WorldWideScience

Sample records for tube transmission source

  1. Production and guide tube transmission of very cold neutrons from pulsed cold source

    International Nuclear Information System (INIS)

    Utsuro, Masahiko; Okumura, Kiyoshi

    1982-01-01

    The intensity and the energy spectra of Very Cold Neutrons (VCN) transmitted through a curved guide tube were measured by using the time-of-flight method of VCN. In the measurements, the curved guide tube having a characteristic neutron velocity of about 70 m/s is combined to a pulsed cold source of an electron linac in an internal target geometry. A space dependence of the VCN spectra was observed on the radial positions of a detector at the guide tube exit. A simple theoretical analysis on the transmission of VCN in the curved guide tube is also presented with taking into consideration about the effects of a finite size and a finite distance of the VCN-emitting source, and simple analytical formulas for the exit spectra of the guide tube are given. Comparisons between the experimental results and the theoretical calculations show good agreements, and the satisfactory performance of the present VCN guide tube assembly was ascertained. These results present also instructive features for understanding the structures and the space dependence of the exit spectra of a neutron guide tube. The VCN spectra at the guide tube exit can be divided into a few energy regions according to the transmission processes of VCN. Thus, the present study provides useful informations for the preparations of a VCN source with a curved guide tube. (author)

  2. Method and system for a gas tube switch-based voltage source high voltage direct current transmission system

    Science.gov (United States)

    She, Xu; Chokhawala, Rahul Shantilal; Zhou, Rui; Zhang, Di; Sommerer, Timothy John; Bray, James William

    2016-12-13

    A voltage source converter based high-voltage direct-current (HVDC) transmission system includes a voltage source converter (VSC)-based power converter channel. The VSC-based power converter channel includes an AC-DC converter and a DC-AC inverter electrically coupled to the AC-DC converter. The AC-DC converter and a DC-AC inverter include at least one gas tube switching device coupled in electrical anti-parallel with a respective gas tube diode. The VSC-based power converter channel includes a commutating circuit communicatively coupled to one or more of the at least one gas tube switching devices. The commutating circuit is configured to "switch on" a respective one of the one or more gas tube switching devices during a first portion of an operational cycle and "switch off" the respective one of the one or more gas tube switching devices during a second portion of the operational cycle.

  3. Method and system for a gas tube-based current source high voltage direct current transmission system

    Science.gov (United States)

    She, Xu; Chokhawala, Rahul Shantilal; Bray, James William; Sommerer, Timothy John; Zhou, Rui; Zhang, Di

    2017-08-29

    A high-voltage direct-current (HVDC) transmission system includes an alternating current (AC) electrical source and a power converter channel that includes an AC-DC converter electrically coupled to the electrical source and a DC-AC inverter electrically coupled to the AC-DC converter. The AC-DC converter and the DC-AC inverter each include a plurality of legs that includes at least one switching device. The power converter channel further includes a commutating circuit communicatively coupled to one or more switching devices. The commutating circuit is configured to "switch on" one of the switching devices during a first portion of a cycle of the H-bridge switching circuits and "switch off" the switching device during a second portion of the cycle of the first and second H-bridge switching circuits.

  4. Coaxial tube array space transmission line characterization

    International Nuclear Information System (INIS)

    Switzer, C.A.; Bents, D.J.

    1987-01-01

    The coaxial tube array tether/transmission line used to connect an SP-100 nuclear power system to the space station was characterized over the range of reactor-to-platform separation distances of 1 to 10 km. Characterization was done with respect to array performance, physical dimensions and masses. Using a fixed design procedure, a family of designs was generated for the same power level (300 kWe), power loss (1.5 percent), and meteoroid survival probability (99.5 percent over 10 yr). To differentiate between vacuum insulated and gas insulated lines, two different maximum values of the E field were considered: 20 kV/cm (appropriate to vacuum insulation) and 50 kV/cm (compressed SF6). Core conductor, tube, bumper, standoff, spacer and bumper support dimensions, and masses were also calculated. The results of the characterization show mainly how transmission line size and mass scale with reactor-to-platform separation distance

  5. Transmission imaging with a coded source

    International Nuclear Information System (INIS)

    Stoner, W.W.; Sage, J.P.; Braun, M.; Wilson, D.T.; Barrett, H.H.

    1976-01-01

    The conventional approach to transmission imaging is to use a rotating anode x-ray tube, which provides the small, brilliant x-ray source needed to cast sharp images of acceptable intensity. Stationary anode sources, although inherently less brilliant, are more compatible with the use of large area anodes, and so they can be made more powerful than rotating anode sources. Spatial modulation of the source distribution provides a way to introduce detailed structure in the transmission images cast by large area sources, and this permits the recovery of high resolution images, in spite of the source diameter. The spatial modulation is deliberately chosen to optimize recovery of image structure; the modulation pattern is therefore called a ''code.'' A variety of codes may be used; the essential mathematical property is that the code possess a sharply peaked autocorrelation function, because this property permits the decoding of the raw image cast by th coded source. Random point arrays, non-redundant point arrays, and the Fresnel zone pattern are examples of suitable codes. This paper is restricted to the case of the Fresnel zone pattern code, which has the unique additional property of generating raw images analogous to Fresnel holograms. Because the spatial frequency of these raw images are extremely coarse compared with actual holograms, a photoreduction step onto a holographic plate is necessary before the decoded image may be displayed with the aid of coherent illumination

  6. Neutron generator tube ion source control

    International Nuclear Information System (INIS)

    Bridges, J.R.

    1982-01-01

    A system is claimed for controlling the output of a neutron generator tube of the deuterium-tritium accelerator type and having an ion source to produce sharply defined pulses of neutrons for well logging use. It comprises: means for inputting a relatively low voltage input control pulse having a leading edge and a trailing edge; means, responsive to the input control pulse, for producing a relatively high voltage ion source voltage pulse after receipt of the input pulse; and means, responsive to the input control pulse, for quenching, after receipt of the input pulse, the ion source control pulse, thereby providing a sharply time defined neutron output from the generator tube

  7. Transmission efficiency of neutron guide tube with alignment errors

    International Nuclear Information System (INIS)

    Kawabata, Yuji; Suzuki, Masatoshi; Sakamoto, Masanobu; Harami, Taikan; Takahashi, Hidetake; Onishi, Nobuaki

    1990-01-01

    The experimental studies on the neutron transmission efficiencies of neutron guide tubes were carried out by using thermal neutrons from the JAERI electron linac. The neutron guide tube facility on a large scale have been planned on the reconstructed JRR-3 in JAERI. The neutron efficiencies of the 1/10 scale neutron guide tube, which is 2 mm width and 1.8 m length, with and without appreciable alignment errors were studied to evaluate the efficiencies of the planned ones. Calculated results by the Neutron Guide Tube Analysis Code 'NEUGT' were also assessed by these neutron experiments. The experimental results agree well with the calculated results by 'NEUGT' even with alignment errors. From this experimental study, the efficiency of the planned neutron guide tubes is estimated to be good enough for the neutron beam experiments. (author)

  8. Orbiting transmission source for positron tomography

    International Nuclear Information System (INIS)

    Huesman, R.H.; Derenzo, S.E.; Cahoon, J.L.; Geyer, A.B.; Moses, W.W.; Uber, D.C.; Vuletich, T.; Budinger, T.F.

    1988-01-01

    Accidental suppression and effective data rates have been measured for the orbiting transmission source as implemented in the Donner 600-Crystal Positron Tomograph. A mechanical description of the orbiting source and a description of the electronics used to discard scattered and accidental events is included. Since accidental coincidences were the rate-limiting factor in transmission data acquisition, the new method allows us to acquire sufficient transmission data in a shorter time with a more active transmission source

  9. Neutron generator tube ion source control apparatus

    International Nuclear Information System (INIS)

    Bridges, J.R.

    1982-01-01

    A pulsed neutron well logging system includes a neutron generator tube of the deuterium-tritium accelerator type and an ion source control apparatus providing extremely sharply time-defined neutron pulses. A low voltage control pulse supplied to an input by timing circuits turns a power FET on via a buffer-driver whereby a 2000 volt pulse is produced in the secondary of a pulse transformer and applied to the ion source of the tube. A rapid fall in this ion source control pulse is ensured by a quenching circuit wherein a one-shot responds to the falling edge of the control pulse and produces a 3 microsecond delay to compensate for the propagation delay. A second one-shot is triggered by the falling edge of the output of the first one-shot and gives an 8 microsecond pulse to turn on the power FET which, via an isolation transformer turns on a series-connected transistor to ground the secondary of the pulse transformer and the ion source. (author)

  10. Investigation of hydraulic transmission noise sources

    Science.gov (United States)

    Klop, Richard J.

    Advanced hydrostatic transmissions and hydraulic hybrids show potential in new market segments such as commercial vehicles and passenger cars. Such new applications regard low noise generation as a high priority, thus, demanding new quiet hydrostatic transmission designs. In this thesis, the aim is to investigate noise sources of hydrostatic transmissions to discover strategies for designing compact and quiet solutions. A model has been developed to capture the interaction of a pump and motor working in a hydrostatic transmission and to predict overall noise sources. This model allows a designer to compare noise sources for various configurations and to design compact and inherently quiet solutions. The model describes dynamics of the system by coupling lumped parameter pump and motor models with a one-dimensional unsteady compressible transmission line model. The model has been verified with dynamic pressure measurements in the line over a wide operating range for several system structures. Simulation studies were performed illustrating sensitivities of several design variables and the potential of the model to design transmissions with minimal noise sources. A semi-anechoic chamber has been designed and constructed suitable for sound intensity measurements that can be used to derive sound power. Measurements proved the potential to reduce audible noise by predicting and reducing both noise sources. Sound power measurements were conducted on a series hybrid transmission test bench to validate the model and compare predicted noise sources with sound power.

  11. Source Terms for HFIR Beam Tube Shielding Analyses, and a Complete Shielding Analysis of the HB-3 Tube

    International Nuclear Information System (INIS)

    Bucholz, J.A.

    2000-01-01

    The High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory is in the midst of a massive upgrade program to enhance experimental facilities. The reactor presently has four horizontal experimental beam tubes, all of which will be replaced or redesigned. The HB-2 beam tube will be enlarged to support more guide tubes, while the HB-4 beam tube will soon include a cold neutron source

  12. Source Terms for HFIR Beam Tube Shielding Analyses, and a Complete Shielding Analysis of the HB-3 Tube

    Energy Technology Data Exchange (ETDEWEB)

    Bucholz, J.A.

    2000-07-01

    The High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory is in the midst of a massive upgrade program to enhance experimental facilities. The reactor presently has four horizontal experimental beam tubes, all of which will be replaced or redesigned. The HB-2 beam tube will be enlarged to support more guide tubes, while the HB-4 beam tube will soon include a cold neutron source.

  13. Characteristics of Transmission-type Microfocus X-ray Tube based-on Carbon Nanotube Field Emitter

    International Nuclear Information System (INIS)

    Heo, Sung Hwan; Ihsan, Aamir; Cho, Sung Oh

    2007-01-01

    A high resolution microfocus x-ray source is widely applied to noninvasive detection for industrial demands, material science and engineering, and to diagnostic study of microbiology and micro-tomography. Carbon nanotube (CNT) is regarded as an excellent electron emitter, which outperforms conventional electron sources in point of brightness. It has been suggested that CNT is used as an electron source of a high resolution x-ray tube according to their low threshold field with atomically sharp geometry, chemically robust structure, and electric conductivity. Several researchers have reported miniaturized x-ray tube based on diode structure and micro x-ray radiography and computed tomography systems using triode types with precise emission control and electrostatic focusing. Especially, a microfocus x-ray source of 30 μm resolution has been demonstrated recently using an elliptical CNT cathode and asymmetrical Eingel lens. However, to increase the spatial resolution of x-ray source, a smaller CNT emitter is desired. Electron focusing optics must be corrected to reduce aberrations. A thin wire tip end can provide a micro-area of CNT substrate, and a magnetic lens and transmission x-ray target are proper to reduce the lens aberration and a focal length. Until now, CNT based microfocus x-ray source with less than 10 um resolution has not been shown. Here we report a microfocus x-ray source with 4.7 μm x-ray focal spot consisted of a conical CNT tip, a single solenoid lens, and a transmission type x-ray target. A magnified x-ray image larger than 230 times was resolved with advantage of microfocused focal spot and transmission x-ray target

  14. Ion source development for uranium-logging neutron tube

    International Nuclear Information System (INIS)

    Bacon, F.M.; O'Hagan, J.B.

    1977-03-01

    Ion beam current and mass distributions have been measured for a Penning-type ion source in a uranium-logging neutron tube. For a discharge current of 1 A and gas pressure of 1.3 Pa, the beam current was about 65 mA and the mass distribution was 5 percent D + , 80 percent D 2 + , and 15 percent D 3 + . A demountable version of this source was built to determine how geometry changes could affect the ion beam current and mass distribution. A factor of three increase in beam current was achieved by decreasing the depth of the plasma expansion cup to zero. The only method by which the mass distribution was significantly modified was by dissociating the gas in the source with a hot tungsten filament. Atomic percentage was increased to 40 percent with a filament at about 3000 K

  15. Processing of transmission data from an uncollimated single photon source

    International Nuclear Information System (INIS)

    Dikaios, N.; Dinelle, K.; Spinks, T.; Nikita, K.; Thielemans, K.

    2006-01-01

    The EXACT 3D PET scanner uses a Cs-137 single photon rotating point source for the transmission scan. As the source is un-collimated, the transmission data are contaminated by scatter. It has been suggested that segmentation of the reconstructed image can restore the quantitative information in the image. We study here if the results can be further improved by the application of a scale factor for every transaxial plane

  16. A new method to determine in situ the transmission of a neutron-guide system at a reactor source

    CERN Document Server

    Haan, V O D; Gommers, R M; Labohm, F; Well, A A V; De Leege, P F A; Schebetov, A; Pusenkov, V

    2002-01-01

    In this paper, a description of a new method to determine the transmission of neutron guides after they are installed in a beam-tube at a reactor source is given. The method is based on activation measurements of gold foils at the entrance of the beam-tube and at the exit of the neutron guides compared to Monte-Carlo calculations. In this method, a quality factor is defined as the ratio between the actual transmission and the theoretical maximum attainable transmission. This method is used to determine the quality of an optimised neutron-guide system developed for beam-tube R2 of the HOR. The HOR is a pool-type nuclear research reactor at the Interfaculty Reactor Institute of the Delft University of Technology. It is shown that the quality factors of the newly installed neutron guides are between 0.49 and 0.63.

  17. A new method to determine in situ the transmission of a neutron-guide system at a reactor source

    International Nuclear Information System (INIS)

    Haan, V.O. de; Gibcus, H.P.M.; Gommers, R.M.; Labohm, F.; Well, A.A. van; Leege, P.F.A. de; Schebetov, A.; Pusenkov, V.

    2002-01-01

    In this paper, a description of a new method to determine the transmission of neutron guides after they are installed in a beam-tube at a reactor source is given. The method is based on activation measurements of gold foils at the entrance of the beam-tube and at the exit of the neutron guides compared to Monte-Carlo calculations. In this method, a quality factor is defined as the ratio between the actual transmission and the theoretical maximum attainable transmission. This method is used to determine the quality of an optimised neutron-guide system developed for beam-tube R2 of the HOR. The HOR is a pool-type nuclear research reactor at the Interfaculty Reactor Institute of the Delft University of Technology. It is shown that the quality factors of the newly installed neutron guides are between 0.49 and 0.63

  18. Ion source for thinning of specimen in transmission electron microscopy

    International Nuclear Information System (INIS)

    Hammer, K.; Rothe, R.

    1983-01-01

    Thinning of specimen for transmission electron microscopy is carried out by means of sputtering. Construction, design, and operation parameters of an ion source are presented. Because the plasma is produced by means of hollow cathode glow discharges, no special focusing system is used

  19. YouTube as an information source for pediatric adenotonsillectomy and ear tube surgery.

    Science.gov (United States)

    Sorensen, Jeffrey A; Pusz, Max D; Brietzke, Scott E

    2014-01-01

    Assess the overall quality of information on adenotonsillectomy and ear tube surgery presented on YouTube (www.youtube.com) from the perspective of a parent or patient searching for information on surgery. The YouTube website was systematically searched on select dates with a formal search strategy to identify videos pertaining to pediatric adenotonsillectomy and ear tube surgery. Only videos with at least 5 (ear tube surgery) or 10 (adenotonsillectomy) views per day were included. Each video was viewed and scored by two independent scorers. Videos were categorized by goal and scored for video/audio quality, accuracy, comprehensiveness, and procedure-specific content. Cross-sectional study. Public domain website. Fifty-five videos were scored for adenotonsillectomy and forty-seven for ear tube surgery. The most common category was educational (65.3%) followed by testimonial (28.4%), and news program (9.8%). Testimonials were more common for adenotonsillectomy than ear tube surgery (41.8% vs. 12.8%, p=0.001). Testimonials had a significantly lower mean accuracy (2.23 vs. 2.62, p=0.02), comprehensiveness (1.71 vs. 2.22, p=0.007), and TA specific content (0.64 vs. 1.69, p=0.001) score than educational type videos. Only six videos (5.9%) received high scores in both video/audio quality and accuracy/comprehensiveness of content. There was no significant association between the accuracy and comprehensive score and views, posted "likes", posted "dislikes", and likes/dislikes ratio. There was an association between "likes" and mean video quality (Spearman's rho=0.262, p=0.008). Parents/patients searching YouTube for information on pediatric adenotonsillectomy and ear tube surgery will generally encounter low quality information with testimonials being common but of significantly lower quality. Viewer perceived quality ("likes") did not correlate to formally scored content quality. Published by Elsevier Ireland Ltd.

  20. Subcarrier multiplexing tolerant dispersion transmission system employing optical broadband sources.

    Science.gov (United States)

    Grassi, Fulvio; Mora, José; Ortega, Beatriz; Capmany, José

    2009-03-16

    This paper presents a novel SCM optical transmission system for next-generation WDM-PONs combining broadband optical sources and a Mach-Zehnder interferometric structure. The approach leeds to transport RF signals up to 50 GHz being compatible with RoF systems since a second configuration has been proposed in order to overcome dispersion carrier suppression effect using DSB modulation. The theoretical analysis validates the potentiality of the system also considering the effects of the dispersion slope over the transmission window. (c) 2009 Optical Society of America

  1. Application of an expectation maximization method to the reconstruction of X-ray-tube spectra from transmission data

    International Nuclear Information System (INIS)

    Endrizzi, M.; Delogu, P.; Oliva, P.

    2014-01-01

    An expectation maximization method is applied to the reconstruction of X-ray tube spectra from transmission measurements in the energy range 7–40 keV. A semiconductor single-photon counting detector, ionization chambers and a scintillator-based detector are used for the experimental measurement of the transmission. The number of iterations required to reach an approximate solution is estimated on the basis of the measurement error, according to the discrepancy principle. The effectiveness of the stopping rule is studied on simulated data and validated with experiments. The quality of the reconstruction depends on the information available on the source itself and the possibility to add this knowledge to the solution process is investigated. The method can produce good approximations provided that the amount of noise in the data can be estimated. - Highlights: • An expectation maximization method was used together with the discrepancy principle. • The discrepancy principle is a suitable criterion for stopping the iteration. • The method can be applied to a variety of detectors/experimental conditions. • The minimum information required is the amount of noise that affects the data. • Improved results are achieved by inserting more information when available

  2. YouTube as a source of clinical skills education.

    Science.gov (United States)

    Duncan, Ian; Yarwood-Ross, Lee; Haigh, Carol

    2013-12-01

    YouTube may be viewed as a great 'time waster' but a significant amount of educative material can be found if the user is carefully selective. Interestingly, the growth of educational video on YouTube is closely associated to video viewership which increased from 22% to 38% between 2007 and 2009. This paper describes the findings of a study undertaken to assess the quality of clinical skills videos available on the video sharing site YouTube. This study evaluated 100 YouTube sites, approximately 1500 min or 25 h worth of content across 10 common clinical skill related topics. In consultation with novice practitioners, nurses in the first year of their university diploma programme, we identified ten common clinical skills that typically students would explore in more detail or would wish to revisit outside of the formal teaching environment. For each of these topics, we viewed each of the first 10 videos on the YouTube website. The videos were evaluated using a modification of the criteria outlined in Evaluation of Video Media Guideline. The topic with the biggest number of both postings and views was cardiopulmonary resuscitation and more specialist, nursing or health related topics such as managing a syringe driver or undertaking a pain assessment had less video content and lower numbers of viewers. Only one video out of the 100 analysed could be categorised as 'good' and that was the one in the Cannulation section. 60% of the CPR and venepuncture content was categorised as 'satisfactory'. There is a clear need for the quality of YouTube videos to be subjected to a rigorous evaluation. Lecturers should be more proactive in recommending suitable YouTube material as supplementary learning materials after appropriately checking for quality. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Impact of plasma tube wall thickness on power coupling in ICP sources

    International Nuclear Information System (INIS)

    Nawaz, Anuscheh; Herdrich, Georg

    2009-01-01

    The inductively heated plasma source at the Institute of Space Systems was investigated with respect to the wall thickness of the plasma tube using an air plasma. For this, the wall thickness of the quartz tube was reduced in steps from 2.5 to 1.25 mm. The significance of reducing the wall thickness was analyzed with respect to both the maximum allowable tube cooling power and the coupling efficiency. While the former results from thermal stresses in the tube's wall, the latter results from a minimization of magnetic field losses near the coil turns of the inductively coupled plasma (ICP) source. Analysis of the thermal stress could be validated by experimental data, i.e. the measurement of the tube cooling power when the respective tube structure failed. The coupling efficiency could be assessed qualitatively by simplified models, and the experimental data recorded show that coupling was improved far more than predicted.

  4. Inner surface modification of a tube by magnetic glow-arc plasma source ion implantation

    International Nuclear Information System (INIS)

    Zhang Guling; Chinese Academy of Sciences, Beijing; Wang Jiuli; Feng Wenran; Chen Guangliang; Gu Weichao; Niu Erwu; Fan Songhua; Liu Chizi; Yang Size; Wu Xingfang

    2006-01-01

    A new method named the magnetic glow-arc plasma source ion implantation (MGA-PSII) is proposed for inner surface modification of tubes. In MGA-PSII, under the control of an axial magnetic field, which is generated by an electric coil around the tube sample, glow arc plasma moves spirally into the tube from its two ends. A negative voltage applied on the tube realized its inner surface implantation. Titanium nitride (TiN) films are prepared on the inner surface of a stainless steel tube in diameter 90 mm and length 600 mm. Hardness tests show that the hardness at the tube centre is up to 20 GPa. XRD, XPS and AES analyses demonstrate that good quality of TiN films can be achieved. (authors)

  5. Inner Surface Modification of a Tube by Magnetic Glow-Arc Plasma Source Ion Implantation

    Science.gov (United States)

    Zhang, Gu-Ling; Wang, Jiu-Li; Wu, Xing-Fang; Feng, Wen-Ran; Chen, Guang-Liang; Gu, Wei-Chao; Niu, Er-Wu; Fan, Song-Hua; Liu, Chi-Zi; Yang, Si-Ze

    2006-05-01

    A new method named the magnetic glow-arc plasma source ion implantation (MGA-PSII) is proposed for inner surface modification of tubes. In MGA-PSII, under the control of an axial magnetic field, which is generated by an electric coil around the tube sample, glow arc plasma moves spirally into the tube from its two ends. A negative voltage applied on the tube realized its inner surface implantation. Titanium nitride (TiN) films are prepared on the inner surface of a stainless steel tube in diameter 90 mm and length 600 mm. Hardness tests show that the hardness at the tube centre is up to 20 GPa. XRD, XPS and AES analyses demonstrate that good quality of TiN films can be achieved.

  6. Thermal analysis of a transmission line for Traveling Wave Tube TWT

    International Nuclear Information System (INIS)

    Chbiki, Mounir; Laraqi, Najib; Jarno, Jean-François; Herrewyn, Jacques; Silva Botelho, Tony da

    2012-01-01

    A new analytical method has been developed to study the delay line of Traveling Waves Tubes (TWT). Our study is focused on the analysis of the hot lines shrinking phenomenon. In the studied case, unlike brazed configuration, the contact areas are not perfect, resulting in a diminution of the heat transfer process. In this work, we highlight the influence of the macro-constriction on the heat transfer rate in the various parts of a TWT the geometry of which is also relatively complex. We propose in this work an analytical study of the thermal behavior of a transmission line in established regime. First, we determine the individual thermal resistance of each component. Secondly, we estimate the global resistance of the device according to the geometrical parameters and the respective conductivities of the various elements of this line. In this analytical model, we proceed to parametric studies in order to determine the geometrical configurations that will provide the lowest global thermal resistance. We will emphasize the potential gain according to the used materials and the increase of contact areas.

  7. YouTube as a source of quitting smoking information.

    Science.gov (United States)

    Backinger, Cathy L; Pilsner, Alison M; Augustson, Erik M; Frydl, Andrea; Phillips, Todd; Rowden, Jessica

    2011-03-01

    To conduct analyses to determine the extent to which YouTube videos posted specific to smoking cessation were actually about quitting smoking and if so, whether or not they portrayed evidence-based practices (EBPs). In August 2008, researchers identified YouTube videos by search strategies, 'relevance' and 'view count' using the following three search terms: 'stop smoking', 'quit smoking' and 'smoking cessation (n=296 for full sample and n=191 for unique videos). Overall, almost 60% of videos contained a message about quitting smoking. Differences were found across search terms for videos about quitting smoking, with 'stop smoking' yielding the highest percentage (80.8%) of videos about quitting smoking. Almost half of the videos (48.9%) contained EBPs for cessation strategies; however, a significant portion contained either non--EBPs (28.4%) or both EBPs and non-EBPs (22.7%). The number of views per an individual video across the six categories ranged from a low of 8 in the 'relevance' strategy and 'smoking cessation' search term to a high of 1,247,540 in the 'view count' strategy and 'stop smoking' search term. Of the top three most viewed videos by strategy and search term, 66.7% included a specific mention of quitting smoking and, of these, the majority included EBPs. Results highlight the need to develop and upload videos containing EBPs both to increase the overall proportion of EBP videos in all categories, particularly in 'quit smoking' and 'stop smoking.' Research is needed to study whether YouTube videos influence knowledge, attitudes and behaviours regarding quitting smoking.

  8. YouTube as a Source of Information on Neurosurgery.

    Science.gov (United States)

    Samuel, Nardin; Alotaibi, Naif M; Lozano, Andres M

    2017-09-01

    The importance of videos in social media communications in the context of health care and neurosurgery is becoming increasingly recognized. However, there has not yet been a systematic analysis of these neurosurgery-related communications. Accordingly, this study was aimed at characterizing the online video content pertaining to neurosurgery. Neurosurgery-related videos uploaded on YouTube were collected using a comprehensive search strategy. The following metrics were extracted for each video: number of views, likes, dislikes, comments, shares, date of upload, and geographic region of origin where specified. A quantitative and qualitative evaluation was performed on all videos included in the study. A total of 713 nonduplicate videos met the inclusion criteria. The overall number of views for all videos was 90,545,164. Videos were most frequently uploaded in 2016 (n = 348), with a 200% increase in uploads compared with the previous year. Of the videos that were directly relevant to clinical neurosurgery, the most frequent video categories were "educational videos" (25%), followed by "surgical and procedure overview" (20%), "promotional videos" (17%), and "patient experience" (16%). The remainder of the videos consisted primarily of unrealistic simulations of cranial surgery for entertainment purposes (20%). The findings from this study highlight the increasing use of video communications related to neurosurgery and show that institutions, neurosurgeons, and patients are using YouTube as an educational and promotional platform. As online communications continue to evolve, it will be important to harness this tool to advance patient-oriented communication and knowledge dissemination in neurosurgery. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Determination of tungsten target parameters for transmission X-ray tube: A simulation study using Geant4

    Energy Technology Data Exchange (ETDEWEB)

    Nasseri, Mohammad M. [School of Plasma Physics and Nuclear Fusion, Institute of Nuclear Science and Technology (AEOI), Tehran (Iran, Islamic Republic of)

    2016-06-15

    Transmission X-ray tubes based on carbon nanotube have attracted significant attention recently. In most of these tubes, tungsten is used as the target material. In this article, the well-known simulator Geant4 was used to obtain some of the tungsten target parameters. The optimal thickness for maximum production of usable X-rays when the target is exposed to electron beams of different energies was obtained. The linear variation of optimal thickness of the target for different electron energies was also obtained. The data obtained in this study can be used to design X-ray tubes. A beryllium window was considered for the X-ray tube. The X-ray energy spectra at the moment of production and after passing through the target and window for different electron energies in the 30-110 keV range were also obtained. The results obtained show that with a specific thickness, the target material itself can act as filter, which enables generation of X-rays with a limited energy.

  10. Optimum transmission system expansion offshore considering renewable energy sources

    NARCIS (Netherlands)

    Torbaghan, Shahab S.; Gibescu, Madeleine

    2017-01-01

    This chapter provides an overview of transmission expansion planning (TEP) methods and their practical application. First, it discusses the strategic importance of the transmission system. Next, it describes the reasons why TEP remains a challenge for systems with a large share of renewable energy.

  11. Coupling an electrospray source and a solids probe/chemical ionization source to a selected ion flow tube apparatus

    International Nuclear Information System (INIS)

    Melko, Joshua J.; Ard, Shaun G.; Shuman, Nicholas S.; Viggiano, Albert A.; Pedder, Randall E.; Taormina, Christopher R.

    2015-01-01

    A new ion source region has been constructed and attached to a variable temperature selected ion flow tube. The source features the capabilities of electron impact, chemical ionization, a solids probe, and electrospray ionization. The performance of the instrument is demonstrated through a series of reactions from ions created in each of the new source regions. The chemical ionization source is able to create H 3 O + , but not as efficiently as similar sources with larger apertures. The ability of this source to support a solids probe, however, greatly expands our capabilities. A variety of rhenium cations and dications are created from the solids probe in sufficient abundance to study in the flow tube. The reaction of Re + with O 2 proceeds with a rate constant that agrees with the literature measurements, while the reaction of Re 2 2+ is found to charge transfer with O 2 at about 60% of the collision rate; we have also performed calculations that support the charge transfer pathway. The electrospray source is used to create Ba + , which is reacted with N 2 O to create BaO + , and we find a rate constant that agrees with the literature

  12. Radiation transport calculations for the ANS [Advanced Neutron Source] beam tubes

    International Nuclear Information System (INIS)

    Engle, W.W. Jr.; Lillie, R.A.; Slater, C.O.

    1988-01-01

    The Advanced Neutron Source facility (ANS) will incorporate a large number of both radial and no-line-of-sight (NLS) beam tubes to provide very large thermal neutron fluxes to experimental facilities. The purpose of this work was to obtain comparisons for the ANS single- and split-core designs of the thermal and damage neutron and gamma-ray scalar fluxes in these beams tubes. For experimental locations far from the reactor cores, angular flux data are required; however, for close-in experimental locations, the scalar fluxes within each beam tube provide a credible estimate of the various signal to noise ratios. In this paper, the coupled two- and three-dimensional radiation transport calculations employed to estimate the scalar neutron and gamma-ray fluxes will be described and the results from these calculations will be discussed. 6 refs., 2 figs

  13. YouTube videos as a source of medical information during the Ebola hemorrhagic fever epidemic.

    Science.gov (United States)

    Nagpal, Sajan Jiv Singh; Karimianpour, Ahmadreza; Mukhija, Dhruvika; Mohan, Diwakar; Brateanu, Andrei

    2015-01-01

    The content and quality of medical information available on video sharing websites such as YouTube is not known. We analyzed the source and quality of medical information about Ebola hemorrhagic fever (EHF) disseminated on YouTube and the video characteristics that influence viewer behavior. An inquiry for the search term 'Ebola' was made on YouTube. The first 100 results were arranged in decreasing order of "relevance" using the default YouTube algorithm. Videos 1-50 and 51-100 were allocated to a high relevance (HR), and a low relevance (LR) video group, respectively. Multivariable logistic regression models were used to assess the predictors of a video being included in the HR vs. LR groups. Fourteen videos were excluded because they were parodies, songs or stand-up comedies (n = 11), not in English (n = 2) or a remaining part of a previous video (n = 1). Two scales, the video information and quality and index and the medical information and content index (MICI) assessed the overall quality, and the medical content of the videos, respectively. There were no videos from hospitals or academic medical centers. Videos in the HR group had a higher median number of views (186,705 vs. 43,796, p YouTube videos presenting clinical symptoms of infectious diseases during epidemics are more likely to be included in the HR group and influence viewers behavior.

  14. YouTube is the Most Frequently Used Educational Video Source for Surgical Preparation.

    Science.gov (United States)

    Rapp, Allison K; Healy, Michael G; Charlton, Mary E; Keith, Jerrod N; Rosenbaum, Marcy E; Kapadia, Muneera R

    The purpose of this study was to evaluate surgical preparation methods of medical students, residents, and faculty with special attention to video usage. Following Institutional Review Board approval, anonymous surveys were distributed to participants. Information collected included demographics and surgical preparation methods, focusing on video usage. Participants were questioned regarding frequency and helpfulness of videos, video sources used, and preferred methods between videos, reading, and peer consultation. Statistical analysis was performed using SAS. Surveys were distributed to participants in the Department of Surgery at the University of Iowa Hospitals and Clinics, a tertiary care center in Iowa City, Iowa. Survey participants included fourth-year medical students pursuing general surgery, general surgery residents, and faculty surgeons in the Department of Surgery. A total of 86 surveys were distributed, and 78 surveys were completed. This included 42 learners (33 residents, 9 fourth-year medical students) and 36 faculty. The overall response rate was 91%; 90% of respondents reported using videos for surgical preparation (learners = 95%, faculty = 83%, p = NS). Regarding surgical preparation methods overall, most learners and faculty selected reading (90% versus 78%, p = NS), and fewer respondents reported preferring videos (64% versus 44%, p = NS). Faculty more often use peer consultation (31% versus 50%, p YouTube (86%). Learners and faculty use different video sources. Learners use YouTube and Surgical Council on Resident Education (SCORE) Portal more than faculty (YouTube: 95% versus 73%, p YouTube was the preferred source. Posting surgical videos to YouTube may allow for maximal access to learners who are preparing for surgical cases. Copyright © 2016 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  15. YouTube as a source of information on mouth (oral) cancer.

    Science.gov (United States)

    Hassona, Y; Taimeh, D; Marahleh, A; Scully, C

    2016-04-01

    We examined the content of YouTube(™) videos on mouth (oral) cancer and evaluated their usefulness in promoting early detection of oral cancer. A systematic search of YouTube(™) for videos containing information on mouth cancer was conducted using the keywords 'mouth cancer' and 'oral cancer'. Demographics of videos, including type, source, length, and viewers' interaction, were evaluated, and three researchers independently assessed the videos for usefulness in promoting early detection of oral cancer. A total of 188 YouTube(™) videos (152 patient-oriented educational videos and 36 testimonial videos) were analyzed. The overall usefulness score ranged from 0 to 10 (mean = 3.56 ± 2.44). The most useful videos ranked late on the viewing list, and there was no significant correlation between video usefulness and viewing rate, viewers' interaction, and video length. Videos uploaded by individual users were less useful compared with videos uploaded by professional organizations or by healthcare professionals. Healthcare professionals, academic institutions, and professional organizations have a responsibility for improving the content of YouTube(™) about mouth cancer by uploading useful videos, and directing patients to reliable information sources. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. YouTube as a Source of Information on Ebola Virus Disease.

    Science.gov (United States)

    Pathak, Ranjan; Poudel, Dilli Ram; Karmacharya, Paras; Pathak, Amrit; Aryal, Madan Raj; Mahmood, Maryam; Donato, Anthony A

    2015-07-01

    The current West Africa epidemic of Ebola virus disease (EVD), which began from Guinea in December 2013, has been the longest and deadliest Ebola outbreak to date. With the propagation of the internet, public health officials must now compete with other official and unofficial sources of information to get their message out. This study aimed at critically appraising videos available on one popular internet video site (YouTube) as a source of information for Ebola virus disease (EVD). Videos were searched in YouTube (http://www.youtube.com) using the keyword "Ebola outbreak" from inception to November 1, 2014 with the default "relevance" filter. Only videos in English language under 10 min duration within first 10 pages of search were included. Duplicates were removed and the rest were classified as useful or misleading by two independent reviewers. Video sources were categorized by source. Inter-observer agreement was evaluated with kappa coefficient. Continuous and categorical variables were analyzed using the Student t-test and Chi-squared test, respectively. One hundred and eighteen out of 198 videos were evaluated. Thirty-one (26.27%) videos were classified as misleading and 87 (73.73%) videos were classified as useful. The kappa coefficient of agreement regarding the usefulness of the videos was 0.68 (P YouTube were characterized as useful. Although YouTube seems to generally be a useful source of information on the current outbreak, increased efforts to disseminate scientifically correct information is desired to prevent unnecessary panic among the among the general population.

