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Sample records for dual-axis radiographic hydrodynamic

  1. Dual Axis Radiographic Hydrodynamic Test Facility mitigation action plan. Annual report for 1998

    Energy Technology Data Exchange (ETDEWEB)

    Haagenstad, T.

    1999-01-15

    This Mitigation Action Plan Annual Report (MAPAR) has been prepared as part of implementing the Dual Axis Radiographic Hydrodynamic Test Facility (DARHT) Mitigation Action Plan (MAP) to protect workers, soils, water, and biotic and cultural resources in and around the facility.

  2. Dual Axis Radiographic Hydrodynamic Test Facility mitigation action plan. Annual report for 1998

    International Nuclear Information System (INIS)

    Haagenstad, T.

    1999-01-01

    This Mitigation Action Plan Annual Report (MAPAR) has been prepared as part of implementing the Dual Axis Radiographic Hydrodynamic Test Facility (DARHT) Mitigation Action Plan (MAP) to protect workers, soils, water, and biotic and cultural resources in and around the facility

  3. Dual axis radiographic hydrodynamic test facility. Final environmental impact statement, Volume 2: Public comments and responses

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-08-01

    On May 12, 1995, the U.S. Department of Energy (DOE) issued the draft Dual Axis Radiographic Hydrodynamic Test Facility Environmental Impact Statement (DARHT EIS) for review by the State of New Mexico, Indian Tribes, local governments, other Federal agencies, and the general public. DOE invited comments on the accuracy and adequacy of the draft EIS and any other matters pertaining to their environmental reviews. The formal comment period ran for 45 days, to June 26, 1995, although DOE indicated that late comments would be considered to the extent possible. As part of the public comment process, DOE held two public hearings in Los Alamos and Santa Fe, New Mexico, on May 31 and June 1, 1995. In addition, DOE made the draft classified supplement to the DARHT EIS available for review by appropriately cleared individuals with a need to know the classified information. Reviewers of the classified material included the State of New Mexico, the U.S. Environmental Protection Agency, the Department of Defense, and certain Indian Tribes. Volume 2 of the final DARHT EIS contains three chapters. Chapter 1 includes a collective summary of the comments received and DOE`s response. Chapter 2 contains the full text of the public comments on the draft DARHT EIS received by DOE. Chapter 3 contains DOE`s responses to the public comments and an indication as to how the comments were considered in the final EIS.

  4. Dual Axis Radiographic Hydrodynamic Test Facility mitigation action plan. Annual report for 1997

    Energy Technology Data Exchange (ETDEWEB)

    Haagenstad, H.T.

    1998-01-15

    This Mitigation Action Plan Annual Report (MAPAR) has been prepared by the US Department of Energy (DOE) as part of implementing the Dual Axis Radiographic Hydrodynamic Test Facility (DARHT) Mitigation Action Plan (MAP). This MAPAR provides a status on specific DARHT facility design- and construction-related mitigation actions that have been initiated in order to fulfill DOE`s commitments under the DARHT MAP. The functions of the DARHT MAP are to (1) document potentially adverse environmental impacts of the Phased Containment Option delineated in the Final EIS, (2) identify commitments made in the Final EIS and ROD to mitigate those potential impacts, and (3) establish Action Plans to carry out each commitment (DOE 1996). The DARHT MAP is divided into eight sections. Sections 1--5 provide background information regarding the NEPA review of the DARHT project and an introduction to the associated MAP. Section 6 references the Mitigation Action Summary Table which summaries the potential impacts and mitigation measures; indicates whether the mitigation is design-, construction-, or operational-related; the organization responsible for the mitigation measure; and the projected or actual completion data for each mitigation measure. Sections 7 and 8 discuss the Mitigation Action Plan Annual Report and Tracking System commitment and the Potential Impacts, Commitments, and Action Plans respectively. Under Section 8, potential impacts are categorized into five areas of concern: General Environment, including impacts to air and water; Soils, especially impacts affecting soil loss and contamination; Biotic Resources, especially impacts affecting threatened and endangered species; Cultural/Paleontological Resources, especially impacts affecting the archeological site known as Nake`muu; and Human Health and Safety, especially impacts pertaining to noise and radiation. Each potential impact includes a brief statement of the nature of the impact and its cause(s). The commitment

  5. Concentrations of Radionuclides and Trace Elements in Environmantal Media arond te Dual-Axis Radiographic Hydrodynamic Test Facilit at Los Alamos National Laboratory during 2005

    Energy Technology Data Exchange (ETDEWEB)

    G.J.Gonzales; P.R. Fresquez; C.D.Hathcock; D.C. Keller

    2006-05-15

    The Mitigation Action Plan (MAP) for the Dual-Axis Radiographic Hydrodynamic Test (DARHT) facility at Los Alamos National Laboratory requires that samples of biotic and abiotic media be collected after operations began to determine if there are any human health or environmental impacts. The DARHT facility is the Laboratory's principal explosive test facility. To this end, samples of soil and sediment, vegetation, bees, and birds were collected around the facility in 2005 and analyzed for concentrations of {sup 3}H, {sup 137}Cs, {sup 90}Sr, {sup 238}Pu, {sup 239,240}Pu, {sup 241}Am, {sup 234}U, {sup 235}U, {sup 238}U, Ag, As, Ba, Be, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Se, and Tl. Bird populations have also been monitored. Contaminant results, which represent up to six sample years since the start of operations, were compared with (1) baseline statistical reference levels (BSRLs) established over a four-year preoperational period before DARHT facility operations, (2) screening levels (SLs), and (3) regulatory standards. Most radionuclides and trace elements were below BSRLs and those few samples that contained radionuclides and trace elements above BSRLs were below SLs. Concentrations of radionuclides and nonradionuclides in biotic and abiotic media around the DARHT facility do not pose a significant human health hazard. The total number of birds captured and number of species represented were similar in 2003 and 2004, but both of these parameters increased substantially in 2005. Periodic interruption of the scope and schedule identified in the MAP generally should have no impact on meeting the intent of the MAP. The risk of not sampling one of the five media in any given year is that if a significant impact to contaminant levels were to occur there would exist a less complete understanding of the extent of the change to the baseline for these media and to the ecosystem as a whole. Since the MAP is a requirement that was established under the regulatory framework of

  6. Shot H3837: Darht's First Dual-Axis Explosive Experiment

    Science.gov (United States)

    Mendez, Jacob; McNeil, Wendy Vogan; Harsh, James; Hull, Lawrence

    2011-06-01

    Test H3837 was the first explosive shot performed in front of both flash x-ray axes at the Los Alamos Dual Axis Radiographic HydroTest (DARHT) facility. Executed in November 2009, the shot was an explosively-driven metal flyer plate in a series of experiments designed to explore equation-of-state properties of shocked materials. Imaging the initial shock wave traveling through the flyer plate, DARHT Axis II captured the range of motion from the shock front emergence in the flyer to breakout at the free surface; the Axis I pulse provided a perpendicular perspective of the shot at a time coinciding with the third pulse of Axis II. Since the days of the Manhattan Project, penetrating radiography with multiple frames from different viewing angles has remained a high-profile goal at the Laboratory. H3837 is merely the beginning of a bright future for two-axis penetrating radiography.

  7. design and implementation of a microcontroller based dual axis

    African Journals Online (AJOL)

    user

    In this paper, an efficient microcontroller-based dual axis solar radiation tracker which can be used to align a single photovoltaic (PV) ... replaced them with wind turbine generating stations. ... tracker which has both horizontal and vertical axle.

  8. Dual Axis Controller for Extreme Environments, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The Dual Axis Controller for Extreme Environments (DACEE) addresses a critical need of NASA's future exploration plans to investigate extreme environments within our...

  9. Energy Efficient Hybrid Dual Axis Solar Tracking System

    Directory of Open Access Journals (Sweden)

    Rashid Ahammed Ferdaus

    2014-01-01

    Full Text Available This paper describes the design and implementation of an energy efficient solar tracking system from a normal mechanical single axis to a hybrid dual axis. For optimizing the solar tracking mechanism electromechanical systems were evolved through implementation of different evolutional algorithms and methodologies. To present the tracker, a hybrid dual-axis solar tracking system is designed, built, and tested based on both the solar map and light sensor based continuous tracking mechanism. These light sensors also compare the darkness and cloudy and sunny conditions assisting daily tracking. The designed tracker can track sun’s apparent position at different months and seasons; thereby the electrical controlling device requires a real time clock device for guiding the tracking system in seeking solar position for the seasonal motion. So the combination of both of these tracking mechanisms made the designed tracker a hybrid one. The power gain and system power consumption are compared with a static and continuous dual axis solar tracking system. It is found that power gain of hybrid dual axis solar tracking system is almost equal to continuous dual axis solar tracking system, whereas the power saved in system operation by the hybrid tracker is 44.44% compared to the continuous tracking system.

  10. Inductive voltage adder advanced hydrodynamic radiographic technology demonstration

    International Nuclear Information System (INIS)

    Mazarakis, M.G.; Poukey, J.W.; Maenchen; Rovang, D.C.

    1997-04-01

    This paper presents the design, results, and analysis of a high-brightness electron beam technology demonstration experiment completed at Sandia National Laboratories, performed in collaboration with Los Alamos National Laboratory. The anticipated electron beam parameters were: 12 MeV, 35-40 kA, 0.5-mm rms radius, and 40-ns full width half maximum (FWHM) pulse duration. This beam, on an optimum thickness tantalum converter, should produce a very intense x-ray source of ∼ 1.5-mm spot size and 1 kR dose at sign 1 m. The accelerator utilized was SABRE, a pulsed inductive voltage adder, and the electron source was a magnetically immersed foilless electron diode. For these experiments, SABRE was modified to high-impedance negative-polarity operation. A new 100-ohm magnetically insulated transmission line cathode electrode was designed and constructed; the cavities were rotated 180 degrees poloidally to invert the central electrode polarity to negative; and only one of the two pulse forming lines per cavity was energized. A twenty- to thirty-Tesla solenoidal magnet insulated the diode and contained the beam at its extremely small size. These experiments were designed to demonstrate high electron currents in submillimeter radius beams resulting in a high-brightness high-intensity flash x-ray source for high-resolution thick-object hydrodynamic radiography. The SABRE facility high-impedance performance was less than what was hoped. The modifications resulted in a lower amplitude (9 MV), narrower-than-anticipated triangular voltage pulse, which limited the dose to ∼ 20% of the expected value. In addition, halo and ion-hose instabilities increased the electron beam spot size to > 1.5 mm. Subsequent, more detailed calculations explain these reduced output parameters. An accelerator designed (versus retrofit) for this purpose would provide the desired voltage and pulse shape

  11. A procedure for denoising dual-axis swallowing accelerometry signals

    International Nuclear Information System (INIS)

    Sejdić, Ervin; Chau, Tom; Steele, Catriona M

    2010-01-01

    Dual-axis swallowing accelerometry is an emerging tool for the assessment of dysphagia (swallowing difficulties). These signals however can be very noisy as a result of physiological and motion artifacts. In this note, we propose a novel scheme for denoising those signals, i.e. a computationally efficient search for the optimal denoising threshold within a reduced wavelet subspace. To determine a viable subspace, the algorithm relies on the minimum value of the estimated upper bound for the reconstruction error. A numerical analysis of the proposed scheme using synthetic test signals demonstrated that the proposed scheme is computationally more efficient than minimum noiseless description length (MNDL)-based denoising. It also yields smaller reconstruction errors than MNDL, SURE and Donoho denoising methods. When applied to dual-axis swallowing accelerometry signals, the proposed scheme exhibits improved performance for dry, wet and wet chin tuck swallows. These results are important for the further development of medical devices based on dual-axis swallowing accelerometry signals. (note)

  12. Annual Report: Hydrodynamics and Radiative Hydrodynamics with Astrophysical Applications

    Energy Technology Data Exchange (ETDEWEB)

    R. Paul Drake

    2005-12-01

    We report the ongoing work of our group in hydrodynamics and radiative hydrodynamics with astrophysical applications. During the period of the existing grant, we have carried out two types of experiments at the Omega laser. One set of experiments has studied radiatively collapsing shocks, obtaining high-quality scaling data using a backlit pinhole and obtaining the first (ever, anywhere) Thomson-scattering data from a radiative shock. Other experiments have studied the deeply nonlinear development of the Rayleigh-Taylor (RT) instability from complex initial conditions, obtaining the first (ever, anywhere) dual-axis radiographic data using backlit pinholes and ungated detectors. All these experiments have applications to astrophysics, discussed in the corresponding papers either in print or in preparation. We also have obtained preliminary radiographs of experimental targets using our x-ray source. The targets for the experiments have been assembled at Michigan, where we also prepare many of the simple components. The above activities, in addition to a variety of data analysis and design projects, provide good experience for graduate and undergraduates students. In the process of doing this research we have built a research group that uses such work to train junior scientists.

  13. Design and fabrication of an automatic dual axis solar tracker by ...

    African Journals Online (AJOL)

    International Journal of Engineering, Science and Technology. Vol. 9, No. 2, 2017, pp. ... All rights reserved. Design and fabrication of an automatic dual axis solar tracker by using LDR ..... It may be like a wiper of the car. Nomenclature. LDR.

  14. Design, Fabrication, and Modeling of a Novel Dual-Axis Control Input PZT Gyroscope.

    Science.gov (United States)

    Chang, Cheng-Yang; Chen, Tsung-Lin

    2017-10-31

    Conventional gyroscopes are equipped with a single-axis control input, limiting their performance. Although researchers have proposed control algorithms with dual-axis control inputs to improve gyroscope performance, most have verified the control algorithms through numerical simulations because they lacked practical devices with dual-axis control inputs. The aim of this study was to design a piezoelectric gyroscope equipped with a dual-axis control input so that researchers may experimentally verify those control algorithms in future. Designing a piezoelectric gyroscope with a dual-axis control input is more difficult than designing a conventional gyroscope because the control input must be effective over a broad frequency range to compensate for imperfections, and the multiple mode shapes in flexural deformations complicate the relation between flexural deformation and the proof mass position. This study solved these problems by using a lead zirconate titanate (PZT) material, introducing additional electrodes for shielding, developing an optimal electrode pattern, and performing calibrations of undesired couplings. The results indicated that the fabricated device could be operated at 5.5±1 kHz to perform dual-axis actuations and position measurements. The calibration of the fabricated device was completed by system identifications of a new dynamic model including gyroscopic motions, electromechanical coupling, mechanical coupling, electrostatic coupling, and capacitive output impedance. Finally, without the assistance of control algorithms, the "open loop sensitivity" of the fabricated gyroscope was 1.82 μV/deg/s with a nonlinearity of 9.5% full-scale output. This sensitivity is comparable with those of other PZT gyroscopes with single-axis control inputs.

  15. Design, Fabrication, and Modeling of a Novel Dual-Axis Control Input PZT Gyroscope

    Directory of Open Access Journals (Sweden)

    Cheng-Yang Chang

    2017-10-01

    Full Text Available Conventional gyroscopes are equipped with a single-axis control input, limiting their performance. Although researchers have proposed control algorithms with dual-axis control inputs to improve gyroscope performance, most have verified the control algorithms through numerical simulations because they lacked practical devices with dual-axis control inputs. The aim of this study was to design a piezoelectric gyroscope equipped with a dual-axis control input so that researchers may experimentally verify those control algorithms in future. Designing a piezoelectric gyroscope with a dual-axis control input is more difficult than designing a conventional gyroscope because the control input must be effective over a broad frequency range to compensate for imperfections, and the multiple mode shapes in flexural deformations complicate the relation between flexural deformation and the proof mass position. This study solved these problems by using a lead zirconate titanate (PZT material, introducing additional electrodes for shielding, developing an optimal electrode pattern, and performing calibrations of undesired couplings. The results indicated that the fabricated device could be operated at 5.5±1 kHz to perform dual-axis actuations and position measurements. The calibration of the fabricated device was completed by system identifications of a new dynamic model including gyroscopic motions, electromechanical coupling, mechanical coupling, electrostatic coupling, and capacitive output impedance. Finally, without the assistance of control algorithms, the “open loop sensitivity” of the fabricated gyroscope was 1.82 μV/deg/s with a nonlinearity of 9.5% full-scale output. This sensitivity is comparable with those of other PZT gyroscopes with single-axis control inputs.

  16. Design of a dual-axis optoelectronic level for precision angle measurements

    International Nuclear Information System (INIS)

    Fan, Kuang-Chao; Wang, Tsung-Han; Lin, Sheng-Yi; Liu, Yen-Chih

    2011-01-01

    The accuracy of machine tools is mainly determined by angular errors during linear motion according to the well-known Abbe principle. Precision angle measurement is important to precision machines. This paper presents the theory and experiments of a new dual-axis optoelectronic level with low cost and high precision. The system adopts a commercial DVD pickup head as the angle sensor in association with the double-layer pendulum mechanism for two-axis swings, respectively. In data processing with a microprocessor, the measured angles of both axes can be displayed on an LCD or exported to an external PC. Calibrated by a triple-beam laser angular interferometer, the error of the dual-axis optoelectronic level is better than ±0.7 arcsec in the measuring range of ±30 arcsec, and the settling time is within 0.5 s. Experiments show the applicability to the inspection of precision machines

  17. The dual-axis solar tracking system efficiency improving via the drive power consumption optimization

    International Nuclear Information System (INIS)

    Rambhowan, Y.; Oree, V.

    2014-01-01

    A major drawback with active dual-axis solar tracking systems is that the power used by the driving mechanism is often drawn from the output power of the solar panel itself. The net energy gain of the photo-voltaic panel is therefore less than its maximum value. This work presents a novel design which uses a three-fold strategy to minimize the power consumed by the tracking mechanism whilst maintaining the power out-put of the photovoltaic panel near its optimal value. The results reveal that the improved tracking system has a significant energy gain of about 43.6% as compared to a fixed photovoltaic panel. Experiments further show that an increase of 1.6% in energy output is achieved over conventional precise dual-axis tracking system. (author)

  18. Automated positioning dual-axis solar tracking system with precision elevation and azimuth angle control

    International Nuclear Information System (INIS)

    Sidek, M.H.M.; Azis, N.; Hasan, W.Z.W.; Ab Kadir, M.Z.A.; Shafie, S.; Radzi, M.A.M.

    2017-01-01

    This paper presents a study on an automated positioning open-loop dual-axis solar tracking system. The solar tracker was designed and fabricated using standard cylindrical aluminium hollow and Polyuthrene (PE). The control system of the solar tracker was governed by Micro Controller Unit (MCU) with auxiliary devices which includes encoder and Global Positioning System (GPS). The sun path trajectory algorithm utilizing the astronomical equation and GPS information was also embedded in the system. The power generation performance of the dual-axis solar tracking system was compared with the fixed-tilted Photovoltaic (PV) system. It is found that the solar tracker is able to position itself automatically based on sun path trajectory algorithm with an accuracy of ±0.5°. The embedded Proportional Integral Derivative (PID) positioning system improves the tracking of elevation and azimuth angles with minimum energy consumption. It is reveals that the proposed solar tracker is able generate 26.9% and 12.8% higher power than fixed-tilted PV system on a clear and heavy overcast conditions respectively. Overall, the open-loop dual-axis solar tracker can be deployed automatically at any location on the earth with minimal configurations and is suitable for mobile solar tracking system. - Highlights: • Self-positioning dual-axis solar tracking system. • Precise control of elevation and azimuth angle. • Sun path trajectory based on astronomical equation and GPS. • Can achieve up to 26.9% higher power than fixed-tilted PV system under clear weather condition.

  19. Mechanical design and force calibration of dual-axis micromechanical probe for friction force microscopy

    International Nuclear Information System (INIS)

    Fukuzawa, Kenji; Terada, Satoshi; Shikida, Mitsuhiro; Amakawa, Hiroaki; Zhang, Hedong; Mitsuya, Yasunaga

    2007-01-01

    A dual-axis micromechanical probe that combines a double cantilever and torsion beams is presented. This probe can reduce the mechanical cross-talk between the lateral and vertical force detections. In addition, dual-axis forces can be detected by measuring the dual-axis displacement of the probe end using the optical lever-based method used in conventional friction force microscopes (FFMs). In this paper, the mechanical design of the probe, the details of the fabrication method, FFM performance, and calibration of the friction force are discussed. The mechanical design and the microfabrication method for probes that can provide a force resolution of the order of 1 nN without mechanical cross-talk are presented. Calibration of the lateral force signal is possible by using the relationship between the lateral force and the piezodisplacement at the onset of the probe scanning. The micromechanical probe enables simultaneous and independent detection of atomic and friction forces. This leads to accurate investigation of nanotribological phenomena and visualization of the distribution of the friction properties, which helps the identification of the material properties

  20. Commissioning of the advanced light source dual-axis streak camera

    International Nuclear Information System (INIS)

    Hinkson, J.; Keller, R.; Byrd, J.

    1997-05-01

    A dual-axis camera, Hamamatsu model C5680, has been installed on the Advanced Light Source photon-diagnostics beam-line to investigate electron-beam parameters. During its commissioning process, the camera has been used to measure single-bunch length vs. current, relative bunch charge in adjacent RF buckets, and bunchphase stability. In this paper the authors describe the visible-light branch of the diagnostics beam-line, the streak-camera installation, and the timing electronics. They will show graphical results of beam measurements taken during a variety of accelerator conditions

  1. Annual Scientific Report 2006 for Hydrodynamics and Radiation Hydrodynamics with Astrophysical Applications

    International Nuclear Information System (INIS)

    R. Paul Drake

    2007-01-01

    We report the ongoing work of our group in hydrodynamics and radiation hydrodynamics with astrophysical applications. During the period of the existing grant, we have carried out two types of experiments at the Omega laser. One set of experiments has studied radiatively collapsing shocks, obtaining data using a backlit pinhole with a 100 ps backlighter and beginning to develop the ability to look into the shock tube with optical or x-ray diagnostics. Other experiments have studied the deeply nonlinear development of the Rayleigh-Taylor (RT) instability from complex initial conditions, using dual-axis radiographic data with backlit pinholes and ungated detectors to complete the data set for a Ph.D. student. We lead a team that is developing a proposal for experiments at the National Ignition Facility and are involved in experiments at NIKE and LIL. All these experiments have applications to astrophysics, discussed in the corresponding papers. We assemble the targets for the experiments at Michigan, where we also prepare many of the simple components. We also have several projects underway in our laboratory involving our x-ray source. The above activities, in addition to a variety of data analysis and design projects, provide good experience for graduate and undergraduates students. In the process of doing this research we have built a research group that uses such work to train junior scientists

  2. Annual Report 2006 for Hydrodynamics and Radiation Hydrodynamics with Astrophysical Applications

    Energy Technology Data Exchange (ETDEWEB)

    R. Paul Drake

    2007-04-05

    We report the ongoing work of our group in hydrodynamics and radiation hydrodynamics with astrophysical applications. During the period of the existing grant, we have carried out two types of experiments at the Omega laser. One set of experiments has studied radiatively collapsing shocks, obtaining data using a backlit pinhole with a 100 ps backlighter and beginning to develop the ability to look into the shock tube with optical or x-ray diagnostics. Other experiments have studied the deeply nonlinear development of the Rayleigh-Taylor (RT) instability from complex initial conditions, using dual-axis radiographic data with backlit pinholes and ungated detectors to complete the data set for a Ph.D. student. We lead a team that is developing a proposal for experiments at the National Ignition Facility and are involved in experiments at NIKE and LIL. All these experiments have applications to astrophysics, discussed in the corresponding papers. We assemble the targets for the experiments at Michigan, where we also prepare many of the simple components. We also have several projects underway in our laboratory involving our x-ray source. The above activities, in addition to a variety of data analysis and design projects, provide good experience for graduate and undergraduates students. In the process of doing this research we have built a research group that uses such work to train junior scientists.

  3. Performance Evaluation of Dual-axis Tracking System of Parabolic Trough Solar Collector

    Science.gov (United States)

    Ullah, Fahim; Min, Kang

    2018-01-01

    A parabolic trough solar collector with the concentration ratio of 24 was developed in the College of Engineering; Nanjing Agricultural University, China with the using of the TracePro software an optical model built. Effects of single-axis and dual-axis tracking modes, azimuth and elevating angle tracking errors on the optical performance were investigated and the thermal performance of the solar collector was experimentally measured. The results showed that the optical efficiency of the dual-axis tracking was 0.813% and its year average value was 14.3% and 40.9% higher than that of the eat-west tracking mode and north-south tracking mode respectively. Further, form the results of the experiment, it was concluded that the optical efficiency was affected significantly by the elevation angle tracking errors which should be kept below 0.6o. High optical efficiency could be attained by using dual-tracking mode even though the tracking precision of one axis was degraded. The real-time instantaneous thermal efficiency of the collector reached to 0.775%. In addition, the linearity of the normalized efficiency was favorable. The curve of the calculated thermal efficiency agreed well with the normalized instantaneous efficiency curve derived from the experimental data and the maximum difference between them was 10.3%. This type of solar collector should be applied in middle-scale thermal collection systems.

  4. Development of Dual-Axis MEMS Accelerometers for Machine Tools Vibration Monitoring

    Directory of Open Access Journals (Sweden)

    Chih-Yung Huang

    2016-07-01

    Full Text Available With the development of intelligent machine tools, monitoring the vibration by the accelerometer is an important issue. Accelerometers used for measuring vibration signals during milling processes require the characteristics of high sensitivity, high resolution, and high bandwidth. A commonly used accelerometer is the lead zirconate titanate (PZT type; however, integrating it into intelligent modules is excessively expensive and difficult. Therefore, the micro electro mechanical systems (MEMS accelerometer is an alternative with the advantages of lower price and superior integration. In the present study, we integrated two MEMS accelerometer chips into a low-pass filter and housing to develop a low-cost dual-axis accelerometer with a bandwidth of 5 kHz and a full scale range of ±50 g for measuring machine tool vibration. In addition, a platform for measuring the linearity, cross-axis sensitivity and frequency response of the MEMS accelerometer by using the back-to-back calibration method was also developed. Finally, cutting experiments with steady and chatter cutting were performed to verify the results of comparing the MEMS accelerometer with the PZT accelerometer in the time and frequency domains. The results demonstrated that the dual-axis MEMS accelerometer is suitable for monitoring the vibration of machine tools at low cost.

  5. High-accuracy self-calibration method for dual-axis rotation-modulating RLG-INS

    Science.gov (United States)

    Wei, Guo; Gao, Chunfeng; Wang, Qi; Wang, Qun; Long, Xingwu

    2017-05-01

    Inertial navigation system has been the core component of both military and civil navigation systems. Dual-axis rotation modulation can completely eliminate the inertial elements constant errors of the three axes to improve the system accuracy. But the error caused by the misalignment angles and the scale factor error cannot be eliminated through dual-axis rotation modulation. And discrete calibration method cannot fulfill requirements of high-accurate calibration of the mechanically dithered ring laser gyroscope navigation system with shock absorbers. This paper has analyzed the effect of calibration error during one modulated period and presented a new systematic self-calibration method for dual-axis rotation-modulating RLG-INS. Procedure for self-calibration of dual-axis rotation-modulating RLG-INS has been designed. The results of self-calibration simulation experiment proved that: this scheme can estimate all the errors in the calibration error model, the calibration precision of the inertial sensors scale factor error is less than 1ppm and the misalignment is less than 5″. These results have validated the systematic self-calibration method and proved its importance for accuracy improvement of dual -axis rotation inertial navigation system with mechanically dithered ring laser gyroscope.

  6. Dual axis translation apparatus and system for translating an optical beam and related method

    Science.gov (United States)

    Cassidy, Kelly

    1991-01-01

    A dual axis translation device and system in accordance with this invention, for translating an optical beam along both an x-axis and a y-axis which are perpendicular to one another, has a beam directing means acting on said optical beam for directing the beam along a particular path transverse to said x and y axes. An arrangement supporting said beam directing means for movement in the x and y direction within a given plane is provided. The arrangement includes a first means for translating said beam directing means along the x-axis in said given plane in order to translate the beam along said x-axis. The arrangement comprises a second means for translating said beam directing means along the y-axis in said given plane in order to translate the beam along said y-axis.

  7. Dual-axis vapor cell for simultaneous laser frequency stabilization on disparate optical transitions

    Science.gov (United States)

    Jayakumar, Anupriya; Plotkin-Swing, Benjamin; Jamison, Alan O.; Gupta, Subhadeep

    2015-07-01

    We have developed a dual-axis ytterbium (Yb) vapor cell and used it to simultaneously address the two laser cooling transitions in Yb at wavelengths 399 nm and 556 nm, featuring the disparate linewidths of 2π × 29 MHz and 2π × 182 KHz, respectively. By utilizing different optical paths for the two wavelengths, we simultaneously obtain comparable optical densities suitable for saturated absorption spectroscopy for both the transitions and keep both the lasers frequency stabilized over several hours. We demonstrate that by appropriate control of the cell temperature profile, two atomic transitions differing in relative strength across a large range of over three orders of magnitude can be simultaneously addressed, making the device adaptable to a variety of spectroscopic needs. We also show that our observations can be understood with a simple theoretical model of the Yb vapor.

  8. Dual-axis vapor cell for simultaneous laser frequency stabilization on disparate optical transitions

    Energy Technology Data Exchange (ETDEWEB)

    Jayakumar, Anupriya, E-mail: anupriya@uw.edu; Plotkin-Swing, Benjamin; Jamison, Alan O.; Gupta, Subhadeep [Department of Physics, University of Washington, P.O. Box 351560, Seattle, Washington 98195-1560 (United States)

    2015-07-15

    We have developed a dual-axis ytterbium (Yb) vapor cell and used it to simultaneously address the two laser cooling transitions in Yb at wavelengths 399 nm and 556 nm, featuring the disparate linewidths of 2π × 29 MHz and 2π × 182 KHz, respectively. By utilizing different optical paths for the two wavelengths, we simultaneously obtain comparable optical densities suitable for saturated absorption spectroscopy for both the transitions and keep both the lasers frequency stabilized over several hours. We demonstrate that by appropriate control of the cell temperature profile, two atomic transitions differing in relative strength across a large range of over three orders of magnitude can be simultaneously addressed, making the device adaptable to a variety of spectroscopic needs. We also show that our observations can be understood with a simple theoretical model of the Yb vapor.

  9. Experimental studies of 7-cell dual axis asymmetric cavity for energy recovery linac

    Directory of Open Access Journals (Sweden)

    I. V. Konoplev

    2017-10-01

    Full Text Available High average current, transportable energy recovery linacs (ERLs can be very attractive tools for a number of applications including next generation high-luminosity, compact light sources. Conventional ERLs are based on an electron beam circulating through the same set of rf cavity cells. This leads to an accumulation of high-order modes inside the cavity cells, resulting in the development of a beam breakup (BBU instability, unless the beam current is kept below the BBU start current. This limits the maximum current which can be transported through the ERL and hence the intensity of the photon beam generated. It has recently been proposed that splitting the accelerating and decelerating stages, tuning them separately and coupling them via a resonance coupler can increase the BBU start current. The paper presents the first experimental rf studies of a dual axis 7-cell asymmetric cavity and confirms the properties predicted by the theoretical model. The field structures of the symmetric and asymmetric modes are measured and good agreement with the numerical predictions is demonstrated. The operating mode field flatness was also measured and discussed. A novel approach based on the coupled mode (Fano-like model has been developed for the description of the cavity eigenmode spectrum and good agreement between analytical theory, numerical predictions and experimental data is shown. Numerical and experimental results observed are analyzed, discussed and a good agreement between theory and experiment is demonstrated.

  10. Dual-Axis Solar Tracking System for Maximum Power Production in PV Systems

    Directory of Open Access Journals (Sweden)

    Muhd.Ikram Mohd. Rashid

    2015-12-01

    Full Text Available The power developed in a solar energy system depends fundamentally upon the amount of sunlight captured by the photovoltaic modules/arrays. This paper describes a simple electro-mechanical dual axis solar tracking system designed and developed in a study. The control of the two axes was achieved by the pulses generated from the data acquisition (DAQ card fed into four relays. This approach was so chosen to effectively avoid the error that usually arises in sensor-based methods. The programming of the mathematical models of the solar elevation and azimuth angles was done using Borland C++ Builder. The performance and accuracy of the developed system was evaluated with a PV panel at latitude 3.53o N and longitude 103.5o W in Malaysia. The results obtained reflect the effectiveness of the developed tracking system in terms of the energy yield when compared with that generated from a fixed panel. Overall, 20%, 23% and 21% additional energy were produced for the months of March, April and May respectively using the tracker developed in this study.

  11. In vivo near-infrared dual-axis confocal microendoscopy in the human lower gastrointestinal tract

    Science.gov (United States)

    Piyawattanametha, Wibool; Ra, Hyejun; Qiu, Zhen; Friedland, Shai; Liu, Jonathan T. C.; Loewke, Kevin; Kino, Gordon S.; Solgaard, Olav; Wang, Thomas D.; Mandella, Michael J.; Contag, Christopher H.

    2012-02-01

    Near-infrared confocal microendoscopy is a promising technique for deep in vivo imaging of tissues and can generate high-resolution cross-sectional images at the micron-scale. We demonstrate the use of a dual-axis confocal (DAC) near-infrared fluorescence microendoscope with a 5.5-mm outer diameter for obtaining clinical images of human colorectal mucosa. High-speed two-dimensional en face scanning was achieved through a microelectromechanical systems (MEMS) scanner while a micromotor was used for adjusting the axial focus. In vivo images of human patients are collected at 5 frames/sec with a field of view of 362×212 μm2 and a maximum imaging depth of 140 μm. During routine endoscopy, indocyanine green (ICG) was topically applied a nonspecific optical contrasting agent to regions of the human colon. The DAC microendoscope was then used to obtain microanatomic images of the mucosa by detecting near-infrared fluorescence from ICG. These results suggest that DAC microendoscopy may have utility for visualizing the anatomical and, perhaps, functional changes associated with colorectal pathology for the early detection of colorectal cancer.

  12. Conception and realization of a PV system provided with a sun tracker operating at dual axis

    Directory of Open Access Journals (Sweden)

    Khalil Kassmi

    2016-06-01

    Full Text Available In this paper, we present the conception, the realization and the experimentation of  a photovoltaic (PV system provided with a sun tracker reliable and low cost operating at dual axis. The tracker's role is to orient the PV generator, whose weight may reach 9 Kg, perpendicular to the sun with very good accuracy. This tracking  based on the use of four LDR sensors, which detect the intensity of light scattered by the sun a processing unit, from  command and control (UTCC, which manages all of the sun tracking tasks (the end detection of parcours, regulation of the power supplied by the PV panels (Command MPPT, ... . The results obtained show a significant improvement of the energy produced, compared to conventional PV installations where generators are fixed and oriented south at a  tilt 45°. During a day of operation, improvement could reach 41% and consumption of the tracking does not exceed 0.55% of the energy production produced by the PV generator (an improvement of 5 % compared to existing trackers.

  13. Evaluation of optimal dual axis concentrated photovoltaic thermal system with active ventilation using Frog Leap algorithm

    International Nuclear Information System (INIS)

    Gholami, H.; Sarwat, A.I.; Hosseinian, H.; Khalilnejad, A.

    2015-01-01

    Highlights: • Electro-thermal performance of open-loop controlled dual axis CPVT is investigated. • For using the absorbed heat, active ventilation with a heat storage tank is used. • Economic optimization of the system is performed, using Frog Leap algorithm. • Detailed model of all sections is simulated with their characteristics evaluation. • Triple-junction photovoltaic cells, which are the most recent technology, are used. - Abstract: In this study, design and optimization of a concentrated photovoltaic thermal (CPVT) system considering electrical, mechanical, and economical aspects is investigated. For this purpose, each section of the system is simulated in MATLAB, in detail. Triple-junction photovoltaic cells, which are the most recent technology, are used in this study. They are more efficient in comparison to conventional photovoltaic cells. Unlike ordinary procedures, in this work active ventilation is used for absorbing the thermal power of radiation, using heat storage tanks, which not only results in increasing the electrical efficiency of the system through decreasing the temperature, but also leads to storing and managing produced thermal energy and increasing the total efficiency of the system up to 85 percent. The operation of the CPVT system is investigated for total hours of the year, considering the needed thermal load, meteorological conditions, and hourly radiation of Khuznin, a city in Qazvin province, Iran. Finally, the collector used for this system is optimized economically, using frog leap algorithm, which resulted in the cost of 13.4 $/m"2 for a collector with the optimal distance between tubes of 6.34 cm.

  14. A feasibility study of stationary and dual-axis tracking grid-connected photovoltaic systems in the Upper Midwest

    Science.gov (United States)

    Warren, Ryan Duwain

    Three primary objectives were defined for this work. The first objective was to determine, assess, and compare the performance, heat transfer characteristics, economics, and feasibility of real-world stationary and dual-axis tracking grid-connected photovoltaic (PV) systems in the Upper Midwest. This objective was achieved by installing two grid-connected PV systems with different mounting schemes in central Iowa, implementing extensive data acquisition systems, monitoring operation of the PV systems for one full year, and performing detailed experimental performance and economic studies. The two PV systems that were installed, monitored, and analyzed included a 4.59 kWp roof-mounted stationary system oriented for maximum annual energy production, and a 1.02 kWp pole-mounted actively controlled dual-axis tracking system. The second objective was to demonstrate the actual use and performance of real-world stationary and dual-axis tracking grid-connected PV systems used for building energy generation applications. This objective was achieved by offering the installed PV systems to the public for demonstration purposes and through the development of three computer-based tools: a software interface that has the ability to display real-time and historical performance and meteorological data of both systems side-by-side, a software interface that shows real-time and historical video and photographs of each system, and a calculator that can predict performance and economics of stationary and dual-axis tracking grid-connected PV systems at various locations in the United States. The final objective was to disseminate this work to social, professional, scientific, and academic communities in a way that is applicable, objective, accurate, accessible, and comprehensible. This final objective will be addressed by publishing the results of this work and making the computer-based tools available on a public website (www.energy.iastate.edu/Renewable/solar). Detailed experimental

  15. Novel high accurate sensorless dual-axis solar tracking system controlled by maximum power point tracking unit of photovoltaic systems

    International Nuclear Information System (INIS)

    Fathabadi, Hassan

    2016-01-01

    Highlights: • Novel high accurate sensorless dual-axis solar tracker. • It has the advantages of both sensor based and sensorless solar trackers. • It does not have the disadvantages of sensor based and sensorless solar trackers. • Tracking error of only 0.11° that is less than the tracking errors of others. • An increase of 28.8–43.6% depending on the seasons in the energy efficiency. - Abstract: In this study, a novel high accurate sensorless dual-axis solar tracker controlled by the maximum power point tracking unit available in almost all photovoltaic systems is proposed. The maximum power point tracking controller continuously calculates the maximum output power of the photovoltaic module/panel/array, and uses the altitude and azimuth angles deviations to track the sun direction where the greatest value of the maximum output power is extracted. Unlike all other sensorless solar trackers, the proposed solar tracking system is a closed loop system which means it uses the actual direction of the sun at any time to track the sun direction, and this is the contribution of this work. The proposed solar tracker has the advantages of both sensor based and sensorless dual-axis solar trackers, but it does not have their disadvantages. Other sensorless solar trackers all are open loop, i.e., they use offline estimated data about the sun path in the sky obtained from solar map equations, so low exactness, cloudy sky, and requiring new data for new location are their problems. A photovoltaic system has been built, and it is experimentally verified that the proposed solar tracking system tracks the sun direction with the tracking error of 0.11° which is less than the tracking errors of other both sensor based and sensorless solar trackers. An increase of 28.8–43.6% depending on the seasons in the energy efficiency is the main advantage of utilizing the proposed solar tracking system.

  16. The clinical safety of dual axis rotational angiography in the diagnosis of coronary artery disease

    International Nuclear Information System (INIS)

    Liu Huiliang; Jin Zhigeng; Yang Shengli; Ma Dongxing; Luo Jianping; Liu Ying; Wang Lei; Jing Limin; Meng Rongying

    2011-01-01

    Objective: To observe the clinical safety of dual axis rotational coronary angiography (DARCA) in the diagnosis of coronary artery disease in Chinese population. Methods: From March to December in 2010, 74 patients undergoing diagnostic DARCA were enrolled. The improved isocentering technique was adopted in 34 of the patients at the end of the study during DARCA. Blood pressure, heart rate and symptoms were recorded immediately before-and-after contrast injections. Contrast dose, radiation exposure and procedure time for DARCA were recorded. Continuous variable data were analyzed using Student's t test, if normality assumption was violated, rank sum test would be used. Categorical variables were analyzed using χ 2 test. Results: (1) Clinical safety: There was no chest pain documented during or immediately post-injection for all patients. Only 1 patient (1%) had an attack of ventricular tachycardia immediately after the contrast injection and then relieved automatically. Pre and post-injection systolic blood pressure values of left coronary artery were statistically different [(116±20) mm Hg vs. (111± 18) mm Hg (1 mm Hg = 0.133 kPa), t=3.303, P=0.001], and heart rates differed, too [73 (65- 84) bpm vs. 71 (64-78) bpm, Z=-4.789, P=0.001], but that imposed no clinical significance. (2) Contrast dose, radiation dose and procedure time: The mean contrast utilization, radiation dose and procedure time for DARCA were 28 (25-34) ml, 8979 (6733-12363) mGycm 2 and 200 (164-270) s. Compared with conventional DARCA, improved isocentering technique during DARCA had less radiation exposure and procedure time in left coronary artery angiography and the whole coronary artery angiography left coronary artery angiographic radiation exposure: 4004 (2932-5772) mGycm 2 vs, 5808 (4798- 8838) mGycm 2 , Z=-3.471, P=0.001; total radiation exposure: (8116±2493) mGycm 2 vs. (11371± 4122) mGycm 2 , t=-4.176, P=0.001; left coronary artery angiographic procedure time: 120 (80- 180)s vs

  17. Miniature in vivo MEMS-based line-scanned dual-axis confocal microscope for point-of-care pathology

    Science.gov (United States)

    Yin, C.; Glaser, A.K.; Leigh, S. Y.; Chen, Y.; Wei, L.; Pillai, P. C. S.; Rosenberg, M. C.; Abeytunge, S.; Peterson, G.; Glazowski, C.; Sanai, N.; Mandella, M. J.; Rajadhyaksha, M.; Liu, J. T. C.

    2016-01-01

    There is a need for miniature optical-sectioning microscopes to enable in vivo interrogation of tissues as a real-time and noninvasive alternative to gold-standard histopathology. Such devices could have a transformative impact for the early detection of cancer as well as for guiding tumor-resection procedures. Miniature confocal microscopes have been developed by various researchers and corporations to enable optical sectioning of highly scattering tissues, all of which have necessitated various trade-offs in size, speed, depth selectivity, field of view, resolution, image contrast, and sensitivity. In this study, a miniature line-scanned (LS) dual-axis confocal (DAC) microscope, with a 12-mm diameter distal tip, has been developed for clinical point-of-care pathology. The dual-axis architecture has demonstrated an advantage over the conventional single-axis confocal configuration for reducing background noise from out-of-focus and multiply scattered light. The use of line scanning enables fast frame rates (16 frames/sec is demonstrated here, but faster rates are possible), which mitigates motion artifacts of a hand-held device during clinical use. We have developed a method to actively align the illumination and collection beams in a DAC microscope through the use of a pair of rotatable alignment mirrors. Incorporation of a custom objective lens, with a small form factor for in vivo clinical use, enables our device to achieve an optical-sectioning thickness and lateral resolution of 2.0 and 1.1 microns respectively. Validation measurements with reflective targets, as well as in vivo and ex vivo images of tissues, demonstrate the clinical potential of this high-speed optical-sectioning microscopy device. PMID:26977337

  18. Performance of Dual-Axis Solar Tracker versus Static Solar System by Segmented Clearness Index in Malaysia

    Directory of Open Access Journals (Sweden)

    Jhee Fhong Lee

    2013-01-01

    Full Text Available The performance of Dual-Axis Solar Tracker (DAST and Static Solar System (SSS with respect to clearness index in Malaysia is presented. An attempt to investigate the correlation between clearness index with energy gain and efficiency of DAST over SSS is being done experimentally. A good correlation could not be found out from the daily clearness index. It is due to the more profound advantage of DAST in the morning and evening compared to midday as it is able to follow the sun’s position. Hence, the daily clearness index is divided into three segments which are morning, midday, and evening to interpret the energy gain and efficiency better. A clearer correlation with low standard deviation can be observed on the segmented clearness index analysis. The energy gain and efficiency of seven cities in Malaysia is being estimated with the segmented clearness index and compared to the result generated from anisotropic radiation model. A similar trend is obtained and it has shown that the segmented clearness index could be utilized as a graphical method for estimation of energy gain and efficiency of DAST over SSS.

  19. Gabor-domain optical coherence microscopy with integrated dual-axis MEMS scanner for fast 3D imaging and metrology

    Science.gov (United States)

    Canavesi, Cristina; Cogliati, Andrea; Hayes, Adam; Santhanam, Anand P.; Tankam, Patrice; Rolland, Jannick P.

    2015-10-01

    Fast, robust, nondestructive 3D imaging is needed for characterization of microscopic structures in industrial and clinical applications. A custom micro-electromechanical system (MEMS)-based 2D scanner system was developed to achieve 55 kHz A-scan acquisition in a Gabor-domain optical coherence microscopy (GD-OCM) instrument with a novel multilevel GPU architecture for high-speed imaging. GD-OCM yields high-definition volumetric imaging with dynamic depth of focusing through a bio-inspired liquid lens-based microscope design, which has no moving parts and is suitable for use in a manufacturing setting or in a medical environment. A dual-axis MEMS mirror was chosen to replace two single-axis galvanometer mirrors; as a result, the astigmatism caused by the mismatch between the optical pupil and the scanning location was eliminated and a 12x reduction in volume of the scanning system was achieved. Imaging at an invariant resolution of 2 μm was demonstrated throughout a volume of 1 × 1 × 0.6 mm3, acquired in less than 2 minutes. The MEMS-based scanner resulted in improved image quality, increased robustness and lighter weight of the system - all factors that are critical for on-field deployment. A custom integrated feedback system consisting of a laser diode and a position-sensing detector was developed to investigate the impact of the resonant frequency of the MEMS and the driving signal of the scanner on the movement of the mirror. Results on the metrology of manufactured materials and characterization of tissue samples with GD-OCM are presented.

  20. Design and implementation of a Sun tracker with a dual-axis single motor for an optical sensor-based photovoltaic system.

    Science.gov (United States)

    Wang, Jing-Min; Lu, Chia-Liang

    2013-03-06

    The dual threats of energy depletion and global warming place the development of methods for harnessing renewable energy resources at the center of public interest. Solar energy is one of the most promising renewable energy resources. Sun trackers can substantially improve the electricity production of a photovoltaic (PV) system. This paper proposes a novel design of a dual-axis solar tracking PV system which utilizes the feedback control theory along with a four-quadrant light dependent resistor (LDR) sensor and simple electronic circuits to provide robust system performance. The proposed system uses a unique dual-axis AC motor and a stand-alone PV inverter to accomplish solar tracking. The control implementation is a technical innovation that is a simple and effective design. In addition, a scaled-down laboratory prototype is constructed to verify the feasibility of the scheme. The effectiveness of the Sun tracker is confirmed experimentally. To conclude, the results of this study may serve as valuable references for future solar energy applications.

  1. Design and Implementation of a Sun Tracker with a Dual-Axis Single Motor for an Optical Sensor-Based Photovoltaic System

    Directory of Open Access Journals (Sweden)

    Chia-Liang Lu

    2013-03-01

    Full Text Available The dual threats of energy depletion and global warming place the development of methods for harnessing renewable energy resources at the center of public interest. Solar energy is one of the most promising renewable energy resources. Sun trackers can substantially improve the electricity production of a photovoltaic (PV system. This paper proposes a novel design of a dual-axis solar tracking PV system which utilizes the feedback control theory along with a four-quadrant light dependent resistor (LDR sensor and simple electronic circuits to provide robust system performance. The proposed system uses a unique dual-axis AC motor and a stand-alone PV inverter to accomplish solar tracking. The control implementation is a technical innovation that is a simple and effective design. In addition, a scaled-down laboratory prototype is constructed to verify the feasibility of the scheme. The effectiveness of the Sun tracker is confirmed experimentally. To conclude, the results of this study may serve as valuable references for future solar energy applications.

  2. Design and Implementation of a Sun Tracker with a Dual-Axis Single Motor for an Optical Sensor-Based Photovoltaic System

    Science.gov (United States)

    Wang, Jing-Min; Lu, Chia-Liang

    2013-01-01

    The dual threats of energy depletion and global warming place the development of methods for harnessing renewable energy resources at the center of public interest. Solar energy is one of the most promising renewable energy resources. Sun trackers can substantially improve the electricity production of a photovoltaic (PV) system. This paper proposes a novel design of a dual-axis solar tracking PV system which utilizes the feedback control theory along with a four-quadrant light dependent resistor (LDR) sensor and simple electronic circuits to provide robust system performance. The proposed system uses a unique dual-axis AC motor and a stand-alone PV inverter to accomplish solar tracking. The control implementation is a technical innovation that is a simple and effective design. In addition, a scaled-down laboratory prototype is constructed to verify the feasibility of the scheme. The effectiveness of the Sun tracker is confirmed experimentally. To conclude, the results of this study may serve as valuable references for future solar energy applications. PMID:23467030

  3. An economic analysis comparison of stationary and dual-axis tracking grid-connected photovoltaic systems in the US Upper Midwest

    Science.gov (United States)

    Choi, Wongyu; Pate, Michael B.; Warren, Ryan D.; Nelson, Ron M.

    2018-05-01

    This paper presents an economic analysis of stationary and dual-axis tracking photovoltaic (PV) systems installed in the US Upper Midwest in terms of life-cycle costs, payback period, internal rate of return, and the incremental cost of solar energy. The first-year performance and energy savings were experimentally found along with documented initial cost. Future PV performance, savings, and operating and maintenance costs were estimated over 25-year assumed life. Under the given assumptions and discount rates, the life-cycle savings were found to be negative. Neither system was found to have payback periods less than the assumed system life. The lifetime average incremental costs of energy generated by the stationary and dual-axis tracking systems were estimated to be 0.31 and 0.37 per kWh generated, respectively. Economic analyses of different scenarios, each having a unique set of assumptions for costs and metering, showed a potential for economic feasibility under certain conditions when compared to alternative investments with assumed yields.

  4. Radiographic evaluations

    International Nuclear Information System (INIS)

    Williams, J.L.

    1988-01-01

    The author describes how to: perform a systematic evaluation of a chest radiograph; state the classic radiographic description of hyaline membrane disease; list the conditions that cause hyperaeration and describe the radiologic feature of hyperaeration; describe the radiograph of a patient with a congenital diaphragmatic hernia; identify optimum placement of an endotracheal tube, gastric feeding tube, and umbilical artery catheter on a radiograph; differentiate between pulmonary interstitial air and hyaline membrane disease; select radiographic features that would indicate the presence of a tension pneumothorax; describe a lateral decubitus projection and state the type of problem it is most often used to identify; explain the procedure used in obtaining a lateral neck radiograph and list two problems that may require this view; and describe the radiograph of a patient with cystic fibrosis

  5. The Nature of Scatter at the DARHT Facility and Suggestions for Improved Modeling of DARHT Facility

    Energy Technology Data Exchange (ETDEWEB)

    Morneau, Rachel Anne [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-09

    This report describes the US Stockpile Stewardship Program which is meant to sustain and evaluate nuclear weapon stockpile with no underground nuclear tests. This research will focus on DARHT, the Dual Axis Radiographic Hydrodynamic Test facility.

  6. Radiographic testing

    International Nuclear Information System (INIS)

    Kuster, J.

    1978-01-01

    In view of great differencies in X-ray transmission it is more difficult to get optimum radiographs of plastics and especially of reinforced plastics than for example of metals. A procedure will be reported how to get with little effort optimum radiographs especially also in the range of long wave-length radiation corresponding 10 to 25 kV.P. (orig.) [de

  7. Assessing delivery and quantifying efficacy of small interfering ribonucleic acid therapeutics in the skin using a dual-axis confocal microscope

    Science.gov (United States)

    Ra, Hyejun; Gonzalez-Gonzalez, Emilio; Smith, Bryan R.; Gambhir, Sanjiv S.; Kino, Gordon S.; Solgaard, Olav; Kaspar, Roger L.; Contag, Christopher H.

    2010-05-01

    Transgenic reporter mice and advances in imaging instrumentation are enabling real-time visualization of cellular mechanisms in living subjects and accelerating the development of novel therapies. Innovative confocal microscope designs are improving their utility for microscopic imaging of fluorescent reporters in living animals. We develop dual-axis confocal (DAC) microscopes for such in vivo studies and create mouse models where fluorescent proteins are expressed in the skin for the purpose of advancing skin therapeutics and transdermal delivery tools. Three-dimensional image volumes, through the different skin compartments of the epidermis and dermis, can be acquired in several seconds with the DAC microscope in living mice, and are comparable to histologic analyses of reporter protein expression patterns in skin sections. Intravital imaging with the DAC microscope further enables visualization of green fluorescent protein (GFP) reporter gene expression in the skin over time, and quantification of transdermal delivery of small interfering RNA (siRNA) and therapeutic efficacy. Visualization of transdermal delivery of nucleic acids will play an important role in the development of innovative strategies for treating skin pathologies.

  8. Radiographic positioning

    International Nuclear Information System (INIS)

    Eisenberg, R.L.; Dennis, C.A.; May, C.

    1989-01-01

    This book concentrates on the routine radiographic examinations commonly performed. It details the wide variety of examinations possible and their place in initial learning and in the radiology department as references for those occasions when an unusual examination is requested. This book provides information ranging from basic terminology to skeletal positioning to special procedures. Positions are discussed and supplemented with a picture of a patient, the resulting radiograph, and a labeled diagram. Immobilization and proper shielding of the patient are also shown

  9. Radiographic Test

    Energy Technology Data Exchange (ETDEWEB)

    Lee, H.J; Yang, S.H. [Korea Electric Power Research Institute, Taejon (Korea)

    2002-07-01

    This report contains theory, procedure technique and interpretation of radiographic examination and written for whom preparing radiographic test Level II. To determine this baseline of technical competence in the examination, the individual must demonstrate a knowledge of radiography physics, radiation safety, technique development, radiation detection and measurement, facility design, and the characteristics of radiation-producing devices and their principles of operation. (author) 98 figs., 23 tabs.

  10. Animal radiographs

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    This chapter presents historical x rays of a wide variety of animals taken within 5 years of the discovery of x radiation. Such photos were used as tests or as illustrations for radiographic publications. Numerous historical photographs are included. 10 refs

  11. Relativistic hydrodynamics

    CERN Document Server

    Luciano, Rezzolla

    2013-01-01

    Relativistic hydrodynamics is a very successful theoretical framework to describe the dynamics of matter from scales as small as those of colliding elementary particles, up to the largest scales in the universe. This book provides an up-to-date, lively, and approachable introduction to the mathematical formalism, numerical techniques, and applications of relativistic hydrodynamics. The topic is typically covered either by very formal or by very phenomenological books, but is instead presented here in a form that will be appreciated both by students and researchers in the field. The topics covered in the book are the results of work carried out over the last 40 years, which can be found in rather technical research articles with dissimilar notations and styles. The book is not just a collection of scattered information, but a well-organized description of relativistic hydrodynamics, from the basic principles of statistical kinetic theory, down to the technical aspects of numerical methods devised for the solut...

  12. Report on the behalf of the Foreign Affairs, Defence and Armed Forces Commission on the bill project authorizing the ratification of the treaty between the French Republic, the United-Kingdom of Great-Britain and Northern Ireland related to common hydrodynamic and radiographic installations

    International Nuclear Information System (INIS)

    Pintat, X.

    2011-01-01

    After a presentation of the main directions defined during the London summit for the French-British defence cooperation (convergence of interests and ambitions, cooperation in the operational, capacity, technological and industrial areas), this report more precisely presents and discusses the cooperation perspectives in the military nuclear field (deterrence by the French and British nuclear weapons, the experimentation as a field of cooperation, cooperation modalities with a common installation and a common technological development centre). These perspectives encompass experimentation installations aimed at the simulation of nuclear weapons. Then, it details the content of the treaty related to common hydrodynamic and radiographic installations: characteristics of the EPURE and TDC installations, financing conditions, and some other issues

  13. Hydrodynamic bearings

    CERN Document Server

    Bonneau, Dominique; Souchet, Dominique

    2014-01-01

    This Series provides the necessary elements to the development and validation of numerical prediction models for hydrodynamic bearings. This book describes the rheological models and the equations of lubrication. It also presents the numerical approaches used to solve the above equations by finite differences, finite volumes and finite elements methods.

  14. Hydrodynamic Lubrication

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 9. Hydrodynamic Lubrication Experiment with 'Floating' Drops. Jaywant H Arakeri K R Sreenivas. General Article Volume 1 Issue 9 September 1996 pp 51-58. Fulltext. Click here to view fulltext PDF. Permanent link:

  15. Theoretical hydrodynamics

    CERN Document Server

    Milne-Thomson, L M

    2011-01-01

    This classic exposition of the mathematical theory of fluid motion is applicable to both hydrodynamics and aerodynamics. Based on vector methods and notation with their natural consequence in two dimensions - the complex variable - it offers more than 600 exercises and nearly 400 diagrams. Prerequisites include a knowledge of elementary calculus. 1968 edition.

  16. Hydrodynamic disperser

    Energy Technology Data Exchange (ETDEWEB)

    Bulatov, A.I.; Chernov, V.S.; Prokopov, L.I.; Proselkov, Yu.M.; Tikhonov, Yu.P.

    1980-01-15

    A hydrodynamic disperser is suggested which contains a housing, slit nozzles installed on a circular base arranged opposite from each other, resonators secured opposite the nozzle and outlet sleeve. In order to improve the effectiveness of dispersion by throttling the flow, each resonator is made in the form of a crimped plate with crimpings that decrease in height in a direction towards the nozzle.

