  16. Heavy oils processing materials requirements crude processing

    Energy Technology Data Exchange (ETDEWEB)

    Sloley, Andrew W. [CH2M Hill, Englewood, CO (United States)

    2012-07-01

    Over time, recommended best practices for crude unit materials selection have evolved to accommodate new operating requirements, feed qualities, and product qualities. The shift to heavier oil processing is one of the major changes in crude feed quality occurring over the last 20 years. The three major types of crude unit corrosion include sulfidation attack, naphthenic acid attack, and corrosion resulting from hydrolyzable chlorides. Heavy oils processing makes all three areas worse. Heavy oils have higher sulfur content; higher naphthenic acid content; and are more difficult to desalt, leading to higher chloride corrosion rates. Materials selection involves two major criteria, meeting required safety standards, and optimizing economics of the overall plant. Proper materials selection is only one component of a plant integrity approach. Materials selection cannot eliminate all corrosion. Proper materials selection requires appropriate support from other elements of an integrity protection program. The elements of integrity preservation include: materials selection (type and corrosion allowance); management limits on operating conditions allowed; feed quality control; chemical additives for corrosion reduction; and preventive maintenance and inspection (PMI). The following discussion must be taken in the context of the application of required supporting work in all the other areas. Within that context, specific materials recommendations are made to minimize corrosion due to the most common causes in the crude unit. (author)

  17. Nuclear process heat

    International Nuclear Information System (INIS)

    Barnert, H.; Hohn, H.; Schad, M.; Schwarz, D.; Singh, J.

    1993-01-01

    In a system for the application of high temperature heat from the HTR one must distinguish between the current generation and the use of process heat. In this respect it is important that the current can be generated by dual purpose power plants. The process heat is used as sensible heat, vaporisation heat and as chemical energy at the chemical conversion for the conversion of raw materials, the refinement of fossil primary energy carriers and finally circuit processes for the fission of water. These processes supply the market for heat, fuels, motor fuels and basic materials. Fifteen examples of HTR heat processes from various projects and programmes are presented in form of energy balances, however in a rather short way. (orig./DG) [de

  18. Nonhomogeneous fractional Poisson processes

    Energy Technology Data Exchange (ETDEWEB)

    Wang Xiaotian [School of Management, Tianjin University, Tianjin 300072 (China)]. E-mail: swa001@126.com; Zhang Shiying [School of Management, Tianjin University, Tianjin 300072 (China); Fan Shen [Computer and Information School, Zhejiang Wanli University, Ningbo 315100 (China)

    2007-01-15

    In this paper, we propose a class of non-Gaussian stationary increment processes, named nonhomogeneous fractional Poisson processes W{sub H}{sup (j)}(t), which permit the study of the effects of long-range dependance in a large number of fields including quantum physics and finance. The processes W{sub H}{sup (j)}(t) are self-similar in a wide sense, exhibit more fatter tail than Gaussian processes, and converge to the Gaussian processes in distribution in some cases. In addition, we also show that the intensity function {lambda}(t) strongly influences the existence of the highest finite moment of W{sub H}{sup (j)}(t) and the behaviour of the tail probability of W{sub H}{sup (j)}(t)

  19. Nonhomogeneous fractional Poisson processes

    International Nuclear Information System (INIS)

    Wang Xiaotian; Zhang Shiying; Fan Shen

    2007-01-01

    In this paper, we propose a class of non-Gaussian stationary increment processes, named nonhomogeneous fractional Poisson processes W H (j) (t), which permit the study of the effects of long-range dependance in a large number of fields including quantum physics and finance. The processes W H (j) (t) are self-similar in a wide sense, exhibit more fatter tail than Gaussian processes, and converge to the Gaussian processes in distribution in some cases. In addition, we also show that the intensity function λ(t) strongly influences the existence of the highest finite moment of W H (j) (t) and the behaviour of the tail probability of W H (j) (t)

  20. Identification of wastewater processes

    DEFF Research Database (Denmark)

    Carstensen, Niels Jacob

    The introduction of on-line sensors for monitoring of nutrient salts concentrations on wastewater treatment plants with nutrient removal, opens a wide new area of modelling wastewater processes. The subject of this thesis is the formulation of operational dynamic models based on time series...... of ammonia, nitrate, and phosphate concentrations, which are measured in the aeration tanks of the biological nutrient removal system. The alternatign operation modes of the BIO-DENITRO and BIO-DENIPHO processes are of particular interest. Time series models of the hydraulic and biological processes are very......-known theory of the processes with the significant effects found in data. These models are called grey box models, and they contain rate expressions for the processes of influent load of nutrients, transport of nutrients between the aeration tanks, hydrolysis and growth of biomass, nitrification...