  17. Effectiveness of YouTube as a Source of Medical Information on Heart Transplantation.

    Science.gov (United States)

    Chen, He-Ming; Hu, Zhong-Kai; Zheng, Xiao-Lin; Yuan, Zhao-Shun; Xu, Zhao-Bin; Yuan, Ling-Qing; Perez, Vinicio A De Jesus; Yuan, Ke; Orcholski, Mark; Liao, Xiao-Bo

    2013-11-21

    In this digital era, there is a growing tendency to use the popular Internet site YouTube as a new electronic-learning (e-learning) means for continuing medical education. Heart transplantation (HTx) remains the most viable option for patients with end-stage heart failure or severe coronary artery disease. There are plenty of freely accessible YouTube videos providing medical information about HTx. The aim of the present study is to determine the effectiveness of YouTube as an e-learning source on HTx. In order to carry out this study, YouTube was searched for videos uploaded containing surgical-related information using the four keywords: (1) "heart transplantation", (2) "cardiac transplantation", (3) "heart transplantation operation", and (4) "cardiac transplantation operation". Only videos in English (with comments or subtitles in English language) were included. Two experienced cardiac surgeons watched each video (N=1800) and classified them as useful, misleading, or recipients videos based on the HTx-relevant information. The kappa statistic was used to measure interobserver variability. Data was analyzed according to six types of YouTube characteristics including "total viewership", "duration", "source", "days since upload", "scores" given by the viewers, and specialized information contents of the videos. A total of 342/1800 (19.00%) videos had relevant information about HTx. Of these 342 videos, 215 (62.8%) videos had useful information about specialized knowledge, 7/342 (2.0%) were found to be misleading, and 120/342 (35.1%) only concerned recipients' individual issues. Useful videos had 56.09% of total viewership share (2,175,845/3,878,890), whereas misleading had 35.47% (1,375,673/3,878,890). Independent user channel videos accounted for a smaller proportion (19% in total numbers) but might have a wider impact on Web viewers, with the highest mean views/day (mean 39, SD 107) among four kinds of channels to distribute HTx-related information. YouTube

  18. YouTube as a source of COPD patient education: A social media content analysis

    Science.gov (United States)

    Stellefson, Michael; Chaney, Beth; Ochipa, Kathleen; Chaney, Don; Haider, Zeerak; Hanik, Bruce; Chavarria, Enmanuel; Bernhardt, Jay M.

    2014-01-01

    Objective Conduct a social media content analysis of COPD patient education videos on YouTube. Methods A systematic search protocol was used to locate 223 videos. Two independent coders evaluated each video to determine topics covered, media source(s) of posted videos, information quality as measured by HONcode guidelines for posting trustworthy health information on the Internet, and viewer exposure/engagement metrics. Results Over half the videos (n=113, 50.7%) included information on medication management, with far fewer videos on smoking cessation (n=40, 17.9%). Most videos were posted by a health agency or organization (n=128, 57.4%), and the majority of videos were rated as high quality (n=154, 69.1%). HONcode adherence differed by media source (Fisher’s Exact Test=20.52, p=.01), with user-generated content (UGC) receiving the lowest quality scores. Overall level of user engagement as measured by number of “likes,” “favorites,” “dislikes,” and user comments was low (mdn range = 0–3, interquartile (IQR) range = 0–16) across all sources of media. Conclusion Study findings suggest that COPD education via YouTube has the potential to reach and inform patients, however, existing video content and quality varies significantly. Future interventions should help direct individuals with COPD to increase their engagement with high-quality patient education videos on YouTube that are posted by reputable health organizations and qualified medical professionals. Patients should be educated to avoid and/or critically view low-quality videos posted by individual YouTube users who are not health professionals. PMID:24659212

  19. YouTube as a patient-information source for root canal treatment.

    Science.gov (United States)

    Nason, K; Donnelly, A; Duncan, H F

    2016-12-01

    To assess the content and completeness of Youtube ™ as an information source for patients undergoing root canal treatment procedures. YouTube ™ (https://www.youtube.com/) was searched for information using three relevant treatment search terms ('endodontics', 'root canal' and 'root canal treatment'). After exclusions (language, no audio, >15 min, duplicates), 20 videos per search term were selected. General video assessment included duration, ownership, views, age, likes/dislikes, target audience and video/audio quality, whilst content was analysed under six categories ('aetiology', 'anatomy', 'symptoms', 'procedure', 'postoperative course' and 'prognosis'). Content was scored for completeness level and statistically analysed using anova and post hoc Tukey's test (P YouTube ™ videos for endodontic search terms varied significantly by source and content and were generally incomplete. The danger of patient reliance on YouTube ™ is highlighted, as is the need for endodontic professionals to play an active role in directing patients towards alternative high-quality information sources. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  20. Measurement of electron beams profile of pierce type electron source using sensor of used Tv tube

    International Nuclear Information System (INIS)

    Darsono; Suhartono; Suprapto; Elin Nuraini

    2015-01-01

    The measurement of an electron beam profile has been performed using electron beam monitor based on method of phosphorescent materials. The main components of the electron beam monitor consists of a fluorescent sensor using a used Tv tube, CCTV camera to record images on a Tv screen, video adapter as interface between CCTV and laptop, and the laptop as a viewer and data processing. Two Pierce-type electron sources diode and triode was measured the shape of electron beam profile in real time. Results of the experiments showed that the triode electron source of Pierce type gave the shape of electron beam profiles better than that of the diode electron source .The anode voltage is not so influential on the beam profile shape. The focused voltage in the triode electron source is so influence to the shape of the electron beam profile, but above 5 kV no great effect. It can be concluded that the electron beam monitor can provide real time observations and drawings shape of the electron beam profile displayed on the used Tv tube glass screen which is the real picture of the shape of the electron beam profile. Triode electron source produces a better electron beam profile than that of the diode electron source. (author)

  1. Integrating a Traveling Wave Tube into an AECR-U ion source

    Energy Technology Data Exchange (ETDEWEB)

    Covo, Michel Kireeff; Benitez, Janilee Y.; Ratti, Alessandro; Vujic, Jasmina L.

    2011-07-01

    An RF system of 500W - 10.75 to 12.75 GHz was designed and integrated into the Advanced Electron Cyclotron Resonance - Upgrade (AECR-U) ion source of the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory. The AECR-U produces ion beams for the Cyclotron giving large flexibility of ion species and charge states. The broadband frequency of a Traveling Wave Tube (TWT) allows modifying the volume that couples and heats the plasma. The TWT system design and integration with the AECR-U ion source and results from commissioning are presented.

  2. Improved transmission of electrostatic accelerator in a wide range of terminal voltages by controlling the focal strength of entrance acceleration tube

    Science.gov (United States)

    Lobanov, Nikolai R.; Tunningley, Thomas; Linardakis, Peter

    2018-04-01

    Tandem electrostatic accelerators often require the flexibility to operate at a variety of terminal voltages to accommodate various user requirements. However, the ion beam transmission will only be optimal for a limited range of terminal voltages. This paper describes the operational performance of a novel focusing system that expands the range of terminal voltages for optimal transmission. This is accomplished by controlling the gradient of the entrance of the low-energy tube, providing an additional focusing element. In this specific case it is achieved by applying up to 150 kV to the fifth electrode of the first unit of the accelerator tube. Numerical simulations and beam transmission tests have been performed to confirm the effectiveness of the lens. An analytical expression has been derived describing its focal properties. These tests demonstrate that the entrance lens control eliminates the need to short out sections of the tube for operation at low terminal voltage.

  3. YouTube as a source of information on skin bleaching: a content analysis.

    Science.gov (United States)

    Basch, C H; Brown, A A; Fullwood, M D; Clark, A; Fung, I C-H; Yin, J

    2018-06-01

    Skin bleaching is a common, yet potentially harmful body modification practice. To describe the characteristics of the most widely viewed YouTube™ videos related to skin bleaching. The search term 'skin bleaching' was used to identify the 100 most popular English-language YouTube videos relating to the topic. Both descriptive and specific information were noted. Among the 100 manually coded skin-bleaching YouTube videos in English, there were 21 consumer-created videos, 45 internet-based news videos, 30 television news videos and 4 professional videos. Excluding the 4 professional videos, we limited our content categorization and regression analysis to 96 videos. Approximately 93% (89/96) of the most widely viewed videos mentioned changing how you look and 74% (71/96) focused on bleaching the whole body. Of the 96 videos, 63 (66%) of videos showed/mentioned a transformation. Only about 14% (13/96) mentioned that skin bleaching is unsafe. The likelihood of a video selling a skin bleaching product was 17 times higher in internet videos compared with consumer videos (OR = 17.00, 95% CI 4.58-63.09, P YouTube video on skin bleaching was uploaded by an internet source. Videos made by television sources mentioned more information about skin bleaching being unsafe, while consumer-generated videos focused more on making skin-bleaching products at home. © 2017 British Association of Dermatologists.

  4. Assessment of YouTube videos as a source of information on medication use in pregnancy.

    Science.gov (United States)

    Hansen, Craig; Interrante, Julia D; Ailes, Elizabeth C; Frey, Meghan T; Broussard, Cheryl S; Godoshian, Valerie J; Lewis, Courtney; Polen, Kara N D; Garcia, Amanda P; Gilboa, Suzanne M

    2016-01-01

    When making decisions about medication use in pregnancy, women consult many information sources, including the Internet. The aim of this study was to assess the content of publicly accessible YouTube videos that discuss medication use in pregnancy. Using 2023 distinct combinations of search terms related to medications and pregnancy, we extracted metadata from YouTube videos using a YouTube video Application Programming Interface. Relevant videos were defined as those with a medication search term and a pregnancy-related search term in either the video title or description. We viewed relevant videos and abstracted content from each video into a database. We documented whether videos implied each medication to be "safe" or "unsafe" in pregnancy and compared that assessment with the medication's Teratogen Information System (TERIS) rating. After viewing 651 videos, 314 videos with information about medication use in pregnancy were available for the final analyses. The majority of videos were from law firms (67%), television segments (10%), or physicians (8%). Selective serotonin reuptake inhibitors (SSRIs) were the most common medication class named (225 videos, 72%), and 88% of videos about SSRIs indicated that they were unsafe for use in pregnancy. However, the TERIS ratings for medication products in this class range from "unlikely" to "minimal" teratogenic risk. For the majority of medications, current YouTube video content does not adequately reflect what is known about the safety of their use in pregnancy and should be interpreted cautiously. However, YouTube could serve as a platform for communicating evidence-based medication safety information. Copyright © 2015 John Wiley & Sons, Ltd.

  5. YouTube as a source of patient information on gallstone disease.

    Science.gov (United States)

    Lee, Jun Suh; Seo, Ho Seok; Hong, Tae Ho

    2014-04-14

    To investigate the quality of YouTube videos on gallstone disease and to assess viewer response according to quality. A YouTube search was performed on September 18, 2013, using the keywords ''gallbladder disease'', ''gallstone disease'', and ''gallstone treatment''. Three researchers assessed the source, length, number of views, number of likes, and days since upload. The upload source was categorised as physician or hospital (PH), medical website or TV channel, commercial website (CW), or civilian. A usefulness score was devised to assess video quality and to categorise the videos into ''very useful'', ''useful'', ''slightly useful'', or ''not useful''. Videos with misleading content were categorised as ''misleading''. One hundred and thirty-one videos were analysed. Seventy-four videos (56.5%) were misleading, 36 (27.5%) were slightly useful, 15 (11.5%) were useful, three (2.3%) were very useful, and three (2.3%) were not useful. The number of mean likes (1.3 ± 1.5 vs 17.2 ± 38.0, P = 0.007) and number of views (756.3 ± 701.0 vs 8910.7 ± 17094.7, P = 0.001) were both significantly lower in the very useful group compared with the misleading group. All three very useful videos were PH videos. Among the 74 misleading videos, 64 (86.5%) were uploaded by a CW. There was no correlation between usefulness and the number of views, the number of likes, or the length. The "gallstone flush" was the method advocated most frequently by misleading videos (25.7%). More than half of the YouTube videos on gallstone disease are misleading. Credible videos uploaded by medical professionals and filtering by the staff of YouTube appear to be necessary.

  6. Identification of pulse echo impulse responses for multi source transmission

    DEFF Research Database (Denmark)

    Gran, Fredrik; Jensen, Jørgen Arendt

    2004-01-01

    is a mixture of the information corresponding to several transmitters. There is, thus, no direct way of determining which information corresponds to which transmitter, preventing proper focusing. In this paper we decode the received signal by estimating the pulse echo impulse responses between every....... The method is evaluated using the simulation tool Field II. Three point spread functions are simulated where axial movement of 1 m/s is present. The axial resolution for the moving scatterer is 0.249 mm (-3dB) and 0.291 mm (-6dB), which is compared to a standard STA transmission scheme with sequential...

  7. YouTube as a source of information for obstructive sleep apnea.

    Science.gov (United States)

    Singh, Sameer K; Liu, Stanley; Capasso, Robson; Kern, Robert C; Gouveia, Christopher J

    Assess the quality of information on obstructive sleep apnea (OSA) presented on YouTube for patients. "Obstructive sleep apnea" was entered into the YouTube search. Two independent reviewers categorized and analyzed videos utilizing a customized scoring-system along with search position, likes, and views. Forty-eight videos were analyzed. Most were educational (52.1%). Educational and news videos had significantly higher scores, but had no significant differences in search position, likes/day, or views/day. Most videos mentioned positive airway pressure (65%), and nearly half (44%) mentioned mandibular devices in the management of OSA. Few videos discussed surgery (13%) or otolaryngology (15%). YouTube is a promising source of information for OSA patients. Educational and news videos are of highest quality. General quality measures like search position, views, and likes are not correlated with formally scored value. Sleep surgery and otolaryngologists are minimally mentioned, representing an opportunity for improvement. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. YouTube as a Source of Information on Cervical Cancer.

    Science.gov (United States)

    Adhikari, Janak; Sharma, Priyadarshani; Arjyal, Lubina; Uprety, Dipesh

    2016-04-01

    Cervical cancer is the third most common cancer worldwide. Accurate information about cervical cancer to general public can lower the burden of the disease including its mortality. We aimed to look at the quality of information available in YouTube for cervical cancer. We searched YouTube (http://www.youtube.com) for videos using the keyword Cervical cancer on November 12, 2015. Videos were then analyzed for their source and content of information. We studied 172 videos using the keyword Cervical cancer on November 12, 2015. We found that there were videos describing the personal stories, risk factors, and the importance of screening. However, videos discussing all the aspects of cancers were lacking. Likewise, videos from the reputed organization were also lacking. Although there were numerous videos available in cervical cancer, videos from reputed organizations including Center for Disease Control and Prevention, American Cancer Society, and World Health Organization were lacking. We strongly believe that quality videos from such organizations via YouTube can help lower the burden of disease.

  9. Magnetic shielding of an inhomogeneous magnetic field source by a bulk superconducting tube

    International Nuclear Information System (INIS)

    Hogan, K; Fagnard, J-F; Wéra, L; Vanderheyden, B; Vanderbemden, P

    2015-01-01

    Bulk type-II irreversible superconductors can act as excellent passive magnetic shields, with a strong attenuation of low frequency magnetic fields. Up to now, the performances of superconducting magnetic shields have mainly been studied in a homogenous magnetic field, considering only immunity problems, i.e. when the field is applied outside the tube and the inner field should ideally be zero. In this paper, we aim to investigate experimentally and numerically the magnetic response of a high-T c bulk superconducting hollow cylinder at 77 K in an emission problem, i.e. when subjected to the non-uniform magnetic field generated by a source coil placed inside the tube. A bespoke 3D mapping system coupled with a three-axis Hall probe is used to measure the magnetic flux density distribution outside the superconducting magnetic shield. A finite element model is developed to understand how the magnetic field penetrates into the superconductor and how the induced superconducting shielding currents flow inside the shield in the case where the emitting coil is placed coaxially inside the tube. The finite element modelling is found to be in excellent agreement with the experimental data. Results show that a concentration of the magnetic flux lines occurs between the emitting coil and the superconducting screen. This effect is observed both with the modelling and the experiment. In the case of a long tube, we show that the main features of the field penetration in the superconducting walls can be reproduced with a simple analytical 1D model. This model is used to estimate the maximum flux density of the emitting coil that can be shielded by the superconductor. (paper)

  10. Image transmission system using adaptive joint source and channel decoding

    Science.gov (United States)

    Liu, Weiliang; Daut, David G.

    2005-03-01

    In this paper, an adaptive joint source and channel decoding method is designed to accelerate the convergence of the iterative log-dimain sum-product decoding procedure of LDPC codes as well as to improve the reconstructed image quality. Error resilience modes are used in the JPEG2000 source codec, which makes it possible to provide useful source decoded information to the channel decoder. After each iteration, a tentative decoding is made and the channel decoded bits are then sent to the JPEG2000 decoder. Due to the error resilience modes, some bits are known to be either correct or in error. The positions of these bits are then fed back to the channel decoder. The log-likelihood ratios (LLR) of these bits are then modified by a weighting factor for the next iteration. By observing the statistics of the decoding procedure, the weighting factor is designed as a function of the channel condition. That is, for lower channel SNR, a larger factor is assigned, and vice versa. Results show that the proposed joint decoding methods can greatly reduce the number of iterations, and thereby reduce the decoding delay considerably. At the same time, this method always outperforms the non-source controlled decoding method up to 5dB in terms of PSNR for various reconstructed images.

  11. Conjugated heat transfer of natural convection in pool with internal heat sources and convection in the tube

    International Nuclear Information System (INIS)

    Li Longjian; Liu Hongtao; Cui Wenzhi

    2007-01-01

    The conjugated heat transfer of natural convection in pool with internal heat source and the forced convection in the tube was analyzed, and the corresponding three-dimensional physical and mathematical model was proposed. A control volume based finite element method was employed to solve numerically the problem. The computations were performed for different internal heat source intensity of the pool and the different flow velocity in the tube. The computed heat transfer coefficients on the inner and outer wall showed well consistency of those calculated with the empirical correlations. Compared with the measured total heat transfer coefficients between the fluids in and out of the tube, the computed ones showed also the well consistency, which implied that the numerical model proposed in this paper was reliable. The research results revealed that the total heat transfer coefficients between the fluids were strongly affected by the internal heat source intensity of the pool liquid and the flow velocity in the tube. (authors)

  12. Transmission grid requirements with scattered and flutuating renewable electricity sources

    DEFF Research Database (Denmark)

    Østergaard, Poul Alberg

    2002-01-01

    Denmark is in a situation with many scattered sources of electricity, that are not controlled by the central load dispatch. At the same time, Denmark is being used as an electricity transit corridor between Norway/Sweden and Germany. Through energy systems analyses and load-flow analyses......, it is determined that if scattered load balancing is introduced, electricity transit is enabled to a higher degree than if central load balancing is maintained....

  13. SU-F-T-24: Impact of Source Position and Dose Distribution Due to Curvature of HDR Transfer Tubes

    Energy Technology Data Exchange (ETDEWEB)

    Khan, A; Yue, N [Rutgers University, New Brunswick, NJ (United States)

    2016-06-15

    Purpose: Brachytherapy is a highly targeted from of radiotherapy. While this may lead to ideal dose distributions on the treatment planning system, a small error in source location can lead to change in the dose distribution. The purpose of this study is to quantify the impact on source position error due to curvature of the transfer tubes and the impact this may have on the dose distribution. Methods: Since the source travels along the midline of the tube, an estimate of the positioning error for various angles of curvature was determined using geometric properties of the tube. Based on the range of values a specific shift was chosen to alter the treatment plans for a number of cervical cancer patients who had undergone HDR brachytherapy boost using tandem and ovoids. Impact of dose to target and organs at risk were determined and checked against guidelines outlined by radiation oncologist. Results: The estimate of the positioning error was 2mm short of the expected position (the curved tube can only cause the source to not reach as far as with a flat tube). Quantitative impact on the dose distribution is still in the process of being analyzed. Conclusion: The accepted positioning tolerance for the source position of a HDR brachytherapy unit is plus or minus 1mm. If there is an additional 2mm discrepancy due to tube curvature, this can result in a source being 1mm to 3mm short of the expected location. While we do always attempt to keep the tubes straight, in some cases such as with tandem and ovoids, the tandem connector does not extend as far out from the patient so the ovoid tubes always contain some degree of curvature. The dose impact of this may be significant.

  14. Analysis of YouTube as a source of information for West Nile Virus infection.

    Science.gov (United States)

    Dubey, Divyanshu; Amritphale, Amod; Sawhney, Anshudha; Dubey, Devashish; Srivastav, Nupur

    2014-12-01

    A major outbreak of West Nile Virus was seen last year in different parts of the United States. Adequate dissemination of correct information about the disease would have helped decrease its spread and the associated panic in the general population. In this study, we looked into the use of YouTube as a resource for providing information about West Nile Virus infection. This study aims to identify and evaluate YouTube as resource for providing information on West Nile Virus infection to the general public. YouTube was searched on November 25, 2012, using the keywords West Nile Virus epidemic, West Nile Virus infection, and West Nile Virus prevention for videos uploaded in the past 6 months containing relevant information about the disease. The videos were classified as useful, misleading, or as news updates based on the type of information contained. Total viewership, number of days since upload, total duration of videos, and source of upload were noted. A total of 106 videos with information on West Nile Virus infection were included in the study, with 79.24% having useful information about the disease. Among the useful videos, 51/84 (60.71%) had information on disease prevention, and 29/84 (34.52%) contained information on news and research updates. The majority of these videos were uploaded by individuals (54.6%) or news agencies (41.8 %). Healthcare agencies contributed only 3.4 % of the total videos. Even though the useful videos represented 72% of all videos, there was significantly higher total viewership and viewership per day for the non-useful videos (PYouTube may be a significant resource for dissemination of information on public health issues like West Nile virus infection and should be targeted by healthcare agencies for this use. The major drawback of this medium is lack of verification by authorized healthcare professionals before these videos are made available for viewing by the community. Hence, a strict caution should be exercised in obtaining

  15. Rumors about cancer: content, sources, coping, transmission, and belief.

    Science.gov (United States)

    DiFonzo, Nicholas; Robinson, Nicole M; Suls, Jerry M; Rini, Christine

    2012-01-01

    Using a sense-making and threat management framework in rumor psychology, the authors used an exploratory web survey (n = 169) to query members of online cancer discussion groups about informal cancer statements heard from nonmedical sources (i.e., cancer rumors). Respondents perceived that rumors helped them cope. Dread rumors exceeded wish rumors; secondary control (control through emotional coping) rumors outnumbered primary control (direct action) rumors. Rumor content focused on cancer lethality, causes, and suffering. Rumors came primarily from family or friends in face-to-face conversations. Respondents discussed rumors with medical personnel primarily for fact-finding purposes, but with nonmedical people for altruistic, emotional coping, or relationship enhancement motives. Transmitters (vs. nontransmitters) considered rumors to be more important, were more anxious, and felt rumors helped them cope better, but did not believe them more strongly or feel that they were less knowledgeable about cancer. Most respondents believed the rumors; confidence was based on trust in family or friends (disregarding source nonexpertise) and concordance with beliefs, attitudes, and experience. Results point toward the fruitfulness of using rumor theory to guide research on cancer rumors and suggest that rumors help people achieve a sense of emotional control for dreaded cancer outcomes, inform the social construction of cancer, and highlight the continuing importance of nonelectronic word of mouth.

  16. Performance of water source heat pump system using high-density polyethylene tube heat exchanger wound with square copper wire

    Directory of Open Access Journals (Sweden)

    Xin Wen Zhang

    2015-07-01

    Full Text Available Surface water source heat pump system is an energy-efficient heat pump system. Surface water heat exchanger is an important part of heat pump system that can affect the performance of the system. In order to enhance the performance of the system, the overall heat transfer coefficient (U value of the water exchanger using a 32A square copper coiled high-density polyethylene tube was researched. Comparative experiments were conducted between the performance of the coiled high-density polyethylene tube and the 32A smooth high-density polyethylene tube. At the same time, the coefficient of performance of the heat pump was investigated. According to the result, the U value of the coiled tube was 18% higher than that of the smooth tube in natural convection and 19% higher in forced convection. The coefficient of performance of the heat pump with the coiled tube is higher than that with the smooth tube. The economic evaluation of the coiled tube was also investigated.

  17. Zika Virus on YouTube: An Analysis of English-language Video Content by Source

    Directory of Open Access Journals (Sweden)

    Corey H. Basch

    2017-03-01

    Full Text Available Objectives The purpose of this study was to describe the source, length, number of views, and content of the most widely viewed Zika virus (ZIKV-related YouTube videos. We hypothesized that ZIKV-related videos uploaded by different sources contained different content. Methods The 100 most viewed English ZIKV-related videos were manually coded and analyzed statistically. Results Among the 100 videos, there were 43 consumer-generated videos, 38 Internet-based news videos, 15 TV-based news videos, and 4 professional videos. Internet news sources captured over two-thirds of the total of 8 894 505 views. Compared with consumer-generated videos, Internet-based news videos were more likely to mention the impact of ZIKV on babies (odds ratio [OR], 6.25; 95% confidence interval [CI], 1.64 to 23.76, the number of cases in Latin America (OR, 5.63; 95% CI, 1.47 to 21.52; and ZIKV in Africa (OR, 2.56; 95% CI, 1.04 to 6.31. Compared with consumer-generated videos, TV-based news videos were more likely to express anxiety or fear of catching ZIKV (OR, 6.67; 95% CI, 1.36 to 32.70; to highlight fear of ZIKV among members of the public (OR, 7.45; 95% CI, 1.20 to 46.16; and to discuss avoiding pregnancy (OR, 3.88; 95% CI, 1.13 to 13.25. Conclusions Public health agencies should establish a larger presence on YouTube to reach more people with evidence-based information about ZIKV.

  18. Performance Analysis of a Voltage Source Converter (VSC based HVDC Transmission System under Faulted Conditions

    Directory of Open Access Journals (Sweden)

    Amiri RABIE

    2009-12-01

    Full Text Available Voltage Source Converter (VSC based HVDC transmission technology hasbeen selected as the basis for several recent projects due to its controllability,compact modular design, ease of system interface, and low environmentalimpact. This paper investigates the dynamic performance of a 200MW,±100kV VSC-HVDC transmission system under some faulted conditionsusing MATLAB/Simulink. Simulation results confirm the satisfactoryperformance of the proposed system under active and reactive powervariations and fault conditions.

  19. Computed tomographic images using tube source of x rays: interior properties of the material

    Science.gov (United States)

    Rao, Donepudi V.; Takeda, Tohoru; Itai, Yuji; Seltzer, S. M.; Hubbell, John H.; Zeniya, Tsutomu; Akatsuka, Takao; Cesareo, Roberto; Brunetti, Antonio; Gigante, Giovanni E.

    2002-01-01

    An image intensifier based computed tomography scanner and a tube source of x-rays are used to obtain the images of small objects, plastics, wood and soft materials in order to know the interior properties of the material. A new method is developed to estimate the degree of monochromacy, total solid angle, efficiency and geometrical effects of the measuring system and the way to produce monoenergetic radiation. The flux emitted by the x-ray tube is filtered using the appropriate filters at the chosen optimum energy and reasonable monochromacy is achieved and the images are acceptably distinct. Much attention has been focused on the imaging of small objects of weakly attenuating materials at optimum value. At optimum value it is possible to calculate the three-dimensional representation of inner and outer surfaces of the object. The image contrast between soft materials could be significantly enhanced by optimal selection of the energy of the x-rays by Monte Carlo methods. The imaging system is compact, reasonably economic, has a good contrast resolution, simple operation and routine availability and explores the use of optimizing tomography for various applications.

  20. Batteryless wireless transmission system for electronic drum uses piezoelectric generator for play signal and power source

    International Nuclear Information System (INIS)

    Nishikawa, H; Yoshimi, A; Takemura, K; Tanaka, A; Douseki, T

    2015-01-01

    A batteryless self-powered wireless transmission system has been developed that sends a signal from a drum pad to a synthesizer. The power generated by a piezoelectric generator functions both as the “Play” signal for the synthesizer and as the power source for the transmitter. An FM transmitter, which theoretically operates with zero latency, and a receiver with quick-response squelch of the received signal were developed for wireless transmission with a minimum system delay. Experimental results for an electronic drum without any connecting wires fully demonstrated the feasibility of self-powered wireless transmission with a latency of 900 μs. (paper)

  1. Event-based motion correction for PET transmission measurements with a rotating point source

    International Nuclear Information System (INIS)

    Zhou, Victor W; Kyme, Andre Z; Meikle, Steven R; Fulton, Roger

    2011-01-01

    Accurate attenuation correction is important for quantitative positron emission tomography (PET) studies. When performing transmission measurements using an external rotating radioactive source, object motion during the transmission scan can distort the attenuation correction factors computed as the ratio of the blank to transmission counts, and cause errors and artefacts in reconstructed PET images. In this paper we report a compensation method for rigid body motion during PET transmission measurements, in which list mode transmission data are motion corrected event-by-event, based on known motion, to ensure that all events which traverse the same path through the object are recorded on a common line of response (LOR). As a result, the motion-corrected transmission LOR may record a combination of events originally detected on different LORs. To ensure that the corresponding blank LOR records events from the same combination of contributing LORs, the list mode blank data are spatially transformed event-by-event based on the same motion information. The number of counts recorded on the resulting blank LOR is then equivalent to the number of counts that would have been recorded on the corresponding motion-corrected transmission LOR in the absence of any attenuating object. The proposed method has been verified in phantom studies with both stepwise movements and continuous motion. We found that attenuation maps derived from motion-corrected transmission and blank data agree well with those of the stationary phantom and are significantly better than uncorrected attenuation data.

  2. Optimization of Coding of AR Sources for Transmission Across Channels with Loss

    DEFF Research Database (Denmark)

    Arildsen, Thomas

    Source coding concerns the representation of information in a source signal using as few bits as possible. In the case of lossy source coding, it is the encoding of a source signal using the fewest possible bits at a given distortion or, at the lowest possible distortion given a specified bit rate....... Channel coding is usually applied in combination with source coding to ensure reliable transmission of the (source coded) information at the maximal rate across a channel given the properties of this channel. In this thesis, we consider the coding of auto-regressive (AR) sources which are sources that can...... compared to the case where the encoder is unaware of channel loss. We finally provide an extensive overview of cross-layer communication issues which are important to consider due to the fact that the proposed algorithm interacts with the source coding and exploits channel-related information typically...

  3. Spallation Neutron Source Drift Tube Linac Resonance Control Cooling System Modeling

    CERN Document Server

    Tang, Johnny Y; Champion, Marianne M; Feschenko, Alexander; Gibson, Paul; Kiselev, Yuri; Kovalishin, A S; Kravchuk, Leonid V; Kvasha, Adolf; Schubert, James P

    2005-01-01

    The Resonance Control Cooling System (RCCS) for the warm linac of the Spallation Neutron Source was designed by Los Alamos National Laboratory. The primary design focus was on water cooling of individual component contributions. The sizing the RCCS water skid was accomplished by means of a specially created SINDA/FLUINT model tailored to these system requirements. A new model was developed in Matlab Simulink and incorporates actual operational values and control valve interactions. Included is the dependence of RF input power on system operation, cavity detuning values during transients, time delays that result from water flows through the heat exchanger, the dynamic process of water warm-up in the cooling system due to dissipated RF power on the cavity surface, differing contributions on the cavity detuning due to drift tube and wall heating, and a dynamic model of the heat exchanger with characteristics in close agreement to the real unit. Because of the Matlab Simulink model, investigation of a wide range ...

  4. Growth and Identification of Bacteria in N-Halamine Dental Unit Waterline Tubing Using an Ultrapure Water Source

    Science.gov (United States)

    Porteous, Nuala; Luo, Jie; Hererra, Monica; Schoolfield, John; Sun, Yuyu

    2011-01-01

    This study examined bacterial growth and type on biofilm-controlling dental unit waterline (DUWL) tubing (T) and control manufacturer's tubing (C) in a laboratory DUWL model using ultrapure source water that was cycled through the lines. Sections of tubing lines were detached and examined for biofilm growth using SEM imaging at six sampling periods. Bacteria from inside surfaces of T and C, source unit, and reservoir were cultured and enumerated. At six months, organisms were molecularly identified from the alignment matches obtained from the top three BLAST searches for the 16S region. There was a 1–3 log increase in organism growth in a clean, nonsterile reservoir within an hour. Biofilm was established on the inside surfaces of C within three weeks, but not on T. Proteobacteria, and Sphingomonas spp. were identified in the source reservoir and C line, and a variation of the genera was found in T line. PMID:22220171

  5. YouTube Videos as a Source of Information About Clinical Trials: Observational Study.

    Science.gov (United States)

    Hillyer, Grace Clarke; MacLean, Sarah A; Beauchemin, Melissa; Basch, Corey H; Schmitt, Karen M; Segall, Leslie; Kelsen, Moshe; Brogan, Frances L; Schwartz, Gary K

    2018-06-26

    Clinical trials are essential to the advancement of cancer treatment but fewer than 5% of adult cancer patients enroll in a trial. A commonly cited barrier to participation is the lack of understanding about clinical trials. Since the internet is a popular source of health-related information and YouTube is the second most visited website in the world, we examined the content of the top 115 YouTube videos about clinical trials to evaluate clinical trial information available through this medium. YouTube videos posted prior to March 2017 were searched using selected keywords. A snowballing technique was used to identify videos wherein sequential screening of the autofill search results for each set of keywords was conducted. Video characteristics (eg, number of views and video length) were recorded. The content was broadly grouped as related to purpose, phases, design, safety and ethics, and participant considerations. Stepwise multivariable logistic regression analysis was conducted to assess associations between video type (cancer vs noncancer) and video characteristics and content. In total, 115 videos were reviewed. Of these, 46/115 (40.0%) were cancer clinical trials videos and 69/115 (60.0%) were noncancer/general clinical trial videos. Most videos were created by health care organizations/cancer centers (34/115, 29.6%), were oriented toward patients (67/115, 58.3%) and the general public (68/115, 59.1%), and were informational (79/115, 68.7%); altruism was a common theme (31/115, 27.0%). Compared with noncancer videos, cancer clinical trials videos more frequently used an affective communication style and mentioned the benefits of participation. Cancer clinical trial videos were also much more likely to raise the issue of costs associated with participation (odds ratio [OR] 5.93, 95% CI 1.15-29.46) and advise patients to communicate with their physician about cancer clinical trials (OR 4.94, 95% CI 1.39-17.56). Collectively, YouTube clinical trial videos

  6. Traveling-Wave Tube Amplifier Second Harmonic as Millimeter-Wave Beacon Source for Atmospheric Propagation Studies

    Science.gov (United States)

    Simons, Rainee N.; Wintucky, Edwin G.

    2014-01-01

    This paper presents the design and test results of a CW millimeter-wave satellite beacon source, based on the second harmonic from a traveling-wave tube amplifier and utilizes a novel waveguide multimode directional coupler. A potential application of the beacon source is for investigating the atmospheric effects on Q-band (37-42 GHz) and V/W-band (71- 76 GHz) satellite-to-ground signals.

  7. Modal parameter identification based on combining transmissibility functions and blind source separation techniques

    Science.gov (United States)

    Araújo, Iván Gómez; Sánchez, Jesús Antonio García; Andersen, Palle

    2018-05-01

    Transmissibility-based operational modal analysis is a recent and alternative approach used to identify the modal parameters of structures under operational conditions. This approach is advantageous compared with traditional operational modal analysis because it does not make any assumptions about the excitation spectrum (i.e., white noise with a flat spectrum). However, common methodologies do not include a procedure to extract closely spaced modes with low signal-to-noise ratios. This issue is relevant when considering that engineering structures generally have closely spaced modes and that their measured responses present high levels of noise. Therefore, to overcome these problems, a new combined method for modal parameter identification is proposed in this work. The proposed method combines blind source separation (BSS) techniques and transmissibility-based methods. Here, BSS techniques were used to recover source signals, and transmissibility-based methods were applied to estimate modal information from the recovered source signals. To achieve this combination, a new method to define a transmissibility function was proposed. The suggested transmissibility function is based on the relationship between the power spectral density (PSD) of mixed signals and the PSD of signals from a single source. The numerical responses of a truss structure with high levels of added noise and very closely spaced modes were processed using the proposed combined method to evaluate its ability to identify modal parameters in these conditions. Colored and white noise excitations were used for the numerical example. The proposed combined method was also used to evaluate the modal parameters of an experimental test on a structure containing closely spaced modes. The results showed that the proposed combined method is capable of identifying very closely spaced modes in the presence of noise and, thus, may be potentially applied to improve the identification of damping ratios.