  17. Radiographic element

    International Nuclear Information System (INIS)

    Abbott, T.I.; Jones, C.G.

    1984-01-01

    Radiographic elements are disclosed comprised of first and second silver halide emulsion layers separated by an interposed support capable of transmitting radiation to which the second image portion is responsive. At least the first imaging portion contains a silver halide emulsion in which thin tubular silver halide grains of intermediate aspect ratios (from 5:1 to 8:1) are present. Spectral sensitizing dye is adsorbed to the surface of the tubular grains. Increased photographic speeds can be realized at comparable levels of crossover. (author)

  18. Radiographic apparatus

    International Nuclear Information System (INIS)

    Lapidus, S.N.

    1979-01-01

    Raytheon Company, U.S.A. have patented an on-line electronic system of normalising the responses from the photomultiplier tubes used in conjunction with a scintillator in an X-ray radiographic camera. A problem with present cameras is that the individual photomultipliers have different intensity responses which also change in time with respect to each other. The individual responses of each photomultiplier tube are measured with a uniform sheet of radioactive material in front of the camera. The associated electronic equipment then calculates scaling factors which give all photomultiplier tubes an identical response and then places these factors in an addressable store. The store is then addressed in an on-line mode to produce a visual display of the transmitted X-rays. (U.K.)

  19. Radiographic apparatus

    International Nuclear Information System (INIS)

    Dalton, B.L.

    1984-01-01

    This patent application describes a radiographic apparatus including an array of radiation sensors, a source of radiation for projecting a beam through a body and means for moving one of said source and array relative to the body and for producing an electrical signal representative of the movement of the other of said source and array needed to bring the array into register with the beam. Drive means are arranged to move the other of said source and array in response to the electrical signal. In one embodiment, the source is rotated by an amount measured by a grating and associated electronics. The required movement of the array to maintain registration is calculated and transmitted to a driver. Alternatively, a laser may be mounted with the same and the array driven so that the laser beam continuously impinges on a photocell mounted with the array. (author)

  20. Radiographers and trainee radiologists reporting accident radiographs

    DEFF Research Database (Denmark)

    Buskov, L; Abild, A; Christensen, A

    2013-01-01

    To compare the diagnostic accuracy and clinical validity of reporting radiographers with that of trainee radiologists whom they have recently joined in reporting emergency room radiographs at Bispebjerg University Hospital....

  1. Radiographic tales

    DEFF Research Database (Denmark)

    Mussmann, Bo Redder

    Purpose Until now a large number of scientific studies have focused on technological aspects of radiography. This study is a step in another direction which examines the relationship between man and technology within radiography instead of considering man and technology as separate entities. Meth...... of their narrative alertness. Errors and failure to keep the time schedule can, however, lead the radiographers to a change of perspective that makes them displace man from the scene of radiography by playing on the premises of technology.......Purpose Until now a large number of scientific studies have focused on technological aspects of radiography. This study is a step in another direction which examines the relationship between man and technology within radiography instead of considering man and technology as separate entities...... a practice in which the relationship between man and technology is marked by a struggle of domination of one over the other. The struggle expresses itself through two competing plots: A diagnostic plot with a prevailing, but not merely chronological structure mostly composed of events tied to pathology...

  2. Supernova hydrodynamics

    International Nuclear Information System (INIS)

    Colgate, S.A.

    1981-01-01

    The explosion of a star supernova occurs at the end of its evolution when the nuclear fuel in its core is almost, or completely, consumed. The star may explode due to a small residual thermonuclear detonation, type I SN or it may collapse, type I and type II SN leaving a neutron star remnant. The type I progenitor should be thought to be an old accreting white dwarf, 1.4 M/sub theta/, with a close companion star. A type II SN is thought to be a massive young star 6 to 10 M/sub theta/. The mechanism of explosion is still a challenge to our ability to model the most extreme conditions of matter and hydrodynamics that occur presently and excessively in the universe. 39 references

  3. Submarine hydrodynamics

    CERN Document Server

    Renilson, Martin

    2015-01-01

    This book adopts a practical approach and presents recent research together with applications in real submarine design and operation. Topics covered include hydrostatics, manoeuvring, resistance and propulsion of submarines. The author briefly reviews basic concepts in ship hydrodynamics and goes on to show how they are applied to submarines, including a look at the use of physical model experiments. The issues associated with manoeuvring in both the horizontal and vertical planes are explained, and readers will discover suggested criteria for stability, along with rudder and hydroplane effectiveness. The book includes a section on appendage design which includes information on sail design, different arrangements of bow planes and alternative stern configurations. Other themes explored in this book include hydro-acoustic performance, the components of resistance and the effect of hull shape. Readers will value the author’s applied experience as well as the empirical expressions that are presented for use a...

  4. Physical hydrodynamics

    CERN Document Server

    Guyon, Etienne; Petit, Luc; Mitescu, Catalin D

    2015-01-01

    This new edition is an enriched version of the textbook of fluid dynamics published more than 10 years ago. It retains the same physically oriented pedagogical perspective. This book emphasizes, as in the first edition, experimental inductive approaches and relies on the study of the mechanisms at play and on dimensional analysis rather than more formal approaches found in many classical textbooks in the field. The need for a completely new version also originated from the increase, over the last few decades, of the cross-overs between the mechanical and physical approaches, as is visible in international meetings and joint projects. Hydrodynamics is more widely linked today to other fields of experimental sciences: materials, environment, life sciences and earth sciences, as well as engineering sciences.

  5. Introduction to hydrodynamics

    International Nuclear Information System (INIS)

    Wilkins, M.L.

    1979-01-01

    Various aspects of hydrodynamics and elastic--plastic flow are introduced for the purpose of defining hydrodynamic terms and explaining what some of the important hydrodynamic concepts are. The first part covers hydrodynamic theory; and discussed fundamental hydrodynamic equations, discontinuities, and shock, detonation, and elastic--plastic waves. The second part deals with applications of hydrodynamic theory to material equations of state, spall, Taylor instabilities, and detonation pressure measurements

  6. Thermo-hydrodynamic lubrication in hydrodynamic bearings

    CERN Document Server

    Bonneau, Dominique; Souchet, Dominique

    2014-01-01

    This Series provides the necessary elements to the development and validation of numerical prediction models for hydrodynamic bearings. This book describes the thermo-hydrodynamic and the thermo-elasto-hydrodynamic lubrication. The algorithms are methodically detailed and each section is thoroughly illustrated.

  7. Hydrodynamic dispersion

    International Nuclear Information System (INIS)

    Pryce, M.H.L.

    1985-01-01

    A dominant mechanism contributing to hydrodynamic dispersion in fluid flow through rocks is variation of travel speeds within the channels carrying the fluid, whether these be interstices between grains, in granular rocks, or cracks in fractured crystalline rocks. The complex interconnections of the channels ensure a mixing of those parts of the fluid which travel more slowly and those which travel faster. On a macroscopic scale this can be treated statistically in terms of the distribution of times taken by a particle of fluid to move from one surface of constant hydraulic potential to another, lower, potential. The distributions in the individual channels are such that very long travel times make a very important contribution. Indeed, while the mean travel time is related to distance by a well-defined transport speed, the mean square is effectively infinite. This results in an asymmetrical plume which differs markedly from a gaussian shape. The distribution of microscopic travel times is related to the distribution of apertures in the interstices, or in the microcracks, which in turn are affected in a complex way by the stresses acting on the rock matrix

  8. Chromatin Hydrodynamics

    Science.gov (United States)

    Bruinsma, Robijn; Grosberg, Alexander Y.; Rabin, Yitzhak; Zidovska, Alexandra

    2014-01-01

    Following recent observations of large scale correlated motion of chromatin inside the nuclei of live differentiated cells, we present a hydrodynamic theory—the two-fluid model—in which the content of a nucleus is described as a chromatin solution with the nucleoplasm playing the role of the solvent and the chromatin fiber that of a solute. This system is subject to both passive thermal fluctuations and active scalar and vector events that are associated with free energy consumption, such as ATP hydrolysis. Scalar events drive the longitudinal viscoelastic modes (where the chromatin fiber moves relative to the solvent) while vector events generate the transverse modes (where the chromatin fiber moves together with the solvent). Using linear response methods, we derive explicit expressions for the response functions that connect the chromatin density and velocity correlation functions to the corresponding correlation functions of the active sources and the complex viscoelastic moduli of the chromatin solution. We then derive general expressions for the flow spectral density of the chromatin velocity field. We use the theory to analyze experimental results recently obtained by one of the present authors and her co-workers. We find that the time dependence of the experimental data for both native and ATP-depleted chromatin can be well-fitted using a simple model—the Maxwell fluid—for the complex modulus, although there is some discrepancy in terms of the wavevector dependence. Thermal fluctuations of ATP-depleted cells are predominantly longitudinal. ATP-active cells exhibit intense transverse long wavelength velocity fluctuations driven by force dipoles. Fluctuations with wavenumbers larger than a few inverse microns are dominated by concentration fluctuations with the same spectrum as thermal fluctuations but with increased intensity. PMID:24806919

  9. Radiographic imaging. 4 ed.

    International Nuclear Information System (INIS)

    Chesney, D.N.; Chesney, M.O.

    1981-01-01

    This is a revised edition of the textbook previously entitled 'Radiographic Photography' and accords with the current syllabus of training for the Diploma of the Royal College of Radiographers. The aim is a non-mathematical approach to provide a guide for the student to the knowledge and understanding of the theoretical concepts which affect the quality of radiographic image; materials and practices are also reviewed, particularly in relation to the characteristics of the radiographic image, and to processing equipment and processing areas. The subject is dealt with under the following headings: the photographic process, film materials in x-ray departments, sensitometry, storage of film materials and radiographs, intensifying screens and cassettes, film processing, developing, fixing, rinsing, washing, drying, the processing area and equipment, systems for daylight film handling, the radiographic image, management of the quality, presentation of the radiograph, light images and their recording, fluorography, some special imaging processes, e.g. xerography, copying radiographs. (U.K.)

  10. Quality of radiograph

    International Nuclear Information System (INIS)

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

    2008-01-01

    This chapter discussed on how to get a good radiograph. There are several factors that can make good radiograph such as density of radiograph, the contrast of radiograph, definition of radiograph, the present of artifact and backscattering. All of this factor will discuss detailed on each unit of chapter with some figure, picture to make the reader understand more when read this book. And at the end, the reader will introduce with penetrameter, one of device to determine the level of quality of the radiograph. There are two type of penetrameter like wire type or holes type. This standard must be followed by all the radiographer around the world to produce the good result that is standard and more reliable.

  11. Fast radiographic systems

    International Nuclear Information System (INIS)

    Domanus, J.C.

    1984-08-01

    Industrial radiography can be performed with shorter exposure times, when instead of X-ray film with lead intensifying screens the radiographic paper with fluorescent screen is used. With paper radiography one can obtain lower material, equipment, and labor costs, shorter exposure and processing times, and easier radiation protection. The speed of the radiographic inspection can also be increased by the use of fluorometallic intensifying screens together with a special brand of X-ray film. Before accepting either of the two fast radiographic systems one must be sure that they can produce radiographs of adequate image quality. Therefore an investigation was performed on that subject using ISO wire IQI's and ASTM penetrameters. The radiographic image quality was tested for aluminium and steel up to 30 mm thick using various brands of radiographic paper and X-ray film with fluorometallic screens and comparing them with fast X-ray films with lead screens. Both systems give satisfactory results. (author)

  12. Radiographic constant exposure technique

    DEFF Research Database (Denmark)

    Domanus, Joseph Czeslaw

    1985-01-01

    The constant exposure technique has been applied to assess various industrial radiographic systems. Different X-ray films and radiographic papers of two producers were compared. Special attention was given to fast film and paper used with fluorometallic screens. Radiographic image quality...... was tested by the use of ISO wire IQI's and ASTM penetrameters used on Al and Fe test plates. Relative speed and reduction of kilovoltage obtained with the constant exposure technique were calculated. The advantages of fast radiographic systems are pointed out...

  13. Visual simulation of radiographs

    International Nuclear Information System (INIS)

    Laguna, G.

    1985-01-01

    A method for computer simulation of radiographs has been added to the LLNL version of the solid modeler TIPS-1 (Technical Information Processing System-1). This new tool will enable an engineer to compare an actual radiograph of a solid to its computer-generated counterpart. The appearance of discrepancies between the two can be an indication of flaws in the solid object. Simulated radiographs can also be used to preview the placement of x-ray sources to focus on areas of concern before actual radiographs are made

  14. Legalities of the radiograph

    International Nuclear Information System (INIS)

    Bundy, A.L.

    1988-01-01

    The radiograph itself plays a major role in medical malpractice cases. Also, many questions arise concerning the rights to and storage of x-ray films. These issues are addressed in this chapter. To keep the terminology simple, the word radiograph represents all imaging documentation on hard copy film (x-rays, nuclear medicine, computer-assisted studies, ultrasound, and magnetic resonance imaging)

  15. Elasto-hydrodynamic lubrication

    CERN Document Server

    Dowson, D; Hopkins, D W

    1977-01-01

    Elasto-Hydrodynamic Lubrication deals with the mechanism of elasto-hydrodynamic lubrication, that is, the lubrication regime in operation over the small areas where machine components are in nominal point or line contact. The lubrication of rigid contacts is discussed, along with the effects of high pressure on the lubricant and bounding solids. The governing equations for the solution of elasto-hydrodynamic problems are presented.Comprised of 13 chapters, this volume begins with an overview of elasto-hydrodynamic lubrication and representation of contacts by cylinders, followed by a discussio

  16. Elementary classical hydrodynamics

    CERN Document Server

    Chirgwin, B H; Langford, W J; Maxwell, E A; Plumpton, C

    1967-01-01

    Elementary Classical Hydrodynamics deals with the fundamental principles of elementary classical hydrodynamics, with emphasis on the mechanics of inviscid fluids. Topics covered by this book include direct use of the equations of hydrodynamics, potential flows, two-dimensional fluid motion, waves in liquids, and compressible flows. Some general theorems such as Bernoulli's equation are also considered. This book is comprised of six chapters and begins by introducing the reader to the fundamental principles of fluid hydrodynamics, with emphasis on ways of studying the motion of a fluid. Basic c

  17. Producing quality radiographic images

    International Nuclear Information System (INIS)

    Cullinan, A.M.

    1987-01-01

    This book gives an overview of physics, equipment, imaging, and quality assurance in the radiology department. The chapters are laid out with generous use of subheads to allow for quick reference, Points are illustrated with clear, uncluttered line diagrams and well-produced images. The accompanying explanations are miniature lessons by themselves. Inserted at various points throughout the text are important notes that highlight key concepts. The chapter ''Image Evaluation and Application of Radiographic Principles'' present a systematic approach to evaluating radiographs and contains several sample radiographs to illustrate the points made

  18. Rapidly processable radiographic material

    International Nuclear Information System (INIS)

    Brabandere, L.A. de; Borginon, H.A.; Pattyn, H.A.; Pollet, R.J.

    1981-01-01

    A new rapidly processable radiographic silver halide material is described for use in mammography and non-destructive testing of industrial materials. The radiographic material is used for direct exposure to penetrating radiation without the use of fluorescent-intensifying screens. It consists of a transparent support with a layer of hydrophilic colloid silver halide emulsion on one or both sides. Examples of the preparation of three different silver halide emulsions are given including the use of different chemical sensitizers. These new radiographic materials have good resistance to the formation of pressure marks in rapid processing apparatus and they have improved sensitivity for direct exposure to penetrating radiation compared to conventional radiographic emulsions. (U.K.)

  19. Radiographic manifestations of hypochondroplasia

    Energy Technology Data Exchange (ETDEWEB)

    Heselson, N G; Cremin, B J [Groote Schuur Hospital, Cape Town (South Africa); Beighton, P

    1979-01-01

    Hypochrondroplasia is an inherited skeletal dysplasia that resembles achondroplasia in mild degree. Radiographic manifestations encountered in 12 affected individuals in South Africa include slight shortening of all segments of the tubular bones, moderate caudal diminution of the lumbar interpedicular distances, increased lumbar lordosis with cacral tilt and distal prolongation of the fibular. Hypochondroplasia can be distinguished from other osteochondrodystrophies such as achondroplasia, pseudo-achondroplasia and metaphyseal chondroplasia by the recognition of it clinical and radiographic manifestations.

  20. Radiographic examination of the equine foot

    International Nuclear Information System (INIS)

    Park, R.D.

    1989-01-01

    A complete radiographic examination of the equine foot consists of properly exposed, processed, and positioned radiographs. For radiographic interpretation, in addition to knowing radiographic signs of disease, a knowledge of normal radiographic anatomy and possible insignificant anatomic variations is necessary

  1. Radiographic aspects of xeroradiography

    International Nuclear Information System (INIS)

    Rao, G.U.V.; Fatouros, P.P.

    1980-01-01

    The quality of a conventional radiographic image can be characterized in terms of five basic parameters; density, contrast, latitude, resolution and noise. Since xeroradiographic images exhibit very limited broad area contrasts, and image formation is predominantly due to edge enhancement, a straightforward description of image quality using the same five parameters is not adequate. A detailed study was made of the radiographic aspects of xeroradiography with special reference to mammography, and a summary of major findings to date with appropriate references to published papers is presented

  2. Nondestructive examination - radiographic techniques

    International Nuclear Information System (INIS)

    Maier, H.J.

    1980-01-01

    First the basic principles of radiography are to be treated, especially the different radiation sources (X-ray, gamma-ray, neutrons, heat). In the second part those radiographic methods are shown, which are in common use for technical purposes, especially under the aspect of flaw recognition. (orig./RW)

  3. Matching hand radiographs

    NARCIS (Netherlands)

    Kauffman, J.A.; Slump, Cornelis H.; Bernelot Moens, H.J.

    2005-01-01

    Biometric verification and identification methods of medical images can be used to find possible inconsistencies in patient records. Such methods may also be useful for forensic research. In this work we present a method for identifying patients by their hand radiographs. We use active appearance

  4. Stabilized radiographic scanning agent

    International Nuclear Information System (INIS)

    Fawzi, M.B.

    1979-01-01

    A stable composition useful in preparation of technetium-99m-based radiographic scanning agents has been developed. The composition contains a stabilizing amount of gentisate stabilizer selected from gentisic acid and its soluble pharmaceutically-acceptable salts and esthers. (E.G.)

  5. Radiographic scanning agent

    International Nuclear Information System (INIS)

    Tofe, A.J.

    1976-01-01

    A stable radiographic scanning agent on a sup(99m)Tc basis has been developed. The substance contains a pertechnetate reduction agent, tin(II)-chloride, chromium(II)-chloride, or iron(II)-sulphate, as well as an organospecific carrier and ascorbic acid or a pharmacologically admissible salt or ester of ascorbic acid. (VJ) [de

  6. Computed tomography for radiographers

    International Nuclear Information System (INIS)

    Brooker, M.J.

    1986-01-01

    This book is directed towards giving radiographers an introduction to and basic knowledge of computerized tomography. The technical section discusses gantries and x-ray production, computer and disc drive image display, storage, artefacts quality assurance and design of departments. The clinical section includes patient preparation, radiotherapy planning, and interpretation of images from various areas of the anatomy. (U.K.)

  7. Hydrodynamic optical soliton tunneling

    Science.gov (United States)

    Sprenger, P.; Hoefer, M. A.; El, G. A.

    2018-03-01

    A notion of hydrodynamic optical soliton tunneling is introduced in which a dark soliton is incident upon an evolving, broad potential barrier that arises from an appropriate variation of the input signal. The barriers considered include smooth rarefaction waves and highly oscillatory dispersive shock waves. Both the soliton and the barrier satisfy the same one-dimensional defocusing nonlinear Schrödinger (NLS) equation, which admits a convenient dispersive hydrodynamic interpretation. Under the scale separation assumption of nonlinear wave (Whitham) modulation theory, the highly nontrivial nonlinear interaction between the soliton and the evolving hydrodynamic barrier is described in terms of self-similar, simple wave solutions to an asymptotic reduction of the Whitham-NLS partial differential equations. One of the Riemann invariants of the reduced modulation system determines the characteristics of a soliton interacting with a mean flow that results in soliton tunneling or trapping. Another Riemann invariant yields the tunneled soliton's phase shift due to hydrodynamic interaction. Soliton interaction with hydrodynamic barriers gives rise to effects that include reversal of the soliton propagation direction and spontaneous soliton cavitation, which further suggest possible methods of dark soliton control in optical fibers.

  8. Hydrodynamic Expansion of Pellicles Caused by e-Beam Heating

    CERN Document Server

    Ho, D

    2000-01-01

    Placing a pellicle in front of a x-ray converter target for radiographic applications can confine the backstreaming ions and target plasma to a shorter channel so that the cumulative effect on e-beam focusing is reduced. The pellicle is subject to heating by e-beam since the pellicle is placed upstream of the target. The calculation of the hydrodynamic expansion, caused by the heating, using the radiation hydrodynamics code LASNEX is presented in this report. Calculations show that mylar pellicles disintegrate at the end of a multi-pulse intense e-beam while beryllium and carbon pellicles remain intact. The expansions for the kapton-carbon multi-layered targets are also examined. Hydrodynamic expansions for pellicles with various e-beam spot radii are calculated for DARHT-II beam parameters. All the simulation results indicate that the backstreaming ions can be stopped.

  9. Radiographic progession of rheumatoid arthritis

    International Nuclear Information System (INIS)

    Siozos, C.D.

    1981-01-01

    The radiographic progression of rheumatoid arthritis can be graded on a 0-IV scala. For this purpose five objective criteria are used: a) destruction, b) osteoporosis, c) narrowing of joint space, d) luxation and e) ankylosis. The grading of the radiographic progression is defined by the extent and the number of the measured alterations. The radiographic progression can be registered yearly. (orig.) [de

  10. Small systems – hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Bożek, Piotr, E-mail: piotr.bozek@fis.agh.edu.pl

    2016-12-15

    The scenario assuming a collective expansion stage in collisions of small systems, p-A, d-Au, and {sup 3}He-Au is discussed. A review of the observables predicted in relativistic hydrodynamic models in comparison with experimental data is presented, with arguments indicating the presence of collective expansion. The limits of applicability of the hydrodynamic model are addressed. We briefly indicate possible applications of the collective flow in small systems to study the space-time dynamics at very small scales in relativistic collisions.

  11. Modeling dental radiographic systems

    International Nuclear Information System (INIS)

    Webber, R.L.

    1980-01-01

    The Bureau of Radiological Health has been actively collaborating with the Clinical Investigations Branch, NIDR, in applied research involving diagnostic use of ionizing radiation in dentistry. This work has centered on the search for alternatives to conventional radiographic systems in an attempt to improve diagnostic performance while reducing the required exposure. The basic approach involves analysis of factors limiting performance of properly defined diagnostic tasks and the modeling alternative systems with an eye toward increasing objective measures of performance. Previous collaborative work involved using a nonlinear model to compare various x-ray spectra. The data were expressed as brightness-contrast versus exposure for simulated tasks of clinical interest. This report supplements these findings by extending the number of parameters under investigation and modifying the mode of data display so that an actual radiographic image can be simulated on a television screen

  12. Pocket atlas of radiographic anatomy

    International Nuclear Information System (INIS)

    Moeller, T.B.; Reif, E.; Stark, P.

    1993-01-01

    The 'Pocket Atlas of Radiographic Anatomy' presents 170 radiographs of the various body regions of adults, showing only the normal radiographic anatomy. Each radiograph is supplemented on the opposite page by a drawing of the particular body region. There is no commenting text, but the drawings are provided with captions in English. The atlas is a useful guide for interpreting radiographs. The pictures are arranged in chapters entitled as follows: Skeletal Imaging (skull, spine, upper extremity), lower extremity; Miscellaneous Plain Films (chest, mammogram, trachea, lung tomograms); Contrast Examinations (gastrointestinal tract, intravenous contrast examinations, arthrography, angiography); Special Examinations (myelograms, lymphangiograms, bronchograms, sialograms). (UWA). 348 figs [de

  13. Hydrodynamical description of collective flow

    OpenAIRE

    Huovinen, Pasi

    2003-01-01

    I review how hydrodynamical flow is related to the observed flow in ultrarelativistic heavy ion collisions and how initial conditions, equation of state and freeze-out temperature affect flow in hydrodynamical models.

  14. Report on the behalf of the Foreign Affairs, Defence and Armed Forces Commission on the bill project authorizing the ratification of the treaty between the French Republic, the United-Kingdom of Great-Britain and Northern Ireland related to common hydrodynamic and radiographic installations; Rapport fait au nom de la commission des affaires etrangeres, de la defense et des forces armees (1) sur le projet de loi autorisant la ratification du traite entre la Republique francaise et le Royaume-Uni de Grande Bretagne et d'Irlande du nord relatif a des installations radiographiques et hydrodynamiques communes

    Energy Technology Data Exchange (ETDEWEB)

    Pintat, X.

    2011-07-01

    After a presentation of the main directions defined during the London summit for the French-British defence cooperation (convergence of interests and ambitions, cooperation in the operational, capacity, technological and industrial areas), this report more precisely presents and discusses the cooperation perspectives in the military nuclear field (deterrence by the French and British nuclear weapons, the experimentation as a field of cooperation, cooperation modalities with a common installation and a common technological development centre). These perspectives encompass experimentation installations aimed at the simulation of nuclear weapons. Then, it details the content of the treaty related to common hydrodynamic and radiographic installations: characteristics of the EPURE and TDC installations, financing conditions, and some other issues

  15. Dissipative relativistic hydrodynamics

    International Nuclear Information System (INIS)

    Imshennik, V.S.; Morozov, Yu.I.

    1989-01-01

    Using the comoving reference frame in the general non-inertial case, the relativistic hydrodynamics equations are derived with an account for dissipative effects in the matter. From the entropy production equation, the exact from for the dissipative tensor components is obtained. As a result, the closed system of equations of dissipative relativistic hydrodynamics is obtained in the comoving reference frame as a relativistic generalization of the known Navier-Stokes equations for Lagrange coordinates. Equations of relativistic hydrodynamics with account for dissipative effects in the matter are derived using the assocoated reference system in general non-inertial case. True form of the dissipative tensor components is obtained from entropy production equation. Closed system of equations for dissipative relativistic hydrodynamics is obtained as a result in the assocoated reference system (ARS) - relativistic generalization of well-known Navier-Stokes equations for Lagrange coordinates. Equation system, obtained in this paper for ARS, may be effectively used in numerical models of explosive processes with 10 51 erg energy releases which are characteristic for flashes of supernovae, if white dwarf type compact target suggested as presupernova

  16. Radiographic findings in immunodeficiency

    International Nuclear Information System (INIS)

    Obregon, R.; Lynch, D.A.; Cink, T.M.; Newell, J.D.; Kirkpatrick, C.

    1991-01-01

    This paper reviews the chest radiographs and high-resolution CT (HRCT) scans in patients with immunodeficiency disorders and define the role of HRCT. Thirty-three cases were retrospectively graded according to the consensus of two radiologists. Patients with HIV seropositivity and asthma were excluded. HRCT was performed in 12 cases with standard techniques. Diagnoses included common variable hypogammaglobulinemia (n = 19), X-linked agammaglobulinemia (n = 4), chronic mucocutaneous candidiasis (n = 4), and selective immunoglobulin g deficiencies (n = 2). Chest radiographs showed bronchiectasis in 11 of 33 cases with a predominant lower lobe distribution (82%). Nodules were present in six cases and mucus plugs in four cases. HRCT showed bronchiectasis in nine of 12 cases; in five of these nine cases, bronchiectasis was not apparent on chest radiographs. Other HRCT findings included segmental air trapping (four of 12), mucus plugs (three of 12), hazy consolidation (four of 12), nodules (five of 12), and bronchiolectasis (two of 12). Therapy was altered in seven of 12 cases in which HRCT was performed. Most pertinent to clinical management were the presence of a thymoma (n = 1) and severe focal of diffuse bronchiectasis

  17. Large Format Radiographic Imaging

    International Nuclear Information System (INIS)

    Rohrer, J. S.; Stewart, Lacey; Wilke, M. D.; King, N. S.; Baker A, S.; Lewis, Wilfred

    1999-01-01

    Radiographic imaging continues to be a key diagnostic in many areas at Los Alamos National Laboratory (LANL). Radiographic recording systems have taken on many form, from high repetition-rate, gated systems to film recording and storage phosphors. Some systems are designed for synchronization to an accelerator while others may be single shot or may record a frame sequence in a dynamic radiography experiment. While film recording remains a reliable standby in the radiographic community, there is growing interest in investigating electronic recording for many applications. The advantages of real time access to remote data acquisition are highly attractive. Cooled CCD camera systems are capable of providing greater sensitivity with improved signal-to-noise ratio. This paper begins with a review of performance characteristics of the Bechtel Nevada large format imaging system, a gated system capable of viewing scintillators up to 300 mm in diameter. We then examine configuration alternatives in lens coupled and fiber optically coupled electro-optical recording systems. Areas of investigation include tradeoffs between fiber optic and lens coupling, methods of image magnification, and spectral matching from scintillator to CCD camera. Key performance features discussed include field of view, resolution, sensitivity, dynamic range, and system noise characteristics

  18. Radiographic testing of wood

    International Nuclear Information System (INIS)

    Osterloh, K.; Zscherpel, U.; Raedel, C.; Weidemann, G.; Meinel, D.; Goebbels, J.; Ewert, U.; Hasenstab, A.; Buecherl, T.

    2007-01-01

    Wood is an old and established consumption and construction material. It is still the most common material for constructing furniture, roofs, playgrounds and mine supports. In contrast to steel and concrete, wood warns of extreme loads by creaking. Its mechanical stability is more influenced by decay than by peripheral cracks. While external cracks are visible, internal decay by fungus growth is undetectable from outside. This may be a safety problem in supporting structures. The best analysis of the internal structure is provided by computed tomography, but this is also the most complex method, much more so than simple radiographic testing. However, the latter is made inaccurate by scattered radiation resulting from internal moisture. With the image processing options of digital radiographic techniques, the structural information can be separated effectively from noise. In contrast to X-ray and gamma radiography, neutron radiography provides information on the spatial distribution of moisture. In healthy wood, water is conducted in the sapwood while the hardwood is dry. Moisture in hardwood is caused by infestations, e.g. fungus growth. The contribution presents a comparative analysis of the available radiographic methods. (orig.)

  19. Radiograph identifying means

    International Nuclear Information System (INIS)

    Sheldon, A.D.

    1983-01-01

    A flexible character-indentable plastics embossing tape is backed by and bonded to a lead strip, not more than 0.025 inches thick, to form a tape suitable for identifying radiographs. The lead strip is itself backed by a relatively thin and flimsy plastics or fabric strip which, when removed, allows the lead plastic tape to be pressure-bonded to the surface to be radiographed. A conventional tape-embossing gun is used to indent the desired characters in succession into the lead-backed tape, without necessarily severing the lead; and then the backing strip is peeled away to expose the layer of adhesive which pressure-bonds the indented tape to the object to be radiographed. X-rays incident on the embossed tape will cause the raised characters to show up dark on the subsequently-developed film, whilst the raised side areas will show up white. Each character will thus stand out on the developed film. (author)

  20. Radiographic evaluation of osteosynthesis

    International Nuclear Information System (INIS)

    Mueller-Miny, H.; Erlemann, R.; Roos, N.; Peters, P.E.; Baranowski, D.

    1991-01-01

    Surgeons, orthopedic surgeons, and neurosurgeons employ a wide variety of different osteosynthetic devices in the treatment of fractures and in spinal surgery. In order to assess these instruments correctly, the radiologist should be aware of their purpose and normal apperance. The complications should be identified, such as delayed union, pseudarthrosis, dislocation, device loosening, fracture of the device, osteomyelitis, and refracture. To evaluate the fixation device adequately two plain radiographs are mandatory. An normal fracture healing and the most commonly used fixation devices, the abnormalities of fracture healing and their complications are discussed. (orig.) [de

  1. Digitization of conventional radiographs

    International Nuclear Information System (INIS)

    Wenz, W.; Buitrago-Tellez, C.; Blum, U.; Hauenstein, K.H.; Gufler, H.; Meyer, E.; Ruediger, K.

    1992-01-01

    The diagnostic value of a digitization system for analogue films based on a charge-coupled-device (CCD) scanner with adjustable resolution of 2.5 or 5 lp/mm was assessed. Some 110 skeletal radiographs, 50 contrast studies, including 25 of patients with Crohn's disease, and 70 abdominal plain films before and after successful lithotripsy for renal stones were digitized. Receiver operating characteristic (ROC) studies showed improved detection of cortical and trabecular defects with contrast-optimized digitized films. Edge enhancement algorithms yielded no additional information. Inflammatory lesions of Crohn's disease were detected equally well by conventional films and digitized images. A statistically significant improvement (p [de

  2. Radiographic scanning agent

    International Nuclear Information System (INIS)

    Bevan, J.A.

    1983-01-01

    This invention relates to radiodiagnostic agents and more particularly to a composition and method for preparing a highly effective technetium-99m-based bone scanning agent. One deficiency of x-ray examination is the inability of that technique to detect skeletal metastases in their incipient stages. It has been discovered that the methanehydroxydiphosphonate bone mineral-seeking agent is unique in that it provides the dual benefits of sharp radiographic imaging and excellent lesion detection when used with technetium-99m. This agent can also be used with technetium-99m for detecting soft tissue calcification in the manner of the inorganic phosphate radiodiagnostic agents

  3. Radiographic film digitizing devices

    International Nuclear Information System (INIS)

    McFee, W.H.

    1988-01-01

    Until recently, all film digitizing devices for use with teleradiology or picture archiving and communication systems used a video camera to capture an image of the radiograph for subsequent digitization. The development of film digitizers that use a laser beam to scan the film represents a significant advancement in digital technology, resulting in improved image quality compared with video scanners. This paper discusses differences in resolution, efficiency, reliability, and the cost between these two types of devices. The results of a modified receiver operating characteristic comparison study of a video scanner and a laser scanner manufactured by the same company are also discussed

  4. Hydrodynamics of Turning Flocks

    OpenAIRE

    Yang, Xingbo; Marchetti, M. Cristina

    2014-01-01

    We present a hydrodynamic model of flocking that generalizes the familiar Toner-Tu equations to incorporate turning inertia of well-polarized flocks. The continuum equations controlled by only two dimensionless parameters, orientational inertia and alignment strength, are derived by coarse graining the inertial spin model recently proposed by Cavagna et al. The interplay between orientational inertia and bend elasticity of the flock yields anisotropic spin waves that mediate the propagation o...

  5. Hydrodynamics of insect spermatozoa

    Science.gov (United States)

    Pak, On Shun; Lauga, Eric

    2010-11-01

    Microorganism motility plays important roles in many biological processes including reproduction. Many microorganisms propel themselves by propagating traveling waves along their flagella. Depending on the species, propagation of planar waves (e.g. Ceratium) and helical waves (e.g. Trichomonas) were observed in eukaryotic flagellar motion, and hydrodynamic models for both were proposed in the past. However, the motility of insect spermatozoa remains largely unexplored. An interesting morphological feature of such cells, first observed in Tenebrio molitor and Bacillus rossius, is the double helical deformation pattern along the flagella, which is characterized by the presence of two superimposed helical flagellar waves (one with a large amplitude and low frequency, and the other with a small amplitude and high frequency). Here we present the first hydrodynamic investigation of the locomotion of insect spermatozoa. The swimming kinematics, trajectories and hydrodynamic efficiency of the swimmer are computed based on the prescribed double helical deformation pattern. We then compare our theoretical predictions with experimental measurements, and explore the dependence of the swimming performance on the geometric and dynamical parameters.

  6. Interpreting radiographs. 4. The carpus

    International Nuclear Information System (INIS)

    Burguez, P.N.

    1984-01-01

    The complexity of the carpus which has three major joints, seven or eight carpal bones and five adjacent bones, each of which articulates with one or more of the carpal elements, necessitates good quality radiographs for definitive radiographic interpretation may be extremely difficult because of the disparity between radiographic changes and obvious clinical signs and, therefore, must be discussed in the light of a thorough clinical assessment

  7. Radiographer interpretation of trauma radiographs: Issues for radiography education providers

    International Nuclear Information System (INIS)

    Hardy, Maryann; Snaith, Beverly

    2009-01-01

    Background: The role of radiographers with respect to image interpretation within clinical practice is well recognised. It is the expectation of the professional, regulatory and academic bodies that upon qualification, radiographers will possess image interpretation skills. Additionally, The College of Radiographers has asserted that its aspiration is for all radiographers to be able to provide an immediate written interpretation on skeletal trauma radiographs by 2010. This paper explores the readiness of radiography education programmes in the UK to deliver this expectation. Method: A postal questionnaire was distributed to 25 Higher Education Institutions in the UK (including Northern Ireland) that provided pre-registration radiography education as identified from the Society and College of Radiographers register. Information was sought relating to the type of image interpretation education delivered at pre- and post-registration levels; the anatomical range of image interpretation education; and education delivery styles. Results: A total of 19 responses (n = 19/25; 76.0%) were received. Image interpretation education was included as part of all radiographer pre-registration programmes and offered at post-registration level at 12 academic centres (n = 12/19; 63.2%). The anatomical areas and educational delivery methods varied across institutions. Conclusion: Radiography education providers have embraced the need for image interpretation education within both pre- and post-registration radiography programmes. As a result, UK education programmes are able to meet the 2010 College of Radiographers aspiration.

  8. Titan's hydrodynamically escaping atmosphere

    Science.gov (United States)

    Strobel, Darrell F.

    2008-02-01

    The upper atmosphere of Titan is currently losing mass at a rate ˜(4-5)×10 amus, by hydrodynamic escape as a high density, slow outward expansion driven principally by solar UV heating by CH 4 absorption. The hydrodynamic mass loss is essentially CH 4 and H 2 escape. Their combined escape rates are restricted by power limitations from attaining their limiting rates (and limiting fluxes). Hence they must exhibit gravitational diffusive separation in the upper atmosphere with increasing mixing ratios to eventually become major constituents in the exosphere. A theoretical model with solar EUV heating by N 2 absorption balanced by HCN rotational line cooling in the upper thermosphere yields densities and temperatures consistent with the Huygens Atmospheric Science Investigation (HASI) data [Fulchignoni, M., and 42 colleagues, 2005. Nature 438, 785-791], with a peak temperature of ˜185-190 K between 3500-3550 km. This model implies hydrodynamic escape rates of ˜2×10 CHs and 5×10 Hs, or some other combination with a higher H 2 escape flux, much closer to its limiting value, at the expense of a slightly lower CH 4 escape rate. Nonthermal escape processes are not required to account for the loss rates of CH 4 and H 2, inferred by the Cassini Ion Neutral Mass Spectrometer (INMS) measurements [Yelle, R.V., Borggren, N., de la Haye, V., Kasprzak, W.T., Niemann, H.B., Müller-Wodarg, I., Waite Jr., J.H., 2006. Icarus 182, 567-576].

  9. Radiographically detectable intracortical porosity

    International Nuclear Information System (INIS)

    Meema, H.E.

    1986-01-01

    Since the measurement of intracortical resorptive spaces by histologic methods is difficult and very few data are available in normal humans, we have measured their lengths and widths and calculated the intracortical porosity in metacarpals and phalanges of 79 normal women and 69 normal men, using fine-detail radiographs of the hands and a computerized semi-automatic image analysis system (Zeiss MOP-3), this being the first study of this kind. Several methodological problems were solved satisfactorily, and the results of this study could serve as a data bank for further investigations concerned with intracortical resorption. Significant differences were found between age and sex versus several intracortical resorptive parameters; also significant correlations were found with age in some cases. Normal intracortical porosity was found to be about three times greater in the proximal phalanges than in the metacarpals. It is concluded that this methodology could be used for further studies of intracortical resorption in osteoporosis and other metabolic bone diseases. (orig.)

  10. Odontogenic keratocyst radiographic features

    International Nuclear Information System (INIS)

    Nartey, N. O.; Saini, T.

    1990-01-01

    The clinical features often patients with odontogenic keratocysts were studied. One patient had Gorlin-GoJtz syndrome. A total of fourteen radiolucent lesions were observed on radiographic examination. All the fourteen lesions were diagnosed as odontogenic keratocyst after histopathclogical examination of biopsied tissue from the patients. The age at diagnosis ranged from 25-72 years with a mean age of 37.6 years. The male : female ratio was 2.3:1. Thirteen of these lesions occurred in the mandible, nine involved the mandibular third molar region. Involvement of the ramus of the mandible produced a sausage-shaped radiolucency. Cystic lesions which have been present for long periods of time showed scalloped margins, due to the regional resorption of the surrounding bone. The bony ledges present on the cortical bones simulated multilocular appearance in such cases. It was also observed that the lesions in older individuals perforated the cortical plates rather than eliciting a periostally induced bony expansion. (author)

  11. A radiographic examination system

    International Nuclear Information System (INIS)

    Cable, A.P.; Cable, W.S.

    1983-01-01

    A system for performing radiographic examination, particularly of large items such as international container units is disclosed. The system is formed as an installation comprising housings for respective linear accelerators transmitting a beam of radiation across the path of a conveyor along which the units can be displaced continuously or incrementally. On either end of the installation are container handling areas including roller conveyors with drag chains and transverse manipulators, and the whole installation is secured within automatically operated doors which seal the high energy region when a container on the conveyor is being subjected to examination. The radiation transmitted through a container is detected in a detector system incorporating a fluoroscopic screen light output from which is detected in a camera system such as a television camera, and transmitted as coded pulsed signals by a coding transfer unit to display screens where an image of the transmitted information can be displayed and/or recorded for further use. (author)

  12. Radiographic contrast media

    International Nuclear Information System (INIS)

    Golman, K.; Holtz, E.; Almen, T.

    1987-01-01

    Contrast media are used in diagnostic radiology to enhance the X-ray attenuation between a body structure of interest and the surrounding tissue. A detail becomes perceptible on a roentgenogram only when its contrast exceeds a minimum value in relation to the background. Small areas of interest must have higher contrast than the background. The contrast effect depends on concentration of the contrast media with the body. A high contrast media concentration difference thus gives rise to more morphological details in the radiographs. Contrast media can be divided into negative contrast media such as air and gas which attenuate X-rays less than the body tissues, and positive contrast materials which attenuate X-rays more than the body tissues. The positive contrast media all contain either iodine (atomic number 53) or barium (atomic number 56) and can be divided into water-insoluble and water-soluble contrast media

  13. How to fake hydrodynamic signals

    Energy Technology Data Exchange (ETDEWEB)

    Romatschke, Paul [Department of Physics, 390 UCB, University of Colorado at Boulder, Boulder, CO (United States); Center for Theory of Quantum Matter, University of Colorado, Boulder, CO 80309 (United States)

    2016-12-15

    Flow signatures in experimental data from relativistic ion collisions, are usually interpreted as a fingerprint of the presence of a hydrodynamic phase during the evolution of these systems. I review some theoretical ideas to ‘fake’ this hydrodynamic behavior in p+A and A+A collisions. I find that transverse flow and femtoscopic measurements can easily be forged through non-hydrodynamic evolution, while large elliptic flow requires some non-vanishing interactions in the hot phase.

  14. Modeling hydrodynamic cavitation

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, P.S.; Pandit, A.B. [Mumbai Univ. (India). Chemical Engineering Div.

    1999-12-01

    Cavitation as a source and method of energy input for chemical processing is increasingly studied due to its ability to generate localized high temperatures and pressures under nearly ambient conditions. Compared to cavitation generated by ultrasound, hydrodynamic cavitation has been proved to be a very energy-efficient alternative. A simple and unified model has been developed to study the cavitation phenomena in hydraulic systems with emphasis on the venturi tube and high-speed homogenizer. The model has been found to be satisfactory in explaining the effect of operating variables and equipment geometry on two different modes of cavitation generation qualitatively and in some cases quantitatively. (orig.)

  15. Hydrodynamics of Ship Propellers

    DEFF Research Database (Denmark)

    Breslin, John P.; Andersen, Poul

    This book deals with flows over propellers operating behind ships, and the hydrodynamic forces and moments which the propeller generates on the shaft and on the ship hull.The first part of the text is devoted to fundamentals of the flow about hydrofoil sections (with and without cavitation...... of an intermittently cavitating propeller in a wake and the pressures and forces it exerts on the shaft and on the ship hull is examined. A final chapter discusses the optimization of efficiency of compound propulsors. The authors have taken care to clearly describe physical concepts and mathematical steps. Appendices...

  16. Foundations of radiation hydrodynamics

    CERN Document Server

    Mihalas, Dimitri

    1999-01-01

    Radiation hydrodynamics is a broad subject that cuts across many disciplines in physics and astronomy: fluid dynamics, thermodynamics, statistical mechanics, kinetic theory, and radiative transfer, among others. The theory developed in this book by two specialists in the field can be applied to the study of such diverse astrophysical phenomena as stellar winds, supernova explosions, and the initial phases of cosmic expansion, as well as the physics of laser fusion and reentry vehicles. As such, it provides students with the basic tools for research on radiating flows.Largely self-contained,

  17. Radiographic enhancement and analysis system

    International Nuclear Information System (INIS)

    Schlosser, M.S.

    1981-01-01

    Radiographic image enhancement and analysis techniques are discussed as they apply to nondestructive inspection. A system is described which has been developed to enhance and quantitatively evaluate radiographic images using digital computer techniques. Some examples of typical applications are also presented as an introduction to this new inspection technique. (author)

  18. Interpretation and digestion of radiograph

    International Nuclear Information System (INIS)

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

    2008-01-01

    Radiography digestion is final test for the radiography to make sure that radiograph produced will inspect their quality of the image before its interpreted. This level is critical level where if there is a mistake, all of the radiography work done before will be unaccepted. So as mention earlier, it can waste time, cost and more worst it can make the production must shut down. So, this step, level two radiographers or interpreter must evaluate the radiograph carefully. For this purpose, digestion room and densitometer must used. Of course all the procedure must follow the specification that mentioned in document. There are several needs must fill before we can say the radiograph is corrected or not like the location of penetrameter, number of penetrameter that showed, the degree of density of film, and usually there is no problem in this step and the radiograph can go to interpretation and evaluation step as will mentioned in next chapter.

  19. Chesneys' radiographic imaging. 5. ed.

    International Nuclear Information System (INIS)

    Ball, J.; Price, T.

    1989-01-01

    This new edition of Chesney and Chesney: Radiographic Imaging has been completely written by two new authors. The book reflects the change in emphasis in radiology from photographic processes towards electronic imaging methods. There is new material on image intensifiers and television imaging, digital imaging and digital subtractions. Analyses of the various characteristics of, and defects in, images on radiographs, xeroradiographs and the television screen are included. The methods, equipment and materials used to record the cathode ray tube image are described and there is new material on the principles of alternative diagnostic imaging techniques such as ultrasound, computed tomography and radionuclide imaging which provide cathode ray tube images. The book is primarily for student radiographers studying for the Diploma of the College of Radiographers, but radiographers studying for postdiplomate qualifications such as the Higher Diploma (HDCR) will also find the book helpful. (author)

  20. Nanoscale hydrodynamics near solids

    Science.gov (United States)

    Camargo, Diego; de la Torre, J. A.; Duque-Zumajo, D.; Español, Pep; Delgado-Buscalioni, Rafael; Chejne, Farid

    2018-02-01

    Density Functional Theory (DFT) is a successful and well-established theory for the study of the structure of simple and complex fluids at equilibrium. The theory has been generalized to dynamical situations when the underlying dynamics is diffusive as in, for example, colloidal systems. However, there is no such a clear foundation for Dynamic DFT (DDFT) for the case of simple fluids in contact with solid walls. In this work, we derive DDFT for simple fluids by including not only the mass density field but also the momentum density field of the fluid. The standard projection operator method based on the Kawasaki-Gunton operator is used for deriving the equations for the average value of these fields. The solid is described as featureless under the assumption that all the internal degrees of freedom of the solid relax much faster than those of the fluid (solid elasticity is irrelevant). The fluid moves according to a set of non-local hydrodynamic equations that include explicitly the forces due to the solid. These forces are of two types, reversible forces emerging from the free energy density functional, and accounting for impenetrability of the solid, and irreversible forces that involve the velocity of both the fluid and the solid. These forces are localized in the vicinity of the solid surface. The resulting hydrodynamic equations should allow one to study dynamical regimes of simple fluids in contact with solid objects in isothermal situations.

  1. Anisotropic nonequilibrium hydrodynamic attractor

    Science.gov (United States)

    Strickland, Michael; Noronha, Jorge; Denicol, Gabriel S.

    2018-02-01

    We determine the dynamical attractors associated with anisotropic hydrodynamics (aHydro) and the DNMR equations for a 0 +1 d conformal system using kinetic theory in the relaxation time approximation. We compare our results to the nonequilibrium attractor obtained from the exact solution of the 0 +1 d conformal Boltzmann equation, the Navier-Stokes theory, and the second-order Mueller-Israel-Stewart theory. We demonstrate that the aHydro attractor equation resums an infinite number of terms in the inverse Reynolds number. The resulting resummed aHydro attractor possesses a positive longitudinal-to-transverse pressure ratio and is virtually indistinguishable from the exact attractor. This suggests that an optimized hydrodynamic treatment of kinetic theory involves a resummation not only in gradients (Knudsen number) but also in the inverse Reynolds number. We also demonstrate that the DNMR result provides a better approximation of the exact kinetic theory attractor than the Mueller-Israel-Stewart theory. Finally, we introduce a new method for obtaining approximate aHydro equations which relies solely on an expansion in the inverse Reynolds number. We then carry this expansion out to the third order, and compare these third-order results to the exact kinetic theory solution.

  2. Load responsive hydrodynamic bearing

    Science.gov (United States)

    Kalsi, Manmohan S.; Somogyi, Dezso; Dietle, Lannie L.

    2002-01-01

    A load responsive hydrodynamic bearing is provided in the form of a thrust bearing or journal bearing for supporting, guiding and lubricating a relatively rotatable member to minimize wear thereof responsive to relative rotation under severe load. In the space between spaced relatively rotatable members and in the presence of a liquid or grease lubricant, one or more continuous ring shaped integral generally circular bearing bodies each define at least one dynamic surface and a plurality of support regions. Each of the support regions defines a static surface which is oriented in generally opposed relation with the dynamic surface for contact with one of the relatively rotatable members. A plurality of flexing regions are defined by the generally circular body of the bearing and are integral with and located between adjacent support regions. Each of the flexing regions has a first beam-like element being connected by an integral flexible hinge with one of the support regions and a second beam-like element having an integral flexible hinge connection with an adjacent support region. A least one local weakening geometry of the flexing region is located intermediate the first and second beam-like elements. In response to application of load from one of the relatively rotatable elements to the bearing, the beam-like elements and the local weakening geometry become flexed, causing the dynamic surface to deform and establish a hydrodynamic geometry for wedging lubricant into the dynamic interface.

  3. Hydrodynamic Forces on Composite Structures

    Science.gov (United States)

    2014-06-01

    NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release; distribution is unlimited HYDRODYNAMIC ...Thesis 4. TITLE AND SUBTITLE HYDRODYNAMIC FORCES ON COMPOSITE STRUCTURES 5. FUNDING NUMBERS 6. AUTHOR(S) Scott C. Millhouse 7. PERFORMING...angles yields different free surface effects including vortices and the onset of cavitation . 14. SUBJECT TERMS Fluid structure interaction, FSI, finite

  4. Black brane entropy and hydrodynamics

    NARCIS (Netherlands)

    Booth, I.; Heller, M.P.; Spaliński, M.

    2010-01-01

    A generalization of entropy to near-equilibrium phenomena is provided by the notion of a hydrodynamic entropy current. Recent advances in holography have lead to the formulation of fluid-gravity duality, a remarkable connection between the hydrodynamics of certain strongly coupled media and dynamics

  5. Black brane entropy and hydrodynamics

    NARCIS (Netherlands)

    Booth, I.; Heller, M.P.; Spaliński, M.

    2011-01-01

    A generalization of entropy to near-equilibrium phenomena is provided by the notion of a hydrodynamic entropy current. Recent advances in holography have lead to the formulation of fluid-gravity duality, a remarkable connection between the hydrodynamics of certain strongly coupled media and dynamics

  6. A hydrodynamic formalism for Brownian systems

    International Nuclear Information System (INIS)

    Pina, E.; Rosales, M.A.

    1981-01-01

    A formal hydrodynamic approach to Brownian motion is presented and the corresponding equations are derived. Hydrodynamic quantities are expressed in terms of the physical variables characterizing the Brownian systems. Contact is made with the hydrodynamic model of Quantum Mechanics. (author)

  7. Radiographic scanner apparatus

    International Nuclear Information System (INIS)

    Wake, R.H.

    1980-01-01

    The preferred embodiment of this invention includes a hardware system, or processing means, which operates faster than software. Moreover the computer needed is less expensive and smaller. Radiographic scanner apparatus is described for measuring the intensity of radiation after passage through a planar region and for reconstructing a representation of the attenuation of radiation by the medium. There is a source which can be rotated, and detectors, the output from which forms a data line. The detectors are disposed opposite the planar region from the source to produce a succession of data lines corresponding to the succession of angular orientations of the source. There is a convolver means for convolving each of these data lines, with a filter function, and a means of processing the convolved data lines to create the representation of the radiation attenuation in the planar region. There is also apparatus to generate a succession of data lines indicating radiation attenuation along a determinable path with convolver means. (U.K.)

  8. Foundations of radiation hydrodynamics

    Science.gov (United States)

    Mihalas, D.; Mihalas, B. W.

    This book is the result of an attempt, over the past few years, to gather the basic tools required to do research on radiating flows in astrophysics. The microphysics of gases is discussed, taking into account the equation of state of a perfect gas, the first and second law of thermodynamics, the thermal properties of a perfect gas, the distribution function and Boltzmann's equation, the collision integral, the Maxwellian velocity distribution, Boltzmann's H-theorem, the time of relaxation, and aspects of classical statistical mechanics. Other subjects explored are related to the dynamics of ideal fluids, the dynamics of viscous and heat-conducting fluids, relativistic fluid flow, waves, shocks, winds, radiation and radiative transfer, the equations of radiation hydrodynamics, and radiating flows. Attention is given to small-amplitude disturbances, nonlinear flows, the interaction of radiation and matter, the solution of the transfer equation, acoustic waves, acoustic-gravity waves, basic concepts of special relativity, and equations of motion and energy.

  9. From TDHF to hydrodynamics

    International Nuclear Information System (INIS)

    Koehler, H.S.

    1983-01-01

    The Time-Dependent Hartree-Fock theory provides a microscopic approach to the scattering of heavy ions. Fundamental in this theory is a mean-(one-body) field. The calculation of this field from a two-body effective interaction makes the theory microscopic. Many-body effects are included by the Brueckner definition of this interaction; the reaction-matrix. In excited media it is in general complex allowing for decays. The imaginary part relates directly to the collision-term in a transport equation. We treat this term by the time-relaxation-method. This implies an extension of the TDHF-equation to include two-body collisions. Hydrodynamic equations are derived from this new equation. The solution of the two equations agree quantitatively for short-relaxation-times. Relaxation-times are calculated as a function of temperature. (orig.)

  10. Hydrodynamics of Peristaltic Propulsion

    Science.gov (United States)

    Athanassiadis, Athanasios; Hart, Douglas

    2014-11-01

    A curious class of animals called salps live in marine environments and self-propel by ejecting vortex rings much like jellyfish and squid. However, unlike other jetting creatures that siphon and eject water from one side of their body, salps produce vortex rings by pumping water through siphons on opposite ends of their hollow cylindrical bodies. In the simplest cases, it seems like some species of salp can successfully move by contracting just two siphons connected by an elastic body. When thought of as a chain of timed contractions, salp propulsion is reminiscent of peristaltic pumping applied to marine locomotion. Inspired by salps, we investigate the hydrodynamics of peristaltic propulsion, focusing on the scaling relationships that determine flow rate, thrust production, and energy usage in a model system. We discuss possible actuation methods for a model peristaltic vehicle, considering both the material and geometrical requirements for such a system.

  11. Hydrodynamic effects on coalescence.

    Energy Technology Data Exchange (ETDEWEB)

    Dimiduk, Thomas G.; Bourdon, Christopher Jay; Grillet, Anne Mary; Baer, Thomas A.; de Boer, Maarten Pieter; Loewenberg, Michael (Yale University, New Haven, CT); Gorby, Allen D.; Brooks, Carlton, F.

    2006-10-01

    The goal of this project was to design, build and test novel diagnostics to probe the effect of hydrodynamic forces on coalescence dynamics. Our investigation focused on how a drop coalesces onto a flat surface which is analogous to two drops coalescing, but more amenable to precise experimental measurements. We designed and built a flow cell to create an axisymmetric compression flow which brings a drop onto a flat surface. A computer-controlled system manipulates the flow to steer the drop and maintain a symmetric flow. Particle image velocimetry was performed to confirm that the control system was delivering a well conditioned flow. To examine the dynamics of the coalescence, we implemented an interferometry capability to measure the drainage of the thin film between the drop and the surface during the coalescence process. A semi-automated analysis routine was developed which converts the dynamic interferogram series into drop shape evolution data.

  12. The radiographic image: A cultural artefact?

    International Nuclear Information System (INIS)

    Strudwick, Ruth M.

    2014-01-01

    This article looks at the role of the radiographic images produced by diagnostic radiographers. An ethnographic study of the workplace culture in one diagnostic imaging department was undertaken using participant observation for four months and semi-structured interviews with ten key informants. One of the key themes; that of the radiographic image as a cultural artefact, is explored in this article. The radiographic image is a cultural artefact which radiographers are protective of and take ownership of. Radiographers are conscious of the quality of their images and the images are an important aspect of their work. Radiographers take criticism of their images personally. The radiographic image is a record of the interaction that occurs between the radiographer and the patient. The way in which radiographic images are viewed, used and judged is an important aspect of the role of diagnostic radiographer

  13. Radiographic film cassette unloading apparatus

    International Nuclear Information System (INIS)

    Stievenart, E.F.; Plessers, H.S.; Neujens, G.J.