  1. Quantum independent increment processes

    CERN Document Server

    Franz, Uwe

    2006-01-01

    This is the second of two volumes containing the revised and completed notes of lectures given at the school "Quantum Independent Increment Processes: Structure and Applications to Physics". This school was held at the Alfried-Krupp-Wissenschaftskolleg in Greifswald in March, 2003, and supported by the Volkswagen Foundation. The school gave an introduction to current research on quantum independent increment processes aimed at graduate students and non-specialists working in classical and quantum probability, operator algebras, and mathematical physics. The present second volume contains the following lectures: "Random Walks on Finite Quantum Groups" by Uwe Franz and Rolf Gohm, "Quantum Markov Processes and Applications in Physics" by Burkhard Kümmerer, Classical and Free Infinite Divisibility and Lévy Processes" by Ole E. Barndorff-Nielsen, Steen Thorbjornsen, and "Lévy Processes on Quantum Groups and Dual Groups" by Uwe Franz.

  2. Integrated biofuels process synthesis

    DEFF Research Database (Denmark)

    Torres-Ortega, Carlo Edgar; Rong, Ben-Guang

    2017-01-01

    Second and third generation bioethanol and biodiesel are more environmentally friendly fuels than gasoline and petrodiesel, andmore sustainable than first generation biofuels. However, their production processes are more complex and more expensive. In this chapter, we describe a two-stage synthesis......% used for bioethanol process), and steam and electricity from combustion (54%used as electricity) in the bioethanol and biodiesel processes. In the second stage, we saved about 5% in equipment costs and 12% in utility costs for bioethanol separation. This dual synthesis methodology, consisting of a top......-level screening task followed by a down-level intensification task, proved to be an efficient methodology for integrated biofuel process synthesis. The case study illustrates and provides important insights into the optimal synthesis and intensification of biofuel production processes with the proposed synthesis...

  3. Managing Software Process Evolution

    DEFF Research Database (Denmark)

    This book focuses on the design, development, management, governance and application of evolving software processes that are aligned with changing business objectives, such as expansion to new domains or shifting to global production. In the context of an evolving business world, it examines...... the complete software process lifecycle, from the initial definition of a product to its systematic improvement. In doing so, it addresses difficult problems, such as how to implement processes in highly regulated domains or where to find a suitable notation system for documenting processes, and provides...... essential insights and tips to help readers manage process evolutions. And last but not least, it provides a wealth of examples and cases on how to deal with software evolution in practice. Reflecting these topics, the book is divided into three parts. Part 1 focuses on software business transformation...

  4. Beryllium chemistry and processing

    CERN Document Server

    Walsh, Kenneth A

    2009-01-01

    This book introduces beryllium; its history, its chemical, mechanical, and physical properties including nuclear properties. The 29 chapters include the mineralogy of beryllium and the preferred global sources of ore bodies. The identification and specifics of the industrial metallurgical processes used to form oxide from the ore and then metal from the oxide are thoroughly described. The special features of beryllium chemistry are introduced, including analytical chemical practices. Beryllium compounds of industrial interest are identified and discussed. Alloying, casting, powder processing, forming, metal removal, joining and other manufacturing processes are covered. The effect of composition and process on the mechanical and physical properties of beryllium alloys assists the reader in material selection. The physical metallurgy chapter brings conformity between chemical and physical metallurgical processing of beryllium, metal, alloys, and compounds. The environmental degradation of beryllium and its all...

  5. Business process support

    Energy Technology Data Exchange (ETDEWEB)

    Carle, Adriana; Fiducia, Daniel [Transportadora de Gas del Sur S.A. (TGS), Buenos Aires (Argentina)

    2005-07-01

    This paper is about the own development of business support software. The developed applications are used to support two business processes: one of them is the process of gas transportation and the other is the natural gas processing. This software has interphases with the ERP SAP, software SCADA and on line gas transportation simulation software. The main functionalities of the applications are: entrance on line real time of clients transport nominations, transport programming, allocation of the clients transport nominations, transport control, measurements, balanced pipeline, allocation of gas volume to the gas processing plants, calculate of product tons processed in each plant and tons of product distributed to clients. All the developed software generates information to the internal staff, regulatory authorities and clients. (author)