  8. Preliminary fracture analysis of the core pressure boundary tube for the Advanced Neutron Source Research Reactor

    International Nuclear Information System (INIS)

    Schulz, K.C.

    1995-08-01

    The outer core pressure boundary tube (CPBT) of the Advanced neutron Source (ANS) reactor being designed at Oak Ridge National Laboratory is currently specified as being composed of 6061-T6 aluminum. ASME Boiler and Pressure Vessel Code fracture analysis rules for nuclear components are based on the use of ferritic steels; the expressions, tables, charts and equations were all developed from tests and analyses conducted for ferritic steels. Because of the nature of the Code, design with thin aluminum requires analytical approaches that do not directly follow the Code. The intent of this report is to present a methodology comparable to the ASME Code for ensuring the prevention of nonductile fracture of the CPBT in the ANS reactor. 6061-T6 aluminum is known to be a relatively brittle material; the linear elastic fracture mechanics (LEFM) approach is utilized to determine allowable flaw sizes for the CPBT. A J-analysis following the procedure developed by the Electric Power Research Institute was conducted as a check; the results matched those for the LEFM analysis for the cases analyzed. Since 6061-T6 is known to embrittle when irradiated, the reduction in K Q due to irradiation is considered in the analysis. In anticipation of probable requirements regarding maximum allowable flaw size, a survey of nondestructive inspection capabilities is also presented. A discussion of probabilistic fracture mechanics approaches, principally Monte Carlo techniques, is included in this report as an introduction to what quantifying the probability of nonductile failure of the CPBT may entail

  9. Air source heat pump water heater: Dynamic modeling, optimal energy management and mini-tubes condensers

    International Nuclear Information System (INIS)

    Ibrahim, Oussama; Fardoun, Farouk; Younes, Rafic; Louahlia-Gualous, Hasna

    2014-01-01

    This paper presents a dynamic simulation model to predict the performance of an ASHPWH (air source heat pump water heater). The developed model is used to assess its performance in the Lebanese context. It is shown that for the four Lebanese climatic zones, the expected monthly values of the average COP (coefficient of performance) varies from 2.9 to 5, leading to high efficiencies compared with conventional electric water heaters. The energy savings and GHG (greenhouse gas) emissions reduction are investigated for each zone. Furthermore, it is recommended to use the ASHPWH during the period of highest daily ambient temperatures (noon or afternoon), assuming that the electricity tariff and hot water loads are constant. In addition, an optimal management model for the ASHPWH is developed and applied for a typical winter day of Beirut. Moreover, the developed dynamic model of ASHPWH is used to compare the performance of three similar systems that differ only with the condenser geometry, where results show that using mini-condenser geometries increase the COP (coefficient of performance) and consequently, more energy is saved as well as more GHG emissions are reduced. In addition, the condenser “surface compactness” is increased giving rise to an efficient compact heat exchanger. - Highlights: • Numerical modeling and experimental validation for ASHPWH (air source heat pump water heater). • Optimization of the ASHPWH-condenser length. • Comparison of the ASHPWH with conventional electric water heater according to energy efficiency and green gas house emissions. • Development of an energetic-economic optimal management model for ASHPWH. • Energetic and environmental assessment of ASHPWH with mini-tubes condensers

  10. Non-Linear Transmission Line (NLTL) Microwave Source Lecture Notes the United States Particle Accelerator School

    Energy Technology Data Exchange (ETDEWEB)

    Russell, Steven J. [Los Alamos National Laboratory; Carlsten, Bruce E. [Los Alamos National Laboratory

    2012-06-26

    We will quickly go through the history of the non-linear transmission lines (NLTLs). We will describe how they work, how they are modeled and how they are designed. Note that the field of high power, NLTL microwave sources is still under development, so this is just a snap shot of their current state. Topics discussed are: (1) Introduction to solitons and the KdV equation; (2) The lumped element non-linear transmission line; (3) Solution of the KdV equation; (4) Non-linear transmission lines at microwave frequencies; (5) Numerical methods for NLTL analysis; (6) Unipolar versus bipolar input; (7) High power NLTL pioneers; (8) Resistive versus reactive load; (9) Non-lineaer dielectrics; and (10) Effect of losses.

  11. Effect of particle size, filler loadings and x-ray tube voltage on the transmitted x-ray transmission in tungsten oxide—epoxy composites

    International Nuclear Information System (INIS)

    Noor Azman, N.Z.; Siddiqui, S.A.; Hart, R.; Low, I.M.

    2013-01-01

    The effect of particle size, filler loadings and x-ray tube voltage on the x-ray transmission in WO 3 -epoxy composites has been investigated using the mammography unit and a general radiography unit. Results indicate that nano-sized WO 3 has a better ability to attenuate the x-ray beam generated by lower tube voltages (25–35 kV) when compared to micro-sized WO 3 of the same filler loading. However, the effect of particle size on x-ray transmission was negligible at the higher x-ray tube voltages (40–120 kV). - Highlights: ► Investigated the effect of particle size of WO 3 on the x-ray attenuation ability. ► Nano-sized WO 3 has a better ability to attenuate lower x-ray energies (22–49 kV p ). ► Particle size has negligible effect at the higher x-ray energy range (40–120 kV p ).

  12. Thickness measurement for the different metals by using Cs-137 gamma source with gamma transmission technique

    International Nuclear Information System (INIS)

    Bueyuek, B.; Tugrul, B.

    2009-01-01

    The purpose of this study is an experimental analysis of thickness measurement for various metals with the gamma transmission technique using Cs-137 as the radioisotope source. Lead, steel, brass, and aluminum, which are frequently used metals in industry, were chosen for the experiments. As the radioisotope source Cs-137 was preferred for the study since it has long half-life, it is mono energetic, and it penetrates the metals that were studied. Experiments were observed in the constant experimental geometry. Calibration curves for the four metal samples were plotted using the obtained results. To test the plotted calibration curves, counts for determining thickness measurement were collected for each sample and the obtained relative count values were used in conjunction with the plotted calibration curves for each sample to determine its thickness. The thicknesses of the samples have been measured with a micrometer and the results were comparatively analyzed with the measurement results obtained by the gamma transmission technique. The results of the analyses revealed that the thickness measurement values obtained with the gamma transmission technique and the thickness measurement values obtained with the conventional technique significantly converge to each other and the difference between the two values is at an acceptable level. Therefore the reliability of thickness measurements with the gamma transmission technique and the resulting calibration curves have been demonstrated.

  13. Source identification of individual soot agglomerates in Arctic air by transmission electron microscopy

    Science.gov (United States)

    Weinbruch, S.; Benker, N.; Kandler, K.; Schütze, K.; Kling, K.; Berlinger, B.; Thomassen, Y.; Drotikova, T.; Kallenborn, R.

    2018-01-01

    Individual soot agglomerates collected at four different locations on the Arctic archipelago Svalbard (Norway) were characterised by transmission electron microscopy and energy-dispersive X-ray microanalysis. For source identification of the ambient soot agglomerates, samples from different local sources (coal burning power plants in Longyearbyen and Barentsburg, diesel and oil burning for power generation in Sveagruva and Ny Ålesund, cruise ship) as well as from other sources which may contribute to Arctic soot concentrations (biomass burning, aircraft emissions, diesel engines) were investigated. Diameter and graphene sheet separation distance of soot primary particles were found to be highly variable within each source and are not suited for source identification. In contrast, concentrations of the minor elements Si, P, K, Ca and Fe showed significant differences which can be used for source attribution. The presence/absence of externally mixed particle groups (fly ashes, tar balls, mercury particles) gives additional hints about the soot sources. Biomass/wood burning, ship emissions and coal burning in Barentsburg can be excluded as major source for ambient soot at Svalbard. The coal power plant in Longyearbyen is most likely a major source of soot in the settlement of Longyearbyen but does not contribute significantly to soot collected at the Global Atmosphere Watch station Zeppelin Mountain near Ny Ålesund. The most probable soot sources at Svalbard are aircraft emissions and diesel exhaust as well as long range transport of coal burning emissions.

  14. Propagation of Torsional Alfvén Waves from the Photosphere to the Corona: Reflection, Transmission, and Heating in Expanding Flux Tubes

    Energy Technology Data Exchange (ETDEWEB)

    Soler, Roberto; Terradas, Jaume; Oliver, Ramón; Ballester, José Luis, E-mail: roberto.soler@uib.es [Departament de Física, Universitat de les Illes Balears, E-07122 Palma de Mallorca (Spain)

    2017-05-01

    It has been proposed that Alfvén waves play an important role in the energy propagation through the solar atmospheric plasma and its heating. Here we theoretically investigate the propagation of torsional Alfvén waves in magnetic flux tubes expanding from the photosphere up to the low corona and explore the reflection, transmission, and dissipation of wave energy. We use a realistic variation of the plasma properties and the magnetic field strength with height. Dissipation by ion–neutral collisions in the chromosphere is included using a multifluid partially ionized plasma model. Considering the stationary state, we assume that the waves are driven below the photosphere and propagate to the corona, while they are partially reflected and damped in the chromosphere and transition region. The results reveal the existence of three different propagation regimes depending on the wave frequency: low frequencies are reflected back to the photosphere, intermediate frequencies are transmitted to the corona, and high frequencies are completely damped in the chromosphere. The frequency of maximum transmissivity depends on the magnetic field expansion rate and the atmospheric model, but is typically in the range of 0.04–0.3 Hz. Magnetic field expansion favors the transmission of waves to the corona and lowers the reflectivity of the chromosphere and transition region compared to the case with a straight field. As a consequence, the chromospheric heating due to ion–neutral dissipation systematically decreases when the expansion rate of the magnetic flux tube increases.

  15. Acrylamide graft over silicone rubber tubes by simultaneous irradiation in 60 Co source

    International Nuclear Information System (INIS)

    Julio, C.A.; Higa, O.Z.

    1992-01-01

    The synthesis of a hydrogel having silicone rubber tubes as support was carried out through the radiation grafting technique. The best conditions for the grafting development were determined in relation to the monomer and inhibitor concentration, dose rate and irradiation dose. The addition of cupric ions in the process inhibited the acrylamide homo polymerization and enhanced the grafting yield. The water content in the grafted tubes characterized the hydrophilic property of the material. (author)

  16. YouTube as a source of chronic obstructive pulmonary disease patient education: a social media content analysis.

    Science.gov (United States)

    Stellefson, Michael; Chaney, Beth; Ochipa, Kathleen; Chaney, Don; Haider, Zeerak; Hanik, Bruce; Chavarria, Enmanuel; Bernhardt, Jay M

    2014-05-01

    The aim of the present study is to conduct a social media content analysis of chronic obstructive pulmonary disease (COPD) patient education videos on YouTube. A systematic search protocol was used to locate 223 videos. Two independent coders evaluated each video to determine topics covered, media source(s) of posted videos, information quality as measured by HONcode guidelines for posting trustworthy health information on the Internet, and viewer exposure/engagement metrics. Over half the videos (n = 113, 50.7%) included information on medication management, with far fewer videos on smoking cessation (n = 40, 17.9%). Most videos were posted by a health agency or organization (n = 128, 57.4%), and the majority of videos were rated as high quality (n = 154, 69.1%). HONcode adherence differed by media source (Fisher's exact test = 20.52, p = 0.01), however with user-generated content receiving the lowest quality scores. Overall level of user engagement as measured by number of "likes," "favorites," "dislikes," and user comments was low (median range = 0-3, interquartile range = 0-16) across all sources of media. Study findings suggest that COPD education via YouTube has the potential to reach and inform patients; however, existing video content and quality varies significantly. Future interventions should help direct individuals with COPD to engage with high-quality patient education videos on YouTube that are posted by reputable health organizations and qualified medical professionals. Patients should be educated to avoid and/or critically view low-quality videos posted by individual YouTube users who are not health professionals.

  17. Potential Sources and Transmission of Salmonella and Antimicrobial Resistance in Kampala, Uganda.

    Directory of Open Access Journals (Sweden)

    Josephine A Afema

    Full Text Available In sub‒Saharan Africa, non‒typhoidal Salmonellae (NTS cause invasive disease particularly in children and HIV infected adults, but the disease epidemiology is poorly understood. Between 2012 and 2013, we investigated NTS sources and transmission in Kampala. We detected Salmonella in 60% of the influent and 60% of the effluent samples from a wastewater treatment plant and 53.3% of the influent and 10% of the effluent samples from waste stabilization ponds that serve the human population; 40.9% of flush‒water samples from ruminant slaughterhouses, 6.6% of the poultry fecal samples from live bird markets and 4% of the fecal samples from swine at slaughter; and in 54.2% of the water samples from a channel that drains storm-water and effluents from the city. We obtained 775 Salmonella isolates, identified 32 serovars, and determined resistance to 15 antimicrobials. We genotyped common serovars using multiple‒locus variable number tandem repeats analysis or pulsed‒field gel electrophoresis. In addition, we analyzed 49 archived NTS isolates from asymptomatic livestock and human clinical cases. Salmonella from ruminant and swine sources were mostly pan‒susceptible (95% while poultry isolates were generally more resistant. Salmonella Kentucky isolated from poultry exhibited extensive drug resistance characterized by resistance to 10 antimicrobials. Interestingly, similar genotypes of S. Kentucky but with less antimicrobial resistance (AMR were found in poultry, human and environmental sources. The observed AMR patterns could be attributed to host or management factors associated with production. Alternatively, S. Kentucky may be prone to acquiring AMR. The factors driving AMR remain poorly understood and should be elucidated. Overall, shared genotypes and AMR phenotypes were found in NTS from human, livestock and environmental sources, suggesting zoonotic and environmental transmissions most likely occur. Information from this study could be

  18. Comparison of cluster-based and source-attribution methods for estimating transmission risk using large HIV sequence databases.

    Science.gov (United States)

    Le Vu, Stéphane; Ratmann, Oliver; Delpech, Valerie; Brown, Alison E; Gill, O Noel; Tostevin, Anna; Fraser, Christophe; Volz, Erik M

    2018-06-01

    Phylogenetic clustering of HIV sequences from a random sample of patients can reveal epidemiological transmission patterns, but interpretation is hampered by limited theoretical support and statistical properties of clustering analysis remain poorly understood. Alternatively, source attribution methods allow fitting of HIV transmission models and thereby quantify aspects of disease transmission. A simulation study was conducted to assess error rates of clustering methods for detecting transmission risk factors. We modeled HIV epidemics among men having sex with men and generated phylogenies comparable to those that can be obtained from HIV surveillance data in the UK. Clustering and source attribution approaches were applied to evaluate their ability to identify patient attributes as transmission risk factors. We find that commonly used methods show a misleading association between cluster size or odds of clustering and covariates that are correlated with time since infection, regardless of their influence on transmission. Clustering methods usually have higher error rates and lower sensitivity than source attribution method for identifying transmission risk factors. But neither methods provide robust estimates of transmission risk ratios. Source attribution method can alleviate drawbacks from phylogenetic clustering but formal population genetic modeling may be required to estimate quantitative transmission risk factors. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  19. YouTube as a source of information on rhinosinusitis: the good, the bad and the ugly.

    Science.gov (United States)

    Biggs, T C; Bird, J H; Harries, P G; Salib, R J

    2013-08-01

    YouTube is an internet-based repository of user-generated content. This study aimed to determine whether YouTube represented a valid and reliable patient information resource for the lay person on the topic of rhinosinusitis. The study included the first 100 YouTube videos found using the search term 'sinusitis'. Videos were graded on their ability to inform the lay person on the subject of rhinosinusitis. Forty-five per cent of the videos were deemed to provide some useful information. Fifty-five per cent of the videos contained little or no useful facts, 27 per cent of which contained potentially misleading or even dangerous information. Videos uploaded by medical professionals or those from health information websites contained more useful information than those uploaded by independent users. YouTube appears to be an unreliable resource for accurate and up to date medical information relating to rhinosinusitis. However, it may provide some useful information if mechanisms existed to direct lay people to verifiable and credible sources.

  20. Phase-contrast imaging and tomography at 60 keV using a conventional x-ray tube source

    International Nuclear Information System (INIS)

    Donath, Tilman; Bunk, Oliver; Groot, Waldemar; Bednarzik, Martin; Gruenzweig, Christian; David, Christian; Pfeiffer, Franz; Hempel, Eckhard; Popescu, Stefan; Hoheisel, Martin

    2009-01-01

    Phase-contrast imaging at laboratory-based x-ray sources using grating interferometers has been developed over the last few years for x-ray energies of up to 28 keV. Here, we show first phase-contrast projection and tomographic images recorded at significantly higher x-ray energies, produced by an x-ray tube source operated at 100 kV acceleration voltage. We find our measured tomographic phase images in good agreement with tabulated data. The extension of phase-contrast imaging to this significantly higher x-ray energy opens up many applications of the technique in medicine and industrial nondestructive testing.

  1. Soil temperature distribution around a U-tube heat exchanger in a multi-function ground source heat pump system

    International Nuclear Information System (INIS)

    Li Shuhong; Yang Weihua; Zhang Xiaosong

    2009-01-01

    The imbalance of heat extracted from the earth by the underground heat exchangers in winter and ejected into it in summer is expected to affect the long term performance of conventional ground source heat pump (GSHP) in territories with a cold winter and a warm summer such as the middle and downstream areas of the Yangtze River in China. This paper presents a new multi-function ground source heat pump (MFGSHP) system which supplies hot water as well as space cooling/heating to mitigate the soil imbalance of the extracted and ejected heat by a ground source heat pump system. The heat transfer characteristic is studied and the soil temperature around the underground heat exchangers are simulated under a typical climatic condition of the Yangtze River. A three-dimensional model was constructed with the commercial computational fluid dynamics software FLUENT based on the inner heat source theory. Temperature distribution and variation trend of a tube cluster of the underground heat exchanger are simulated for the long term performance. The results show that the soil temperature around the underground tube keeps increasing due to the surplus heat ejected into the earth in summer, which deteriorates the system performance and may lead to the eventual system deterioration. The simulation shows that MFGSHP can effectively alleviate the temperature rise by balancing the heat ejected to/extracted from underground by the conventional ground source heat pump system. The new system also improves the energy efficiency.

  2. Electron Source Brightness and Illumination Semi-Angle Distribution Measurement in a Transmission Electron Microscope.

    Science.gov (United States)

    Börrnert, Felix; Renner, Julian; Kaiser, Ute

    2018-05-21

    The electron source brightness is an important parameter in an electron microscope. Reliable and easy brightness measurement routes are not easily found. A determination method for the illumination semi-angle distribution in transmission electron microscopy is even less well documented. Herein, we report a simple measurement route for both entities and demonstrate it on a state-of-the-art instrument. The reduced axial brightness of the FEI X-FEG with a monochromator was determined to be larger than 108 A/(m2 sr V).

  3. Thermal performance and pressure drop of spiral-tube ground heat exchangers for ground-source heat pump

    International Nuclear Information System (INIS)

    Jalaluddin; Miyara, Akio

    2015-01-01

    Thermal performance and pressure drop of the spiral-tube GHE were evaluated in this present work. A numerical simulation tool was used to carry out this research. The heat exchange rates per meter borehole depth of the spiral-tube GHE with various pitches and their pressure drops were compared with that of the U-tube GHE. Furthermore, a comparative analysis between a spiral pipe and straight pipe was performed. In comparison with the straight pipe, using the spiral pipe in the borehole increased the heat exchange rate to the ground per meter borehole depth. However, the pressure drop of water flow also increased due to increasing the length of pipe per meter borehole depth and its spiral geometry. The accuracy of the numerical model was verified for its pressure drop with some pressure drop correlations. The heat exchange rate and pressure drop of the GHEs are presented. As an example, the heat exchange rate per meter borehole depth of spiral pipe with 0.05 m pitch in the turbulent flow increased of 1.5 times. Its pressure drop also increased of 6 times. However, from the view point of energy efficiency, using the spiral pipe in the ground-source heat pump system gives a better performance than using the straight pipe. The heat exchange rate and pressure drop are important parameter in design of the ground-source heat pump (GSHP) system. - Highlights: • Thermal performance and pressure drop of spiral-tube GHE are presented. • Effects of spiral pitch on thermal performance and pressure drop are analyzed. • Using a spiral pipe increases heat exchange rate per meter borehole depth of GHE. • Pressure drop per meter borehole depth also increases in the spiral pipe.

  4. Photonic crystal fibers used in a multi-wavelength source and as transmission fiber in a WDM system

    DEFF Research Database (Denmark)

    Andersen, Peter Andreas; Zsigri, Beata; Peucheret, Christophe

    2004-01-01

    We present a WDM system based entirely on photonic crystal fibers. It includes a novel dispersion flattened highly nonlinear PCF to generate supercontinuum used in a multiwavelength pulse source and a 5.6 km transmission PCF.......We present a WDM system based entirely on photonic crystal fibers. It includes a novel dispersion flattened highly nonlinear PCF to generate supercontinuum used in a multiwavelength pulse source and a 5.6 km transmission PCF....

  5. Assessment of grid optimisation measures for the German transmission grid using open source grid data

    Science.gov (United States)

    Böing, F.; Murmann, A.; Pellinger, C.; Bruckmeier, A.; Kern, T.; Mongin, T.

    2018-02-01

    The expansion of capacities in the German transmission grid is a necessity for further integration of renewable energy sources into the electricity sector. In this paper, the grid optimisation measures ‘Overhead Line Monitoring’, ‘Power-to-Heat’ and ‘Demand Response in the Industry’ are evaluated and compared against conventional grid expansion for the year 2030. Initially, the methodical approach of the simulation model is presented and detailed descriptions of the grid model and the used grid data, which partly originates from open-source platforms, are provided. Further, this paper explains how ‘Curtailment’ and ‘Redispatch’ can be reduced by implementing grid optimisation measures and how the depreciation of economic costs can be determined considering construction costs. The developed simulations show that the conventional grid expansion is more efficient and implies more grid relieving effects than the evaluated grid optimisation measures.

  6. Natural plant sugar sources of Anopheles mosquitoes strongly impact malaria transmission potential.

    Directory of Open Access Journals (Sweden)

    Weidong Gu

    Full Text Available An improved knowledge of mosquito life history could strengthen malaria vector control efforts that primarily focus on killing mosquitoes indoors using insecticide treated nets and indoor residual spraying. Natural sugar sources, usually floral nectars of plants, are a primary energy resource for adult mosquitoes but their role in regulating the dynamics of mosquito populations is unclear. To determine how the sugar availability impacts Anopheles sergentii populations, mark-release-recapture studies were conducted in two oases in Israel with either absence or presence of the local primary sugar source, flowering Acacia raddiana trees. Compared with population estimates from the sugar-rich oasis, An. sergentii in the sugar-poor oasis showed smaller population size (37,494 vs. 85,595, lower survival rates (0.72 vs. 0.93, and prolonged gonotrophic cycles (3.33 vs. 2.36 days. The estimated number of females older than the extrinsic incubation period of malaria (10 days in the sugar rich site was 4 times greater than in the sugar poor site. Sugar feeding detected in mosquito guts in the sugar-rich site was significantly higher (73% than in the sugar-poor site (48%. In contrast, plant tissue feeding (poor quality sugar source in the sugar-rich habitat was much less (0.3% than in the sugar-poor site (30%. More important, the estimated vectorial capacity, a standard measure of malaria transmission potential, was more than 250-fold higher in the sugar-rich oasis than that in the sugar-poor site. Our results convincingly show that the availability of sugar sources in the local environment is a major determinant regulating the dynamics of mosquito populations and their vector potential, suggesting that control interventions targeting sugar-feeding mosquitoes pose a promising tactic for combating transmission of malaria parasites and other pathogens.

  7. YouTube as a source of quit smoking information for people living with mental illness.

    Science.gov (United States)

    Sharma, Ratika; Lucas, Maya; Ford, Pauline; Meurk, Carla; Gartner, Coral E

    2016-11-01

    YouTube is the most popular video sharing website, and is increasingly used to broadcast health information including smoking cessation advice. This study examines the quality and quantity of YouTube quit smoking videos targeted at people living with mental illness (MI). We systematically searched YouTube using selected relevant search terms. The first 50 videos obtained for each search term were screened for relevance and further videos screened through snowball sampling. Forty unique, English language videos focussing on people with MI were included in the assessment and evaluated for general video characteristics, themes, format, targeted smoking cessation and harm reduction information. Most videos either discussed the problem of high smoking rates among people with MI (n=12) or smoking cessation programmes and policies at an institutional level (n=13). Only nine videos were aimed at providing quit smoking advice to this population. One video recommended higher doses of nicotine replacement therapy (NRT) for people with MI while six videos referred to possible changes in medication dosage on quitting smoking. Four videos suggested cutting down smoking for harm reduction. Very few YouTube videos specifically focus on the problem of high smoking rates among people with MI and even fewer provide targeted smoking cessation and harm reduction advice for this priority population. There is a need to develop comprehensive, evidence based, quit smoking video resources for smokers with a MI. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  8. Molecular Approaches to Understanding Transmission and Source Attribution in Nontyphoidal Salmonella and Their Application in Africa.

    Science.gov (United States)

    Mather, Alison E; Vaughan, Timothy G; French, Nigel P

    2015-11-01

    Nontyphoidal Salmonella (NTS) is a frequent cause of diarrhea around the world, yet in many African countries it is more commonly associated with invasive bacterial disease. Various source attribution models have been developed that utilize microbial subtyping data to assign cases of human NTS infection to different animal populations and foods of animal origin. Advances in molecular microbial subtyping approaches, in particular whole-genome sequencing, provide higher resolution data with which to investigate these sources. In this review, we provide updates on the source attribution models developed for Salmonella, and examine the application of whole-genome sequencing data combined with evolutionary modeling to investigate the putative sources and transmission pathways of NTS, with a focus on the epidemiology of NTS in Africa. This is essential information to decide where, what, and how control strategies might be applied most effectively. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  9. Psoriasis and the Digital Landscape: YouTube as an Information Source for Patients and Medical Professionals.

    Science.gov (United States)

    Lenczowski, Emily; Dahiya, Madhu

    2018-03-01

    Background: YouTube is the second most commonly accessed website worldwide, but little is known about the accuracy of its medical content. We performed a review to analyze the type and quality of content in a YouTube search with respect to the treatment of psoriasis. Methods: The first 10 result pages of YouTube were searched using the term psoriasis treatment with applied filters. One-hundred and eighty-two videos were reviewed and characterized by the source of content. Results: Of the identified videos, 7.1 percent had medical institutions or verified physicians as authors; 12.1 percent had a media-affiliated author; 1.6 percent were posted by a pharmaceutical company; 11.5 percent contained "miracle-type" product advertisements with included links to product purchase websites; and 69.2 percent were holistic in nature, describing "natural" supplements and diets necessary for adequate psoriasis treatment and cure. Conclusion: This review emphasizes the need for an increase in the online presence of medical institutions to augment the dissemination of correct health information.

  10. Forced sound transmission through a finite-sized single leaf panel subject to a point source excitation.

    Science.gov (United States)

    Wang, Chong

    2018-03-01

    In the case of a point source in front of a panel, the wavefront of the incident wave is spherical. This paper discusses spherical sound waves transmitting through a finite sized panel. The forced sound transmission performance that predominates in the frequency range below the coincidence frequency is the focus. Given the point source located along the centerline of the panel, forced sound transmission coefficient is derived through introducing the sound radiation impedance for spherical incident waves. It is found that in addition to the panel mass, forced sound transmission loss also depends on the distance from the source to the panel as determined by the radiation impedance. Unlike the case of plane incident waves, sound transmission performance of a finite sized panel does not necessarily converge to that of an infinite panel, especially when the source is away from the panel. For practical applications, the normal incidence sound transmission loss expression of plane incident waves can be used if the distance between the source and panel d and the panel surface area S satisfy d/S>0.5. When d/S ≈0.1, the diffuse field sound transmission loss expression may be a good approximation. An empirical expression for d/S=0  is also given.

  11. [YouTube as an information source of spinal anesthesia, epidural anesthesia and combined spinal and epidural anesthesia].

    Science.gov (United States)

    Tulgar, Serkan; Selvi, Onur; Serifsoy, Talat Ercan; Senturk, Ozgur; Ozer, Zeliha

    Social media as YouTube have become a part of daily life and many studies evaluated health-related YouTube videos. Our aim was to evaluate videos available on YouTube for the conformity to textbook information and their sufficiency as a source for patient information. A search of the YouTube website was performed using the keywords "spinal anesthesia, epidural anesthesia, combined spinal epidural anesthesia". Firstly, 180 videos were evaluated and the characteristics of the video were noted, and the features of the video too were noted if the video was regarding neuraxial anesthesia. Questionnaire 1 (Q1) evaluating the video quality relating to neuraxial anesthesia was designed using a textbook as reference and questionnaire 2 (Q2) was designed for evaluating patient information. After exclusions, 40 videos were included in the study. There was no difference in Q1 or Q2 scores when videos were grouped into 4 quarters according to their appearance order, time since upload or views to length rate (p>0.05). There was no statistical difference between Q1 or Q2 scores for spinal, epidural or combined videos (p>0.05). Videos prepared by a healthcare institute have a higher score in both Questionnaires 1 and 2 (10.87±4.28 vs. 5.84±2.90, p=0.044 and 3.89±5.43 vs. 1.19±3.35, p=0.01 respectively). Videos prepared by institutes, societies, etc. were of higher educational value, but were still very lacking. Videos should be prepared in adherence to available and up-to-date guidelines taking into consideration appropriate step by step explanation of each procedure, patient safety and frequently asked questions. Copyright © 2016 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  12. New light sources on the basis of electromagnetic shock T and H tubes

    International Nuclear Information System (INIS)

    Basov, Yu. G.; Sereda, N.I.; Skvortsov, B.V.; Sysun, V.V.

    Experimental investigation of plasma light emission was carried out on electromagnetic shock tubes filled with xenon to initial pressure of 10-100 mm Hg. T - and H- discharge devices were connected to the low-inductive discharge circuit (C=12 μF, L=0.43 μH, U=10 - 30 kV). The discharge growth was observed with a high-speed photorecorder. In the course of the investigation lighting parameters of the devices were measured as a function of xenon initial pressure and discharge energy

  13. Estimating uncertainty in subsurface glider position using transmissions from fixed acoustic tomography sources.

    Science.gov (United States)

    Van Uffelen, Lora J; Nosal, Eva-Marie; Howe, Bruce M; Carter, Glenn S; Worcester, Peter F; Dzieciuch, Matthew A; Heaney, Kevin D; Campbell, Richard L; Cross, Patrick S

    2013-10-01

    Four acoustic Seagliders were deployed in the Philippine Sea November 2010 to April 2011 in the vicinity of an acoustic tomography array. The gliders recorded over 2000 broadband transmissions at ranges up to 700 km from moored acoustic sources as they transited between mooring sites. The precision of glider positioning at the time of acoustic reception is important to resolve the fundamental ambiguity between position and sound speed. The Seagliders utilized GPS at the surface and a kinematic model below for positioning. The gliders were typically underwater for about 6.4 h, diving to depths of 1000 m and traveling on average 3.6 km during a dive. Measured acoustic arrival peaks were unambiguously associated with predicted ray arrivals. Statistics of travel-time offsets between received arrivals and acoustic predictions were used to estimate range uncertainty. Range (travel time) uncertainty between the source and the glider position from the kinematic model is estimated to be 639 m (426 ms) rms. Least-squares solutions for glider position estimated from acoustically derived ranges from 5 sources differed by 914 m rms from modeled positions, with estimated uncertainty of 106 m rms in horizontal position. Error analysis included 70 ms rms of uncertainty due to oceanic sound-speed variability.

  14. A study on the accuracy of source position in HDR brachytherapy according to the curvature of universal application transfer tube and applicator type

    International Nuclear Information System (INIS)

    Shin, Hyeon Kyung; Lee, Sang Kyoo; Kim, Joo Ho; Cho, Jeong Hee

    2015-01-01

    The goal of this study was to verify and analyze the source position according to the curvature of the universal applicator and 4 different angle applicators when using RALS(Remote After Loading System). An interval of 1 cm and 15 second dwell times in each source position were applied for plan. To verify the accuracy of source position, we narrowed the distance between MultiSource container and GAFCHROMIC? EBT3 film by 5 cm, 10 cm, 20 cm so that the universal applicator transfer tube had some curvature. Also 4 applicators(Intrauterine tube: 0° , 15°, 30° , Ovoid tube: 65° ) were used in the same condition. The differences between desired and actual source position were measured by using Image J. In case of using 4 different angles of applicator with the straight universal applicator transfer tube, the average error was the lowest for 0°applicator, greatest for 65°applicator. However, All average errors were within ±2 mm recommended in TG-56. When MultiSource container was moved 5 cm, 10 cm, 20 cm towards the EBT3 film, the average errors were beyond ±2 mm. The first dwell position was relatively located in accuracy, while the second and third dwells were displaced by an increasing magnitude with increasing curvature of the transfer tube. Furthermore, with increasing the angle of applicators, the error of all other dwell positioning was increased. The results of this study showed that both the curvature of universal applicator transfer tube and the angle of applicators affect the source dwell position. It is recommended that using straight universal applicator transfer tubes is followed in all cases, in order to avoid deviations in the delivered source dwell position. Also, It is advisable to verify the actual dwell position, using video camera quality control tool prior to all treatments

  15. Characteristics of a four element gyromagnetic nonlinear transmission line array high power microwave source

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, J. M., E-mail: jared.johnson@ttu.edu; Reale, D. V.; Garcia, R. S.; Cravey, W. H.; Neuber, A. A.; Dickens, J. C.; Mankowski, J. J. [Center for Pulsed Power and Power Electronics Department of Electrical and Computer Engineering, Texas Tech University, Lubbock, Texas 79409 (United States); Krile, J. T. [Department of Electromagnetics and Sensor Systems, Naval Surface Warfare Center - Dahlgren Division, Dahlgren, Virginia 22448 (United States)

    2016-05-15

    In this paper, a solid-state four element array gyromagnetic nonlinear transmission line high power microwave system is presented as well as a detailed description of its subsystems and general output capabilities. This frequency agile S-band source is easily adjusted from 2-4 GHz by way of a DC driven biasing magnetic field and is capable of generating electric fields of 7.8 kV/m at 10 m correlating to 4.2 MW of RF power with pulse repetition frequencies up to 1 kHz. Beam steering of the array at angles of ±16.7° is also demonstrated, and the associated general radiation pattern is detailed.

  16. YouTube as a potential source of information on deep venous thrombosis.

    Science.gov (United States)

    Bademci, Mehmet Ş; Yazman, Serkan; Güneş, Tevfik; Ocakoglu, Gokhan; Tayfur, Kaptanderya; Gokalp, Orhan

    2017-09-01

    Background No work has been reported on the use of video websites to learn about deep vein thrombosis and the value of education using them. We examined the characteristics and scientific accuracy of videos related to deep vein thrombosis on YouTube. Methods YouTube was surveyed using no filter and the key words 'deep vein thrombosis' and 'leg vein clot' in June 2016. The videos evaluated were divided into three groups in terms of their scientific content, accuracy, and currency: useful, partly useful, and useless. Results Of the 1200 videos watched, 715 (59.58%) were excluded with the exclusion criteria. Although most of the videos uploaded (22.9%, n = 111) were created by physicians, the number of views for website-based videos was significantly higher (p = 0.002). When the uploaded videos were assessed in terms of their usefulness, videos from physicians and hospitals were statistically more useful than other videos (p < 0.001). Conclusions For videos created by medical professionals to be of higher quality, we believe they should be more up-to-date and comprehensive, and contain animations about treatment modalities and early diagnosis in particular.