    1980-01-01

    Apparatus for unloading cassettes, containing exposed radiographic films, has means for unfastening the cassettes, an inclined pathway for gravity feeding and rotating feed members (rollers or belts) to propel the films into the processor. (UK)

  14. Method for taking X radiographs

    International Nuclear Information System (INIS)

    Orth, G.

    1983-01-01

    The method is aimed at obtaining X radiographs of any human organ with the aid of an X-ray-shadowless radiation detector of a dose measuring device, which is arranged between patient and imaging system, and of a controlling microprocessor system, so that the image-forming parameters are automatically adjusted to the specific properties of the patient. This procedure minimices the efforts in preparing the radiograph and the radiation exposure of the patient

  15. Film holder for radiographing tubing

    International Nuclear Information System (INIS)

    Davis, E.V.; Foster, B.E.

    1976-01-01

    A film cassette is described which may be easily placed about tubing or piping and readily held in place while radiographic inspection is performed. A pair of precurved light-impervious semi-rigid plastic sheets, hinged at one edge, enclose sheet film together with any metallic foils or screens. Other edges are made light-tight with removable caps, and the entire unit is held securely about the object to be radiographed with a releasable fastener such as a strip of Velcro

  16. The radiographic manifestations of hypochondroplasia

    International Nuclear Information System (INIS)

    Heselson, N.G.; Cremin, B.J.; Beighton, P.

    1979-01-01

    Hypochrondroplasia is an inherited skeletal dysplasia that resembles achondroplasia in mild degree. Radiographic manifestations encountered in 12 affected individuals in South Africa include slight shortening of all segments of the tubular bones, moderate caudal diminution of the lumbar interpedicular distances, increased lumbar lordosis with cacral tilt and distal prolongation of the fibular. Hypochondroplasia can be distinguished from other osteochondrodystrophies such as achondroplasia, pseudo-achondroplasia and metaphyseal chondroplasia by the recognition of it clinical and radiographic manifestations. (author)

  17. Film holder for radiographing tubing

    Science.gov (United States)

    Davis, Earl V.; Foster, Billy E.

    1976-01-01

    A film cassette is provided which may be easily placed about tubing or piping and readily held in place while radiographic inspection is performed. A pair of precurved light-impervious semi-rigid plastic sheets, hinged at one edge, enclose sheet film together with any metallic foils or screens. Other edges are made light-tight with removable caps, and the entire unit is held securely about the object to be radiographed with a releasable fastener such as a strip of Velcro.

  18. Hydrodynamic cavitation for sonochemical effects.

    Science.gov (United States)

    Moholkar, V S; Kumar, P S; Pandit, A B

    1999-03-01

    A comparative study of hydrodynamic and acoustic cavitation has been made on the basis of numerical solutions of the Rayleigh-Plesset equation. The bubble/cavity behaviour has been studied under both acoustic and hydrodynamic cavitation conditions. The effect of varying pressure fields on the collapse of the cavity (sinusoidal for acoustic and linear for hydrodynamic) and also on the latter's dynamic behaviour has been studied. The variations of parameters such as initial cavity size, intensity of the acoustic field and irradiation frequency in the case of acoustic cavitation, and initial cavity size, final recovery pressure and time for pressure recovery in the case of hydrodynamic cavitation, have been found to have significant effects on cavity/bubble dynamics. The simulations reveal that the bubble/cavity collapsing behaviour in the case of hydrodynamic cavitation is accompanied by a large number of pressure pulses of relatively smaller magnitude, compared with just one or two pulses under acoustic cavitation. It has been shown that hydrodynamic cavitation offers greater control over operating parameters and the resultant cavitation intensity. Finally, a brief summary of the experimental results on the oxidation of aqueous KI solution with a hydrodynamic cavitation set-up is given which supports the conclusion of this numerical study. The methodology presented allows one to manipulate and optimise of specific process, either physical or chemical.

  19. Recent development of hydrodynamic modeling

    Science.gov (United States)

    Hirano, Tetsufumi

    2014-09-01

    In this talk, I give an overview of recent development in hydrodynamic modeling of high-energy nuclear collisions. First, I briefly discuss about current situation of hydrodynamic modeling by showing results from the integrated dynamical approach in which Monte-Carlo calculation of initial conditions, quark-gluon fluid dynamics and hadronic cascading are combined. In particular, I focus on rescattering effects of strange hadrons on final observables. Next I highlight three topics in recent development in hydrodynamic modeling. These include (1) medium response to jet propagation in di-jet asymmetric events, (2) causal hydrodynamic fluctuation and its application to Bjorken expansion and (3) chiral magnetic wave from anomalous hydrodynamic simulations. (1) Recent CMS data suggest the existence of QGP response to propagation of jets. To investigate this phenomenon, we solve hydrodynamic equations with source term which exhibits deposition of energy and momentum from jets. We find a large number of low momentum particles are emitted at large angle from jet axis. This gives a novel interpretation of the CMS data. (2) It has been claimed that a matter created even in p-p/p-A collisions may behave like a fluid. However, fluctuation effects would be important in such a small system. We formulate relativistic fluctuating hydrodynamics and apply it to Bjorken expansion. We found the final multiplicity fluctuates around the mean value even if initial condition is fixed. This effect is relatively important in peripheral A-A collisions and p-p/p-A collisions. (3) Anomalous transport of the quark-gluon fluid is predicted when extremely high magnetic field is applied. We investigate this possibility by solving anomalous hydrodynamic equations. We found the difference of the elliptic flow parameter between positive and negative particles appears due to the chiral magnetic wave. Finally, I provide some personal perspective of hydrodynamic modeling of high energy nuclear collisions

  20. SPECIAL RELATIVISTIC HYDRODYNAMICS WITH GRAVITATION

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Jai-chan [Department of Astronomy and Atmospheric Sciences, Kyungpook National University, Daegu (Korea, Republic of); Noh, Hyerim [Korea Astronomy and Space Science Institute, Daejon (Korea, Republic of)

    2016-12-20

    Special relativistic hydrodynamics with weak gravity has hitherto been unknown in the literature. Whether such an asymmetric combination is possible has been unclear. Here, the hydrodynamic equations with Poisson-type gravity, considering fully relativistic velocity and pressure under the weak gravity and the action-at-a-distance limit, are consistently derived from Einstein’s theory of general relativity. An analysis is made in the maximal slicing, where the Poisson’s equation becomes much simpler than our previous study in the zero-shear gauge. Also presented is the hydrodynamic equations in the first post-Newtonian approximation, now under the general hypersurface condition. Our formulation includes the anisotropic stress.

  1. Similarity flows in relativistic hydrodynamics

    International Nuclear Information System (INIS)

    Blaizot, J.P.; Ollitrault, J.Y.

    1986-01-01

    In ultra-relativistic heavy ion collisions, one expects in particular to observe a deconfinement transition leading to a formation of quark gluon plasma. In the framework of the hydrodynamic model, experimental signatures of such a plasma may be looked for as observable consequences of a first order transition on the evolution of the system. In most of the possible scenario, the phase transition is accompanied with discontinuities in the hydrodynamic flow, such as shock waves. The method presented in this paper has been developed to treat without too much numerical effort such discontinuous flow. It relies heavily on the use of similarity solutions of the hydrodynamic equations

  2. Radiographic examination of the equine head

    International Nuclear Information System (INIS)

    Park, R.D.

    1993-01-01

    Radiographic examinations of the equine head can be performed with portable x-ray machines. The views comprising the examination depend on the area of the head being examined. With a knowledge of radiographic anatomy and radiographic signs of disease, valuable diagnostic information can be obtained from the radiographic examination. In addition, the radiographic information can also be used to develop a prognosis and determine the most appropriate therapy

  3. Radiographic testing at Lawrence Livermore National Laboratory

    International Nuclear Information System (INIS)

    Bossi, R.H.

    1982-01-01

    Radiographic testing is a nondestructive inspection technique which uses penetrating radiation. The Nondestructive Evaluation (NDE) Section at Lawrence Livermore National Laboratory has a broad spectrum of equipment and techniques for radiographic testing. These resources include low-energy vacuum systems, low- and mid-energy cabinet and cell radiographic systems, high-energy linear accelerators, portable x-ray machines and radioisotopes for radiographic inspections. For diagnostic testing the NDE Section also has real-time and flash radiographic equipment

  4. Lotic Water Hydrodynamic Model

    Energy Technology Data Exchange (ETDEWEB)

    Judi, David Ryan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tasseff, Byron Alexander [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-01-23

    Water-related natural disasters, for example, floods and droughts, are among the most frequent and costly natural hazards, both socially and economically. Many of these floods are a result of excess rainfall collecting in streams and rivers, and subsequently overtopping banks and flowing overland into urban environments. Floods can cause physical damage to critical infrastructure and present health risks through the spread of waterborne diseases. Los Alamos National Laboratory (LANL) has developed Lotic, a state-of-the-art surface water hydrodynamic model, to simulate propagation of flood waves originating from a variety of events. Lotic is a two-dimensional (2D) flood model that has been used primarily for simulations in which overland water flows are characterized by movement in two dimensions, such as flood waves expected from rainfall-runoff events, storm surge, and tsunamis. In 2013, LANL developers enhanced Lotic through several development efforts. These developments included enhancements to the 2D simulation engine, including numerical formulation, computational efficiency developments, and visualization. Stakeholders can use simulation results to estimate infrastructure damage and cascading consequences within other sets of infrastructure, as well as to inform the development of flood mitigation strategies.

  5. Hydrodynamics of rotating superfluids

    International Nuclear Information System (INIS)

    Chandler, E.A.

    1981-01-01

    In this thesis, a coarse grained hydrodynamics is developed from the exact description of Tkachenko. To account for the dynamics of the vortex lattice, the macroscopic vortex displacement field is treated as an independent degree of freedom. The conserved energy is written in terms of the coarse-grained normal fluid, superfluid, and vortex velocities and includes an elastic energy associated with deformations of the vortex lattice. Equations of motion consistent with the conservation of energy, entropy and vorticity and containing mutual friction terms arising from microscopic interactions between normal fluid excitations and the vortex lines are derived. When the vortex velocity is eliminated from the damping terms, this system of equations becomes essentially that of BK with added elastic terms in the momentum stress tensor and energy current. The dispersion relation and damping of the first and second sound modes and the two transverse modes sustained by the system are investigated. It is shown that mutual friction mixes the transverse modes of the normal and superfluid components and damps the transverse mode associated with the relative velocity of these components, making this wave evanescent in the plane perpendicular to the rotation axis. The wave associated with transverse motion of the total mass current is a generalized Tkachenko mode, whose dispersion relation reduces to that derived by Tkachenko wave when the wavevector lies in this plane

  6. Advanced in Macrostatistical Hydrodynamics

    International Nuclear Information System (INIS)

    Graham, A.L.; Tetlow, N.; Abbott, J.R.; Mondy, L.S.; Brenner, H.

    1993-01-01

    An overview is presented of research that focuses on slow flows of suspensions in which colloidal and inertial effects are negligibly small (Macrostatistical Hydrodynamics). First, we describe nuclear magnetic resonance imaging experiments to quantitatively measure particle migration occurring in concentrated suspensions undergoing a flow with a nonuniform shear rate. These experiments address the issue of how the flow field affects the microstructure of suspensions. In order to understand the local viscosity in a suspension with such a flow-induced, spatially varying concentration, one must know how the viscosity of a homogeneous suspension depends on such variables as solids concentration and particle orientation. We suggest the technique of falling ball viscometry, using small balls, as a method to determine the effective viscosity of a suspension without affecting the original microstructure significantly. We also describe data from experiments in which the detailed fluctuations of a falling ball's velocity indicate the noncontinuum nature of the suspension and may lead to more insights into the effects of suspension microstructure on macroscopic properties. Finally, we briefly describe other experiments that can be performed in quiescent suspensions (in contrast to the use of conventional shear rotational viscometers) in order to learn more about the microstructure and boundary effects in concentrated suspensions

  7. Engineering Hydrodynamic AUV Hulls

    Science.gov (United States)

    Allen, J.

    2016-12-01

    AUV stands for autonomous underwater vehicle. AUVs are used in oceanography and are similar to gliders. MBARIs AUVs as well as other AUVs map the ocean floor which is very important. They also measure physical characteristics of the water, such as temperature and salinity. My science fair project for 4th grade was a STEM activity in which I built and tested 3 different AUV bodies. I wanted to find out which design was the most hydrodynamic. I tested three different lengths of AUV hulls to see which AUV would glide the farthest. The first was 6 inches. The second was 12 inches and the third was 18 inches. I used clay for the nosecone and cut a ruler into two and made it the fin. Each AUV used the same nosecone and fin. I tested all three designs in a pool. I used biomimicry to create my hypothesis. When I was researching I found that long slim animals swim fastest. So, my hypothesis is the longer AUV will glide farthest. In the end I was right. The longer AUV did glide the farthest.

  8. Reproductive health of male radiographers

    International Nuclear Information System (INIS)

    Shakhatreh, Farouk M.

    2001-01-01

    To compare certain reproductive health problems reported in 2 groups of males, one of which was exposed to x-ray radiation (radiographers) and the other group that was not exposed to x-ray radiation. The reproductive health problems were miscarriage, congenital anomalies, still births and infertility. Two groups of men were selected (90 in each group). The first group consisted of radiographers and the other groups consisted of men not exposed to x-ray radiation. The 2 groups were matched for age and source. Relative risk, attributable risk percentage and level of significance were calculated. Incidence rate of reproductive health problems was increasing with the increase in duration of exposure to x-ray radiation ranging between 17% (for those exposed for 1-5 years) to 91% (for those exposed for more than 15 years). There were significant associations between exposure to radiation and miscarriage (relative risk = 1.67, attributable risk percentage = 40%), congenital anomalies (relative risk = 10, attributable risk percentage 90%), still birth (relative risk = 7, attributable risk percentage = 86%), and infertility (relative risk = 4.5, attributable risk = 78%). The incidence rates of reproductive health problems reported by male radiographers were significantly higher than that reported by the non exposed group and higher than the incidence rates reported in community-based studies in Jordan. The incidence rates of fetal death (miscarriage and stillbirth together) and infertility reported by our radiographers were higher than had been reported by the British radiographers. An immediate plan of action is needed to protect our radiographers. Further studies are needed in this field taking into account all extraneous variables that may affect the reproductive health of radiographers. (author)

  9. Hydrodynamics of electrons in graphene

    Science.gov (United States)

    Lucas, Andrew; Chung Fong, Kin

    2018-02-01

    Generic interacting many-body quantum systems are believed to behave as classical fluids on long time and length scales. Due to rapid progress in growing exceptionally pure crystals, we are now able to experimentally observe this collective motion of electrons in solid-state systems, including graphene. We present a review of recent progress in understanding the hydrodynamic limit of electronic motion in graphene, written for physicists from diverse communities. We begin by discussing the ‘phase diagram’ of graphene, and the inevitable presence of impurities and phonons in experimental systems. We derive hydrodynamics, both from a phenomenological perspective and using kinetic theory. We then describe how hydrodynamic electron flow is visible in electronic transport measurements. Although we focus on graphene in this review, the broader framework naturally generalizes to other materials. We assume only basic knowledge of condensed matter physics, and no prior knowledge of hydrodynamics.

  10. Analytic approaches to relativistic hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Hatta, Yoshitaka

    2016-12-15

    I summarize our recent work towards finding and utilizing analytic solutions of relativistic hydrodynamic. In the first part I discuss various exact solutions of the second-order conformal hydrodynamics. In the second part I compute flow harmonics v{sub n} analytically using the anisotropically deformed Gubser flow and discuss its dependence on n, p{sub T}, viscosity, the chemical potential and the charge.

  11. Hydrodynamic aspects of flotation separation

    Directory of Open Access Journals (Sweden)

    Peleka Efrosyni N.

    2016-01-01

    Full Text Available Flotation separation is mainly used for removing particulates from aqueous dispersions. It is widely used for ore beneficiation and recovering valuable materials. This paper reviews the hydrodynamics of flotation separations and comments on selected recent publications. Units are distinguished as cells of ideal and non-ideal flow. A brief introduction to hydrodynamics is included to explain an original study of the hybrid flotation-microfiltration cell, effective for heavy metal ion removal.

  12. An introduction to astrophysical hydrodynamics

    CERN Document Server

    Shore, Steven N

    1992-01-01

    This book is an introduction to astrophysical hydrodynamics for both astronomy and physics students. It provides a comprehensive and unified view of the general problems associated with fluids in a cosmic context, with a discussion of fluid dynamics and plasma physics. It is the only book on hydrodynamics that addresses the astrophysical context. Researchers and students will find this work to be an exceptional reference. Contents include chapters on irrotational and rotational flows, turbulence, magnetohydrodynamics, and instabilities.

  13. A radiographic study of mental foramen in intraoral radiographs

    International Nuclear Information System (INIS)

    Sohn, Jeong Ick; Choi, Karp Shik

    1995-01-01

    The purpose of this study was to evaluate the position and shape of mental foramen in periapical radiographs. For this study, periapical radiographs of premolar areas were obtained from the 200 adults. Accordingly, the positional and shape changes of mental foramen were evaluated. The authors obtained radiographs according to changes in radiation beam direction in periapical radiographs of premolar areas, and then evaluated the positional and shape changes of mental foramen. The following results were obtained: 1. Shapes of mental foramen were observed elliptical (34.3%), round or oval (28.0%), unidentified (25.5%) and diffuse (12.2%) type in descending order of frequency. 2, Horizontal positions of mental foramen were most frequently observed at the 2nd premolar area (55.3%), the area between the 1st premolar and 2nd premolar (39.6%), the area between the 2nd premolar and 1st molar (3.4%), the 1st premolar area (1.0%), the area between the canine and 1st premolar (0.7%) in descending order of frequency. 3. Vertical positions of mental foramen were most frequently observed at the inferior to apex (67.1%), and at apex (24.8%), overlap with apex (6.4%), superior to apex (1.7%) in descending order of frequency. 4. Shapes of mental foramen were more obviously observed at the upward 10 degree positioned periapical radiographs. And according to the changes of horizontal and vertical position, they were observed similar to normally positioned periapical radiographs.

  14. Attitudes of radiographers to radiographer-led discharge: A survey

    International Nuclear Information System (INIS)

    Lumsden, Laura; Cosson, Philip

    2015-01-01

    Background: The traditional role of the Diagnostic Radiographer in image acquisition has gradually been extended through skill-mix, particularly to include abnormality detection. Aims: This research focused on the attitudes of Radiographers to Radiographer-led Discharge (RLD), where Radiographers discharge patients with minor injuries and perform tasks previously undertaken by Accident and Emergency staff. The effects of job role, hospital type, experience and whether RLD was used in the participant's trust were examined. Method: A multiple-indicator online questionnaire assessed attitudes to RLD. Snowball sampling was used with advertisement via emails, posters and cards, containing Quick Response (QR) codes. Statement responses were coded, with reverse coding for negative statements and total scores were calculated. A higher score represented a more positive attitude. Results: 101 questionnaires were completed (an estimated 30% response rate) and the mean total score was 84/115. 95% of participants supported radiographer involvement in abnormality detection, with 46.5% selecting RLD as the preferred system for minor injuries patients vs 48.5% preferring commenting alone. Discussion: Participants were positive about extending their role through RLD and felt confident in their image interpretation abilities, though expressed concern for the legal consequences of the role and adequate pay. Generalization of the results is limited due to the possible low response rate. Conclusion: Overall, participants demonstrated positive attitudes towards RLD but they also indicate the need for appropriate payment for any additional responsibility. These findings are promising for successful implementation of RLD, though larger-scale research including radiologists, business managers, A and E staff and patients would be beneficial. - Highlights: • 101 questionnaires were completed (an estimated 30% response rate). • 95% of participants supported radiographer involvement

  15. CALIBRATED HYDRODYNAMIC MODEL

    Directory of Open Access Journals (Sweden)

    Sezar Gülbaz

    2015-01-01

    Full Text Available The land development and increase in urbanization in a watershed affect water quantityand water quality. On one hand, urbanization provokes the adjustment of geomorphicstructure of the streams, ultimately raises peak flow rate which causes flood; on theother hand, it diminishes water quality which results in an increase in Total SuspendedSolid (TSS. Consequently, sediment accumulation in downstream of urban areas isobserved which is not preferred for longer life of dams. In order to overcome thesediment accumulation problem in dams, the amount of TSS in streams and inwatersheds should be taken under control. Low Impact Development (LID is a BestManagement Practice (BMP which may be used for this purpose. It is a land planningand engineering design method which is applied in managing storm water runoff inorder to reduce flooding as well as simultaneously improve water quality. LID includestechniques to predict suspended solid loads in surface runoff generated over imperviousurban surfaces. In this study, the impact of LID-BMPs on surface runoff and TSS isinvestigated by employing a calibrated hydrodynamic model for Sazlidere Watershedwhich is located in Istanbul, Turkey. For this purpose, a calibrated hydrodynamicmodel was developed by using Environmental Protection Agency Storm WaterManagement Model (EPA SWMM. For model calibration and validation, we set up arain gauge and a flow meter into the field and obtain rainfall and flow rate data. Andthen, we select several LID types such as retention basins, vegetative swales andpermeable pavement and we obtain their influence on peak flow rate and pollutantbuildup and washoff for TSS. Consequently, we observe the possible effects ofLID on surface runoff and TSS in Sazlidere Watershed.

  16. Caries detection in dental radiographs

    International Nuclear Information System (INIS)

    Dunn, S.M.

    1987-01-01

    Caries, or the decay of teeth are difficult to automatically detect in dental radiographs because of the small area of the image that is occupied by the decay. Images of dental radiographs has distinct regions of homogeneous gray levels, and therefore naturally lead to a segmentation based automatic caries detection algorithm. This paper describes a method for caries detection based on a multiclass, area independent thresholding and segmenting scheme. This multiclass thresholding algorithm is an extension of the uniform error threshold, an area independent, distribution free thresholding method used for images of only two classes of objects. The authors first consider the problem of caries detection and the image features that characterize the presence of caries. Next, the uniform error threshold is reviewed, and the general multiclass uniform error threshold algorithm is presented. This algorithm is used to automatically detect caries in dental radiographs

  17. Interpretation and evaluation of radiograph

    International Nuclear Information System (INIS)

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

    2008-01-01

    After digestion, the interpreter must interpreted and evaluate the image on film, usually many radiograph stuck in this step, if there is good density, so there are no problem. This is a final stage of radiography work and this work must be done by level two or three radiographer. This is a final stages before the radiographer give a result to their customer for further action. The good interpreter must know what kind of artifact, is this artifact are dangerous or not and others. In this chapter, the entire artifact that usually showed will be discussed briefly with the good illustration and picture to make the reader understand and know the type of artifact that exists.

  18. Industrial radiography on radiographic paper

    International Nuclear Information System (INIS)

    Domanus, J.C.

    1977-11-01

    An investigation was performed to compare the quality of radiographic paper with that of X-ray film, after a review had been made of the rather scarce literature on the subject. The equipment used throughout the investigation is described, and characteristic curves for Agfa-Gevaert and Kodak papers exposed with different intensifying screens in the low and intermediate voltage range are reproduced. The relative speed, contrast and exposure latitude were computed from these curves. The quality of the radiographic image was checked on U/Al blocks and plates, Al and Fe blocks, and fiber-reinforced composites. Exposure charts for Al and Fe were made for various paper and screen combinations. Both the sharpness of the radiographic image as well as the influence of processing on speed and contrast were checked. Examples are given of the practical application of the paper for radiography of castings, weldings, solderings, assemblies, etc. (author)

  19. Hydrodynamic escape from planetary atmospheres

    Science.gov (United States)

    Tian, Feng

    Hydrodynamic escape is an important process in the formation and evolution of planetary atmospheres. Due to the existence of a singularity point near the transonic point, it is difficult to find transonic steady state solutions by solving the time-independent hydrodynamic equations. In addition to that, most previous works assume that all energy driving the escape flow is deposited in one narrow layer. This assumption not only results in less accurate solutions to the hydrodynamic escape problem, but also makes it difficult to include other chemical and physical processes in the hydrodynamic escape models. In this work, a numerical model describing the transonic hydrodynamic escape from planetary atmospheres is developed. A robust solution technique is used to solve the time dependent hydrodynamic equations. The method has been validated in an isothermal atmosphere where an analytical solution is available. The hydrodynamic model is applied to 3 cases: hydrogen escape from small orbit extrasolar planets, hydrogen escape from a hydrogen rich early Earth's atmosphere, and nitrogen/methane escape from Pluto's atmosphere. Results of simulations on extrasolar planets are in good agreement with the observations of the transiting extrasolar planet HD209458b. Hydrodynamic escape of hydrogen from other hypothetical close-in extrasolar planets are simulated and the influence of hydrogen escape on the long-term evolution of these extrasolar planets are discussed. Simulations on early Earth suggest that hydrodynamic escape of hydrogen from a hydrogen rich early Earth's atmosphere is about two orders magnitude slower than the diffusion limited escape rate. A hydrogen rich early Earth's atmosphere could have been maintained by the balance between the hydrogen escape and the supply of hydrogen into the atmosphere by volcanic outgassing. Origin of life may have occurred in the organic soup ocean created by the efficient formation of prebiotic molecules in the hydrogen rich early

  20. Digital image analysis of NDT radiographs

    International Nuclear Information System (INIS)

    Graeme, W.A. Jr.; Eizember, A.C.; Douglass, J.

    1989-01-01

    Prior to the introduction of Charge Coupled Device (CCD) detectors the majority of image analysis performed on NDT radiographic images was done visually in the analog domain. While some film digitization was being performed, the process was often unable to capture all the usable information on the radiograph or was too time consuming. CCD technology now provides a method to digitize radiographic film images without losing the useful information captured in the original radiograph in a timely process. Incorporating that technology into a complete digital radiographic workstation allows analog radiographic information to be processed, providing additional information to the radiographer. Once in the digital domain, that data can be stored, and fused with radioscopic and other forms of digital data. The result is more productive analysis and management of radiographic inspection data. The principal function of the NDT Scan IV digital radiography system is the digitization, enhancement and storage of radiographic images

  1. PACS influence the radiographer's work

    International Nuclear Information System (INIS)

    Fridell, Kent; Aspelin, Peter; Edgren, Lars; Lindskoeld, Lars; Lundberg, Nina

    2009-01-01

    Radiological departments are changing rapidly due to the implementation of digital images and PACS (Picture Archiving and Communication Systems). The introduction of new technology seems to dissolve boundaries between the professions in the work environment where the technology is introduced. This process tends to change the organization and its routines. The aim of this qualitative study is to explore changes in radiographers' work with regard to skills, work practice and technology. The study used open-ended interviews to explore the radiographers' perceptions of such changes, and to identify problems and solutions pertaining to work practice. Inspiration is taken from grounded theory to explain the changes in work that were found. Respondents were selected from a total of 133 potential participants as a theoretical or purposive sample. The changing trends within the professional role indicated that radiographers, as image producers, shifted their focus from the ability to set the optimal exposure parameters in order to obtain the optimal image for diagnosis to become expert in exposure parameters, projection techniques and diagnostic practice, having multifaceted skills, as being the jack of all trades. When implementing PACS there was an obvious change in image production. At the start there were visions of new routines, and therefore the radiographers became early adopters to the new technology; in practice the organization was stacked in old routines, as the routines were inflexible and PACS work was pushed into old work routines. Although inflexible, this does not mean that they cannot change, and obviously in 2006 new routines had been implemented making it possible for the radiographers in finding new ways for collaborating with colleagues. The new technology immediately created a vision of improved service to the clinicians. In order to optimize the service the radiographers developed an insight into the need for a more comprehensive change in work using

  2. Radiographic testing in concrete structures

    International Nuclear Information System (INIS)

    Oliveira, D. de

    1987-01-01

    The radiographic testing done in concrete structures is used to analyse the homogeneity, position and corrosion of armatures and to detect discontinuity in the concrete such as: gaps, cracks and segregations. This work develops a Image quality Indicator (IQI) with an adequated sensibility to detect discontinuites based on BS4408 norm. (E.G.) [pt

  3. Soliton Gases and Generalized Hydrodynamics

    Science.gov (United States)

    Doyon, Benjamin; Yoshimura, Takato; Caux, Jean-Sébastien

    2018-01-01

    We show that the equations of generalized hydrodynamics (GHD), a hydrodynamic theory for integrable quantum systems at the Euler scale, emerge in full generality in a family of classical gases, which generalize the gas of hard rods. In this family, the particles, upon colliding, jump forward or backward by a distance that depends on their velocities, reminiscent of classical soliton scattering. This provides a "molecular dynamics" for GHD: a numerical solver which is efficient, flexible, and which applies to the presence of external force fields. GHD also describes the hydrodynamics of classical soliton gases. We identify the GHD of any quantum model with that of the gas of its solitonlike wave packets, thus providing a remarkable quantum-classical equivalence. The theory is directly applicable, for instance, to integrable quantum chains and to the Lieb-Liniger model realized in cold-atom experiments.

  4. Anomalous hydrodynamics of Weyl materials

    Science.gov (United States)

    Monteiro, Gustavo; Abanov, Alexander

    Kinetic theory is a useful tool to study transport in Weyl materials when the band-touching points are hidden inside a Fermi surface. It accounts, for example, for the negative magnetoresistance caused by the chiral magnetic effect and quantum oscillations (SdH effect) in the magnetoresistance together within the same framework. As an alternative approach to kinetic theory we also consider the regime of strong interactions where hydrodynamics can be applicable. A variational principle of these hydrodynamic equations can be found in and provide a natural framework to study hydrodynamic surface modes which correspond to the strongly-interacting physics signature of Fermi arcs. G.M. acknowledges the financial support from FAPESP.

  5. Brownian dynamics with hydrodynamic interactions

    International Nuclear Information System (INIS)

    Ermak, D.L.; McCammon, J.A.

    1978-01-01

    A method for simulating the Brownian dynamics of N particles with the inclusion of hydrodynamic interactions is described. The particles may also be subject to the usual interparticle or external forces (e.g., electrostatic) which have been included in previous methods for simulating Brownian dynamics of particles in the absence of hydrodynamic interactions. The present method is derived from the Langevin equations for the N particle assembly, and the results are shown to be consistent with the corresponding Fokker--Planck results. Sample calculations on small systems illustrate the importance of including hydrodynamic interactions in Brownian dynamics simulations. The method should be useful for simulation studies of diffusion limited reactions, polymer dynamics, protein folding, particle coagulation, and other phenomena in solution

  6. Abnormal pressures as hydrodynamic phenomena

    Science.gov (United States)

    Neuzil, C.E.

    1995-01-01

    So-called abnormal pressures, subsurface fluid pressures significantly higher or lower than hydrostatic, have excited speculation about their origin since subsurface exploration first encountered them. Two distinct conceptual models for abnormal pressures have gained currency among earth scientists. The static model sees abnormal pressures generally as relict features preserved by a virtual absence of fluid flow over geologic time. The hydrodynamic model instead envisions abnormal pressures as phenomena in which flow usually plays an important role. This paper develops the theoretical framework for abnormal pressures as hydrodynamic phenomena, shows that it explains the manifold occurrences of abnormal pressures, and examines the implications of this approach. -from Author

  7. Anisotropic hydrodynamics: Motivation and methodology

    Energy Technology Data Exchange (ETDEWEB)

    Strickland, Michael

    2014-06-15

    In this proceedings contribution I review recent progress in our understanding of the bulk dynamics of relativistic systems that possess potentially large local rest frame momentum-space anisotropies. In order to deal with these momentum-space anisotropies, a reorganization of relativistic viscous hydrodynamics can be made around an anisotropic background, and the resulting dynamical framework has been dubbed “anisotropic hydrodynamics”. I also discuss expectations for the degree of momentum-space anisotropy of the quark–gluon plasma generated in relativistic heavy ion collisions at RHIC and LHC from second-order viscous hydrodynamics, strong-coupling approaches, and weak-coupling approaches.

  8. Hydrodynamics of oceans and atmospheres

    CERN Document Server

    Eckart, Carl

    1960-01-01

    Hydrodynamics of Oceans and Atmospheres is a systematic account of the hydrodynamics of oceans and atmospheres. Topics covered range from the thermodynamic functions of an ideal gas and the thermodynamic coefficients for water to steady motions, the isothermal atmosphere, the thermocline, and the thermosphere. Perturbation equations, field equations, residual equations, and a general theory of rays are also presented. This book is comprised of 17 chapters and begins with an introduction to the basic equations and their solutions, with the aim of illustrating the laws of dynamics. The nonlinear

  9. Hydrodynamic constants from cosmic censorship

    International Nuclear Information System (INIS)

    Nakamura, Shin

    2008-01-01

    We study a gravity dual of Bjorken flow of N=4 SYM-theory plasma. We point out that the cosmic censorship hypothesis may explain why the regularity of the dual geometry constrains the hydrodynamic constants. We also investigate the apparent horizon of the dual geometry. We find that the dual geometry constructed on Fefferman-Graham (FG) coordinates is not appropriate for examination of the apparent horizon since the coordinates do not cover the trapped region. However, the preliminary analysis on FG coordinates suggests that the location of the apparent horizon is very sensitive to the hydrodynamic parameters. (author)

  10. Hydrodynamic simulation of elliptic flow

    CERN Document Server

    Kolb, P F; Ruuskanen, P V; Heinz, Ulrich W

    1999-01-01

    We use a hydrodynamic model to study the space-time evolution transverse to the beam direction in ultrarelativistic heavy-ion collisions with nonzero impact parameters. We focus on the influence of early pressure on the development of radial and elliptic flow. We show that at high energies elliptic flow is generated only during the initial stages of the expansion while radial flow continues to grow until freeze-out. Quantitative comparisons with SPS data from semiperipheral Pb+Pb collisions suggest the applicability of hydrodynamical concepts already $\\approx$ 1 fm/c after impact.

  11. Importance of radiographic monitoring of endoscopic sphincterotomy

    International Nuclear Information System (INIS)

    Greenberg, H.M.; Goldberg, H.I.; Shapiro, H.A.

    1981-01-01

    The radiographic features of endoscopic sphincterotomies performed in 44 patients were evaluated. Radiographic landmarks aided in proper sphincterotome placement and also disclosed conditions and anatomic variations that made catheter placement difficult. Fluoroscopic and radiographic monitoring not only assisted the performance of endoscopic sphincterotomy, but also confirmed successful results and revealed reasons for failure. Radiographic changes in the biliary tract after sphincterotomy, as well as potential complications of sphincterotomy, are discussed and illustrated

  12. Design and Implementation of Dual Axis Solar Tracking system

    OpenAIRE

    Sirigauri N,; Raghav S

    2015-01-01

    Solar energy is a promising technology that can have huge long term benefits. Solar cells convert the solar energy into electrical energy. Solar tracking system is the most suited technology to improve the efficiency and enhance the performance by utilizing maximum solar energy through the solar cell. In hardware development we utilize LDR’s as sensors and two servomotors to direct the position of the solar panel. The software part is implemented on a code written using an Arduino...

  13. Dual Axis Controller for Extreme Environments, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA's Exploration road map contains an expanded portfolio of destinations including asteroids, comets, Phobos and Deimos, Titan, Ganymede, Mars and the Moon. The...

  14. Dual-axis resonance testing of wind turbine blades

    Science.gov (United States)

    Hughes, Scott; Musial, Walter; White, Darris

    2014-01-07

    An apparatus (100) for fatigue testing test articles (104) including wind turbine blades. The apparatus (100) includes a test stand (110) that rigidly supports an end (106) of the test article (104). An actuator assembly (120) is attached to the test article (104) and is adapted for substantially concurrently imparting first and second forcing functions in first and second directions on the test article (104), with the first and second directions being perpendicular to a longitudinal axis. A controller (130) transmits first and second sets of displacement signals (160, 164) to the actuator assembly (120) at two resonant frequencies of the test system (104). The displacement signals (160, 164) initiate the actuator assembly (120) to impart the forcing loads to concurrently oscillate the test article (104) in the first and second directions. With turbine blades, the blades (104) are resonant tested concurrently for fatigue in the flapwise and edgewise directions.

  15. 21 CFR 892.1840 - Radiographic film.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiographic film. 892.1840 Section 892.1840 Food... DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1840 Radiographic film. (a) Identification. Radiographic film is a device that consists of a thin sheet of radiotransparent material coated on one or both...

  16. Anomalous hydrodynamics in two dimensions

    Indian Academy of Sciences (India)

    Abstract. A new approach is presented to discuss two-dimensional hydrodynamics with gauge and gravitational anomalies. Exact constitutive relations for the stress tensor and charge current are obtained. Also, a connection between response parameters and anomaly coefficients is discussed. These are new results which, ...

  17. Topics in fluctuating nonlinear hydrodynamics

    International Nuclear Information System (INIS)

    Milner, S.T.

    1986-01-01

    Models of fluctuating nonlinear hydrodynamics have enjoyed much success in explaining the effect of long-wavelength fluctuations in diverse hydrodynamic systems. This thesis explores two such problems; in both, the body of hydrodynamic assumptions powerfully constrains the predictions of a well-posed theory. The effects of layer fluctuations in smectic-A liquid crystals are first examined. The static theory (introduced by Grinstein and Pelcovits) is reviewed. Ward identities, resulting from the arbitrariness of the layering direction, are derived and exploited. The static results motivate an examination of dynamic fluctuation effects. A new sound-damping experiment is proposed that would probe singular dependence of viscosities on applied stress. A theory of Procaccia and Gitterman that reaction rates of chemically reacting binary mixtures are drastically reduced near their thermodynamic critical points is analyzed. Hydrodynamic arguments and Van Hove theory are applied, concluding that the PG idea is drastically slowed, and spatially varying composition fluctuations are at best slowed down over a narrow range of wavenumbers

  18. Radiation hydrodynamics in the laboratory

    International Nuclear Information System (INIS)

    1985-12-01

    This report contains a collection of five preprints devoted to the subject of laser induced phenomena of radiation hydrodynamics. These preprints cover approximately the contents of the presentations made by the MPQ experimental laser-plasma group at the 17th European Conference on Laser Interaction with Matter (ECLIM), Rome, November 18-22, 1985. (orig.)

  19. Numerical Hydrodynamics in General Relativity

    Directory of Open Access Journals (Sweden)

    Font José A.

    2003-01-01

    Full Text Available The current status of numerical solutions for the equations of ideal general relativistic hydrodynamics is reviewed. With respect to an earlier version of the article, the present update provides additional information on numerical schemes, and extends the discussion of astrophysical simulations in general relativistic hydrodynamics. Different formulations of the equations are presented, with special mention of conservative and hyperbolic formulations well-adapted to advanced numerical methods. A large sample of available numerical schemes is discussed, paying particular attention to solution procedures based on schemes exploiting the characteristic structure of the equations through linearized Riemann solvers. A comprehensive summary of astrophysical simulations in strong gravitational fields is presented. These include gravitational collapse, accretion onto black holes, and hydrodynamical evolutions of neutron stars. The material contained in these sections highlights the numerical challenges of various representative simulations. It also follows, to some extent, the chronological development of the field, concerning advances on the formulation of the gravitational field and hydrodynamic equations and the numerical methodology designed to solve them.

  20. Hydrodynamics of a quark droplet

    DEFF Research Database (Denmark)

    Bjerrum-Bohr, Johan J.; Mishustin, Igor N.; Døssing, Thomas

    2012-01-01

    We present a simple model of a multi-quark droplet evolution based on the hydrodynamical description. This model includes collective expansion of the droplet, effects of the vacuum pressure and surface tension. The hadron emission from the droplet is described following Weisskopf's statistical...

  1. Hydrodynamic instabilities in inertial fusion

    International Nuclear Information System (INIS)

    Hoffman, N.M.

    1994-01-01

    This report discusses topics on hydrodynamics instabilities in inertial confinement: linear analysis of Rayleigh-Taylor instability; ablation-surface instability; bubble rise in late-stage Rayleigh-Taylor instability; and saturation and multimode interactions in intermediate-stage Rayleigh-Taylor instability

  2. Radiographic evaluation of maxillofacial fractures

    International Nuclear Information System (INIS)

    Litwan, M.; Fliegel, C.

    1986-01-01

    The course and configuration of typical maxillofacial fractures (type Le Fort I-III) and lateral maxillary fractures including the zygomatic arch were reconstructed in detail by application of barium paste on a bony skull and radiogrpahs in standard projections were performed and evaluated. It was obvious from the resulting radiographs that for most maxillofacial fractures a half axial or Water's view was most helpful. Lateral views only give additional information when there is a considerable degree of dislocation of fragments. Comparison with a prediatric skull of 8 years of age demonstrated that fractures of the zygomatic arch in this age group cannot be demonstrated by the typical submento-vertical view, but are shown on a Towne projection. The radiographic appearance of important maxillofacial fractures is demonstrated. The necessity of further studies in cases where reconstructive surgery appears necessary is discussed and CT rather then conventional tomography is advocated. (orig.) [de

  3. Pulmonary edema: radiographic differential diagnosis

    International Nuclear Information System (INIS)

    Yoo, Dong Soo; Choi, Young Hi; Kim, Seung Cheol; An, Ji Hyun; Lee, Jee Young; Park, Hee Hong

    1997-01-01

    To evaluate the feasibility of using chest radiography to differentiate between three different etiologies of pulmonary edema. Plain chest radiographs of 77 patients, who were clinically confirmed as having pulmonary edema, were retrospectively reviewed. The patients were classified into three groups : group 1 (cardiogenic edema : n = 35), group 2 (renal pulmonary edema : n = 16) and group 3 (permeability edema : n = 26). We analyzed the radiologic findings of air bronchogram, heart size, peribronchial cuffing, septal line, pleural effusion, vascular pedicle width, pulmonary blood flow distribution and distribution of pulmonary edema. In a search for radiologic findings which would help in the differentiation of these three etiologies, each finding was assessed. Cardiogenic and renal pulmonary edema showed overlapping radiologic findings, except for pulmonary blood flow distribution. In cardiogenic pulmonary edema (n=35), cardiomegaly (n=29), peribronchial cuffing (n=29), inverted pulmonary blood flow distribution (n=21) and basal distribution of edema (n=20) were common. In renal pulmonary edema (n=16), cardiomegaly (n=15), balanced blood flow distribution (n=12), and central (n=9) or basal distribution of edema (n=7) were common. Permeability edema (n=26) showed different findings. Air bronchogram (n=25), normal blood flow distribution (n=14) and peripheral distribution of edema (n=21) were frequent findings, while cardiomegaly (n=7), peribronchial cuffing (n=7) and septal line (n=5) were observed in only a few cases. On plain chest radiograph, permeability edema can be differentiated from cardiogenic or renal pulmonary edema. The radiographic findings which most reliably differentiated these two etiologies were air bronchogram, distribution of pulmonary edema, peribronchial cuffing and heart size. Only blood flow distribution was useful for radiographic differentiation of cardiogenic and renal edema

  4. Occupational health and the radiographer

    International Nuclear Information System (INIS)

    Stronach, T.

    1990-01-01

    This paper identifies some of the occupational health hazards faced by radiographers in the hospital environment. There has been very little work done in this area in the past, and as the subject is so large this paper can do little other than raise some of the issues . The hazards addressed include: radiation, ergonomics, chemical, environmental, biological, occupational injury and accident, stress. 14 refs., 2 figs

  5. Observer POD for radiographic testing

    Energy Technology Data Exchange (ETDEWEB)

    Kanzler, Daniel; Mueller, Christina; Bertovic, Marija [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany); Pitkaenen, Jorma [Posiva Oy, Eurajoki (Finland)

    2013-07-01

    The radiographic testing is an important non-destructive testing method, especially in industrial areas where people could be injured in case of failing of a component. There it is a mighty method to find volumetric defects. As bigger the penetrated length of the defect in the component is, as bigger is the radiographic contrast. The detectability of volumetric defects in its turn is not only depending on the contrast but also on the noise, the defect area and its shape. The currently applied POD approach uses mostly only the contrast and the noise as detection threshold. This does not reflect accurately the results of evaluations by human observers. A new approach is introduced, using the widely applied POD evaluation and additionally a detection threshold depending on the area of the defect. The presentation shows the process of calculating the POD curves with simulated data by the modeling software aRTist and with artificial reference data. This approach was developed within a joint project with the company POSIVA, which is constructing a final depository for high active nuclear fuels in Finland. Radiographic testing is one of the NDT-methods they use to test the electron beam welds of the copper canisters. The copper canisters will be used in the depository as a corrosion barrier within the waste management concept. (Published as a poster session.)

  6. Automating the radiographic NDT process

    International Nuclear Information System (INIS)

    Aman, J.K.

    1986-01-01

    Automation, the removal of the human element in inspection, has not been generally applied to film radiographic NDT. The justication for automating is not only productivity but also reliability of results. Film remains in the automated system of the future because of its extremely high image content, approximately 8 x 10 9 bits per 14 x 17. The equivalent to 2200 computer floppy discs. Parts handling systems and robotics applied for manufacturing and some NDT modalities, should now be applied to film radiographic NDT systems. Automatic film handling can be achieved with the daylight NDT film handling system. Automatic film processing is becoming the standard in industry and can be coupled to the daylight system. Robots offer the opportunity to automate fully the exposure step. Finally, computer aided interpretation appears on the horizon. A unit which laser scans a 14 x 17 (inch) film in 6 - 8 seconds can digitize film information for further manipulation and possible automatic interrogations (computer aided interpretation). The system called FDRS (for Film Digital Radiography System) is moving toward 50 micron (*approx* 16 lines/mm) resolution. This is believed to meet the need of the majority of image content needs. We expect the automated system to appear first in parts (modules) as certain operations are automated. The future will see it all come together in an automated film radiographic NDT system (author) [pt

  7. A Radiographic Study of Odontoma

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyung Ho; Choi, Karp Shik [Dept. of Dental Radiology, College of Dentistry, Kyungpook National University, Daegu (Korea, Republic of)

    1998-02-15

    The purpose of this study was to obtain information on the clinical and radiographic features of the odontomas in the jaws. For this study, the authors examined and analyzed the clinical records and radiographs of 119 patients who had lesion of odontoma diagnosed by clinical and radiographic examinations. The obtained results were as follows: 1. Odontoma occurred the most frequently in the 2nd decade (45.4%) and occurred more frequently in males (60.5%) than in females (39.5%). 2. The most common clinical symptom was the delayed eruption of the teeth (34.2%). 3. The type of lesions was mainly observed as compound odontoma (80.8%), and internal pattern of the complex odontoma was unevenly radiopaque (73.9%). 4. The compound odontoma frequently occurred in anterior portion of the maxilla (57.7%) and mandible (30.9%), and complex odontoma frequently occurred in anterior portion of maxilla (34.8%) and posterior portion of mandible (30.5%). 5. The effects on adjacent teeth were impaction of teeth (71.7%) and prolonged retention of deciduous teeth (31.7%). 6. The impaction of the teeth occurred in anterior portion of maxilla (44.2%) amd mandible (19.2%), but root resorption of the adjacent teeth were not seen. 7. The boundary to adjacent structure was well-defined , the lesions appear as radiopaque mass with radiolucent rim.

  8. Cervical spine motion: radiographic study

    International Nuclear Information System (INIS)

    Morgan, J.P.; Miyabayashi, T.; Choy, S.

    1986-01-01

    Knowledge of the acceptable range of motion of the cervical spine of the dog is used in the radiographic diagnosis of both developmental and degenerative diseases. A series of radiographs of mature Beagle dogs was used to identify motion within sagittal and transverse planes. Positioning of the dog's head and neck was standardized, using a restraining board, and mimicked those thought to be of value in diagnostic radiology. The range of motion was greatest between C2 and C5. Reports of severe disk degeneration in the cervical spine of the Beagle describe the most severely involved disks to be C4 through C7. Thus, a high range of motion between vertebral segments does not seem to be the cause for the severe degenerative disk disease. Dorsoventral slippage between vertebral segments was seen, but was not accurately measured. Wedging of disks was clearly identified. At the atlantoaxio-occipital region, there was a high degree of motion within the sagittal plane at the atlantoaxial and atlanto-occipital joints; the measurement can be a guideline in the radiographic diagnosis of instability due to developmental anomalies in this region. Lateral motion within the transverse plane was detected at the 2 joints; however, motion was minimal, and the measurements seemed to be less accurate because of rotation of the cervical spine. Height of the vertebral canal was consistently noted to be greater at the caudal orifice, giving some warning to the possibility of overdiagnosis in suspected instances of cervical spondylopathy

  9. Final Report. Hydrodynamics by high-energy-density plasma flow and hydrodynamics and radiative hydrodynamics with astrophysical application

    International Nuclear Information System (INIS)

    R Paul Drake

    2004-01-01

    OAK-B135 This is the final report from the project Hydrodynamics by High-Energy-Density Plasma Flow and Hydrodynamics and Radiation Hydrodynamics with Astrophysical Applications. This project supported a group at the University of Michigan in the invention, design, performance, and analysis of experiments using high-energy-density research facilities. The experiments explored compressible nonlinear hydrodynamics, in particular at decelerating interfaces, and the radiation hydrodynamics of strong shock waves. It has application to supernovae, astrophysical jets, shock-cloud interactions, and radiative shock waves

  10. Radiographic appearances in Crohn's disease. I. Accuracy of radiographic methods

    Energy Technology Data Exchange (ETDEWEB)

    Hildell, J; Lindstroem, C; Wenckert, A [Departments of Diagnostic Radiology, Pathology and Surgery, Malmoe Allmaenna Sjukhus, Malmoe, Sweden

    1979-01-01

    Preoperative films of 176 patients operated upon for Crohn's disease were reviewed and compared with microscopic findings in the resected specimens in order to assess the accuracy of the radiographic techniques used. It was found that a diagnosis of the presence and the extent of the disease was often dependent on the demonstration of minor mucosal ulcers and less marked submucosal edema. These lesions were not adequately demonstrated by any of the techniques used for small bowel examination, but were consistently revealed by the double-contrast technique used for examination of the colon.

  11. Analytic solutions of hydrodynamics equations

    International Nuclear Information System (INIS)

    Coggeshall, S.V.

    1991-01-01

    Many similarity solutions have been found for the equations of one-dimensional (1-D) hydrodynamics. These special combinations of variables allow the partial differential equations to be reduced to ordinary differential equations, which must then be solved to determine the physical solutions. Usually, these reduced ordinary differential equations are solved numerically. In some cases it is possible to solve these reduced equations analytically to obtain explicit solutions. In this work a collection of analytic solutions of the 1-D hydrodynamics equations is presented. These can be used for a variety of purposes, including (i) numerical benchmark problems, (ii) as a basis for analytic models, and (iii) to provide insight into more complicated solutions

  12. Assessment of Radiographic Image Quality by Visual Examination of Neutron Radiographs of the Calibration Fuel Pin

    DEFF Research Database (Denmark)

    Domanus, Joseph Czeslaw

    1986-01-01

    Up till now no reliable radiographic image quality standards exist for neutron radiography of nuclear reactor fuel. Under the Euratoro Neutron Radiography Working Group (NRWG) Test Program neutron radiographs were produced at different neutron radiography facilities within the European Community...... of a calibration fuel pin. The radiographs were made by the direct, transfer and tracketch methods using different film recording materials. These neutron radiographs of the calibration fuel pin were used for the assessement of radiographic image quality. This was done by visual examination of the radiographs...

  13. Laser driven hydrodynamic instability experiments

    International Nuclear Information System (INIS)

    Remington, B.A.; Weber, S.V.; Haan, S.W.; Kilkenny, J.D.; Glendinning, S.G.; Wallace, R.J.; Goldstein, W.H.; Wilson, B.G.; Nash, J.K.

    1993-01-01

    An extensive series of experiments has been conducted on the Nova laser to measure hydrodynamic instabilities in planar foils accelerated by x-ray ablation. Single mode experiments allow a measurement of the fundamental growth rates from the linear well into the nonlinear regime. Two-mode foils allow a first direct observation of mode coupling. Surface-finish experiments allow a measurement of the evolution of a broad spectrum of random initial modes

  14. Rapidity correlations test stochastic hydrodynamics

    International Nuclear Information System (INIS)

    Zin, C; Gavin, S; Moschelli, G

    2017-01-01

    We show that measurements of the rapidity dependence of transverse momentum correlations can be used to determine the characteristic time τ π that dictates the rate of isotropization of the stress energy tensor, as well as the shear viscosity ν = η/sT . We formulate methods for computing these correlations using second order dissipative hydrodynamics with noise. Current data are consistent with τ π /ν ∼ 10 but targeted measurements can improve this precision. (paper)

  15. Hydrodynamic simulations of expanding shells

    Czech Academy of Sciences Publication Activity Database

    Wünsch, Richard; Palouš, Jan; Ehlerová, Soňa

    2004-01-01

    Roč. 289, 3-4 (2004), s. 35-36 ISSN 0004-640X. [From observation to self-consistent modelling of the ISM in galaxies. Porto, 03.09.2002-05.09.2002] R&D Projects: GA AV ČR KSK1048102 Keywords : hydrodynamic simulations * ISM * star formation Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 0.597, year: 2004

  16. Hydrodynamic Limit of Multiple SLE

    Science.gov (United States)

    Hotta, Ikkei; Katori, Makoto

    2018-04-01

    Recently del Monaco and Schleißinger addressed an interesting problem whether one can take the limit of multiple Schramm-Loewner evolution (SLE) as the number of slits N goes to infinity. When the N slits grow from points on the real line R in a simultaneous way and go to infinity within the upper half plane H, an ordinary differential equation describing time evolution of the conformal map g_t(z) was derived in the N → ∞ limit, which is coupled with a complex Burgers equation in the inviscid limit. It is well known that the complex Burgers equation governs the hydrodynamic limit of the Dyson model defined on R studied in random matrix theory, and when all particles start from the origin, the solution of this Burgers equation is given by the Stieltjes transformation of the measure which follows a time-dependent version of Wigner's semicircle law. In the present paper, first we study the hydrodynamic limit of the multiple SLE in the case that all slits start from the origin. We show that the time-dependent version of Wigner's semicircle law determines the time evolution of the SLE hull, K_t \\subset H\\cup R, in this hydrodynamic limit. Next we consider the situation such that a half number of the slits start from a>0 and another half of slits start from -a exact solutions, we will discuss the universal long-term behavior of the multiple SLE and its hull K_t in the hydrodynamic limit.

  17. Hydrodynamical model with massless constituents

    International Nuclear Information System (INIS)

    Chiu, C.B.; Wang, K.H.

    1974-01-01

    Within the constituent hydrodynamical model, it is shown that the total number of constituents is conserved, if these constituents are massless and satisfy the Fermi-Dirac distribution. A simple scheme for the transition from the constituent-phase to the hadron-phase is suggested, and the hadron inclusive momentum spectra are presented for this case. This phase transition scheme predicts the average transverse momentum of meson resonances which is compatible with the data. (U.S.)

  18. Black Hole Scrambling from Hydrodynamics.

    Science.gov (United States)

    Grozdanov, Sašo; Schalm, Koenraad; Scopelliti, Vincenzo

    2018-06-08

    We argue that the gravitational shock wave computation used to extract the scrambling rate in strongly coupled quantum theories with a holographic dual is directly related to probing the system's hydrodynamic sound modes. The information recovered from the shock wave can be reconstructed in terms of purely diffusionlike, linearized gravitational waves at the horizon of a single-sided black hole with specific regularity-enforced imaginary values of frequency and momentum. In two-derivative bulk theories, this horizon "diffusion" can be related to late-time momentum diffusion via a simple relation, which ceases to hold in higher-derivative theories. We then show that the same values of imaginary frequency and momentum follow from a dispersion relation of a hydrodynamic sound mode. The frequency, momentum, and group velocity give the holographic Lyapunov exponent and the butterfly velocity. Moreover, at this special point along the sound dispersion relation curve, the residue of the retarded longitudinal stress-energy tensor two-point function vanishes. This establishes a direct link between a hydrodynamic sound mode at an analytically continued, imaginary momentum and the holographic butterfly effect. Furthermore, our results imply that infinitely strongly coupled, large-N_{c} holographic theories exhibit properties similar to classical dilute gases; there, late-time equilibration and early-time scrambling are also controlled by the same dynamics.

  19. Numerical Hydrodynamics in Special Relativity.

    Science.gov (United States)

    Martí, José Maria; Müller, Ewald

    2003-01-01

    This review is concerned with a discussion of numerical methods for the solution of the equations of special relativistic hydrodynamics (SRHD). Particular emphasis is put on a comprehensive review of the application of high-resolution shock-capturing methods in SRHD. Results of a set of demanding test bench simulations obtained with different numerical SRHD methods are compared. Three applications (astrophysical jets, gamma-ray bursts and heavy ion collisions) of relativistic flows are discussed. An evaluation of various SRHD methods is presented, and future developments in SRHD are analyzed involving extension to general relativistic hydrodynamics and relativistic magneto-hydrodynamics. The review further provides FORTRAN programs to compute the exact solution of a 1D relativistic Riemann problem with zero and nonzero tangential velocities, and to simulate 1D relativistic flows in Cartesian Eulerian coordinates using the exact SRHD Riemann solver and PPM reconstruction. Supplementary material is available for this article at 10.12942/lrr-2003-7 and is accessible for authorized users.