  6. Branching processes in biology

    CERN Document Server

    Kimmel, Marek

    2015-01-01

    This book provides a theoretical background of branching processes and discusses their biological applications. Branching processes are a well-developed and powerful set of tools in the field of applied probability. The range of applications considered includes molecular biology, cellular biology, human evolution and medicine. The branching processes discussed include Galton-Watson, Markov, Bellman-Harris, Multitype, and General Processes. As an aid to understanding specific examples, two introductory chapters, and two glossaries are included that provide background material in mathematics and in biology. The book will be of interest to scientists who work in quantitative modeling of biological systems, particularly probabilists, mathematical biologists, biostatisticians, cell biologists, molecular biologists, and bioinformaticians. The authors are a mathematician and cell biologist who have collaborated for more than a decade in the field of branching processes in biology for this new edition. This second ex...

  7. EDITORIAL: Industrial Process Tomography

    Science.gov (United States)

    Anton Johansen, Geir; Wang, Mi

    2008-09-01

    There has been tremendous development within measurement science and technology over the past couple of decades. New sensor technologies and compact versatile signal recovery electronics are continuously expanding the limits of what can be measured and the accuracy with which this can be done. Miniaturization of sensors and the use of nanotechnology push these limits further. Also, thanks to powerful and cost-effective computer systems, sophisticated measurement and reconstruction algorithms previously only accessible in advanced laboratories are now available for in situ online measurement systems. The process industries increasingly require more process-related information, motivated by key issues such as improved process control, process utilization and process yields, ultimately driven by cost-effectiveness, quality assurance, environmental and safety demands. Industrial process tomography methods have taken advantage of the general progress in measurement science, and aim at providing more information, both quantitatively and qualitatively, on multiphase systems and their dynamics. The typical approach for such systems has been to carry out one local or bulk measurement and assume that this is representative of the whole system. In some cases, this is sufficient. However, there are many complex systems where the component distribution varies continuously and often unpredictably in space and time. The foundation of industrial tomography is to conduct several measurements around the periphery of a multiphase process, and use these measurements to unravel the cross-sectional distribution of the process components in time and space. This information is used in the design and optimization of industrial processes and process equipment, and also to improve the accuracy of multiphase system measurements in general. In this issue we are proud to present a selection of the 145 papers presented at the 5th World Congress on Industrial Process Tomography in Bergen

  8. States in Process Calculi

    Directory of Open Access Journals (Sweden)

    Christoph Wagner

    2014-08-01

    Full Text Available Formal reasoning about distributed algorithms (like Consensus typically requires to analyze global states in a traditional state-based style. This is in contrast to the traditional action-based reasoning of process calculi. Nevertheless, we use domain-specific variants of the latter, as they are convenient modeling languages in which the local code of processes can be programmed explicitly, with the local state information usually managed via parameter lists of process constants. However, domain-specific process calculi are often equipped with (unlabeled reduction semantics, building upon a rich and convenient notion of structural congruence. Unfortunately, the price for this convenience is that the analysis is cumbersome: the set of reachable states is modulo structural congruence, and the processes' state information is very hard to identify. We extract from congruence classes of reachable states individual state-informative representatives that we supply with a proper formal semantics. As a result, we can now freely switch between the process calculus terms and their representatives, and we can use the stateful representatives to perform assertional reasoning on process calculus models.

  9. Welding processes handbook

    CERN Document Server

    Weman, Klas

    2003-01-01

    Deals with the main commercially significant and commonly used welding processes. This title takes the student or novice welder through the individual steps involved in each process in an easily understood way. It covers many of the requirements referred to in European Standards including EN719, EN 729, EN 729 and EN 287.$bWelding processes handbook is a concise, explanatory guide to the main commercially significant and commonly-used welding processes. It takes the novice welder or student through the individual steps involved in each process in a clear and easily understood way. It is intended to provide an up-to-date reference to the major applications of welding as they are used in industry. The contents have been arranged so that it can be used as a textbook for European welding courses in accordance with guidelines from the European Welding Federation. Welding processes and equipment necessary for each process are described so that they can be applied to all instruction levels required by the EWF and th...