  17. Automobile windshield washer fluid: A potential source of transmission for Legionella

    Energy Technology Data Exchange (ETDEWEB)

    Schwake, David Otto [School of Life Sciences, Arizona State University, P.O. Box 875306, Tempe, AZ 85287 (United States); Alum, Absar [School of Sustainable Engineering and the Built Environment, Arizona State University, P.O. Box 875306, Tempe, AZ 85287 (United States); Abbaszadegan, Morteza, E-mail: abbaszadegan@asu.edu [School of Sustainable Engineering and the Built Environment, Arizona State University, P.O. Box 875306, Tempe, AZ 85287 (United States)

    2015-09-01

    Epidemiological evidence suggesting driving cars to be a risk factor for legionellosis has prompted public health studies to investigate vehicle windshield washer fluid as a novel transmission source of this disease. The goal of the current study was to investigate whether or not windshield washer fluid could serve as a potential source of transmission for Legionella. A wide variation in the survival of L. pneumophila was observed when incubated in different washer fluids at 25 and 37 °C, however, one brand tested supported Legionella survival similar to or greater than sterilized deionized water. In addition, 1 L of tap water contained in a washer fluid reservoir was able to support population growth and survival of Legionella for several months. In a field study examining the windshield washer fluid of 12 elementary school buses, Legionella were detected from 84% of samples at a high concentration of 8.1 × 10{sup 4} CFU/mL. Culturable cells were also detected in aerosolized washer fluid during washer fluid spray. By demonstrating survival in certain windshield washer fluids, growth within washer fluid reservoirs, and the presence of viable cells in bus washer fluid spray, we have provided evidence suggesting the potential for a novel route of Legionella exposure. - Highlights: • L. pneumophila survival in one brand of washer fluid and sterilized deionized water were similar. • Legionella population was maintained in tap water for several months. • Culturable Legionella were detected in 10 of 12 school bus washer fluid reservoirs sampled. • Legionella concentrations up to 8.1 × 104 CFU/mL were detected in school bus washer fluid. • L. pneumophila was detected in washer fluid reservoirs and aerosolized washer fluid.

  18. Automobile windshield washer fluid: A potential source of transmission for Legionella

    International Nuclear Information System (INIS)

    Schwake, David Otto; Alum, Absar; Abbaszadegan, Morteza

    2015-01-01

    Epidemiological evidence suggesting driving cars to be a risk factor for legionellosis has prompted public health studies to investigate vehicle windshield washer fluid as a novel transmission source of this disease. The goal of the current study was to investigate whether or not windshield washer fluid could serve as a potential source of transmission for Legionella. A wide variation in the survival of L. pneumophila was observed when incubated in different washer fluids at 25 and 37 °C, however, one brand tested supported Legionella survival similar to or greater than sterilized deionized water. In addition, 1 L of tap water contained in a washer fluid reservoir was able to support population growth and survival of Legionella for several months. In a field study examining the windshield washer fluid of 12 elementary school buses, Legionella were detected from 84% of samples at a high concentration of 8.1 × 10 4 CFU/mL. Culturable cells were also detected in aerosolized washer fluid during washer fluid spray. By demonstrating survival in certain windshield washer fluids, growth within washer fluid reservoirs, and the presence of viable cells in bus washer fluid spray, we have provided evidence suggesting the potential for a novel route of Legionella exposure. - Highlights: • L. pneumophila survival in one brand of washer fluid and sterilized deionized water were similar. • Legionella population was maintained in tap water for several months. • Culturable Legionella were detected in 10 of 12 school bus washer fluid reservoirs sampled. • Legionella concentrations up to 8.1 × 104 CFU/mL were detected in school bus washer fluid. • L. pneumophila was detected in washer fluid reservoirs and aerosolized washer fluid

  19. Crowd-Sourced Amputee Gait Data: A Feasibility Study Using YouTube Videos of Unilateral Trans-Femoral Gait.

    Directory of Open Access Journals (Sweden)

    James Gardiner

    Full Text Available Collecting large datasets of amputee gait data is notoriously difficult. Additionally, collecting data on less prevalent amputations or on gait activities other than level walking and running on hard surfaces is rarely attempted. However, with the wealth of user-generated content on the Internet, the scope for collecting amputee gait data from alternative sources other than traditional gait labs is intriguing. Here we investigate the potential of YouTube videos to provide gait data on amputee walking. We use an example dataset of trans-femoral amputees level walking at self-selected speeds to collect temporal gait parameters and calculate gait asymmetry. We compare our YouTube data with typical literature values, and show that our methodology produces results that are highly comparable to data collected in a traditional manner. The similarity between the results of our novel methodology and literature values lends confidence to our technique. Nevertheless, clear challenges with the collection and interpretation of crowd-sourced gait data remain, including long term access to datasets, and a lack of validity and reliability studies in this area.

  20. Crowd-Sourced Amputee Gait Data: A Feasibility Study Using YouTube Videos of Unilateral Trans-Femoral Gait.

    Science.gov (United States)

    Gardiner, James; Gunarathne, Nuwan; Howard, David; Kenney, Laurence

    2016-01-01

    Collecting large datasets of amputee gait data is notoriously difficult. Additionally, collecting data on less prevalent amputations or on gait activities other than level walking and running on hard surfaces is rarely attempted. However, with the wealth of user-generated content on the Internet, the scope for collecting amputee gait data from alternative sources other than traditional gait labs is intriguing. Here we investigate the potential of YouTube videos to provide gait data on amputee walking. We use an example dataset of trans-femoral amputees level walking at self-selected speeds to collect temporal gait parameters and calculate gait asymmetry. We compare our YouTube data with typical literature values, and show that our methodology produces results that are highly comparable to data collected in a traditional manner. The similarity between the results of our novel methodology and literature values lends confidence to our technique. Nevertheless, clear challenges with the collection and interpretation of crowd-sourced gait data remain, including long term access to datasets, and a lack of validity and reliability studies in this area.

  1. Radiation-resistant device with tubes for the introduction of a liquid, e.g., blood into a container holding a radioactive source

    International Nuclear Information System (INIS)

    Rasmussen, I.

    1978-01-01

    The invention concerns a radiation-resistant device with tubing for the introduction/removal of a liquid (e.g. blood to and from a patient) via an at least partly curved channel into and out of a container holding a radioactive source. A break is made with the idea that it is necessary to use a circular-cylindrical tube as introduction device for the material to be irradiated. If made of materials suitable for the purpose, such tubing is safe and compressible in the longitudinal direction. The disadvantages and limitations of earlier constructions can be ascribed to this circumstance. A characteristic of the present invention is an elongated, pressure-resistant insertion ''cage'', flexible in at least one direction, used for the introduction of a minimum of one tubing into the container through the channel. The tubing enters and leaves at the same end of the insert cage. (BP)

  2. Analytic model of the stress waves propagation in thin wall tubes, seeking the location of a harmonic point source in its surface

    International Nuclear Information System (INIS)

    Boaratti, Mario Francisco Guerra

    2006-01-01

    Leaks in pressurized tubes generate acoustic waves that propagate through the walls of these tubes, which can be captured by accelerometers or by acoustic emission sensors. The knowledge of how these walls can vibrate, or in another way, how these acoustic waves propagate in this material is fundamental in the detection and localization process of the leak source. In this work an analytic model was implemented, through the motion equations of a cylindrical shell, with the objective to understand the behavior of the tube surface excited by a point source. Since the cylindrical surface has a closed pattern in the circumferential direction, waves that are beginning their trajectory will meet with another that has already completed the turn over the cylindrical shell, in the clockwise direction as well as in the counter clockwise direction, generating constructive and destructive interferences. After enough time of propagation, peaks and valleys in the shell surface are formed, which can be visualized through a graphic representation of the analytic solution created. The theoretical results were proven through measures accomplished in an experimental setup composed of a steel tube finished in sand box, simulating the condition of infinite tube. To determine the location of the point source on the surface, the process of inverse solution was adopted, that is to say, known the signals of the sensor disposed in the tube surface , it is determined through the theoretical model where the source that generated these signals can be. (author)

  3. MO-AB-BRA-08: A Modular Multi-Source X-Ray Tube for Novel Computed Tomography Applications

    Energy Technology Data Exchange (ETDEWEB)

    Walker, B; Radtke, J; Chen, G; Mackie, T [University of Wisconsin Madison, Madison, WI (United States); Petry, G; Swader, R; Eliceiri, K [Morgridge Institute for Research, Madison, WI (United States)

    2016-06-15

    Purpose: To develop and build a practical implementation of an x-ray line source for the rapidly increasing number of multi-source imaging applications in CT. Methods: An innovative x-ray tube was designed using CST Particle Studio, ANSYS, and SolidWorks. A slowly varying magnetic field is synchronized with microsecond gating of multiple thermionic electron sources. Electrostatic simulations were run to optimize the geometry of the optics and prevent electrode arcing. Magnetostatic simulations were used for beam deflection studies and solenoid design. Particle beam trajectories were explored with an emphasis on focusing, acceleration, deflection, and space charge effects. Thermal constraints were analyzed for both transient and steady-state regimes. Electromagnetic simulations informed the design of a prototype unit under construction. Results: Particle tracking simulations for a benchtop system demonstrate that three 80 keV electron beams are able to be finely controlled and laterally swept a combined distance of 15 cm over a stationary target with an oscillating magnetic field in the hundreds of gauss. The beams are pulsed according to scanning sequences developed for implementation in a mock stationary CT scanner capable of a 30 ms temporal resolution. Beam spot diameters are approximately 1 mm for 30 mA beams and the stationary target stays well within thermal limits. The relevant hardware and control circuits were developed for incorporation into a physical prototype. Conclusion: A new multi-source x-ray tube was designed in a modular form factor to push the barriers of high-speed CT and spur growth in emerging imaging applications. This technology can be used as the basis for a stationary high-speed CT scanner, a system for generating a virtual fan-beam for dose reduction, or for reducing scatter radiation in cone-beam CT utilizing a tetrahedron beam CT geometry. A 2.4 kW benchtop system is currently being built to show proof of concept for the tube. Support

  4. Campylobacter genotypes from poultry transportation crates indicate a source of contamination and transmission.

    Science.gov (United States)

    Hastings, R; Colles, F M; McCarthy, N D; Maiden, M C J; Sheppard, S K

    2011-01-01

    Crates used to transport live poultry can be contaminated with Campylobacter, despite periodic sanitization, and are potential vectors for transmission between flocks. We investigated the microbial contamination of standard and silver ion containing crates in normal use and the genetic structure of associated Campylobacter populations. Bacteria from crates were enumerated by appropriate culture techniques, and multilocus sequence typing (MLST) was used to determine the genetic structure of Campylobacters isolated from standard and silver ion containing crates. Compared to standard crates, counts of bacteria, including Campylobacter, were consistently lower on silver ion containing crates throughout the decontamination process. In total, 16 different sequence types were identified from 89 Campylobacter jejuni isolates from crates. These were attributed to putative source population (chicken, cattle, sheep, the environment, wild bird) using the population genetic model, structure. Most (89%) were attributed to chicken, with 22% attribution to live chicken and 78% to retail poultry meat. MLST revealed a progressive shift in allele frequencies through the crate decontamination process. Campylobacter on crates survived for at least 3 h after sanitization, a period of time equivalent to the journey from the processing plant to the majority of farms in the catchment, showing the potential for involvement of crates in transmission. Inclusion of a silver ion biocide in poultry transportation crates to levels demonstrating acceptable antibacterial activity in vitro reduces the level of bacterial contamination during normal crate use compared to standard crates. Molecular analysis of Campylobacter isolates indicated a change in genetic structure of the population with respect to the poultry-processing plant sanitization practice. The application of a sustainable antimicrobial to components of poultry processing may contribute to reducing the levels of Campylobacter

  5. Inversion of lithium heparin gel tubes after centrifugation is a significant source of bias in clinical chemistry testing.

    Science.gov (United States)

    Lippi, Giuseppe; Salvagno, Gian Luca; Danese, Elisa; Lima-Oliveira, Gabriel; Brocco, Giorgio; Guidi, Gian Cesare

    2014-09-25

    This study was planned to establish whether random orientation of gel tubes after centrifugation may impair sample quality. Eight gel tubes were collected from 17 volunteers: 2 Becton Dickinson (BD) serum tubes, 2 Terumo serum tubes, 2 BD lithium heparin tubes and 2 Terumo lithium heparin tubes. One patient's tube for each category was kept in a vertical, closure-up position for 90 min ("upright"), whereas paired tubes underwent bottom-up inversion every 15 min, for 90 min ("inverted"). Immediately after this period of time, 14 clinical chemistry analytes, serum indices and complete blood count were then assessed in all tubes. Significant increases were found for phosphate and lipaemic index in all inverted tubes, along with AST, calcium, cholesterol, LDH, potassium, hemolysis index, leukocytes, erythrocytes and platelets limited to lithium heparin tubes. The desirable quality specifications were exceeded for AST, LDH, and potassium in inverted lithium heparin tubes. Residual leukocytes, erythrocytes, platelets and cellular debris were also significantly increased in inverted lithium heparin tubes. Lithium heparin gel tubes should be maintained in a vertical, closure-up position after centrifugation. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. [Accuracy of attenuation coefficient obtained by 137Cs single-transmission scanning in PET: comparison with conventional germanium line source].

    Science.gov (United States)

    Matsumoto, Keiichi; Kitamura, Keishi; Mizuta, Tetsuro; Shimizu, Keiji; Murase, Kenya; Senda, Michio

    2006-02-20

    Transmission scanning can be successfully performed with a Cs-137 single-photon-emitting point source for three-dimensional PET imaging. This method was effective for postinjection transmission scanning because of differences in physical energy. However, scatter contamination in the transmission data lowers measured attenuation coefficients. The purpose of this study was to investigate the accuracy of the influence of object scattering by measuring the attenuation coefficients on the transmission images. We also compared the results with the conventional germanium line source method. Two different types of PET scanner, the SET-3000 G/X (Shimadzu Corp.) and ECAT EXACT HR(+) (Siemens/CTI) , were used. For the transmission scanning, the SET-3000 G/X and ECAT HR(+) were the Cs-137 point source and Ge-68/Ga-68 line source, respectively. With the SET-3000 G/X, we performed transmission measurement at two energy gate settings, the standard 600-800 keV as well as 500-800 keV. The energy gate setting of the ECAT HR(+) was 350-650 keV. The effects of scattering in a uniform phantom with different cross-sectional areas ranging from 201 cm(2) to 314 cm(2) to 628 cm(2) (apposition of the two 20 cm diameter phantoms) and 943 cm(2) (stacking of the three 20 cm diameter phantoms) were acquired without emission activity. First, we evaluated the attenuation coefficients of the two different types of transmission scanning using region of interest (ROI) analysis. In addition, we evaluated the attenuation coefficients with and without segmentation for Cs-137 transmission images using the same analysis. The segmentation method was a histogram-based soft-tissue segmentation process that can also be applied to reconstructed transmission images. In the Cs-137 experiment, the maximum underestimation was 3% without segmentation, which was reduced to less than 1% with segmentation at the center of the largest phantom. In the Ge-68/Ga-68 experiment, the difference in mean attenuation

  7. Accuracy of attenuation coefficient obtained by 137Cs single-transmission scanning in PET. Comparison with conventional germanium line source

    International Nuclear Information System (INIS)

    Matsumoto, Keiichi; Shimizu, Keiji; Senda, Michio; Kitamura, Keishi; Mizuta, Tetsuro; Murase, Kenya

    2006-01-01

    Transmission scanning can be successfully performed with a Cs-137 single-photon-emitting point source for three-dimensional PET imaging. This method was effective for postinjection transmission scanning because of differences in physical energy. However, scatter contamination in the transmission data lowers measured attenuation coefficients. The purpose of this study was to investigate the accuracy of the influence of object scattering by measuring the attenuation coefficients on the transmission images. We also compared the results with the conventional germanium line source method. Two different types of PET scanner, the SET-3000 G/X (Shimadzu Corp.) and ECAT EXACT HR + (Siemens/CTI), were used. For the transmission scanning, the SET-3000 G/X and ECAT HR + were the Cs-137 point source and Ge-68/Ga-68 line source, respectively. With the SET-3000 G/X, we performed transmission measurement at two energy gate settings, the standard 600-800 keV as well as 500-800 keV. The energy gate setting of the ECAT HR 2 + was 350-650 keV. The effects of scattering in a uniform phantom with different cross-sectional areas ranging from 201 cm 2 to 314 cm 2 to 628 cm 2 (apposition of the two 20 cm diameter phantoms) and 943 cm 2 (stacking of the three 20 cm diameter phantoms) were acquired without emission activity. First, we evaluated the attenuation coefficients of the two different types of transmission scanning using region of interest (ROI) analysis. In addition, we evaluated the attenuation coefficients with and without segmentation for Cs-137 transmission images using the same analysis. The segmentation method was a histogram-based soft-tissue segmentation process that can also be applied to reconstructed transmission images. In the Cs-137 experiment, the maximum underestimation was 3% without segmentation, which was reduced to less than 1% with segmentation at the center of the largest phantom. In the Ge-68/Ga-68 experiment, the difference in mean attenuation coefficients

  8. Source Anonymity in WSNs against Global Adversary Utilizing Low Transmission Rates with Delay Constraints

    Directory of Open Access Journals (Sweden)

    Anas Bushnag

    2016-06-01

    Full Text Available Wireless sensor networks (WSN are deployed for many applications such as tracking and monitoring of endangered species, military applications, etc. which require anonymity of the origin, known as Source Location Privacy (SLP. The aim in SLP is to prevent unauthorized observers from tracing the source of a real event by analyzing the traffic in the network. Previous approaches to SLP such as Fortified Anonymous Communication Protocol (FACP employ transmission of real or fake packets in every time slot, which is inefficient. To overcome this shortcoming, we developed three different techniques presented in this paper. Dummy Uniform Distribution (DUD, Dummy Adaptive Distribution (DAD and Controlled Dummy Adaptive Distribution (CAD were developed to overcome the anonymity problem against a global adversary (which has the capability of analyzing and monitoring the entire network. Most of the current techniques try to prevent the adversary from perceiving the location and time of the real event whereas our proposed techniques confuse the adversary about the existence of the real event by introducing low rate fake messages, which subsequently lead to location and time privacy. Simulation results demonstrate that the proposed techniques provide reasonable delivery ratio, delay, and overhead of a real event's packets while keeping a high level of anonymity. Three different analysis models are conducted to verify the performance of our techniques. A visualization of the simulation data is performed to confirm anonymity. Further, neural network models are developed to ensure that the introduced techniques preserve SLP. Finally, a steganography model based on probability is implemented to prove the anonymity of the techniques.

  9. A beam optics study of a modular multi-source X-ray tube for novel computed tomography applications

    Science.gov (United States)

    Walker, Brandon J.; Radtke, Jeff; Chen, Guang-Hong; Eliceiri, Kevin W.; Mackie, Thomas R.

    2017-10-01

    A modular implementation of a scanning multi-source X-ray tube is designed for the increasing number of multi-source imaging applications in computed tomography (CT). An electron beam array coupled with an oscillating magnetic deflector is proposed as a means for producing an X-ray focal spot at any position along a line. The preliminary multi-source model includes three thermionic electron guns that are deflected in tandem by a slowly varying magnetic field and pulsed according to a scanning sequence that is dependent on the intended imaging application. Particle tracking simulations with particle dynamics analysis software demonstrate that three 100 keV electron beams are laterally swept a combined distance of 15 cm over a stationary target with an oscillating magnetic field of 102 G perpendicular to the beam axis. Beam modulation is accomplished using 25 μs pulse widths to a grid electrode with a reverse gate bias of -500 V and an extraction voltage of +1000 V. Projected focal spot diameters are approximately 1 mm for 138 mA electron beams and the stationary target stays within thermal limits for the 14 kW module. This concept could be used as a research platform for investigating high-speed stationary CT scanners, for lowering dose with virtual fan beam formation, for reducing scatter radiation in cone-beam CT, or for other industrial applications.

  10. Optical fiber sources and transmission controls for multi-Tb/s systems

    Science.gov (United States)

    Nowak, George Adelbert

    The accelerating demand for bandwidth capacity in backbone links of terrestrial communications systems is projected to exceed 1Tb/s by 2002. Lightwave carrier frequencies and fused-silica optical fibers provide the natural combination of high passband frequencies and low- loss medium to satisfy this evolving demand for bandwidth capacity. This thesis addresses three key technologies for enabling multi-Tb/s optical fiber communication systems. The first technology is a broadband source based on supercontinuum generation in optical fiber. Using a single modelocked laser with output pulsewidths of 0.5psec pulses, we generate in ~2m of dispersion-shifted fiber more that 200nm of spectral continuum in the vicinity of 1550nm that is flat to better than +/- 0.5 dB over more than 60nm. The short fiber length prevents degradation of timing jitter of the seed pulses and preserves coherence of the continuum by inhibiting environmental perturbations and mapping of random noise from the vicinity of the input pulse across the continuum. Through experiments and simulations, we find that the continuum characteristics result from 3rd order dispersion effects on higher-order soliton compression. We determine optimal fiber properties to provide desired continuum broadness and flatness for given input pulsewidth and energy conditions. The second technology is a novel delay-shifted nonlinear optical loop mirror (DS-NOLM) that performs a transmission control function by serving as an intensity filter and frequency compensator for 4ps soliton transmission over 75km of standard dispersion fiber, with 25km spacing between amplifiers, by filtering the dispersive waves and compensating for Raman-induced soliton self-frequency shift. The third technology is all-fiber wavelength conversion employing induced modulational instability. We obtain wavelength conversion over 40nm with a peak conversion efficiency of 28dB using 600mW pump pulses in 720m of high-nonlinearity optical fiber. We show

  11. English language YouTube videos as a source of lead poisoning-related information: a cross-sectional study.

    Science.gov (United States)

    Basch, Corey H; Jackson, Ashley M; Yin, Jingjing; Hammond, Rodney N; Adhikari, Atin; Fung, Isaac Chun-Hai

    2017-07-01

    Exposure to lead is detrimental to children's development. YouTube is a form of social media through which people may learn about lead poisoning. The aim of this cross-sectional study was to analyze the variation in lead poisoning-related YouTube contents between different video sources. The 100 most viewed lead poisoning-related videos were manually coded, among which, 50 were consumer-generated, 19 were created by health care professionals, and 31 were news. The 100 videos had a total of more than 8.9 million views, with news videos accounting for 63% of those views. The odds of mentioning what lead poisoning is, how to remove lead, and specifically mentioning the danger in ages 1-5 because of rapid growth among videos created by health care professionals were 7.28 times (Odds ratio, OR = 7.28, 95% CI, 2.09, 25.37, p = 0.002); 6.83 times (OR = 6.83, 95% CI, 2.05, 22.75, p = 0.002) and 9.14 times (OR = 9.14, CI, 2.05, 40.70, p = 0.004) that of consumer-generated videos, respectively. In this study, professional videos had more accurate information regarding lead but their videos were less likely to be viewed compared to consumer-generated videos and news videos. If professional videos about lead poisoning can attract more viewers, more people would be better informed and could possibly influence policy agendas, thereby helping communities being affected by lead exposure.

  12. A revisit to self-excited push pull vacuum tube radio frequency oscillator for ion sources and power measurements

    International Nuclear Information System (INIS)

    Hlondo, L. R.; Lalremruata, B.; Punte, L. R. M.; Rebecca, L.; Lalnunthari, J.; Thanga, H. H.

    2016-01-01

    Self-excited push-pull vacuum tube oscillator is one of the most commonly used oscillators in radio frequency (RF)-ion plasma sources for generation of ions using radio frequency. However, in spite of its fundamental role in the process of plasma formation, the working and operational characteristics are the most frequently skip part in the descriptions of RF ion sources in literatures. A more detailed treatment is given in the present work on the RF oscillator alone using twin beam power tetrodes 829B and GI30. The circuit operates at 102 MHz, and the oscillation conditions, stability in frequency, and RF output power are studied and analyzed. A modified form of photometric method and RF peak voltage detection method are employed to study the variation of the oscillator output power with plate voltage. The power curves obtained from these measurements are quadratic in nature and increase with increase in plate voltage. However, the RF output power as measured by photometric methods is always less than the value calculated from peak voltage measurements. This difference is due to the fact that the filament coil of the ordinary light bulb used as load/detector in photometric method is not a perfect inductor. The effect of inductive reactance on power transfer to load was further investigated and a technique is developed to estimate the amount of power correction needed in the photometric measurement result.

  13. Counting the dead to determine the source and transmission of the marine herpesvirus OsHV-1 in Crassostrea gigas.

    Science.gov (United States)

    Whittington, Richard J; Paul-Pont, Ika; Evans, Olivia; Hick, Paul; Dhand, Navneet K

    2018-04-10

    Marine herpesviruses are responsible for epizootics in economically, ecologically and culturally significant taxa. The recent emergence of microvariants of Ostreid herpesvirus 1 (OsHV-1) in Pacific oysters Crassostrea gigas has resulted in socioeconomic losses in Europe, New Zealand and Australia however, there is no information on their origin or mode of transmission. These factors need to be understood because they influence the way the disease may be prevented and controlled. Mortality data obtained from experimental populations of C. gigas during natural epizootics of OsHV-1 disease in Australia were analysed qualitatively. In addition we compared actual mortality data with those from a Reed-Frost model of direct transmission and analysed incubation periods using Sartwell's method to test for the type of epizootic, point source or propagating. We concluded that outbreaks were initiated from an unknown environmental source which is unlikely to be farmed oysters in the same estuary. While direct oyster-to-oyster transmission may occur in larger oysters if they are in close proximity (< 40 cm), it did not explain the observed epizootics, point source exposure and indirect transmission being more common and important. A conceptual model is proposed for OsHV-1 index case source and transmission, leading to endemicity with recurrent seasonal outbreaks. The findings suggest that prevention and control of OsHV-1 in C. gigas will require multiple interventions. OsHV-1 in C. gigas, which is a sedentary animal once beyond the larval stage, is an informative model when considering marine host-herpesvirus relationships.

  14. Non-proximate mass spectrometry using a heated 1-m long PTFE tube and an air-tight APCI ion source

    International Nuclear Information System (INIS)

    Usmanov, Dilshadbek T.; Hiraoka, Kenzo; Wada, Hiroshi; Matsumura, Masaya; Sanada-Morimura, Sachiyo; Nonami, Hiroshi; Yamabe, Shinichi

    2017-01-01

    Direct and rapid trace-level gas analysis is highly needed in various fields such as safety and security, quality control, food analysis, and forensic medicine. In many cases, the real samples are bulky and are not accessible to the space-limited ion source of the mass spectrometer. In order to circumvent this problem, we developed an airtight atmospheric-pressure chemical ionization (APCI) ion source equipped with a flexible 1-m-long, 2-mm-i.d. PTFE sniffing tube. The ambient air bearing sample gas was sucked into the heated PTFE tube (130 °C) and was transported to the air-tight ion source without using any extra pumping system or a Venturi device. Analytes were ionized by an ac corona discharge located at 1.5 mm from the inlet of the mass spectrometer. By using the airtight ion source, all the ionized gas in the ion source was introduced into the vacuum of the mass spectrometer via only the evacuation of the mass spectrometer (1.6 l min"−"1). Sub-pg limits of detection were obtained for carbaryl and trinitrotoluene. Owing to its flexibility and high sensitivity, the sniffing tube coupled with a mass spectrometer can be used as the stethoscope for the high-sensitive gas analysis. The experimental results obtained for drugs, hydrogen peroxide and small alkanes were discussed by DFT calculations. - Highlights: • Non-proximate mass spectrometry for the trace-level gas analysis was developed. • Using a 1-m long flexible PTFE tube, it can be applicable to complicated-shape real-world samples. • By atmospheric pressure chemical ionization in the airtight ion source, sub-pg limits of detection were attained. • Adsorption of less-volatility compounds was negligible with the tube temperature at 130° C. • Novel experimental results obtained were fully examined by density functional theory calculations.

  15. Non-proximate mass spectrometry using a heated 1-m long PTFE tube and an air-tight APCI ion source

    Energy Technology Data Exchange (ETDEWEB)

    Usmanov, Dilshadbek T. [Clean Energy Research Center, University of Yamanashi, Takeda-4, Kofu, Yamanashi, 400-8511 (Japan); Institute of Ion-Plasma and Laser Technologies, Durmon Yoli Street 33, 100125, Tashkent (Uzbekistan); Hiraoka, Kenzo, E-mail: hiraoka@yamanashi.ac.jp [Clean Energy Research Center, University of Yamanashi, Takeda-4, Kofu, Yamanashi, 400-8511 (Japan); Wada, Hiroshi [Kyushu Okinawa Agricultural Research Center, National Agriculture and Food Research Organization, 496 Izumi, Chikugo, Fukuoka 833-0041 (Japan); Matsumura, Masaya; Sanada-Morimura, Sachiyo [Kyushu Okinawa Agricultural Research Center, National Agriculture and Food Research Organization, Suya 2421, shiKo, Kumamoto 861-1192 (Japan); Nonami, Hiroshi [Plant Biophysics/Biochemistry Research Laboratory, Faculty of Agriculture, Ehime University, 3-5-7 T Tarumi, 790-0905, Matsuyama (Japan); Yamabe, Shinichi, E-mail: yamabesh@gmail.com [Department of Material Science, Nara Institute of Science and Technology, Takayama-cho, 8916-5, Ikoma, Nara, 630−0101 (Japan)

    2017-06-22

    Direct and rapid trace-level gas analysis is highly needed in various fields such as safety and security, quality control, food analysis, and forensic medicine. In many cases, the real samples are bulky and are not accessible to the space-limited ion source of the mass spectrometer. In order to circumvent this problem, we developed an airtight atmospheric-pressure chemical ionization (APCI) ion source equipped with a flexible 1-m-long, 2-mm-i.d. PTFE sniffing tube. The ambient air bearing sample gas was sucked into the heated PTFE tube (130 °C) and was transported to the air-tight ion source without using any extra pumping system or a Venturi device. Analytes were ionized by an ac corona discharge located at 1.5 mm from the inlet of the mass spectrometer. By using the airtight ion source, all the ionized gas in the ion source was introduced into the vacuum of the mass spectrometer via only the evacuation of the mass spectrometer (1.6 l min{sup −1}). Sub-pg limits of detection were obtained for carbaryl and trinitrotoluene. Owing to its flexibility and high sensitivity, the sniffing tube coupled with a mass spectrometer can be used as the stethoscope for the high-sensitive gas analysis. The experimental results obtained for drugs, hydrogen peroxide and small alkanes were discussed by DFT calculations. - Highlights: • Non-proximate mass spectrometry for the trace-level gas analysis was developed. • Using a 1-m long flexible PTFE tube, it can be applicable to complicated-shape real-world samples. • By atmospheric pressure chemical ionization in the airtight ion source, sub-pg limits of detection were attained. • Adsorption of less-volatility compounds was negligible with the tube temperature at 130° C. • Novel experimental results obtained were fully examined by density functional theory calculations.

  16. Handling of radiation emergency involving accidental detachment of 20 Ci iridium-192 source in a guide tube of a radiographic equipment in industrial radiography site

    International Nuclear Information System (INIS)

    Zaparde, S.P.; Murthy, B.K.S.; Vora, V.B.; Subramanian, G.

    1979-01-01

    The source capsule containing about 17.2 Ci of iridium-192 got accidently unscrewed in a guide tube of a gamma radiography equipment while carrying out the radiography of the spiral casing at construction site of a Hydroelectric Power Station. Immediately after the incident about 10 meter distance all around the spiral casing was cordoned off. The unscrewed capsule along with the source pellet was transferred to a lead container by raising the closed end of the guide tube of about 1/2 meters in length. The source pencil cable and cap of source capsule were separated from the source pellet. The source pellet was further shielded by a steel container and lead sheets. The source pellet was reloaded in the source capsule with limited facilities available at the work site. The source capsule cap was perfectly screwed by standing behind the L bench temporarily constructed out of lead sheets for the above jobs. During the above operation, the person received a whole body dose of 2000 mR and extrimety dose of 3000 mR. Handling of one more radiation emergency of similar type is described. A few appliances designed and fabricated for use in such emergencies are briefly described. (auth.)

  17. Reduced dose uncertainty in MRI-based polymer gel dosimetry using parallel RF transmission with multiple RF sources

    International Nuclear Information System (INIS)

    Sang-Young Kim; Jung-Hoon Lee; Jin-Young Jung; Do-Wan Lee; Seu-Ran Lee; Bo-Young Choe; Hyeon-Man Baek; Korea University of Science and Technology, Daejeon; Dae-Hyun Kim; Jung-Whan Min; Ji-Yeon Park

    2014-01-01

    In this work, we present the feasibility of using a parallel RF transmit with multiple RF sources imaging method (MultiTransmit imaging) in polymer gel dosimetry. Image quality and B 1 field homogeneity was statistically better in the MultiTransmit imaging method than in conventional single source RF transmission imaging method. In particular, the standard uncertainty of R 2 was lower on the MultiTransmit images than on the conventional images. Furthermore, the MultiTransmit measurement showed improved dose resolution. Improved image quality and B 1 homogeneity results in reduced dose uncertainty, thereby suggesting the feasibility of MultiTransmit MR imaging in gel dosimetry. (author)

  18. Epidemiologic study of neural tube defects in Los Angeles County. I. Prevalence at birth based on multiple sources of case ascertainment

    Energy Technology Data Exchange (ETDEWEB)

    Sever, L.E. (Pacific Northwest Lab., Richland, WA); Sanders, M.; Monsen, R.

    1982-01-01

    Epidemiologic studies of the neural tube defects (NTDs), anencephalus and spina bifida, have for the most part been based on single sources of case ascertainment in past studies. The present investigation attempts total ascertainment of NTD cases in the newborn population of Los Angeles County residents for the period 1966 to 1972. Design of the study, sources of data, and estimates of prevalence rates based on single and multiple sources of case ascertainment are here discussed. Anencephalus cases totaled 448, spina bifida 442, and encephalocele 72, giving prevalence rates of 0.52, 0.51, and 0.08 per 1000 total births, respectively, for these neural tube defects - rates considered to be low. The Los Angeles County prevalence rates are compared with those of other recent North American studies and support is provided for earlier suggestions of low rates on the West Coast.

  19. Left or right? Sources of political orientation: the roles of genetic factors, cultural transmission, assortative mating, and personality.

    Science.gov (United States)

    Kandler, Christian; Bleidorn, Wiebke; Riemann, Rainer

    2012-03-01

    In this study, we used an extended twin family design to investigate the influences of genetic and cultural transmission as well as different sources of nonrandom mating on 2 core aspects of political orientation: acceptance of inequality and rejecting system change. In addition, we studied the sources of phenotypic links between Big Five personality traits and political beliefs using self- and other reports. Data of 1,992 individuals (224 monozygotic and 166 dizygotic twin pairs, 92 unmatched twins, 530 spouses of twins, 268 fathers, and 322 mothers) were analyzed. Genetically informative analyses showed that political attitudes are genetically but not environmentally transmitted from parents to offspring and that a substantial proportion of this genetic variance can be accounted for by genetic variance in personality traits. Beyond genetic effects and genotypic assortative mating, generation-specific environmental sources act to increase twins' and spouses' resemblance in political beliefs. The results suggest multiple sources of political orientations in a modern democracy.

  20. Transmission-grid requirements with scattered and fluctuating renewable electricity-sources

    DEFF Research Database (Denmark)

    Østergaard, Poul Alberg

    2003-01-01

    The article analysis the requirements of the transmission grids in a year 2020 situation with power balancing (matching production and consumption)as it is now on the few large power plants, and a year 2020 situation with geographically-scattered power balancing using e.g. CHP plants, heat pumps...

  1. Low tube voltage dual source computed tomography to reduce contrast media doses in adult abdomen examinations: A phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Thor, Daniel [Department of Diagnostic Medical Physics, Karolinska University Hospital, Stockholm 14186 (Sweden); Brismar, Torkel B., E-mail: torkel.brismar@gmail.com; Fischer, Michael A. [Department of Clinical Science, Intervention and Technology at Karolinska Institutet and Department of Radiology, Karolinska University Hospital in Huddinge, Stockholm 14186 (Sweden)

    2015-09-15

    Purpose: To evaluate the potential of low tube voltage dual source (DS) single energy (SE) and dual energy (DE) computed tomography (CT) to reduce contrast media (CM) dose in adult abdominal examinations of various sizes while maintaining soft tissue and iodine contrast-to-noise ratio (CNR). Methods: Four abdominal phantoms simulating a body mass index of 16 to 35 kg/m{sup 2} with four inserted syringes of 0, 2, 4, and 8 mgI/ml CM were scanned using a 64-slice DS-CT scanner. Six imaging protocols were used; one single source (SS) reference protocol (120 kV, 180 reference mAs), four low kV SE protocols (70 and 80 kV using both SS and DS), and one DE protocol at 80/140 kV. Potential CM reduction with unchanged CNRs relative to the 120 kV protocol was calculated along with the corresponding increase in radiation dose. Results: The potential contrast media reductions were determined to be approximately 53% for DS 70 kV, 51% for SS 70 kV, 44% for DS 80 kV, 40% for SS 80 kV, and 20% for DE (all differences were significant, P < 0.05). Constant CNR could be achieved by using DS 70 kV for small to medium phantom sizes (16–26 kg/m{sup 2}) and for all sizes (16–35 kg/m{sup 2}) when using DS 80 kV and DE. Corresponding radiation doses increased by 60%–107%, 23%–83%, and 6%–12%, respectively. Conclusions: DS single energy CT can be used to reduce CM dose by 44%–53% with maintained CNR in adult abdominal examinations at the cost of an increased radiation dose. DS dual-energy CT allows reduction of CM dose by 20% at similar radiation dose as compared to a standard 120 kV single source.