  20. Total elbow arthroplasty: a radiographic outcome study

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Xue Susan [University of Washington, Department of Radiology, Box 357115, Seattle, WA (United States); Petscavage-Thomas, Jonelle M. [Penn State Hershey Medical Center, Department of Radiology, Hershey, PA (United States); Ha, Alice S. [University of Washington, Department of Radiology, Box 354755, Seattle, WA (United States)

    2016-06-15

    Total elbow arthroplasty (TEA) is becoming a popular alternative to arthrodesis for patients with end-stage elbow arthrosis and comminuted distal humeral fractures. Prior outcome studies have primarily focused on surgical findings. Our purpose is to determine the radiographic outcome of TEA and to correlate with clinical symptoms such as pain. This is an IRB-approved retrospective review from 2005 to 2015 of all patients with semiconstrained TEA. All available elbow radiographs and clinical data were reviewed. Data analysis included descriptive statistics and Kaplan-Meier survival curves for radiographic and clinical survival. A total of 104 total elbow arthroplasties in 102 patients were reviewed; 75 % were in women and the mean patient age was 63.1 years. Mean radiographic follow-up was 826 days with average of four radiographs per patient. Seventy TEAs (67 %) developed radiographic complications, including heterotopic ossification (48 %), perihardware lucency (27 %), periprosthetic fracture (23 %), hardware subluxation/dislocation (7 %), polyethylene wear (3 %), and hardware fracture/dislodgement (3 %); 56 patients (55 %) developed symptoms of elbow pain or instability and 30 patients (30 %) underwent at least one reoperation. In patients with radiographic complications, 66 % developed elbow pain, compared to 19 % of patients with no radiologic complications (p = 0.001). Of the patients with radiographic complications, 39 % had at least one additional surgery compared to 0 % of patients without radiographic complications (p = 0.056). Radiographic complications are common in patients after total elbow arthroplasty. There is a strong positive association between post-operative radiographic findings and clinical outcome. Knowledge of common postoperative radiographic findings is important for the practicing radiologist. (orig.)

  1. A radiographic analysis of implant component misfit.

    LENUS (Irish Health Repository)

    Sharkey, Seamus

    2011-07-01

    Radiographs are commonly used to assess the fit of implant components, but there is no clear agreement on the amount of misfit that can be detected by this method. This study investigated the effect of gap size and the relative angle at which a radiograph was taken on the detection of component misfit. Different types of implant connections (internal or external) and radiographic modalities (film or digital) were assessed.

  2. Radiation protection - radiographer's role and responsibilities

    International Nuclear Information System (INIS)

    Popli, P.K.

    2002-01-01

    Ever since discovery of x-rays, radiographers has been the prime user of radiation. With the passage of time, the harmful effects of radiation were detected. Some of radiographers, radiologists and public were affected by radiation, but today with enough knowledge of radiation, the prime responsibility of radiation protection lies with the radiographers only. The radiologist and physicist are also associated with radiation protection to some extent

  3. The use and abuse of radiographic grids

    International Nuclear Information System (INIS)

    Brough, P.D.

    1981-01-01

    It is generally accepted that scattered radiation degrades the quality of the radiographic image. When this problem occurs, a radiographic grid may be applied which necessitates an increase in exposure. Investigations are reported in the following areas: reasons for the introduction of a radiographic grid; the ratio between kilovoltage and grid ratio; techniques resulting in higher contrast and resolution at low patient dose and the abuse of grids

  4. Measure by image analysis of industrial radiographs

    International Nuclear Information System (INIS)

    Brillault, B.

    1988-01-01

    A digital radiographic picture processing system for non destructive testing intends to provide the expert with computer tool, to precisely quantify radiographic images. The author describes the main problems, from the image formation to its characterization. She also insists on the necessity to define a precise process in order to automatize the system. Some examples illustrate the efficiency of digital processing for radiographic images [fr

  5. Radiographic features of periapical cysts and granulomas

    OpenAIRE

    Zain, R. B.; Roswati, N.; Ismail, K.

    1989-01-01

    Many studies have been reported on radiographic lesion sizes of periapical lesions. However no studies have been reported on prevalences of subjective radiographic features in these lesions except for the early assumption that a periapical cyst usually exhibit a radiopaque cortex. This study is conducted to evaluate the prevalences of several subjective radiographic features of periapical cysts and granulomas in the hope to identify features that maybe suggestive of either diagnosis. The resu...

  6. Automating the radiographic NDT process

    International Nuclear Information System (INIS)

    Aman, J.K.

    1988-01-01

    Automation, the removal of the human element in inspection has not been generally applied to film radiographic NDT. The justification for automation is not only productivity but also reliability of results. Film remains in the automated system of the future because of its extremely high image content, approximately 3x10 (to the power of nine) bits per 14x17. This is equivalent to 2200 computer floppy disks parts handling systems and robotics applied for manufacturing and some NDT modalities, should now be applied to film radiographic NDT systems. Automatic film handling can be achieved with the daylight NDT film handling system. Automatic film processing is becoming the standard in industry and can be coupled to the daylight system. Robots offer the opportunity to automate fully the exposure step. Finally, a computer aided interpretation appears on the horizon. A unit which laser scans a 14x27 (inch) film in 6-8 seconds can digitize film in information for further manipulation and possible automatic interrogations (computer aided interpretation). The system called FDRS (for film digital radiography system) is moving toward 50 micron (16 lines/mm) resolution. This is believed to meet the need of the majority of image content needs. (Author). 4 refs.; 21 figs

  7. Prognostic radiographic aspects of spondylolisthesis

    International Nuclear Information System (INIS)

    Saraste, H.; Brostroem, L.A.; Aparisi, T.

    1984-01-01

    A series of 202 patients (133 men, 69 women) with lumbar spondylolysis were examined radiographically on two occasions, first at the time of diagnosis and later at a follow-up, after an observation period of 20 years or more. The films frompatients in groups without and with moderate and severe olisthesis were evaluated with respect to variables describing lumbosacral lordosis, wedging of the spondylolytic vertebra, lengths of the transverse processes and iliolumbar ligaments, disk height, progression of slipping, and influence on measured olisthesis of lumbar spine flexion and extension at the radiographic examination. The evaluation was made with special attention to possible signs which could be predictive for the prognosis of vertebral slipping. Progression of slipping did not differ between patients diagnosed as adults or adolescents. Reduction of disk height was correlated to the degree of slipping present at the initial examination and to the progression of olisthesis. Flexion and extension of the lumbar spine did not modify the degree of olisthesis. Data concerning the lengths of the transverse processes and the iliolumbar ligaments, and lumbar lordosis, cannot be used for prognostic purposes. The lumbar index reflecting the degree of wedge deformity of the spondylolytic vertebra was shown to be the only variable of prognostic value for the development of vertebral slipping. (orig.)

  8. Prognostic radiographic aspects of spondylolisthesis

    Energy Technology Data Exchange (ETDEWEB)

    Saraste, H; Brostroem, L A; Aparisi, T

    1984-01-01

    A series of 202 patients (133 men, 69 women) with lumbar spondylolysis were examined radiographically on two occasions, first at the time of diagnosis and later at a follow-up, after an observation period of 20 years or more. The films from patients in groups without and with moderate and severe olisthesis were evaluated with respect to variables describing lumbosacral lordosis, wedging of the spondylolytic vertebra, lengths of the transverse processes and iliolumbar ligaments, disk height, progression of slipping, and influence on measured olisthesis of lumbar spine flexion and extension at the radiographic examination. The evaluation was made with special attention to possible signs which could be predictive for the prognosis of vertebral slipping. Progression of slipping did not differ between patients diagnosed as adults or adolescents. Reduction of disk height was correlated to the degree of slipping present at the initial examination and to the progression of olisthesis. Flexion and extension of the lumbar spine did not modify the degree of olisthesis. Data concerning the lengths of the transverse processes and the iliolumbar ligaments, and lumbar lordosis, cannot be used for prognostic purposes. The lumbar index reflecting the degree of wedge deformity of the spondylolytic vertebra was shown to be the only variable of prognostic value for the development of vertebral slipping.

  9. Computational simulation of radiographic film

    International Nuclear Information System (INIS)

    Goncalves, Elicardo A. de S.; Santos, Marcio H. dos; Anjos, Marcelino J.; Oliveira, Luis F. de

    2013-01-01

    The composition of a radiographic film gives its values of speed, spatial resolution and base density. The technical knowledge allows to predict how a film with a known composition works, and simulate how this film will work with changes in composition and exposure. In this paper, characterization of films composed by different emulsions was realized, in a way to know the characteristic curve, and to study how the format, organization and concentration of silver salt crystals set the radiographic film images.This work aims to increase an existing simulator, where parallel programming was used to simulate X-ray fluorescence processes. The setup of source and X-ray interactions with objects stills the same, and the detector constructed in this work was placed to form images. At first, considering the approach that the film is a square matrix where each element has a specific quantity of silver grains, that each grain fills a specific area, and that each interaction to radiation transforms a salt silver grain in to metallic silver grain (black grain), we have a blackening standard, and it should show how is the behavior of a optic density in a specific area of the film. Each matrix element has a degree of blackening, and it is proportional to the black grains area. (author)

  10. Stepped scanner radiographic imaging system

    International Nuclear Information System (INIS)

    Lapidus, S.N.

    1981-01-01

    The imaging system includes a radiographic camera, a bed for supporting a subject in view of the camera, and a display system. The camera provides X and Y coordinate signals of each radiographic event. The position of the bed relative to the camera is altered sequentially by drive means, between each of a sequence of images provided by the camera. The sequentially occurring images are presented on the display system, each image being positioned on the display in correspondence with the location of the bed relative to the camera. The coordinates of each image point presented on the display is equal to the sum of the respective X and Y coordinate signals from the camera with X and Y coordinate signals provided by a timer which controls the drive means and defines the location of the bed relative to the camera. The camera is electronically decoupled from the display by a gate during movement of the bed relative to the camera from one location to the next location to prevent any smearing effect within the composite image presented on the display. (author)

  11. Digital processing of radiographic images

    Science.gov (United States)

    Bond, A. D.; Ramapriyan, H. K.

    1973-01-01

    Some techniques are presented and the software documentation for the digital enhancement of radiographs. Both image handling and image processing operations are considered. The image handling operations dealt with are: (1) conversion of format of data from packed to unpacked and vice versa; (2) automatic extraction of image data arrays; (3) transposition and 90 deg rotations of large data arrays; (4) translation of data arrays for registration; and (5) reduction of the dimensions of data arrays by integral factors. Both the frequency and the spatial domain approaches are presented for the design and implementation of the image processing operation. It is shown that spatial domain recursive implementation of filters is much faster than nonrecursive implementations using fast fourier transforms (FFT) for the cases of interest in this work. The recursive implementation of a class of matched filters for enhancing image signal to noise ratio is described. Test patterns are used to illustrate the filtering operations. The application of the techniques to radiographic images of metallic structures is demonstrated through several examples.

  12. Gastric tumors on chest radiographs

    International Nuclear Information System (INIS)

    Tamura, Shozo; Kawanami, Takashi; Russell, W.J.

    1978-04-01

    Gastric neoplasms of three patients protruded into their gas-containing fornices and were first visualized on plain chest radiographs. Endoscopy and/or surgery confirmed these to be a polyp, a leiomyoma, and an adenocarcinoma. The polyp, 1.3 cm in diameter, was the smallest of these three, but smaller lesions may be detectable under suitable conditions. Adequate technique and positioning, sufficiently large lesions in the upper portion of the stomach, a central beam tangential to the tumor, sufficient gas in the stomach, and careful scrutiny by the observer are required. Lesions may be more readily visualized during chest radiography when oral sodium bicarbonate is used to distend the stomach. In chest radiography, exposure limited to the lung fields has been advocated for economy and dose reduction. However, too small an exposure field may result in loss of information potentially beneficial to the patient. Using the smaller of two popular film sizes (35 x 43 cm and 35 x 35 cm), the saving in surface and bone marrow doses is negligible, and the saving in gonad dose may be nil over that when shielding is used. The interest of the observer may be absorbed by a concomitant cardiac or pulmonary lesion. Careful scrutiny of the entire radiograph is therefore essential. (author)

  13. Radiographic localization of unerupted mandibular anterior teeth.

    Science.gov (United States)

    Jacobs, S G

    2000-10-01

    The parallax method and the use of 2 radiographs taken at right angles to each other are the 2 methods generally used to accurately localize teeth. For the parallax method, the combination of a rotational panoramic radiograph with an occlusal radiograph is recommended. This combination involves a vertical x-ray tube shift. Three case reports are presented that illustrate: (1) how this combination can accurately localize unerupted mandibular anterior teeth, (2) how a deceptive appearance of the labiolingual position of the unerupted tooth can be produced in an occlusal radiograph, (3) how increasing the vertical angle of the tube for the occlusal radiograph makes the tube shift easier to discern, (4) why occlusal radiographs are preferable to periapical radiographs for tube shifts, and (5) how localization can also be carried out with 2 radiographs at right angles to each other, one of which is an occlusal radiograph taken with the x-ray tube directed along the long axis of the reference tooth.

  14. Radiographic examination for successful dental implant

    International Nuclear Information System (INIS)

    Lee, Sam Sun; Choi, Soon Chul

    2005-01-01

    Recently implant has become an important field in dental clinic. Radiographic examination of pre- and post-operation is essential for successful treatment. Clinicians should have knowledge about the purpose of the radiographic examination, suitable imaging modality for the cases, anatomic landmarks of tooth and jaw bone, advantage and limitation of panoramic radiographic examination for implant, principle and interpretation of cross-sectional imaging, bone mineral density, post-operative radiographic examination. This paper will be helpful to get above information for dentists who want to do dental implant successfully.

  15. Reference Neutron Radiographs of Nuclear Reactor Fuel

    DEFF Research Database (Denmark)

    Domanus, Joseph Czeslaw

    1986-01-01

    Reference neutron radiographs of nuclear reactor fuel were produced by the Euraton Neutron Radiography Working Group and published in 1984 by the Reidel Publishing Company. In this collection a classification is given of the various neutron radiographic findings, that can occur in different parts...... of pelletized, annular and vibro-conpacted nuclear fuel pins. Those parts of the pins are shown where changes of appearance differ from those for the parts as fabricated. Also radiographs of those as fabricated parts are included. The collection contains 158 neutron radiographs, reproduced on photographic paper...

  16. Entropy-limited hydrodynamics: a novel approach to relativistic hydrodynamics

    Science.gov (United States)

    Guercilena, Federico; Radice, David; Rezzolla, Luciano

    2017-07-01

    We present entropy-limited hydrodynamics (ELH): a new approach for the computation of numerical fluxes arising in the discretization of hyperbolic equations in conservation form. ELH is based on the hybridisation of an unfiltered high-order scheme with the first-order Lax-Friedrichs method. The activation of the low-order part of the scheme is driven by a measure of the locally generated entropy inspired by the artificial-viscosity method proposed by Guermond et al. (J. Comput. Phys. 230(11):4248-4267, 2011, doi: 10.1016/j.jcp.2010.11.043). Here, we present ELH in the context of high-order finite-differencing methods and of the equations of general-relativistic hydrodynamics. We study the performance of ELH in a series of classical astrophysical tests in general relativity involving isolated, rotating and nonrotating neutron stars, and including a case of gravitational collapse to black hole. We present a detailed comparison of ELH with the fifth-order monotonicity preserving method MP5 (Suresh and Huynh in J. Comput. Phys. 136(1):83-99, 1997, doi: 10.1006/jcph.1997.5745), one of the most common high-order schemes currently employed in numerical-relativity simulations. We find that ELH achieves comparable and, in many of the cases studied here, better accuracy than more traditional methods at a fraction of the computational cost (up to {˜}50% speedup). Given its accuracy and its simplicity of implementation, ELH is a promising framework for the development of new special- and general-relativistic hydrodynamics codes well adapted for massively parallel supercomputers.

  17. Solitonic Dispersive Hydrodynamics: Theory and Observation

    Science.gov (United States)

    Maiden, Michelle D.; Anderson, Dalton V.; Franco, Nevil A.; El, Gennady A.; Hoefer, Mark A.

    2018-04-01

    Ubiquitous nonlinear waves in dispersive media include localized solitons and extended hydrodynamic states such as dispersive shock waves. Despite their physical prominence and the development of thorough theoretical and experimental investigations of each separately, experiments and a unified theory of solitons and dispersive hydrodynamics are lacking. Here, a general soliton-mean field theory is introduced and used to describe the propagation of solitons in macroscopic hydrodynamic flows. Two universal adiabatic invariants of motion are identified that predict trapping or transmission of solitons by hydrodynamic states. The result of solitons incident upon smooth expansion waves or compressive, rapidly oscillating dispersive shock waves is the same, an effect termed hydrodynamic reciprocity. Experiments on viscous fluid conduits quantitatively confirm the soliton-mean field theory with broader implications for nonlinear optics, superfluids, geophysical fluids, and other dispersive hydrodynamic media.

  18. Hydrodynamic interactions in active colloidal crystal microrheology

    OpenAIRE

    Weeber, R; Harting, JDR Jens

    2012-01-01

    In dense colloids it is commonly assumed that hydrodynamic interactions do not play a role. However, a found theoretical quantification is often missing. We present computer simulations that are motivated by experiments where a large colloidal particle is dragged through a colloidal crystal. To qualify the influence of long-ranged hydrodynamics, we model the setup by conventional Langevin dynamics simulations and by an improved scheme with limited hydrodynamic interactions. This scheme signif...

  19. Disruptive Innovation in Numerical Hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Waltz, Jacob I. [Los Alamos National Laboratory

    2012-09-06

    We propose the research and development of a high-fidelity hydrodynamic algorithm for tetrahedral meshes that will lead to a disruptive innovation in the numerical modeling of Laboratory problems. Our proposed innovation has the potential to reduce turnaround time by orders of magnitude relative to Advanced Simulation and Computing (ASC) codes; reduce simulation setup costs by millions of dollars per year; and effectively leverage Graphics Processing Unit (GPU) and future Exascale computing hardware. If successful, this work will lead to a dramatic leap forward in the Laboratory's quest for a predictive simulation capability.

  20. Laser driven hydrodynamic instability experiments

    International Nuclear Information System (INIS)

    Remington, B.A.; Weber, S.V.; Haan, S.W.; Kilkenny, J.D.; Glendinning, S.G.; Wallace, R.J.; Goldstein, W.H.; Wilson, B.G.; Nash, J.K.

    1992-01-01

    We have conducted an extensive series of experiments on the Nova laser to measure hydrodynamic instabilities in planar foils accelerated by x-ray ablation. Single mode experiments allow a measurement of the fundamental growth rates from the linear well into the nonlinear regime; multimode foils allow an assessment of the degree of mode coupling; and surface-finish experiments allow a measurement of the evolution of a broad spectrum of random initial modes. Experimental results and comparisons with theory and simulations are presented

  1. Hydrodynamics of post CHF region

    International Nuclear Information System (INIS)

    Ishii, M.; De Jarlais, G.

    1984-04-01

    Among various two-phase flow regimes, the inverted flow in the post-dryout region is relatively less well understood due to its special heat transfer conditions. The review of existing data indicates further research is needed in the areas of basic hydrodynamics related to liquid core disintegration mechanisms, slug and droplet formations, entrainment, and droplet size distributions. In view of this, the inverted flow is studied in detail both analytically and experimentally. Criteria for initial flow regimes in the post-dryout region are given. Preliminary models for subsequent flow regime transition criteria are derived together with correlations for a mean droplet diameter based on the adiabatic simulation data

  2. Problems in astrophysical radiation hydrodynamics

    International Nuclear Information System (INIS)

    Castor, J.I.

    1983-01-01

    The basic equations of radiation hydrodynamics are discussed in the regime that the radiation is dynamically as well as thermally important. Particular attention is paid to the question of what constitutes an acceptable approximate non-relativistic system of dynamical equations for matter and radiation in this regime. Further discussion is devoted to two classes of application of these ideas. The first class consists of problems dominated by line radiation, which is sensitive to the velocity field through the Doppler effect. The second class is of problems in which the advection of radiation by moving matter dominates radiation diffusion

  3. Visual perception and radiographic interpretation

    International Nuclear Information System (INIS)

    Papageorges, M.

    1998-01-01

    Although interpretation errors are common in radiology, their causes are still debated. Perceptual mechanisms appear to be responsible for a large proportion of mistakes made by both neophytes and trained radiologists. Erroneous perception of familiar contours can be triggered by unrelated opacities. Conversely, visual information cannot induce a specific perception if the observer is not familiar with the concept represented or its radiographicappearance. Additionally, the area of acute vision is smaller than is commonly recognized. Other factors, such as the attitude, beliefs,.: preconceptions, and expectations of the viewer, can affect what he or she ''sees'' whenviewing any object, including a radiograph. Familiarity with perceptual mechanisms and the limitations of the visual system as well as multiple readings may be necessary to reduce interpretation errors

  4. Picture chamber for radiographic system

    International Nuclear Information System (INIS)

    1977-01-01

    The picture chamber for a radiographic system is characterised by a base, a first electrode carried in the base, an X-ray irradiation window provided with an outer plate and an inner plate and a conducting surface which serves as a second electrode, which has a plate gripping it at each adjacent edge and which has at the sides a space which is occupied by a filling material, maintained at a steady pressure, by means of the mounting against the base and wherein the inner plate lies against the first electrode and which is provided with a split, and with means for the separation of the split in the area of the inner plate so that a fluid may be retained in the split. (G.C.)

  5. Radiographic techniques for digital mammography

    International Nuclear Information System (INIS)

    Horita, Katsuhei

    2007-01-01

    Since the differences in X-ray absorption between various breast tissues are small, a dedicated X-ray system for examination of the breast and a high-contrast, high-resolution screen/film system (SFM) (light-receiving system) are employed for X-ray diagnosis. Currently, however, there is a strong trend toward digital imaging in the field of general radiography, and this trend is also reflected in the field of mammographic examination. In fact, approximately 70% of facilities purchasing new mammography systems are now selecting a digital mammography system (DRM). Given this situation, this report reviews the differences between SFM and DRM and discusses the radiographic techniques and quality assurance procedures for digital mammography. (author)

  6. Gout: radiographic findings mimicking infection

    International Nuclear Information System (INIS)

    Rousseau, I.; Raymond-Tremblay, D.; Cardinal, E.; Beauregard, C.G.; Braunstein, E.M.; Saint-Pierre, A.

    2001-01-01

    Objective: To describe radiographic features of gout that may mimic infection. Design and patients: We report five patients with acute bacterial gout who presented with clinical as well as radiological findings mimicking acute bacterial septic arthritis or osteomyelitis. Three patients had delay in the appropriate treatment with the final diagnosis being established after needle aspiration and identification of urate crystals under polarized light microscopy. Two patients underwent digit amputation for not responding to antibiotic treatment and had histological findings confirming the diagnosis of gout. Conclusion: It is important for the radiologist to be aware of the radiological manifestations of acute gout that can resemble infection in order to avoid inappropriate diagnosis and delay in adequate treatment. The definitive diagnosis should rely on needle aspiration and a specific search for urate crystals. (orig.)

  7. Radiographic study of the odontoma

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Hyung Kyu [Department of Oral Radiology, College of Dentistry, Seoul National University, Seoul (Korea, Republic of)

    1983-11-15

    The author studied clinically and radiologically 55 cases which had been diagnosed as odontoma in SNUDH. The obtained results were as follows: 1. In sex distribution, there was no prevalence in both sexes. And the incidence was the highest in the 2nd decade (16 patient, 29%). 2. There were 42 cases of compound odontoma (76%) and 13 cases of complex odontoma (24%). In most cases, compound odontoma was located at the anterior portion (34 cases, 81%) and complex odontoma at the posterior portions (9 cases, 69%). 3. There was no apparent clinical symptom in compound odontoma (83%), but in complex odontoma, 80% of cases show swelling. 4. The adjacent root resorption was not observed in any case. 5. Five cases radiographically diagnosed as cystic odontoma were not confirmed histopathologically.

  8. Radiographic inspection on offshore platforms

    International Nuclear Information System (INIS)

    Soares, Sergio Damasceno; Sperandio, Augusto Gasparoni

    1994-01-01

    One of the great challenges for non-destructive inspection is on offshore platforms, where safety is a critical issue. Inspection by gammagraphy is practically forbidden on the platform deck due to problems to personnel safety and radiological protection. Ir-192 sources are used and the risk of an accident with loss of radioisotope must be considered. It is unfeasible to use gammagraphy, because in case of an accident the rapid evacuation from the platform would be impossible. This problem does not occur when X-ray equipment is used as the radiation source. The limited practicality and portability of the X-ray equipment have prevented its use as a replacement for the gammagraphy. This paper presents the preliminary tests to see the viable use of radiographic tests with constant potential on offshore platforms. (author). 2 refs., 1 fig., 2 tabs, 3 photos

  9. Radiographic evaluation of hallux valgus

    International Nuclear Information System (INIS)

    Richardson, M.L.; Hansen, S.T.; Kilcoyne, R.F.

    1987-01-01

    This paper presents the common preoperative and postoperative findings in hallux valgus, a common foot disorder of multiple etiologies, which can lead to significant foot pain and deformity. Little has been published in radiologic literature about the proper initial radiographic workup and the postoperative follow-up of this very common and very treatable cause of foot pain. Besides the primary findings of varus angulation of the first metatarsal and valgus angulation of the great toe, one may also see dorsal slaying of the first metatarsal head. As increased weight is borne by the central metatarsals, they may develop hyperostosis and stress fractures. Angular deformities of the hallux sesamoid joint and lesser toes may also be seen

  10. Hydrodynamics and stellar winds an introduction

    CERN Document Server

    Maciel, Walter J

    2014-01-01

    Stellar winds are a common phenomenon in the life of stars, from the dwarfs like the Sun to the red giants and hot supergiants, constituting one of the basic aspects of modern astrophysics. Stellar winds are a hydrodynamic phenomenon in which circumstellar gases expand towards the interstellar medium. This book presents an elementary introduction to the fundamentals of hydrodynamics with an application to the study of stellar winds. The principles of hydrodynamics have many other applications, so that the book can be used as an introduction to hydrodynamics for students of physics, astrophysics and other related areas.

  11. Hydrodynamic interactions in active colloidal crystal microrheology.

    Science.gov (United States)

    Weeber, R; Harting, J

    2012-11-01

    In dense colloids it is commonly assumed that hydrodynamic interactions do not play a role. However, a found theoretical quantification is often missing. We present computer simulations that are motivated by experiments where a large colloidal particle is dragged through a colloidal crystal. To qualify the influence of long-ranged hydrodynamics, we model the setup by conventional Langevin dynamics simulations and by an improved scheme with limited hydrodynamic interactions. This scheme significantly improves our results and allows to show that hydrodynamics strongly impacts the development of defects, the crystal regeneration, as well as the jamming behavior.

  12. Glass Foreign Body Hand Radiograph

    Directory of Open Access Journals (Sweden)

    Hamid Ehsani-Nia, DO

    2018-04-01

    Full Text Available History of present illness: A 27-year-old female sustained an injury to her left hand after she tripped and fell on a vase. She presented to the emergency department (ED complaining of pain over the laceration. Upon examination, patient presented with multiple small abrasions of the medial aspect of the left 5thdigit that are minimally tender. Additionally, she has one 0.5cm linear laceration of the medial aspect of the 5thmetacarpal with severe tenderness in the area and palpable underlying foreign body. Significant findings: Left hand plain radiography demonstrated a subcutaneous foreign body medial to the 5thmetacarpal that is radiopaque, trapezoidal in shape, and measures approximately 11mm x 3mm. Discussion: Laceration repairs are amongst the most common procedures in the emergency department; however, consideration for foreign body is often underdiagnosed. Imaging is performed in only about 11% of all traumatic wounds in the ED.1 Of those injuries relating to the hand that are subsequently imaged, about 15% are found to have a foreign body.2,3 Additionally, it is estimated that foreign bodies are present in 7% to 8.7% of all wounds caused by glass objects.4,5 Glass is among the most common foreign bodies in lacerations, and fortunately they are radiopaque and relatively well visualized radiographically. It has been demonstrated that 2mm glass foreign bodies have a 99% detection rate with radiography, and 1mm glass foreign bodies an 83% detection rate.6 Patient perception of foreign body has a positive predictive value of 31%, making it a poor source in influencing clinical decision-making to obtain wound radiographs.3 Clinicians should have a high suspicion for foreign body in lacerations, particularly those caused by glass, and utilize close physical examination and imaging for evaluation. Topics: Radiography, glass, foreign body, trauma

  13. Conversion into numerical form of radiographic images

    International Nuclear Information System (INIS)

    Cappabianca, C.; Della Rocca, A.B.; Ferriani, S.

    1986-01-01

    Radiographic means are widely used for non destructive testing. However, human and technological factors strongly influence reliability of the results and further use of these technique. Image Processing can help to overtake those difficulties if radiographic films are previously digitized. This paper shows methods and equipments used in this field. The system EDI (Enea Digital. Imagery) operating in Casaccia Energy Research Centre is described

  14. Dental Radiographs Ordered by Dental Professionals: an ...

    African Journals Online (AJOL)

    Conclusions: Even in resource limited settings dental caries is still the regular indication for taking dental radiographs, and periapical views are the most frequent type of radiograph ordered. Maxillary central incisors and mandibular molars were types of teeth commonly x-rayed mainly due to the aesthetic importance of the ...

  15. Digital interactive learning of oral radiographic anatomy.

    Science.gov (United States)

    Vuchkova, J; Maybury, T; Farah, C S

    2012-02-01

    Studies reporting high number of diagnostic errors made from radiographs suggest the need to improve the learning of radiographic interpretation in the dental curriculum. Given studies that show student preference for computer-assisted or digital technologies, the purpose of this study was to develop an interactive digital tool and to determine whether it was more successful than a conventional radiology textbook in assisting dental students with the learning of radiographic anatomy. Eighty-eight dental students underwent a learning phase of radiographic anatomy using an interactive digital tool alongside a conventional radiology textbook. The success of the digital tool, when compared to the textbook, was assessed by quantitative means using a radiographic interpretation test and by qualitative means using a structured Likert scale survey, asking students to evaluate their own learning outcomes from the digital tool. Student evaluations of the digital tool showed that almost all participants (95%) indicated that the tool positively enhanced their learning of radiographic anatomy and interpretation. The success of the digital tool in assisting the learning of radiographic interpretation is discussed in the broader context of learning and teaching curricula, and preference (by students) for the use of this digital form when compared to the conventional literate form of the textbook. Whilst traditional textbooks are still valued in the dental curriculum, it is evident that the preference for computer-assisted learning of oral radiographic anatomy enhances the learning experience by enabling students to interact and better engage with the course material. © 2011 John Wiley & Sons A/S.

  16. Consultant breast radiographers: Where are we now?

    International Nuclear Information System (INIS)

    Rees, Zebby

    2014-01-01

    Introduction: The aim of this study is to: • Evaluate the current role of the consultant breast radiographer. • Compare current practice with the four key components for consultant practice. • Gauge the support of radiologist colleagues. • Determine the other professional commitments involved with the role. This study could be the precursor for a macro study of all consultant radiographer practice in other specialities. Methodology: Methodology used was a comparative ethnographic study. Questionnaires to the 24 consultant breast radiographers currently in post, and consultant breast radiologists, who work with them, were conducted. Data collection was a qualitative thematic approach. Conclusion: Consultant breast radiographers provide high quality care to patients through excellent clinical practice, leadership and good communication. However, this study shows hospital Trusts emphasis for non medical consultants is for clinical practice first. Some radiologists are still a barrier to progression for consultant breast radiographers, and radiologists have a big influence in recruitment decisions. Consultant breast radiographer posts are well established, their numbers are increasing through recognition of the role and of their abilities and performance. Consultant breast radiographers state that becoming a consultant is the major achievement of their career, proving the Society of Radiographers' vision of the four-tier career structure has been well received by the radiography profession

  17. Equipment for fully automatic radiographic pipe inspection

    International Nuclear Information System (INIS)

    Basler, G.; Sperl, H.; Weinschenk, K.

    1977-01-01

    The patent describes a device for fully automatic radiographic testing of large pipes with longitudinal welds. Furthermore the invention enables automatic marking of films in radiographic inspection with regard to a ticketing of the test piece and of that part of it where testing took place. (RW) [de

  18. Radiographic arthrosis after elbow trauma: interobserver reliability.

    NARCIS (Netherlands)

    Lindenhovius, A.; Karanicolas, P.J.; Bhandari, M.; Ring, D.; Kampen, A. van; et al.,

    2012-01-01

    PURPOSE: This study measured observer variation in radiographic rating of elbow arthrosis. METHODS: Thirty-seven independent orthopedic surgeons graded the extent of elbow arthrosis in 20 consecutive sets of plain radiographs, according to the Broberg and Morrey rating system (grade 0, normal joint;

  19. Automatic Cobb Angle Determination From Radiographic Images

    NARCIS (Netherlands)

    Sardjono, Tri Arief; Wilkinson, Michael H. F.; Veldhuizen, Albert G.; van Ooijen, Peter M. A.; Purnama, Ketut E.; Verkerke, Gijsbertus J.

    2013-01-01

    Study Design. Automatic measurement of Cobb angle in patients with scoliosis. Objective. To test the accuracy of an automatic Cobb angle determination method from frontal radiographical images. Summary of Background Data. Thirty-six frontal radiographical images of patients with scoliosis. Methods.

  20. Influence of radiographic contrast media on phagocytosis

    International Nuclear Information System (INIS)

    Rasmussen, F.; Georgsen, J.; Grunnet, N.; Aalborg Sygehus

    1988-01-01

    To evaluate the influence of radiographic contrast media (CM) on human polymorphonuclear leucocytes (PML), the ability of these cells to ingest latex particles after in vitro exposure to five different radiographic contrast media was investigated. All CM inhibited the phagocytic properties of PML. The inhibition was dose dependent. The inhibitory effect was partly due to hyperosmolality but CM specific inhibition was also evident. (orig.)

  1. Chest Radiographic Findings in Newly Diagnosed Pulmonary ...

    African Journals Online (AJOL)

    Five hundred newly diagnosed cases of Pulmonary Tuberculosis were treated with directly observed short-course treatment and 100 of them had chest radiographic examination done. The various chest radiographic patterns in the 100 subjects were studied and included: Fluffy exudative changes 80(80%), fibrosis 70(70%) ...

  2. Radiographic Arthrosis After Elbow Trauma: Interobserver Reliability

    NARCIS (Netherlands)

    Lindenhovius, Anneluuk; Karanicolas, Paul Jack; Bhandari, Mohit; Ring, David; Allan, Cristopher; Axelrod, Terry; Baratz, Mark; Beingessner, Daphne; Cassidy, Charles; Coles, Chad; Conflitti, Joe; Rocca, Gregory Della; van Dijk, C. Niek; Elmans, L. H. G. J.; Feibe, Roger; Frihagen, Frede; Gosens, Taco; Greenberg, Jeffrey; Grosso, Elena; Harness, Neil; van der Heide, Huub; Jeray, Kyle; Kalainov, David; van Kampen, Albert; Kawamura, Sumito; Kloen, Peter; McCormac, Bob; McKee, Michael; Page, Richard; Pesantez, Rodrigo; Peters, Anil; Petrisor, Brad; Poolman, Rudolf; Richardson, Martin; Seiler, John; Swiontkowski, Marc; Trumble, Thomas; Wright, Thomas; Zalavras, Charalampos; Zura, Robert

    2012-01-01

    Purpose This study measured observer variation in radiographic rating of elbow arthrosis. Methods Thirty-seven independent orthopedic surgeons graded the extent of elbow arthrosis in 20 consecutive sets of plain radiographs, according to the Broberg and Morrey rating system (grade 0, normal joint;

  3. Validity of radiographic assessment of ankylosis

    International Nuclear Information System (INIS)

    Stenvik, A.; Beyer-Olsen, E.; Aabyholm, F.; Haanaes, H.R.; Gerner, N.W.

    1990-01-01

    The accuracy and sensitivity of radiographic assessments of reactive processes in dental tissues were evaluated by comparison of radiographs and histologic sections. Experimental lesions inflicted on the roots of 10 monkey incisors had been observed by means of serially obtained radiographs over a period of 315 to 370 days. The material was used for evaluation of radiographic assessment of ankylosis. For comparative purposes, assessment of the experimental lesion penetrating to the pulp and periapical radiolucency was added. True and falsely positive or negative recordings formed the basis for calculation of the accuracy and sensitivity of the radiographic assessment. The sensitivity, or the obsevers ability to detect the actual changes, was high for pulp penetration, intermediate for inflammation, and low for ankylosis. 6 refs., 3 figs., 2 tabs

  4. Consultant radiographers: Profile of the first generation

    International Nuclear Information System (INIS)

    Forsyth, Lesley J.; Maehle, Valerie

    2010-01-01

    Aim: The aim of this research is to examine the profile of first generation consultant radiographers: their demographics, educational backgrounds, qualifications and training, career experience and progression, teaching, lecturing and research activities. Method: Participant recruitment was drawn from the Society and College of Radiographers consultant radiographer group. Data collection involved a self-administered paper based and web based questionnaire. Results: Participant response rate of 55% (n = 11). Conclusions: The profile of the first consultant radiographer cohort reflects a diverse and eclectic mix. While some aspects of their development such as educational background, clinical training and skills enhancement are comparable to nurse consultants, clinical experience and employment history show some differences. Commitment to development of expert clinical skills is evident within the profile of the first generation cohort of consultant radiographers however research and leadership training are not strong features.

  5. Consultant radiographers: Profile of the first generation

    Energy Technology Data Exchange (ETDEWEB)

    Forsyth, Lesley J., E-mail: l.forsyth@rgu.ac.u [School of Health Sciences, Robert Gordon University, Aberdeen, AB10 7QG (United Kingdom); Maehle, Valerie [Faculty of Health and Social Care, Robert Gordon University, Aberdeen, AB10 7QG (United Kingdom)

    2010-11-15

    Aim: The aim of this research is to examine the profile of first generation consultant radiographers: their demographics, educational backgrounds, qualifications and training, career experience and progression, teaching, lecturing and research activities. Method: Participant recruitment was drawn from the Society and College of Radiographers consultant radiographer group. Data collection involved a self-administered paper based and web based questionnaire. Results: Participant response rate of 55% (n = 11). Conclusions: The profile of the first consultant radiographer cohort reflects a diverse and eclectic mix. While some aspects of their development such as educational background, clinical training and skills enhancement are comparable to nurse consultants, clinical experience and employment history show some differences. Commitment to development of expert clinical skills is evident within the profile of the first generation cohort of consultant radiographers however research and leadership training are not strong features.

  6. Chest radiographic findings in acute paraquat poisoning

    Energy Technology Data Exchange (ETDEWEB)

    Na, Gyeong Gyun; Lee, Mi Sook; Kim, Hee Jun; Sun, In O [Presbyterian Medical Center, Jeonju (Korea, Republic of)

    2016-01-15

    To describe the chest radiographic findings of acute paraquat poisoning. 691 patients visited the emergency department of our hospital between January 2006 and October 2012 for paraquat poisoning. Of these 691, we identified 56 patients whose initial chest radiographs were normal but who developed radiographic abnormalities within one week. We evaluated their radiographic findings and the differences in imaging features based on mortality. The most common finding was diffuse consolidation (29/56, 52%), followed by consolidation with linear and nodular opacities (18/56, 32%), and combined consolidation and pneumomediastinum (7/56, 13%). Pleural effusion was noted in 17 patients (30%). The two survivors (4%) showed peripheral consolidations, while the 54 patients (96%) who died demonstrated bilateral (42/54, 78%) or unilateral (12/54, 22%) diffuse consolidations. Rapidly progressing diffuse pulmonary consolidation was observed within one week on follow-up radiographs after paraquat ingestion in the deceased, but the survivors demonstrated peripheral consolidation.

  7. Invariant description of solutions of hydrodynamic-type systems in hodograph space: hydrodynamic surfaces

    International Nuclear Information System (INIS)

    Ferapontov, E.V.

    2002-01-01

    Hydrodynamic surfaces are solutions of hydrodynamic-type systems viewed as non-parametrized submanifolds of the hodograph space. We propose an invariant differential-geometric characterization of hydrodynamic surfaces by expressing the curvature form of the characteristic web in terms of the reciprocal invariants. (author)

  8. An introduction to relativistic hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Font, Jose A [Departamento de AstronomIa y AstrofIsica, Universidad de Valencia, Dr. Moliner 50, 46100 Burjassot (Valencia) (Spain)

    2007-11-15

    We review formulations of the equations of (inviscid) general relativistic hydrodynamics and (ideal) magnetohydrodynamics, along with methods for their numerical solution. Both systems can be cast as first-order, hyperbolic systems of conservation laws, following the explicit choice of an Eulerian observer and suitable fluid and magnetic field variables. During the last fifteen years, the so-called (upwind) high-resolution shock-capturing schemes based on Riemann solvers have been successfully extended from classical to relativistic fluid dynamics, both special and general. Nowadays, general relativistic hydrodynamical simulations in relativistic astrophysics are routinely performed, particularly within the test-fluid approximation but also for dynamical spacetimes. While such advances also hold true in the case of the MHD equations, the astrophysical applications investigated so far are still limited, yet the field is bound to witness major developments in the near future. The article also presents a brief overview of numerical techniques, providing state-of-the-art examples of their applicability to general relativistic fluids and magneto-fluids in characteristic scenarios of relativistic astrophysics.

  9. Inducer Hydrodynamic Load Measurement Devices

    Science.gov (United States)

    Skelley, Stephen E.; Zoladz, Thomas F.

    2002-01-01

    Marshall Space Flight Center (MSFC) has demonstrated two measurement devices for sensing and resolving the hydrodynamic loads on fluid machinery. The first - a derivative of the six component wind tunnel balance - senses the forces and moments on the rotating device through a weakened shaft section instrumented with a series of strain gauges. This "rotating balance" was designed to directly measure the steady and unsteady hydrodynamic loads on an inducer, thereby defining both the amplitude and frequency content associated with operating in various cavitation modes. The second device - a high frequency response pressure transducer surface mounted on a rotating component - was merely an extension of existing technology for application in water. MSFC has recently completed experimental evaluations of both the rotating balance and surface-mount transducers in a water test loop. The measurement bandwidth of the rotating balance was severely limited by the relative flexibility of the device itself, resulting in an unexpectedly low structural bending mode and invalidating the higher frequency response data. Despite these limitations, measurements confirmed that the integrated loads on the four-bladed inducer respond to both cavitation intensity and cavitation phenomena. Likewise, the surface-mount pressure transducers were subjected to a range of temperatures and flow conditions in a non-rotating environment to record bias shifts and transfer functions between the transducers and a reference device. The pressure transducer static performance was within manufacturer's specifications and dynamic response accurately followed that of the reference.

  10. CHASM Challenge Problem: Lagrangian Hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Hornung, R [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Keasler, J [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gokhale, M [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2010-09-10

    Computer simulations of many science and engineering problems require modeling the equations of hydrodynamics which describe the motion of materials relative to each other induced by various forces. Many important DoD simulation problems involve complex multi-material systems that undergo large deformations. Examples include the analysis of armor defense, penetration mechanics, blast effects, structural integrity, and conventional munitions such as shaped charges and explosively formed projectiles. Indeed, the original motivation for developing codes that solve the equations of hydrodynamics, herein referred to as “hydrocodes”, was to solve problems with defense applications. The FY2010 Requirements Analysis Report issued by the DoD High Performance Computing Modernization Program (HPCMP) Office shows that a major portion of DoD HPC activities involves hydrocodes [HPCMP2010]. The report surveyed 496 projects across the Services and various Agencies, representing 4,050 HPCMP users at more than 125 locations, including government, contractors, and academia, and grouped each project into one of ten categories.

  11. Fluctuating hydrodynamics for ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Lazaridis, Konstantinos [Department of Mathematics and Statistics, Washington State University, Pullman, 99163 (United States); Wickham, Logan [Department of Computer Science, Washington State University, Richland, 99354 (United States); Voulgarakis, Nikolaos, E-mail: n.voulgarakis@wsu.edu [Department of Mathematics and Statistics, Washington State University, Pullman, 99163 (United States)

    2017-04-25

    We present a mean-field fluctuating hydrodynamics (FHD) method for studying the structural and transport properties of ionic liquids in bulk and near electrified surfaces. The free energy of the system consists of two competing terms: (1) a Landau–Lifshitz functional that models the spontaneous separation of the ionic groups, and (2) the standard mean-field electrostatic interaction between the ions in the liquid. The numerical approach used to solve the resulting FHD-Poisson equations is very efficient and models thermal fluctuations with remarkable accuracy. Such density fluctuations are sufficiently strong to excite the experimentally observed spontaneous formation of liquid nano-domains. Statistical analysis of our simulations provides quantitative information about the properties of ionic liquids, such as the mixing quality, stability, and the size of the nano-domains. Our model, thus, can be adequately parameterized by directly comparing our prediction with experimental measurements and all-atom simulations. Conclusively, this work can serve as a practical mathematical tool for testing various theories and designing more efficient mixtures of ionic liquids. - Highlights: • A new fluctuating hydrodynamics method for ionic liquids. • Description of ionic liquid morphology in bulk and near electrified surfaces. • Direct comparison with experimental measurements.

  12. The radiographic acromiohumeral interval is affected by arm and radiographic beam position

    Energy Technology Data Exchange (ETDEWEB)

    Fehringer, Edward V.; Rosipal, Charles E.; Rhodes, David A.; Lauder, Anthony J.; Feschuk, Connie A.; Mormino, Matthew A.; Hartigan, David E. [University of Nebraska Medical Center, Department of Orthopaedic Surgery and Rehabilitation, Omaha, NE (United States); Puumala, Susan E. [Nebraska Medical Center, Department of Preventive and Societal Medicine, Omaha, NE (United States)

    2008-06-15

    The objective was to determine whether arm and radiographic beam positional changes affect the acromiohumeral interval (AHI) in radiographs of healthy shoulders. Controlling for participant's height and position as well as radiographic beam height and angle, from 30 right shoulders of right-handed males without shoulder problems four antero-posterior (AP) radiographic views each were obtained in defined positions. Three independent, blinded physicians measured the AHI to the nearest millimeter in 120 randomized radiographs. Mean differences between measurements were calculated, along with a 95% confidence interval. Controlling for observer effect, there was a significant difference between AHI measurements on different views (p<0.01). All pair-wise differences were statistically significant after adjusting for multiple comparisons (all p values <0.01). Even in healthy shoulders, small changes in arm position and radiographic beam orientation affect the AHI in radiographs. (orig.)

  13. Digital subtraction radiographic evaluation of the standardize periapical intraoral radiographs

    International Nuclear Information System (INIS)

    Cho, Bong Hae; Nah, Kyung Soo

    1993-01-01

    The geometrically standardized intraoral radiographs using 5 occlusal registration material were taken serially from immediate, 1 day, 2, 4, 8, 12 and 16 weeks after making the bite blocks. The qualities of those subtracted images were evaluated to check the degree of reproducibility of each impression material. The results were as follows: 1. The standard deviations of the grey scales of the overall subtracted images were 4.9 for Exaflex, 7.2 for Pattern resin, 9.0 for Tooth Shade Acrylic, 12.2 for XCP only, 14.8 for Impregum. 2. The standard deviation of the grey scales of the overall subtracted images were grossly related to those of the localized horizontal line of interest. 3. Exaflex which showed the best subtracted image quality had 15 cases of straight, 14 cases of wave, 1 case of canyon shape. Impregum which showed the worst subtracted image quality had 4 cases of straight, 8 cases of wave, 18 cases of canyon shape respectively.

  14. Hydrodynamic Overview at Hot Quarks 2016

    International Nuclear Information System (INIS)

    Noronha-Hostler, Jacquelyn

    2017-01-01

    Event-by-event relativistic hydrodynamics has been extremely successful in describing flow observables in heavy-ion collisions. However, the initial state and viscosity simultaneously affect comparisons to data so a discussion of experimental observables that help to distinguish the two follows. Specific problems that arise in the hydrodynamical modeling at the Beam Energy Scan are also addressed. (paper)

  15. Two-fluid hydrodynamic model for semiconductors

    DEFF Research Database (Denmark)

    Maack, Johan Rosenkrantz; Mortensen, N. Asger; Wubs, Martijn

    2018-01-01

    The hydrodynamic Drude model (HDM) has been successful in describing the optical properties of metallic nanostructures, but for semiconductors where several different kinds of charge carriers are present an extended theory is required. We present a two-fluid hydrodynamic model for semiconductors...

  16. Gamma radiographic exposure time indicator

    International Nuclear Information System (INIS)

    Risbud, V.H.; Thiagarajan, A.; Gangadharan, P.

    1979-01-01

    In industrial radiography, with the proper selection of source and film, the radiographic quality depends very much on the exposure time, which in turn depends upon the source strength and the source to film distance. Conventional methods to arrive at correct exposure time involve time consuming calculations and in these methods the knowledge of the above mentioned parameters is imperative. An instrument to determine the required exposure time has been developed which indicates exposure times in about 30 secs. This covers two commonly used gamma radiography sources, viz., 192 Ir and 60 Co and six commonly used radiography films of different speeds. Knowledge of source strength and source to film distance is not required with the use of this instrument. With a knowledge of the total exposure required by the film to give the required sensitivity and by the measurement of radiation level at the film location, the correct exposure time is determined. The radiation level is measured by placing a GM counter behind the radiographic specimen at the film location. To match the responses of the film and the GM counter, the counter is incorporated in a suitably designed probe. In this instruments, an integrator to integrate the GM-pulses and a constant current integrator (timer) are started simultaneously. The voltage at the GM-pulse integrator is compared with a preselected voltage, (selected on the basis of film type, source, source strength and order of object thickness) by a comparator. The comparator is so adjusted that when the GM-pulse integrator voltage exceeds the preselected voltage, it switches its state and stops the integration of constant current. The constant current integrator output which is proportional to the time taken for the GM-pulse integrator to reach the preselected voltage, is read on a meter graduated in terms of exposure time. The instrument can measure exposure times from 5 minutes to 10 hours read in two ranges, the range-changing being automatic

  17. Reporting by radiographers: a policy and practice guide

    International Nuclear Information System (INIS)

    Paterson, Audrey M.; Price, Richard C.; Thomas, Adrian; Nuttall, Lorraine

    2004-01-01

    Reporting by radiographers and other non-medical staff has developed considerably in the past decade, and especially so since the College of Radiographers published its vision paper on reporting by radiographers, in 1997. It was felt necessary, therefore, to develop guidance to assist radiographers and others undertaking radiographic reporting. The guidance provided includes guidance on planning and implementing a reporting service using reporting radiographers; the education, continuing education and support required by reporting radiographers; quality and standards related to reporting; and the nature of a report. Broader issues that will need to be addressed as reporting by radiographers becomes the norm are also raised

  18. Agreement between radiographic and photographic trabecular patterns

    International Nuclear Information System (INIS)

    Korstjens, C.M.; Geraets, W.G.M.; Stelt, P.F. van der; Spruijt, R.J.; Mosekilde, L.

    1998-01-01

    Purpose: It has been hypothesized that photographs can facilitate the interpretation of the radiographic characteristics of trabecular bone. The reliability of these photographic and radiographic approaches has been determined, as have various agreements between the two approaches and their correlations with biomechanical characteristics. Material and Methods: Fourteen vertebral bodies were obtained at autopsy from 6 women and 8 men aged 22-76 years. Photographs (n=28) and radiographs (n=28) were taken of midsagittal slices from the third lumbar vertebra. The radiographs and photographs were digitized and the geometric properties of the trabecular architecture were then determined with a digital images analysis technique. Information on the compressive strength and ash density of the vertebral body was also available. Results: The geometric properties of both radiographs and photographs could be measured with a high degree of reliability (Cronbach's α>0.85). Agreement between the radiographic and photographic approaches was mediocre as only the radiographic measurements showed insignificant correlations (p<0.05) with the biomechanical characteristics. We suggest that optical phenomena may result in the significant correlations between the photographs and the biomechanical characteristics. Conclusion: For digital image processing, radiography offers a superior description of the architecture of trabecular bone to that offered by photography. (orig.)

  19. Agreement between radiographic and photographic trabecular patterns

    Energy Technology Data Exchange (ETDEWEB)

    Korstjens, C.M.; Geraets, W.G.M.; Stelt, P.F. van der [Dept. of Oral Radiology, Academic Centre for Dentistry, Amsterdam (Netherlands); Spruijt, R.J. [Div. of Psychosocial Research and Epidemiology, Netherlands Cancer Inst., Amsterdam (Netherlands); Mosekilde, L. [Dept. of Cell Biology, Univ. of Aarhus (Denmark)

    1998-11-01

    Purpose: It has been hypothesized that photographs can facilitate the interpretation of the radiographic characteristics of trabecular bone. The reliability of these photographic and radiographic approaches has been determined, as have various agreements between the two approaches and their correlations with biomechanical characteristics. Material and Methods: Fourteen vertebral bodies were obtained at autopsy from 6 women and 8 men aged 22-76 years. Photographs (n=28) and radiographs (n=28) were taken of midsagittal slices from the third lumbar vertebra. The radiographs and photographs were digitized and the geometric properties of the trabecular architecture were then determined with a digital images analysis technique. Information on the compressive strength and ash density of the vertebral body was also available. Results: The geometric properties of both radiographs and photographs could be measured with a high degree of reliability (Cronbach`s {alpha}>0.85). Agreement between the radiographic and photographic approaches was mediocre as only the radiographic measurements showed insignificant correlations (p<0.05) with the biomechanical characteristics. We suggest that optical phenomena may result in the significant correlations between the photographs and the biomechanical characteristics. Conclusion: For digital image processing, radiography offers a superior description of the architecture of trabecular bone to that offered by photography. (orig.)

  20. Radiographic markers - A reservoir for bacteria?

    International Nuclear Information System (INIS)

    Tugwell, Jenna; Maddison, Adele

    2011-01-01

    Introduction: Amongst the most frequently handled objects in the radiology department are radiographic markers. They are personal accessories used with every patient, and are kept in the radiographers pockets when not utilised. Upon enquiry it was discovered that many radiographers disregarded the potential of these accessories to become a vector for cross-contamination thus never or rarely clean them. The aims of this study were therefore to identify if radiographic markers are a reservoir for bacteria and to establish an effective cleaning method for decontaminating them. Methodology: 25 radiographers/student radiographers were selected for this study. Swabbing of their markers prior and post cleaning took place. The microbiology laboratory subsequently analyzed the results by quantifying and identifying the bacteria present. The participants also completed a closed questionnaire regarding their markers (e.g. frequency of cleaning and type of marker) to help specify the results gained from the swabbing procedure. Results: From the sample swabbed, 92% were contaminated with various organisms including Staphylococcus and Bacillus species, the amount of bacteria present ranged from 0 to >50 CFU. There were no significant differences between disinfectant wipes and alcohol gel in decontaminating the markers. Both successfully reduced their bacterial load, with 80% of the markers post cleaning having 0 CFU. Conclusion: The results indicated that radiographic markers can become highly contaminated with various organisms thus serve as a reservoir for bacteria. In addition, the markers need to be cleaned on a regular basis, with either disinfectant wipes or alcohol gel to reduce their bacterial load.

  1. Radiographers and trainee radiologists reporting accident radiographs: A comparative plain film-reading performance study

    International Nuclear Information System (INIS)

    Buskov, L.; Abild, A.; Christensen, A.; Holm, O.; Hansen, C.; Christensen, H.

    2013-01-01

    Aim: To compare the diagnostic accuracy and clinical validity of reporting radiographers with that of trainee radiologists whom they have recently joined in reporting emergency room radiographs at Bispebjerg University Hospital. Materials and methods: Plain radiographs of the appendicular skeleton from 1000 consecutive emergency room patients were included in the study: 500 primarily reported by radiographers and 500 by trainee radiologists. The final reporting was subsequently undertaken by a consultant radiologist in consensus with an orthopaedic surgeon. Two observers classified reports as either true positive/negative or false positive/negative based on the final report, which was considered the reference standard. To evaluate the severity of incorrect primary reports, errors were graded into three categories concerning clinical impact and erroneous reports graded as the most severe category were subsequently analysed. Mann–Whitney and Chi-squared tests were used to compare differences and associations between radiographers versus trainee radiologists regarding film reporting. Results: The sensitivity for correct diagnosis was 99% for reporting radiographers and 94% for trainee radiologists. The specificity was found to be 97% for reporting radiographers and 99% for trainee radiologists. Radiographers missed significantly fewer fractures (n = 2) than trainee radiologists (n = 14; p = 0.006) but had a higher, but not significant, degree of overcalling. No significant difference was found between groups regarding clinical impact of incorrect reporting. Conclusion: Trained radiographers report accident radiographs of the extremities with high accuracy and constitute a qualified resource to help meet increasing workload and demands in quality standards.

  2. Hemolytic potential of hydrodynamic cavitation.

    Science.gov (United States)

    Chambers, S D; Bartlett, R H; Ceccio, S L

    2000-08-01

    The purpose of this study was to determine the hemolytic potentials of discrete bubble cavitation and attached cavitation. To generate controlled cavitation events, a venturigeometry hydrodynamic device, called a Cavitation Susceptibility Meter (CSM), was constructed. A comparison between the hemolytic potential of discrete bubble cavitation and attached cavitation was investigated with a single-pass flow apparatus and a recirculating flow apparatus, both utilizing the CSM. An analytical model, based on spherical bubble dynamics, was developed for predicting the hemolysis caused by discrete bubble cavitation. Experimentally, discrete bubble cavitation did not correlate with a measurable increase in plasma-free hemoglobin (PFHb), as predicted by the analytical model. However, attached cavitation did result in significant PFHb generation. The rate of PFHb generation scaled inversely with the Cavitation number at a constant flow rate, suggesting that the size of the attached cavity was the dominant hemolytic factor.

  3. Deterministic hydrodynamics: Taking blood apart

    Science.gov (United States)

    Davis, John A.; Inglis, David W.; Morton, Keith J.; Lawrence, David A.; Huang, Lotien R.; Chou, Stephen Y.; Sturm, James C.; Austin, Robert H.