  10. Organic waste incineration processes

    Energy Technology Data Exchange (ETDEWEB)

    Lemort, F.; Charvillat, J.P.; Nabot, J.P. [CEA Valrho, Bagnols sur Ceze Cedex (France); Chateauvieux, H.; Thiebaut, C. [CEA Valduc, 21 - Is-sur-Tille (France)

    2001-07-01

    Nuclear activities produce organic waste compatible with thermal processes designed to obtain a significant weight and volume reduction as well as to stabilize the inorganic residue in a form suitable for various interim storage or disposal routes. Several processes may be implemented (e.g. excess air, plasma, fluidized bed or rotating furnace) depending on the nature of the waste and the desired objectives. The authors focus on the IRIS rotating-kiln process, which was used for the first time with radioactive materials during the first half of 1999. IRIS is capable of processing highly chlorinated and {alpha}-contaminated waste at a rate of several kilograms per hour, while limiting corrosion due to chlorine as well as mechanical entrainment of radioactive particles in the off-gas stream. Although operated industrially, the process is under continual development to improve its performance and adapt it to a wider range of industrial applications. The main focus of attention today is on adapting the pyrolytic processes to waste with highly variable compositions and to enhance the efficiency of the off-gas purification systems. These subjects are of considerable interest for a large number of heat treatment processes (including all off-gas treatment systems) for which extremely durable, high-performance and low-flow electrostatic precipitators are now being developed. (author)

  11. Organic waste incineration processes

    International Nuclear Information System (INIS)

    Lemort, F.; Charvillat, J.P.; Nabot, J.P.; Chateauvieux, H.; Thiebaut, C.

    2001-01-01

    Nuclear activities produce organic waste compatible with thermal processes designed to obtain a significant weight and volume reduction as well as to stabilize the inorganic residue in a form suitable for various interim storage or disposal routes. Several processes may be implemented (e.g. excess air, plasma, fluidized bed or rotating furnace) depending on the nature of the waste and the desired objectives. The authors focus on the IRIS rotating-kiln process, which was used for the first time with radioactive materials during the first half of 1999. IRIS is capable of processing highly chlorinated and α-contaminated waste at a rate of several kilograms per hour, while limiting corrosion due to chlorine as well as mechanical entrainment of radioactive particles in the off-gas stream. Although operated industrially, the process is under continual development to improve its performance and adapt it to a wider range of industrial applications. The main focus of attention today is on adapting the pyrolytic processes to waste with highly variable compositions and to enhance the efficiency of the off-gas purification systems. These subjects are of considerable interest for a large number of heat treatment processes (including all off-gas treatment systems) for which extremely durable, high-performance and low-flow electrostatic precipitators are now being developed. (author)

  12. Quantitative comparison of clustered microcalcifications in for-presentation and for-processing mammograms in full-field digital mammography.

    Science.gov (United States)

    Wang, Juan; Nishikawa, Robert M; Yang, Yongyi

    2017-07-01

    Mammograms acquired with full-field digital mammography (FFDM) systems are provided in both "for-processing'' and "for-presentation'' image formats. For-presentation images are traditionally intended for visual assessment by the radiologists. In this study, we investigate the feasibility of using for-presentation images in computerized analysis and diagnosis of microcalcification (MC) lesions. We make use of a set of 188 matched mammogram image pairs of MC lesions from 95 cases (biopsy proven), in which both for-presentation and for-processing images are provided for each lesion. We then analyze and characterize the MC lesions from for-presentation images and compare them with their counterparts in for-processing images. Specifically, we consider three important aspects in computer-aided diagnosis (CAD) of MC lesions. First, we quantify each MC lesion with a set of 10 image features of clustered MCs and 12 textural features of the lesion area. Second, we assess the detectability of individual MCs in each lesion from the for-presentation images by a commonly used difference-of-Gaussians (DoG) detector. Finally, we study the diagnostic accuracy in discriminating between benign and malignant MC lesions from the for-presentation images by a pretrained support vector machine (SVM) classifier. To accommodate the underlying background suppression and image enhancement in for-presentation images, a normalization procedure is applied. The quantitative image features of MC lesions from for-presentation images are highly consistent with that from for-processing images. The values of Pearson's correlation coefficient between features from the two formats range from 0.824 to 0.961 for the 10 MC image features, and from 0.871 to 0.963 for the 12 textural features. In detection of individual MCs, the FROC curve from for-presentation is similar to that from for-processing. In particular, at sensitivity level of 80%, the average number of false-positives (FPs) per image region is 9

  13. IT Project Prioritization Process

    DEFF Research Database (Denmark)

    Shollo, Arisa; Constantiou, Ioanna

    2013-01-01

    In most of the large companies IT project prioritization process is designed based on principles of evidencebased management. We investigate a case of IT project prioritization in a financial institution, and in particular, how managers practice evidence-based management during this process. We use...... a rich dataset built from a longitudinal study of the prioritization process for the IT projects. Our findings indicate that managers reach a decision not only by using evidence but from the interplay between the evidence and the judgment devices that managers employ. The interplay between evidence...