  2. Monte Carlo simulations and radiation dosimetry measurements of 142Pr capillary tube-based radioactive implant (CTRI). A new structure for brachytherapy sources

    International Nuclear Information System (INIS)

    Bakht, M.K.; Haddadi, A.; Sadeghi, M.; Ahmadi, S.J.; Sadjadi, S.S.; Tenreiro, C.

    2013-01-01

    Previously, a promising β - -emitting praseodymium-142 glass seed was proposed for brachytherapy of prostate cancer. In accordance with the previous study, a 142 Pr capillary tube-based radioactive implant (CTRI) was suggested as a source with a new structure to enhance application of β - -emitting radioisotopes such as 142 Pr in brachytherapy. Praseodymium oxide powder was encapsulated in a glass capillary tube. Then, a thin and flexible fluorinated ethylene propylene Teflon layer sealed the capillary tube. The source was activated in the Tehran Research Reactor by the 141 Pr(n, γ) 142 Pr reaction. Measurements of the dosimetric parameters were performed using GafChromic radiochromic film. In addition, the dose rate distribution of 142 Pr CTRI was calculated by modeling 142 Pr source in a water phantom using Monte Carlo N-Particle Transport (MCNP5) Code. The active source was unreactive and did not leak in water. In comparison with the earlier proposed 142 Pr seed, the suggested source showed similar desirable dosimetric characteristics. Moreover, the 142 Pr CTRI production procedure may be technically and economically more feasible. The mass of praseodymium in CTRI structure could be greater than that of the 142 Pr glass seed; therefore, the required irradiation time and the neutron flux could be reduced. A 142 Pr CTRI was proposed for brachytherapy of prostate cancer. The dosimetric calculations by the experimental measurements and Monte Carlo simulation were performed to fulfill the requirements according to the American Association of Physicists in Medicine recommendations before the clinical use of new brachytherapy sources. The characteristics of the suggested source were compared with those of the previously proposed 142 Pr glass seed. (author)

  3. Microwave plasma ion sources for selected ion flow tube mass spectrometry: Optimizing their performance and detection limits for trace gas analysis

    Czech Academy of Sciences Publication Activity Database

    Španěl, Patrik; Dryahina, Kseniya; Smith, D.

    2007-01-01

    Roč. 267, 1-3 (2007), s. 117-124 ISSN 1387-3806 R&D Projects: GA ČR GA202/06/0776 Institutional research plan: CEZ:AV0Z40400503 Keywords : microwave plasma ion source * selected ion flow tube mass spectrometry * SIFT-MS * breath analysis Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.411, year: 2007

  4. Broadband transmission grating spectrometer for measuring the emission spectrum of EUV sources

    NARCIS (Netherlands)

    Bayraktar, Muharrem; Bastiaens, Hubertus M.J.; Bruineman, Caspar; Vratzov, Boris; Bijkerk, Frederik

    2016-01-01

    Extreme ultraviolet (EUV) light sources and their optimization for emission within a narrow wavelength band are essential in applications such as photolithography. Most light sources however also emit radiation outside this wavelength band and have a spectrum extending up to deep ultraviolet (DUV)

  5. Transmission of tularemia from a water source by transstadial maintenance in a mosquito vector

    Science.gov (United States)

    Bäckman, Stina; Näslund, Jonas; Forsman, Mats; Thelaus, Johanna

    2015-01-01

    Mosquitoes are thought to function as mechanical vectors of Francisella tularensis subspecies holarctica (F. t. holarctica) causing tularemia in humans. We investigated the clinical relevance of transstadially maintained F. t. holarctica in mosquitoes. Aedes egypti larvae exposed to a fully virulent F. t. holarctica strain for 24 hours, were allowed to develop into adults when they were individually homogenized. Approximately 24% of the homogenates tested positive for F. t. DNA in PCR. Mice injected with the mosquito homogenates acquired tularemia within 5 days. This novel finding demonstrates the possibility of transmission of bacteria by adult mosquitoes having acquired the pathogen from their aquatic larval habitats.

  6. Cross-talk in straw tube chambers

    Energy Technology Data Exchange (ETDEWEB)

    Marzec, J. E-mail: janusz.marzec@ire.pw.edu.pl

    2003-05-11

    An analytical model of the signal transmission between neighboring straw tubes with resistive cathodes (cross-talk) is presented. The dependence of the cross-talk level on the cathode resistance, tube length, particle detection point, the distance of the tube from the shielding planes, and termination of the tube ends is analyzed.

  7. Cross-talk in straw tube chambers

    International Nuclear Information System (INIS)

    Marzec, J.

    2003-01-01

    An analytical model of the signal transmission between neighboring straw tubes with resistive cathodes (cross-talk) is presented. The dependence of the cross-talk level on the cathode resistance, tube length, particle detection point, the distance of the tube from the shielding planes, and termination of the tube ends is analyzed

  8. Development of a high brightness ultrafast Transmission Electron Microscope based on a laser-driven cold field emission source.

    Science.gov (United States)

    Houdellier, F; Caruso, G M; Weber, S; Kociak, M; Arbouet, A

    2018-03-01

    We report on the development of an ultrafast Transmission Electron Microscope based on a cold field emission source which can operate in either DC or ultrafast mode. Electron emission from a tungsten nanotip is triggered by femtosecond laser pulses which are tightly focused by optical components integrated inside a cold field emission source close to the cathode. The properties of the electron probe (brightness, angular current density, stability) are quantitatively determined. The measured brightness is the largest reported so far for UTEMs. Examples of imaging, diffraction and spectroscopy using ultrashort electron pulses are given. Finally, the potential of this instrument is illustrated by performing electron holography in the off-axis configuration using ultrashort electron pulses. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Preparation of Ag-containing diamond-like carbon films on the interior surface of tubes by a combined method of plasma source ion implantation and DC sputtering

    Science.gov (United States)

    Hatada, R.; Flege, S.; Bobrich, A.; Ensinger, W.; Dietz, C.; Baba, K.; Sawase, T.; Watamoto, T.; Matsutani, T.

    2014-08-01

    Adhesive diamond-like carbon (DLC) films can be prepared by plasma source ion implantation (PSII), which is also suitable for the treatment of the inner surface of a tube. Incorporation of a metal into the DLC film provides a possibility to change the characteristics of the DLC film. One source for the metal is DC sputtering. In this study PSII and DC sputtering were combined to prepare DLC films containing low concentrations of Ag on the interior surfaces of stainless steel tubes. A DLC film was deposited using a C2H4 plasma with the help of an auxiliary electrode inside of the tube. This electrode was then used as a target for the DC sputtering. A mixture of the gases Ar and C2H4 was used to sputter the silver. By changing the gas flow ratios and process time, the resulting Ag content of the films could be varied. Sample characterizations were performed by X-ray photoelectron spectroscopy, secondary ion mass spectrometry, atomic force microscopy and Raman spectroscopy. Additionally, a ball-on-disk test was performed to investigate the tribological properties of the films. The antibacterial activity was determined using Staphylococcus aureus bacteria.

  10. Neutron resonance transmission spectroscopy with high spatial and energy resolution at the J-PARC pulsed neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Tremsin, A.S., E-mail: ast@ssl.berkeley.edu [University of California at Berkeley, 7 Gauss Way, Berkeley, CA 94720 (United States); Shinohara, T.; Kai, T.; Ooi, M. [Japan Atomic Energy Agency, 2–4 Shirakata-shirane, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Kamiyama, T.; Kiyanagi, Y.; Shiota, Y. [Hokkaido University, Kita 13 Nishi 8 Kita-ku, Sapporo-shi, Hokkaido 060-8628 (Japan); McPhate, J.B.; Vallerga, J.V.; Siegmund, O.H.W. [University of California at Berkeley, 7 Gauss Way, Berkeley, CA 94720 (United States); Feller, W.B. [NOVA Scientific, Inc., 10 Picker Rd., Sturbridge, MA 01566 (United States)

    2014-05-11

    The sharp variation of neutron attenuation at certain energies specific to particular nuclides (the lower range being from ∼1 eV up to ∼1 keV), can be exploited for the remote mapping of element and/or isotope distributions, as well as temperature probing, within relatively thick samples. Intense pulsed neutron beam-lines at spallation sources combined with a high spatial, high-timing resolution neutron counting detector, provide a unique opportunity to measure neutron transmission spectra through the time-of-flight technique. We present the results of experiments where spatially resolved neutron resonances were measured, at energies up to 50 keV. These experiments were performed with the intense flux low background NOBORU neutron beamline at the J-PARC neutron source and the high timing resolution (∼20 ns at epithermal neutron energies) and spatial resolution (∼55 µm) neutron counting detector using microchannel plates coupled to a Timepix electronic readout. Simultaneous element-specific imaging was carried out for several materials, at a spatial resolution of ∼150 µm. The high timing resolution of our detector combined with the low background beamline, also enabled characterization of the neutron pulse itself – specifically its pulse width, which varies with neutron energy. The results of our measurements are in good agreement with the predicted results for the double pulse structure of the J-PARC facility, which provides two 100 ns-wide proton pulses separated by 600 ns, broadened by the neutron energy moderation process. Thermal neutron radiography can be conducted simultaneously with resonance transmission spectroscopy, and can reveal the internal structure of the samples. The transmission spectra measured in our experiments demonstrate the feasibility of mapping elemental distributions using this non-destructive technique, for those elements (and in certain cases, specific isotopes), which have resonance energies below a few keV, and with lower

  11. Automated tube voltage selection for radiation dose and contrast medium reduction at coronary CT angiography using 3{sup rd} generation dual-source CT

    Energy Technology Data Exchange (ETDEWEB)

    Mangold, Stefanie [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Eberhard-Karls University Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany); Wichmann, Julian L. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Schoepf, U.J. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Medical University of South Carolina, Division of Cardiology, Department of Medicine, Charleston, SC (United States); Poole, Zachary B.; Varga-Szemes, Akos; De Cecco, Carlo N. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Canstein, Christian [Siemens Medical Solutions, Malvern, PA (United States); Caruso, Damiano [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); University of Rome ' ' Sapienza' ' , Department of Radiological Sciences, Oncology and Pathology, Rome (Italy); Bamberg, Fabian; Nikolaou, Konstantin [Eberhard-Karls University Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany)

    2016-10-15

    To investigate the relationship between automated tube voltage selection (ATVS) and body mass index (BMI) and its effect on image quality and radiation dose of coronary CT angiography (CCTA). We evaluated 272 patients who underwent CCTA with 3{sup rd} generation dual-source CT (DSCT). Prospectively ECG-triggered spiral acquisition was performed with automated tube current selection and advanced iterative reconstruction. Tube voltages were selected by ATVS (70-120 kV). BMI, effective dose (ED), and vascular attenuation in the coronary arteries were recorded. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Five-point scales were used for subjective image quality analysis. Image quality was rated good to excellent in 98.9 % of examinations without significant differences for proximal and distal attenuation (all p ≥.0516), whereas image noise was rated significantly higher at 70 kV compared to ≥100 kV (all p <.0266). However, no significant differences were observed in SNR or CNR at 70-120 kV (all p ≥.0829). Mean ED at 70-120 kV was 1.5 ± 1.2 mSv, 2.4 ± 1.5 mSv, 3.6 ± 2.7 mSv, 5.9 ± 4.0 mSv, 7.9 ± 4.2 mSv, and 10.7 ± 4.1 mSv, respectively (all p ≤.0414). Correlation analysis showed a moderate association between tube voltage and BMI (r =.639). ATVS allows individual tube voltage adaptation for CCTA performed with 3{sup rd} generation DSCT, resulting in significantly decreased radiation exposure while maintaining image quality. (orig.)

  12. Correlated Sources in Distributed Networks--Data Transmission, Common Information Characterization and Inferencing

    Science.gov (United States)

    Liu, Wei

    2011-01-01

    Correlation is often present among observations in a distributed system. This thesis deals with various design issues when correlated data are observed at distributed terminals, including: communicating correlated sources over interference channels, characterizing the common information among dependent random variables, and testing the presence of…

  13. Mycobacterium bovis infection in a young Dutch adult : transmission from an elderly human source?

    NARCIS (Netherlands)

    Akkerman, Onno; van der Loo, Kees; Nijmeijer, Dirk; van der Werf, Tjip; Mulder, Bert; Kremer, Kristin; van Soolingen, Dick; van der Zanden, Adri

    A young female health professional was diagnosed with pulmonary tuberculosis caused by Mycobacterium bovis. Source finding and contact tracing was initiated by the regional municipal health service using both tuberculin skin test and QuantiFERON(A (R))-TB Gold (QFT-GIT (IGRA). The strain appeared

  14. 252Cf-source-correlated transmission measurements for uranyl fluoride deposit in a 24-in.-OD process pipe

    International Nuclear Information System (INIS)

    Uckan, T.; Mihalczo, J.T.; Valentine, T.E.; Mullens, J.A.

    1998-01-01

    Characterization of a hydrated uranyl fluoride (UO 2 F 2 ·nH 2 O) deposit in a 17-ft-long, 24-in.-OD process pipe at the former Oak Ridge Gaseous Diffusion Plant was successfully performed by using 252 Cf-source-correlated time-of-flight (TOF) transmission measurements. These measurements of neutrons and gamma rays through the pipe from an external 2521 Cf fission source were used to measure the deposit profile and its distribution along the pipe, the hydration (or H/U), and the total uranium mass. The measurements were performed with a source in an ionization chamber on one side of the pipe and detectors on the other. Scanning the pipe vertically and horizontally produced a spatial and time-dependent radiograph of the deposit in which transmitted gamma rays and neutrons were separated in time. The cross-correlation function between the source and the detector was measured with the Nuclear Weapons Identification System. After correcting for pipe effects, the deposit thickness was determined from the transmitted neutrons and H/U from the gamma rays. Results were consistent with a later intrusive observation of the shape and the color of the deposit; i.e., the deposit was annular and was on the top of the pipe at some locations, demonstrating the usefulness of this method for deposit characterization

  15. Energy transmission and power sources for mechanical circulatory support devices to achieve total implantability.

    Science.gov (United States)

    Wang, Jake X; Smith, Joshua R; Bonde, Pramod

    2014-04-01

    Left ventricular assist device therapy has radically improved congestive heart failure survival with smaller rotary pumps. The driveline used to power today's left ventricular assist devices, however, continues to be a source of infection, traumatic damage, and rehospitalization. Previous attempts to wirelessly power left ventricular assist devices using transcutaneous energy transfer systems have been limited by restrictions on separation distance and alignment between the transmit and receive coils. Resonant electrical energy transfer allows power delivery at larger distances without compromising safety and efficiency. This review covers the efforts to wirelessly power mechanical circulatory assist devices and the progress made in enhancing their energy sources. Copyright © 2014 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  16. Substantial population structure of Plasmodium vivax in Thailand facilitates identification of the sources of residual transmission.

    Directory of Open Access Journals (Sweden)

    Veerayuth Kittichai

    2017-10-01

    Full Text Available Plasmodium vivax transmission in Thailand has been substantially reduced over the past 10 years, yet it remains highly endemic along international borders. Understanding the genetic relationship of residual parasite populations can help track the origins of the parasites that are reintroduced into malaria-free regions within the country.A total of 127 P. vivax isolates were genotyped from two western provinces (Tak and Kanchanaburi and one eastern province (Ubon Ratchathani of Thailand using 10 microsatellite markers. Genetic diversity was high, but recent clonal expansion was detected in all three provinces. Substantial population structure and genetic differentiation of parasites among provinces suggest limited gene flow among these sites. There was no haplotype sharing among the three sites, and a reduced panel of four microsatellite markers was sufficient to assign the parasites to their provincial origins.Significant parasite genetic differentiation between provinces shows successful interruption of parasite spread within Thailand, but high diversity along international borders implies a substantial parasite population size in these regions. The provincial origin of P. vivax cases can be reliably determined by genotyping four microsatellite markers, which should be useful for monitoring parasite reintroduction after malaria elimination.

  17. Substantial population structure of Plasmodium vivax in Thailand facilitates identification of the sources of residual transmission.

    Science.gov (United States)

    Kittichai, Veerayuth; Koepfli, Cristian; Nguitragool, Wang; Sattabongkot, Jetsumon; Cui, Liwang

    2017-10-01

    Plasmodium vivax transmission in Thailand has been substantially reduced over the past 10 years, yet it remains highly endemic along international borders. Understanding the genetic relationship of residual parasite populations can help track the origins of the parasites that are reintroduced into malaria-free regions within the country. A total of 127 P. vivax isolates were genotyped from two western provinces (Tak and Kanchanaburi) and one eastern province (Ubon Ratchathani) of Thailand using 10 microsatellite markers. Genetic diversity was high, but recent clonal expansion was detected in all three provinces. Substantial population structure and genetic differentiation of parasites among provinces suggest limited gene flow among these sites. There was no haplotype sharing among the three sites, and a reduced panel of four microsatellite markers was sufficient to assign the parasites to their provincial origins. Significant parasite genetic differentiation between provinces shows successful interruption of parasite spread within Thailand, but high diversity along international borders implies a substantial parasite population size in these regions. The provincial origin of P. vivax cases can be reliably determined by genotyping four microsatellite markers, which should be useful for monitoring parasite reintroduction after malaria elimination.

  18. Progressive Image Transmission Based on Joint Source-Channel Decoding Using Adaptive Sum-Product Algorithm

    Directory of Open Access Journals (Sweden)

    David G. Daut

    2007-03-01

    Full Text Available A joint source-channel decoding method is designed to accelerate the iterative log-domain sum-product decoding procedure of LDPC codes as well as to improve the reconstructed image quality. Error resilience modes are used in the JPEG2000 source codec making it possible to provide useful source decoded information to the channel decoder. After each iteration, a tentative decoding is made and the channel decoded bits are then sent to the JPEG2000 decoder. The positions of bits belonging to error-free coding passes are then fed back to the channel decoder. The log-likelihood ratios (LLRs of these bits are then modified by a weighting factor for the next iteration. By observing the statistics of the decoding procedure, the weighting factor is designed as a function of the channel condition. Results show that the proposed joint decoding methods can greatly reduce the number of iterations, and thereby reduce the decoding delay considerably. At the same time, this method always outperforms the nonsource controlled decoding method by up to 3 dB in terms of PSNR.

  19. Progressive Image Transmission Based on Joint Source-Channel Decoding Using Adaptive Sum-Product Algorithm

    Directory of Open Access Journals (Sweden)

    Liu Weiliang

    2007-01-01

    Full Text Available A joint source-channel decoding method is designed to accelerate the iterative log-domain sum-product decoding procedure of LDPC codes as well as to improve the reconstructed image quality. Error resilience modes are used in the JPEG2000 source codec making it possible to provide useful source decoded information to the channel decoder. After each iteration, a tentative decoding is made and the channel decoded bits are then sent to the JPEG2000 decoder. The positions of bits belonging to error-free coding passes are then fed back to the channel decoder. The log-likelihood ratios (LLRs of these bits are then modified by a weighting factor for the next iteration. By observing the statistics of the decoding procedure, the weighting factor is designed as a function of the channel condition. Results show that the proposed joint decoding methods can greatly reduce the number of iterations, and thereby reduce the decoding delay considerably. At the same time, this method always outperforms the nonsource controlled decoding method by up to 3 dB in terms of PSNR.

  20. CRL X-ray tube

    International Nuclear Information System (INIS)

    Kolchevsky, N.N.; Petrov, P.V.

    2015-01-01

    A novel types of X-ray tubes with refractive lenses are proposed. CRL-R X-ray tube consists of Compound Refractive Lens- CRL and Reflection X-ray tube. CRL acts as X-ray window. CRL-T X-ray consists of CRL and Transmission X-ray tube. CRL acts as target for electron beam. CRL refractive lens acts as filter, collimator, waveguide and focusing lens. Properties and construction of the CRL X-ray tube are discussed. (authors)

  1. Realization of radiobiological in vitro cell experiments at conventional X-ray tubes and unconventional radiation sources

    International Nuclear Information System (INIS)

    Beyreuther, Elke

    2010-01-01

    More than hundred years after the discovery of X-rays different kinds of ionizing radiation are ubiquitous in medicine, applied to clinical diagnostics and cancer treatment as well. Irrespective of their nature, the widespread application of radiation implies its precise dosimetric characterization and detailed knowledge of the radiobiological effects induced in cancerous and normal tissue. Starting with in vitro cell irradiation experiments, which define basic parameters for the subsequent tissue and animal studies, the whole multi-stage process is completed by clinical trials that translate the results of fundamental research into clinical application. In this context, the present dissertation focuses on the establishment of radiobiological in vitro cell experiments at unconventional, but clinical relevant radiation qualities. In the first part of the present work the energy dependent biological effectiveness of photons was studied examining low-energy X-rays (≤ 50 keV), as used for mammography, and high-energy photons (≥ 20 MeV) as proposed for future radiotherapy. Cell irradiation experiments have been performed at conventional X-ray tubes providing low-energy photons and 200 kV reference radiation as well. In parallel, unconventional quasi-monochromatic channeling X-rays and high-energy bremsstrahlung available at the radiation source ELBE of the Forschungszentrum Dresden-Rossendorf were considered for radiobiological experimentation. For their precise dosimetric characterization dosimeters based on the thermally stimulated emission of exoelectrons and on radiochromic films were evaluated, whereas just the latter was found to be suitable for the determination of absolute doses and spatial dose distributions at cell position. Standard ionization chambers were deployed for the online control of cell irradiation experiments. Radiobiological effects were analyzed in human mammary epithelial cells on different subcellular levels revealing an increasing amount

  2. Realization of radiobiological in vitro cell experiments at conventional X-ray tubes and unconventional radiation sources

    Energy Technology Data Exchange (ETDEWEB)

    Beyreuther, Elke

    2010-09-10

    More than hundred years after the discovery of X-rays different kinds of ionizing radiation are ubiquitous in medicine, applied to clinical diagnostics and cancer treatment as well. Irrespective of their nature, the widespread application of radiation implies its precise dosimetric characterization and detailed knowledge of the radiobiological effects induced in cancerous and normal tissue. Starting with in vitro cell irradiation experiments, which define basic parameters for the subsequent tissue and animal studies, the whole multi-stage process is completed by clinical trials that translate the results of fundamental research into clinical application. In this context, the present dissertation focuses on the establishment of radiobiological in vitro cell experiments at unconventional, but clinical relevant radiation qualities. In the first part of the present work the energy dependent biological effectiveness of photons was studied examining low-energy X-rays (≤ 50 keV), as used for mammography, and high-energy photons (≥ 20 MeV) as proposed for future radiotherapy. Cell irradiation experiments have been performed at conventional X-ray tubes providing low-energy photons and 200 kV reference radiation as well. In parallel, unconventional quasi-monochromatic channeling X-rays and high-energy bremsstrahlung available at the radiation source ELBE of the Forschungszentrum Dresden-Rossendorf were considered for radiobiological experimentation. For their precise dosimetric characterization dosimeters based on the thermally stimulated emission of exoelectrons and on radiochromic films were evaluated, whereas just the latter was found to be suitable for the determination of absolute doses and spatial dose distributions at cell position. Standard ionization chambers were deployed for the online control of cell irradiation experiments. Radiobiological effects were analyzed in human mammary epithelial cells on different subcellular levels revealing an increasing amount

  3. Emission, transmission, deposition and environmental effects of ammonia from agricultural sources

    Energy Technology Data Exchange (ETDEWEB)

    Erisman, J.W. [ECN Clean Fossil Fuels, Petten (Netherlands); Dammgen, U. [Federal Agricultural Research Centre, Institute of Agroecology, Braunschweig (Germany)

    2005-05-01

    Air pollution in Europe has been regarded as a severe problem for several decades, the adverse effects being: the influence on the physical properties of the atmosphere itself, in particular its energy balance (global warming), and visibility; the influence on atmospheric chemistry (formation and destruction of both ground level and stratospheric ozone); the input of chemicals into terrestrial and aquatic ecosystems causing acidification and eutrophication leading to forest decline as well as changes in ecosystem structure and function; the effects on human health and welfare (the respiratory system). Since the sulfur dioxide problem seems to have been solved to a large extent in most countries in Western Europe, atmospheric nitrogen compounds are considered a major source of acidification. As most natural and near-natural ecosystems have developed with nitrogen as a limiting factor, increased inputs of reactive atmospheric nitrogen cause changes in their structure, function and nutrient dynamics. These effects are attributed to surplus nutrition (eutrophication) of the respective systems as the result of increased nitrogen inputs. At first it seemed logical to connect them with sources similar to those for sulfur (power plants, combustion engines, domestic heating); however, it soon became clear that reduced nitrogen (ammonia and ammonium in particulates) also plays a major role. This review is to collate the present state of knowledge with regard to ammonia emissions, its atmospheric transport and chemistry as well as its deposition and the resulting effects. It restricts itself to a description of the situation in Europe.

  4. Tube plug

    International Nuclear Information System (INIS)

    Zafred, P. R.

    1985-01-01

    The tube plug comprises a one piece mechanical plug having one open end and one closed end which is capable of being inserted in a heat exchange tube and internally expanded into contact with the inside surface of the heat exchange tube for preventing flow of a coolant through the heat exchange tube. The tube plug also comprises a groove extending around the outside circumference thereof which has an elastomeric material disposed in the groove for enhancing the seal between the tube plug and the tube

  5. TU-AB-BRC-07: Efficiency of An IAEA Phase-Space Source for a Low Energy X-Ray Tube Using Egs++

    Energy Technology Data Exchange (ETDEWEB)

    Watson, PGF; Renaud, MA; Seuntjens, J [McGill University, Montreal, Quebec (Canada)

    2016-06-15

    Purpose: To extend the capability of the EGSnrc C++ class library (egs++) to write and read IAEA phase-space files as a particle source, and to assess the relative efficiency gain in dose calculation using an IAEA phase-space source for modelling a miniature low energy x-ray source. Methods: We created a new ausgab object to score particles exiting a user-defined geometry and write them to an IAEA phase-space file. A new particle source was created to read from IAEA phase-space data. With these tools, a phase-space file was generated for particles exiting a miniature 50 kVp x-ray tube (The INTRABEAM System, Carl Zeiss). The phase-space source was validated by comparing calculated PDDs with a full electron source simulation of the INTRABEAM. The dose calculation efficiency gain of the phase-space source was determined relative to the full simulation. The efficiency gain as a function of i) depth in water, and ii) job parallelization was investigated. Results: The phase-space and electron source PDDs were found to agree to 0.5% RMS, comparable to statistical uncertainties. The use of a phase-space source for the INTRABEAM led to a relative efficiency gain of greater than 20 over the full electron source simulation, with an increase of up to a factor of 196. The efficiency gain was found to decrease with depth in water, due to the influence of scattering. Job parallelization (across 2 to 256 cores) was not found to have any detrimental effect on efficiency gain. Conclusion: A set of tools has been developed for writing and reading IAEA phase-space files, which can be used with any egs++ user code. For simulation of a low energy x-ray tube, the use of a phase-space source was found to increase the relative dose calculation efficiency by factor of up to 196. The authors acknowledge partial support by the CREATE Medical Physics Research Training Network grant of the Natural Sciences and Engineering Research Council (Grant No. 432290).

  6. Gastrostomy Tube (G-Tube)

    Science.gov (United States)

    ... any of these problems: a dislodged tube a blocked or clogged tube any signs of infection (including redness, swelling, or warmth at the tube site; discharge that's yellow, green, or foul-smelling; fever) excessive bleeding or drainage from the tube site severe abdominal pain lasting ...

  7. Radiation dose considerations by intra-individual Monte Carlo simulations in dual source spiral coronary computed tomography angiography with electrocardiogram-triggered tube current modulation and adaptive pitch

    Energy Technology Data Exchange (ETDEWEB)

    May, Matthias S.; Kuettner, Axel; Lell, Michael M.; Wuest, Wolfgang; Scharf, Michael; Uder, Michael [University of Erlangen, Department of Radiology, Erlangen (Germany); Deak, Paul; Kalender, Willi A. [University of Erlangen, Department of Medical Physics, Erlangen (Germany); Keller, Andrea K.; Haeberle, Lothar [University of Erlangen, Department of Medical Informatics, Biometry and Epidemiology, Erlangen (Germany); Achenbach, Stephan; Seltmann, Martin [University of Erlangen, Department of Cardiology, Erlangen (Germany)

    2012-03-15

    To evaluate radiation dose levels in patients undergoing spiral coronary computed tomography angiography (CTA) on a dual-source system in clinical routine. Coronary CTA was performed for 56 patients with electrocardiogram-triggered tube current modulation (TCM) and heart-rate (HR) dependent pitch adaptation. Individual Monte Carlo (MC) simulations were performed for dose assessment. Retrospective simulations with constant tube current (CTC) served as reference. Lung tissue was segmented and used for organ and effective dose (ED) calculation. Estimates for mean relative ED was 7.1 {+-} 2.1 mSv/100 mAs for TCM and 12.5 {+-} 5.3 mSv/100 mAs for CTC (P < 0.001). Relative dose reduction at low HR ({<=}60 bpm) was highest (49 {+-} 5%) compared to intermediate (60-70 bpm, 33 {+-} 12%) and high HR (>70 bpm, 29 {+-} 12%). However lowest ED is achieved at high HR (5.2 {+-} 1.5 mSv/100 mAs), compared with intermediate (6.7 {+-} 1.6 mSv/100 mAs) and low (8.3 {+-} 2.1 mSv/100 mAs) HR when automated pitch adaptation is applied. Radiation dose savings up to 52% are achievable by TCM at low and regular HR. However lowest ED is attained at high HR by pitch adaptation despite inferior radiation dose reduction by TCM. circle Monte Carlo simulations allow for individual radiation dose calculations. (orig.)

  8. Radiation dose considerations by intra-individual Monte Carlo simulations in dual source spiral coronary computed tomography angiography with electrocardiogram-triggered tube current modulation and adaptive pitch

    International Nuclear Information System (INIS)

    May, Matthias S.; Kuettner, Axel; Lell, Michael M.; Wuest, Wolfgang; Scharf, Michael; Uder, Michael; Deak, Paul; Kalender, Willi A.; Keller, Andrea K.; Haeberle, Lothar; Achenbach, Stephan; Seltmann, Martin

    2012-01-01

    To evaluate radiation dose levels in patients undergoing spiral coronary computed tomography angiography (CTA) on a dual-source system in clinical routine. Coronary CTA was performed for 56 patients with electrocardiogram-triggered tube current modulation (TCM) and heart-rate (HR) dependent pitch adaptation. Individual Monte Carlo (MC) simulations were performed for dose assessment. Retrospective simulations with constant tube current (CTC) served as reference. Lung tissue was segmented and used for organ and effective dose (ED) calculation. Estimates for mean relative ED was 7.1 ± 2.1 mSv/100 mAs for TCM and 12.5 ± 5.3 mSv/100 mAs for CTC (P 70 bpm, 29 ± 12%). However lowest ED is achieved at high HR (5.2 ± 1.5 mSv/100 mAs), compared with intermediate (6.7 ± 1.6 mSv/100 mAs) and low (8.3 ± 2.1 mSv/100 mAs) HR when automated pitch adaptation is applied. Radiation dose savings up to 52% are achievable by TCM at low and regular HR. However lowest ED is attained at high HR by pitch adaptation despite inferior radiation dose reduction by TCM. circle Monte Carlo simulations allow for individual radiation dose calculations. (orig.)

  9. RESONANCE CONTROL FOR THE COUPLED CAVITY LINAC AND DRIFT TUBE LINAC STRUCTURES OF THE SPALLATION NEUTRON SOURCE LINAC USING A CLOSED-LOOP WATER COOLING SYSTEM

    International Nuclear Information System (INIS)

    Bernardin, J.D.; Brown, R.L.

    2001-01-01

    The Spallation Neutron Source (SNS) is a facility being designed for scientific and industrial research and development. SNS will generate and use neutrons as a diagnostic tool for medical purposes, material science, etc. The neutrons will be produced by bombarding a heavy metal target with a high-energy beam of protons, generated and accelerated with a linear particle accelerator, or linac. The low energy end of the linac consists of two room temperature copper structures, the drift tube linac (DTL), and the coupled cavity linac (CCL). Both of these accelerating structures use large amounts of electrical energy to accelerate the protons to an energy of 185 MeV. Approximately 60-80% of the electrical energy is dissipated in the copper structure and must be removed. This is done using specifically designed water cooling passages within the linac's copper structure. Cooling water is supplied to these cooling passages by specially designed resonance control and water cooling systems

  10. Elemental analysis of the ancient bronze coins by x-ray fluorescence technique using simultaneously radioisotope source and x-ray tube

    International Nuclear Information System (INIS)

    Nguyen The Quynh; Truong Thi An; Tran Duc Thiep; Nguyen Dinh Chien; Dao Tran Cao; Nguyen Quang Liem

    2004-01-01

    The results on elemental analysis of the Vietnamese ancient bronze coins during the time of the Nguyen dynasty (19th century) are presented. The samples were provided by the vietnam National Historical Museum and the elemental analysis was performed on the home-made model EDS-XT-99-01 X-ray fluorescence spectrometer in the Institute of Materials Science, NCST of Vietnam. The samples exited simultaneously by radioisotope source and X-ray tube. The analytical results show the similarity in the elemental composition of the coins issued by different kings of the Nguyen dynasty, but there is the difference in the concentration of the used elements. Another interesting point is that all the coins have zinc (Zn) in their composition, which shows clearly the influence of the occidental metallurgical technology on the money-making technique in Vietnam during the 19th century. (author)

  11. Reduced harm or another gateway to smoking? source, message, and information characteristics of E-cigarette videos on YouTube.

    Science.gov (United States)

    Paek, Hye-Jin; Kim, Sookyong; Hove, Thomas; Huh, Jung Yoon

    2014-01-01

    E-cigarettes are widely promoted on the Internet, but little is known about what kinds of information about them are available online. This study examines message, source, and health information characteristics of e-cigarette videos on the popular online video-sharing platform YouTube. A content analysis of 365 e-cigarette videos indicates that 85% of the videos were sponsored by marketers. These videos highlight e-cigarettes' economic and social benefits, featuring a low level of fear appeal and negative message valence and a high level of marketing information about e-cigarette products. They also convey certain health claims that have been proscribed by the U.S. Food and Drug Administration, the prevalence of which warrants ongoing monitoring and regulatory guidelines for online e-cigarette marketing.

  12. Dual-Source Dual-Energy CT Angiography of the Supra-Aortic Arteries with Tin Filter: Impact of Tube Voltage Selection.

    Science.gov (United States)

    Korn, Andreas; Bender, Benjamin; Schabel, Christoph; Bongers, Malte; Ernemann, Ulrike; Claussen, Claus; Thomas, Christoph

    2015-06-01

    Automatic bone and plaque subtraction (BPS) in computed tomographic angiographic (CTA) examinations using dual-energy CT (DECT) remains challenging because of beam-hardening artifacts in the shoulder region and close proximity of the internal carotid artery to the base of the skull. The selection of the tube voltage combination in dual-source CT influences the spectral separation and the susceptibility for artifacts. The purpose of this study was to assess which tube voltage combination leads to an optimal image quality of head and neck DECT angiograms after bone subtraction. Fifty-one patients received tin-filter-enhanced DECT angiograms of the supra-aortic arteries using two voltage protocols: 24 patients were studied using 80/Sn140 kV and 27 using a 100/Sn140 kV protocol, both protocols with an additional tin filter. A commercially available DE-CTA BPS algorithm was used. Artificial vessel erosions in BPS maximum intensity projections (four-level Likert scale with CTA source data as reference) and vessel signal-to-noise ratio (SNR) were assessed in the level of the shoulders and the base of the skull in each patient and compared. At the level of the shoulder, 100/Sn140 kV achieved higher SNR (23.4 ± 6.4 at 80/Sn140 kV vs. 35.1 ± 11.8 at 100/Sn140 kV; P supra-aortic arteries than the 80/Sn140 kV protocol. Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.

  13. Three-dimensional balanced steady state free precession myocardial perfusion cardiovascular magnetic resonance at 3T using dual-source parallel RF transmission: initial experience.