    2006-10-01

    We show the fractionation of whole blood components and isolation of blood plasma with no dilution by using a continuous-flow deterministic array that separates blood components by their hydrodynamic size, independent of their mass. We use the technology we developed of deterministic arrays which separate white blood cells, red blood cells, and platelets from blood plasma at flow velocities of 1,000 μm/sec and volume rates up to 1 μl/min. We verified by flow cytometry that an array using focused injection removed 100% of the lymphocytes and monocytes from the main red blood cell and platelet stream. Using a second design, we demonstrated the separation of blood plasma from the blood cells (white, red, and platelets) with virtually no dilution of the plasma and no cellular contamination of the plasma. cells | plasma | separation | microfabrication

  4. The hydrodynamic theory of detonation

    Science.gov (United States)

    Langweiler, Heinz

    1939-01-01

    This report derives equations containing only directly measurable constants for the quantities involved in the hydrodynamic theory of detonation. The stable detonation speed, D, is revealed as having the lowest possible value in the case of positive material velocity, by finding the minimum of the Du curve (u denotes the speed of the gases of combustion). A study of the conditions of energy and impulse in freely suspended detonating systems leads to the disclosure of a rarefaction front traveling at a lower speed behind the detonation front; its velocity is computed. The latent energy of the explosive passes into the steadily growing detonation zone - the region between the detonation front and the rarefaction front. The conclusions lead to a new definition of the concept of shattering power. The calculations are based on the behavior of trinitrotoluene.

  5. Fluctuating nonlinear hydrodynamics of flocking

    Science.gov (United States)

    Yadav, Sunil Kumar; Das, Shankar P.

    2018-03-01

    Starting from a microscopic model, the continuum field theoretic description of the dynamics of a system of active ingredients or "particles" is presented. The equations of motion for the respective collective densities of mass and momentum follow exactly from that of a single element in the flock. The single-particle dynamics has noise and anomalous momentum dependence in its frictional terms. The equations for the collective densities are averaged over a local equilibrium distribution to obtain the corresponding coarse grained equations of fluctuating nonlinear hydrodynamics (FNH). The latter are the equations used frequently for describing active systems on the basis of intuitive arguments. The transport coefficients which appear in the macroscopic FNH equations are determined in terms of the parameters of the microscopic dynamics.

  6. Hydrodynamics and phases of flocks

    International Nuclear Information System (INIS)

    Toner, John; Tu Yuhai; Ramaswamy, Sriram

    2005-01-01

    We review the past decade's theoretical and experimental studies of flocking: the collective, coherent motion of large numbers of self-propelled 'particles' (usually, but not always, living organisms). Like equilibrium condensed matter systems, flocks exhibit distinct 'phases' which can be classified by their symmetries. Indeed, the phases that have been theoretically studied to date each have exactly the same symmetry as some equilibrium phase (e.g., ferromagnets, liquid crystals). This analogy with equilibrium phases of matter continues in that all flocks in the same phase, regardless of their constituents, have the same 'hydrodynamic'-that is, long-length scale and long-time behavior, just as, e.g., all equilibrium fluids are described by the Navier-Stokes equations. Flocks are nonetheless very different from equilibrium systems, due to the intrinsically nonequilibrium self-propulsion of the constituent 'organisms'. This difference between flocks and equilibrium systems is most dramatically manifested in the ability of the simplest phase of a flock, in which all the organisms are, on average moving in the same direction (we call this a 'ferromagnetic' flock; we also use the terms 'vector-ordered' and 'polar-ordered' for this situation) to exist even in two dimensions (i.e., creatures moving on a plane), in defiance of the well-known Mermin-Wagner theorem of equilibrium statistical mechanics, which states that a continuous symmetry (in this case, rotation invariance, or the ability of the flock to fly in any direction) can not be spontaneously broken in a two-dimensional system with only short-ranged interactions. The 'nematic' phase of flocks, in which all the creatures move preferentially, or are simply oriented preferentially, along the same axis, but with equal probability of moving in either direction, also differs dramatically from its equilibrium counterpart (in this case, nematic liquid crystals). Specifically, it shows enormous number fluctuations, which

  7. Anomalous hydrodynamics kicks neutron stars

    Energy Technology Data Exchange (ETDEWEB)

    Kaminski, Matthias, E-mail: mski@ua.edu [Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL 35487 (United States); Department of Physics and Astronomy, University of Victoria, Victoria, BC, V8P 5C2 (Canada); Uhlemann, Christoph F. [Department of Physics, University of Washington, Seattle, WA 98195 (United States); Bleicher, Marcus [Frankfurt Institute for Advanced Studies, Goethe-Universität Frankfurt (Germany); Institut für Theoretische Physik, Goethe Universität Frankfurt (Germany); Schaffner-Bielich, Jürgen [Institut für Theoretische Physik, Goethe Universität Frankfurt (Germany)

    2016-09-10

    Observations show that, at the beginning of their existence, neutron stars are accelerated briskly to velocities of up to a thousand kilometers per second. We argue that this remarkable effect can be explained as a manifestation of quantum anomalies on astrophysical scales. To theoretically describe the early stage in the life of neutron stars we use hydrodynamics as a systematic effective-field-theory framework. Within this framework, anomalies of the Standard Model of particle physics as underlying microscopic theory imply the presence of a particular set of transport terms, whose form is completely fixed by theoretical consistency. The resulting chiral transport effects in proto-neutron stars enhance neutrino emission along the internal magnetic field, and the recoil can explain the order of magnitude of the observed kick velocities.

  8. Unicystic Jaw Lesions: A Radiographic Guideline

    Directory of Open Access Journals (Sweden)

    Giju George

    2010-01-01

    Full Text Available The unilocular radiolucencies remain the topic of much interest for the clinicians and histhopathologists for decades. Adequate use of diagnostic aids and careful observation will clinically help the dentist to arrive at a proper diagnosis and renders quality treatment to patients. Despite of the development of various cross-sectional imaging modalities, the radiograph still remains as the first and most important investigation. Jaw bone lesions, especially unilocular ones, are difficult to diagnose radiologically because of their similar radiographic appearance. It is, thus, very important for the clinician to have a sound knowledge of various radiographic features of the tooth and its supporting structures.

  9. A case of a found radiographic source

    International Nuclear Information System (INIS)

    Pucelj, B.; Korun, M.; Kavsek, D.; Kreft, Z.; Krizman, M.; Martincic, R.; Rosman, M.; Sutej, T.

    1996-01-01

    High dose-rate levels were detected outdoors in the vicinity of a bunker used for storage of radiographic sources in a plant which manufactures metallic products. The investigation revealed that radiation was due to a buried sealed radiographic source, containing 28 GBq of 137 Cs. A special republic radiological emergency team removed the source in a carefully planned operation. There was no evidence for overexposure of the population or of radiographic and other workers of the plant. The highest dose to the recovery team was 50 μSv

  10. Hydrodynamic dispersion within porous biofilms

    KAUST Repository

    Davit, Y.

    2013-01-23

    Many microorganisms live within surface-associated consortia, termed biofilms, that can form intricate porous structures interspersed with a network of fluid channels. In such systems, transport phenomena, including flow and advection, regulate various aspects of cell behavior by controlling nutrient supply, evacuation of waste products, and permeation of antimicrobial agents. This study presents multiscale analysis of solute transport in these porous biofilms. We start our analysis with a channel-scale description of mass transport and use the method of volume averaging to derive a set of homogenized equations at the biofilm-scale in the case where the width of the channels is significantly smaller than the thickness of the biofilm. We show that solute transport may be described via two coupled partial differential equations or telegrapher\\'s equations for the averaged concentrations. These models are particularly relevant for chemicals, such as some antimicrobial agents, that penetrate cell clusters very slowly. In most cases, especially for nutrients, solute penetration is faster, and transport can be described via an advection-dispersion equation. In this simpler case, the effective diffusion is characterized by a second-order tensor whose components depend on (1) the topology of the channels\\' network; (2) the solute\\'s diffusion coefficients in the fluid and the cell clusters; (3) hydrodynamic dispersion effects; and (4) an additional dispersion term intrinsic to the two-phase configuration. Although solute transport in biofilms is commonly thought to be diffusion dominated, this analysis shows that hydrodynamic dispersion effects may significantly contribute to transport. © 2013 American Physical Society.

  11. Consultant radiographer leadership - A discussion

    International Nuclear Information System (INIS)

    Hogg, Peter; Hogg, Dianne; Henwood, Suzanne

    2008-01-01

    Effective leadership can be defined in many ways and is an essential element of successful organisations; poor leadership can result in problems such as low staff morale, high staff turnover and reduced productivity. Effective leadership behaviours are well documented in the literature and various leadership models have been proposed that illustrate these behaviours. This discussion paper does not focus on any particular model. Instead it considers the 'Leadership Qualities Framework' which was developed specifically for use within the UK National Health Service. This framework draws upon a range of leadership models and as such it gives a broad indication of leadership behaviours. The framework comprises three components - 'personal qualities', 'setting direction' and 'delivering the service'. This paper commences with an argument as to why effective leadership is important in organisations generally, and specifically within healthcare organisations. Various examples of leadership are illustrated from within and outside the NHS in order to demonstrate effective leadership behaviours. The Leadership Qualities Framework is then examined, along with scenarios to illustrate effective leadership behaviours in context (i.e. within a healthcare organisation). Subsequent reflections on the scenarios aim to identify leadership behaviours that are explained within the framework. The final element of this paper draws on [limited] published evidence of where consultant radiographers have demonstrated effective leadership behaviours. In this section the published evidence is examined and reflected upon. At the end of the article we indicate additional reading for those who wish to further develop their theoretical and practical leadership skills

  12. Radiographic observation for tuberculous spondylitis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chul Se; Jung, Marn Kyoon; Kim, Byung Soo [College of Medicine, Busan National University, Busan (Korea, Republic of)

    1974-04-15

    Radiographic observation of 152 cases of tuberculous spondylitis selected from total 194 cases of tuberculous arthritis during the past 6 years and 8 months, was carried out to study. 1. The youngest one was 15 months old male infant of active tuberculous spondylitis. The active tuberculous spondylitis under 10 years of age were 50 percent (28 cases). 2. The ratio of male to female was 1.5:1 3. The most common site of involvement was the lumbar spine which was 44.1 percent of the total tuberculous spondylitis. The next were thoracic spine (33.6%), and thoraco-lumber spine (13.1%). 4. The most common roentgenographic findings are bony destructions of the vertebral bodies which were 97.4 percent. The next were joint space narrowing (93.4%), osteoporosis (79.6%), kyphosis (34.2%), fusion deformity of the vertebral body (25.7%), and cold abscess shadow (16.4%). 5. The most of patients (88.8%) had or have been pulmonary tuberculous lesions. 6. In annual incidence, the number of patients were not changed greatly.

  13. Radiographic evaluation of AIDS patients

    International Nuclear Information System (INIS)

    Le Blang, S.D.; Witheman, M.L.; Donovan Post, M.J.; Casillas, J.V.

    1995-01-01

    Morphological imaging, based on the use of various techniques including ultrasound, X-ray computed tomography (CT), and magnetic resonance imaging (MRI), plays an important role in the characterization, diagnosis and follow-up of patients with Human Immunodeficiency Virus (HIV) infection and Acquired Immunodeficiency Syndrome (AIDS). While the presence of thoracic infections, the most frequently observed illnesses in AIDS patients, can best be performed by using conventional chest films and CT, the assessment of cerebral involvement in AIDS patients - characterized by the presence of focal masses, demyelination, meningitis, and infarction - is best achieved using MRI. The work-up of patients with gastrointestinal symptoms should include the use of ultrasound for the evaluation of visceral involvement and lymphadenopathy, completed by CT to further characterize pathologic conditions in either the bowel or visceral organs. Ultrasound is the screening exam of choice in AIDS patients with suspected renal disease, but other methods may be necessary for the assessment of the complications due to pharmacological treatment. Musculoskeletal complications may require the combined use of all the above methods, since they may be caused by infections, tumors and rheumatologic illness. The use of the radiographic methods for the detection of the numerous forms of infections and malignancies in AIDS patients is described in detail for the various body districts

  14. Evaluation of underexposed conventional radiographs after digitization

    International Nuclear Information System (INIS)

    Wenz, W.

    1993-01-01

    Inadequate exposure of analogue radiographs is reported in the literature to occur in 5-25% of cases. Therefore, the present study was performed to test whether selective image processing after digitization could reveal diagnostic details on underexposed radiographs. In addition, the minimal exposure values required for diagnostic purposes after adequate image processing were studied. Phantom studies, organ preparations and measurements of physical parameters with decreasing exposure values were performed. The detection of anatomic and pathologic (nondisplaced fracture lines, microcalcification and renal stones) structures were evaluated by 12 readers. Radiographs with exposure values 20-40% lower than 'ideal' values can provide adequate diagnostic images after digital processing. The diagnostic information is significantly impaired with values under 50% of the correct exposure values. In conclusion, this method is adequate to save underexposed radiographs for diagnostic purposes and to avoid repeated examinations. (orig.) [de

  15. Radiographic features of appendiceal colic in children

    International Nuclear Information System (INIS)

    Schisgall, R.M.

    1986-01-01

    The concept of appendiceal colic was introduced in 1980 to explain the common problem of recurrent crampy abdominal pain (RAP) in children. Children with appendiceal colic often have inspissated casts of stool as foreign bodies of the appendix. The radiographic findings of 115 children operated upon for appendiceal colic have been reviewed. The radiographic features of this syndrom have included: filling defects of the appendix (83% incidence of inspissated casts of stool within the appendix); partial filling of the appendix (44% incidence of fecal casts); retained barium behind 72 h (92% incidence of fecal casts blocking egress of barium); non-visualization of the appendix (42% incidence of fecal casts); and distention of the appendix (100% incidence of fecal casts). The correlation of radiographic and operative findings will be presented. A rational approach to the radiographic workup of a child with RAP will be presented. (orig.)

  16. Radiographers and radiologists reporting plain radiograph requests from accident and emergency and general practice

    International Nuclear Information System (INIS)

    Brealey, S.D.; King, D.G.; Hahn, S.; Crowe, M.; Williams, P.; Rutter, P.; Crane, S.

    2005-01-01

    AIM: To assess selectively trained radiographers and consultant radiologists reporting plain radiographs for the Accident and Emergency Department (A and E) and general practitioners (GPs) within a typical hospital setting. METHODS: Two radiographers, a group of eight consultant radiologists, and a reference standard radiologist independently reported under controlled conditions a retrospectively selected, random, stratified sample of 400 A and E and 400 GP plain radiographs. An independent consultant radiologist judged whether the radiographer and radiologist reports agreed with the reference standard report. Clinicians then assessed whether radiographer and radiologist incorrect reports affected confidence in their diagnosis and treatment plans, and patient outcome. RESULTS: For A and E and GP plain radiographs, respectively, there was a 1% (95% confidence interval (CI) -2 to 5) and 4% (95% CI -1 to 8) difference in reporting accuracy between the two professional groups. For both A and E and GP cases there was an 8% difference in the clinicians' confidence in their diagnosis based on radiographer or radiologist incorrect reports. For A and E and GP cases, respectively, there was a 2% and 8% difference in the clinicians' confidence in their management plans based on radiographer or radiologist incorrect reports. For A and E and GP cases, respectively, there was a 1% and 11% difference in effect on patient outcome of radiographer or radiologist incorrect reports. CONCLUSION: There is the potential to extend the reporting role of selectively trained radiographers to include plain radiographs for all A and E and GP patients. Further research conducted during clinical practice at a number of sites is recommended

  17. Radiographic study of the hepatomegaly

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Byung Soo [Busan National University College of Medicine, Pusan (Korea, Republic of)

    1980-06-15

    The author studied, with emphasis on the various radiographic projections, the 99 cases of liver enlargement, which underwent the barium meal upper gastrointestinal examinations for the purpose of pursuit of significance of liver enlargement and, at the same time were confirmed by other clinical and pathological methods at Busan National University Hospital for about 2 years from November 1977 to September 1979. The following results were obtained: 1. The incidence of liver enlargement was 63.3% (62 cases) in the 5th decade, which was most prevalent, 18.2% (18 cases) in the 3rd decade, 15.2% (15 cases) in the group over 60, and 3.0% (3 cases) in the age group below 20. Male to female sex ratio was 2 : 1. 2. The causes of the liver enlargement confirmed by the final diagnosis are as follows: Primary hepatic cancer 39 cases (39.3%), liver cirrhosis 30 cases (30.3%), chronic hepatitis 12 cases (12.1%), cancer of the biliary tract 6 cases (6.1%), hepatic fluke 6 cases (6.1%), metastatic tumors 3 cases (3.0%), and hepatic congestion 3 cases (3.0%) 3. In the prone view, the displacement of the duodenal bulb appeared in 18 cases (18.2%). 4. In the routine radiographs, the displacement of the stomach to the left and the pressure indentation of the lesser curvature were noted in 69 cases (69.7%) out of 99 cases. 5.In the left lateral recumbent view, the pressure indentation of the anterior border of the gastric body was seen in 96 cases (97.0%) among the 99 cases, the straightening in 30 cases (27.3%), the marked depression in 30 cases (30.3%), the moderate in 27 cases (27.3%), the minimal in 9 cases (9.1%). 6. Comparing the incidences of the roentgen findings of the liver enlargement in the various projections respectively, the displacement of the duodenal bulb was noted in 18 cases (18.3%) in the prone position. The erect position revealed the displacement of the stomach to the left and the pressure indentation in 57 cases (57.6%), the prone position in 51 cases (51

  18. Radiation recommendation series: administratively required dental radiographs

    International Nuclear Information System (INIS)

    1981-09-01

    Administrative requirements for radiographs are found in many segments of the United States health care system. This document presents an FDA radiation recommendation on administratively required dental x-ray examinations. In general, such examinations are not requested to further the patient's dental health, but rather as a means of monitoring claims. However, the administrative use of radiographs that have been taken in the normal course of patient care is usually appropriate, as long as the patient's right to privacy is respected

  19. Consultant radiographer leadership - A discussion

    Energy Technology Data Exchange (ETDEWEB)

    Hogg, Peter [Directorate of Radiography, University of Salford, Allerton Building, Frederick Road, Salford, Greater Manchester M6 6PU (United Kingdom)], E-mail: p.hogg@salford.ac.uk; Hogg, Dianne [Henwood Associates (South East) Ltd, Company Number: 513796, Registered Office: 2 Lakeview Stables, Lower St Clere, Kemsing, Kent, TN15 6NL (United Kingdom); Henwood, Suzanne [East Lancashire Primary Care Trust, Linden Business Centre, Linden Road, Colne. BB8 9BA (United Kingdom)

    2008-12-15

    Effective leadership can be defined in many ways and is an essential element of successful organisations; poor leadership can result in problems such as low staff morale, high staff turnover and reduced productivity. Effective leadership behaviours are well documented in the literature and various leadership models have been proposed that illustrate these behaviours. This discussion paper does not focus on any particular model. Instead it considers the 'Leadership Qualities Framework' which was developed specifically for use within the UK National Health Service. This framework draws upon a range of leadership models and as such it gives a broad indication of leadership behaviours. The framework comprises three components - 'personal qualities', 'setting direction' and 'delivering the service'. This paper commences with an argument as to why effective leadership is important in organisations generally, and specifically within healthcare organisations. Various examples of leadership are illustrated from within and outside the NHS in order to demonstrate effective leadership behaviours. The Leadership Qualities Framework is then examined, along with scenarios to illustrate effective leadership behaviours in context (i.e. within a healthcare organisation). Subsequent reflections on the scenarios aim to identify leadership behaviours that are explained within the framework. The final element of this paper draws on [limited] published evidence of where consultant radiographers have demonstrated effective leadership behaviours. In this section the published evidence is examined and reflected upon. At the end of the article we indicate additional reading for those who wish to further develop their theoretical and practical leadership skills.

  20. Early characteristic radiographic changes in mucolipidosis II

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Lillian M. [Lucile Packard Children' s Hospital and Stanford University, Pediatric Radiology, Palo Alto, CA (United States); Lachman, Ralph S. [Lucile Packard Children' s Hospital and Stanford University, Pediatric Radiology, Palo Alto, CA (United States); University of California, International Skeletal Dysplasia Registry, Los Angeles, CA (United States)

    2016-11-15

    Although mucolipidosis type II has similar metabolic abnormalities to those found in all the mucopolysaccharidoses and mucolipidoses, there are distinctive diagnostic radiographic changes of mucolipidosis II in the perinatal/newborn/infant period. To describe the early characteristic radiographic changes of mucolipidosis II and to document when these changes manifest and resolve. We retrospectively reviewed radiographs and clinical records of 19 cases of mucolipidosis II from the International Skeletal Dysplasia Registry (1971-present; fetal age to 21/2 years). A radiologist with special expertise in skeletal dysplasias evaluated the radiographs. The most common abnormalities were increased vertebral body height (80%, nonspecific), talocalcaneal stippling (86%), periosteal cloaking (74%) and vertebral body rounding (50%). Unreported findings included sacrococcygeal sclerosis (54%) and vertebral body sclerosis (13%). Rickets and hyperparathyroidism-like (pseudohyperparathyroidism) changes (rarely reported) were found in 33% of cases. These changes invariably started in the newborn period and resolved by 1 year of age. The conversion from these early infantile radiographic features to dysostosis multiplex changes occurred in 41% of cases, and within the first year after birth. Several findings strongly suggest the diagnosis of mucolipidosis II, including cloaking in combination with one or more of the following radiographic criteria: talocalcaneal stippling, sacrococcygeal or generalized vertebral body sclerosis, vertebral body rounding, or rickets/hyperparathyroidism-like changes in the perinatal/newborn/infancy period. These findings are not found in the other two forms of mucolipidosis nor in any of the mucopolysaccharidoses. (orig.)

  1. Early characteristic radiographic changes in mucolipidosis II

    International Nuclear Information System (INIS)

    Lai, Lillian M.; Lachman, Ralph S.

    2016-01-01

    Although mucolipidosis type II has similar metabolic abnormalities to those found in all the mucopolysaccharidoses and mucolipidoses, there are distinctive diagnostic radiographic changes of mucolipidosis II in the perinatal/newborn/infant period. To describe the early characteristic radiographic changes of mucolipidosis II and to document when these changes manifest and resolve. We retrospectively reviewed radiographs and clinical records of 19 cases of mucolipidosis II from the International Skeletal Dysplasia Registry (1971-present; fetal age to 21/2 years). A radiologist with special expertise in skeletal dysplasias evaluated the radiographs. The most common abnormalities were increased vertebral body height (80%, nonspecific), talocalcaneal stippling (86%), periosteal cloaking (74%) and vertebral body rounding (50%). Unreported findings included sacrococcygeal sclerosis (54%) and vertebral body sclerosis (13%). Rickets and hyperparathyroidism-like (pseudohyperparathyroidism) changes (rarely reported) were found in 33% of cases. These changes invariably started in the newborn period and resolved by 1 year of age. The conversion from these early infantile radiographic features to dysostosis multiplex changes occurred in 41% of cases, and within the first year after birth. Several findings strongly suggest the diagnosis of mucolipidosis II, including cloaking in combination with one or more of the following radiographic criteria: talocalcaneal stippling, sacrococcygeal or generalized vertebral body sclerosis, vertebral body rounding, or rickets/hyperparathyroidism-like changes in the perinatal/newborn/infancy period. These findings are not found in the other two forms of mucolipidosis nor in any of the mucopolysaccharidoses. (orig.)

  2. Radiographic manifestations of arthritis in AIDS patients

    International Nuclear Information System (INIS)

    Rosenberg, Z.S.; Norman, A.; Solomon, G.

    1988-01-01

    The purpose of this study is to familiarize the radiologist with a newly discovered association between arthritis and acquired immunodeficiency syndrome (AIDS). The authors retrospectively reviewed the clinical and radiographic findings in 31 patients with human immunodeficiency virus (HIV) infection referred to their rheumatology clinic with musculoskeletal complaints. The patients carried a wide range of clinical diagnosis including Reiter syndrome, psoriatic arthritis, undifferentiated seronegative arthritis, isolated enthesopathies, rheumatoid arthritis and osteonecrosis. Radiographs were available in 24 of the 31 patients, and in 20 they showed radiographic features of arthritis, which included soft-tissue swelling periarticular osteoporosis, synovial effusions, sacroiliitis, periosteal reaction, joint space narrowing, marginal erosions, and osteonecrosis. Although the radiographic abnormalities were frequently mild, they were significant, given the short duration of disease in many of their patients (weeks to months) at the time radiographs were obtained. The range of radiographic findings in their series was varied and paralleled the wide range of clinical diagnoses. No findings were pathognomonic for HIV-associated arthritis. Nevertheless, HIV infection needs to be considered in any patient belonging to a recognized risk group who presents with musculoskeletal disease. This is particularly important since immunosupressive drugs used for the treatment of arthritis can be detrimental to patients with HIV infection

  3. Radiation protection education and training of radiographers

    International Nuclear Information System (INIS)

    Elsakkers, P.

    1995-01-01

    The International Society of Radiographers and Radiological Technicians (ISRRT) is an international non-governmental organisation in official relationship with the World Health Organization. Over 50 countries are members of the ISRRT. The ISRRT encourages and facilitates communication between radiographers throughout the world. The ISRRT has produced several documents, e.g. ''The Role of the Radiographer in Europe''. The ISRRT has also done research and developed initiatives to analyse the quality of training of radiographers in the different member states of the EC. Research was done in the member states to analyse the efforts in the field of quality control. An extended study was performed on the current level of education in radiation protection in the European member states. The ICRP recommends in its publications the need of good training and continuing education for all radiographers. An important part of the basic training of radiographers should focus on the performance of radiation protection and quality control tests. Good daily practice can decrease patient dose in many ways. (Author)

  4. Radiographic signs and diagnosis of dental disease

    International Nuclear Information System (INIS)

    Bellows, J.

    1993-01-01

    Dental radiographs are critical for the complete assessment and treatment of dental diseases. Dental radiography is commonly used to evaluate congenital dental defects, periodontal disease, orthodontic manipulations, oral tumors, endodontic treatments, oral trauma, and any situation where an abnormality is suspected. Although standard radiographic equipment and film can be used to produce dental radiographs, dental X-ray equipment and film provide superior quality images and greater convenience of animal patient positioning. An understanding of normal dental radiographic anatomy is important when interpreting dental radiographs. Stage III periodontitis is the earliest stage of periodontal disease at which radiographic abnormalities become apparent. Bone loss associated with periodontal disease can be classified as either horizontal or vertical. Periapical radiolucencies can represent granulomas, cysts, or abscesses, whereas periapical radiodensities may represent sclerotic bone or condensing osteitis. Lytic lesions of the bone of the jaw often represent oral neoplasms. Neoplasms also can displace or disrupt teeth in the dental arch. Resorptive lesions can be external or internal and appear as radiolucent areas involving the external surface of the root or the pulp cavity, respectively. Feline dental resorptive lesions, also known as odontoclastic resorptions, are a specific form of dental resorptive lesions unique to cats

  5. A radiographic study of pediatric ulnar anatomy.

    Science.gov (United States)

    Cravino, Mattia; Oni, Julius K; Sala, Debra A; Chu, Alice

    2014-01-01

    The adult ulna has a unique bony architecture that has been described in the literature, but, to the best of our knowledge, the ulnar anatomy in children has not been described. We examined 75 anteroposterior (AP) and 64 lateral radiographs (29 were bilateral) of 50, 0.5- to 11-year-old, healthy children's forearms. On AP radiographs, the total ulnar length, the ulnar proximal angle, the ulnar distal angle, and the distance between each angle from the tip of the triceps insertion; and, on lateral radiographs, the ulnar length and bow deviation were measured. The correlation between age and radiographic measurements, differences based on sex, differences compared with adults' measurements, and interobserver/intraobserver reliability were assessed. Age had a very strong/strong positive correlation with length/distance measurements on both AP and lateral radiographs. Only AP ulnar distal angle was significantly different between sexes (females > males). Compared with the adult ulnar studies, the AP proximal angle in children is significantly smaller and the location of this angle is significantly more distal. Interobserver and intraobserver reliability were very good for length/distance measurements on AP and lateral radiographs. The knowledge of pediatric ulnar anatomy could be helpful in the treatment of forearm deformities due to multiple hereditary exostosis and osteogenesis imperfecta, and in the treatment of ulnar fractures, particularly in Monteggia variants, where restoration of the correct forearm anatomy is essential to obtain good clinical and functional results. Study of diagnostic test, Level II.

  6. Radiographer performed single contrast small bowel enteroclysis

    International Nuclear Information System (INIS)

    Law, Robert L.; Slack, Nicola; Harvey, Richard F.

    2005-01-01

    Aim: To analyse the technical success and reporting sensitivity of radiographer performed small bowel enteroclysis (SBE) undertaken by a specialist radiographer according to a standard technique [Nolan DJ, Cadman PJ. The small bowel enema made easy. Clinical Radiology 1987;38(3):295-301]. Methods: Patients (1413) had 1646 SBE in 10 years from May 1992 to April 2002. The original request card and the separate radiographer and consultant radiologist reports were reviewed. Where the radiology reports were discordant or inconclusive, the clinical notes were also reviewed. Results: Patients (1022) X-ray films were available. Nine hundred and forty-three (93.3%) SBEs had been successfully completed. Radiographer and consultant radiologist reporting had a 99.3% concordance. There was a 98.4% sensitivity for Crohn's disease (181 of 184 cases where Crohn's disease was the clinical final diagnosis). Overall reporting sensitivity was 93.7% although correct 'probably normal and abnormal' reporting bias suggests a sensitivity of 96.9%. Sixty of 943 (6.4%) reports were inconclusive. Of 1022 patients, 68 (6.6%) of small bowel intubations were not achieved, or else consent was withdrawn at the time of the procedure. Conclusion: Specialist radiographers can perform small bowel enteroclysis with a reporting sensitivity equal to that of a consultant radiologist. Radiographers accustomed to providing an SBE service become skilled at passing fine bore feeding tubes into the small bowel and can provide this service also

  7. Relativistic conformal magneto-hydrodynamics from holography

    International Nuclear Information System (INIS)

    Buchbinder, Evgeny I.; Buchel, Alex

    2009-01-01

    We use the AdS/CFT correspondence to study first-order relativistic viscous magneto-hydrodynamics of (2+1)-dimensional conformal magnetic fluids. It is shown that the first order magneto-hydrodynamics constructed following Landau and Lifshitz from the positivity of the entropy production is inconsistent. We propose additional contributions to the entropy motivated dissipative current and, correspondingly, new dissipative transport coefficients. We use the strongly coupled M2-brane plasma in external magnetic field to show that the new magneto-hydrodynamics leads to self-consistent results in the shear and sound wave channels.

  8. Dileptons from transport and hydrodynamical models

    International Nuclear Information System (INIS)

    Huovinen, P.; Koch, V.

    2000-01-01

    Transport and hydrodynamical models used to describe the expansion stage of a heavy-ion collision at the CERN SPS give different dilepton spectrum even if they are tuned to reproduce the observed hadron spectra. To understand the origin of this difference we compare the dilepton emission from transport and hydrodynamical models using similar initial states in both models. We find that the requirement of pion number conservation in a hydrodynamical model does not change the dilepton emission. Also the mass distribution from the transport model indicates faster cooling and longer lifetime of the fireball

  9. Tuning bacterial hydrodynamics with magnetic fields

    Science.gov (United States)

    Pierce, C. J.; Mumper, E.; Brown, E. E.; Brangham, J. T.; Lower, B. H.; Lower, S. K.; Yang, F. Y.; Sooryakumar, R.

    2017-06-01

    Magnetotactic bacteria are a group of motile prokaryotes that synthesize chains of lipid-bound, magnetic nanoparticles called magnetosomes. This study exploits their innate magnetism to investigate previously unexplored facets of bacterial hydrodynamics at surfaces. Through use of weak, uniform, external magnetic fields and local, micromagnetic surface patterns, the relative strength of hydrodynamic, magnetic, and flagellar force components is tuned through magnetic control of the bacteria's orientation. The resulting swimming behaviors provide a means to experimentally determine hydrodynamic parameters and offer a high degree of control over large numbers of living microscopic entities. The implications of this controlled motion for studies of bacterial motility near surfaces and for micro- and nanotechnology are discussed.

  10. Conformal invariance in hydrodynamic turbulence

    International Nuclear Information System (INIS)

    Falkovich, Gregory

    2007-01-01

    This short survey is written by a physicist. It contains neither theorems nor precise definitions. Its main content is a description of the results of numerical solution of the equations of fluid mechanics in the regime of developed turbulence. Due to limitations of computers, the results are not very precise. Despite being neither exact nor rigorous, the findings may nevertheless be of interest for mathematicians. The main result is that the isolines of some scalar fields (vorticity, temperature) in two-dimensional turbulence belong to the class of conformally invariant curves called SLE (Scramm-Loewner evolution) curves. First, this enables one to predict and find a plethora of quantitative relations going far beyond what was known previously about turbulence. Second, it suggests relations between phenomena that seemed unrelated, like the Euler equation and critical percolation. Third, it shows that one is able to get exact analytic results in statistical hydrodynamics. In short, physicists have found something unexpected and hope that mathematicians can help to explain it.

  11. The hydrodynamics of swimming microorganisms

    International Nuclear Information System (INIS)

    Lauga, Eric; Powers, Thomas R

    2009-01-01

    Cell motility in viscous fluids is ubiquitous and affects many biological processes, including reproduction, infection and the marine life ecosystem. Here we review the biophysical and mechanical principles of locomotion at the small scales relevant to cell swimming, tens of micrometers and below. At this scale, inertia is unimportant and the Reynolds number is small. Our emphasis is on the simple physical picture and fundamental flow physics phenomena in this regime. We first give a brief overview of the mechanisms for swimming motility, and of the basic properties of flows at low Reynolds number, paying special attention to aspects most relevant for swimming such as resistance matrices for solid bodies, flow singularities and kinematic requirements for net translation. Then we review classical theoretical work on cell motility, in particular early calculations of swimming kinematics with prescribed stroke and the application of resistive force theory and slender-body theory to flagellar locomotion. After examining the physical means by which flagella are actuated, we outline areas of active research, including hydrodynamic interactions, biological locomotion in complex fluids, the design of small-scale artificial swimmers and the optimization of locomotion strategies.

  12. Pulsed high-energy radiographic machine emitting x-rays: PHERMEX

    International Nuclear Information System (INIS)

    Dick, R.D.

    1976-01-01

    The PHERMEX facility that is used to provide radiography of explosives and explosive-driven systems is described. This facility allows precision flash radiography of large objects containing high atomic number materials. The facility consists of a high-current, three-cavity, 27-MeV linear electron accelerator; a 13.5-MW radiofrequency power source; a timing, firing, and signal detection system; and a data acquisition system. PHERMEX was built in the early part of the 1960s to complement other hydrodynamics facilities at Los Alamos and to implement studies related to shock waves, detonation, and other hydrodynamic phenomena. After 15 y of operation and several thousand explosive shots later, PHERMEX has proven to be a very important diagnostic tool in the study of hydrodynamic systems. The attractive features of PHERMEX are the following: very intense submicrosecond 27-MeV bremsstrahlung radiation; 1-mm diam spot size; 100 R at 1 m from a 200-ns pulse; precise determination of edges, discontinuities, and areal mass distribution; and flash radiographs of large explosive systems close to the target

  13. Framing Camera Improvements and hydrodynamic Experiments

    National Research Council Canada - National Science Library

    Drake, R. P

    2007-01-01

    .... We also propose to participate in hydrodynamic experiments at NRL whenever they occur, to prepare for an experiment for NIKE to study the onset of turbulence via the Kelvin Helmholtz instability...

  14. Hydrodynamic limit of interacting particle systems

    International Nuclear Information System (INIS)

    Landim, C.

    2004-01-01

    We present in these notes two methods to derive the hydrodynamic equation of conservative interacting particle systems. The intention is to present the main ideas in the simplest possible context and refer for details and references. (author)

  15. Radiographic and Clinical Analysis of Lateral Epicondylitis.

    Science.gov (United States)

    Shillito, Matthew; Soong, Maximillian; Martin, Nicholas

    2017-06-01

    The literature suggests that radiographs may be unnecessary in the initial evaluation of lateral epicondylitis because treatment is rarely altered as a result of the radiographic findings. The most commonly reported radiographic finding is calcification at the lateral epicondyle. Our goal was to perform a quantitative and qualitative analysis of this finding to determine its importance and possible relationship with various clinical factors and patient-reported measures. All patients diagnosed with lateral epicondylitis by a single surgeon during a 5-year period were retrospectively reviewed. Age, sex, laterality, hand dominance, pain visual analog scale, duration of symptoms, Quick-Disability of the Arm, Shoulder, and Hand questionnaire score, and history of steroid injection were recorded. Calcifications on standard elbow radiographs, acquired digitally and viewed at 200% magnification on a 24-inch monitor, were characterized by size and relationship with the lateral epicondyle. We reviewed 245 patients diagnosed with lateral epicondylitis. A total of 115 elbows (47%) demonstrated lateral epicondyle calcifications. Patients with and without calcifications were similar with regard to clinical factors, as were patients with larger or smaller lesions. Eighty-five elbows (35%) had additional radiographic findings. Treatment was not altered by the radiographic findings in any case. Lateral epicondyle calcifications are much more common in lateral epicondylitis than previously reported, possibly owing to modern digital radiography and magnification, although they do not appear to be related to clinical factors including patient-reported measures. Thus, patients and surgeons should be careful to avoid overinterpretation of such findings. Although radiographs may be helpful in ruling out additional pathology, we did not find other clinically important contributions to the initial evaluation and management of this condition, and thus we do not recommend their routine use

  16. Chest radiograph interpretation by medical students

    International Nuclear Information System (INIS)

    Jeffrey, D.R.; Goddard, P.R.; Callaway, M.P.; Greenwood, R.

    2003-01-01

    AIM: To assess the ability of final year medical students to interpret conventional chest radiographs. MATERIALS AND METHODS: Ten conventional chest radiographs were selected from a teaching hospital radiology department library that were good radiological examples of common conditions. All were conditions that a medical student should be expected to recognize by the end of their training. One normal radiograph was included. The radiographs were shown to 52 final year medical students who were asked to describe their findings. RESULTS: The median score achieved was 12.5 out of 20 (range 6-18). There was no difference between the median scores of male and female students (12.5 and 12.3, respectively, p=0.82) but male students were more likely to be certain of their answers than female students (median certainty scores 23.0 and 14.0, respectively). The overall degree of certainty was low. On no radiograph were more than 25% of students definite about their answer. Students had received little formal radiology teaching (2-42 h, median 21) and few expressed an interest in radiology as a career. Only two (3.8%) students thought they were good at interpreting chest radiographs, 17 (32.7%) thought they were bad or awful. CONCLUSION: Medical students reaching the end of their training do not perform well at interpreting simple chest radiographs. They lack confidence and have received little formal radiological tuition. Perhaps as a result, few are interested in radiology as a career, which is a matter for concern in view of the current shortage of radiologists in the UK

  17. Hydrodynamic approach to electronic transport in graphene

    Energy Technology Data Exchange (ETDEWEB)

    Narozhny, Boris N. [Institute for Theoretical Condensed Matter Physics, Karlsruhe Institute of Technology, Karlsruhe (Germany); National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation); Gornyi, Igor V. [Institute for Theoretical Condensed Matter Physics, Karlsruhe Institute of Technology, Karlsruhe (Germany); Institute of Nanotechnology, Karlsruhe Institute of Technology, Karlsruhe (Germany); Ioffe Physical Technical Institute, St. Petersburg (Russian Federation); Mirlin, Alexander D. [Institute for Theoretical Condensed Matter Physics, Karlsruhe Institute of Technology, Karlsruhe (Germany); Institute of Nanotechnology, Karlsruhe Institute of Technology, Karlsruhe (Germany); Petersburg Nuclear Physics Institute, St. Petersburg (Russian Federation); Schmalian, Joerg [Institute for Theoretical Condensed Matter Physics, Karlsruhe Institute of Technology, Karlsruhe (Germany); Institute for Solid State Physics, Karlsruhe Institute of Technology, Karlsruhe (Germany)

    2017-11-15

    The last few years have seen an explosion of interest in hydrodynamic effects in interacting electron systems in ultra-pure materials. In this paper we briefly review the recent advances, both theoretical and experimental, in the hydrodynamic approach to electronic transport in graphene, focusing on viscous phenomena, Coulomb drag, non-local transport measurements, and possibilities for observing nonlinear effects. (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Improvements to SOIL: An Eulerian hydrodynamics code

    International Nuclear Information System (INIS)

    Davis, C.G.

    1988-04-01

    Possible improvements to SOIL, an Eulerian hydrodynamics code that can do coupled radiation diffusion and strength of materials, are presented in this report. Our research is based on the inspection of other Eulerian codes and theoretical reports on hydrodynamics. Several conclusions from the present study suggest that some improvements are in order, such as second-order advection, adaptive meshes, and speedup of the code by vectorization and/or multitasking. 29 refs., 2 figs

  19. Relabeling symmetries in hydrodynamics and magnetohydrodynamics

    International Nuclear Information System (INIS)

    Padhye, N.; Morrison, P.J.

    1996-04-01

    Lagrangian symmetries and concomitant generalized Bianchi identities associated with the relabeling of fluid elements are found for hydrodynamics and magnetohydrodynamics (MHD). In hydrodynamics relabeling results in Ertel's theorem of conservation of potential vorticity, while in MHD it yields the conservation of cross helicity. The symmetries of the reduction from Lagrangian (material) to Eulerian variables are used to construct the Casimir invariants of the Hamiltonian formalism

  20. Australian rural radiographers' perspectives on disclosure of their radiographic opinion to patients

    International Nuclear Information System (INIS)

    Squibb, Kathryn; Bull, Rosalind M.; Smith, Anthony; Dalton, Lisa

    2015-01-01

    The role of Australian rural radiographers in radiographic interpretation, communication and disclosure of their radiographic opinion with a specific focus on plain film radiography was examined in a two phase, exploratory interpretive study. Data were collected using questionnaires and interviews and analysed thematically. This reports one of the key themes identified in the thematic data analysis. ‘Disclosure of Radiographic Opinion to Patients’ comprises the three interrelated sub-themes Acting Ethically, Selective Disclosure and Filtered Truth. It is wholly concerned with the ways in which rural radiographers choose to disclose their radiographic opinion to patients. Without a clear picture of where they stand medico-legally, rural radiographers draw on experience and a strong ethical framework as the basis for these complex decisions. Rural radiographers frame their disclosures to patients in a manner that is governed by the diagnostic, therapeutic and emotional impact the information disclosed may have on the patient. Disclosure to patients was found to be selective, often diagnostically vague and ethically filtered

  1. Radiographic testing - optimum radiographs of plastics and composite materials with dosimeter control

    International Nuclear Information System (INIS)

    Kuster, J.

    1978-01-01

    In view of great differencies in X-ray transmission it is more difficult to get optimum radiographs of plastics and especially of reinforced plastics than for example of metals. A procedure will be reported how to get with little effort optimum radiographs especially also in the range of long wavelength radiation corresponding 10 to 25 kV.P. (orig.) [de

  2. Shock-hydrodynamics experiments on the Nova laser

    International Nuclear Information System (INIS)

    Miller, P.; Peyser, T.; Stry, P.; Budil, K.; Wojtowicz, D.; Burke, E.

    1995-08-01

    We have conducted shock-induced hydrodynamics experiments using the Nova laser at Lawrence Livermore National Laboratory. The laser provides a high-enthalpy source by depositing its energy (about 22 kJ) in a small gold cavity called a Hohlraum. The Hohlraum serves as a driver section, launching very strong (M ∼ 20) shocks into millimeter-scale cylindrical ''shock tubes.'' The flow is imaged radiographically by an electronic framing camera, using a laser-generated x-ray source. Several topics have been addressed with this configuration, including shock-induced mixing at density interfaces (seeded with a variety of perturbations); the development of high-speed, shaped-charge-like jets; the effects of geometry on the planarity of the generated shocks; and shock-shock interactions which develop in the flows. This paper describes the general configuration of our experiments, presents an overview of the high-speed jet work, discusses some of our findings, and compares our results with computer simulations

  3. Radiographic study on temporomandibular joint Arthrosis

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Dong Soo [Dept. of Radiology, College of Dentistry, Seoul National University , Seoul (Korea, Republic of)

    1980-11-15

    The author analysed the routine radiographic changes and clinical symptoms of 205 cases of temporomandibular joint arthrosis. The clinical symptoms of the patients were classified and the morphological changes of condylar head, articular eminence, and articular fossa were analyzed and discussed from radiographic view point. The positional change of condylar head and articular fossa relation in TMJ arthrosis were observed. The frequencies of coincidence between the site of complaints and the site of the abnormal images which could be detected were examined. The results were obtained as follows; 1. Bone erosion, deformity, marginal proliferation and sclerosis were selected from many abnormal images as the radiographic diagnostic criteria of TMJ arthritic lesions. 2. Abnormal radiographic findings were revealed in 150 cases (73.9%) of 205 total TMJ arthrosis cases and site with abnormal findings coincided with the site of complaints in 105 cases (70.7%) of 150 cases and coincidence rates were higher above fourth decades than below third decades. 3. Sclerosis of the abnormal radiographic findings could be found more often below third decades than above fourth decades. 4. The positional changes of condylar head were revealed in 176 cases (85.9%) of 205 total cases. 5. Pain complaints were revealed in 170 cases(82.9%) and clicking sounds were revealed in 120 cases (58.6%) of clinical symptoms of TMJ arthrosis. 6. No tendency was found so far the differential diagnosis between pain dysfunction syndrome and osteoarthrosis of TMJ.

  4. Radiographic study on temporomandibular joint Arthrosis

    International Nuclear Information System (INIS)

    Yoo, Dong Soo

    1980-01-01

    The author analysed the routine radiographic changes and clinical symptoms of 205 cases of temporomandibular joint arthrosis. The clinical symptoms of the patients were classified and the morphological changes of condylar head, articular eminence, and articular fossa were analyzed and discussed from radiographic view point. The positional change of condylar head and articular fossa relation in TMJ arthrosis were observed. The frequencies of coincidence between the site of complaints and the site of the abnormal images which could be detected were examined. The results were obtained as follows; 1. Bone erosion, deformity, marginal proliferation and sclerosis were selected from many abnormal images as the radiographic diagnostic criteria of TMJ arthritic lesions. 2. Abnormal radiographic findings were revealed in 150 cases (73.9%) of 205 total TMJ arthrosis cases and site with abnormal findings coincided with the site of complaints in 105 cases (70.7%) of 150 cases and coincidence rates were higher above fourth decades than below third decades. 3. Sclerosis of the abnormal radiographic findings could be found more often below third decades than above fourth decades. 4. The positional changes of condylar head were revealed in 176 cases (85.9%) of 205 total cases. 5. Pain complaints were revealed in 170 cases(82.9%) and clicking sounds were revealed in 120 cases (58.6%) of clinical symptoms of TMJ arthrosis. 6. No tendency was found so far the differential diagnosis between pain dysfunction syndrome and osteoarthrosis of TMJ.

  5. Radiographers' preconditions for evidence-based radiography

    International Nuclear Information System (INIS)

    Ahonen, Sanna-Mari; Liikanen, Eeva

    2010-01-01

    Evidence-based practice (EBP) is essential in today's health care, but its establishment requires several preconditions from individuals and organizations (e.g. knowledge, understanding, attitudes, abilities, self-confidence, support, and resources). Previous studies suggest that radiographers do generate and use evidence in their work, but evidence-based radiography (EBR) is not yet used routinely as established practice, especially in terms of research utilization. This paper aims to describe radiographers' preconditions for EBR, and their participation in research activities. Main focus is on research utilization. Using an electronic questionnaire developed for this study, a survey was conducted: data collected from Finnish radiographers and radiotherapists (N = 438) were analysed both statistically and qualitatively. The final response rate was 39%. The results suggest radiographers' preconditions for EBR to consist of knowledge of research, significance of research activities, research-orientated way of working, and support. In addition, adequate resourcing is essential. Reading scientific journals, participation in research activities, a higher degree of education, and senior post seem to be significant promoters of EBR and research utilization. The results support the notion that EBR, and especially research utilization, are not yet well-established in Finland, and radiographers' viewpoints concerning the role and significance of research evidence and research activities still seem to vary.

  6. Radiographic evaluation of the diabetic foot

    International Nuclear Information System (INIS)

    Jacobs, A.M.

    1989-01-01

    Radiographic evaluation of the foot in the patient with diabetes mellitus is discussed in this paper. According to the author, it can only be of value when the soft tissue and bony and joint pathologic conditions, which occur more frequently in the diabetic patient are also considered and understood. Although not pathognomic for diabetes mellitus, neuroarthopathy, osteomyelitis, soft tissue infection, and some rheumatic disorders are present with greater frequency in diabetic populations than in non-diabetic populations. Frequently, edema, erythema, hyperthermia, and tenderness are present as nonspecific clinical findings, in which case radiographic evaluation is called upon to define the specific etiology of a particular patient's pathology. Unfortunately, many radiographic, computerized tomographic, and radionuclide studies demonstrate less than optimal positive and negative predictive values unless interpreted in view of clinical history and examination and integrated with the results of other laboratory data. Radiographic evaluation of the diabetic foot may be utilized to establish the presence of disease, the extent of pedal involvement, and the response to therapy. The establishment of the nature of disease processes from radiographic findings alone, however, may be problematic. The diagnosis of osteomyelitis, for example, rests on the recovery of the offending microorganisms from bone aspiration or culture

  7. Chaotic hydrodynamics of fluidized beds

    Energy Technology Data Exchange (ETDEWEB)

    Van der Stappen, M.L.M. [Unit Process and Systems Engineering, Advanced Manufacturing Technology Group, Unilever Research Laboratorium, Vlaardingen (Netherlands)

    1996-12-31

    The major goals of this thesis are: (1) to develop and evaluate an analysis method based on techniques from non-linear chaos theory to characterize the nonlinear hydrodynamics of gas-solids fluidized beds quantitatively; and (2) to determine the dependence of the chaotic invariants on the operating conditions and investigate how the chaos analysis method can be profitably applied to improve scale-up and design of gas-solids fluidized bed reactors. Chaos theory is introduced in chapter 2 with emphasis on analysis techniques for (experimental) time series, known from literature at the start of this work (1990-1991). In chapter 3, the testing of existing and newly developed techniques on both model and fluidized bed data is described. This leads to the development of the chaos analysis method to analyze measured pressure fluctuations time series of a fluidized bed. Following, in chapter 4, this method is tested and all choices for the parameters are evaluated. The influence of the experimental parameters and external disturbances on the measurements and analysis results is discussed and quantified. The result is a chaos measurement and analysis protocol, which is further used in this work. In chapter 5, the applications to fluidized beds are discussed. It is shown that the entropy is a good measure for the characterization of the dynamical behavior of gas-solids bubbling/slugging fluidized beds. Entropy is applied to characterize the influence of the operating conditions, to assess regime transitions and to analyze dimensionless similar beds of different scale. Quantitative design correlations that relate entropy to the operating parameters (including the bed diameter) are described. Finally, it is discussed how the results of this work might be used in scaling up the chaotic dynamics of fluidized beds. The overall conclusions and outlook from this work are presented in chapter 6. 182 refs.

  8. Hydrodynamics of soft active matter

    Science.gov (United States)

    Marchetti, M. C.; Joanny, J. F.; Ramaswamy, S.; Liverpool, T. B.; Prost, J.; Rao, Madan; Simha, R. Aditi

    2013-07-01

    This review summarizes theoretical progress in the field of active matter, placing it in the context of recent experiments. This approach offers a unified framework for the mechanical and statistical properties of living matter: biofilaments and molecular motors in vitro or in vivo, collections of motile microorganisms, animal flocks, and chemical or mechanical imitations. A major goal of this review is to integrate several approaches proposed in the literature, from semimicroscopic to phenomenological. In particular, first considered are “dry” systems, defined as those where momentum is not conserved due to friction with a substrate or an embedding porous medium. The differences and similarities between two types of orientationally ordered states, the nematic and the polar, are clarified. Next, the active hydrodynamics of suspensions or “wet” systems is discussed and the relation with and difference from the dry case, as well as various large-scale instabilities of these nonequilibrium states of matter, are highlighted. Further highlighted are various large-scale instabilities of these nonequilibrium states of matter. Various semimicroscopic derivations of the continuum theory are discussed and connected, highlighting the unifying and generic nature of the continuum model. Throughout the review, the experimental relevance of these theories for describing bacterial swarms and suspensions, the cytoskeleton of living cells, and vibrated granular material is discussed. Promising extensions toward greater realism in specific contexts from cell biology to animal behavior are suggested, and remarks are given on some exotic active-matter analogs. Last, the outlook for a quantitative understanding of active matter, through the interplay of detailed theory with controlled experiments on simplified systems, with living or artificial constituents, is summarized.

  9. Radiographic findings in tuberculosis of the calvarium

    Energy Technology Data Exchange (ETDEWEB)

    Patankar, T.; Varma, R.; Krishnan, A.; Prasad, S. [Dept. of Radiology, King Edward Memorial Hospital, Parel, Bombay (India); Desai, K. [Dept. of Neurosurgery, King Edward Memorial Hospital, Bombay (India); Castillo, M. [Dept. of Radiology, University of North Carolina School of Medicine, Chapel Hill, NC (United States)

    2000-07-01

    We reviewed the pattern of involvement of the calvarium by tuberculosis (TB) in five patients and the role of imaging in its management. Four patients presented with localised scalp swelling and one with generalized seizures. Radiographs revealed lucent lesions with minimal surrounding sclerosis in the frontal (2), parietal (2) and occipital (1) bones. CT showed lesions involving the entire thickness of the calvarium and accompanying contrast-enhancing soft tissue. The patient presenting with seizures had a ring-enhancing lesion in the parietal lobe in addition to the extra-axial lesions. Although radiographs in all cases demonstrated calvarial TB, CT showed the extent of the defect, involvement of adjacent soft tissues, and in one case an intra-axial lesion. Radiographs suffice for follow-up of these patients. (orig.)

  10. Understanding chest radiographic anatomy with MDCT reformations

    Energy Technology Data Exchange (ETDEWEB)

    Sussmann, A.R. [Department of Radiology, Thoracic Imaging, NYU Langone Medical Center, New York, NY (United States); Ko, J.P., E-mail: jane.ko@nyumc.or [Department of Radiology, Thoracic Imaging, NYU Langone Medical Center, New York, NY (United States)

    2010-02-15

    Chest radiograph interpretation requires an understanding of the mediastinal reflections and anatomical structures. Computed tomography (CT) improves the learning of three-dimensional (3D) anatomy, and more recently multidetector CT (MDCT) technology has enabled the creation of high-quality reformations in varying projections. Multiplanar reformations (MPRs) of varying thickness in the coronal and sagittal projections can be created for direct correlation with findings on frontal and lateral chest radiographs, respectively. MPRs enable simultaneous visualization of the craniocaudal extent of thoracic structures while providing the anatomic detail that has been previously illustrated using cadaveric specimens. Emphasis will be placed on improving knowledge of mediastinal anatomy and reflections including edges, lines, and stripes that are visible on chest radiographs.

  11. Radiographic abnormalities in tricyclic acid overdose

    International Nuclear Information System (INIS)

    Varnell, R.M.; Richardson, M.L.; Vincent, J.M.; Godwin, J.D.

    1987-01-01

    Several case reports have described adult respiratory distress syndrome (ARDS) secondary to tricyclic acid (TCA) overdose. During a 1-year period 83 patients requiring intubation secondary to drug overdose were evaluated. Abnormalities on chest radiographs occurred in 26 (50%) of the 54 patients with TCA overdose, compared to six (21%) of the 29 patients overdosed with other drugs. In addition, five (9%) of the patients with TCA overdose subsequently had radiographic and clinical abnormalities meeting the criteria for ARDS. Only one (3%) of the patients with non-TCA overdose subsequently had change suggesting ARDS. TCAs should be added to the list of drugs associated with ARDS, and TCA overdose should be considered a major risk factor in the development of radiographically evident abnormalities

  12. Opportunistic esophagitis in AIDS: Radiographic diagnosis

    International Nuclear Information System (INIS)

    Levine, M.S.; Woldenberg, R.; Herlinger, H.; Laufer, I.

    1987-01-01

    Between 1983 and 1986, 35 of 90 patients with acquired immunodeficiency syndrome (AIDS) had double-contrast esophagograms to rule out opportunistic esophagitis. The radiographs were reviewed without knowledge of the clinical or endoscopic findings. Candida esophagitis was diagnosed radiographically in 17 patients who had varying degrees of plaque formation and viral esophagitis in three who had discrete ulcers without plaques. All three patients with viral esophagitis (herpes in 2 and cytomegalo virus in one) and 15 of 17 with Candida esophagitis had endoscopic and/or clinical corroboration of the radiographic diagnosis. Thus, the authors' experience suggests that fungal and viral esophagitis can often be differentiated on double-contrast esophagography, so that appropriate antifungal or antiviral therapy can be instituted without need for endoscopic intervention

  13. Development of low-silver radiographic detectors

    International Nuclear Information System (INIS)

    Troitskij, V.A.; Novikov, I.A.; Nikitin, V.F.; Krasnyj-Admoni, L.V.; Valevich, M.I.; Belyj, N.G.; Grom, V.S.