  14. Revealing the programming process

    DEFF Research Database (Denmark)

    Bennedsen, Jens; Caspersen, Michael Edelgaard

    2005-01-01

    One of the most important goals of an introductory programming course is that the students learn a systematic approach to the development of computer programs. Revealing the programming process is an important part of this; however, textbooks do not address the issue -- probably because...... the textbook medium is static and therefore ill-suited to expose the process of programming. We have found that process recordings in the form of captured narrated programming sessions are a simple, cheap, and efficient way of providing the revelation.We identify seven different elements of the programming...

  15. Process of performance assessment

    International Nuclear Information System (INIS)

    King, C.M.; Halford, D.K.

    1987-01-01

    Performance assessment is the process used to evaluate the environmental consequences of disposal of radioactive waste in the biosphere. An introductory review of the subject is presented. Emphasis is placed on the process of performance assessment from the standpoint of defining the process. Performance assessment, from evolving experience at DOE sites, has short-term and long-term subprograms, the components of which are discussed. The role of mathematical modeling in performance assessment is addressed including the pros and cons of current approaches. Finally, the system/site/technology issues as the focal point of this symposium are reviewed

  16. Semi-Markov processes

    CERN Document Server

    Grabski

    2014-01-01

    Semi-Markov Processes: Applications in System Reliability and Maintenance is a modern view of discrete state space and continuous time semi-Markov processes and their applications in reliability and maintenance. The book explains how to construct semi-Markov models and discusses the different reliability parameters and characteristics that can be obtained from those models. The book is a useful resource for mathematicians, engineering practitioners, and PhD and MSc students who want to understand the basic concepts and results of semi-Markov process theory. Clearly defines the properties and

  17. Irreversible processes kinetic theory

    CERN Document Server

    Brush, Stephen G

    2013-01-01

    Kinetic Theory, Volume 2: Irreversible Processes deals with the kinetic theory of gases and the irreversible processes they undergo. It includes the two papers by James Clerk Maxwell and Ludwig Boltzmann in which the basic equations for transport processes in gases are formulated, together with the first derivation of Boltzmann's ""H-theorem"" and a discussion of this theorem, along with the problem of irreversibility.Comprised of 10 chapters, this volume begins with an introduction to the fundamental nature of heat and of gases, along with Boltzmann's work on the kinetic theory of gases and s

  18. Catalytic biomass pyrolysis process

    Science.gov (United States)

    Dayton, David C.; Gupta, Raghubir P.; Turk, Brian S.; Kataria, Atish; Shen, Jian-Ping

    2018-04-17

    Described herein are processes for converting a biomass starting material (such as lignocellulosic materials) into a low oxygen containing, stable liquid intermediate that can be refined to make liquid hydrocarbon fuels. More specifically, the process can be a catalytic biomass pyrolysis process wherein an oxygen removing catalyst is employed in the reactor while the biomass is subjected to pyrolysis conditions. The stream exiting the pyrolysis reactor comprises bio-oil having a low oxygen content, and such stream may be subjected to further steps, such as separation and/or condensation to isolate the bio-oil.

  19. DWPF process control

    International Nuclear Information System (INIS)

    Heckendoin, F.M. II

    1983-01-01

    The Defense Waste Processing Facility (DWPF) for waste vitrification at the Savannah River Plant (SRP) is in the final design stage. Instrumentation to provide the parameter sensing required to assure the quality of the two-foot-diameter, ten-foot-high waste canister is in the final stage of development. All step of the process and instrumentation are now operating as nearly full-scale prototypes at SRP. Quality will be maintained by assuring that only the intended material enters the canisters, and by sensing the resultant condition of the filled canisters. Primary emphasis will be on instrumentation of the process

  20. Advanced uranium enrichment processes

    International Nuclear Information System (INIS)

    Clerc, M.; Plurien, P.

    1986-01-01

    Three advanced Uranium enrichment processes are dealt with in the report: AVLIS (Atomic Vapour LASER Isotope Separation), MLIS (Molecular LASER Isotope Separation) and PSP (Plasma Separation Process). The description of the physical and technical features of the processes constitutes a major part of the report. If further presents comparisons with existing industrially used enrichment technologies, gives information on actual development programmes and budgets and ends with a chapter on perspectives and conclusions. An extensive bibliography of the relevant open literature is added to the different subjects discussed. The report was drawn up by the nuclear research Centre (CEA) Saclay on behalf of the Commission of the European Communities