    Science.gov (United States)

    Jogiya, Roy; Schuster, Andreas; Zaman, Arshad; Motwani, Manish; Kouwenhoven, Marc; Nagel, Eike; Kozerke, Sebastian; Plein, Sven

    2014-11-28

    The purpose of this study was to establish the feasibility of three-dimensional (3D) balanced steady-state-free-precession (bSSFP) myocardial perfusion cardiovascular magnetic resonance (CMR) at 3T using local RF shimming with dual-source RF transmission, and to compare it with spoiled gradient echo (TGRE) acquisition. Dynamic contrast-enhanced 3D bSSFP perfusion imaging was performed on a 3T MRI scanner equipped with dual-source RF transmission technology. Images were reconstructed using k-space and time broad-use linear acquisition speed-up technique (k-t BLAST) and compartment based principle component analysis (k-t PCA). In phantoms and volunteers, local RF shimming with dual source RF transmission significantly improved B1 field homogeneity compared with single source transmission (P=0.01). 3D bSSFP showed improved signal-to-noise, contrast-to-noise and signal homogeneity compared with 3D TGRE (29.8 vs 26.9, P=0.045; 23.2 vs 21.6, P=0.049; 14.9% vs 12.4%, p=0.002, respectively). Image quality was similar between bSSFP and TGRE but there were more dark rim artefacts with bSSFP. k-t PCA reconstruction reduced artefacts for both sequences compared with k-t BLAST. In a subset of five patients, both methods correctly identified those with coronary artery disease. Three-dimensional bSSFP myocardial perfusion CMR using local RF shimming with dual source parallel RF transmission at 3T is feasible and improves signal characteristics compared with TGRE. Image artefact remains an important limitation of bSSFP imaging at 3T but can be reduced with k-t PCA.

  14. Prospectively ECG-triggered high-pitch coronary angiography with third-generation dual-source CT at 70 kVp tube voltage: feasibility, image quality, radiation dose, and effect of iterative reconstruction.

    Science.gov (United States)

    Hell, Michaela M; Bittner, Daniel; Schuhbaeck, Annika; Muschiol, Gerd; Brand, Michael; Lell, Michael; Uder, Michael; Achenbach, Stephan; Marwan, Mohamed

    2014-01-01

    Low tube voltage reduces radiation exposure in coronary CT angiography (CTA). Using 70 kVp tube potential has so far not been possible because CT systems were unable to provide sufficiently high tube current with low voltage. We evaluated feasibility, image quality (IQ), and radiation dose of coronary CTA using a third-generation dual-source CT system capable of producing 450 mAs tube current at 70 kVp tube voltage. Coronary CTA was performed in 26 consecutive patients with suspected coronary artery disease, selected for body weight Image noise was lower in IR vs FBP (60 ± 10 HU vs 74 ± 8 HU; P < .001). In patients <100 kg and with a regular heart rate <60 beats/min, third-generation dual-source CT using high-pitch spiral acquisition and 70 kVp tube voltage is feasible and provides both robust IQ and very low radiation exposure. Copyright © 2014 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

  15. The impact of dual-source parallel radiofrequency transmission with patient-adaptive shimming on the cardiac magnetic resonance in children at 3.0 T.

    Science.gov (United States)

    Wang, Haipeng; Qiu, Liyun; Wang, Guangbin; Gao, Fei; Jia, Haipeng; Zhao, Junyu; Chen, Weibo; Wang, Cuiyan; Zhao, Bin

    2017-06-01

    The cardiac magnetic resonance (CMR) of children at 3.0 T presents a unique set of technical challenges because of their small cardiac anatomical structures, fast heart rates, and the limited ability to keep motionless and hold breathe, which could cause problems associated with field inhomogeneity and degrade the image quality. The aim of our study was to evaluate the effect of dual-source parallel radiofrequency (RF) transmission on the B1 homogeneity and image quality in children with CMR at 3.0 T. The study was approved by the institutional ethics committee and written informed consent was obtained. A total of 30 free-breathing children and 30 breath-hold children performed CMR examinations with dual-source and single-source RF transmission. The B1 homogeneity, contrast ratio (CR) of cine images, and off-resonance artifacts in cine images between dual-source and single-source RF transmission were assessed in free-breathing and breath-hold groups, respectively. In both free-breathing and breath-hold groups, higher mean percentage of flip angle (free-breathing group: 104.2 ± 4.6 vs 95.5 ± 6.3, P 3.0 T. This technology could be taken into account in CMR for children with cardiac diseases.

  16. Quantifying Transmission.

    Science.gov (United States)

    Woolhouse, Mark

    2017-07-01

    Transmissibility is the defining characteristic of infectious diseases. Quantifying transmission matters for understanding infectious disease epidemiology and designing evidence-based disease control programs. Tracing individual transmission events can be achieved by epidemiological investigation coupled with pathogen typing or genome sequencing. Individual infectiousness can be estimated by measuring pathogen loads, but few studies have directly estimated the ability of infected hosts to transmit to uninfected hosts. Individuals' opportunities to transmit infection are dependent on behavioral and other risk factors relevant given the transmission route of the pathogen concerned. Transmission at the population level can be quantified through knowledge of risk factors in the population or phylogeographic analysis of pathogen sequence data. Mathematical model-based approaches require estimation of the per capita transmission rate and basic reproduction number, obtained by fitting models to case data and/or analysis of pathogen sequence data. Heterogeneities in infectiousness, contact behavior, and susceptibility can have substantial effects on the epidemiology of an infectious disease, so estimates of only mean values may be insufficient. For some pathogens, super-shedders (infected individuals who are highly infectious) and super-spreaders (individuals with more opportunities to transmit infection) may be important. Future work on quantifying transmission should involve integrated analyses of multiple data sources.

  17. Influence of trigger type, tube voltage and heart rate on calcified plaque imaging in dual source cardiac computed tomography: phantom study

    International Nuclear Information System (INIS)

    Penzkofer, Tobias; Donandt, Eva; Isfort, Peter; Allmendinger, Thomas; Kuhl, Christiane K; Mahnken, Andreas H; Bruners, Philipp

    2014-01-01

    To investigate the impact of high pitch cardiac CT vs. retrospective ECG gated CT on the quantification of calcified vessel stenoses, with assessment of the influence of tube voltage, reconstruction kernel and heart rate. A 4D cardiac movement phantom equipped with three different plaque phantoms (12.5%, 25% and 50% stenosis at different calcification levels), was scanned with a 128-row dual source CT scanner, applying different trigger types (gated vs. prospectively triggered high pitch), tube voltages (100-120 kV) and heart rates (50–90 beats per minute, bpm). Images were reconstructed using different standard (B26f, B46f, B70f) and iterative (I26f, I70f) convolution kernels. Absolute and relative plaque sizes were measured and statistically compared. Radiation dose associated with the different methods (gated vs. high pitch, 100 kV vs. 120 kV) were compared. Compared to the known diameters of the phantom plaques and vessels both CT-examination techniques overestimated the degrees of stenoses. Using the high pitch CT-protocol plaques appeared larger (0.09 ± 0.31 mm, 2 ± 8 percent points, PP) in comparison to the ECG-gated CT-scans. Reducing tube voltage had a similar effect, resulting in higher grading of the same stenoses by 3 ± 8 PP. In turn, sharper convolution kernels lead to a lower grading of stenoses (differences of up to 5%). Pairwise comparison of B26f and I26f, B46f and B70f, and B70f and I70f showed differences of 0–1 ± 6–8 PP of the plaque depiction. Motion artifacts were present only at 90 bpm high pitch experiments. High-pitch protocols were associated with significantly lower radiation doses compared with the ECG-gated protocols (258.0 mGy vs. 2829.8 mGy CTDI vol , p ≤ 0.0001). Prospectively triggered high-pitch cardiac CT led to an overestimation of plaque diameter and degree of stenoses in a coronary phantom. This overestimation is only slight and probably negligible in a clinical situation. Even at higher heart rates high pitch CT

  18. English-language videos on YouTube as a source of information on self-administer subcutaneous anti-tumour necrosis factor agent injections.

    Science.gov (United States)

    Tolu, Sena; Yurdakul, Ozan Volkan; Basaran, Betul; Rezvani, Aylin

    2018-05-14

    The aim of this study was to evaluate the reliability, content, and quality of videos for patients available on YouTube for learning how to self-administer subcutaneous anti-tumour necrosis factor (TNF) injections. We searched for the terms Humira injection, Enbrel injection, Simponi injection, and Cimzia injection. Videos were categorised as useful information, misleading information, useful patient opinion, and misleading patient opinion by two physicians. Videos were rated for quality on a 5-point global quality scale (GQS; 1 = poor quality, 5 = excellent quality) and reliability and content using the 5-point DISCERN scale (higher scores represent greater reliability and more comprehensive videos). Of the 142 English videos, 24 (16.9%) videos were classified as useful information, 6 (4.2%) as misleading information, 47 (33.1%) as useful patient opinion, and 65 (45.8%) as misleading patient opinion. Useful videos were the most comprehensive and had the highest reliability and quality scores. The useful information and useful patient opinion videos had the highest numbers of views per day (median 8.32, IQR: 3.40-14.28 and 5.46, IQR: 3.06-14.44), as compared with 2.32, IQR: 1.63-6.26 for misleading information videos and 2.15, IQR: 1.17-7.43 for misleading patient opinion videos (p = 0.001). Almost all (91.5%) misleading videos were uploaded by individual users. There are a substantial number of English-language YouTube videos, with high quality, and rich content and reliability that can be sources of information on proper technique of anti-TNF self-injections. Physicians should direct patients to the reliable resources of information and educate them in online resource assessment, thereby improving treatment outcomes.

  19. X-ray tube

    International Nuclear Information System (INIS)

    Webley, R.S.

    1975-01-01

    The object of the invention described is to provide an X-ray tube providing a scanned X-ray output which does not require a scanned electron beam. This is obtained by an X-ray tube including an anode which is rotatable about an axis, and a source of a beam of energy, for example an electron beam, arranged to impinge on a surface of the anode to generate X-radiation substantially at the region of incidence on the anode surface. The anode is rotatable about the axis to move the region of incidence over the surface. The anode is so shaped that the rotation causes the region of incidence to move in a predetermined manner relative to fixed parts of the tube so that the generated X-radiation is scanned in a predetermined manner relative to the tube. (UK)

  20. Sealed ion accelerator tubes (survey)

    International Nuclear Information System (INIS)

    Voitsik, L.R.

    1985-01-01

    The first publications on developing commercial models of small-scale sealed accelerator tubes in which neutrons are generated appeared in the foreign press in 1954 to 1957; they were very brief and were advertising-oriented. The tubes were designed for neutron logging of oil wells instead of ampule neutron sources (Po + Be, Ra + Be). Later, instruments of this type began to be called neutron tubes from the resulting neutron radiation that they gave off. In Soviet Union a neutron tube was developed in 1958 in connection with the development of the pulsed neutron-neutron method of studying the geological profile of oil wells. At that time the tube developed was intended, in the view of its inventors, to replace standard isotope sources with constant neutron yield. A fairly detailed survey of neutron tubes was made in the studies. 8 refs., 8 figs

  1. Use of Zircaloy 4 material for the pressure vessels of hot and cold neutron sources and beam tubes for research reactors

    International Nuclear Information System (INIS)

    Scheuer, A.; Gutsmiedl, E.

    1999-01-01

    The material Zircaloy 4 can be used for the pressure retaining walls for the cold and hot neutron sources and beam tubes. For the research reactor FRM-II of the Technical University Munich, Germany, the material Zircaloy 4 were chosen for the vessels of the cold and hot neutron source and for the beam tube No. 6. The sheets and forgings of Zircaloy 4 were examined in the temperature range between -256 deg. C and 250 deg. C. The thickness of the sheets are 3, 4, 5 and 10 mm, the maximum diameter of the forgings was 560 mm. This great forging diameters are not be treated in the ASTM rule B 351 for nuclear material, so a special approval with independent experts was necessary. The requirements for the material examinations were specified in a material specification and material test sheets which based on the ASTM rules B 351 and B 352 with additional restriction and additional requirements of the basic safety concept for nuclear power plants in Germany, which was take into consideration in the nuclear licensing procedure. Charpy-V samples were carried out in the temperature range between -256 deg. C and 150 deg. C to get more information on the ductile behaviour of the Zircaloy 4. The results of the sheet examination confirm the requirements of the specifications, the results of the forging examination in the tangential testing direction are lower than specified and expected for the tensile strength. The axial and transverse values confirm the specification requirements. For the strength calculation of the pressure retaining wall a reduced material value for the forgings has to take into consideration. The material behaviour of Zircaloy 4 under irradiation up to a fluence of ∼ 1x10 22 n/cm 2 was investigated. The loss of ductility was determined. As an additional criteria the variation of the fracture toughness was studies. Fracture mechanic calculations of the material were carried out in the licensing procedure with the focus to fulfill the leak before rupture

  2. Use of Zircaloy 4 material for the pressure vessels of hot and cold neutron sources and beam tubes for research reactors

    International Nuclear Information System (INIS)

    Gutsmiedl, Erwin

    2001-01-01

    The material Zircaloy 4 can be used for the pressure retaining walls for the cold and hot neutron sources and beam tubes. For the research reactor FRM-II of the Technical University Munich, Germany, the material Zircaloy 4 were chosen for the vessels of the cold and hot neutron source and for the beam tube No. 6. The sheets and forgings of Zircaloy 4 were examined in the temperature range between -256degC and 250degC. The thickness of the sheets are 3, 4, 5 and 10 mm, the maximum diameter of the forgings was 560 mm. This great forging diameters are not be treated in the ASTM rule B 351 for nuclear material, so a special approval with independent experts was necessary. The requirements for the material examinations were specified in a material specification and material test sheets which based on the ASTM rules B 351 and B 352 with additional restriction and additional requirements of the basic safety concept for nuclear power plants in Germany, which was taken into consideration in the nuclear licensing procedure. Charpy-V samples were carried out in the temperature range between -256degC and 150degC to get more information on the ductile behaviour of the Zircaloy 4. The results of the sheet examination confirm the requirements of the specifications, the results of the forging examination in the tangential testing direction are lower than specified and expected for the tensile strength. The axial and transverse values confirm the specification requirements. For the strength calculation of the pressure retaining wall a reduced material value for the forgings has to taken into consideration. The material behaviour of Zircaloy 4 under irradiation up to a fluence of ∼1·10 22 n/cm 2 was investigated. The loss of ductility was determined. As an additional criteria the variation of the fracture toughness was studies. Fracture mechanic calculations of the material were carried out in the licensing procedure with the focus to fulfill the leak before rupture criteria of

  3. Optimization of transmission-scan time for the FixER method: a MR-based PET attenuation correction with a weak fixed-position external radiation source

    Energy Technology Data Exchange (ETDEWEB)

    Kawaguchi, Hiroshi; Hirano, Yoshiyuki; Kershaw, Jeff; Yoshida, Eiji [Molecular Imaging Center, National Institute of Radiological Sciences, Chiba (Japan); Shiraishi, Takahiro [Molecular Imaging Center, National Institute of Radiological Sciences, Chiba (Japan); Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan); Suga, Mikio [Molecular Imaging Center, National Institute of Radiological Sciences, Chiba (Japan); Center for Frontier Medical Engineering, Chiba University (Japan); Obata, Takayuki [Molecular Imaging Center, National Institute of Radiological Sciences, Chiba (Japan); Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan); Ito, Hiroshi; Yamaya, Taiga [Molecular Imaging Center, National Institute of Radiological Sciences, Chiba (Japan)

    2014-07-29

    In recent work, we proposed an MRI-based attenuation-coefficient (μ-value) estimation method that uses a weak fixed-position external radiation source to construct an attenuation map for PET/MRI. In this presentation we refer to this method as FixER, and perform a series of simulations to investigate the duration of the transmission scan required to accurately estimate μ-values.

  4. Optimization of transmission-scan time for the FixER method: a MR-based PET attenuation correction with a weak fixed-position external radiation source

    International Nuclear Information System (INIS)

    Kawaguchi, Hiroshi; Hirano, Yoshiyuki; Kershaw, Jeff; Yoshida, Eiji; Shiraishi, Takahiro; Suga, Mikio; Obata, Takayuki; Ito, Hiroshi; Yamaya, Taiga

    2014-01-01

    In recent work, we proposed an MRI-based attenuation-coefficient (μ-value) estimation method that uses a weak fixed-position external radiation source to construct an attenuation map for PET/MRI. In this presentation we refer to this method as FixER, and perform a series of simulations to investigate the duration of the transmission scan required to accurately estimate μ-values.

  5. Cardiac MOLLI T1 mapping at 3.0 T: comparison of patient-adaptive dual-source RF and conventional RF transmission.

    Science.gov (United States)

    Rasper, Michael; Nadjiri, Jonathan; Sträter, Alexandra S; Settles, Marcus; Laugwitz, Karl-Ludwig; Rummeny, Ernst J; Huber, Armin M

    2017-06-01

    To prospectively compare image quality and myocardial T 1 relaxation times of modified Look-Locker inversion recovery (MOLLI) imaging at 3.0 T (T) acquired with patient-adaptive dual-source (DS) and conventional single-source (SS) radiofrequency (RF) transmission. Pre- and post-contrast MOLLI T 1 mapping using SS and DS was acquired in 27 patients. Patient wise and segment wise analysis of T 1 times was performed. The correlation of DS MOLLI measurements with a reference spin echo sequence was analysed in phantom experiments. DS MOLLI imaging reduced T 1 standard deviation in 14 out of 16 myocardial segments (87.5%). Significant reduction of T 1 variance could be obtained in 7 segments (43.8%). DS significantly reduced myocardial T 1 variance in 16 out of 25 patients (64.0%). With conventional RF transmission, dielectric shading artefacts occurred in six patients causing diagnostic uncertainty. No according artefacts were found on DS images. DS image findings were in accordance with conventional T 1 mapping and late gadolinium enhancement (LGE) imaging. Phantom experiments demonstrated good correlation of myocardial T 1 time between DS MOLLI and spin echo imaging. Dual-source RF transmission enhances myocardial T 1 homogeneity in MOLLI imaging at 3.0 T. The reduction of signal inhomogeneities and artefacts due to dielectric shading is likely to enhance diagnostic confidence.

  6. Feeding Tubes

    Science.gov (United States)

    ... feeding therapies have been exhausted. Please review product brand and method of placement carefully with your physician ... Total Parenteral Nutrition. Resources: Oley Foundation Feeding Tube Awareness Foundation Children’s Medical Nutrition Alliance APFED’s Educational Webinar ...

  7. Source coding for transmission of reconstructed dynamic geometry: a rate-distortion-complexity analysis of different approaches

    NARCIS (Netherlands)

    R.N. Mekuria (Rufael); P.S. Cesar Garcia (Pablo Santiago); D.C.A. Bulterman (Dick)

    2014-01-01

    htmlabstractLive 3D reconstruction of a human as a 3D mesh with commodity electronics is becoming a reality. Immersive applications (i.e. cloud gaming, tele-presence) benefit from effective transmission of such content over a bandwidth limited link. In this paper we outline different approaches for

  8. Streak tube development

    International Nuclear Information System (INIS)

    Hinrichs, C.K.; Estrella, R.M.

    1979-01-01

    A research program for the development of a high-speed, high-resolution streak image tube is described. This is one task in the development of a streak camera system with digital electronic readout, whose primary application is for diagnostics in underground nuclear testing. This program is concerned with the development of a high-resolution streak image tube compatible with x-ray input and electronic digital output. The tube must be capable of time resolution down to 100 psec and spatial resolution to provide greater than 1000 resolution elements across the cathode (much greater than presently available). Another objective is to develop the capability to make design changes in tube configurations to meet different experimental requirements. A demountable prototype streak tube was constructed, mounted on an optical bench, and placed in a vacuum system. Initial measurements of the tube resolution with an undeflected image show a resolution of 32 line pairs per millimeter over a cathode diameter of one inch, which is consistent with the predictions of the computer simulations. With the initial set of unoptmized deflection plates, the resolution pattern appeared to remain unchanged for static deflections of +- 1/2-inch, a total streak length of one inch, also consistent with the computer simulations. A passively mode-locked frequency-doubled dye laser is being developed as an ultraviolet pulsed light source to measure dynamic tube resolution during streaking. A sweep circuit to provide the deflection voltage in the prototype tube has been designed and constructed and provides a relatively linear ramp voltage with ramp durations adjustable between 10 and 1000 nsec

  9. Steam generator tube extraction

    International Nuclear Information System (INIS)

    Delorme, H.

    1985-05-01

    To enable tube examination on steam generators in service, Framatome has now developed a process for removing sections of steam generator tubes. Tube sections can be removed without being damaged for treating the tube section expanded in the tube sheet

  10. Detecting Intracranial Hemorrhage Using Automatic Tube Current Modulation With Advanced Modeled Iterative Reconstruction in Unenhanced Head Single- and Dual-Energy Dual-Source CT.

    Science.gov (United States)

    Scholtz, Jan-Erik; Wichmann, Julian L; Bennett, Dennis W; Leithner, Doris; Bauer, Ralf W; Vogl, Thomas J; Bodelle, Boris

    2017-05-01

    The purpose of our study was to determine diagnostic accuracy, image quality, and radiation dose of low-dose single- and dual-energy unenhanced third-generation dual-source head CT for detection of intracranial hemorrhage (ICH). A total of 123 patients with suspected ICH were examined using a dual-source 192-MDCT scanner. Standard-dose 120-kVp single-energy CT (SECT; n = 36) and 80-kVp and 150-kVp dual-energy CT (DECT; n = 30) images were compared with low-dose SECT (n = 32) and DECT (n = 25) images obtained using automated tube current modulation (ATCM). Advanced modeled iterative reconstruction (ADMIRE) was used for all protocols. Detection of ICH was performed by three readers who were blinded to the image acquisition parameters of each image series. Image quality was assessed both quantitatively and qualitatively. Interobserver agreement was calculated using the Fleiss kappa. Radiation dose was measured as dose-length product (DLP). Detection of ICH was excellent (sensitivity, 94.9-100%; specificity, 94.7-100%) in all protocols (p = 1.00) with perfect interobserver agreement (0.83-0.96). Qualitative ratings showed significantly better ratings for both standard-dose protocols regarding gray matter-to-white matter contrast (p ≤ 0.014), whereas highest gray matter-to-white matter contrast-to-noise ratio was observed with low-dose DECT images (p ≥ 0.057). The lowest posterior fossa artifact index was measured for standard-dose DECT, which showed significantly lower values compared with low-dose protocols (p ≤ 0.034). Delineation of ventricular margins and sharpness of subarachnoidal spaces were rated excellent in all protocols (p ≥ 0.096). Low-dose techniques lowered radiation dose by 26% for SECT images (DLP, 575.0 ± 72.3 mGy · cm vs 771.5 ± 146.8 mGy · cm; p dual-source CT while allowing significant radiation dose reduction.

  11. Identification of the excitation source of the pressure vessel vibration in a Soviet built WWER PWR with signal transmission path analysis

    International Nuclear Information System (INIS)

    Antonopoulos-Domis, M.; Mourtzanos, K.; Por, G.

    1996-01-01

    Signal transmission path analysis via multivariate auto-regressive modelling was applied at signals recorded at a WWER power reactor (Paks reactor, Hungary). The core is equipped with strings of self-powered neutron detectors (SPNDs). Each string has seven SPNDs. The signals were high pass filtered with cut-off at 0.03 Hz and low pass-filtered with cut-off at 25 Hz. The analysis suggests that the source of excitation of all signals at 25 Hz is due to main coolant pump vibration. It was confirmed that there is vibration of main coolant pumps at this frequency due to a bearing problem. Signal transmission path analysis also suggests direct paths from outlet coolant to inlet coolant pressure and in-core neutron detectors at the upper part of the core. (author)

  12. Zoonotic disease in a peripheral population: persistence and transmission of Leishmania major in a putative sink-source system in the Negev Highlands, Israel.

    Science.gov (United States)

    Berger, Ruti; Wasserberg, Gideon; Warburg, Alon; Orshan, Laor; Kotler, Burt P

    2014-08-01

    Populations at the edge of their geographic distributions are referred to as peripheral populations. Very little attention has been given to this topic in the context of persistence of infectious disease in natural populations. In this study, we examined this question using zoonotic cutaneous leishmaniasis (ZCL) caused by Leishmania major in the Negev Desert of Israel as a model system. Here, we suggest that the regional persistence of Phlebotomus papatasi populations and L. major transmission in the Sede Boqer region could be explained through processes akin to sink-source and/or mainland-island metapopulation dynamics. Given its potentially enzootically superior ecological conditions, we hypothesize that the Zin Valley ecotope constitutes the "mainland" or the "source" patch for the Sede Boqer area where L. major transmission is persistent and resistant to local extinctions (die-outs) whereas the local sand fly populations on the Zin Plateau ("island patch" or "sink patch") are more prone to local extinctions. Between 2007 and 2008, we trapped sand flies and sand rats in the two areas and compared sand fly abundance and L. major infection prevalence in both. In both 2007 and 2008, sand fly abundance was high and continuous in the Zin Wadi but low and discontinuous in the Zin Plateau. Infection prevalence of sand rats was significantly higher in the Wadi (13%) compared with the Zin Plateau (3%). Minimum infection rate in sand flies did not differ significantly between the two areas. Overall, our results are consistent with the premise that the Zin Valley population is relatively robust in terms of L. major transmission, whereas transmission is potentially more tenuous in the plateau. Understanding the biotic and abiotic processes enabling the persistence of L. major and other vector-borne diseases in peripheral disease foci is important for predicting the effect of anthropogenic land use and climate change.

  13. SG tube identification

    International Nuclear Information System (INIS)

    Hoogstraten, P. van

    1994-01-01

    A ''Tracker'' system is described which is designed to identify any tube in a reactor steam generator quickly and safely. Occupational radiation doses to maintenance workers are reduced by using a Tracker and emergency down times are shortened. The system employs a television camera and light source in a stainless steel box with a large window. Both the camera and spotlight can be panned and tilted to reach any point on the tubesheet and are remotely controlled. An operator at a safe working distance can identify any tube visible on a real time video by comparison with the tubesheet pattern stored earlier in the computer memory. The identified tube can then be spotlighted and dealt with quickly by a maintenance worker inside the channel head. (UK)

  14. Transmission line matching simulation for 350 MHz RF driver for 400 KeV (deuterium) RFQ based 14 MeV neutron source

    International Nuclear Information System (INIS)

    Sharma, Sonal; Pande, Manjiri; Handu, V.K.

    2009-01-01

    A 60 KW, 350 MHz tetrode based high power RF system is being developed for 400 KeV RFQ based 14 MeV neutron generator in Bhabha Atomic Research Centre to study physics of coupled neutron sources and subcritical assembly. This RF system requires a 2.5 kW RF driver which is being designed by using tetrode TH-393. At such high frequency i.e. 350 MHz, lumped components are not practically useful due to radiation losses. Therefore, techniques such as coaxial line with stub tuning are preferred, which minimizes these losses. Simulation of two such stub tuning based matched coaxial lines at the input and output of the tube has been done by using CST studio. CST STUDIO is a special tool for the 3D EM simulation of high frequency components

  15. CW 50W/M2 = 10.9 diode laser source by spectral beam combining based on a transmission grating.

    Science.gov (United States)

    Zhang, Jun; Peng, Hangyu; Fu, Xihong; Liu, Yun; Qin, Li; Miao, Guoqing; Wang, Lijun

    2013-02-11

    An external cavity structure based on the -1st transmission grating is introduced to spectral beam combining a 970 nm diode laser bar. A CW output power of 50.8 W, an electro-optical conversion efficiency of 45%, a spectral beam combining efficiency of 90.2% and a holistic M(2) value of 10.9 are achieved. This shows a way for a diode laser source with several KW power and diffraction-limited beam quality at the same time.

  16. Ear Tubes

    Science.gov (United States)

    ... of the ear drum or eustachian tube, Down Syndrome, cleft palate, and barotrauma (injury to the middle ear caused by a reduction of air pressure, ... specialist) may be warranted if you or your child has experienced repeated ... fluid in the middle ear, barotrauma, or have an anatomic abnormality that ...

  17. Acute hepatitis B outbreaks in 2 skilled nursing facilities and possible sources of transmission: North Carolina, 2009-2010.

    Science.gov (United States)

    Seña, Arlene C; Moorman, Anne; Njord, Levi; Williams, Roxanne E; Colborn, James; Khudyakov, Yury; Drobenuic, Jan; Xia, Guo-Liang; Wood, Hattie; Moore, Zack

    2013-07-01

    Acute hepatitis B virus (HBV) infections have been reported in long-term care facilities (LTCFs), primarily associated with infection control breaks during assisted blood glucose monitoring. We investigated HBV outbreaks that occurred in separate skilled nursing facilities (SNFs) to determine factors associated with transmission. Outbreak investigation with case-control studies. Two SNFs (facilities A and B) in Durham, North Carolina, during 2009-2010. Residents with acute HBV infection and controls randomly selected from HBV-susceptible residents during the outbreak period. After initial cases were identified, screening was offered to all residents, with repeat testing 3 months later for HBV-susceptible residents. Molecular testing was performed to assess viral relatedness. Infection control practices were observed. Case-control studies were conducted to evaluate associations between exposures and acute HBV infection in each facility. Six acute HBV cases were identified in each SNF. Viral phylogenetic analysis revealed a high degree of HBV relatedness within, but not between, facilities. No evaluated exposures were significantly associated with acute HBV infection in facility A; those associated with infection in facility B (all odds ratios >20) included injections, hospital or emergency room visits, and daily blood glucose monitoring. Observations revealed absence of trained infection control staff at facility A and suboptimal hand hygiene practices during blood glucose monitoring and insulin injections at facility B. These outbreaks underscore the vulnerability of LTCF residents to acute HBV infection, the importance of surveillance and prompt investigation of incident cases, and the need for improved infection control education to prevent transmission.

  18. Small size neutron tube UNG-1

    International Nuclear Information System (INIS)

    Bespalov, D.F.; Mints, A.Z.; Shkol'nikov, A.S.

    A tube UNG-1 (universal neutron gas-filled) is designed for the use in the well neutron generators IGN-1 and IGN-1-M (a pulse neutron generator). Their serial production in the USSR has been started in 1963. At the same year, the serial production of the tubes UNG-1 has been started. Thus, this tube is the first serial logging accelerating tube in the USSR. A Penning source, equipped with a hot cathode, was selected as an ion source of the tube

  19. Models for Automated Tube Performance Calculations

    International Nuclear Information System (INIS)

    Brunkhorst, C.

    2002-01-01

    High power radio-frequency systems, as typically used in fusion research devices, utilize vacuum tubes. Evaluation of vacuum tube performance involves data taken from tube operating curves. The acquisition of data from such graphical sources is a tedious process. A simple modeling method is presented that will provide values of tube currents for a given set of element voltages. These models may be used as subroutines in iterative solutions of amplifier operating conditions for a specific loading impedance

  20. Tube for irradiation equipment

    International Nuclear Information System (INIS)

    Goehrich, K.; Vogt, H.

    1979-01-01

    This patent describes a tube for irradiation equipment for limiting an emergent beam, with a baseplate, possessing a central aperture, intended for attaching to the equipment, as well as four carrier plates, each of which possesses a limiting edge and a sliding edge located at right angles thereto. The carrier plates are located parallel to the baseplate, the limiting edge of each carrier plate resting against the sliding edge of the adjacent carrier plate and each of the two mutually opposite pairs of carrier plates being displaceable, parallel to the direction of its sliding edges and symmetrically to the center of the transmission aperture, for the purpose of continuously varying the transmission aperture defined by the limiting edges, during which displacement each of the displaced carrier plates carries with it the carrier plate, resting against the limiting edge of the former plate, parallel to the direction of the limiting edge of the latter plate. 8 claims

  1. Blood meal sources of wild and domestic Triatoma infestans (Hemiptera: Reduviidae) in Bolivia: connectivity between cycles of transmission of Trypanosoma cruzi.

    Science.gov (United States)

    Buitrago, Rosio; Bosseno, Marie-France; Depickère, Stéphanie; Waleckx, Etienne; Salas, Renata; Aliaga, Claudia; Barnabé, Christian; Brenière, Simone Frédérique

    2016-04-18

    Chagas disease is a major public health problem in Latin America. Its etiologic agent, Trypanosoma cruzi, is mainly transmitted through the contaminated faeces of blood-sucking insects called triatomines. Triatoma infestans is the main vector in various countries in South America and recently, several foci of wild populations of this species have been described in Bolivia and other countries. These wild populations are suspected of affecting the success of insecticide control campaigns being carried out in South America. To assess the risk that these T. infestans populations pose to human health, it is helpful to determine blood meal sources. In the present work, blood meals were identified in various Bolivian wild T. infestans populations and in three specific areas, in both wild and intra-peridomestic populations to assess the links between wild and domestic cycles of T. cruzi transmission. PCR-HDA and sequencing of Cytb gene were used to identify these blood meal sources. Fourteen vertebrate species were identified as wild blood meal sources. Of those, the most prevalent species were two Andean endemic rodents, Octodontomys gliroides (36%) and Galea musteloides (30%), while humans were the third most prevalent source (18.7%). Of 163 blood meals from peridomestic areas, more than half were chickens, and the others were generally domestic animals or humans. Interestingly, blood from wild animals was identified in triatomines captured in the peridomestic and domestic environment, and blood from domestic animals was found in triatomines captured in the wild, revealing links between wild and domestic cycles of T. cruzi transmission. The current study suggests that wild T. infestans attack humans in the wild, but is also able to bite humans in domestic settings before going back to its natural environment. These results support the risk to human health posed by wild populations of T. infestans.

  2. Electron tube

    Science.gov (United States)

    Suyama, Motohiro [Hamamatsu, JP; Fukasawa, Atsuhito [Hamamatsu, JP; Arisaka, Katsushi [Los Angeles, CA; Wang, Hanguo [North Hills, CA

    2011-12-20

    An electron tube of the present invention includes: a vacuum vessel including a face plate portion made of synthetic silica and having a surface on which a photoelectric surface is provided, a stem portion arranged facing the photoelectric surface and made of synthetic silica, and a side tube portion having one end connected to the face plate portion and the other end connected to the stem portion and made of synthetic silica; a projection portion arranged in the vacuum vessel, extending from the stem portion toward the photoelectric surface, and made of synthetic silica; and an electron detector arranged on the projection portion, for detecting electrons from the photoelectric surface, and made of silicon.

  3. Chest tube insertion

    Science.gov (United States)

    Chest drainage tube insertion; Insertion of tube into chest; Tube thoracostomy; Pericardial drain ... Be careful there are no kinks in your tube. The drainage system should always sit upright and be placed ...

  4. Transmission thresholds for dengue in terms of Aedes aegypti pupae per person with discussion of their utility in source reduction efforts.

    Science.gov (United States)

    Focks, D A; Brenner, R J; Hayes, J; Daniels, E

    2000-01-01

    The expense and ineffectiveness of drift-based insecticide aerosols to control dengue epidemics has led to suppression strategies based on eliminating larval breeding sites. With the notable but short-lived exceptions of Cuba and Singapore, these source reduction efforts have met with little documented success; failure has chiefly been attributed to inadequate participation of the communities involved. The present work attempts to estimate transmission thresholds for dengue based on an easily-derived statistic, the standing crop of Aedes aegypti pupae per person in the environment. We have developed these thresholds for use in the assessment of risk of transmission and to provide targets for the actual degree of suppression required to prevent or eliminate transmission in source reduction programs. The notion of thresholds is based on 2 concepts: the mass action principal-the course of an epidemic is dependent on the rate of contact between susceptible hosts and infectious vectors, and threshold theory-the introduction of a few infectious individuals into a community of susceptible individuals will not give rise to an outbreak unless the density of vectors exceeds a certain critical level. We use validated transmission models to estimate thresholds as a function of levels of pre-existing antibody levels in human populations, ambient air temperatures, and size and frequency of viral introduction. Threshold levels were estimated to range between about 0.5 and 1.5 Ae. aegypti pupae per person for ambient air temperatures of 28 degrees C and initial seroprevalences ranging between 0% to 67%. Surprisingly, the size of the viral introduction used in these studies, ranging between 1 and 12 infectious individuals per year, was not seen to significantly influence the magnitude of the threshold. From a control perspective, these results are not particularly encouraging. The ratio of Ae. aegypti pupae to human density has been observed in limited field studies to range

  5. Atmosphere in a Test Tube

    Science.gov (United States)

    Claudi, R.; Pace, E.; Ciaravella, A.; Micela, G.; Piccioni, G.; Billi, D.; Cestelli Guidi, M.; Coccola, L.; Erculiani, M. S.; Fedel, M.; Galletta, G.; Giro, E.; La Rocca, N.; Morosinotto, T.; Poletto, L.; Schierano, D.; Stefani, S.