    1988-01-01

    The results of investigations on radiographic testing of welded joints of St20, 08Kh18N10T steels, the AMG-6 alloy, copper, titanium using radiographic detectors with the low silver content are presented. The roentgenographic and photographic paper, as well as the samples of experimental films with heavy elements in the photolayer are tested using intensifying screens of different types. Experimental films containing silver 2 times as less as standard X-ray films are shown to provide the similar sensitivity of testing under equal conditions, but the exposure time is two times higher. Prints on the radiophotographic paper in quality and exposure time approach to prints obtained on the RT-1 film containing silver 10 times less than that in the roentgenographic film. The exposure time of the radiographic paper is several times less than that of the ''unibrom'' contrast paper. The testing sensitivity decreases to some extent in this case

  14. Initial image interpretation of appendicular skeletal radiographs: A comparison between nurses and radiographers

    International Nuclear Information System (INIS)

    Piper, Keith J.; Paterson, Audrey

    2009-01-01

    Purpose: To examine the effect of a short training programme on nurses and radiographers, exploring differences between their performance before and after training. Method: Twenty-two nurses and 18 radiographers interpreted 20 trauma radiographs of the appendicular skeleton before and after training. Normal and abnormal cases of a discriminatory nature were included. Total score, sensitivity and specificity values were calculated for each participant by comparison with an agreed expected answer. The area under the curve (AUC) was analysed using alternate free-response receiver operating characteristic (AFROC) methodology. Results: Significant differences were demonstrated between the total scores achieved by the two groups (pre-training: p = 0.007, post-training: p = 0.04). After training, the mean score increased significantly for both groups (p < 0.001). No significant difference was found between the radiographers mean pre-training scores and the nurses mean post-training scores (p = 0.66). Sensitivity for both groups increased following training, significantly so for the nurses (nurses: p < 0.001, radiographers: p = 0.06). Specificity reduced significantly after training for the nurses (p < 0.001), and increased for the radiographers but not significantly (p = 0.085). After training, there was no significant difference between the two groups in terms of sensitivity (p = 0.09) but specificity was significantly higher for the radiographers (p < 0.001). The radiographers achieved higher pre-training AUC values than the nurses (p = 0.04), although a difference remained after training this did not achieve statistical significance (p = 0.15). The AUC values increased significantly after training for both groups (nurses: p = 0.012, radiographers: p = 0.004) and again there was no significant difference between the radiographers pre-training performance and the nurses post-training performance (p = 0.62). Conclusion: Improvement after training was seen in both groups

  15. Radiographic indices for lumbar developmental spinal stenosis

    Directory of Open Access Journals (Sweden)

    Jason Pui Yin Cheung

    2017-02-01

    Full Text Available Abstract Background Patients with developmental spinal stenosis (DSS are susceptible to developing symptomatic stenosis due to pre-existing narrowed spinal canals. DSS has been previously defined by MRI via the axial anteroposterior (AP bony spinal canal diameter. However, MRI is hardly a cost-efficient tool for screening patients. X-rays are superior due to its availability and cost, but currently, there is no definition of DSS based on plain radiographs. Thus, the aim of this study is to develop radiographic indices for diagnosing DSS. Methods This was a prospective cohort of 148 subjects consisting of patients undergoing surgery for lumbar spinal stenosis (patient group and asymptomatic subjects recruited openly from the general population (control group. Ethics approval was obtained from the local institutional review board. All subjects underwent MRI for diagnosing DSS and radiographs for measuring parameters used for creating the indices. All measurements were performed by two independent investigators, blinded to patient details. Intra- and interobserver reliability analyses were conducted, and only parameters with near perfect intraclass correlation underwent receiver operating characteristic (ROC analysis to determine the cutoff values for diagnosing DSS using radiographs. Results Imaging parameters from a total of 66 subjects from the patient group and 82 asymptomatic subjects in the control group were used for analysis. ROC analysis suggested sagittal vertebral body width to pedicle width ratio (SBW:PW as having the strongest sensitivity and specificity for diagnosing DSS. Cutoff indices for SBW:PW were level-specific: L1 (2.0, L2 (2.0, L3 (2.2, L4 (2.2, L5 (2.5, and S1 (2.8. Conclusions This is the first study to define DSS on plain radiographs based on comparisons between a clinically relevant patient group and a control group. Individuals with DSS can be identified by a simple radiograph using a screening tool allowing for better

  16. Optimizing radiation exposure for CT localizer radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Bohrer, Evelyn; Maeder, Ulf; Fiebich, Martin [Univ. of Applied Sciences, Giessen (Germany). Inst. of Medical Physics and Radiation Protection-IMPS; Schaefer, Stefan; Krombach, Gabriele A. [Univ. Hospital Giessen (Germany). Dept. of Radiology; Noel, Peter B. [Technische Univ. Muenchen (Germany). Dept. of Diagnostic and Interventional Radiology

    2017-08-01

    The trend towards submillisievert CT scans leads to a higher dose fraction of localizer radiographs in CT examinations. The already existing technical capabilities make dose optimization of localizer radiographs worthwhile. Modern CT scanners apply automatic exposure control (AEC) based on attenuation data in such a localizer. Therefore not only this aspect but also the detectability of anatomical landmarks in the localizer for the desired CT scan range adjustment needs to be considered. The effective dose of a head, chest, and abdomen-pelvis localizer radiograph with standard factory settings and user-optimized settings was determined using Monte Carlo simulations. CT examinations of an anthropomorphic phantom were performed using multiple sets of acquisition parameters for the localizer radiograph and the AEC for the subsequent helical CT scan. Anatomical landmarks were defined to assess the image quality of the localizer. CTDI{sub vol} and effective mAs per slice of the helical CT scan were recorded to examine the impact of localizer settings on a helical CT scan. The dose of the localizer radiograph could be decreased by more than 90% while the image quality remained sufficient when selecting the lowest available settings (80 kVp, 20 mA, pa tube position). The tube position during localizer acquisition had a greater impact on the AEC than the reduction of tube voltage and tube current. Except for the use of a pa tube position, all changes of acquisition parameters for the localizer resulted in a decreased total radiation exposure. A dose reduction of CT localizer radiograph is necessary and possible. In the examined CT system there was no negative impact on the modulated helical CT scan when the lowest tube voltage and tube current were used for the localizer.

  17. Pseudoprominent aorta: Radiographic findings and CT correlation

    International Nuclear Information System (INIS)

    Brown, K.T.; Shepard, J.A.O.; Stewart, W.J.

    1985-01-01

    The presence of a persistent left-sided superior vena cava (LSVC) in the absence of a right-sided superior vena cava (RSVC) may be suspected on a posteroanterior (PA) chest radiograph because of a prominent-appearing ascending aorta, which results from the absence of the RSVC. In the absence of an RSVC, the right upper lobe abuts and outlines the course of the ascending aorta, allowing better demonstration of its profile. This report describes a patient with this finding on a PA chest radiograph. Computed tomographic correlation is presented

  18. Inferior hilar window on lateral chest radiographs

    International Nuclear Information System (INIS)

    Park, C.K.; Webb, W.R.; Klein, J.S.

    1990-01-01

    This paper determines the accuracy of lateral chest radiography in the detection of masses in the inferior hilar window, a normally avascular hilar region anterior to the lower lobe bronchi. Fifty patients with normal thoracic CT scans and 25 with hilar masses/adenopathy were selected retrospectively. The 75 corresponding lateral chest radiographs were blindly evaluated for visibility of the anterior walls of the lower lobe bronchi and the presence and laterality of abnormal soft tissue (>1 cm) in the inferior hilar window. Only a 7 x 7-cm square of the lateral radiograph was viewed

  19. Pelvic radiograph in skeletal dysplasias: An approach

    Directory of Open Access Journals (Sweden)

    Manisha Jana

    2017-01-01

    Full Text Available The bony pelvis is constituted by the ilium, ischium, pubis, and sacrum. The pelvic radiograph is an important component of the skeletal survey performed in suspected skeletal dysplasia. Most of the common skeletal dysplasias have either minor or major radiological abnormalities; hence, knowledge of the normal radiological appearance of bony pelvis is vital for recognizing the early signs of various skeletal dysplasias. This article discusses many common and some uncommon radiological findings on pelvic radiographs along with the specific dysplasia in which they are seen; common differential diagnostic considerations are also discussed.

  20. The one-leg standing radiograph

    OpenAIRE

    Pinsornsak, P.; Naratrikun, K.; Kanitnate, S.; Sangkomkamhang, T.

    2016-01-01

    Objectives The purpose of this study was to compare the joint space width between one-leg and both-legs standing radiographs in order to diagnose a primary osteoarthritis of the knee. Methods Digital radiographs of 100 medial osteoarthritic knees in 50 patients were performed. The patients had undergone one-leg standing anteroposterior (AP) views by standing on the affected leg while a both-legs standing AP view was undertaken while standing on both legs. The severity of the osteoarthritis wa...

  1. Cardiac and pericardial calcifications on chest radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Ferguson, E.C., E-mail: ecferguson@hotmail.co [University of Texas Medical School at Houston, Department of Diagnostic and Interventional Imaging, Section of Thoracic Imaging, Houston, TX 77030 (United States); Berkowitz, E.A. [University of Texas Medical School at Houston, Department of Diagnostic and Interventional Imaging, Section of Thoracic Imaging, Houston, TX 77030 (United States)

    2010-09-15

    Many types of cardiac and pericardial calcifications identified on chest radiographs can be recognized and distinguished based on characteristic locations and appearances. The purpose of this review is to emphasize the importance of detecting cardiac and pericardial calcifications on chest radiographs, and to illustrate and describe the various types of calcifications that may be encountered and how they may be differentiated from one another. Each type of cardiac and pericardial calcification is discussed, its location and appearance described, and its significance explained. Recognizing and understanding these calcifications is important as they are often encountered in daily practice and play an important role in patient care.

  2. Pattern of scattered exposure from portable radiographs

    International Nuclear Information System (INIS)

    North, D.

    1985-01-01

    Concern periodically arises among the nursing and medical staffs of the institution's intensive care unit regarding their occupational exposure to radiation from the many radiographs taken in the unit. The patients are located in open areas or within individual cubicles whose walls are relatively thin and not shielded. To form a data base for educating the nursing/medical staffs and the technologists, the intensity and distribution of scattered exposure from actual radiographs of patients were measured. Comparison was also made with a simple phantom experiment in which the variables could be more precisely controlled

  3. Diagnosis of calcification on abdominal radiographs

    International Nuclear Information System (INIS)

    Lamb, C.R.; Kleine, L.J.; McMillan, M.C.

    1991-01-01

    A wide variety of normal and pathologic factors may induce intraabdominal calcification. In general, the most reliable indication of the cause of a calcification is its location; therefore, if the affected organ can be identified the radiographic diagnosis is often straightforward or, at least, limited to relatively few possibilities. With this principle in mind, a series of patients with abdominal calcification are described for the purpose of illustrating the appearance of calcification of various abdominal organs. In addition, etiology for the calcification in each patient is discussed. Certain extraabdominal calcifications which may be seen on abdominal radiographs are also mentioned

  4. Pseudoprominent aorta: Radiographic findings and CT correlation

    Energy Technology Data Exchange (ETDEWEB)

    Brown, K.T.; Shepard, J.A.O.; Stewart, W.J.

    1985-05-01

    The presence of a persistent left-sided superior vena cava (LSVC) in the absence of a right-sided superior vena cava (RSVC) may be suspected on a posteroanterior (PA) chest radiograph because of a prominent-appearing ascending aorta, which results from the absence of the RSVC. In the absence of an RSVC, the right upper lobe abuts and outlines the course of the ascending aorta, allowing better demonstration of its profile. This report describes a patient with this finding on a PA chest radiograph. Computed tomographic correlation is presented.

  5. Evaluation of contrast in duplicated radiographs

    International Nuclear Information System (INIS)

    Thunthy, K.H.; Weinberg, R.

    1982-01-01

    This investigation evaluated changes in the contrast of duplicated radiographs made at different ultraviolet light exposures. Increasing ultraviolet light exposure had different effects on the duplicates of originals of different background densities. When correctly exposed, a duplicate radiograph enhanced contrast. When originals had the same contrast but different background densities, their duplicates did not have the same contrast. It was not possible to duplicate accurately all the different contrasts measured on an original. It was possible, however, to produce duplicates with all contrasts greater than those of the original

  6. A radiographic study of the position and shape of mental foramen in panoramic radiographs

    International Nuclear Information System (INIS)

    Choi, Karp Shik; Kim, Dong Youn; Sohn, Jeong Ick; Bae, Yong Chul

    1997-01-01

    The purpose of this study was to evaluate the position and shape of mental foramen in panoramic radiographs. For this study, panoramic radiographs were obtained from the 200 adults and evaluated the position and shape of mental foramen. According to various positional changes in panoramic radiographs of the patients, the author also obtained panoramic radiographs from the 100 adults and then evaluated the positional and shape changes of mental foramen. The following results were obtained : 1. Shapes of mental foramen were observed elliptical (43.3%), round or oval (42.5%), unidentified (7.5%) and diffuse (6.7%) type in descending order of frequency. 2. Horizontal position of mental foramen were most frequently observed at the 2nd premolar area (54.2%), and area between the 1st premolar and 2nd premolar (43.1%), area between the 2nd premolar and 1st molar (2.7%), and at apex (9.7%), overlap with apex (1.9%), superior of apex (0.2%) in descending order of frequency. 4. According to various positional changes in panoramic radiographs of the patients, shape changes of mental foramen were more obviously observed at the forward 10 mm and chin down 10 degree positioned panoramic radiographs, And changes of horizontal and vertical position were observed in similar to compared with normal positioned panoramic radiographs.

  7. The radiographer's role in child protection: Comparison of radiographers perceptions by use of focus groups

    International Nuclear Information System (INIS)

    Davis, Michaela; Reeves, Pauline

    2006-01-01

    The research presented in this paper is taken from a larger study whose aims were to devise a holistic picture of how diagnostic radiographers approach child protection issues and to explore how radiographers and other professionals see the role of radiographers in the chain of evidence in relation to child protection as this applies to children who present at the Imaging Department with suspected non-accidental injuries (NAI). A focus group methodology was used with focus groups being conducted in the United Kingdom and Republic of Ireland. The results indicated that both United Kingdom and Republic of Ireland radiographers agreed that they had a role in child protection; however, they identified a wide interpretation as to the extent of that role. Although radiographers in the United Kingdom and Republic of Ireland work within different legal systems there were themes identified which were common to both countries. Although radiographers referred to a duty to the child as to all patients, no radiographer specifically mentioned the system and child care law under which it is assumed they operate. This research revealed an area which would benefit from more detailed research using a wider audience. However, the study revealed a need for training in relation to possible NAI indicators and the correct procedure for documenting their suspicions and initiating an NAI referral

  8. Three-dimensional hindfoot alignment measurements based on biplanar radiographs: comparison with standard radiographic measurements

    International Nuclear Information System (INIS)

    Sutter, Reto; Pfirrmann, Christian W.A.; Buck, Florian M.; Espinosa, Norman

    2013-01-01

    To establish a hindfoot alignment measurement technique based on low-dose biplanar radiographs and compare with hindfoot alignment measurements on long axial view radiographs, which is the current reference standard. Long axial view radiographs and low-dose biplanar radiographs of a phantom consisting of a human foot skeleton embedded in acrylic glass (phantom A) and a plastic model of a human foot in three different hindfoot positions (phantoms B1-B3) were imaged in different foot positions (20 internal to 20 external rotation). Two independent readers measured hindfoot alignment on long axial view radiographs and performed 3D hindfoot alignment measurements based on biplanar radiographs on two different occasions. Time for three-dimensional (3D) measurements was determined. Intraclass correlation coefficients (ICC) were calculated. Hindfoot alignment measurements on long axial view radiographs were characterized by a large positional variation, with a range of 14 /13 valgus to 22 /27 varus (reader 1/2 for phantom A), whereas the range of 3D hindfoot alignment measurements was 7.3 /6.0 to 9.0 /10.5 varus (reader 1/2 for phantom A), with a mean and standard deviation of 8.1 ± 0.6/8.7 ± 1.4 respectively. Interobserver agreement was high (ICC = 0.926 for phantom A, and ICC = 0.886 for phantoms B1-B3), and agreement between different readouts was high (ICC = 0.895-0.995 for reader 1, and ICC = 0.987-0.994 for reader 2) for 3D measurements. Mean duration of 3D measurements was 84 ± 15/113 ± 15 s for reader 1/2. Three-dimensional hindfoot alignment measurements based on biplanar radiographs were independent of foot positioning during image acquisition and reader independent. In this phantom study, the 3D measurements were substantially more precise than the standard radiographic measurements. (orig.)

  9. Radiographer commenting of trauma radiographs: a survey of the benefits, barriers and enablers to participation in an Australian healthcare setting

    International Nuclear Information System (INIS)

    Neep, Michael J.; Steffens, Tom; Owen, Rebecca; McPhail, Steven M.

    2014-01-01

    Radiographer abnormality detection systems that highlight abnormalities on trauma radiographs ('red dot' system) have been operating for more than 30 years. Recently, a number of pitfalls have been identified. These limitations initiated the evolution of a radiographer commenting system, whereby a radiographer provides a brief description of abnormalities identified in emergency healthcare settings. This study investigated radiographers' participation in abnormality detection systems, their perceptions of benefits, barriers and enablers to radiographer commenting, and perceptions of potential radiographer image interpretation services for emergency settings. A cross-sectional survey was implemented. Participants included radiographers from four metropolitan hospitals in Queensland, Australia. Conventional descriptive statistics, histograms and thematic analysis were undertaken. Seventy-three surveys were completed and included in the analysis (68% response rate); 30 (41%) of respondents reported participating in abnormality detection in 20% or less of examinations, and 26(36%) reported participating in 80% or more of examinations. Five overarching perceived benefits of radiographer commenting were identified: assisting multidisciplinary teams, patient care, radiographer ability, professional benefits and quality of imaging. Frequently reported perceived barriers included 'difficulty accessing image interpretation education', 'lack of time' and 'low confidence in interpreting radiographs'. Perceived enablers included 'access to image interpretation education' and 'support from radiologist colleagues'. A range of factors are likely to contribute to the successful implementation of radiographer commenting in addition to abnormality detection in emergency settings. Effective image interpretation education amenable to completion by radiographers would likely prove valuable in preparing radiographers for participation in abnormality detection and commenting systems in

  10. Anisotropic hydrodynamics for conformal Gubser flow

    Energy Technology Data Exchange (ETDEWEB)

    Strickland, Michael; Nopoush, Mohammad [Kent State University, Kent OH 44242 (United States); Ryblewski, Radoslaw [The H. Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences, PL-31342 Kraków (Poland)

    2016-12-15

    In this proceedings contribution, we review the exact solution of the anisotropic hydrodynamics equations for a system subject to Gubser flow. For this purpose, we use the leading-order anisotropic hydrodynamics equations which assume that the distribution function is ellipsoidally symmetric in local-rest-frame momentum. We then prove that the SO(3){sub q} symmetry in de Sitter space constrains the anisotropy tensor to be of spheroidal form with only one independent anisotropy parameter remaining. As a consequence, the exact solution reduces to the problem of solving two coupled non-linear differential equations. We show that, in the limit that the relaxation time goes to zero, one obtains Gubser's ideal hydrodynamic solution and, in the limit that the relaxation time goes to infinity, one obtains the exact free streaming solution obtained originally by Denicol et al. For finite relaxation time, we solve the equations numerically and compare to the exact solution of the relaxation-time-approximation Boltzmann equation subject to Gubser flow. Using this as our standard, we find that anisotropic hydrodynamics describes the spatio-temporal evolution of the system better than all currently known dissipative hydrodynamics approaches.

  11. Hydrodynamic Modeling and Its Application in AUC.

    Science.gov (United States)

    Rocco, Mattia; Byron, Olwyn

    2015-01-01

    The hydrodynamic parameters measured in an AUC experiment, s(20,w) and D(t)(20,w)(0), can be used to gain information on the solution structure of (bio)macromolecules and their assemblies. This entails comparing the measured parameters with those that can be computed from usually "dry" structures by "hydrodynamic modeling." In this chapter, we will first briefly put hydrodynamic modeling in perspective and present the basic physics behind it as implemented in the most commonly used methods. The important "hydration" issue is also touched upon, and the distinction between rigid bodies versus those for which flexibility must be considered in the modeling process is then made. The available hydrodynamic modeling/computation programs, HYDROPRO, BEST, SoMo, AtoB, and Zeno, the latter four all implemented within the US-SOMO suite, are described and their performance evaluated. Finally, some literature examples are presented to illustrate the potential applications of hydrodynamics in the expanding field of multiresolution modeling. © 2015 Elsevier Inc. All rights reserved.

  12. Anisotropic hydrodynamics for conformal Gubser flow

    International Nuclear Information System (INIS)

    Strickland, Michael; Nopoush, Mohammad; Ryblewski, Radoslaw

    2016-01-01

    In this proceedings contribution, we review the exact solution of the anisotropic hydrodynamics equations for a system subject to Gubser flow. For this purpose, we use the leading-order anisotropic hydrodynamics equations which assume that the distribution function is ellipsoidally symmetric in local-rest-frame momentum. We then prove that the SO(3)_q symmetry in de Sitter space constrains the anisotropy tensor to be of spheroidal form with only one independent anisotropy parameter remaining. As a consequence, the exact solution reduces to the problem of solving two coupled non-linear differential equations. We show that, in the limit that the relaxation time goes to zero, one obtains Gubser's ideal hydrodynamic solution and, in the limit that the relaxation time goes to infinity, one obtains the exact free streaming solution obtained originally by Denicol et al. For finite relaxation time, we solve the equations numerically and compare to the exact solution of the relaxation-time-approximation Boltzmann equation subject to Gubser flow. Using this as our standard, we find that anisotropic hydrodynamics describes the spatio-temporal evolution of the system better than all currently known dissipative hydrodynamics approaches.

  13. Radiographic interpretation of the appendicular skeleton: A comparison between casualty officers, nurse practitioners and radiographers

    International Nuclear Information System (INIS)

    Coleman, Liz; Piper, Keith

    2009-01-01

    Aim: To assess how accurately and confidently casualty officers, nurse practitioners and radiographers, practicing within the emergency department (ED), recognize and describe radiographic trauma within an image test bank of 20 appendicular radiographs. Method: The participants consisted of 7 casualty officers, 13 nurse practitioners and 18 radiographers. All 20 radiographic examinations selected for the image test bank had been acquired following trauma and included some subtle, yet clinically significant abnormalities. The test bank score (maximum 40 marks), sensitivity and specificity percentages were calculated against an agreed radiological diagnosis (reference standard). Alternative Free-response Receiver Operating Characteristic (AFROC) analysis was used to assess the overall performance of the diagnostic accuracy of these professional groups. The variation in performance between each group was measured using the analysis of variance (ANOVA) test, to identify any statistical significant differences in the performance in interpretation between these groups. The relationship between the participants' perceived image interpretation accuracy during clinical practice and the actual accuracy of their image test bank score was examined using Pearson's Correlation Coefficient (r). Results: The results revealed that the radiographers gained the highest mean test bank score (28.5/40; 71%). This score was statistically higher than the mean test bank scores attained by the participating nurse practitioners (21/40; 53%) and casualty officers (21.5/40; 54%), with p < 0.01 and p = 0.02, respectively. When compared with each other, the scores from these latter groups showed no significant difference (p = 0.91). The mean 'area under the curve' (AUC) value achieved by the radiographers was also significantly higher (p < 0.01) in comparison to the AUC values demonstrated by the nurse practitioners and casualty officers, whose results, when compared, showed no significant

  14. Ergonomic strategies to improve radiographers' posture during mammography activities.

    Science.gov (United States)

    Cernean, Nicolai; Serranheira, Florentino; Gonçalves, Pedro; Sá Dos Reis, Cláudia

    2017-08-01

    To identify alternatives for radiographers' postures while performing mammography that can contribute to reduce the risk of work-related musculoskeletal disorders (WRMSDs). Radiographers' postures to positioning craniocaudal (CC) and mediolateral oblique (MLO) views were simulated without any intervention for three scenarios: radiographer/patient with similar statures, radiographer smaller than patient and radiographer taller than patient. Actions were taken to modify the postures: seated radiographer; patient on a step; seated patient; radiographer on a step. All the postures were analysed using kinovea 0.8.15 software and the angles were measured twice and classified according to European standard EN1005-4: 2005. The non-acceptable angles were measured mainly during MLO positioning when radiographer was taller than the patient: 139° and 120° for arm-flexion and abduction, 72° for trunk and -24° for head/neck-flexion. The introduction of alternative postures (radiographer seated), allowed improvements in posture (60° and 99° for arm flexion and abduction, 14° for trunk and 0° for head/neck flexion), being classified as acceptable. The alternative postures simulated have the potential to reduce the risk of developing WRMSDs when radiographers and patients have different statures. • Radiographers' postures in mammography can contribute to work-related musculoskeletal disorders • Non-acceptable posture was identified for MLO breast positioning (radiographer taller than patient) • Adapting posture to patient biotype reduces the WRMSD risk for radiographers.

  15. Algorithms for boundary detection in radiographic images

    International Nuclear Information System (INIS)

    Gonzaga, Adilson; Franca, Celso Aparecido de

    1996-01-01

    Edge detecting techniques applied to radiographic digital images are discussed. Some algorithms have been implemented and the results are displayed to enhance boundary or hide details. An algorithm applied in a pre processed image with contrast enhanced is proposed and the results are discussed

  16. Comparison of radiographic technique by computer simulation

    International Nuclear Information System (INIS)

    Brochi, M.A.C.; Ghilardi Neto, T.

    1989-01-01

    A computational algorithm to compare radiographic techniques (KVp, mAs and filters) is developed based in the fixation of parameters that defines the images, such as optical density and constrast. Before the experience, the results were used in a radiography of thorax. (author) [pt

  17. Detecting objects in radiographs for homeland security

    Science.gov (United States)

    Prasad, Lakshman; Snyder, Hans

    2005-05-01

    We present a general scheme for segmenting a radiographic image into polygons that correspond to visual features. This decomposition provides a vectorized representation that is a high-level description of the image. The polygons correspond to objects or object parts present in the image. This characterization of radiographs allows the direct application of several shape recognition algorithms to identify objects. In this paper we describe the use of constrained Delaunay triangulations as a uniform foundational tool to achieve multiple visual tasks, namely image segmentation, shape decomposition, and parts-based shape matching. Shape decomposition yields parts that serve as tokens representing local shape characteristics. Parts-based shape matching enables the recognition of objects in the presence of occlusions, which commonly occur in radiographs. The polygonal representation of image features affords the efficient design and application of sophisticated geometric filtering methods to detect large-scale structural properties of objects in images. Finally, the representation of radiographs via polygons results in significant reduction of image file sizes and permits the scalable graphical representation of images, along with annotations of detected objects, in the SVG (scalable vector graphics) format that is proposed by the world wide web consortium (W3C). This is a textual representation that can be compressed and encrypted for efficient and secure transmission of information over wireless channels and on the Internet. In particular, our methods described here provide an algorithmic framework for developing image analysis tools for screening cargo at ports of entry for homeland security.

  18. 21 CFR 1020.31 - Radiographic equipment.

    Science.gov (United States)

    2010-04-01

    ...) RADIOLOGICAL HEALTH PERFORMANCE STANDARDS FOR IONIZING RADIATION EMITTING PRODUCTS § 1020.31 Radiographic... and time, a preset number of pulses, or a preset radiation exposure to the image receptor. (i) Except... exposure of greater than one-half second. Except during panoramic dental radiography, termination of...

  19. Radiographic contrast media, function and future reassessed

    International Nuclear Information System (INIS)

    Sovak, M.

    1988-01-01

    A brief review is given of the use of radiographic contrast media in cholecysto- and cholangiography, central nervous system imaging, urography and angiography. Other aspects briefly discussed are the use of large i.v. doses of contrast media for CT contrast enhancement and the design theory for improved water soluble contrast media. (U.K.)

  20. Radiographic analysis of ameloblastoma: A retrospective study

    Directory of Open Access Journals (Sweden)

    Chandramani More

    2012-01-01

    Conclusion: Radiographs are an important aid for the diagnosis of oral lesions of various types, especially those that involve bone. It is important for the practicing clinicians to know the salient features of ameloblastoma which are peculiar to the local population.

  1. The radiographic investigation of two Egyptian mummies.

    Science.gov (United States)

    Fodor, J; Malott, J C; King, A Y

    1983-01-01

    Radiography is a well-recognized method of nondestructive analysis of art objects and ancient relics. The methods and techniques used in the examination of two ancient Egyptian mummies are presented here. Additionally, the use of radiographic findings to help substantiate alleged historical information and to establish sex, age, and pathology of each specimen is discussed.

  2. Unusual radiographic changes of a gout patient

    International Nuclear Information System (INIS)

    Markota, J.

    2004-01-01

    Background. Gout is a metabolic disorder that results in hyperuricemia and accumulation of uric acid crystals (urats) in tissues, especially joint cartilage. The gouty arthritis presents as acute attacks of arthritis leading eventually to chronic gouty arthritis. In 80% of cases it first occurs in the matatarsophalangeal (MTP) joint of the great toe and is more frequent in male population. Case report. We present a case of unusual radiographic changes accompanying gouty arthritis. A 63 year old female complained about swelling of the first MTP joint on the right, right knee, about stiffness of feet and hands' digits and about backache. First symptoms started to appear 30 years ago. In the time of examination radiographs displayed degenerative changes of the majority of presented joints, bilateral sacroiliitis and osseous ankylosis of both insteps. Microscopic examination showed urate crystals in the samples of the synovial fluid aspirated from the knee. The histological findings of the synovial tissue after the synovectomy were also in favour of gouty arthritis. Conclusions. Radiographs are the most important imaging modality in the diagnostic process of gout. However, radiographic differential diagnosis can be difficult, since the findings overlap with other conditions which cause arthritis and osteoarthritis especially in longstanding gout, elderly patients and females. The diagnosis must be often confirmed with the help of laboratory and histological findings. (author)

  3. Transfer function analysis of radiographic imaging systems

    International Nuclear Information System (INIS)

    Metz, C.E.; Doi, K.

    1979-01-01

    The theoretical and experimental aspects of the techniques of transfer function analysis used in radiographic imaging systems are reviewed. The mathematical principles of transfer function analysis are developed for linear, shift-invariant imaging systems, for the relation between object and image and for the image due to a sinusoidal plane wave object. The other basic mathematical principle discussed is 'Fourier analysis' and its application to an input function. Other aspects of transfer function analysis included are alternative expressions for the 'optical transfer function' of imaging systems and expressions are derived for both serial and parallel transfer image sub-systems. The applications of transfer function analysis to radiographic imaging systems are discussed in relation to the linearisation of the radiographic imaging system, the object, the geometrical unsharpness, the screen-film system unsharpness, other unsharpness effects and finally noise analysis. It is concluded that extensive theoretical, computer simulation and experimental studies have demonstrated that the techniques of transfer function analysis provide an accurate and reliable means for predicting and understanding the effects of various radiographic imaging system components in most practical diagnostic medical imaging situations. (U.K.)

  4. Radiographic Features of Acute Patellar Tendon Rupture.

    Science.gov (United States)

    Fazal, Muhammad Ali; Moonot, Pradeep; Haddad, Fares

    2015-11-01

    The purpose of our study was to assess soft tissue features of acute patellar tendon rupture on lateral knee radiograph that would facilitate early diagnosis. The participants were divided into two groups of 35 patients each. There were 28 men and seven women with a mean age of 46 years in the control group and 26 men and nine women with a mean age of 47 years in the rupture group. The lateral knee radiograph of each patient was evaluated for Insall-Salvati ratio for patella alta, increased density of the infrapatellar fat pad, appearance of the soft tissue margin of the patellar tendon and bony avulsions. In the rupture group there were three consistent soft tissue radiographic features in addition to patellar alta. These were increased density of infrapatellar fat pad; loss of sharp, well-defined linear margins of the patellar tendon and angulated wavy margin of the patellar tendon while in the control group these features were not observed. The soft tissue radiographic features described in the rupture group are consistent and reliable. When coupled with careful clinical assessment, these will aid in early diagnosis and further imaging will be seldom required. © 2015 Chinese Orthopaedic Association and Wiley Publishing Asia Pty Ltd.

  5. Assessment of radiation protection practices among radiographers ...

    African Journals Online (AJOL)

    Application of shielding devices such as gonad shield for protection was neglected mostly in government hospitals. Most x-ray machines were quite old and evidence of quality assurance tests performed on such machines were lacking. Conclusion: Radiographers within Lagos metropolis showed an excellent knowledge of ...

  6. Chest radiographic findings in Human Immunodeficiency Virus ...

    African Journals Online (AJOL)

    This study was carried out to determine findings on chest radiographs in HIV positive/AIDS patients at the University of Benin Teaching Hospital (UBTH) Benin City. All consecutive HIV positive/AIDS patients, managed at the UBTH between 1991 and 2001 were included in the study. Patients had postero-anterior (PA) chest ...

  7. Thoracic radiographic anatomy in goats | Makungu | Tanzania ...

    African Journals Online (AJOL)

    The aim of this study was to describe the normal radiographic anatomy of the thorax of small East African goats as a reference for clinical use. Radiography of the thorax was performed under general anaesthesia in 10 healthy small East African goats. Right lateral (RL), left lateral (LL), dorsoventral (DV) and ventrodorsal ...

  8. Radiographic analysis of pasteurized autologous bone graft

    International Nuclear Information System (INIS)

    Ahmed, Adel Refaat; Manabe, Jun; Kawaguchi, Noriyoshi; Matsumoto, Seiichi; Matsushita, Yasushi

    2003-01-01

    Local malignant bone tumor excision followed by pasteurization and subsequent reimplantation is a unique technique for reconstruction after resection of primary bone sarcomas. The purpose of this investigation was to assess the normal and abnormal long-term radiographic findings of intercalary and osteo-chondral pasteurized bone graft/implant composite. The long-term radiographic findings of pasteurized bone grafts used in reconstruction after resection of bone and soft tissue sarcomas in relation to patients' clinical data were reviewed retrospectively. Thirty-one patients (18 females, 13 males; age range 7-77 years, mean 30 years) who underwent surgery between April 1990 and January 1997 at the authors' institute constituted the material of this study. They were followed up for at least 3 years or until the patient's death (mean 69 months). The International Society of Limb Salvage graft evaluation method that assesses the fusion, resorption, fracture, graft shortening, fixation, subluxation, joint narrowing and subchondral bone was used for evaluation of the radiographs. Twenty-one patients (68%) showed complete incorporation of graft and eight patients (26%) had partial incorporation. The overall radiographic evaluation rate was 81%. Fracture (10%) and infection (16%) were the main complications. No local recurrence was detected. These results indicate that pasteurization of bone is a useful option for reconstruction after resection of malignant bone tumors. (orig.)

  9. The screening pelvic radiograph in pediatric trauma

    International Nuclear Information System (INIS)

    Rees, M.J.; Aickin, R.; Kolbe, A.; Teele, R.L.

    2001-01-01

    Background. Pelvic radiographs are routinely obtained in adult trauma to optimise early management. In adults, pelvic fractures are associated with high early transfusion requirement, high injury severity scores and an increased incidence of other abdominal and thoracic injuries. It is unclear whether this holds true in children. Objective. To determine whether the screening pelvic radiograph is necessary in paediatric trauma. Materials and methods. The notes of all patients who presented after trauma to the Starship Children's Hospital and were triaged to the resuscitation room during 1997 were reviewed. Results of initial radiography were obtained and correlated with later imaging. Results. Our review of 444 injured children seen over a period of 1 year revealed that of 347 children who had screening pelvic radiographs, only 1 had a pelvic fracture. The fracture in this child was clinically apparent and required no specific treatment. Conclusions. The presence of a pelvic fracture is rare in injured children. By omitting screening pelvic radiographs there are potential benefits, including reduced radiation exposure to children and cost savings. Uninterpretable or abnormal clinical examination or haematuria requires further investigation, but routine screening for pelvic fracture is unnecessary. (orig.)

  10. Radiographic analysis of pasteurized autologous bone graft

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Adel Refaat [Department of Orthopedic Surgery, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Kamiikebukuro 1-37-1, Toshima-ku, 170-0012, Tokyo (Japan); Department of Orthopedic Surgery, Alexandria University, Alexandria (Egypt); Manabe, Jun; Kawaguchi, Noriyoshi; Matsumoto, Seiichi; Matsushita, Yasushi [Department of Orthopedic Surgery, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Kamiikebukuro 1-37-1, Toshima-ku, 170-0012, Tokyo (Japan)

    2003-08-01

    Local malignant bone tumor excision followed by pasteurization and subsequent reimplantation is a unique technique for reconstruction after resection of primary bone sarcomas. The purpose of this investigation was to assess the normal and abnormal long-term radiographic findings of intercalary and osteo-chondral pasteurized bone graft/implant composite. The long-term radiographic findings of pasteurized bone grafts used in reconstruction after resection of bone and soft tissue sarcomas in relation to patients' clinical data were reviewed retrospectively. Thirty-one patients (18 females, 13 males; age range 7-77 years, mean 30 years) who underwent surgery between April 1990 and January 1997 at the authors' institute constituted the material of this study. They were followed up for at least 3 years or until the patient's death (mean 69 months). The International Society of Limb Salvage graft evaluation method that assesses the fusion, resorption, fracture, graft shortening, fixation, subluxation, joint narrowing and subchondral bone was used for evaluation of the radiographs. Twenty-one patients (68%) showed complete incorporation of graft and eight patients (26%) had partial incorporation. The overall radiographic evaluation rate was 81%. Fracture (10%) and infection (16%) were the main complications. No local recurrence was detected. These results indicate that pasteurization of bone is a useful option for reconstruction after resection of malignant bone tumors. (orig.)

  11. Correlation Of Radiographic Patterns Of Pulmonary Tuberculosis ...

    African Journals Online (AJOL)

    Patients with higher CD4+ counts often present in \\"classic\\" fashion (upper zone infiltrates cavities) whereas those with low CD4+ counts are more likely to present atypically. The chest radiographic appearances of HIV-seropositive patients presenting with pulmonary tuberculosis (PTB) are diverse, creating difficulty in ...

  12. Effects of rotation radiographic dimensions of metacarpals

    International Nuclear Information System (INIS)

    Armes, F.M.; Horsman, A.; Bentley, H.B.

    1979-01-01

    An experiment is described which shows that small rotations of metacarpals about their long axis produce small systematic changes in the cortical dimensions as measured by radiographic morphometry. The effect is of no significance in cross-sectional studies but is an important source of error in sequential studies. (author)

  13. A theoretical study of hydrodynamic cavitation.

    Science.gov (United States)

    Arrojo, S; Benito, Y

    2008-03-01

    The optimization of hydrodynamic cavitation as an AOP requires identifying the key parameters and studying their effects on the process. Specific simulations of hydrodynamic bubbles reveal that time scales play a major role on the process. Rarefaction/compression periods generate a number of opposing effects which have demonstrated to be quantitatively different from those found in ultrasonic cavitation. Hydrodynamic cavitation can be upscaled and offers an energy efficient way of generating cavitation. On the other hand, the large characteristic time scales hinder bubble collapse and generate a low number of cavitation cycles per unit time. By controlling the pressure pulse through a flexible cavitation chamber design these limitations can be partially compensated. The chemical processes promoted by this technique are also different from those found in ultrasonic cavitation. Properties such as volatility or hydrophobicity determine the potential applicability of HC and therefore have to be taken into account.

  14. Shear viscosity, cavitation and hydrodynamics at LHC

    International Nuclear Information System (INIS)

    Bhatt, Jitesh R.; Mishra, Hiranmaya; Sreekanth, V.

    2011-01-01

    We study evolution of quark-gluon matter in the ultrarelativistic heavy-ion collisions within the frame work of relativistic second-order viscous hydrodynamics. In particular, by using the various prescriptions of a temperature-dependent shear viscosity to the entropy ratio, we show that the hydrodynamic description of the relativistic fluid becomes invalid due to the phenomenon of cavitation. For most of the initial conditions relevant for LHC, the cavitation sets in very early stage. The cavitation in this case is entirely driven by the large values of shear viscosity. Moreover we also demonstrate that the conformal terms used in equations of the relativistic dissipative hydrodynamic can influence the cavitation time.

  15. The RAGE radiation-hydrodynamic code

    Energy Technology Data Exchange (ETDEWEB)

    Gittings, Michael; Clover, Michael; Betlach, Thomas; Byrne, Nelson; Ranta, Dale [Science Applications International Corp. MS A-1, 10260 Campus Point Drive, San Diego, CA 92121 (United States); Weaver, Robert; Coker, Robert; Dendy, Edward; Hueckstaedt, Robert; New, Kim; Oakes, W Rob [Los Alamos National Laboratory, MS T087, PO Box 1663, Los Alamos, NM 87545 (United States); Stefan, Ryan [TaylorMade-adidas Golf, 5545 Fermi Court, Carlsbad, CA 92008-7324 (United States)], E-mail: michael.r.clover@saic.com

    2008-10-01

    We describe RAGE, the 'radiation adaptive grid Eulerian' radiation-hydrodynamics code, including its data structures, its parallelization strategy and performance, its hydrodynamic algorithm(s), its (gray) radiation diffusion algorithm, and some of the considerable amount of verification and validation efforts. The hydrodynamics is a basic Godunov solver, to which we have made significant improvements to increase the advection algorithm's robustness and to converge stiffnesses in the equation of state. Similarly, the radiation transport is a basic gray diffusion, but our treatment of the radiation-material coupling, wherein we converge nonlinearities in a novel manner to allow larger timesteps and more robust behavior, can be applied to any multi-group transport algorithm.

  16. The RAGE radiation-hydrodynamic code

    International Nuclear Information System (INIS)

    Gittings, Michael; Clover, Michael; Betlach, Thomas; Byrne, Nelson; Ranta, Dale; Weaver, Robert; Coker, Robert; Dendy, Edward; Hueckstaedt, Robert; New, Kim; Oakes, W Rob; Stefan, Ryan

    2008-01-01

    We describe RAGE, the 'radiation adaptive grid Eulerian' radiation-hydrodynamics code, including its data structures, its parallelization strategy and performance, its hydrodynamic algorithm(s), its (gray) radiation diffusion algorithm, and some of the considerable amount of verification and validation efforts. The hydrodynamics is a basic Godunov solver, to which we have made significant improvements to increase the advection algorithm's robustness and to converge stiffnesses in the equation of state. Similarly, the radiation transport is a basic gray diffusion, but our treatment of the radiation-material coupling, wherein we converge nonlinearities in a novel manner to allow larger timesteps and more robust behavior, can be applied to any multi-group transport algorithm

  17. Image rejects/retakes--radiographic challenges.

    Science.gov (United States)

    Waaler, D; Hofmann, B

    2010-01-01

    A general held position among radiological personnel prior to digitalisation was that the problem of image rejects/retakes should more or less vanish. However, rejects/retakes still impose several challenges within radiographic imaging; they occupy unnecessary resources, expose patients to unnecessary ionizing radiation and may also indicate suboptimal quality management. The latter is the main objective of this paper, which is based on a survey of international papers published both for screen/film and digital technology. The digital revolution in imaging seems to have reduced the percentage of image rejects/retakes from 10-15 to 3-5 %. The major contribution to the decrease appears to be the dramatic reduction of incorrect exposures. At the same time, rejects/retakes due to lack of operator competence (positioning, etc.) are almost unchanged, or perhaps slightly increased (due to lack of proper technical competence, incorrect organ coding, etc.). However, the causes of rejects/retakes are in many cases defined and reported with reference to radiographers' subjective evaluations. Thus, unless radiographers share common views on image quality and acceptance criteria, objective measurements and assessments of reject/retake rates are challenging tasks. Interestingly, none of the investigated papers employs image quality parameters such as 'too much noise' as categories for rejects/retakes. Surprisingly, no reject/retake analysis seems yet to have been conducted for direct digital radiography departments. An increased percentage of rejects/retakes is related to 'digital skills' of radiographers and therefore points to areas for extended education and training. Furthermore, there is a need to investigate the inter-subjectivity of radiographers' perception of, and attitude towards, both technical and clinical image quality criteria. Finally, there may be a need to validate whether reject/retake rate analysis is such an effective quality indicator as has been asserted.

  18. Image rejects/retakes-radiographic challenges

    International Nuclear Information System (INIS)

    Waaler, D.; Hofmann, B.

    2010-01-01

    A general held position among radiological personnel prior to digitalisation was that the problem of image rejects/retakes should more or less vanish. However, rejects/retakes still impose several challenges within radiographic imaging; they occupy unnecessary resources, expose patients to unnecessary ionizing radiation and may also indicate suboptimal quality management. The latter is the main objective of this paper, which is based on a survey of international papers published both for screen/film and digital technology. The digital revolution in imaging seems to have reduced the percentage of image rejects/retakes from 10-15 to 3-5%. The major contribution to the decrease appears to be the dramatic reduction of incorrect exposures. At the same time, rejects/retakes due to lack of operator competence (positioning, etc.) are almost unchanged, or perhaps slightly increased (due to lack of proper technical competence, incorrect organ coding, etc.). However, the causes of rejects/retakes are in many cases defined and reported with reference to radiographers' subjective evaluations. Thus, unless radiographers share common views on image quality and acceptance criteria, objective measurements and assessments of reject/retake rates are challenging tasks. Interestingly, none of the investigated papers employs image quality parameters such as 'too much noise' as categories for rejects/retakes. Surprisingly, no reject/retake analysis seems yet to have been conducted for direct digital radiography departments. An increased percentage of rejects/retakes is related to 'digital skills' of radiographers and therefore points to areas for extended education and training. Furthermore, there is a need to investigate the inter subjectivity of radiographers' perception of, and attitude towards, both technical and clinical image quality criteria. Finally, there may be a need to validate whether reject/retake rate analysis is such an effective quality indicator as has been asserted

  19. Predicting lower third molar eruption on panoramic radiographs after cephalometric comparison of profile and panoramic radiographs

    DEFF Research Database (Denmark)

    Begtrup, Anders; Grønastøð, Halldis Á; Christensen, Ib Jarle

    2012-01-01

    and to find a simple and reliable method for predicting the eruption of the mandibular third molar by measurements on panoramic radiographs. The material consisted of profile and panoramic radiographs, taken before orthodontic treatment, of 30 males and 23 females (median age 22, range 18-48 years......Previous studies have suggested methods for predicting third molar tooth eruption radiographically. Still, this prediction is associated with uncertainty. The aim of the present study was to elucidate the association between cephalometric measurements on profile and panoramic radiographs...... the length from the ramus to the incisors (olr-id) showed a statistically significant correlation. By combining this length with the mesiodistal width of the lower second molar, the prediction of eruption of the lower third molar was strengthened. A new formula for calculating the probability of eruption...

  20. Impact of hydrodynamic stresses on bacterial flagella

    Science.gov (United States)

    Das, Debasish; Riley, Emily; Lauga, Eric

    2017-11-01

    The locomotion of bacteria powered by helical filaments, such as Escherichia coli, critically involves the generation of flows and hydrodynamic stresses which lead to forces and moments balanced by the moment applied by the bacterial rotary motor (which is embedded in the cell wall) and the deformation of the short flexible hook. In this talk we use numerical computations to accurately compute these hydrodynamic stresses, to show how they critically lead to fluid-structure instabilities at the whole-cell level, and enquire if they can be used to rationalise experimental measurements of bacterial motor torques. ERC Consolidator Grant.

  1. Hydrodynamics of quark-gluon plasmas

    International Nuclear Information System (INIS)

    Blaizot, J.P.

    1986-06-01

    This paper reviews some aspects of the hydrodynamics of quark-gluon plasmas. Various stages of ultra-relativistic heavy ion collisions are described. Several estimates of the maximum energy density expected to be achieved in these collisions are compared. Discontinuities which may be induced in the hydrodynamic flow by a phase transition are described and a convenient numerical method designed to deal with such discontinuous flows is briefly presented. Finally, the correlations between particle transverse momenta and multiplicities are analyzed and one discusses to which extent these correlations could signal the occurrence of a phase transition in heavy ion collisions

  2. FDTD for Hydrodynamic Electron Fluid Maxwell Equations

    Directory of Open Access Journals (Sweden)

    Yingxue Zhao

    2015-05-01

    Full Text Available In this work, we develop a numerical method for solving the three dimensional hydrodynamic electron fluid Maxwell equations that describe the electron gas dynamics driven by an external electromagnetic wave excitation. Our numerical approach is based on the Finite-Difference Time-Domain (FDTD method for solving the Maxwell’s equations and an explicit central finite difference method for solving the hydrodynamic electron fluid equations containing both electron density and current equations. Numerical results show good agreement with the experiment of studying the second-harmonic generation (SHG from metallic split-ring resonator (SRR.

  3. Modeling of laser-driven hydrodynamics experiments

    Science.gov (United States)

    di Stefano, Carlos; Doss, Forrest; Rasmus, Alex; Flippo, Kirk; Desjardins, Tiffany; Merritt, Elizabeth; Kline, John; Hager, Jon; Bradley, Paul

    2017-10-01

    Correct interpretation of hydrodynamics experiments driven by a laser-produced shock depends strongly on an understanding of the time-dependent effect of the irradiation conditions on the flow. In this talk, we discuss the modeling of such experiments using the RAGE radiation-hydrodynamics code. The focus is an instability experiment consisting of a period of relatively-steady shock conditions in which the Richtmyer-Meshkov process dominates, followed by a period of decaying flow conditions, in which the dominant growth process changes to Rayleigh-Taylor instability. The use of a laser model is essential for capturing the transition. also University of Michigan.

  4. Fish stocking density impacts tank hydrodynamics

    DEFF Research Database (Denmark)

    Rasmussen, Michael R.; Lunger, Angela; Laursen, Jesper

    2006-01-01

    The effect of stocking density upon the hydrodynamics of a circular tank, configured in a recirculation system, was investigated. Red drums Sciaenops ocellatus of approximately 140 g wet weight, were stocked at five rates varying from 0 to 12 kg m-3. The impact of the presence of fish upon tank...... hydrodynamics was established using in-tank-based Rhodamine WT fluorometry at a flow rate of 0.23 l s-1 (tank exchange rate of 1.9 h-1). With increasing numbers of animals, curvilinear relationships were observed for dispersion coefficients and tank mixing times. Stocking densities of 3, 6, 9 and 12 kg m-3...

  5. Introduction to physics mechanics, hydrodynamics thermodynamics

    CERN Document Server

    Frauenfelder, P

    2013-01-01

    Introduction of Physics: Mechanics , Hydrodynamics, Thermodynamics covers the principles of matter and its motion through space and time, as well as the related concepts of energy and force. This book is composed of eleven chapters, and begins with an introduction to the basic principles of mechanics, hydrodynamics, and thermodynamics. The subsequent chapters deal with the statics of rigid bodies and the dynamics of particles and rigid bodies. These topics are followed by discussions on elasticity, mechanics of fluids, the basic concept of thermodynamic, kinetic theory, and crystal structure o

  6. Shadowfax: Moving mesh hydrodynamical integration code

    Science.gov (United States)

    Vandenbroucke, Bert

    2016-05-01

    Shadowfax simulates galaxy evolution. Written in object-oriented modular C++, it evolves a mixture of gas, subject to the laws of hydrodynamics and gravity, and any collisionless fluid only subject to gravity, such as cold dark matter or stars. For the hydrodynamical integration, it makes use of a (co-) moving Lagrangian mesh. The code has a 2D and 3D version, contains utility programs to generate initial conditions and visualize simulation snapshots, and its input/output is compatible with a number of other simulation codes, e.g. Gadget2 (ascl:0003.001) and GIZMO (ascl:1410.003).

  7. LAFD: TA-15 DARHT Firefighter Facility Familiarization Tour, OJT 53044, Revision 0.2

    Energy Technology Data Exchange (ETDEWEB)

    Rutherford, Victor Stephen [Los Alamos National Laboratory; Priestley, Terry B. [Los Alamos National Laboratory; Maestas, Marvin Manuel [Los Alamos National Laboratory

    2016-03-17

    The Los Alamos National Laboratory (LANL or the Lab) will conduct familiarization tours for the Los Alamos County Fire Department (LAFD) at the Dual-Axis Radiographic Hydrodynamic Test (DARHT) Facility, TA-15-0312. The purpose of these tours is to orient LAFD firefighters to the DARHT facility layout and hazards. This document provides information and figures to supplement the familiarization tours. The document will be distributed to the trainees at the time of the familiarization tour. A checklist (Attachment A) has also been developed to ensure that all required information is consistently presented to LAFD personnel during the familiarization tours.

  8. Threatened and Endangered Species Habitat Management Plan for Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Hathcock, Charles Dean [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Keller, David Charles [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Thompson, Brent E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-10-16

    Los Alamos National Laboratory’s (LANL) Threatened and Endangered Species Habitat Management Plan (HMP) fulfills a commitment made to the U.S. Department of Energy (DOE) in the “Final Environmental Impact Statement for the Dual-Axis Radiographic Hydrodynamic Test Facility Mitigation Action Plan” (DOE 1996). The HMP received concurrence from the U.S. Fish and Wildlife Service (USFWS) in 1999 (USFWS consultation numbers 2-22-98-I-336 and 2-22-95-I-108). This 2017 update retains the management guidelines from the 1999 HMP for listed species, and updates some descriptive information.

  9. Occupational kneeling and radiographic tibiofemoral and patellofemoral osteoarthritis

    DEFF Research Database (Denmark)

    Rytter, Søren; Egund, Niels; Jensen, Lilli Kirkeskov

    2009-01-01

    ABSTRACT: BACKGROUND: The objective of our study was to evaluate the association between occupational kneeling and compartment specific radiographic tibiofemoral (TF) and patellofemoral (PF) osteoarthritis (OA). METHODS: Questionnaire data and bilateral knee radiographs were obtained in 134 male...

  10. Recognizing the radiographic features of some common bovine foot problems

    International Nuclear Information System (INIS)

    Ebeid, M.; Steiner, A.

    1996-01-01

    Radiographs of an injured or infected bovine foot can be tricky to interpret - the anatomy is complex, and the signs may be subtle. This guide leads you through the classic radiographic features of several common foot conditions

  11. 21 CFR 892.1970 - Radiographic ECG/respirator synchronizer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiographic ECG/respirator synchronizer. 892.1970... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1970 Radiographic ECG/respirator synchronizer. (a) Identification. A radiographic ECG/respirator synchronizer is a device intended to be used to...

  12. Appearance of the mandibular incisive canal on panoramic radiographs

    NARCIS (Netherlands)

    Jacobs, R.; Mraiwa, N.; van Steenberghe, D.; Sanderink, G.C.H.; Quirynen, M.

    2004-01-01

    Panoramic radiographs are routinely used in the dental office for various diagnostic purposes. This study aimed to evaluate the visibility of neurovascular structures in the mandibular interforaminal region on such radiographs. Panoramic radiographs were obtained with a Cranex Tome (Soredex) from

  13. Impact of Hydrodynamics on Oral Biofilm Strength

    NARCIS (Netherlands)

    Paramonova, E.; Kalmykowa, O. J.; van der Mei, H. C.; Busscher, H. J.; Sharma, P. K.

    2009-01-01

    Mechanical removal of oral biofilms is ubiquitously accepted as the best way to prevent caries and periodontal diseases. Removal effectiveness strongly depends on biofilm strength. To investigate the influence of hydrodynamics on oral biofilm strength, we grew single- and multi-species biofilms of

  14. Hydrodynamic states of phonons in insulators

    Directory of Open Access Journals (Sweden)

    S.A. Sokolovsky

    2012-12-01

    Full Text Available The Chapman-Enskog method is generalized for accounting the effect of kinetic modes on hydrodynamic evolution. Hydrodynamic states of phonon system of insulators have been studied in a small drift velocity approximation. For simplicity, the investigation was carried out for crystals of the cubic class symmetry. It has been found that in phonon hydrodynamics, local equilibrium is violated even in the approximation linear in velocity. This is due to the absence of phonon momentum conservation law that leads to a drift velocity relaxation. Phonon hydrodynamic equations which take dissipative processes into account have been obtained. The results were compared with the standard theory based on the local equilibrium validity. Integral equations have been obtained for calculating the objects of the theory (including viscosity and heat conductivity. It has been shown that in low temperature limit, these equations are solvable by iterations. Steady states of the system have been considered and an expression for steady state heat conductivity has been obtained. It coincides with the famous result by Akhiezer in the leading low temperature approximation. It has been established that temperature distribution in the steady state of insulator satisfies a condition of heat source absence.

  15. Magneto-hydrodynamical model for plasma

    Science.gov (United States)

    Liu, Ruikuan; Yang, Jiayan

    2017-10-01

    Based on the Newton's second law and the Maxwell equations for the electromagnetic field, we establish a new 3-D incompressible magneto-hydrodynamics model for the motion of plasma under the standard Coulomb gauge. By using the Galerkin method, we prove the existence of a global weak solution for this new 3-D model.

  16. Statistical analysis of hydrodynamic cavitation events

    Science.gov (United States)

    Gimenez, G.; Sommer, R.

    1980-10-01

    The frequency (number of events per unit time) of pressure pulses produced by hydrodynamic cavitation bubble collapses is investigated using statistical methods. The results indicate that this frequency is distributed according to a normal law, its parameters not being time-evolving.

  17. Filter-Feeding Zoobenthos and Hydrodynamics

    DEFF Research Database (Denmark)

    Riisgård, Hans Ulrik; Larsen, Poul Scheel

    2017-01-01

    interplay between benthic filter feeders and hydrodynamics. Starting from the general concept of grazing potential and typical data on benthic population densities its realization is considered, first at the level of the individual organism through the processes of pumping and trapping of food particles...

  18. does earthworms density really modify soil's hydrodynamic ...

    African Journals Online (AJOL)

    N. Ababsa,, M. Kribaa, D. Addad, L. Tamrabet and M. Baha

    1 mai 2016 ... Journal of Fundamental and Applied Sciences is licensed under a Creative Commons Attribution-NonCommercial 4.0. International License. Libraries Resource Directory. We are listed under Research Associations category. DOES EARTHWORMS DENSITY REALLY MODIFY SOIL'S HYDRODYNAMIC.

  19. PHANTOM: Smoothed particle hydrodynamics and magnetohydrodynamics code

    Science.gov (United States)

    Price, Daniel J.; Wurster, James; Nixon, Chris; Tricco, Terrence S.; Toupin, Stéven; Pettitt, Alex; Chan, Conrad; Laibe, Guillaume; Glover, Simon; Dobbs, Clare; Nealon, Rebecca; Liptai, David; Worpel, Hauke; Bonnerot, Clément; Dipierro, Giovanni; Ragusa, Enrico; Federrath, Christoph; Iaconi, Roberto; Reichardt, Thomas; Forgan, Duncan; Hutchison, Mark; Constantino, Thomas; Ayliffe, Ben; Mentiplay, Daniel; Hirsh, Kieran; Lodato, Giuseppe

    2017-09-01

    Phantom is a smoothed particle hydrodynamics and magnetohydrodynamics code focused on stellar, galactic, planetary, and high energy astrophysics. It is modular, and handles sink particles, self-gravity, two fluid and one fluid dust, ISM chemistry and cooling, physical viscosity, non-ideal MHD, and more. Its modular structure makes it easy to add new physics to the code.

  20. Microflow Cytometers with Integrated Hydrodynamic Focusing

    Directory of Open Access Journals (Sweden)

    Martin Schmidt

    2013-04-01

    Full Text Available This study demonstrates the suitability of microfluidic structures for high throughput blood cell analysis. The microfluidic chips exploit fully integrated hydrodynamic focusing based on two different concepts: Two-stage cascade focusing and spin focusing (vortex principle. The sample—A suspension of micro particles or blood cells—is injected into a sheath fluid streaming at a substantially higher flow rate, which assures positioning of the particles in the center of the flow channel. Particle velocities of a few m/s are achieved as required for high throughput blood cell analysis. The stability of hydrodynamic particle positioning was evaluated by measuring the pulse heights distributions of fluorescence signals from calibration beads. Quantitative assessment based on coefficient of variation for the fluorescence intensity distributions resulted in a value of about 3% determined for the micro-device exploiting cascade hydrodynamic focusing. For the spin focusing approach similar values were achieved for sample flow rates being 1.5 times lower. Our results indicate that the performances of both variants of hydrodynamic focusing suit for blood cell differentiation and counting. The potential of the micro flow cytometer is demonstrated by detecting immunologically labeled CD3 positive and CD4 positive T-lymphocytes in blood.

  1. Numerical methods for hydrodynamic stability problems

    International Nuclear Information System (INIS)

    Fujimura, Kaoru

    1985-11-01

    Numerical methods for solving the Orr-Sommerfeld equation, which is the fundamental equation of the hydrodynamic stability theory for various shear flows, are reviewed and typical numerical results are presented. The methods of asymptotic solution, finite difference methods, initial value methods and expansions in orthogonal functions are compared. (author)

  2. Hydrodynamic relaxations in dissipative particle dynamics

    Science.gov (United States)

    Hansen, J. S.; Greenfield, Michael L.; Dyre, Jeppe C.

    2018-01-01

    This paper studies the dynamics of relaxation phenomena in the standard dissipative particle dynamics (DPD) model [R. D. Groot and P. B. Warren, J. Chem. Phys. 107, 4423 (1997)]. Using fluctuating hydrodynamics as the framework of the investigation, we focus on the collective transverse and longitudinal dynamics. It is shown that classical hydrodynamic theory predicts the transverse dynamics at relatively low temperatures very well when compared to simulation data; however, the theory predictions are, on the same length scale, less accurate for higher temperatures. The agreement with hydrodynamics depends on the definition of the viscosity, and here we find that the transverse dynamics are independent of the dissipative and random shear force contributions to the stress. For high temperatures, the spectrum for the longitudinal dynamics is dominated by the Brillouin peak for large length scales and the relaxation is therefore governed by sound wave propagation and is athermal. This contrasts the results at lower temperatures and small length scale, where the thermal process is clearly present in the spectra. The DPD model, at least qualitatively, re-captures the underlying hydrodynamical mechanisms, and quantitative agreement is excellent at intermediate temperatures for the transverse dynamics.

  3. Hydrodynamic dispersion of microswimmers in suspension

    Science.gov (United States)

    Martin, Matthieu; Rafaï, Salima; Peyla, Philippe

    2014-11-01

    In our laboratory, we study hydrodynamics of suspensions of micro-swimmers. These micro-organisms are unicellular algae Chlamydomonas Rheinhardii which are able to swim by using their flagella. The swimming dynamics of these micro-swimmers can be seen as a random walk, in absence of any kind of interaction. In addition, these algae have the property of being phototactic, i.e. they swim towards the light. Combining this property with a hydrodynamic flow, we were able to reversibly separate algae from the rest of the fluid. But for sufficiently high volume fraction, these active particles interact with each other. We are now interested in how the coupling of hydrodynamic interactions between swimmers and phototaxis can modify the swimming dynamics at the scale of the suspension. To this aim, we conduct experiments in microfluidic devices to study the dispersion of the micro-organisms in a the liquid phase as a function of the volume fraction. We show that the dispersion of an assembly of puller type microswimmers is quantitatively affected by hydrodynamics interactions. Phd student.

  4. Hydrodynamic modelling of hydrostatic magnesium extrusion

    NARCIS (Netherlands)

    Moodij, Ellen; de Rooij, Matthias B.; Schipper, Dirk J.

    2006-01-01

    Wilson’s hydrodynamic model of the hydrostatic extrusion process is extended to meet the geometry found on residual billets. The transition from inlet to work zone of the process is not considered sharp as in the model of Wilson but as a rounded edge, modelled by a parabolic function. It is shown

  5. Dilepton production in schematic causal viscous hydrodynamics

    International Nuclear Information System (INIS)

    Song, Taesoo; Han, Kyong Chol; Ko, Che Ming

    2011-01-01

    Assuming that in the hot dense matter produced in relativistic heavy-ion collisions, the energy density, entropy density, and pressure as well as the azimuthal and space-time rapidity components of the shear tensor are uniform in the direction transversal to the reaction plane, we derive a set of schematic equations from the Isreal-Stewart causal viscous hydrodynamics. These equations are then used to describe the evolution dynamics of relativistic heavy-ion collisions by taking the shear viscosity to entropy density ratio of 1/4π for the initial quark-gluon plasma (QGP) phase and of 10 times this value for the later hadron-gas (HG) phase. Using the production rate evaluated with particle distributions that take into account the viscous effect, we study dilepton production in central heavy-ion collisions. Compared with results from the ideal hydrodynamics, we find that although the dilepton invariant mass spectra from the two approaches are similar, the transverse momentum spectra are significantly enhanced at high transverse momenta by the viscous effect. We also study the transverse momentum dependence of dileptons produced from QGP for a fixed transverse mass, which is essentially absent in the ideal hydrodynamics, and find that this so-called transverse mass scaling is violated in the viscous hydrodynamics, particularly at high transverse momenta.

  6. Hydrodynamic forces on inundated bridge decks

    Science.gov (United States)

    2009-05-01

    The hydrodynamic forces experienced by an inundated bridge deck have great importance in the design of bridges. Specifically, the drag force, lift force, and the moment acting on the bridge deck under various levels of inundation and a range of flow ...

  7. The quantum hydrodynamics of the Sutherland model

    International Nuclear Information System (INIS)

    Stone, Michael; Gutman, Dmitry

    2008-01-01

    We show that the form of the chiral condition found by Abanov et al in the quantum hydrodynamics of the Sutherland model arises because there are two distinct inner products with respect to which the chiral Hamiltonian is Hermitian, but only one with respect to which the full, non-chiral, Hamiltonian is Hermitian

  8. Hydrodynamic impact response, a flexible view

    NARCIS (Netherlands)

    Vredeveldt, A.W.; Hoogeland, M.; Janssen, G.Th.M.

    2001-01-01

    The popularity of high-speed craft is steadily increasing. Until now, much attention has been focussed on the hydrodynamic aspects of these craft. The structural design of these vessels is usually considered in a quasi static sense. However, due to the requirement of light ship structures, fast ship

  9. Universal hydrodynamics of non-conformal branes

    International Nuclear Information System (INIS)

    Kanitscheider, Ingmar; Skenderis, Kostas

    2009-01-01

    We examine the hydrodynamic limit of non-conformal branes using the recently developed precise holographic dictionary. We first streamline the discussion of holography for backgrounds that asymptote locally to non-conformal brane solutions by showing that all such solutions can be obtained from higher dimensional asymptotically locally AdS solutions by suitable dimensional reduction and continuation in the dimension. As a consequence, many holographic results for such backgrounds follow from the corresponding results of the Asymptotically AdS case. In particular, the hydrodynamics of non-conformal branes is fully determined in terms of conformal hydrodynamics. Using previous results on the latter we predict the form of the non-conformal hydrodynamic stress tensor to second order in derivatives. Furthermore we show that the ratio between bulk and shear viscosity is fixed by the generalized conformal structure to be ζ/η = 2(1/(d-1)-c s 2 ), where c s is the speed of sound in the fluid.

  10. Detailed simulation of morphodynamics : 1. Hydrodynamic model

    NARCIS (Netherlands)

    Nabi, M.; De Vriend, H.J.; Mosselman, E.; Sloff, C.J.; Shimizu, Y.

    2012-01-01

    We present a three-dimensional high-resolution hydrodynamic model for unsteady incompressible flow over an evolving bed topography. This is achieved by using a multilevel Cartesian grid technique that allows the grid to be refined in high-gradient regions and in the vicinity of the river bed. The

  11. Radiographic cup anteversion measurement corrected from pelvic tilt.

    Science.gov (United States)

    Wang, Liao; Thoreson, Andrew R; Trousdale, Robert T; Morrey, Bernard F; Dai, Kerong; An, Kai-Nan

    2017-11-01

    The purpose of this study was to develop a novel technique to improve the accuracy of radiographic cup anteversion measurement by correcting the influence of pelvic tilt. Ninety virtual total hip arthroplasties were simulated from computed tomography data of 6 patients with 15 predetermined cup orientations. For each simulated implantation, anteroposterior (AP) virtual pelvic radiographs were generated for 11 predetermined pelvic tilts. A linear regression model was created to capture the relationship between radiographic cup anteversion angle error measured on AP pelvic radiographs and pelvic tilt. Overall, nine hundred and ninety virtual AP pelvic radiographs were measured, and 90 linear regression models were created. Pearson's correlation analyses confirmed a strong correlation between the errors of conventional radiographic cup anteversion angle measured on AP pelvic radiographs and the magnitude of pelvic tilt (P cup anteversion angle from the influence of pelvic tilt. The current method proposes to measure the pelvic tilt on a lateral radiograph, and to use it as a correction for the radiographic cup anteversion measurement on an AP pelvic radiograph. Thus, both AP and lateral pelvic radiographs are required for the measurement of pelvic posture-integrated cup anteversion. Compared with conventional radiographic cup anteversion, the errors of pelvic posture-integrated radiographic cup anteversion were reduced from 10.03 (SD = 5.13) degrees to 2.53 (SD = 1.33) degrees. Pelvic posture-integrated cup anteversion measurement improves the accuracy of radiographic cup anteversion measurement, which shows the potential of further clarifying the etiology of postoperative instability based on planar radiographs. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

  12. Digital radiographic assessment of coronary flow reserve

    International Nuclear Information System (INIS)

    Vogel, R.A.

    1985-01-01

    A method for measuring relative changes in regional blood flow using digital radiographic enhancement of selective coronary arteriography. Coronary flow reserve is measured in individual arterial distributions using the washin ratio of contrast appearance time under baseline and hyperemic conditions. Information is quantitatively presented in functional (parametric) image format. These images, termed contrast medium appearance pictures (CMAP), depict the transit of contrast through the arterial, myocardial and early venous stages. This process can be divided into three general phases: data acquisition, CMAP formation and CMAP analysis. The technique has evolved over its development period from a cine film-based technology which required substantial processing time to a real-time digital radiographic technique

  13. RADIOGRAPHIC EXAMINATION OF TEMPOROMANDIBULAR DISORDERS IN CHILDREN

    Directory of Open Access Journals (Sweden)

    Heru Suryonegoro

    2015-06-01

    Full Text Available The temporomandibular joint has a very important role in the stomatognathic system. Its main function is for the opening and closing movement, mastication, and speech. It is located anterior to the ear. The temporomandibular joint connects maxilla and mandible through the articular fossa, hence the slightest change that happens would cause serious matters such as pain, exiting, speech disorder, difficulty in opening and closing movement, headache, and even trismus. In a child or an adolescent, the symptoms are often vague; everything is interpreted as “pain”. This is probably why temporomandibular disorder are often undetected by dentists. Therefore, patience and accuracy is needed to determine the actual disorder through means of clinical and radiographic examination. The radiographic examination suitable for child is the transcranial projection. This projection is believed to be more accurate amongst other projection for child patients.

  14. Radiographic examination of the equine stifle

    International Nuclear Information System (INIS)

    Denoix, J.M.

    1986-01-01

    A radiographic technique is described for the equine stifle joint with the horse in the standing position or under general anaesthesia. The method with the animal anaesthetised in the dorsal recumbency and the leg extended was preferred because it gave greater flexibility with a better range of views and greatly reduced the safety hazards. In the standing position a useful practical tip for the lateral view was to raise and extent the limb caudally. This provides some flexion and ventral movement of the stifle allowing improved access for the cassette, a more accurate lateral view of the joint and a reduction in exposure. Some of the features of radiographic anatomy, from birth to adulthood, of this rather complex joint are described to form a basis for radiological interpretation in cases of suspected stifle lameness

  15. The radiographic features of familial expansile osteolysis

    International Nuclear Information System (INIS)

    Crone, M.D.; Wallace, R.G.H.

    1990-01-01

    The radiographic features of a unique autosomal dominant bone dysplasia are presented. The features are classified as generalised and/or focal. Generalised features are either altered trabecular pattern or modelling abnormalities. Focal features comprise lytic areas which progressively enlarge, producing expansion of the bone and eventual disintegration due to fibrous and finally fatty replacement of the normal medulla. Almost 90% of these lesions occur in the appendicular skeleton. Clinically, hearing loss is the earliest manifestation of the disease, presenting sometimes as early as 4 years of age. Apical and cervical resorption of teeth is extremely common, resulting in premature loss of teeth. Radiologically, the differential diagnosis refers to Paget's disease, polyostotic fibrous dysplasia, and osteofibrous dysplasia. The progressive destruction of the bone is similar to massive osteolysis (Gorham's disease). The radiographic features in combination with the histopathology render the condition unique. (orig.)

  16. An Applied Image Processing for Radiographic Testing

    International Nuclear Information System (INIS)

    Ratchason, Surasak; Tuammee, Sopida; Srisroal Anusara

    2005-10-01

    An applied image processing for radiographic testing (RT) is desirable because it decreases time-consuming, decreases the cost of inspection process that need the experienced workers, and improves the inspection quality. This paper presents the primary study of image processing for RT-films that is the welding-film. The proposed approach to determine the defects on weld-images. The BMP image-files are opened and developed by computer program that using Borland C ++ . The software has five main methods that are Histogram, Contrast Enhancement, Edge Detection, Image Segmentation and Image Restoration. Each the main method has the several sub method that are the selected options. The results showed that the effective software can detect defects and the varied method suit for the different radiographic images. Furthermore, improving images are better when two methods are incorporated

  17. Radiographic and pathologic observations of eosinophilic gastroenteritis

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Lae Won [Busan Nationa University College of Medicine, Busan (Korea, Republic of); Hong, Sook Hee; Lee, Jung Dal [Busan Gospel Hospital, Busan (Korea, Republic of)

    1974-10-15

    This report presents two cases with eosinophilic gastroenteritis in detail. The radiographic and pathologic features of eosinophilic gastroenteritis are summarized with emphasis on the differential diagnostic features. Radiographic eosinophilic gastritis should be differentiated from gastric carcinoma and lymphoma, and eosinophilic enteritis from intestinal tuberculosis and intussusception of the small bowel in Korea where these entities are prevent. Eosinophilic gastroenteritis is pathologically characterized by diffuse infiltration of the submucosa and muscle coats with eosinophilic in conjunction with hypertrophy of individual muscle fibers. This leads to thickening of the gastrointestinal wall resulting in narrowing and obstruction of the lumen. Eosinophilic venulitis is another characteristic feature which is helpful for differentiation this entity from a parasitic infection.

  18. The radiographic examination of the colon

    International Nuclear Information System (INIS)

    Hendrix, T.R.; Saba, G.P. II.

    1980-01-01

    To provide medical and scientific background on certain selected technologies generally considered to be of particular significance, the National Center for Health Care Technology commissioned a series of overview papers, one of which is entitled 'The Radiographic Examination of the Colon.' These overviews are likely to be of most immediate interest to clinicians and biomedical scientists; they also may provide valuable background for assessments undertaken by the Center and for exploring the broad societal implications of health care technologies. Barium enema is the most available and widely used technique for examining the colon. It is often a routine part of the gastrointestinal work-up regardless of the suspected basis, anatomical or functional, of the patient's symptoms. Indeed, common practice is not to entertain a diagnosis of functional disorder before excluding all reasonable possibility of an anatomical abnormality. Barium enema is one of the most frequently ordered radiographic examinations

  19. MINAC, portable high energy radiographic inspection system

    International Nuclear Information System (INIS)

    Lapides, M.E.; Schonberg, R.

    1985-01-01

    MINAC, a portable, high energy radiographic source (1) was recognized as a desired inspection device for nuclear generation plants during EPRI-sponsored studies of the late 1970s and rapidly transitioned from proof-of-principle (1978-1980) to field-proven hardware (1981-present date). The equipment has completed its second generation of configuration development (SHRINKAC), that has recently been used in the field for detection of pipe cracks. Important auxiliaries for image data processing and real-time, thick section radiography have been demonstrated in both laboratory and field situations. Finally, a 6 MeV accelerator alternate is in bench test. These significant developments have, and are expected to continue to upgrade the utility of radiographic inspection in power plant practice. This paper describes the development and experience with this modular system during the last three years

  20. Radiographic and pathologic observations of eosinophilic gastroenteritis

    International Nuclear Information System (INIS)

    Jung, Lae Won; Hong, Sook Hee; Lee, Jung Dal

    1974-01-01

    This report presents two cases with eosinophilic gastroenteritis in detail. The radiographic and pathologic features of eosinophilic gastroenteritis are summarized with emphasis on the differential diagnostic features. Radiographic eosinophilic gastritis should be differentiated from gastric carcinoma and lymphoma, and eosinophilic enteritis from intestinal tuberculosis and intussusception of the small bowel in Korea where these entities are prevent. Eosinophilic gastroenteritis is pathologically characterized by diffuse infiltration of the submucosa and muscle coats with eosinophilic in conjunction with hypertrophy of individual muscle fibers. This leads to thickening of the gastrointestinal wall resulting in narrowing and obstruction of the lumen. Eosinophilic venulitis is another characteristic feature which is helpful for differentiation this entity from a parasitic infection

  1. Black Lung Benefits Act: standards for chest radiographs. Final rule.

    Science.gov (United States)

    2014-04-17

    Physicians and adjudicators use chest radiographs (X-rays) as a tool in evaluating whether a coal miner suffers from pneumoconiosis (black lung disease). Accordingly, the Department's regulations implementing the Black Lung Benefits Act allow the submission of radiographs in connection with benefit claims and set out quality standards for administering and interpreting film-based chest radiographs. This final rule updates the Department's existing film-radiograph standards and provides parallel standards for digital radiographs. This rule also updates outdated terminology and removes certain obsolete provisions.

  2. Chest radiographic manifestations of scrub typhus.

    Science.gov (United States)

    Abhilash, Kpp; Mannam, P R; Rajendran, K; John, R A; Ramasami, P

    2016-01-01

    Respiratory system involvement in scrub typhus is seen in 20-72% of patients. In endemic areas, good understanding and familiarity with the various radiologic findings of scrub typhus are essential in identifying pulmonary complications. Patients admitted to a tertiary care center with scrub typhus between October 2012 and September 2013 and had a chest X ray done were included in the analysis. Details and radiographic findings were noted and factors associated with abnormal X-rays were analyzed. The study cohort contained 398 patients. Common presenting complaints included fever (100%), generalized myalgia (83%), headache (65%), dyspnea (54%), cough (24.3%), and altered sensorium (14%). Almost half of the patients (49.4%) had normal chest radiographs. Common radiological pulmonary abnormalities included pleural effusion (14.6%), acute respiratory distress syndrome (14%), airspace opacity (10.5%), reticulonodular opacities (10.3%), peribronchial thickening (5.8%), and pulmonary edema (2%). Cardiomegaly was noted in 3.5% of patients. Breathlessness, presence of an eschar, platelet counts of 2 mg/dL had the highest odds of having an abnormal chest radiograph. Patients with an abnormal chest X-ray had a higher requirement of noninvasive ventilation (odds ratio [OR]: 13.98; 95% confidence interval CI: 5.89-33.16), invasive ventilation (OR: 18.07; 95% CI: 6.42-50.88), inotropes (OR: 8.76; 95% CI: 4.35-17.62), higher involvement of other organ systems, longer duration of hospital stay (3.18 ± 3 vs. 7.27 ± 5.58 days; Pscrub typhus have abnormal chest radiographs. Chest radiography should be included as part of basic evaluation at presentation in patients with scrub typhus, especially in those with breathlessness, eschar, jaundice, and severe thrombocytopenia.

  3. The equine flexed lateral fetlock radiographic view

    International Nuclear Information System (INIS)

    Dyer, L.L.

    1993-01-01

    Recommendations for obtaining the flexed lateral radiographic view of the equine fetlock are provided. By tilting the X-ray tube in a 10-degrees dorsal direction, the angle of the flexed lateral fetlock joint is matched. While this view will not be effective on all horses, utilizing the flexed view aids in evaluating those horses that present an abnormal conformation when the fetlock joint is flexed

  4. Video enhancement of dental radiographic films

    International Nuclear Information System (INIS)

    Van Dis, M.L.; Beck, F.M.; Miles, D.A.

    1989-01-01

    A prototype video image display system, a real-time analog enhancer (RAE), was compared to conventional viewing conditions with the use of nonscreen dental films. When medium optical density films were evaluated, there was no significant difference in the number of radiographic details detected. Conventional viewing conditions allowed perception of more details when dark films were evaluated; however, the RAE unit allowed the perception of more details when light films were viewed

  5. Radiographic investigations during medico-legal autopsies

    Energy Technology Data Exchange (ETDEWEB)

    Bratzke, H.; Schneider, V.; Dietz, W.

    1982-04-01

    During the last 13 years (1968-1980), 427 radiographic examinations were carried out during the course of medico-legal autopsies at the Institute of Forensic Medicine at the Free University of Berlin. Important problems were the demonstration of retained foreign bodies resulting from shooting, stabbing or blunt trauma, bone injuries, identification, and the question of life in neonates. An historical survey is given and 12 cases with special forensic problems are illustrated and discussed, and further means of investigations are described.

  6. An improved method for simulating radiographs

    International Nuclear Information System (INIS)

    Laguna, G.W.

    1986-01-01

    The parameters involved in generating actual radiographs and what can and cannot be modeled are examined in this report. Using the spectral distribution of the radiation source and the mass absorption curve for the material comprising the part to be modeled, the actual amount of radiation that would pass through the part and reach the film is determined. This method increases confidence in the results of the simulation and enables the modeling of parts made of multiple materials

  7. Intraligamentary--intraosseous anesthesia. A radiographic demonstration.

    Science.gov (United States)

    Garfunkel, A A; Kaufman, E; Marmary, Y; Galili, D

    1983-10-01

    Intraligamentary dental anesthesia has become a widely accepted technique. The periodontal ligament seems to provide easy access to the tooth apex. In the present study, radiopaque material was injected into baboon monkeys. Serial radiographs during incremental injections showed clouding of the crestal bone. The material was seen gradually advancing through the alveolar bone crest, apically. The spread was noticed through the marrow spaces, unexpectedly avoiding the PDL route.

  8. A radiographic anthology of vertebral names.

    Science.gov (United States)

    Yochum, T R; Hartley, B; Thomas, D P; Guebert, G M

    1985-06-01

    There are many conditions of the spine to which various authors have applied descriptive names. This paper, an extensive review of the literature, provides the first complete source for such named vertebrae. Included are 88 names covering all categories of bone disease. A brief description of the radiographic appearance and its pathogenesis is provided for each, along with a consideration of the disease processes which may produce the appearance.

  9. Radiographic imaging of the canine intercondylar fossa

    International Nuclear Information System (INIS)

    Montgomery, R.D.; Fitch, R.B.; Hathcock, J.T.; LaPrade, R.F.; Wilson, M.E.; Garrett, P.D.

    1996-01-01

    The intercondylar fossa is believed to play an important role in the pathology of cranial cruciate ligament rupture and therefore has received considerable attention in the last decade. Accurate radiographic imaging of the intercondylar fossa requires that the central x-ray beam pass through the center of the intercondylar “tunnel”. The anatomy of the canine intercondylar fossa is similar to humans, however, the orientations of the intercondylar fossa's differ. Consequently, the positioning techniques described for humans are not appropriate for the dog. To pass through the center of the dog, intercondylar fossa, the central x-ray beam should be 12° (S.D. 1.7°) caudal from the femoral diaphysis in the sagittal plane and obliqued caudolateral to craniomedial 7° (S.D. 0.60°) (caudo78°proximo7° lateralcraniodistomedial oblique). Cross table positioning was used with the hip flexed and the radiograph cassette placed on the cranial surface of the stifle. However, superimposition of the tuber ischii and soft tissues caudal to the femur made 15° to 20° the best angle obtainable. There was not a significant difference (p = 0.17) in the notch width index between a 12° versus 20° angle of the central x-ray beam caudal to the femoral diaphysis, both with 7° of external rotation of the stifle. The notch width index of 0.252 obtained from radiographic measurements was not significantly different from measurements obtained grossly of 0.254 (n = 26; p = 0.69). Failure to oblique the central x-ray beam caused a significant (p = 0.0008) decrease in the apparent fossa width radiographically

  10. The Society of Radiographers' research strategy

    International Nuclear Information System (INIS)

    Reeves, Pauline; Wright, Caroline; Shelley, Susan; Williams, Pat

    2004-01-01

    A research strategy for the Radiography (London 1995) profession was approved by the Council of the Society and College of Radiographers at the end of 2001.This paper discusses the formulation of that strategy, including the factors that lay behind its development. The recommendations of the strategy are then addressed one by one, together with a review as to their implementation by the College's Research Group

  11. Large-Scale Description of Interacting One-Dimensional Bose Gases: Generalized Hydrodynamics Supersedes Conventional Hydrodynamics

    Science.gov (United States)

    Doyon, Benjamin; Dubail, Jérôme; Konik, Robert; Yoshimura, Takato

    2017-11-01

    The theory of generalized hydrodynamics (GHD) was recently developed as a new tool for the study of inhomogeneous time evolution in many-body interacting systems with infinitely many conserved charges. In this Letter, we show that it supersedes the widely used conventional hydrodynamics (CHD) of one-dimensional Bose gases. We illustrate this by studying "nonlinear sound waves" emanating from initial density accumulations in the Lieb-Liniger model. We show that, at zero temperature and in the absence of shocks, GHD reduces to CHD, thus for the first time justifying its use from purely hydrodynamic principles. We show that sharp profiles, which appear in finite times in CHD, immediately dissolve into a higher hierarchy of reductions of GHD, with no sustained shock. CHD thereon fails to capture the correct hydrodynamics. We establish the correct hydrodynamic equations, which are finite-dimensional reductions of GHD characterized by multiple, disjoint Fermi seas. We further verify that at nonzero temperature, CHD fails at all nonzero times. Finally, we numerically confirm the emergence of hydrodynamics at zero temperature by comparing its predictions with a full quantum simulation performed using the NRG-TSA-abacus algorithm. The analysis is performed in the full interaction range, and is not restricted to either weak- or strong-repulsion regimes.

  12. Data acquisition system for radiographic imaging

    International Nuclear Information System (INIS)

    Lanza, R.C.; Votano, J.R.; Russ, T.

    1992-01-01

    This patent describes a continuous data acquisition system for radiographic imaging without interrupting acquisition activity the acquisition system. It comprises at least two memory means for storing radiographic data from a radiation detector wherein each of the memory means having a plurality of addressable memory locations and each of the memory means are such that the locations of the memory means correspond to spatial locations in the radiation detector; logic control means for sensing radiographic data transmitted by the radiation detector, for selecting one of the memory means for storage of the data, for transferring data to the selected memory means, and for switching form one memory means to another memory means according to a predefined schedule and according to memory capacity level, the logic control means further comprising a logic device which receives data and increments the contents of locations in a memory means in response to such data; and interface control means for reading data from one or the other memory means when such memory means is not actively acquiring data such that data can be acquired continuously by the system

  13. Nosocomial Legionnaires’ Disease: Clinical and Radiographic Patterns

    Directory of Open Access Journals (Sweden)

    Thomas J Marrie

    1992-01-01

    Full Text Available From 1981 to 1991, 55 patients (33 males, 22 females, mean age 58.6 years with nosocomial Legionnaires’ disease were studied. The mortality rate was 64%. One-half of the patients developed nosocomial Legionnaires’ disease within three weeks of admission. A surprising clinical feature was the low rate of findings of consolidation on physical examination, despite the fact that 52% of patients had this finding on chest radiograph. More than one-half of patients had pre-existing lung disease, rendering a radiographic diagnosis of pneumonia due to Legionella pneumophila impossible in 16% of cases despite microbiological confirmation. Nineteen per cent of patients who had blood cultures done had a pathogen other than L pneumophila isolated, suggesting dual infection in at least some of the patients. When the clinical and radiographic findings were combined it was noted that 40% of patients had one of three patterns suggestive of nosocomial Legionnaires’ disease: rapidly progressive pneumonia, lobar opacity and multiple peripheral opacities. However, in 60% of patients there were no distinctive features.

  14. Artificial intelligence for analyzing orthopedic trauma radiographs.

    Science.gov (United States)

    Olczak, Jakub; Fahlberg, Niklas; Maki, Atsuto; Razavian, Ali Sharif; Jilert, Anthony; Stark, André; Sköldenberg, Olof; Gordon, Max

    2017-12-01

    Background and purpose - Recent advances in artificial intelligence (deep learning) have shown remarkable performance in classifying non-medical images, and the technology is believed to be the next technological revolution. So far it has never been applied in an orthopedic setting, and in this study we sought to determine the feasibility of using deep learning for skeletal radiographs. Methods - We extracted 256,000 wrist, hand, and ankle radiographs from Danderyd's Hospital and identified 4 classes: fracture, laterality, body part, and exam view. We then selected 5 openly available deep learning networks that were adapted for these images. The most accurate network was benchmarked against a gold standard for fractures. We furthermore compared the network's performance with 2 senior orthopedic surgeons who reviewed images at the same resolution as the network. Results - All networks exhibited an accuracy of at least 90% when identifying laterality, body part, and exam view. The final accuracy for fractures was estimated at 83% for the best performing network. The network performed similarly to senior orthopedic surgeons when presented with images at the same resolution as the network. The 2 reviewer Cohen's kappa under these conditions was 0.76. Interpretation - This study supports the use for orthopedic radiographs of artificial intelligence, which can perform at a human level. While current implementation lacks important features that surgeons require, e.g. risk of dislocation, classifications, measurements, and combining multiple exam views, these problems have technical solutions that are waiting to be implemented for orthopedics.

  15. Accuracy of radiographer reporting of paediatric brain CT

    International Nuclear Information System (INIS)

    Brandt, Andrew; Louw, Brand; Dekker, Gerrit; Andronikou, Savvas; Wieselthaler, Nicki; Kilborn, Tracy; Bertelsman, Jessica; Dreyer, Catherine

    2007-01-01

    Radiographer reporting has been studied for plain films and for ultrasonography, but not in paediatric brain CT in the emergency setting. To study the accuracy of radiographer reporting in paediatric brain CT. We prospectively collected 100 paediatric brain CT examinations. Films were read from hard copies using a prescribed tick sheet. Radiographers with 12 years' and 3 years' experience, respectively, were blinded to the history and were not trained in diagnostic film interpretation. The radiographers' results were compared with those of a consultant radiologist. Three categories were defined: abnormal scans, significant abnormalities and insignificant abnormalities. Both radiographers had an accuracy of 89.5% in reading a scan correctly as abnormal, and radiographer 1 had a sensitivity of 87.8% and radiographer 2 a sensitivity of 96%. Radiographer 1 had an accuracy in detecting a significant abnormality of 75% and radiographer 2 an accuracy of 48.6%, and the sensitivities for this category were 61.6% and 52.9%, respectively. Results for detecting the insignificant abnormalities were poorer. Selected radiographers could play an effective screening role, but lacking the sensitivity required for detecting significant abnormality, they could not be the final diagnostician. We recommend that the study be repeated after both radiographers have received formal training in interpretation of paediatric brain CT. (orig.)

  16. Modelling hydrodynamic parameters to predict flow assisted corrosion

    International Nuclear Information System (INIS)

    Poulson, B.; Greenwell, B.; Chexal, B.; Horowitz, J.

    1992-01-01

    During the past 15 years, flow assisted corrosion has been a worldwide problem in the power generating industry. The phenomena is complex and depends on environment, material composition, and hydrodynamic factors. Recently, modeling of flow assisted corrosion has become a subject of great importance. A key part of this effort is modeling the hydrodynamic aspects of this issue. This paper examines which hydrodynamic parameter should be used to correlate the occurrence and rate of flow assisted corrosion with physically meaningful parameters, discusses ways of measuring the relevant hydrodynamic parameter, and describes how the hydrodynamic data is incorporated into the predictive model

  17. Hydrodynamic Cavitation-Assisted Synthesis of Nanocalcite

    Directory of Open Access Journals (Sweden)

    Shirish H. Sonawane

    2010-01-01

    Full Text Available A systematic study was made on the synthesis of nanocalcite using a hydrodynamic cavitation reactor. The effects of various parameters such as diameter and geometry of orifice, CO2 flow rate, and Ca(OH2 concentration were investigated. It was observed that the orifice diameter and its geometry had significant effect on the carbonation process. The reaction rate was significantly faster than that observed in a conventional carbonation process. The particle size was significantly affected by the reactor geometry. The results showed that an orifice with 5 holes of 1 mm size resulted in the particle size reduction to 37 nm. The experimental investigation reveals that hydrodynamic cavitation may be more energy efficient.

  18. Application of hydrodynamics to heavy ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Felsberger, Lukas

    2014-12-02

    The Bjorken model is a simple tool for making rough predictions of the hydrodynamic evolution of the thermalized matter created in a heavy ion collision. The advantage of the model clearly lies in its simplicity, rather than accuracy. As it is still used for making rough estimations 'by hand', in this thesis, I investigate in which cases the Bjorken model gives useful results and in which it is not recommended. For central collisions, I show which critical size the nuclei should have so that the Bjorken model can be applied. For non-central collisions, I demonstrate that using Glauber initial conditions combined with the Bjorken evolution, leads to reasonable results up to large impact parameters. Finally, I study the case of a non-ideal (viscous) description of the thermalized matter which leads to strongly differing results if first- or second-order hydrodynamics is applied.

  19. Hyperbolic metamaterial lens with hydrodynamic nonlocal response

    DEFF Research Database (Denmark)

    Yan, Wei; Mortensen, N. Asger; Wubs, Martijn

    2013-01-01

    We investigate the effects of hydrodynamic nonlocal response in hyperbolic metamaterials (HMMs), focusing on the experimentally realizable parameter regime where unit cells are much smaller than an optical wavelength but much larger than the wavelengths of the longitudinal pressure waves...... of the free-electron plasma in the metal constituents. We derive the nonlocal corrections to the effective material parameters analytically, and illustrate the noticeable nonlocal effects on the dispersion curves numerically. As an application, we find that the focusing characteristics of a HMM lens...... in the local-response approximation and in the hydrodynamic Drude model can differ considerably. In particular, the optimal frequency for imaging in the nonlocal theory is blueshifted with respect to that in the local theory. Thus, to detect whether nonlocal response is at work in a hyperbolic metamaterial, we...

  20. Application of hydrodynamics to heavy ion collisions

    International Nuclear Information System (INIS)

    Felsberger, Lukas

    2014-01-01

    The Bjorken model is a simple tool for making rough predictions of the hydrodynamic evolution of the thermalized matter created in a heavy ion collision. The advantage of the model clearly lies in its simplicity, rather than accuracy. As it is still used for making rough estimations 'by hand', in this thesis, I investigate in which cases the Bjorken model gives useful results and in which it is not recommended. For central collisions, I show which critical size the nuclei should have so that the Bjorken model can be applied. For non-central collisions, I demonstrate that using Glauber initial conditions combined with the Bjorken evolution, leads to reasonable results up to large impact parameters. Finally, I study the case of a non-ideal (viscous) description of the thermalized matter which leads to strongly differing results if first- or second-order hydrodynamics is applied.

  1. Hydrodynamic interaction between bacteria and passive sphere

    Science.gov (United States)

    Zhang, Bokai; Ding, Yang; Xu, Xinliang

    2017-11-01

    Understanding hydrodynamic interaction between bacteria and passive sphere is important for identifying rheological properties of bacterial and colloidal suspension. Over the past few years, scientists mainly focused on bacterial influences on tracer particle diffusion or hydrodynamic capture of a bacteria around stationary boundary. Here, we use superposition of singularities and regularized method to study changes in bacterial swimming velocity and passive sphere diffusion, simultaneously. On this basis, we present a simple two-bead model that gives a unified interpretation of passive sphere diffusion and bacterial swimming. The model attributes both variation of passive sphere diffusion and changes of speed of bacteria to an effective mobility. Using the effective mobility of bacterial head and tail as an input function, the calculations are consistent with simulation results at a broad range of tracer diameters, incident angles and bacterial shapes.

  2. Granular Gases: Probing the Boundaries of Hydrodynamics

    International Nuclear Information System (INIS)

    Goldhirsch, I.

    1999-01-01

    The dissipative nature of the particle interactions in granular systems renders granular gases mesoscopic and bearing some similarities to regular gases in the ''continuum transition regime'' where shear rates and/or thermal gradients are very large). The following properties of granular gases support the above claim: (i). Mean free times are of the same order as macroscopic time scales (inverse shear rates); (ii). Mean free paths can be macroscopic and comparable to the system's dimensions; (iii). Typical flows are supersonic; (iv). Shear rates are typically ''large''; (v). Stress fields are scale (resolution) dependent; (vi). Burnett and super-Burnett corrections to both the constitutive relations and the boundary conditions are of importance; (vii). Single particle distribution functions can be far from Gaussian. It is concluded that while hydrodynamic descriptions of granular gases are relevant, they are probing the boundaries of applicability of hydrodynamics and perhaps slightly beyond

  3. The role of Weyl symmetry in hydrodynamics

    Science.gov (United States)

    Diles, Saulo

    2018-04-01

    This article is dedicated to the analysis of Weyl symmetry in the context of relativistic hydrodynamics. Here is discussed how this symmetry is properly implemented using the prescription of minimal coupling: ∂ → ∂ + ωA. It is shown that this prescription has no problem to deal with curvature since it gives the correct expressions for the commutator of covariant derivatives. In hydrodynamics, Weyl gauge connection emerges from the degrees of freedom of the fluid: it is a combination of the expansion and entropy gradient. The remaining degrees of freedom, shear, vorticity and the metric tensor, are see in this context as charged fields under the Weyl gauge connection. The gauge nature of the connection provides natural dynamics to it via equations of motion analogous to the Maxwell equations for electromagnetism. As a consequence, a charge for the Weyl connection is defined and the notion of local charge is analyzed generating the conservation law for the Weyl charge.

  4. Heat capacity of liquids: A hydrodynamic approach

    Directory of Open Access Journals (Sweden)

    T. Bryk

    2015-03-01

    Full Text Available We study autocorrelation functions of energy, heat and entropy densities obtained by molecular dynamics simulations of supercritical Ar and compare them with the predictions of the hydrodynamic theory. It is shown that the predicted by the hydrodynamic theory single-exponential shape of the entropy density autocorrelation functions is perfectly reproduced for small wave numbers by the molecular dynamics simulations and permits the calculation of the wavenumber-dependent specific heat at constant pressure. The estimated wavenumber-dependent specific heats at constant volume and pressure, Cv(k and Cp(k, are shown to be in the long-wavelength limit in good agreement with the macroscopic experimental values of Cv and Cp for the studied thermodynamic points of supercritical Ar.

  5. Hydrodynamics of ultra-relativistic bubble walls

    Directory of Open Access Journals (Sweden)

    Leonardo Leitao

    2016-04-01

    Full Text Available In cosmological first-order phase transitions, gravitational waves are generated by the collisions of bubble walls and by the bulk motions caused in the fluid. A sizeable signal may result from fast-moving walls. In this work we study the hydrodynamics associated to the fastest propagation modes, namely, ultra-relativistic detonations and runaway solutions. We compute the energy injected by the phase transition into the fluid and the energy which accumulates in the bubble walls. We provide analytic approximations and fits as functions of the net force acting on the wall, which can be readily evaluated for specific models. We also study the back-reaction of hydrodynamics on the wall motion, and we discuss the extrapolation of the friction force away from the ultra-relativistic limit. We use these results to estimate the gravitational wave signal from detonations and runaway walls.

  6. Hydrodynamics of ultra-relativistic bubble walls

    Energy Technology Data Exchange (ETDEWEB)

    Leitao, Leonardo, E-mail: lleitao@mdp.edu.ar; Mégevand, Ariel, E-mail: megevand@mdp.edu.ar

    2016-04-15

    In cosmological first-order phase transitions, gravitational waves are generated by the collisions of bubble walls and by the bulk motions caused in the fluid. A sizeable signal may result from fast-moving walls. In this work we study the hydrodynamics associated to the fastest propagation modes, namely, ultra-relativistic detonations and runaway solutions. We compute the energy injected by the phase transition into the fluid and the energy which accumulates in the bubble walls. We provide analytic approximations and fits as functions of the net force acting on the wall, which can be readily evaluated for specific models. We also study the back-reaction of hydrodynamics on the wall motion, and we discuss the extrapolation of the friction force away from the ultra-relativistic limit. We use these results to estimate the gravitational wave signal from detonations and runaway walls.

  7. Hyperbolic metamaterial lens with hydrodynamic nonlocal response.

    Science.gov (United States)

    Yan, Wei; Mortensen, N Asger; Wubs, Martijn

    2013-06-17

    We investigate the effects of hydrodynamic nonlocal response in hyperbolic metamaterials (HMMs), focusing on the experimentally realizable parameter regime where unit cells are much smaller than an optical wavelength but much larger than the wavelengths of the longitudinal pressure waves of the free-electron plasma in the metal constituents. We derive the nonlocal corrections to the effective material parameters analytically, and illustrate the noticeable nonlocal effects on the dispersion curves numerically. As an application, we find that the focusing characteristics of a HMM lens in the local-response approximation and in the hydrodynamic Drude model can differ considerably. In particular, the optimal frequency for imaging in the nonlocal theory is blueshifted with respect to that in the local theory. Thus, to detect whether nonlocal response is at work in a hyperbolic metamaterial, we propose to measure the near-field distribution of a hyperbolic metamaterial lens.

  8. Smoothed Particle Hydrodynamics Coupled with Radiation Transfer

    Science.gov (United States)

    Susa, Hajime

    2006-04-01

    We have constructed a brand-new radiation hydrodynamics solver based upon Smoothed Particle Hydrodynamics, which works on a parallel computer system. The code is designed to investigate the formation and evolution of first-generation objects at z ≳ 10, where the radiative feedback from various sources plays important roles. The code can compute the fraction of chemical species e, H+, H, H-, H2, and H+2 by by fully implicit time integration. It also can deal with multiple sources of ionizing radiation, as well as radiation at Lyman-Werner band. We compare the results for a few test calculations with the results of one-dimensional simulations, in which we find good agreements with each other. We also evaluate the speedup by parallelization, which is found to be almost ideal, as long as the number of sources is comparable to the number of processors.

  9. Transversal expansion study in the Landau hydrodynamic

    International Nuclear Information System (INIS)

    Pottag, F.W.

    1984-01-01

    The system of equations in the frame of Landau's hydrodynamical model for multiparticle production at high energies is studied. Taking as a first approximation the one-dimensional exact due to Khalatnikov, and a special set of curvilinear coordinates, the radial part is separated from the longitudinal one in the equations of motion, and a system of partial differential equations (non-linear, hyperbolic) is obtained for the radial part. These equations are solved numerically by the method of caracteristics. The hydrodynamical variables are obtained over all the three-dimensional-flow region as well as its variation with the mass of the initially expanding system. Both, the transverse rapidity distribution of the fluid and the inclusive particle distribution at 90 0 in the center of mass system, are calculated. The last one is compared with recent experimental data. (author) [pt

  10. Numerical Hydrodynamics and Magnetohydrodynamics in General Relativity

    Directory of Open Access Journals (Sweden)

    Font José A.

    2008-09-01

    Full Text Available This article presents a comprehensive overview of numerical hydrodynamics and magnetohydrodynamics (MHD in general relativity. Some significant additions have been incorporated with respect to the previous two versions of this review (2000, 2003, most notably the coverage of general-relativistic MHD, a field in which remarkable activity and progress has occurred in the last few years. Correspondingly, the discussion of astrophysical simulations in general-relativistic hydrodynamics is enlarged to account for recent relevant advances, while those dealing with general-relativistic MHD are amply covered in this review for the first time. The basic outline of this article is nevertheless similar to its earlier versions, save for the addition of MHD-related issues throughout. Hence, different formulations of both the hydrodynamics and MHD equations are presented, with special mention of conservative and hyperbolic formulations well adapted to advanced numerical methods. A large sample of numerical approaches for solving such hyperbolic systems of equations is discussed, paying particular attention to solution procedures based on schemes exploiting the characteristic structure of the equations through linearized Riemann solvers. As previously stated, a comprehensive summary of astrophysical simulations in strong gravitational fields is also presented. These are detailed in three basic sections, namely gravitational collapse, black-hole accretion, and neutron-star evolutions; despite the boundaries, these sections may (and in fact do overlap throughout the discussion. The material contained in these sections highlights the numerical challenges of various representative simulations. It also follows, to some extent, the chronological development of the field, concerning advances in the formulation of the gravitational field, hydrodynamics and MHD equations and the numerical methodology designed to solve them. To keep the length of this article reasonable

  11. On an incompressible model in radiation hydrodynamics

    Czech Academy of Sciences Publication Activity Database

    Ducomet, B.; Nečasová, Šárka

    2015-01-01

    Roč. 38, č. 4 (2015), s. 765-774 ISSN 0170-4214 R&D Projects: GA ČR GA13-00522S Institutional support: RVO:67985840 Keywords : radiation hydrodynamics * incompressible Navier-Stokes-Fourier system * weak solution Subject RIV: BA - General Mathematics Impact factor: 1.002, year: 2015 http://onlinelibrary.wiley.com/doi/10.1002/mma.3107/abstract

  12. Degradation of chlorocarbons driven by hydrodynamic cavitation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Z.L.; Ondruschka, B.; Braeutigam, P. [Institut fuer Technische Chemie und Umweltchemie, Friedrich-Schiller-Universitaet Jena, Jena (Germany)

    2007-05-15

    To provide an efficient lab-scale device for the investigation of the degradation of organic pollutants driven by hydrodynamic cavitation, the degradation kinetics of chloroform and carbon tetrachloride and the increase of conductivity in aqueous solutions were measured. These are values which were not previously available. Under hydrodynamic cavitation conditions, the degradation kinetics for chlorocarbons was found to be pseudo first-order. Meanwhile, C-H and C-Cl bonds are broken, and Cl{sub 2}, Cl{sup .}, Cl{sup -} and other ions released can increase the conductivity and enhance the oxidation of KI in aqueous solutions. The upstream pressures of the orifice plate, the cavitation number, and the solution temperature have substantial effects on the degradation kinetics. A decreased cavitation number can result in more cavitation events and enhances the degradation of chlorocarbons and/or the oxidation of KI. A decrease in temperature is generally favorable to the cavitation chemistry. Organic products from the degradation of carbon tetrachloride and chloroform have demonstrated the formation and recombination of free radicals, e.g., CCl{sub 4}, C{sub 2}Cl{sub 4}, and C{sub 2}Cl{sub 6} are produced from the degradation of CHCl{sub 3}. CHCl{sub 3} and C{sub 2}Cl{sub 6} are produced from the degradation of CCl{sub 4}. Both the chemical mechanism and the reaction kinetics of the degradation of chlorocarbons induced by hydrodynamic cavitation are consistent with those obtained from the acoustic cavitation. Therefore, the technology of hydrodynamic cavitation should be a good candidate for the removal of organic pollutants from water. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  13. Relativistic charged fluids: hydrodynamic and kinetic approaches

    International Nuclear Information System (INIS)

    Debbasch, F.; Bonnaud, G.

    1991-10-01

    This report gives a rigorous and consistent hydrodynamic and kinetic description of a charged fluid and the basis equations, in a relativistic context. This study should lead to a reliable model, as much analytical as numerical, of relativistic plasmas which will appear in the interaction of a strong laser field with a plasma. For simplicity, we limited our study to a perfect fluid or, in other words, we disregarded the energy dissipation processes inside the fluid [fr

  14. Resolution of hydrodynamical equations for transverse expansions

    International Nuclear Information System (INIS)

    Hama, Y.; Pottag, F.W.

    1984-01-01

    The three-dimensional hydrodynamical expansion is treated with a method similar to that of Milekhin, but more explicit. Although in the final stage one have to appeal to numerical calculation, the partial differential equations governing the transverse expansions are treated without transforming them into ordinary equations with an introduction of averaged quantities. It is only concerned with the formalism and the numerical results will be given in the next paper. (Author) [pt

  15. Viscosity effect in Landau's hydrodynamical model

    International Nuclear Information System (INIS)

    Hoang, T.F.; Phua, K.K.; Nanyang Univ., Singapore

    1979-01-01

    The Bose-Einstein distribution is used to investigate Landau's hydrodynamical model with viscosity. In case the viscosity dependence on the temperature is T 3 , the correction to the multiplicity behaves like I/E and is found to be negligible for the pp data. A discussion is presented on a possibility of reconciling E 1 / 2 and logE dependence of the multiplicity law. (orig.)

  16. On the convexity of relativistic hydrodynamics

    International Nuclear Information System (INIS)

    Ibáñez, José M; Martí, José M; Cordero-Carrión, Isabel; Miralles, Juan A

    2013-01-01

    The relativistic hydrodynamic system of equations for a perfect fluid obeying a causal equation of state is hyperbolic (Anile 1989 Relativistic Fluids and Magneto-Fluids (Cambridge: Cambridge University Press)). In this report, we derive the conditions for this system to be convex in terms of the fundamental derivative of the equation of state (Menikoff and Plohr1989 Rev. Mod. Phys. 61 75). The classical limit is recovered. Communicated by L Rezzolla (note)

  17. Determining the hydrodynamic indices of contractions

    International Nuclear Information System (INIS)

    Blagov, Eh.E.

    2002-01-01

    The new dependences, making it possible only by measuring the flow rate and pressure drop on the contraction device (CD) with the known geometry, including the regulatory organ, in the non-crisis mode of the turbulent flow to calculate all the hydrodynamic indices of this device, including the pressure reduction in the jet contraction, are obtained. This simplifies and accelerates the CD hydraulic tests of all types. The new methodology for determining the cavitation factual start on the CD is proposed [ru

  18. Towards granular hydrodynamics in two dimensions

    International Nuclear Information System (INIS)

    Grossman, E.L.; Zhou, T.; Ben-Naim, E.; Ben-Naim, E.

    1997-01-01

    We study steady-state properties of inelastic gases in two dimensions in the presence of an energy source. We generalize previous hydrodynamic treatments to situations where high and low density regions coexist. The theoretical predictions compare well with numerical simulations in the nearly elastic limit. It is also seen that the system can achieve a nonequilibrium steady state with asymmetric velocity distributions, and we discuss the conditions under which such situations occur. copyright 1997 The American Physical Society

  19. Stochastic Hydrodynamic Synchronization in Rotating Energy Landscapes

    OpenAIRE

    Koumakis, N.; Di Leonardo, R.

    2013-01-01

    Hydrodynamic synchronization provides a general mechanism for the spontaneous emergence of coherent beating states in independently driven mesoscopic oscillators. A complete physical picture of those phenomena is of definite importance to the understanding of biological cooperative motions of cilia and flagella. Moreover, it can potentially suggest novel routes to exploit synchronization in technological applications of soft matter. We demonstrate that driving colloidal particles in rotating ...

  20. Hyperbolic metamaterial lens with hydrodynamic nonlocal response

    OpenAIRE

    Yan, Wei; Mortensen, N. Asger; Wubs, Martijn

    2013-01-01

    We investigate the effects of hydrodynamic nonlocal response in hyperbolic metamaterials (HMMs), focusing on the experimentally realizable parameter regime where unit cells are much smaller than an optical wavelength but much larger than the wavelengths of the longitudinal pressure waves of the free-electron plasma in the metal constituents. We derive the nonlocal corrections to the effective material parameters analytically, and illustrate the noticeable nonlocal effects on the dispersion cu...

  1. Hydrodynamic attraction of swimming microorganisms by surfaces

    OpenAIRE

    Berke, Allison P.; Turner, Linda; Berg, Howard C.; Lauga, Eric

    2008-01-01

    Cells swimming in confined environments are attracted by surfaces. We measure the steady-state distribution of smooth-swimming bacteria (Escherichia coli) between two glass plates. In agreement with earlier studies, we find a strong increase of the cell concentration at the boundaries. We demonstrate theoretically that hydrodynamic interactions of the swimming cells with solid surfaces lead to their re-orientation in the direction parallel to the surfaces, as well as their attraction by the c...

  2. Resolution of hydrodynamical equations for transverse expansions

    International Nuclear Information System (INIS)

    Hama, Y.; Pottag, F.W.

    1985-01-01

    The three-dimensional hydrodynamical expansion is treated with a method similar to that of Milekhin, but more explicit. Although in the final stage we have to appeal to numerical calculation, the partial differential equations governing the transverse expansions are treated without transforming them into ordinary equations with an introduction of averaged quantities. The present paper is concerned with the formalism and the numerical results will be reported in another paper. (Author) [pt

  3. A Platform for X-Ray Thomson Scattering Measurements of Radiation Hydrodynamics Experiments on the NIF

    Science.gov (United States)

    Lefevre, Heath; Ma, Kevin; Belancourt, Patrick; MacDonald, Michael; Doeppner, Tilo; Keiter, Paul; Kuranz, Carolyn

    2017-10-01

    A recent experiment on the National Ignition Facility (NIF) radiographed the evolution of the Rayleigh-Taylor (RT) instability under high and low drive cases. This experiment showed that under a high drive the growth rate of the RT instability is reduced relative to the low drive case. The high drive launches a radiative shock, increases the temperature of the post-shock region, and ablates the spikes, which reduces the RT growth rate. The plasma parameters must be measured to validate this claim. We present a target design for making X-Ray Thomson Scattering (XRTS) measurements on radiation hydrodynamics experiments on NIF to measure the electron temperature of the shocked region in the above cases. Specifically, we show that a previously fielded NIF radiation hydrodynamics platform can be modified to allow sufficient signal and temperature resolution for XRTS measurements. This work is funded by the NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas, Grant Number DE-NA0002956 and the National Science Foundation through the Basic Plasma Science and Engineering program.

  4. Hydrodynamic Modeling of Santa Marta's Big Marsh

    International Nuclear Information System (INIS)

    Saldarriaga, Juan

    1991-01-01

    The ecological degradation of Santa Marta's Big Marsh and their next areas it has motivated the realization of diagnosis studies and design by several state and private entities. One of the recommended efforts for international advisory it was to develop an ecological model that allowed the handling of the water body and the economic test of alternative of solution to those ecological problems. The first part of a model of this type is in turn a model that simulates the movement of the water inside the marsh, that is to say, a hydrodynamic model. The realization of this was taken charge to the civil engineering department, on the part of Colciencias. This article contains a general explanation of the hydrodynamic pattern that this being developed by a professors group. The ecological causes are described and antecedent, the parts that conform the complex of the Santa Marta big Marsh The marsh modeling is made and it is explained in qualitative form the model type Hydrodynamic used

  5. Hydrodynamic model research in Waseda group

    International Nuclear Information System (INIS)

    Muroya, Shin

    2010-01-01

    Constructing 'High Energy Material Science' had been proposed by Namiki as the guiding principle for the scientists of the high energy physics group lead by himself in Waseda University when the author started to study multiple particle production in 1980s toward the semi-phenomenological model for the quark gluon plasma (QGP). Their strategy was based on three stages to build an intermediate one between the fundamental theory of QCD and the phenomenological model. The quantum theoretical Langevin equation was taken up as the semi-phenomenological model at the intermediate stage and the Landau hydrodynamic model was chosen as the phenomenological model to focus on the 'phase transition' of QGP. A review is given here over the quantum theoretical Langevin equation formalism developed there and followed by the further progress with the 1+1 dimensional viscous fluid model as well as the hydrodynamic model with cylindrical symmetry. The developments of the baryon fluid model and Hanbury-Brown Twiss effect are also reviewed. After 1995 younger generation physicists came to the group to develop those models further. Activities by Hirano, Nonaka and Morita beyond the past generation's hydrodynamic model are picked up briefly. (S. Funahashi)

  6. Towards the concept of hydrodynamic cavitation control

    Science.gov (United States)

    Chatterjee, Dhiman; Arakeri, Vijay H.

    1997-02-01

    A careful study of the existing literature available in the field of cavitation reveals the potential of ultrasonics as a tool for controlling and, if possible, eliminating certain types of hydrodynamic cavitation through the manipulation of nuclei size present in a flow. A glass venturi is taken to be an ideal device to study the cavitation phenomenon at its throat and its potential control. A piezoelectric transducer, driven at the crystal resonant frequency, is used to generate an acoustic pressure field and is termed an ‘ultrasonic nuclei manipulator (UNM)’. Electrolysis bubbles serve as artificial nuclei to produce travelling bubble cavitation at the venturi throat in the absence of a UNM but this cavitation is completely eliminated when a UNM is operative. This is made possible because the nuclei, which pass through the acoustic field first, cavitate, collapse violently and perhaps fragment and go into dissolution before reaching the venturi throat. Thus, the potential nuclei for travelling bubble cavitation at the venturi throat seem to be systematically destroyed through acoustic cavitation near the UNM. From the solution to the bubble dynamics equation, it has been shown that the potential energy of a bubble at its maximum radius due to an acoustic field is negligible compared to that for the hydrodynamic field. Hence, even though the control of hydrodynamic macro cavitation achieved in this way is at the expense of acoustic micro cavitation, it can still be considered to be a significant gain. These are some of the first results in this direction.