    The ancestor philosophers' dream of thousand of new world is finally realised: more than 1800 extrasolar planets have been discovered in the neighborhood of our Sun. Most of them are very different from those we used to know in our Solar System. Others orbit the Habitable Zone (HZ) of their parent stars. Space missions, as JWST and the very recently proposed ARIEL, or ground based instruments, like SPHERE@VLT, GPI@GEMINI and EPICS@ELT, have been proposed and built to measure the atmospheric transmission, reflection and emission spectra over a wide wavelength range of these new worlds. In order to interpret the spectra coming out by this new instrumentation, it is important to know in detail the optical characteristics of gases in the typical physical conditions of the planetary atmospheres and how those characteristics could be affected by radiation driven photochemical and bio-chemical reaction. Insights in this direction can be achieved from laboratory studies of simulated planetary atmosphere of different pressure and temperature conditions under the effects of radiation sources, used as proxies of different bands of the stellar emission. ''Atmosphere in a Test Tube'' is a collaboration among several Italian astronomical, biological and engineering institutes in order to share their experiencece in performing laboratory experiments on several items concerning extrasolar planet atmospheres.

  6. Ferret badger rabies origin and its revisited importance as potential source of rabies transmission in Southeast China

    Directory of Open Access Journals (Sweden)

    Liu Ye

    2010-08-01

    Full Text Available Abstract Background The frequent occurrence of ferret badger-associated human rabies cases in southeast China highlights the lack of laboratory-based surveillance and urges revisiting the potential importance of this animal in rabies transmission. To determine if the ferret badgers actually contribute to human and dog rabies cases, and the possible origin of the ferret badger-associated rabies in the region, an active rabies survey was conducted to determine the frequency of rabies infection and seroprevalence in dogs and ferret badgers. Methods A retrospective survey on rabies epidemics was performed in Zhejiang, Jiangxi and Anhui provinces in southeast China. The brain tissues from ferret badgers and dogs were assayed by fluorescent antibody test. Rabies virus was isolated and sequenced for phylogenetic analysis. The sera from ferret badgers and dogs were titrated using rabies virus neutralizing antibodies (VNA test. Results The ferret badgers presented a higher percentage of rabies seroconversion than dogs did in the endemic region, reaching a maximum of 95% in the collected samples. Nine ferret badger-associated rabies viruses were isolated, sequenced, and were phylogenetically clustered as a separate group. Nucleotide sequence revealed 99.4-99.8% homology within the ferret badger isolates, and 83-89% homology to the dog isolates in the nucleoprotein and glycoprotein genes in the same rabies endemic regions. Conclusions Our data suggest ferret badger-associated rabies has likely formed as an independent enzootic originating from dogs during the long-term rabies infestation in southeast China. The eventual role of FB rabies in public health remains unclear. However, management of ferret badger bites, rabies awareness and control in the related regions should be an immediate need.

  7. Bats host diverse parvoviruses as possible origin of mammalian dependoparvoviruses and source for bat-swine interspecies transmission.

    Science.gov (United States)

    Lau, Susanna K P; Ahmed, Syed Shakeel; Tsoi, Hoi-Wah; Yeung, Hazel C; Li, Kenneth S M; Fan, Rachel Y Y; Zhao, Pyrear S H; Lau, Candy C C; Lam, Carol S F; Choi, Kelvin K F; Chan, Ben C H; Cai, Jian-Piao; Wong, Samson S Y; Chen, Honglin; Zhang, Hai-Lin; Zhang, Libiao; Wang, Ming; Woo, Patrick C Y; Yuen, Kwok-Yung

    2017-11-06

    Compared to the enormous species diversity of bats, relatively few parvoviruses have been reported. We detected diverse and potentially novel parvoviruses from bats in Hong Kong and mainland China. Parvoviruses belonging to Amdoparvovirus, Bocaparvovirus and Dependoparvovirus were detected in alimentary, liver and spleen samples from 16 different chiropteran species of five families by PCR. Phylogenetic analysis of partial helicase sequences showed that they potentially belonged to 25 bocaparvovirus, three dependoparvovirus and one amdoparvovirus species. Nearly complete genome sequencing confirmed the existence of at least four novel bat bocaparvovirus species (Rp-BtBoV1 and Rp-BtBoV2 from Rhinolophus pusillus, Rs-BtBoV2 from Rhinolophus sinicus and Rol-BtBoV1 from Rousettus leschenaultii) and two novel bat dependoparvovirus species (Rp-BtAAV1 from Rhinolophus pusillus and Rs-BtAAV1 from Rhinolophus sinicus). Rs-BtBoV2 was closely related to Ungulate bocaparvovirus 5 with 93, 72.1 and 78.7 % amino acid identities in the NS1, NP1 and VP1/VP2 genes, respectively. The detection of bat bocaparvoviruses, including Rs-BtBoV2, closely related to porcine bocaparvoviruses, suggests recent interspecies transmission of bocaparvoviruses between bats and swine. Moreover, Rp-BtAAV1 and Rs-BtAAV1 were most closely related to human AAV1 with 48.7 and 57.5 % amino acid identities in the rep gene. The phylogenetic relationship between BtAAVs and other mammalian AAVs suggests bats as the ancestral origin of mammalian AAVs. Furthermore, parvoviruses of the same species were detected from multiple bat species or families, supporting the ability of bat parvoviruses to cross species barriers. The results extend our knowledge on the diversity of bat parvoviruses and the role of bats in parvovirus evolution and emergence in humans and animals.

  8. Ultra-high pitch chest computed tomography at 70 kVp tube voltage in an anthropomorphic pediatric phantom and non-sedated pediatric patients: Initial experience with 3rd generation dual-source CT.

    Science.gov (United States)

    Hagelstein, Claudia; Henzler, Thomas; Haubenreisser, Holger; Meyer, Mathias; Sudarski, Sonja; Schoenberg, Stefan O; Neff, K Wolfgang; Weis, Meike

    2016-12-01

    Minimizing radiation dose while at the same time preserving image quality is of particular importance in pediatric chest CT. Very recently, CT imaging with a tube voltage of 70 kVp has become clinically available. However, image noise is inversely proportional to the tube voltage. We aimed to investigate radiation dose and image quality of pediatric chest CT performed at 70 kVp in an anthropomorphic pediatric phantom as well as in clinical patients. An anthropomorphic pediatric phantom, which resembles a one-year-old child in physiognomy, was scanned on the 3 rd generation dual-source CT (DSCT) system at 70 kVp and 80 kVp and a fixed ultra low tube-current of 8 mAs to solely evaluate the impact of lowering tube voltage. After the phantom measurements, 18 pediatric patients (mean 29.5 months; range 1-91 months; 21 examinations) underwent 3.2 high-pitch chest CT on the same DSCT system at 70 kVp tube voltage without any sedation. Radiation dose and presence of motion artifacts was compared to a retrospectively identified patient cohort examined at 80 kVp on a 16-slice single-source-CT (SSCT; n=15; 14/15 with sedation; mean 30.7 months; range 0-96 months; pitch=1.5) or on a 2 nd generation DSCT without any sedation (n=6; mean 32.8 months; range 4-61 months; pitch=3.2). Radiation dose in the phantom scans was reduced by approximately 40% when using a tube voltage of 70 kVp instead of 80 kVp. In the pediatric patient group examined at 70 kVp age-specific effective dose (ED; mean 0.5±0.2 mSv) was significantly lower when compared to the retrospective cohort scanned at 80 kVp on the 16-slice-SSCT (mean ED: 1.0±0.3 mSv; pCT examinations showed any motion artifacts whereas 13/15 examinations of the retrospective patient cohort scanned at 80 kVp with a pitch of 1.5 showed motion artifacts. 3.2 high-pitch chest CT performed with 70 kVp significantly reduces radiation dose when compared to 80 kVp while at the same time provides good image quality without any motion artifacts

  9. A spatial individual-based model predicting a great impact of copious sugar sources and resting sites on survival of Anopheles gambiae and malaria parasite transmission

    Science.gov (United States)

    Zhu, Lin; Qualls, Whitney A.; Marshall, John M; Arheart, Kris L.; DeAngelis, Donald L.; McManus, John W.; Traore, Sekou F.; Doumbia, Seydou; Schlein, Yosef; Muller, Gunter C.; Beier, John C.

    2015-01-01

    outdoor resting sites significantly increase the survival and human biting rates of An. gambiae mosquitoes. Survival of An. gambiae is more supported by random distribution of sugar sources than clustering of sugar sources around resting sites or houses. Density and spatial distribution of natural sugar sources and outdoor resting sites modulate vector populations and human biting rates, and thus malaria parasite transmission.

  10. photomultiplier tubes

    CERN Multimedia

    photomultiplier tubes. A device to convert light into an electric signal (the name is often abbreviated to PM). Photomultipliers are used in all detectors based on scintillating material (i.e. based on large numbers of fibres which produce scintillation light at the passage of a charged particle). A photomultiplier consists of 3 main parts: firstly, a photocathode where photons are converted into electrons by the photoelectric effect; secondly, a multiplier chain consisting of a serie of dynodes which multiply the number of electron; finally, an anode, which collects the resulting current.

  11. photomultiplier tube

    CERN Multimedia

    photomultiplier tubes. A device to convert light into an electric signal (the name is often abbreviated to PM). Photomultipliers are used in all detectors based on scintillating material (i.e. based on large numbers of fibres which produce scintillation light at the passage of a charged particle). A photomultiplier consists of 3 main parts: firstly, a photocathode where photons are converted into electrons by the photoelectric effect; secondly, a multiplier chain consisting of a serie of dynodes which multiply the number of electron; finally, an anode, which collects the resulting current.

  12. Evaluating YouTube as a Source of Patient Education on the Role of the Hospitalist: A Cross-Sectional Study.

    Science.gov (United States)

    Hudali, Tamer; Papireddy, Muralidhar; Bhattarai, Mukul; Deckard, Alan; Hingle, Susan

    2017-01-10

    Hospital medicine is a relatively new specialty field, dedicated to the delivery of comprehensive medical care to hospitalized patients. YouTube is one of the most frequently used websites, offering access to a gamut of videos from self-produced to professionally made. The aim of our study was to determine the adequacy of YouTube as an effective means to define and depict the role of hospitalists. YouTube was searched on November 17, 2014, using the following search words: "hospitalist," "hospitalist definition," "what is the role of a hospitalist," "define hospitalist," and "who is a hospitalist." Videos found only in the first 10 pages of each search were included. Non-English, noneducational, and nonrelevant videos were excluded. A novel 7-point scoring tool was created by the authors based on the definition of a hospitalist adopted by the Society of Hospital Medicine. Three independent reviewers evaluated, scored, and classified the videos into high, intermediate, and low quality based on the average score. A total of 102 videos out of 855 were identified as relevant and included in the analysis. Videos uploaded by academic institutions had the highest mean score. Only 6 videos were classified as high quality, 53 as intermediate quality, and 42 as low quality, with 82.4% (84/102) of the videos scoring an average of 4 or less. Most videos found in the search of a hospitalist definition are inadequate. Leading medical organizations and academic institutions should consider producing and uploading quality videos to YouTube to help patients and their families better understand the roles and definition of the hospitalist. ©Tamer Hudali, Muralidhar Papireddy, Mukul Bhattarai, Alan Deckard, Susan Hingle. Originally published in the Interactive Journal of Medical Research (http://www.i-jmr.org/), 10.01.2017.

  13. Sources

    International Nuclear Information System (INIS)

    Duffy, L.P.

    1991-01-01

    This paper discusses the sources of radiation in the narrow perspective of radioactivity and the even narrow perspective of those sources that concern environmental management and restoration activities at DOE facilities, as well as a few related sources. Sources of irritation, Sources of inflammatory jingoism, and Sources of information. First, the sources of irritation fall into three categories: No reliable scientific ombudsman to speak without bias and prejudice for the public good, Technical jargon with unclear definitions exists within the radioactive nomenclature, and Scientific community keeps a low-profile with regard to public information. The next area of personal concern are the sources of inflammation. This include such things as: Plutonium being described as the most dangerous substance known to man, The amount of plutonium required to make a bomb, Talk of transuranic waste containing plutonium and its health affects, TMI-2 and Chernobyl being described as Siamese twins, Inadequate information on low-level disposal sites and current regulatory requirements under 10 CFR 61, Enhanced engineered waste disposal not being presented to the public accurately. Numerous sources of disinformation regarding low level radiation high-level radiation, Elusive nature of the scientific community, The Federal and State Health Agencies resources to address comparative risk, and Regulatory agencies speaking out without the support of the scientific community

  14. Low concentration contrast medium for dual-source computed tomography coronary angiography by a combination of iterative reconstruction and low-tube-voltage technique: Feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Minwen, E-mail: zhengmw2007@163.com; Liu, Ying, E-mail: yingyinglyly@126.com; Wei, Mengqi, E-mail: weimengqi2008@163.com; Wu, Yongjie, E-mail: wu18291988526@163.com; Zhao, Hongliang, E-mail: zhaohl1980@163.com; Li, Jian, E-mail: xjyylj@yeah.net

    2014-02-15

    Objectives: To assess the impact of low-concentration contrast medium on vascular enhancement, image quality and radiation dose of coronary CT angiography (cCTA) by using a combination of iterative reconstruction (IR) and low-tube-voltage technique. Materials and methods: One hundred patients were prospectively randomized to two types of contrast medium and underwent prospective electrocardiogram-triggering cCTA (Definition Flash, Siemens Healthcare; collimation: 128 mm × 0.6 mm; tube current: 300 mA s). Fifty patients received Iopromide 370 were scanned using the conventional tube setting (100 kVp or 120 kVp if BMI ≥ 25 kg/m{sup 2}) and reconstructed with filtered back projection (FBP). Fifty patients received Iodixanol 270 were scanned using the low-tube-voltage (80 kVp or 100 kVp if BMI ≥ 25 kg/m{sup 2}) technique and reconstructed with IR. CT attenuation was measured in coronary artery and other anatomical regions. Noise, image quality and radiation dose were compared. Results: Compared with two Iopromide 370 subgroups, Iomeprol 270 subgroups showed no significant difference in CT attenuation (576.63 ± 95.50 vs. 569.51 ± 118.93 for BMI < 25 kg/m{sup 2}, p = 0.647 and 394.19 ± 68.09 vs. 383.72 ± 63.11 for BMI ≥ 25 kg/m{sup 2}, p = 0.212), noise (in various anatomical regions of interest) and image quality (3.5 vs. 4.0, p = 0.13), but significantly (0.41 ± 0.17 vs. 0.94 ± 0.45 for BMI < 25 kg/m{sup 2}, p < 0.001 and 1.14 ± 0.24 vs. 2.37 ± 0.69 for BMI ≥ 25 kg/m{sup 2}, p < 0.001) lower radiation dose, which reflects dose saving of 56.4% and 51.9%, respectively. Conclusions: Combined IR with low-tube-voltage technique, a low-concentration contrast medium of 270 mg I/ml can still maintain the contrast enhancement without impairing image quality, as well as significantly lower the radiation dose.

  15. Flux tubes at finite temperature

    Energy Technology Data Exchange (ETDEWEB)

    Cea, Paolo [INFN, Sezione di Bari,Via G. Amendola 173, I-70126 Bari (Italy); Dipartimento di Fisica dell’Università di Bari,Via G. Amendola 173, I-70126 Bari (Italy); Cosmai, Leonardo [INFN, Sezione di Bari,Via G. Amendola 173, I-70126 Bari (Italy); Cuteri, Francesca; Papa, Alessandro [Dipartimento di Fisica, Università della Calabria & INFN-Cosenza,Ponte Bucci, cubo 31C, I-87036 Rende (Cosenza) (Italy)

    2016-06-07

    The chromoelectric field generated by a static quark-antiquark pair, with its peculiar tube-like shape, can be nicely described, at zero temperature, within the dual superconductor scenario for the QCD confining vacuum. In this work we investigate, by lattice Monte Carlo simulations of the SU(3) pure gauge theory, the fate of chromoelectric flux tubes across the deconfinement transition. We find that, if the distance between the static sources is kept fixed at about 0.76 fm ≃1.6/√σ and the temperature is increased towards and above the deconfinement temperature T{sub c}, the amplitude of the field inside the flux tube gets smaller, while the shape of the flux tube does not vary appreciably across deconfinement. This scenario with flux-tube “evaporation” above T{sub c} has no correspondence in ordinary (type-II) superconductivity, where instead the transition to the phase with normal conductivity is characterized by a divergent fattening of flux tubes as the transition temperature is approached from below. We present also some evidence about the existence of flux-tube structures in the magnetic sector of the theory in the deconfined phase.

  16. TH-C-18A-12: Evaluation of the Impact of Body Size and Tube Output Limits in the Optimization of Fast Scanning with High-Pitch Dual Source CT

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez Giraldo, J [Siemens Medical Solutions USA, Inc (United States); Mileto, A.; Hurwitz, L.; Marin, D. [Duke University Medical Center, Durham NC (United States)

    2014-06-15

    Purpose: To evaluate the impact of body size and tube power limits in the optimization of fast scanning with high-pitch dual source CT (DSCT). Methods: A previously validated MERCURY phantom, made of polyethylene, with circular cross-section of diameters 16, 23, 30 and 37cm, and connected through tapered sections, was scanned using a second generation DSCT system. The DSCT operates with two independently controlled x-ray tube generators offering up to 200 kW power reserve (100 kW per tube). The entire length of the phantom (42cm) was scanned with two protocols using: A)Standard single-source CT (SSCT) protocol with pitch of 0.8, and B) DSCT protocol with high-pitch values ranging from 1.6 to 3.2 (0.2 steps). All scans used 120 kVp with 150 quality reference mAs using automatic exposure control. Scanner radiation output (CTDIvol) and effective mAs values were extracted retrospectively from DICOM files for each slice. Image noise was recorded. All variables were assessed relative to phantom diameter. Results: With standard-pitch SSCT, the scanner radiation output (and tube-current) were progressively adapted with increasing size, from 6 mGy (120 mAs) up to 15 mGy (270 mAs) from the thinnest (16cm) to the thickest diameter (37 cm), respectively. By comparison, using high-pitch (3.2), the scanner output was bounded at about 8 mGy (140 mAs), independent of phantom diameter. Although relative to standard-pitch, the high-pitch led to lower radiation output for the same scan, the image noise was higher, particularly for larger diameters. To match the radiation output adaptation of standard-pitch, a high-pitch mode of 1.6 was needed, with the advantage of scanning twice as fast. Conclusion: To maximize the benefits of fast scanning with high-pitch DSCT, the body size and tube power limits of the system need to be considered such that a good balance between speed of acquisition and image quality are warranted. JCRG is an employee of Siemens Medical Solutions USA Inc.

  17. sources

    Directory of Open Access Journals (Sweden)

    Shu-Yin Chiang

    2002-01-01

    Full Text Available In this paper, we study the simplified models of the ATM (Asynchronous Transfer Mode multiplexer network with Bernoulli random traffic sources. Based on the model, the performance measures are analyzed by the different output service schemes.

  18. A method of multi-crack shape identification from eddy current testing signals of steam generator tubes including support plates as noise sources

    International Nuclear Information System (INIS)

    Nagaya, Yoshiaki; Endo, Hisashi; Takagi, Toshiyuki; Uchimoto, Tetsuya

    2005-01-01

    This paper deals with identifying multiple cracks from eddy current testing (ECT) signals obtained in a steam generator tube with a support plate and deposits. Assume two-dimensionally scanned ECT signals to be a picture image, then the signal processing by a multi-frequency technique eliminates noise caused by the support plate and deposits. A template matching with help of genetic algorithms detects number and positions of cracks from the image after the signal processing. Inverse analysis estimates the crack profile based on the predicted position of cracks. The number and positions of the cracks are sufficiently well predicted. Crack shape reconstructions are achieved with a satisfactory degree of accuracy. (author)

  19. Genetic analysis and CRISPR typing of Salmonella enterica serovar Enteritidis from different sources revealed potential transmission from poultry and pig to human.

    Science.gov (United States)

    Li, Qiuchun; Wang, Xin; Yin, Kequan; Hu, Yachen; Xu, Haiyan; Xie, Xiaolei; Xu, Lijuan; Fei, Xiao; Chen, Xiang; Jiao, Xinan

    2018-02-02

    Salmonella enterica serovar Enteritidis (S. Enteritidis) is one of the most prevalent serotypes in Salmonella isolated from poultry and the most commonly reported cause of human salmonellosis. In this study, we aimed to assess the genetic diversity of 329 S. Enteritidis strains isolated from different sources from 2009 to 2016 in China. Clustered regularly interspaced short palindromic repeat (CRISPR) typing was used to characterize these 262 chicken clinical isolates, 38 human isolates, 18 pig isolates, six duck isolates, three goose isolates and two isolates of unknown source. A total of 18 Enteritidis CRISPR types (ECTs) were identified, with ECT2, ECT8 and ECT4 as the top three ECTs. CRISPR typing identified ECT2 as the most prevalent ECT, which accounted for 41% of S. Enteritidis strains from all the sources except duck. ECT9 and ECT13 were identified in both pig and human isolates and revealed potential transmission from pig to human. A cluster analysis distributed 18 ECTs, including the top three ECTs, into four lineages with LI as the predominant lineage. Forty-eight out of 329 isolates were subjected to whole genome sequence typing, which divided them into four clusters, with Cluster I as the predominant cluster. Cluster I included 92% (34/37) of strains located in LI identified from the CRISPR typing, confirming the good correspondence between both typing methods. In addition, the CRISPR typing also revealed the close relationship between ECTs and isolated areas, confirming that CRISPR spacers might be obtained by bacteria from the unique phage or plasmid pools in the environment. However, further analysis is needed to determine the function of CRISPR-Cas systems in Salmonella and the relationship between spacers and the environment. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Meta-analysis to estimate the load of Leptospira excreted in urine: beyond rats as important sources of transmission in low-income rural communities.

    Science.gov (United States)

    Barragan, Veronica; Nieto, Nathan; Keim, Paul; Pearson, Talima

    2017-01-28

    Leptospirosis is a major zoonotic disease with widespread distribution and a large impact on human health. Carrier animals excrete pathogenic Leptospira primarily in their urine. Infection occurs when the pathogen enters a host through mucosa or small skin abrasions. Humans and other animals are exposed to the pathogen by direct contact with urine, contaminated soil or water. While many factors influence environmental cycling and the transmission of Leptospira to humans, the load of pathogenic Leptospira in the environment is likely to play a major role. Peridomestic rats are often implicated as a potential source of human disease; however exposure to other animals is a risk factor as well. The aim of this report is to highlight the importance of various carrier animals in terms of the quantity of Leptospira shed into the environment. For this, we performed a systematic literature review and a meta-analysis of the amount of pathogen that various animal species shed in their urine. The quantity of pathogen has been reported for cows, deer, dogs, humans, mice, and rats, in a total of 14 research articles. We estimated the average Leptospira per unit volume shed by each animal species, and the daily environmental contribution by considering the total volume of urine excreted by each carrier animal. Rats excrete the highest quantity of Leptospira per millilitre of urine (median = 5.7 × 10 6  cells), but large mammals excrete much more urine and thus shed significantly more Leptospira per day (5.1 × 10 8 to 1.3 × 10 9  cells). Here we illustrate how, in a low-income rural Ecuadorian community, host population demographics, and prevalence of Leptospira infection can be integrated with estimates of shed Leptospira to suggest that peridomestic cattle may be more important than rats in environmental cycling and ultimately, transmission to humans.

  1. Eustachian tube patency

    Science.gov (United States)

    Eustachian tube patency refers to how much the eustachian tube is open. The eustachian tube runs between the middle ear and the throat. It controls the pressure behind the eardrum and middle ear space. This helps keep ...

  2. Feeding tube - infants

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007235.htm Feeding tube - infants To use the sharing features on this page, please enable JavaScript. A feeding tube is a small, soft, plastic tube placed ...

  3. Brushless dc motor uses electron beam switching tube as commutator

    Science.gov (United States)

    Studer, P.

    1965-01-01

    Electron beam switching tube eliminates physical contact between rotor and stator in brushless dc motor. The tube and associated circuitry control the output of a dc source to sequentially energize the motor stator windings.

  4. Microbial ecology of Campylobacter jejuni in a United Kingdom chicken supply chain: intermittent common source, vertical transmission, and amplification by flock propagation.

    Science.gov (United States)

    Pearson, A D; Greenwood, M H; Feltham, R K; Healing, T D; Donaldson, J; Jones, D M; Colwell, R R

    1996-12-01

    A study of Campylobacter jejuni on a broiler chicken farm between 1989 and 1994 gave an estimated isolation rate of 27% (3,304 of 12,233) from a 0.9% sample of 1.44 million broiler chickens from six to eight sheds over 32 consecutive rearing flocks comprising 251 broiler shed flocks. During the study, C. jejuni was found in 35.5% of the 251 shed flocks but only 9.2% (23 of 251) had Campylobacter isolates in successive flocks, with 9 of those 23 sheds having the same serotype between consecutive flocks, indicating a low level of transmission between flocks. Analysis of a systematic sample of 484 of 3,304 (14.6%) C. jejuni isolates showed that 85% were of 10 serotype complexes but 58% were of 3 serotype complexes, indicating a high degree of strain similarity throughout the entire study. The three commonest types were detected in 8 of 32 flocks during the 5-year study period, suggesting an intermittent common external Campylobacter source. This hypothesis was tested by a retrospective cohort analysis of C. jejuni rates and types by reference to hatchery supplier of the 1-day-old chicks. Isolation rates of C. jejuni and frequency distribution of types were determined in 6-week-old broiler chickens identified by the hatchery supplying the original chicks. The isolation rate of C. jejuni in broilers, supplied by hatchery A, was 17.6%, compared to 42.9% (P hatchery B. In two instances, when both hatcheries were used to stock the same farm flock, Campylobacter isolates were found only in those sheds with chicks supplied by hatchery B. Thus, the frequency distribution of Campylobacter types for chickens supplied by the two hatcheries over the 5-year period showed marked dissimilarity. These findings suggest that the isolation rate and type of Campylobacter isolates in broiler chickens was associated with the hatchery supplying chicks. The lack of diversity of types and the intermittent high positivity of sheds is evidence for a common source of C. jejuni introduced by

  5. Tube holding system

    International Nuclear Information System (INIS)

    Cunningham, R.C.

    1978-01-01

    A tube holding rig is described for the lateral support of tubes arranged in tight parcels in a heat exchanger. This tube holding rig includes not less than two tube supporting assemblies, with a space between them, located crosswise with respect to the tubes, each supporting assembly comprising a first set of parallel components in contact with the tubes, whilst a second set of components is also in contact with the tubes. These two sets of parts together define apertures through which the tubes pass [fr

  6. Optimizing Tube Precurvature to Enhance Elastic Stability of Concentric Tube Robots.

    Science.gov (United States)

    Ha, Junhyoung; Park, Frank C; Dupont, Pierre E

    2017-02-01

    Robotic instruments based on concentric tube technology are well suited to minimally invasive surgery since they are slender, can navigate inside small cavities and can reach around sensitive tissues by taking on shapes of varying curvature. Elastic instabilities can arise, however, when rotating one precurved tube inside another. In contrast to prior work that considered only tubes of piecewise constant precurvature, we allow precurvature to vary along the tube's arc length. Stability conditions for a planar tube pair are derived and used to formulate an optimal design problem. An analytic formulation of the optimal precurvature function is derived that achieves a desired tip orientation range while maximizing stability and respecting bending strain limits. This formulation also includes straight transmission segments at the proximal ends of the tubes. The result, confirmed by both numerical and physical experiment, enables designs with enhanced stability in comparison to designs of constant precurvature.

  7. Parameters and design considerations for tomographic transmission scanners

    International Nuclear Information System (INIS)

    Pentlow, K.S.; Beattie, J.W.; Laughlin, J.S.

    1976-01-01

    The design of transverse axial transmission scanners for reconstruction tomography involves many interrelated parameters and conflicting requirements. We have investigated some of those parameters and their interactions and, where appropriate, attempted to optimize them. It is convenient to group the considerations under four headings: (1) Geometrical factors (basic configurations, rectilinear and fan geometry, moving detectors or static arrays, spatial response variations and field uniformity, and collimation); (2) Radiation energy and sources (Considerations here include transmission versus sensitivity, detector efficiency, collimator penetration, scattered radiation, patient dose, monochromatic versus polychromatic radiation and X-ray tubes versus radionuclide sources); (3) Detection systems (types of detector, detection modes and the rejection of scatter); and (4) Reconstruction mathematics and quantum noise. As a result of such considerations we have proposed a particular design which should have advantages in certain applications

  8. Distinct transmissibility features of TSE sources derived from ruminant prion diseases by the oral route in a transgenic mouse model (TgOvPrP4 overexpressing the ovine prion protein.

    Directory of Open Access Journals (Sweden)

    Jean-Noël Arsac

    Full Text Available Transmissible spongiform encephalopathies (TSEs are a group of fatal neurodegenerative diseases associated with a misfolded form of host-encoded prion protein (PrP. Some of them, such as classical bovine spongiform encephalopathy in cattle (BSE, transmissible mink encephalopathy (TME, kuru and variant Creutzfeldt-Jakob disease in humans, are acquired by the oral route exposure to infected tissues. We investigated the possible transmission by the oral route of a panel of strains derived from ruminant prion diseases in a transgenic mouse model (TgOvPrP4 overexpressing the ovine prion protein (A136R154Q171 under the control of the neuron-specific enolase promoter. Sources derived from Nor98, CH1641 or 87V scrapie sources, as well as sources derived from L-type BSE or cattle-passaged TME, failed to transmit by the oral route, whereas those derived from classical BSE and classical scrapie were successfully transmitted. Apart from a possible effect of passage history of the TSE agent in the inocula, this implied the occurrence of subtle molecular changes in the protease-resistant prion protein (PrPres following oral transmission that can raises concerns about our ability to correctly identify sheep that might be orally infected by the BSE agent in the field. Our results provide proof of principle that transgenic mouse models can be used to examine the transmissibility of TSE agents by the oral route, providing novel insights regarding the pathogenesis of prion diseases.

  9. Is YouTube Useful as a Source of Health Information for Adults With Type 2 Diabetes? A South Asian Perspective.

    Science.gov (United States)

    Leong, Amanda Y; Sanghera, Ravina; Jhajj, Jaspreet; Desai, Nandini; Jammu, Bikramjit Singh; Makowsky, Mark J

    2017-12-25

    To investigate the content, quality and popularity of information about type 2 diabetes available on YouTube. We searched YouTube with the terms Diabetes, Diabetes type 2, Diabetes South Asians, Diabetes Punjabi and Diabetes Hindi to identify videos concerning type 2 diabetes. A team of health-care providers independently classified the first 20 videos from each search as useful, misleading, or personal experience, rated them on a 5-point global quality scale (GQS) and categorized their content on a 26-point scale in duplicate. Useful videos were rated for reliability by using a 5-point modified DISCERN scale. Higher scores represent better quality, reliability and comprehensiveness. Of 100 videos, 71 met the inclusion criteria; 45 (63.4%) were rated as useful (median GQS, 3; interquartile range [IQR], 2 to 4); and 23 (32.4%) were deemed misleading (median GQS, 1; IQR, 1 to 2). Median reliability and content scores for useful videos were 3 (IQR, 2 to 3) and 5 (IQR, 3 to 10), respectively, and 6 videos met ≥ 4 of 5 reliability criteria. Overall, misleading videos were more popular than useful videos (median, 233 views/day; IQR, 26 to 523; vs. 8.3 views/day; IQR, 0.4 to 134.6; p<0.01). Culturally tailored videos were just as likely to be misleading and had similar GQS scores in comparison to nonculturally tailored videos (32.1% vs. 32.6% and 3 vs. 3, respectively). The quality of identified videos concerning type 2 diabetes was variable, and misleading videos were popular. Further creation and curation of high-quality video resources is required. Copyright © 2017 Diabetes Canada. Published by Elsevier Inc. All rights reserved.

  10. Dermatology on YouTube.

    Science.gov (United States)

    Boyers, Lindsay N; Quest, Tyler; Karimkhani, Chante; Connett, Jessica; Dellavalle, Robert P

    2014-06-15

    YouTube, reaches upwards of six billion users on a monthly basis and is a unique source of information distribution and communication. Although the influence of YouTube on personal health decision-making is well established, this study assessed the type of content and viewership on a broad scope of dermatology related content on YouTube. Select terms (i.e. dermatology, sun protection, skin cancer, skin cancer awareness, and skin conditions) were searched on YouTube. Overall, the results included 100 videos with over 47 million viewers. Advocacy was the most prevalent content type at 24% of the total search results. These 100 videos were "shared" a total of 101,173 times and have driven 6,325 subscriptions to distinct YouTube user pages. Of the total videos, 35% were uploaded by or featured an MD/DO/PhD in dermatology or other specialty/field, 2% FNP/PA, 1% RN, and 62% other. As one of the most trafficked global sites on the Internet, YouTube is a valuable resource for dermatologists, physicians in other specialties, and the general public to share their dermatology-related content and gain subscribers. However, challenges of accessing and determining evidence-based data remain an issue.

  11. Beta attenuation transmission system (BATS)

    Energy Technology Data Exchange (ETDEWEB)

    Hagan, R.C.; Fullbright, H.J.

    1977-01-01

    The beta attenuation transmission system (BATS) is an automated radiation gauge designed for quantitative measurement of component thickness in explosive detonators. The BATS was designed and built by Group M-1, the Nondestructive Testing Group, of the Los Alamos Scientific Laboratory to measure the areal thickness, in mg/cm/sup 2/, of a cylinder of high explosive (HE) enclosed within a plastic holder. The problem is to determine the density of the HE. A /sup 90/Sr source is collimated by a 0.25 x 1.59-mm slit, and the transmitted beta-particle flux is detected by a plastic scintillator, coupled to a photomultiplier tube. The detonator is transported through the radiation beam by a leadscrew, ballnut, stepping-motor combination. Continuous analog position data are available, derived from the output from a linear-actuated potentiometer attached to the scanner. A linear electrometer amplifies the detected signal, which is then integrated for a preselected time, to obtain the desired statistical accuracy. A microprocessor (..mu..P) is used to control the scanner position and to make the data readings at the assigned positions. The data are stored, and, at the completion of the scan, are processed into the desired format. The final answer is displayed to the operator or output to a peripheral device for permanent record. The characteristics of the radiation source, the collimator, the signal detection and conditioning, and the final results are described in detail. The scanner and the microprocessor control system are briefly outlined.

  12. Beta attenuation transmission system (BATS)

    International Nuclear Information System (INIS)

    Hagan, R.C.; Fullbright, H.J.

    1977-01-01

    The beta attenuation transmission system (BATS) is an automated radiation gauge designed for quantitative measurement of component thickness in explosive detonators. The BATS was designed and built by Group M-1, the Nondestructive Testing Group, of the Los Alamos Scientific Laboratory to measure the areal thickness, in mg/cm 2 , of a cylinder of high explosive (HE) enclosed within a plastic holder. The problem is to determine the density of the HE. A 90 Sr source is collimated by a 0.25 x 1.59-mm slit, and the transmitted beta-particle flux is detected by a plastic scintillator, coupled to a photomultiplier tube. The detonator is transported through the radiation beam by a leadscrew, ballnut, stepping-motor combination. Continuous analog position data are available, derived from the output from a linear-actuated potentiometer attached to the scanner. A linear electrometer amplifies the detected signal, which is then integrated for a preselected time, to obtain the desired statistical accuracy. A microprocessor (μP) is used to control the scanner position and to make the data readings at the assigned positions. The data are stored, and, at the completion of the scan, are processed into the desired format. The final answer is displayed to the operator or output to a peripheral device for permanent record. The characteristics of the radiation source, the collimator, the signal detection and conditioning, and the final results are described in detail. The scanner and the microprocessor control system are briefly outlined

  13. Ongoing Horizontal and Vertical Transmission of Virulence Genes and papA Alleles among Escherichia coli Blood Isolates from Patients with Diverse-Source Bacteremia

    Science.gov (United States)

    Johnson, James R.; O'Bryan, Timothy T.; Kuskowski, Michael; Maslow, Joel N.