  7. The hydrodynamic size of polymer stabilized nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Krueger, Karl M; Al-Somali, Ali M; Mejia, Michelle; Colvin, Vicki L [Department of Chemistry, Rice University, MS-60 6100 Main Street, Houston, TX 77005 (United States)

    2007-11-28

    For many emerging applications, nanocrystals are surface functionalized with polymers to control self-assembly, prevent aggregation, and promote incorporation into polymer matrices and biological systems. The hydrodynamic diameter of these nanoparticle-polymer complexes is a critical factor for many applications, and predicting this size is complicated by the fact that the structure of the grafted polymer at a nanocrystalline interface is not generally established. In this work we evaluate using size-exclusion chromatography the overall hydrodynamic diameter of nanocrystals (Au, CdSe, d<5 nm) surface coated with polystyrene of varying molecular weight. The polymer is tethered to the nanoparticles via a terminal thiol to provide strong attachment. Our data show that at full coverage the polymer assumes a brush conformation and is 44% longer than the unbound polymer in solution. The brush conformation is confirmed by comparison with models used to describe polymer brushes at flat interfaces. From this work, we suggest an empirical formula which predicts the hydrodynamic diameter of polymer coated nanoparticles based on the size of the nanoparticle core and the size of the randomly coiled unbound polymer in solution.

  8. Hydrodynamic slip length as a surface property

    Science.gov (United States)

    Ramos-Alvarado, Bladimir; Kumar, Satish; Peterson, G. P.

    2016-02-01

    Equilibrium and nonequilibrium molecular dynamics simulations were conducted in order to evaluate the hypothesis that the hydrodynamic slip length is a surface property. The system under investigation was water confined between two graphite layers to form nanochannels of different sizes (3-8 nm). The water-carbon interaction potential was calibrated by matching wettability experiments of graphitic-carbon surfaces free of airborne hydrocarbon contamination. Three equilibrium theories were used to calculate the hydrodynamic slip length. It was found that one of the recently reported equilibrium theories for the calculation of the slip length featured confinement effects, while the others resulted in calculations significantly hindered by the large margin of error observed between independent simulations. The hydrodynamic slip length was found to be channel-size independent using equilibrium calculations, i.e., suggesting a consistency with the definition of a surface property, for 5-nm channels and larger. The analysis of the individual trajectories of liquid particles revealed that the reason for observing confinement effects in 3-nm nanochannels is the high mobility of the bulk particles. Nonequilibrium calculations were not consistently affected by size but by noisiness in the smallest systems.

  9. Hydrodynamic instabilities in astrophysics and ICF

    International Nuclear Information System (INIS)

    Paul Drake, R.

    2005-01-01

    Inertial fusion systems and astrophysical systems both involve hydrodynamic effects, including sources of pressure, shock waves, rarefactions, and plasma flows. In the evolution of such systems, hydrodynamic instabilities naturally evolve. As a result, a fundamental understanding of hydrodynamic instabilities is necessary to understand their behavior. In addition, high-energy-density facilities designed for ICF purposes can be used to provide and experimental basis for understanding astrophysical processes. In this talk. I will discuss the instabilities that appear in astrophysics and ICF from the common perspective of the basic mechanisms at work. Examples will be taken from experiments aimed at ICF, from astrophysical systems, and from experiments using ICF systems to address issues in astrophysics. The high-energy-density research facilities of today can accelerate small but macroscopic amounts of material to velocities above 100 km/s, can heat such material to temperature above 100 eV, can produce pressures far above a million atmospheres (10''12 dybes/cm''2 or 0.1 TPascal), and can do experiments under these conditions that address basic physics issues. This enables on to devise experiments aimed directly at important process such as the Rayleigh Taylor instability at an ablating surface or at an embedded interface that is accelerating, the Richtmeyer Meshkov evolution of shocked interfaces, and the Kelvin-Helmholtz instability of shear flows. The talk will include examples of such phenomena from the laboratory and from astrophysics, and will discuss experiments to study them. (Author)

  10. On being dyslexic: Student radiographers' perspectives

    International Nuclear Information System (INIS)

    Murphy, Fred

    2011-01-01

    The purpose of this paper was to provide an insight into life as a dyslexic student radiographer, identify barriers and risks in clinical training, and develop recommendations for the support of students with dyslexia. The paucity of research into dyslexia within the radiography profession is worrying, with attention focused only on the support provided by Higher Education Institutions (HEI) or inferences drawn from the experiences of other healthcare students. The impact and significance of dyslexia for student radiographers in clinical practice has never been investigated. Results: On a self-reporting scale of clinical tasks there was little or no difference between dyslexic students and non-dyslexics. Some minor traits commonly associated with dyslexics were also reported by students with no learning disabilities and an inclusion support plan for all students was advocated. In-depth interviews of 10 student radiographers revealed six distinct themes of visualising the disability, self-protection, strengths and talents, time, the badge of disability and adjustments and support. Like other healthcare students, some radiography students reported significant difficulties and prejudices and very little structured support in the clinical environment. Despite the Special Educational Needs and Disability Act being in place for several years, the support in clinical departments fell significantly short of that provided in the universities. The dyslexic students took extra responsibility for their own learning and some had developed complex coping strategies to overcome any difficulties. Conclusion: Several inclusive recommendations were developed as a result of this study that could be used to support all students on clinical placement.

  11. Retention of anatomy knowledge by student radiographers

    International Nuclear Information System (INIS)

    Hall, A. Susanne; Durward, Brian R.

    2009-01-01

    Introduction: Anatomy has long been regarded as an integral part of the core curriculum. However, anecdotal evidence suggests that long-term retention of anatomy knowledge may be deficient. This study aims to evidence whether student radiographers demonstrate the same level of knowledge of anatomy after a period of time has elapsed and to correlate to approaches to learning and studying. Methodology: A repeated measures design was utilised to measure retention of anatomy knowledge for both MCQs and short-response answers to a Practical Radiographic Anatomy Examination; alpha value p < 0.05. Fifty-one students from levels 2 and 3 were retested after a time lapse of 10 and 22 months respectively. The students were not aware that their knowledge was being retested. Approaches to learning and studying were measured using the ASSIST inventory. Results: Statistical analysis found no difference in performance on MCQ assessment, in either the combined sample or levels 2 and 3 separately, from baseline to retention occasions; average retention rate being 99%. However, a statistical difference in performance on PRAE assessment was found, with level 2 experiencing a larger reduction in scores; retention rate of 67% compared to level 3 at 77%. The students perceived themselves to be principally strategic in their approach to learning and studying but no strong relationships were found when correlated to test scores. Conclusion: The student radiographers in this study demonstrated varied anatomy retention rates dependent on assessment method employed and time interval that had elapsed. It is recommended that diverse teaching and assessment strategies are adopted to encourage a deeper approach to learning and studying.

  12. Segmentation of ribs in digital chest radiographs

    Science.gov (United States)

    Cong, Lin; Guo, Wei; Li, Qiang

    2016-03-01

    Ribs and clavicles in posterior-anterior (PA) digital chest radiographs often overlap with lung abnormalities such as nodules, and cause missing of these abnormalities, it is therefore necessary to remove or reduce the ribs in chest radiographs. The purpose of this study was to develop a fully automated algorithm to segment ribs within lung area in digital radiography (DR) for removal of the ribs. The rib segmentation algorithm consists of three steps. Firstly, a radiograph was pre-processed for contrast adjustment and noise removal; second, generalized Hough transform was employed to localize the lower boundary of the ribs. In the third step, a novel bilateral dynamic programming algorithm was used to accurately segment the upper and lower boundaries of ribs simultaneously. The width of the ribs and the smoothness of the rib boundaries were incorporated in the cost function of the bilateral dynamic programming for obtaining consistent results for the upper and lower boundaries. Our database consisted of 93 DR images, including, respectively, 23 and 70 images acquired with a DR system from Shanghai United-Imaging Healthcare Co. and from GE Healthcare Co. The rib localization algorithm achieved a sensitivity of 98.2% with 0.1 false positives per image. The accuracy of the detected ribs was further evaluated subjectively in 3 levels: "1", good; "2", acceptable; "3", poor. The percentages of good, acceptable, and poor segmentation results were 91.1%, 7.2%, and 1.7%, respectively. Our algorithm can obtain good segmentation results for ribs in chest radiography and would be useful for rib reduction in our future study.

  13. Chest radiographic manifestations of scrub typhus

    Directory of Open Access Journals (Sweden)

    KPP Abhilash

    2016-01-01

    Full Text Available Background and Rationale: Respiratory system involvement in scrub typhus is seen in 20–72% of patients. In endemic areas, good understanding and familiarity with the various radiologic findings of scrub typhus are essential in identifying pulmonary complications. Materials and Methods: Patients admitted to a tertiary care center with scrub typhus between October 2012 and September 2013 and had a chest X ray done were included in the analysis. Details and radiographic findings were noted and factors associated with abnormal X-rays were analyzed. Results: The study cohort contained 398 patients. Common presenting complaints included fever (100%, generalized myalgia (83%, headache (65%, dyspnea (54%, cough (24.3%, and altered sensorium (14%. Almost half of the patients (49.4% had normal chest radiographs. Common radiological pulmonary abnormalities included pleural effusion (14.6%, acute respiratory distress syndrome (14%, airspace opacity (10.5%, reticulonodular opacities (10.3%, peribronchial thickening (5.8%, and pulmonary edema (2%. Cardiomegaly was noted in 3.5% of patients. Breathlessness, presence of an eschar, platelet counts of 2 mg/dL had the highest odds of having an abnormal chest radiograph. Patients with an abnormal chest X-ray had a higher requirement of noninvasive ventilation (odds ratio [OR]: 13.98; 95% confidence interval CI: 5.89–33.16, invasive ventilation (OR: 18.07; 95% CI: 6.42–50.88, inotropes (OR: 8.76; 95% CI: 4.35–17.62, higher involvement of other organ systems, longer duration of hospital stay (3.18 ± 3 vs. 7.27 ± 5.58 days; P< 0.001, and higher mortality (OR: 4.63; 95% CI: 1.54–13.85. Conclusion: Almost half of the patients with scrub typhus have abnormal chest radiographs. Chest radiography should be included as part of basic evaluation at presentation in patients with scrub typhus, especially in those with breathlessness, eschar, jaundice, and severe thrombocytopenia.

  14. Automatic segmentation of vertebrae from radiographs

    DEFF Research Database (Denmark)

    Mysling, Peter; Petersen, Peter Kersten; Nielsen, Mads

    2011-01-01

    Segmentation of vertebral contours is an essential task in the design of automatic tools for vertebral fracture assessment. In this paper, we propose a novel segmentation technique which does not require operator interaction. The proposed technique solves the segmentation problem in a hierarchical...... is constrained by a conditional shape model, based on the variability of the coarse spine location estimates. The technique is evaluated on a data set of manually annotated lumbar radiographs. The results compare favorably to the previous work in automatic vertebra segmentation, in terms of both segmentation...

  15. Radiographic imaging system for high energy radiation

    International Nuclear Information System (INIS)

    1975-01-01

    A radiographic imaging system for high energy radiation is described utilizing a detector of such radiation and a mask having regions relatively transparent to such radiation and interspersed among regions relatively opaque to such radiation. A relative motion is imparted between the mask and the detector, the detector providing a time varying signal in response to the incident radiation and in response to the relative motion. The time varying signal provides, with the aid of a decoder, an image of a source of such radiation

  16. Improvements in or relating to radiographic apparatus

    International Nuclear Information System (INIS)

    Hounsfield, G.N.

    1978-01-01

    Radiographic apparatus is described for examining part of the interior of a body by means of penetrating radiation including a packing member comprising a bag containing particulate or viscous material, having an absorption to the radiation similar to that of human tissue, the member as a whole being flexible and being adapted to be placed in contact with the body in the vicinity of the part to be examined. Locating means, arranged to maintain the member in place, and means for disposing the locating means in a predetermined position with respect to the source of the radiation are provided. (author)

  17. Radiographic imaging system for high energy radiation

    International Nuclear Information System (INIS)

    Barrett, H.H.

    1976-01-01

    A radiographic imaging system for high energy radiation utilizing a detector of such radiation and a mask having regions relatively transparent to such radiation interspersed among regions relatively opaque to such radiation is described. A relative motion is imparted between the mask and the detector, the detector providing a time varying signal in response to the incident radiation and in response to the relative motion. The time varying signal provides, with the aid of a decoder, an image of a source of such radiation

  18. Radiographic investigations during medico-legal autopsies

    International Nuclear Information System (INIS)

    Bratzke, H.; Schneider, V.; Dietz, W.

    1982-01-01

    During the last 13 years (1968-1980), 427 radiographic examinations were carried out during the course of medico-legal autopsies at the Institute of Forensic Medicine at the Free University of Berlin. Important problems were the demonstration of retained foreign bodies resulting from shooting, stabbing or blunt trauma, bone injuries, identification, and the question of life in neonates. An historical survey is given and 12 cases with special forensic problems are illustrated and discussed, and further means of investigations are described. (orig.) [de

  19. Radiographic analysis of temporomandibular joint arthrosis

    Energy Technology Data Exchange (ETDEWEB)

    You, Dong Soo [Department of Oral Radiology, College of Dentistry, Seoul National University, Seoul (Korea, Republic of)

    1984-11-15

    The author analysed the bone changes, the positional relationships between condylar head and articular fossa, and the interrelationship between the bone changes and the abnormal position of condylar head, from 1,036 radiographs of 259 patients with temporomandibular joint arthrosis, which were obtained by the oblique-lateral transcranial projection and orthopantomograms. The results were as follows: 1. Among the radiographic bone changes of the temporomandibular joint arthrosis, deformity was 36..90% (217 cases), sclerosis 34.18% (201 cases), erosive change 25.58% (152 cases) and marginal proliferation 3.06% (18 cases) respectively. 2. In the positional changes between condylar head and articular fossa, the downward positioning of condylar head in centric occlusion was most frequent (36.90%), of which frequency was significantly higher than forward positioning (11.22%) and backward positioning (4.76%) in same condition. Also, radiographs showed that the enlargement of articular space showed higher frequency than its narrowing. In the opening position of mouth, the restrict ed movement of condylar head within articular fossa was most frequent (35.03%). The forward positioning and the downward positioning was 15.65% and 9.52% respectively. Also, radiographs revealed that the incomplete movement or no positional change of condylar head was most frequent. 3. In the interrelationship between bone changes and abnormal position of condylar head, deformity was 42.79% in the cases of downward positioning of condylar head in centric occlusion and 37.50% in those of normal positioning of condylar head in same condition. This revealed that deformity was most frequent bone change in above condylar positionings. However, erosive change was 34.62% in the cases of downward positioning of condylar head in centric occlusion and 33 .33% in those of forward positioning. In opening position of condylar head, and deformity in the cases of norma l positioning, forward positioning and

  20. Radiographic film orientation in radiotherapy dosimetry

    International Nuclear Information System (INIS)

    Suchowerska, N.; Davison, A.; Drew, J.; Metcalfe, P.

    1996-01-01

    Since the discovery of x-rays, film has been used as a detection medium for radiation. More recently radiographic film has become established as a practical tool for the measurement of dose distribution in radiotherapy. The accuracy and reproducibility of film dosimetry depends on photon energy, processing conditions and film plane orientation. The relationship between photon energy, processing conditions and film dosimetry accuracy has been studied. The role of film plane orientation is still controversial. The current work aims to clarify the effects film plane orientation has on film dosimetry. Poster 205. (author)

  1. General-purpose radiographic and fluoroscopic table

    International Nuclear Information System (INIS)

    Ishizaki, Noritaka

    1982-01-01

    A new series of diagnostic tables, Model DT-KEL, was developed for general-purpose radiographic and fluoroscopic systems. Through several investigations, the table was so constructed that the basic techniques be general radiography and GI examination, and other techniques be optionally added. The diagnostic tables involve the full series of the type for various purposes and are systematized with the surrounding equipment. A retractable mechanism of grids was adopted first for general use. The fine grids with a density of 57 lines per cm, which was adopted in KEL-2, reduced the X-ray doses by 16 percent. (author)

  2. Revolutionizing radiographic diagnostic accuracy in periodontics

    Directory of Open Access Journals (Sweden)

    Brijesh Sharma

    2016-01-01

    Full Text Available Effective diagnostic accuracy has in some way been the missing link between periodontal diagnosis and treatment. Most of the clinicians rely on the conventional two-dimensional (2D radiographs. But being a 2D image, it has its own limitations. 2D images at times can give an incomplete picture about the severity or type of disease and can further affect the treatment plan. Cone beam computed tomography (CBCT has a better potential for detecting periodontal bone defects with accuracy. The purpose here is to describe how CBCT imaging is beneficial in accurate diagnosis and will lead to a precise treatment plan.

  3. Normal radiographic findings. 4. act. ed.

    International Nuclear Information System (INIS)

    Moeller, T.B.

    2003-01-01

    This book can serve the reader in three ways: First, it presents normal findings for all radiographic techniques including KM. Important data which are criteria of normal findings are indicated directly in the pictures and are also explained in full text and in summary form. Secondly, it teaches the systematics of interpreting a picture - how to look at it, what structures to regard in what order, and for what to look in particular. Checklists are presented in each case. Thirdly, findings are formulated in accordance with the image analysis procedure. All criteria of normal findings are defined in these formulations, which make them an important didactic element. (orig.)

  4. Radiographic analysis of temporomandibular joint arthrosis

    International Nuclear Information System (INIS)

    You, Dong Soo

    1984-01-01

    The author analysed the bone changes, the positional relationships between condylar head and articular fossa, and the interrelationship between the bone changes and the abnormal position of condylar head, from 1,036 radiographs of 259 patients with temporomandibular joint arthrosis, which were obtained by the oblique-lateral transcranial projection and orthopantomograms. The results were as follows: 1. Among the radiographic bone changes of the temporomandibular joint arthrosis, deformity was 36..90% (217 cases), sclerosis 34.18% (201 cases), erosive change 25.58% (152 cases) and marginal proliferation 3.06% (18 cases) respectively. 2. In the positional changes between condylar head and articular fossa, the downward positioning of condylar head in centric occlusion was most frequent (36.90%), of which frequency was significantly higher than forward positioning (11.22%) and backward positioning (4.76%) in same condition. Also, radiographs showed that the enlargement of articular space showed higher frequency than its narrowing. In the opening position of mouth, the restrict ed movement of condylar head within articular fossa was most frequent (35.03%). The forward positioning and the downward positioning was 15.65% and 9.52% respectively. Also, radiographs revealed that the incomplete movement or no positional change of condylar head was most frequent. 3. In the interrelationship between bone changes and abnormal position of condylar head, deformity was 42.79% in the cases of downward positioning of condylar head in centric occlusion and 37.50% in those of normal positioning of condylar head in same condition. This revealed that deformity was most frequent bone change in above condylar positionings. However, erosive change was 34.62% in the cases of downward positioning of condylar head in centric occlusion and 33 .33% in those of forward positioning. In opening position of condylar head, and deformity in the cases of norma l positioning, forward positioning and

  5. Normal radiographic findings. 4. act. ed.; Roentgennormalbefunde

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, T.B. [Gemeinschaftspraxis fuer Radiologie und Nuklearmedizin, Dillingen (Germany)

    2003-07-01

    This book can serve the reader in three ways: First, it presents normal findings for all radiographic techniques including KM. Important data which are criteria of normal findings are indicated directly in the pictures and are also explained in full text and in summary form. Secondly, it teaches the systematics of interpreting a picture - how to look at it, what structures to regard in what order, and for what to look in particular. Checklists are presented in each case. Thirdly, findings are formulated in accordance with the image analysis procedure. All criteria of normal findings are defined in these formulations, which make them an important didactic element. (orig.)

  6. Contribution to identification of factors causing radiographic image unsharpness

    International Nuclear Information System (INIS)

    Branzan, C.; Popescu, A.; Radu, R.

    1995-01-01

    Radiographic image quality is crucial for the ability of the radiographic method to give us a maximum information about the macroscopic structure of materials and pieces, investigated by penetrating radiation. Radiographic image quality depends on several factors. A high quality image is able to show small and typical defects. One of the most important factor affecting radiographic image is unsharpness. The total effective unsharpness of the film must be some function of several factors and their contribution is taken into account by summing up different kinds of unsharpness: geometric unsharpness, internal unsharpness, screen unsharpness, and accidental unsharpness. This work analyses the weight of the radiographic image unsharpness and the possibilities for determining its influence on the quality of the radiographic image. (author)

  7. Commitment of the radiographer - does it matter to the patient?

    International Nuclear Information System (INIS)

    Blagoeva, D.; Shuleva, L.; Goudeva, V.; Stoinova, V.

    2015-01-01

    Full text: Radiographers are responsible for providing safe and accurate imaging examinations in a wide range of clinical environments, using a variety of imaging modalities and techniques so that appropriate management and treatment of patients and clients can proceed. The purpose of this presentation is to discuss: the responsibilities of radiographer in the clinical radiology department; their professional judgment to decide how to achieve a diagnostic outcome; the relationship patient/radiographer; the impact of the radiographer on patient care. Patient care and advocacy has always been an integral part of the radiography profession. The radiographer should respect the patient at all the times, be genuine in nature and empathies with the patient‘s condition. Good listening and observational skills are also very important components. The radiographers are personally accountable for their work and professional conduct

  8. Radiographic evaluation of coxofemoral joint laxity in dogs part I: New stress-radiographic positioning techniques

    International Nuclear Information System (INIS)

    Phiwipha Kamonrat; Duangdaun Kaenkangploo

    2002-01-01

    Two new stress-radiographic positioning techniques, namely 60 deg and 90 deg stress techniques, were introduced for quantifying hip joint laxity in dogs. The comparative characteristics and efficiency of these new techniques with angled hindlimbs were evaluated relative to the standard hip-extended radiographic technique. Forty, healthy, mongrel dogs with normal hip joint conformation were anesthetized and placed in dorsal recumbency before 3 radiograhps of the standard, 60 deg , and 90 deg stress techniques were taken. For the 60 deg stress technique, hindlimbs were extended in parallel to each other at 60 deg angled to the table top and stifles were slightly rotated inward, femoral heads were manually pushed in a craniodorsal direction during exposure. For the 90 deg stress technique, femurs were positioned perpendicular to the table top, stifles were 90 deg flexed and adducted and femoral heads were manually pushed in a craniodorsal direction during exposure. The subluxation index (SI) and dorsolateral subluxation score (DLS score) were calculated from 3 radiographic views for both hip joints to quantitate the relative degree of joint laxity. Results of the study indicated that the 60 deg (SI = 0.20+-0.045, DLS score = 62.5+-7.96 percent) and 90 deg (SI = 0.23+-0.044, DLS score = 61.2+-9.47 percent) stress-radiographs yielded significantly (p0.001) higher degree of hip joint laxity than the standard technique (SI)

  9. Radiographic analysis of partial or total vertebral body resection

    International Nuclear Information System (INIS)

    Whitten, C.G.; Hammer, G.H.; El-Khoury, G.Y.; Hugus, J.; Weinstein, J.N.

    1991-01-01

    Partial and total vertebrectomies are used in the treatment of primary and metastatic neoplasms of the spine. Serial radiographic studies are crucial in the follow-up of patients with vertebrectomies. This paper presents 33 cases and illustrates radiographic examples of both successful and complicated vertebrectomies, including radiographic signs of local tumor recurrence, loosening, migration or fracture of the hardware or methylmethacrylate, bone graft failure, and progressive spinal instability

  10. Xeroradiographic and radiographic anatomy of the channel catfish, Ictalurus punctatus

    International Nuclear Information System (INIS)

    Smith, S.A.; Smith, B.J.

    1994-01-01

    The purpose of this study was to provide an anatomic reference for the channel catfish (Ictalurus punctatus) using xeroradiography† and conventional radiography. The entire body of three adult fish was radiographed using standard xeroradiographic and conventional radiographic techniques. Two xeroradiographs and their corresponding conventional radiographs were selected, and the xeroradiographs labeled to illustrate the normal skeletal and soft-tissue anatomy of the channel catfish

  11. Occupational stress and its predictors in radiographers

    Energy Technology Data Exchange (ETDEWEB)

    Rutter, D.R. [Centre for Research in Health Behaviour, Department of Psychology, University of Kent, Keynes College, Canterbury CT2 7NP (United Kingdom)], E-mail: d.r.rutter@kent.ac.uk; Lovegrove, M.J. [Department of Allied Health Professions, London South Bank University, London SE1 0AA (United Kingdom)

    2008-05-15

    Purpose: The purpose of this study was to establish the level of occupational stress in UK NHS radiographers, and to examine its causes. A total of more than 1600 radiographers sampled nationally completed a postal questionnaire. Four groups were represented - mammography, diagnostics, radiotherapy, and ultrasound - and both junior staff and superintendents were examined. Method: The questionnaire measured role ambiguity, role conflict, work problems, social support from colleagues, and perceived stress. Results: Levels of perceived stress were high in all four groups. The mean was significantly lower in the mammography group than the others, however, and junior staff reported lower levels than superintendents. Role ambiguity, role conflict and work problems all contributed significantly to stress, but the effects were sometimes buffered by social support from colleagues. Conclusion: The implications of the findings are discussed for theory and for policy and practice: occupational stress was predicted by intrinsic features of the job; the levels were similar to those reported by other NHS professionals; and the pattern of findings suggests possible ways to intervene to reduce it.

  12. Radiographic film: surface dose extrapolation techniques

    International Nuclear Information System (INIS)

    Cheung, T.; Yu, P.K.N.; Butson, M.J.; Cancer Services, Wollongong, NSW; Currie, M.

    2004-01-01

    Full text: Assessment of surface dose delivered from radiotherapy x-ray beams for optimal results should be performed both inside and outside the prescribed treatment fields An extrapolation technique can be used with radiographic film to perform surface dose assessment for open field high energy x-ray beams. This can produce an accurate 2 dimensional map of surface dose if required. Results have shown that surface % dose can be estimated within ±3% of parallel plate ionisation chamber results with radiographic film using a series of film layers to produce an extrapolated result. Extrapolated percentage dose assessment for 10cm, 20cmand 30cm square fields was estimated to be 15% ± 2%, 29% ± 3% and 38% ± 3% at the central axis and relatively uniform across the treatment field. Corresponding parallel plate ionisation chamber measurement are 16%, 27% and 37% respectively. Surface doses are also measured outside the treatment field which are mainly due to scattered electron contamination. To achieve this result, film calibration curves must be irradiated to similar x-ray field sizes as the experimental film to minimize quantitative variations in film optical density caused by varying x-ray spectrum with field size. Copyright (2004) Australasian College of Physical Scientists and Engineers in Medicine

  13. Radiographic Control of 137-Cs Brachytherapy Sources

    International Nuclear Information System (INIS)

    Bistrovic, M.; Viculin, T.; Jurkovic, S.

    2003-01-01

    1 37C s brachytherapy sources are practical for the intracavitary application due to their relatively long lifetime (T 1/2 = 30 y). On the other hand, due to the relatively low energy (0.66 MeV) of the emitted photons, they are suitable for an efficient radiation protection. The dose distribution around the sources is usually calculated by a specific program. However this program requires the knowledge of the position of sources within the applicator as well as the distribution of activity along them. The only way to learn these data is to make an X-ray picture of applicators and sources superimposed to the autoradiography of every source. It is difficult to achieve satisfactory radiographs with high dose rate sources with standard X-ray film material because autoradiography covers the structure of the radiographic shadow. The problem can be overcome either by applying a high intensity X-ray or gamma beam (originating from a radiotherapeutic machine), or by using photographic material of very low sensitivity, for example photographic paper. Combining both possibilities one can obtain satisfactory images. (author)

  14. Lead arthropathy: radiographic, CT and MRI findings

    International Nuclear Information System (INIS)

    Fernandes, Joao Luiz; Lopes Rocha, Arthemizio Antonio; Veloso Ayrimoraes Soares, Mayra; Lopes Viana, Sergio

    2007-01-01

    Lead arthropathy is a well-known complication of gunshot injuries with retained intra-articular bullets. Although several previous reports have discussed the radiological findings of this entity, computed tomography (CT) and magnetic resonance imaging (MRI) findings have never been described before in this setting. In this paper the authors review the imaging findings of 11 patients with lead arthropathy (1 of whom had clinical signs of lead poisoning as well), all of them studied by means of radiographs. In addition, non-enhanced CT scans were obtained in 3 patients and gadolinium-enhanced MRI in 1. Classic findings of intra-articular speckled lead deposits (occasionally with a ''lead arthrogram'' appearance), joint space narrowing and preserved bone density were found at radiographs in the great majority of cases. Furthermore, extension of intra-articular lead to adjacent tendon sheaths was observed in almost half of the patients, an observation rarely reported in the literature. CT scans and MRI, in their turn, were superior with regard to soft tissue abnormalities, accurately depicting joint effusion and the thickened synovium with lead particles embedded in it. Post-gadolinium MRI had the advantage of showing the enhancement pattern of the inflamed synovium and associated bone marrow edema pattern. Although it is not possible to establish the role of axial imaging in lead arthropathy from the small number of cases studied, this initial experience shows that both methods hold promise in this setting and may be useful, at least in selected cases. (orig.)

  15. Occupational stress and its predictors in radiographers

    International Nuclear Information System (INIS)

    Rutter, D.R.; Lovegrove, M.J.

    2008-01-01

    Purpose: The purpose of this study was to establish the level of occupational stress in UK NHS radiographers, and to examine its causes. A total of more than 1600 radiographers sampled nationally completed a postal questionnaire. Four groups were represented - mammography, diagnostics, radiotherapy, and ultrasound - and both junior staff and superintendents were examined. Method: The questionnaire measured role ambiguity, role conflict, work problems, social support from colleagues, and perceived stress. Results: Levels of perceived stress were high in all four groups. The mean was significantly lower in the mammography group than the others, however, and junior staff reported lower levels than superintendents. Role ambiguity, role conflict and work problems all contributed significantly to stress, but the effects were sometimes buffered by social support from colleagues. Conclusion: The implications of the findings are discussed for theory and for policy and practice: occupational stress was predicted by intrinsic features of the job; the levels were similar to those reported by other NHS professionals; and the pattern of findings suggests possible ways to intervene to reduce it

  16. Image quality in digital radiographic systems

    Directory of Open Access Journals (Sweden)

    Almeida Solange Maria de

    2003-01-01

    Full Text Available The aim of the present study was to evaluate the image quality of four direct digital radiographic systems. Radiographs were made of the maxillary central incisor and mandibular left molar regions of a dry skull, and an aluminum step-wedge. The X-ray generator operated at 10 mA, 60 and 70 kVp, and images were acquired with 3, 5, 8, 12, 24 and 48 exposure pulses. Six well-trained observers classified the images by means of scores from 1 to 3. Collected data were submitted to nonparametric statistical analysis using Fisher's exact test. Statistical analysis showed significant differences (p<0.01 in image quality with the four systems. Based on the results, it was possible to conclude that: 1 all of the digital systems presented good performance in producing acceptable images for diagnosis, if the exposures of the step-wedge and the maxillary central incisor region were made at 5 pulses, as well as at 8 pulses for the mandibular left molar region, selecting 60 or 70kVp; 2 higher percentages of acceptable images were obtained with the administration of lower radiation doses in CCD-sensors (charge-coupled device; 3 the Storage Phosphor systems produced acceptable images at a large range of exposure settings, that included low, intermediate and high radiation doses.

  17. Necrotizing fasciitis : plain radiographic and CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chang Dae; Park, Jeong Hee; Jeon, Hae Jeong; Lim, Jong Nam; Heo, Tae Haeng; Park, Dong Rib [Konkuk Univ. College of Medicine, Seoul (Korea, Republic of)

    1996-11-01

    To evaluate the plain radiographic and CT findings of the necrotizing fasciitis. We retrospectively reviewed the radiologic findings of 4 cases with necrotizing fasciitis. Three cases were proven pathologically. We evaluated pattern and extent of the gas shadows in plain films. CT findings were analysed, with emphasis on : (a) gas pattern, (b) extent, (c) location and involved site, (d) associated focal abscess, and (e) swelling of the adjacent muscles. On plain radiographs, four cases showed streaky or mottled gas densities in the pelvis, three cases in the perineum, one case in the abdomen, and two cases in the thigh. On CT images, gas pattern was mottled and streaky appearance with swelling of the adjacent muscles. Gas shadows located in the extraperitoneal space in four cases, fascial layer in four cases, and subcutaneous layer in four cases. There were gas shadows in pelvic wall, perineum, abdominal wall, buttock, thigh, and scrotum. Focal low density lesion suggestive of focal abscess was not visualized. Plain radiography is useful for early diagnosis of the necrotizing fasciitis and CT is very useful for detection of precise location and extent of the disease. CT is also useful for differentiation of necrotizing fasciitis from focal abscess and cellulitis.

  18. MRI and radiographic findings in Currarino's triad

    International Nuclear Information System (INIS)

    Pfluger, T.; Czekalla, R.; Koletzko, S.; Muensterer, O.; Willemsen, U.F.; Hahn, K.

    1996-01-01

    Currarino's triad is a rare complex of a congential sacral bony abnormality, anorectal malformation and a presacral mass. Intractable constipation since birth is the leading symptom of this triad, which follows an autosomal dominant mode of heredity. We report conventional radiographic and MR findings in one family consisting of a mother and her two daughters. In all three cases, radiography revealed an abnormality of the os sacrum, the so-called scimitar sacrum. MR examination, undertaken next in our institution, was applied with T1-, T2- and proton density weighted sequences in all three orientations before and after i.v. application of gadolinium diethylene-triamine-pentaacetic acid (Gd-DTPA). In two patients we were able to diagnose the complete form of the triad and in one patient an incomplete form. In any case of a radiographically diagnosed scimitar sacrum in combination with constipation. Currarino's triad should be considered. MRI, as the method of choice, should be the next step to detect a presacral mass and any anomalies of the spinal canal. The importance of early recognition lies in the high morbidity and mortality rates resulting from this disorder. (orig.)

  19. Monte Carlo simulation for radiographic applications

    International Nuclear Information System (INIS)

    Tillack, G.R.; Bellon, C.

    2003-01-01

    Standard radiography simulators are based on the attenuation law complemented by built-up-factors (BUF) to describe the interaction of radiation with material. The assumption of BUF implies that scattered radiation reduces only the contrast in radiographic images. This simplification holds for a wide range of applications like weld inspection as known from practical experience. But only a detailed description of the different underlying interaction mechanisms is capable to explain effects like mottling or others that every radiographer has experienced in practice. The application of Monte Carlo models is capable to handle primary and secondary interaction mechanisms contributing to the image formation process like photon interactions (absorption, incoherent and coherent scattering including electron-binding effects, pair production) and electron interactions (electron tracing including X-Ray fluorescence and Bremsstrahlung production). It opens up possibilities like the separation of influencing factors and the understanding of the functioning of intensifying screen used in film radiography. The paper discusses the opportunities in applying the Monte Carlo method to investigate special features in radiography in terms of selected examples. (orig.) [de

  20. Surface dose extrapolation measurements with radiographic film

    International Nuclear Information System (INIS)

    Butson, Martin J; Cheung Tsang; Yu, Peter K N; Currie, Michael

    2004-01-01

    Assessment of surface dose delivered from radiotherapy x-ray beams for optimal results should be performed both inside and outside the prescribed treatment fields. An extrapolation technique can be used with radiographic film to perform surface dose assessment for open field high energy x-ray beams. This can produce an accurate two-dimensional map of surface dose if required. Results have shown that the surface percentage dose can be estimated within ±3% of parallel plate ionization chamber results with radiographic film using a series of film layers to produce an extrapolated result. Extrapolated percentage dose assessment for 10 cm, 20 cm and 30 cm square fields was estimated to be 15% ± 2%, 29% ± 3% and 38% ± 3% at the central axis and relatively uniform across the treatment field. The corresponding parallel plate ionization chamber measurements are 16%, 27% and 37%, respectively. Surface doses are also measured outside the treatment field which are mainly due to scattered electron contamination. To achieve this result, film calibration curves must be irradiated to similar x-ray field sizes as the experimental film to minimize quantitative variations in film optical density caused by varying x-ray spectrum with field size. (note)

  1. Reflections on the role of consultant radiographers in the UK: What is a consultant radiographer?

    International Nuclear Information System (INIS)

    Booth, L.; Henwood, S.; Miller, P.

    2016-01-01

    Context: This paper is the second paper from a two year in depth case study, exploring the role of consultant radiographers in the UK. Methods: A longitudinal case study approach was used to determine the role of consultant radiographers. Interviews were used to explore experiences of being a consultant, which were analysed using thematic analysis. Eight consultant radiographers participated (Note, two of the consultants withdrew after the first interview due to workload). Therefore two consultants were interviewed only once. The remaining six consultants were interviewed twice over a 12 month period. Findings: The data presented in this paper explores the nature of the role, differences between roles, the four domains of practice, and how the role fits into local organisational structures. The study shows wide variation in the types of roles undertaken, reflecting that the creation of these roles were in response to local clinical need and often related to an individual practitioner's skills. The broad scope of the role was shown across all the consultants, with evidence of roles developing into new areas of service delivery. Conclusions: The paper offers insight into the role(s) of consultant radiographers in the UK. The range and scope of their practice is extensive, with much variation. It is evident that the clinical aspect of the role dominates, with research being the least supported domain of practice. There remains a lack of clarity around the role, with concerns about remuneration and other limitations that may restrict the role developing further. - Highlights: • This paper shows the variation in roles between consultant radiographers. • The commonality with medical roles is highlighted. • Problem solving is identified as a core skill in consultant radiography. • Consultants offered evidence of the roles developing service provision. • While all four domains of practice are covered, research is the least well supported.

  2. Common pitfalls in radiographic interpretation of the Thorax

    International Nuclear Information System (INIS)

    Godshalk, C.P.

    1994-01-01

    Errors in radiographic interpretation of the thorax are common. Many mistakes result from interpreting normal anatomic variants as abnormalstructures, such as misdiagnosing dorsal and rightward deviation of the cranial thoracic trachea on lateral radiographs of normal dogs. Some of the more common errors specifically relate to misinterpretation of radiographs made on obese patients. The age of the patient also plays a role in misdiagnosis. Aging cats seem to have a horizontally positioned heart on lateral radiographs, and older dogs, primarily collies,often have pulmonary osteomas that are misdiagnosed as metastatic neoplastic disease or healed pulmonary fungal infections

  3. Radiographic and tomographic study of the elbow joint in dogs

    International Nuclear Information System (INIS)

    Sendyk-Grunkraut, Alessandra; Martin, Claudia M.; Souza, Alexandre N.A.; Patricio, Geni Cristina F.; Lorigados, Carla A.B.; Matera, Julia M.; Fonseca-Pinto, Ana C.B.C.

    2017-01-01

    Elbow dysplasia disease includes an united anconeal process, fragmented medial coronoid process, osteochondrosis of humeral trochlea, articular incongruity and degenerative joint disease. The aim of this study was to present detailed morphologic and morphometric aspects of the elbow joint in dog in clinical and correlate with radiographic and tomographic (CT) exam. Inter-observer variation for articular incongruity measurements by CT, comparative analysis in the radiographic exam, angle in ulnar notch and its comparative analysis between radiographic and tomographic agreement examination in 44 elbow of dogs with different ages were evaluated. The statistics analyses included the kappa coefficient and interclass correlation and Fischer's test and McNemar's test. It was evidenced that individual performance of each radiographic incidence had poor agreement with the tomographic exam, suggesting that the accomplishment of more than two radiograph views are needed. There was no agreement between the three evaluators in the ulnar notch angle at radiographic and tomographic exams. However, there was good/moderate agreement for articular incongruity measurement in the sagittal plane between evaluators. It was possible to conclude that none of the five radiographic incidences was better than the others for radiographic analysis because each incidence had a better identification of a particular elbow compartment; measurements at the tomographic exam to evaluate radioulnar incongruity had no reproductiveness in the frontal plane, but in sagittal plan had a good/moderate agreement between observers and the angle in ulnar notch presented no repeatability at radiographic exam and no reproductiveness at tomographic exam. (author)

  4. Radiographic evaluation of dentigerous cyst with cone beam CT

    International Nuclear Information System (INIS)

    Park, Yong Chan; Lee, Wan; Lee, Byung Do

    2010-01-01

    The purpose of this study was to accurately analyze the radiographic characteristics of dentigerous cyst (DC) with multiplanar images of cone beam computed tomography (CBCT). Thirty eight radiographically and histopathologically proven cases of DCs were analyzed with panoramic radiograph and CBCT, retrospectively. The radiographic CT pattern, symmetry of radiolucency around the unerupted tooth crown, ratio of long length to short length, degree of cortical bone alternation, effects on adjacent tooth, and cyst size were analyzed. Relative frequencies of these radiographic features were evaluated. In order to compare the CBCT features of DC with those of odontogenic keratocyst (OKC), 9 cases of OKCs were analyzed with the same method radiographically. DCs consisted of thirty unilocular cases (79.0%), seven lobulated cases (18.4%) and one multilocular case (2.6%). Eight were asymmetric (21.0%) and thirty were symmetric (79.0%). Maxillary DC showed rounder shape than mandibular DC (L/S ratio; maxilla 1.32, mandible 1.67). Alternations of lingual cortical bone (14 cases, 48.2%) were more frequent than those of buccal side (7 cases, 24.1%). CBCT images of DC showed definite root resorption and bucco-lingual tooth displacement. These findings were hardly observed on panoramic radiographs of DCs. Comparison of CBCT features of DC with those of OKC showed several different features. CBCT images of DC showed various characteristic radiographic features. Therefore, CBCT can be helpful for the diagnosis of DC radiographically.

  5. Radiographic evaluation of dentigerous cyst with cone beam CT

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yong Chan; Lee, Wan; Lee, Byung Do [School of Dentisity, Wonkwang University, Iksan (Korea, Republic of)

    2010-09-15

    The purpose of this study was to accurately analyze the radiographic characteristics of dentigerous cyst (DC) with multiplanar images of cone beam computed tomography (CBCT). Thirty eight radiographically and histopathologically proven cases of DCs were analyzed with panoramic radiograph and CBCT, retrospectively. The radiographic CT pattern, symmetry of radiolucency around the unerupted tooth crown, ratio of long length to short length, degree of cortical bone alternation, effects on adjacent tooth, and cyst size were analyzed. Relative frequencies of these radiographic features were evaluated. In order to compare the CBCT features of DC with those of odontogenic keratocyst (OKC), 9 cases of OKCs were analyzed with the same method radiographically. DCs consisted of thirty unilocular cases (79.0%), seven lobulated cases (18.4%) and one multilocular case (2.6%). Eight were asymmetric (21.0%) and thirty were symmetric (79.0%). Maxillary DC showed rounder shape than mandibular DC (L/S ratio; maxilla 1.32, mandible 1.67). Alternations of lingual cortical bone (14 cases, 48.2%) were more frequent than those of buccal side (7 cases, 24.1%). CBCT images of DC showed definite root resorption and bucco-lingual tooth displacement. These findings were hardly observed on panoramic radiographs of DCs. Comparison of CBCT features of DC with those of OKC showed several different features. CBCT images of DC showed various characteristic radiographic features. Therefore, CBCT can be helpful for the diagnosis of DC radiographically.

  6. Radiographic aspects of Pneumocystis carinii pneumonia in the miniature dachshund

    International Nuclear Information System (INIS)

    Kirberger, R.M.; Lobetti, R.G.

    1998-01-01

    The thoracic radiographic changes of Pneumocystis carinii in 7 miniature Dachshunds were reviewed, The dogs were 7-12 months old and presented with polypnea, exercise intolerance and clinical signs suggestive of immune-incompetence. P. carinii pneumonia was diagnosed in all the dogs using transtracheal aspirate cytology and confirmed at postmortemin 3 dogs that died. Radiographically, diffuse pulmonary changes we represent and varied from a mild interstitial and bronchial pattern to an alveolar pattern. Radiographic evidence of cor pulmonale was present in 1 dog. The most severe radiographic changes were seen in 2 of the dogs that died

  7. Radiographic anatomy of the medial coronoid process of dogs

    International Nuclear Information System (INIS)

    Miyabayashi, T.; Takiguchi, M.; Schrader, S.C.; Biller, D.S.

    1995-01-01

    Mediolateral, flexed mediolateral, mediocaudal-laterocranial 15 degrees oblique (extended and supinated mediolateral), and craniolateral-caudomedial 20 degrees to 30 degrees oblique radiographs of 16 elbow-joint specimens were produced to study the radiographic anatomy of the medial coronoid process. On the mediolateral view, the cranial point of the coronoid process was at the level of the distal one-third of the radial epiphysis. Degree of superimposition of the proximal radius and ulna determined how the medial coronoid process was projected on the radiographs. Mediocaudal-laterocranial oblique radiographs best showed the cranial outline of the medial coronoid process with moderate superimposition of the proximal radius and ulna

  8. Radiographic caries diagnosis and restorative treatment decision making

    International Nuclear Information System (INIS)

    Mileman, P.A.

    1985-01-01

    This thesis is concerned with a single diagnostic technique: the bitewing radiograph, and the way it is used by dentists to decide on patient treatment need for interproximal caries. The variation in caries diagnosis and treatment decisions using bitewing radiographs is described and the radiographic criteria of choice for minimizing over and undertreatment according to a norm are investigated. Three possible diagnostic strategies in interproximal caries diagnosis using a decision analysis approach are described and evaluated, and the effect of the reported diagnostic behaviour and knowledge of practicing Dutch dentists in their use of bitewing radiographs for the diagnosis and treatment of interproximal caries is described and analyzed. (Auth.)

  9. Assessment for hydrodynamic masses of HANARO flow tubes

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Jeong Soo; Cho, Yeong Garp; Kim, Doo Kie; Woo, Jong Sug; Park, Jin Ho

    2000-06-01

    The effect of hydrodynamic masses is investigated in dynamic characteristics and seismic response analyses of the submerged HANARO hexagonal flow tubes. Consistent hydrodynamic masses of the surrounding water are evaluated by the prepared program using the finite element method, in which arbitrary cross-sections of submerged structures and boundary conditions of the surrounding fluid can be considered. Also lumped hydrodynamic masses are calculated using simple formula applied to hexagonal flow tubes in the infinite fluid. Modal analyses and seismic response spectrum analyses were performed using hydrodynamic masses obtained by the finite element method and the simple formula. The results of modal analysis were verified by comparing the results measured from modal tests. And the displacement results of the seismic response spectrum analysis were assessed by comparing the consistent and the lumped hydrodynamic masses obtained by various methods. Finally practical criteria based on parametric studies are proposed as the lumped hydrodynamic masses for HANARO flow tubes.

  10. Assessment for hydrodynamic masses of HANARO flow tubes

    International Nuclear Information System (INIS)

    Ryu, Jeong Soo; Cho, Yeong Garp; Kim, Doo Kie; Woo, Jong Sug; Park, Jin Ho

    2000-06-01

    The effect of hydrodynamic masses is investigated in dynamic characteristics and seismic response analyses of the submerged HANARO hexagonal flow tubes. Consistent hydrodynamic masses of the surrounding water are evaluated by the prepared program using the finite element method, in which arbitrary cross-sections of submerged structures and boundary conditions of the surrounding fluid can be considered. Also lumped hydrodynamic masses are calculated using simple formula applied to hexagonal flow tubes in the infinite fluid. Modal analyses and seismic response spectrum analyses were performed using hydrodynamic masses obtained by the finite element method and the simple formula. The results of modal analysis were verified by comparing the results measured from modal tests. And the displacement results of the seismic response spectrum analysis were assessed by comparing the consistent and the lumped hydrodynamic masses obtained by various methods. Finally practical criteria based on parametric studies are proposed as the lumped hydrodynamic masses for HANARO flow tubes

  11. Simulated radiographic bone and joint modeling from 3D ankle MRI: feasibility and comparison with radiographs and 2D MRI

    Energy Technology Data Exchange (ETDEWEB)

    Nordeck, Shaun M. [University of Texas Southwestern Medical College, Dallas, TX (United States); University of Texas Southwestern Medical Center, Musculoskeletal Radiology, Dallas, TX (United States); Koerper, Conrad E.; Adler, Aaron [University of Texas Southwestern Medical College, Dallas, TX (United States); Malhotra, Vidur; Xi, Yin [University of Texas Southwestern Medical Center, Musculoskeletal Radiology, Dallas, TX (United States); Liu, George T. [University of Texas Southwestern Medical Center, Orthopaedic Surgery, Dallas, TX (United States); Chhabra, Avneesh [University of Texas Southwestern Medical Center, Musculoskeletal Radiology, Dallas, TX (United States); University of Texas Southwestern Medical Center, Orthopaedic Surgery, Dallas, TX (United States)

    2017-05-15

    The purpose of this work is to simulate radiographs from isotropic 3D MRI data, compare relationship of angle and joint space measurements on simulated radiographs with corresponding 2D MRIs and real radiographs (XR), and compare measurement times among the three modalities. Twenty-four consecutive ankles were included, eight males and 16 females, with a mean age of 46 years. Segmented joint models simulating radiographs were created from 3D MRI data sets. Three readers independently performed blinded angle and joint space measurements on the models, corresponding 2D MRIs, and XRs at two time points. Linear mixed models and the intraclass correlation coefficient (ICC) was ascertained, with p values less than 0.05 considered significant. Simulated radiograph models were successfully created in all cases. Good agreement (ICC > 0.65) was noted among all readers across all modalities and among most measurements. Absolute measurement values differed between modalities. Measurement time was significantly greater (p < 0.05) on 2D versus simulated radiographs for most measurements and on XR versus simulated radiographs (p < 0.05) for nearly half the measurements. Simulated radiographs can be successfully generated from 3D MRI data; however, measurements differ. Good inter-reader and moderate-to-good intra-reader reliability was observed and measurements obtained on simulated radiograph models took significantly less time compared to measurements with 2D and generally less time than XR. (orig.)

  12. An overview of hydrodynamic studies of mineralization

    Directory of Open Access Journals (Sweden)

    Guoxiang Chi

    2011-07-01

    Full Text Available Fluid flow is an integral part of hydrothermal mineralization, and its analysis and characterization constitute an important part of a mineralization model. The hydrodynamic study of mineralization deals with analyzing the driving forces, fluid pressure regimes, fluid flow rate and direction, and their relationships with localization of mineralization. This paper reviews the principles and methods of hydrodynamic studies of mineralization, and discusses their significance and limitations for ore deposit studies and mineral exploration. The driving forces of fluid flow may be related to fluid overpressure, topographic relief, tectonic deformation, and fluid density change due to heating or salinity variation, depending on specific geologic environments and mineralization processes. The study methods may be classified into three types, megascopic (field observations, microscopic analyses, and numerical modeling. Megascopic features indicative of significantly overpressured (especially lithostatic or supralithostatic fluid systems include horizontal veins, sand injection dikes, and hydraulic breccias. Microscopic studies, especially microthermometry of fluid inclusions and combined stress analysis and microthermometry of fluid inclusion planes (FIPs can provide important information about fluid temperature, pressure, and fluid-structural relationships, thus constraining fluid flow models. Numerical modeling can be carried out to solve partial differential equations governing fluid flow, heat transfer, rock deformation and chemical reactions, in order to simulate the distribution of fluid pressure, temperature, fluid flow rate and direction, and mineral precipitation or dissolution in 2D or 3D space and through time. The results of hydrodynamic studies of mineralization can enhance our understanding of the formation processes of hydrothermal deposits, and can be used directly or indirectly in mineral exploration.

  13. Hydrodynamic evolution of neutron star merger remnants

    Science.gov (United States)

    Liu, Men-Quan; Zhang, Jie

    2017-11-01

    Based on the special relativistic hydrodynamic equations and updated cooling function, we investigate the long-term evolution of neutron stars merger (NSM) remnants by a one-dimensional hydrodynamic code. Three NSM models from one soft equation of state, SFHo, and two stiff equations of state, DD2 and TM1, are used to compare their influences on the hydrodynamic evolution of remnants. We present the luminosity, mass and radius of remnants, as well as the velocity, temperature and density of shocks. For a typical interstellar medium (ISM) density with solar metallicity, we find that the NSM remnant from the SFHo model makes much more changes to ISM in terms of velocity, density and temperature distributions, compared with the case of DD2 and TM1 models. The maximal luminosity of the NSM remnant from the SFHo model is 3.4 × 1038 erg s-1, which is several times larger than that from DD2 and TM1 models. The NSM remnant from the SFHo model can maintain high luminosity (>1038 erg s-1) for 2.29 × 104 yr. Furthermore, the density and temperature of remnants at the maximal luminosity are not sensitive to the power of the original remnant. For the ISM with the solar metallicity and nH = 1 cm- 3, the density of the first shock ∼10-23 g cm-3 and the temperature ∼3 × 105 K in the maximal luminosity phase; The temperature of the first shock decreases and there is a thin 'dense' shell with density ∼10-21 g cm-3 after the maximal luminosity. These characteristics may be helpful for future observations of NSM remnants.

  14. Computer simulation of the fire-tube boiler hydrodynamics

    Directory of Open Access Journals (Sweden)

    Khaustov Sergei A.

    2015-01-01

    Full Text Available Finite element method was used for simulating the hydrodynamics of fire-tube boiler with the ANSYS Fluent 12.1.4 engineering simulation software. Hydrodynamic structure and volumetric temperature distribution were calculated. The results are presented in graphical form. Complete geometric model of the fire-tube boiler based on boiler drawings was considered. Obtained results are suitable for qualitative analysis of hydrodynamics and singularities identification in fire-tube boiler water shell.

  15. Measurement of beam driven hydrodynamic turbulence

    International Nuclear Information System (INIS)

    Norem, J.; Black, E.; Bandura, L.; Errede, D.; Cummings, M. A. C.

    2003-01-01

    Cooling intense muon beams in liquid hydrogen absorbers introduces kW of heating to the cold fluid, which will drive turbulent flow. The amount of turbulence may be sufficient to help cool the liquid, but calculations are difficult. We have used a 20 MeV electron beam in a water tank to look at the scale of the beam driven convection and turbulence. The density and flow measurements are made with schlieren and Ronchi systems. We describe the optical systems and the turbulence measured. These data are being used to calibrate hydrodynamic calculations of convection driven and forced flow cooling in muon cooling absorbers

  16. The frontal method in hydrodynamics simulations

    Science.gov (United States)

    Walters, R.A.

    1980-01-01

    The frontal solution method has proven to be an effective means of solving the matrix equations resulting from the application of the finite element method to a variety of problems. In this study, several versions of the frontal method were compared in efficiency for several hydrodynamics problems. Three basic modifications were shown to be of value: 1. Elimination of equations with boundary conditions beforehand, 2. Modification of the pivoting procedures to allow dynamic management of the equation size, and 3. Storage of the eliminated equations in a vector. These modifications are sufficiently general to be applied to other classes of problems. ?? 1980.

  17. Hydrodynamic instabilities in inertial confinement fusion

    International Nuclear Information System (INIS)

    Hoffman, N.M.

    1995-01-01

    The focus of these (two) lectures is on buoyancy-driven instabilities of the Rayleigh-Taylor type, which are commonly regarded as the most important kind of hydrodynamic instability in inertial-confinement-fusion implosions. The paper is intended to be pedagogical rather than research-oriented, and so is by no means a comprehensive review of work in this field. Rather, it is hoped that the student will find here a foundation on which to build an understanding of current research, and the experienced researcher will find a compilation of useful results. (author)

  18. Hydrodynamic Study Of Column Bioleaching Processes

    Directory of Open Access Journals (Sweden)

    Sadowski Zygmunt

    2015-06-01

    Full Text Available The modelling of flow leaching solution through the porous media has been considered. The heap bioleaching process can be tested using the column experimental equipment. This equipment was employed to the hydrodynamic studies of copper ore bioleaching. The copper ore (black shale ore with the support, inertial materials (glass small balls and polyethylene beads was used to the bioleaching tests. The packed beds were various composition, the ore/support ratio was changed. The correlation between the bed porosity and bioleaching kinetics, and copper recovery was investigated.

  19. Hydrodynamic instabilities in an ablation front

    International Nuclear Information System (INIS)

    Piriz, A R; Portugues, R F

    2004-01-01

    The hydrodynamic stability of an ablation front is studied for situations in which the wavelength of the perturbations is larger than the distance to the critical surface where the driving radiation is absorbed. An analytical model is presented, and it shows that under conditions in which the thermal flux is limited within the supercritical region of the ablative corona, the front may behave like a flame or like an ablation front, depending on the perturbation wavelength. For relatively long wavelengths the critical and ablation surfaces practically lump together into a unique surface and the front behaves like a flame, whereas for the shortest wavelengths the ablation front substructure is resolved

  20. Hydrodynamic instabilities in an ablation front

    Energy Technology Data Exchange (ETDEWEB)

    Piriz, A R; Portugues, R F [E.T.S.I. Industriales, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain)

    2004-06-01

    The hydrodynamic stability of an ablation front is studied for situations in which the wavelength of the perturbations is larger than the distance to the critical surface where the driving radiation is absorbed. An analytical model is presented, and it shows that under conditions in which the thermal flux is limited within the supercritical region of the ablative corona, the front may behave like a flame or like an ablation front, depending on the perturbation wavelength. For relatively long wavelengths the critical and ablation surfaces practically lump together into a unique surface and the front behaves like a flame, whereas for the shortest wavelengths the ablation front substructure is resolved.