    2001-01-01

    The phylogenetic distributions of multiple putative virulence factors (VFs) and papA (P fimbrial structural subunit) alleles among 182 Escherichia coli blood isolates from patients with diverse-source bacteremia were defined. Phylogenetic correspondence among these strains, the E. coli Reference (ECOR) collection, and other collections of extraintestinal pathogenic E. coli (ExPEC) was assessed. Although among the 182 bacteremia isolates phylogenetic group B2 predominated, exhibited the greatest concentration of individual VFs, and contained the largest number of familiar virulent clones, other phylogenetic groups exhibited greater concentrations of certain VFs than did group B2 and included several additional virulent clones. Certain of the newly detected VF genes, e.g., fyuA (yersiniabactin; 76%) and focG (F1C fimbriae; 25%), were as prevalent or more prevalent than their more familiar traditional counterparts, e.g., iut (aerobactin; 57%) and sfaS (S fimbriae; 14%), thus possibly offering additional useful targets for preventive interventions. Considerable diversity of VF profiles was observed at every level within the phylogenetic tree, including even within individual lineages. This suggested that many different pathways can lead to extraintestinal virulence in E. coli and that the evolution of ExPEC, which involves extensive horizontal transmission of VFs and continuous remodeling of pathogenicity-associated islands, is a highly active, ongoing process. PMID:11500406

  14. Ultra-high pitch chest computed tomography at 70 kVp tube voltage in an anthropomorphic pediatric phantom and non-sedated pediatric patients. Initial experience with 3{sup rd} generation dual-source CT

    Energy Technology Data Exchange (ETDEWEB)

    Hagelstein, Claudia; Henzler, Thomas; Haubenreisser, Holger; Meyer, Mathias; Sudarski, Sonja; Schoenberg, Stefan O.; Neff, K. Wolfgang; Weis, Meike [Univ. Medical Center Mannheim (Germany). Inst. of Clinical Radiology and Nuclear Medicine

    2016-07-01

    Minimizing radiation dose while at the same time preserving image quality is of particular importance in pediatric chest CT. Very recently, CT imaging with a tube voltage of 70 kVp has become clinically available. However, image noise is inversely proportional to the tube voltage. We aimed to investigate radiation dose and image quality of pediatric chest CT performed at 70 kVp in an anthropomorphic pediatric phantom as well as in clinical patients. An anthropomorphic pediatric phantom, which resembles a one-year-old child in physiognomy, was scanned on the 3{sup rd} generation dual-source CT (DSCT) system at 70 kVp and 80 kVp and a fixed ultra low tube-current of 8 mAs to solely evaluate the impact of lowering tube voltage. After the phantom measurements, 18 pediatric patients (mean 29.5 months; range 1-91 months; 21 examinations) underwent 3.2 high-pitch chest CT on the same DSCT system at 70 kVp tube voltage without any sedation. Radiation dose and presence of motion artifacts was compared to a retrospectively identified patient cohort examined at 80 kVp on a 16-slice single-source-CT (SSCT; n = 15; 14/15 with sedation; mean 30.7 months; range 0-96 months; pitch = 1.5) or on a 2{sup nd} generation DSCT without any sedation (n = 6; mean 32.8 months; range 4-61 months; pitch = 3.2). Radiation dose in the phantom scans was reduced by approximately 40% when using a tube voltage of 70 kVp instead of 80 kVp. In the pediatric patient group examined at 70 kVp age-specific effective dose (ED; mean 0.5 ± 0.2 mSv) was significantly lower when compared to the retrospective cohort scanned at 80 kVp on the 16-slice-SSCT (mean ED: 1.0 ± 0.3 mSv; p < 0.0001) and also considerably lower when compared to the cohort scanned at 80 kVp on the 2{sup nd} generation DSCT (mean ED: 0.9 ± 0.5 mSv). None of the prospective, sedation-free CT examinations showed any motion artifacts whereas 13/15 examinations of the retrospective patient cohort scanned at 80 kVp with a pitch of 1

  15. Single Source 5-dimensional (Space-, Wavelength-, Time-, Polarization-, Quadrature-) 43 Tbit/s Data Transmission of 6 SDM × 6 WDM × 1.2 Tbit/s Nyquist-OTDM-PDM-QPSK

    DEFF Research Database (Denmark)

    Hu, Hao; Ye, Feihong; Medhin, Ashenafi Kiros

    2014-01-01

    We demonstrate 43-Tbit/s transmission over 67.4-km seven-core fiber using a single source. Each of the 6 outer cores carries 6 Nyquist-WDM channels using 320-Gbaud Nyquist- OTDM-PDM-QPSK 330-GHz spaced, and the center core carries 10-GHz clock pulses....

  16. Neuroglial Transmission

    DEFF Research Database (Denmark)

    Gundersen, Vidar; Storm-Mathisen, Jon; Bergersen, Linda Hildegard

    2015-01-01

    as a signaling substance recently shown to act on specific lactate receptors in the brain. Complementing neurotransmission at a synapse, neuroglial transmission often implies diffusion of the transmitter over a longer distance and concurs with the concept of volume transmission. Transmission from glia modulates...... synaptic neurotransmission based on energetic and other local conditions in a volume of tissue surrounding the individual synapse. Neuroglial transmission appears to contribute significantly to brain functions such as memory, as well as to prevalent neuropathologies....

  17. Bender/Coiler for Tubing

    Science.gov (United States)

    Stoltzfus, J. M.

    1983-01-01

    Easy-to-use tool makes coils of tubing. Tubing to be bend clamped with stop post. Die positioned snugly against tubing. Operator turns handle to slide die along tubing, pushing tubing into spiral groove on mandrel.

  18. Diagnostic accuracy of coronary CT angiography using 3{sup rd}-generation dual-source CT and automated tube voltage selection: Clinical application in a non-obese and obese patient population

    Energy Technology Data Exchange (ETDEWEB)

    Mangold, Stefanie [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Eberhard-Karls University Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany); Wichmann, Julian L. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Schoepf, U.J. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Medical University of South Carolina, Division of Cardiology, Department of Medicine, Charleston, SC (United States); Caruso, Damiano [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); University of Rome ' ' Sapienza' ' , Department of Radiological Sciences, Oncology and Pathology, Rome (Italy); Tesche, Christian [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Heart Centre Munich-Bogenhausen, Department of Cardiology, Munich (Germany); Steinberg, Daniel H.; Bayer, Richard R. [Medical University of South Carolina, Division of Cardiology, Department of Medicine, Charleston, SC (United States); Varga-Szemes, Akos; Stubenrauch, Andrew C.; Biancalana, Matthew; De Cecco, Carlo N. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Nikolaou, Konstantin [Eberhard-Karls University Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany)

    2017-06-15

    To investigate diagnostic accuracy of 3{sup rd}-generation dual-source CT (DSCT) coronary angiography in obese and non-obese patients. We retrospectively analyzed 76 patients who underwent coronary CT angiography (CCTA) and invasive coronary angiography. Prospectively ECG-triggered acquisition was performed with automated tube voltage selection (ATVS). Patients were dichotomized based on body mass index in groups A (<30 kg/m{sup 2}, n = 37) and B (≥30 kg/m{sup 2}, n = 39) and based on tube voltage in groups C (<120 kV, n = 46) and D (120 kV, n = 30). Coronary arteries were assessed for significant stenoses (≥50 % luminal narrowing) and diagnostic accuracy was calculated. Per-patient overall sensitivity, specificity, positive predictive value, negative predictive value (NPV) and accuracy were 96.9 %, 95.5 %, 93.9 %, 97.7 % and 96.1 %, respectively. Sensitivity and NPV were lower in groups B and D compared to groups A and C, but no statistically significant differences were observed (group A vs. B: sensitivity, 100.0 % vs. 93.3 %, p = 0.9493; NPV, 100 % vs. 95.5 %, p = 0.9812; group C vs. D: sensitivity, 100.0 % vs. 92.3 %, p = 0.8462; NPV, 100.0 % vs. 94.1 %, p = 0.8285). CCTA using 3{sup rd}-generation DSCT and (ATVS) provides high diagnostic accuracy in both non-obese and obese patients. (orig.)

  19. Diagnostic accuracy of coronary CT angiography using 3"r"d-generation dual-source CT and automated tube voltage selection: Clinical application in a non-obese and obese patient population

    International Nuclear Information System (INIS)

    Mangold, Stefanie; Wichmann, Julian L.; Schoepf, U.J.; Caruso, Damiano; Tesche, Christian; Steinberg, Daniel H.; Bayer, Richard R.; Varga-Szemes, Akos; Stubenrauch, Andrew C.; Biancalana, Matthew; De Cecco, Carlo N.; Nikolaou, Konstantin

    2017-01-01

    To investigate diagnostic accuracy of 3"r"d-generation dual-source CT (DSCT) coronary angiography in obese and non-obese patients. We retrospectively analyzed 76 patients who underwent coronary CT angiography (CCTA) and invasive coronary angiography. Prospectively ECG-triggered acquisition was performed with automated tube voltage selection (ATVS). Patients were dichotomized based on body mass index in groups A (<30 kg/m"2, n = 37) and B (≥30 kg/m"2, n = 39) and based on tube voltage in groups C (<120 kV, n = 46) and D (120 kV, n = 30). Coronary arteries were assessed for significant stenoses (≥50 % luminal narrowing) and diagnostic accuracy was calculated. Per-patient overall sensitivity, specificity, positive predictive value, negative predictive value (NPV) and accuracy were 96.9 %, 95.5 %, 93.9 %, 97.7 % and 96.1 %, respectively. Sensitivity and NPV were lower in groups B and D compared to groups A and C, but no statistically significant differences were observed (group A vs. B: sensitivity, 100.0 % vs. 93.3 %, p = 0.9493; NPV, 100 % vs. 95.5 %, p = 0.9812; group C vs. D: sensitivity, 100.0 % vs. 92.3 %, p = 0.8462; NPV, 100.0 % vs. 94.1 %, p = 0.8285). CCTA using 3"r"d-generation DSCT and (ATVS) provides high diagnostic accuracy in both non-obese and obese patients. (orig.)

  20. Application of low power X-ray tubes in geology

    International Nuclear Information System (INIS)

    Massalski, J.M.; Zaraska, W.

    1981-01-01

    Low power X-ray tubes with transmission anodes for X-ray fluorescence analysis with energy dispersion were elaborated. Paper contains experimental results of application of X-ray tubes in the apparatus for nondestructive measurements of the concentration of some elements in borehole cores. (author)

  1. Scintillation probe with photomultiplier tube saturation indicator

    International Nuclear Information System (INIS)

    Ruch, J.F.; Urban, D.J.

    1996-01-01

    A photomultiplier tube saturation indicator is formed by supplying a supplemental light source, typically an light emitting diode (LED), adjacent to the photomultiplier tube. A switch allows the light source to be activated. The light is forwarded to the photomultiplier tube by an optical fiber. If the probe is properly light tight, then a meter attached to the indicator will register the light from the LED. If the probe is no longer light tight, and the saturation indicator is saturated, no signal will be registered when the LED is activated. 2 figs

  2. Offshore Transmission Technology

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-10-15

    The purpose of this document is to give an overview of offshore electricity transmission technologies. In particular this document is concerned with the use of High Voltage Direct Current (HVDC) systems and more specifically with the development of Voltage Source Converter (VSC) technology. This report outlines the current state of the main technology groups required for offshore HVDC transmission as well as giving examples of offshore projects (both current and future). Finally some indications of likely unit costs for HV assets are given.

  3. Demonstration of L-band DP-QPSK transmission over FSO and fiber channels employing InAs/InP quantum-dash laser source

    KAUST Repository

    Shemis, M.A.; Khan, M.T.A.; Alkhazraji, E.; Ragheb, A.M.; Esmail, M.A.; Fathallah, H.; Qureshi, K.K.; Alshebeili, S.; Khan, M.Z.M.

    2017-01-01

    The next generation of optical access communication networks that support 100 Gbps and beyond, require advances in modulation schemes, spectrum utilization, new transmission bands, and efficient devices, particularly laser diodes. In this paper, we

  4. Transmission issues

    International Nuclear Information System (INIS)

    Bradford, J.; Wilson, L.; Thon, S.; Millar, N.

    2005-01-01

    This session on transmission issues focused on the role that transmission plays in electricity markets and the importance of getting the market structure right in terms of generation divestiture with buy back contracts, demand side responsive programs, transmission upgrades and long term contracts. The difficulties of distinguishing between market power and scarcity were examined along with some of the complications that ensue if transmission experiences congestion, as exemplified by the August 2003 blackout in eastern North America. The presentations described the best ways to handle transmission issues, and debated whether transmission should be deregulated or follow market forces. Issues of interconnections and reliability of connections were also debated along with the attempt to integrate renewables into the grid. Some presentations identified what new transmission must be built and what must be done to ensure that transmission gets built. The challenges and business opportunities for transmission in Alberta were discussed with reference to plans to invest in new infrastructure, where it is going outside of the province and how it works with other jurisdictions. Manitoba's Conawapa Hydro Project and its 2000 MW tie line to Ontario was also discussed. Some examples of non-optimal use of interconnections in Europe were also discussed in an effort to learn from these mistakes and avoid them in Canada. tabs., figs

  5. X-ray tubes

    International Nuclear Information System (INIS)

    Young, R.W.

    1979-01-01

    A form of x-ray tube is described which provides satisfactory focussing of the electron beam when the beam extends for several feet from gun to target. Such a tube can be used for computerised tomographic scanning. (UK)

  6. Pressure tube type reactors

    International Nuclear Information System (INIS)

    Komada, Masaoki.

    1981-01-01

    Purpose: To increase the safety of pressure tube type reactors by providing an additional ECCS system to an ordinary ECCS system and injecting heavy water in the reactor core tank into pressure tubes upon fractures of the tubes. Constitution: Upon fractures of pressure tubes, reduction of the pressure in the fractured tubes to the atmospheric pressure in confirmed and the electromagnetic valve is operated to completely isolate the pressure tubes from the fractured portion. Then, the heavy water in the reactor core tank flows into and spontaneously recycles through the pressure tubes to cool the fuels in the tube to prevent their meltdown. By additionally providing the separate ECCS system to the ordinary ECCS system, fuels can be cooled upon loss of coolant accidents to improve the safety of the reactors. (Moriyama, K.)

  7. Gastrostomy feeding tube - bolus

    Science.gov (United States)

    Feeding - gastrostomy tube - bolus; G-tube - bolus; Gastrostomy button - bolus; Bard Button - bolus; MIC-KEY - bolus ... KEY, 3 to 8 weeks after surgery. These feedings will help your child grow strong and healthy. ...

  8. Feeding tube insertion - gastrostomy

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/002937.htm Feeding tube insertion - gastrostomy To use the sharing features on this page, please enable JavaScript. A gastrostomy feeding tube insertion is the placement of a feeding ...

  9. Neural Tube Defects

    Science.gov (United States)

    Neural tube defects are birth defects of the brain, spine, or spinal cord. They happen in the ... that she is pregnant. The two most common neural tube defects are spina bifida and anencephaly. In ...

  10. Transmission positron microscopes

    International Nuclear Information System (INIS)

    Doyama, Masao; Kogure, Yoshiaki; Inoue, Miyoshi; Kurihara, Toshikazu; Yoshiie, Toshimasa; Oshima, Ryuichiro; Matsuya, Miyuki

    2006-01-01

    Immediate and near-future plans for transmission positron microscopes being built at KEK, Tsukuba, Japan, are described. The characteristic feature of this project is remolding a commercial electron microscope to a positron microscope. A point source of electrons kept at a negative high voltage is changed to a point source of positrons kept at a high positive voltage. Positional resolution of transmission microscopes should be theoretically the same as electron microscopes. Positron microscopes utilizing trapping of positrons have always positional ambiguity due to the diffusion of positrons

  11. Transmission eigenvalues

    Science.gov (United States)

    Cakoni, Fioralba; Haddar, Houssem

    2013-10-01

    In inverse scattering theory, transmission eigenvalues can be seen as the extension of the notion of resonant frequencies for impenetrable objects to the case of penetrable dielectrics. The transmission eigenvalue problem is a relatively late arrival to the spectral theory of partial differential equations. Its first appearance was in 1986 in a paper by Kirsch who was investigating the denseness of far-field patterns for scattering solutions of the Helmholtz equation or, in more modern terminology, the injectivity of the far-field operator [1]. The paper of Kirsch was soon followed by a more systematic study by Colton and Monk in the context of developing the dual space method for solving the inverse scattering problem for acoustic waves in an inhomogeneous medium [2]. In this paper they showed that for a spherically stratified media transmission eigenvalues existed and formed a discrete set. Numerical examples were also given showing that in principle transmission eigenvalues could be determined from the far-field data. This first period of interest in transmission eigenvalues was concluded with papers by Colton et al in 1989 [3] and Rynne and Sleeman in 1991 [4] showing that for an inhomogeneous medium (not necessarily spherically stratified) transmission eigenvalues, if they existed, formed a discrete set. For the next seventeen years transmission eigenvalues were ignored. This was mainly due to the fact that, with the introduction of various sampling methods to determine the shape of an inhomogeneous medium from far-field data, transmission eigenvalues were something to be avoided and hence the fact that transmission eigenvalues formed at most a discrete set was deemed to be sufficient. In addition, questions related to the existence of transmission eigenvalues or the structure of associated eigenvectors were recognized as being particularly difficult due to the nonlinearity of the eigenvalue problem and the special structure of the associated transmission

  12. Third-generation dual-source CT of the neck using automated tube voltage adaptation in combination with advanced modeled iterative reconstruction: evaluation of image quality and radiation dose

    International Nuclear Information System (INIS)

    Scholtz, Jan-Erik; Wichmann, Julian L.; Huesers, Kristina; Albrecht, Moritz H.; Beeres, Martin; Bauer, Ralf W.; Vogl, Thomas J.; Bodelle, Boris

    2016-01-01

    To evaluate image quality and radiation dose in third-generation dual-source computed tomography (DSCT) of the neck using automated tube voltage adaptation (TVA) with advanced modelled iterative reconstruction (ADMIRE) algorithm. One hundred and sixteen patients were retrospectively evaluated. Group A (n = 59) was examined on second-generation DSCT with automated TVA and filtered back projection. Group B (n = 57) was examined on a third-generation DSCT with automated TVA and ADMIRE. Age, body diameter, attenuation of several anatomic structures, noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), radiation dose (CTDI vol ) and size-specific dose estimates (SSDE) were assessed. Diagnostic acceptability was rated by three readers. Age (p = 0.87) and body diameter (p = 0.075) did not differ significantly. Tube voltage in Group A was set automatically to 100 kV for all patients (n = 59), and to 70 kV (n = 2), 80 kV (n = 5), and 90 kV (n = 50) in Group B. Noise was reduced and CNR was increased significantly (p < 0.001). Diagnostic acceptability was rated high in both groups, with better ratings in Group B (p < 0.001). SSDE was reduced by 34 % in Group B (20.38 ± 1.63 mGy vs. 13.04 ± 1.50 mGy, p < 0.001). Combination of automated TVA and ADMIRE in neck CT using third-generation DSCT results in a substantial radiation dose reduction with low noise and increased CNR. (orig.)

  13. Effect of automated tube voltage selection, integrated circuit detector and advanced iterative reconstruction on radiation dose and image quality of 3rd generation dual-source aortic CT angiography: An intra-individual comparison.

    Science.gov (United States)

    Mangold, Stefanie; De Cecco, Carlo N; Wichmann, Julian L; Canstein, Christian; Varga-Szemes, Akos; Caruso, Damiano; Fuller, Stephen R; Bamberg, Fabian; Nikolaou, Konstantin; Schoepf, U Joseph

    2016-05-01

    To compare, on an intra-individual basis, the effect of automated tube voltage selection (ATVS), integrated circuit detector and advanced iterative reconstruction on radiation dose and image quality of aortic CTA studies using 2nd and 3rd generation dual-source CT (DSCT). We retrospectively evaluated 32 patients who had undergone CTA of the entire aorta with both 2nd generation DSCT at 120kV using filtered back projection (FBP) (protocol 1) and 3rd generation DSCT using ATVS, an integrated circuit detector and advanced iterative reconstruction (protocol 2). Contrast-to-noise ratio (CNR) was calculated. Image quality was subjectively evaluated using a five-point scale. Radiation dose parameters were recorded. All studies were considered of diagnostic image quality. CNR was significantly higher with protocol 2 (15.0±5.2 vs 11.0±4.2; p<.0001). Subjective image quality analysis revealed no significant differences for evaluation of attenuation (p=0.08501) but image noise was rated significantly lower with protocol 2 (p=0.0005). Mean tube voltage and effective dose were 94.7±14.1kV and 6.7±3.9mSv with protocol 2; 120±0kV and 11.5±5.2mSv with protocol 1 (p<0.0001, respectively). Aortic CTA performed with 3rd generation DSCT, ATVS, integrated circuit detector, and advanced iterative reconstruction allow a substantial reduction of radiation exposure while improving image quality in comparison to 120kV imaging with FBP. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  14. A Statistical Framework for Microbial Source Attribution: Measuring Uncertainty in Host Transmission Events Inferred from Genetic Data (Part 2 of a 2 Part Report)

    Energy Technology Data Exchange (ETDEWEB)

    Allen, J; Velsko, S

    2009-11-16

    This report explores the question of whether meaningful conclusions can be drawn regarding the transmission relationship between two microbial samples on the basis of differences observed between the two sample's respective genomes. Unlike similar forensic applications using human DNA, the rapid rate of microbial genome evolution combined with the dynamics of infectious disease require a shift in thinking on what it means for two samples to 'match' in support of a forensic hypothesis. Previous outbreaks for SARS-CoV, FMDV and HIV were examined to investigate the question of how microbial sequence data can be used to draw inferences that link two infected individuals by direct transmission. The results are counter intuitive with respect to human DNA forensic applications in that some genetic change rather than exact matching improve confidence in inferring direct transmission links, however, too much genetic change poses challenges, which can weaken confidence in inferred links. High rates of infection coupled with relatively weak selective pressure observed in the SARS-CoV and FMDV data lead to fairly low confidence for direct transmission links. Confidence values for forensic hypotheses increased when testing for the possibility that samples are separated by at most a few intermediate hosts. Moreover, the observed outbreak conditions support the potential to provide high confidence values for hypothesis that exclude direct transmission links. Transmission inferences are based on the total number of observed or inferred genetic changes separating two sequences rather than uniquely weighing the importance of any one genetic mismatch. Thus, inferences are surprisingly robust in the presence of sequencing errors provided the error rates are randomly distributed across all samples in the reference outbreak database and the novel sequence samples in question. When the number of observed nucleotide mutations are limited due to characteristics of the

  15. 21 CFR 868.5800 - Tracheostomy tube and tube cuff.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tracheostomy tube and tube cuff. 868.5800 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5800 Tracheostomy tube and tube cuff. (a) Identification. A tracheostomy tube and tube cuff is a device intended to be placed into a...

  16. Neutron source

    International Nuclear Information System (INIS)

    Cason, J.L. Jr.; Shaw, C.B.

    1975-01-01

    A neutron source which is particularly useful for neutron radiography consists of a vessel containing a moderating media of relatively low moderating ratio, a flux trap including a moderating media of relatively high moderating ratio at the center of the vessel, a shell of depleted uranium dioxide surrounding the moderating media of relatively high moderating ratio, a plurality of guide tubes each containing a movable source of neutrons surrounding the flux trap, a neutron shield surrounding one part of each guide tube, and at least one collimator extending from the flux trap to the exterior of the neutron source. The shell of depleted uranium dioxide has a window provided with depleted uranium dioxide shutters for each collimator. Reflectors are provided above and below the flux trap and on the guide tubes away from the flux trap

  17. Heat exchanger tube tool

    International Nuclear Information System (INIS)

    Gugel, G.

    1976-01-01

    Certain types of heat-exchangers have tubes opening through a tube sheet to a manifold having an access opening offset from alignment with the tube ends. A tool for inserting a device, such as for inspection or repair, is provided for use in such instances. The tool is formed by a flexible guide tube insertable through the access opening and having an inner end provided with a connector for connection with the opening of the tube in which the device is to be inserted, and an outer end which remains outside of the chamber, the guide tube having adequate length for this arrangement. A flexible transport hose for internally transporting the device slides inside of the guide tube. This hose is long enough to slide through the guide tube, into the heat-exchanger tube, and through the latter to the extent required for the use of the device. The guide tube must be bent to reach the end of the heat-exchanger tube and the latter may be constructed with a bend, the hose carrying anit-friction elements at interspaced locations along its length to make it possible for the hose to negotiate such bends while sliding to the location where the use of the device is required

  18. Failure analysis of retired steam generator tubings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hong Pyo; Kim, J. S.; Hwang, S. S. and others

    2005-04-15

    Degradation of steam generator leads to forced outage and extension of outage, which causes increase in repair cost, cost of purchasing replacement power and radiation exposure of workers. Steam generator tube rupture incident occurred in Uljin 4 in 2002, which made public sensitive to nuclear power plant. To keep nuclear energy as a main energy source, integrity of steam generator should be demonstrated. Quantitative relationship between ECT(eddy current test) signal and crack size is needed in assesment of integrity of steam generator in pressurized water reactor. However, it is not fully established for application in industry. Retired steam generator of Kori 1 has many kinds of crack such as circumferential and axial primary water stress corrosion crack and outer diameter stress corrosion crack(ODSCC). So, it can be used in qualifying and improving ECT technology and in condition monitoring assesment for crack detected in ISI(in service inspection). In addition, examination of pulled tube of Kori 1 retired steam generator will give information about effectiveness of non welded sleeving technology which was employed to repair defect tubes and remedial action which was applied to mitigate ODSCC. In this project, hardware such as semi hot lab. for pulled tube examination and modification transportation cask for pulled tube and software such as procedure of transportation of radioactive steam generator tube and non-destructive and destructive examination of pulled tube were established. Non-destructive and destructive examination of pulled tubes from Kori 1 retired steam generator were performed in semi hot lab. Remedial actions applied to Kori 1 retired steam generator, PWSCC trend and bulk water chemistry and crevice chemistry in Kori 1 were evaluated. Electrochemical decontamination technology for pulled tube was developed to reduce radiation exposure and enhance effectiveness of pulled tube examination. Multiparameter algorithm developed at ANL, USA was

  19. Intercostal drainage tube or intracardiac drainage tube?

    Directory of Open Access Journals (Sweden)

    N Anitha

    2016-01-01

    Full Text Available Although insertion of chest drain tubes is a common medical practice, there are risks associated with this procedure, especially when inexperienced physicians perform it. Wrong insertion of the tube has been known to cause morbidity and occasional mortality. We report a case where the left ventricle was accidentally punctured leading to near-exsanguination. This report is to highlight the need for experienced physicians to supervise the procedure and train the younger physician in the safe performance of the procedure.

  20. Intercostal drainage tube or intracardiac drainage tube?

    Science.gov (United States)

    Anitha, N; Kamath, S Ganesh; Khymdeit, Edison; Prabhu, Manjunath

    2016-01-01

    Although insertion of chest drain tubes is a common medical practice, there are risks associated with this procedure, especially when inexperienced physicians perform it. Wrong insertion of the tube has been known to cause morbidity and occasional mortality. We report a case where the left ventricle was accidentally punctured leading to near-exsanguination. This report is to highlight the need for experienced physicians to supervise the procedure and train the younger physician in the safe performance of the procedure.

  1. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... YouTube Videos » NEI YouTube Videos: Amblyopia Listen NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration ... Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded video for NEI YouTube Videos: ...

  2. Force transmissibility versus displacement transmissibility

    Science.gov (United States)

    Lage, Y. E.; Neves, M. M.; Maia, N. M. M.; Tcherniak, D.

    2014-10-01

    It is well-known that when a single-degree-of-freedom (sdof) system is excited by a continuous motion of the foundation, the force transmissibility, relating the force transmitted to the foundation to the applied force, equals the displacement transmissibility. Recent developments in the generalization of the transmissibility to multiple-degree-of-freedom (mdof) systems have shown that similar simple and direct relations between both types of transmissibility do not appear naturally from the definitions, as happens in the sdof case. In this paper, the authors present their studies on the conditions under which it is possible to establish a relation between force transmissibility and displacement transmissibility for mdof systems. As far as the authors are aware, such a relation is not currently found in the literature, which is justified by being based on recent developments in the transmissibility concept for mdof systems. Indeed, it does not appear naturally, but the authors observed that the needed link is present when the displacement transmissibility is obtained between the same coordinates where the applied and reaction forces are considered in the force transmissibility case; this implies that the boundary conditions are not exactly the same and instead follow some rules. This work presents a formal derivation of the explicit relation between the force and displacement transmissibilities for mdof systems, and discusses its potential and limitations. The authors show that it is possible to obtain the displacement transmissibility from measured forces, and the force transmissibility from measured displacements, opening new perspectives, for example, in the identification of applied or transmitted forces. With this novel relation, it becomes possible, for example, to estimate the force transmissibility matrix with the structure off its supports, in free boundary conditions, and without measuring the forces. As far as force identification is concerned, this

  3. Self-assembling segmented coiled tubing

    Science.gov (United States)

    Raymond, David W.

    2016-09-27

    Self-assembling segmented coiled tubing is a concept that allows the strength of thick-wall rigid pipe, and the flexibility of thin-wall tubing, to be realized in a single design. The primary use is for a drillstring tubular, but it has potential for other applications requiring transmission of mechanical loads (forces and torques) through an initially coiled tubular. The concept uses a spring-loaded spherical `ball-and-socket` type joint to interconnect two or more short, rigid segments of pipe. Use of an optional snap ring allows the joint to be permanently made, in a `self-assembling` manner.

  4. Photomultiplier tubes for Low Level Cerenkov Detectors

    International Nuclear Information System (INIS)

    Strindehag, O.

    1965-03-01

    Tube backgrounds of several 2-inch photomultiplier types having S11, 'S' , S13 and S20 cathodes are compared by measuring signal and background pulse height distributions at pulse heights corresponding to a few photo-electrons. The reference signal is generated by means of a β-source and a plexiglass radiator. It is found that comparatively good results are obtained with selected tubes of the EMI types 6097B and 9514B having equivalent dark current dc values down to 10 -12 input lumens. Special interest is devoted to the correlation between the measured tube backgrounds and the dark current dc values of the tubes, as a good correlation between these parameters simplifies the selection of photomultiplier tubes. The equivalent dark currents of the tested tubes extend over the range 10 -12 to 10 -9 input lumens. Although the investigation deals with photomultiplier tubes intended for use in low level Cerenkov detectors it is believed that the results could be valuable in other fields where photomultiplier tubes are utilized for the detection of weak light pulses

  5. Photomultiplier tubes for Low Level Cerenkov Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Strindehag, O

    1965-03-15

    Tube backgrounds of several 2-inch photomultiplier types having S11, 'S' , S13 and S20 cathodes are compared by measuring signal and background pulse height distributions at pulse heights corresponding to a few photo-electrons. The reference signal is generated by means of a {beta}-source and a plexiglass radiator. It is found that comparatively good results are obtained with selected tubes of the EMI types 6097B and 9514B having equivalent dark current dc values down to 10{sup -12} input lumens. Special interest is devoted to the correlation between the measured tube backgrounds and the dark current dc values of the tubes, as a good correlation between these parameters simplifies the selection of photomultiplier tubes. The equivalent dark currents of the tested tubes extend over the range 10{sup -12} to 10{sup -9} input lumens. Although the investigation deals with photomultiplier tubes intended for use in low level Cerenkov detectors it is believed that the results could be valuable in other fields where photomultiplier tubes are utilized for the detection of weak light pulses.

  6. Demonstration of L-band DP-QPSK transmission over FSO and fiber channels employing InAs/InP quantum-dash laser source

    KAUST Repository

    Shemis, M.A.

    2017-11-23

    The next generation of optical access communication networks that support 100 Gbps and beyond, require advances in modulation schemes, spectrum utilization, new transmission bands, and efficient devices, particularly laser diodes. In this paper, we investigated the viability of new-class of InAs/InP Quantum-dash laser diode (Qdash-LD) exhibiting multiple longitudinal light modes in the L-band to carry high-speed data rate for access network applications. We exploited external and self injection-locking techniques on Qdash-LD to generate large number of stable and tunable locked modes, and compared them. To stem the capability of each locked mode as a potential subcarrier, data transmission is carried out over two mediums; single mode fiber (SMF) and free space optics (FSO) to emulate real deployment scenarios of optical networks. The results showed that with external-injection locking (EIL), an error-free transmission of 100 Gbps dual polarization quadrature phase shift keying (DP-QPSK) signal is demonstrated over 10 km SMF and 4 m indoor FSO channels, with capability of reaching up to 128 Gbps, demonstrated under back-to-back (BTB) configuration. On the other hand, using self-injection locking (SIL) scheme, a successful data transmission of 64 Gbps and 128 Gbps DP-QPSK signal over 20 km SMF and 10 m indoor FSO links, respectively, is achieved.

  7. Demonstration of L-band DP-QPSK transmission over FSO and fiber channels employing InAs/InP quantum-dash laser source

    Science.gov (United States)

    Shemis, M. A.; Khan, M. T. A.; Alkhazraji, E.; Ragheb, A. M.; Esmail, M. A.; Fathallah, H.; Qureshi, K. K.; Alshebeili, S.; Khan, M. Z. M.

    2018-03-01

    The next generation of optical access communication networks that support 100 Gbps and beyond, require advances in modulation schemes, spectrum utilization, new transmission bands, and efficient devices, particularly laser diodes. In this paper, we investigated the viability of new-class of InAs/InP Quantum-dash laser diode (Qdash-LD) exhibiting multiple longitudinal light modes in the L-band to carry high-speed data rate for access network applications. We exploited external and self injection-locking techniques on Qdash-LD to generate large number of stable and tunable locked modes, and compared them. To stem the capability of each locked mode as a potential subcarrier, data transmission is carried out over two mediums; single mode fiber (SMF) and free space optics (FSO) to emulate real deployment scenarios of optical networks. The results showed that with external-injection locking (EIL), an error-free transmission of 100 Gbps dual polarization quadrature phase shift keying (DP-QPSK) signal is demonstrated over 10 km SMF and 4 m indoor FSO channels, with capability of reaching up to 128 Gbps, demonstrated under back-to-back (BTB) configuration. On the other hand, using self-injection locking (SIL) scheme, a successful data transmission of 64 Gbps and 128 Gbps DP-QPSK signal over 20 km SMF and 10 m indoor FSO links, respectively, is achieved.

  8. Data transmission

    National Research Council Canada - National Science Library

    Tugal, Dogan A; Tugal, Osman

    1989-01-01

    This updated second edition provides working answers to today's critical questions about designing and managing all types of data transmission systems and features a new chapter on local area networks (LANs...

  9. Pediatric cuffed endotracheal tubes

    Directory of Open Access Journals (Sweden)

    Neerja Bhardwaj

    2013-01-01

    Full Text Available Endotracheal intubation in children is usually performed utilizing uncuffed endotracheal tubes for conduct of anesthesia as well as for prolonged ventilation in critical care units. However, uncuffed tubes may require multiple changes to avoid excessive air leak, with subsequent environmental pollution making the technique uneconomical. In addition, monitoring of ventilatory parameters, exhaled volumes, and end-expiratory gases may be unreliable. All these problems can be avoided by use of cuffed endotracheal tubes. Besides, cuffed endotracheal tubes may be of advantage in special situations like laparoscopic surgery and in surgical conditions at risk of aspiration. Magnetic resonance imaging (MRI scans in children have found the narrowest portion of larynx at rima glottides. Cuffed endotracheal tubes, therefore, will form a complete seal with low cuff pressure of <15 cm H 2 O without any increase in airway complications. Till recently, the use of cuffed endotracheal tubes was limited by variations in the tube design marketed by different manufacturers. The introduction of a new cuffed endotracheal tube in the market with improved tracheal sealing characteristics may encourage increased safe use of these tubes in clinical practice. A literature search using search words "cuffed endotracheal tube" and "children" from 1980 to January 2012 in PUBMED was conducted. Based on the search, the advantages and potential benefits of cuffed ETT are reviewed in this article.

  10. Disinfection of Biofilms in Tubes with Ultraviolet Light

    DEFF Research Database (Denmark)

    Bak, Jimmy; Begovic, Tanja

    2009-01-01

    Bacterial biofilms on long-term catheters are a major source of infection. We demonstrate here the potential of UVC light emitting diodes (LED) for disinfection purposes in catheter like tubes contaminated with biofilm. We show that UVC Light propagation is possible through teflon tubes using...... to a flow system and biofilms were produced during a three day period. Tubes in lengths of 10 cm (FEP teflon) were contaminated. Tubes for control and for UVC treatment were contaminated in parallel. The control and UVC treated tubes were both filled with a 20 % NaCl solution during the UVC treatment time...

  11. Lunar Lava Tube Sensing

    Science.gov (United States)

    York, Cheryl Lynn; Walden, Bryce; Billings, Thomas L.; Reeder, P. Douglas

    1992-01-01

    Large (greater than 300 m diameter) lava tube caverns appear to exist on the Moon and could provide substantial safety and cost benefits for lunar bases. Over 40 m of basalt and regolith constitute the lava tube roof and would protect both construction and operations. Constant temperatures of -20 C reduce thermal stress on structures and machines. Base designs need not incorporate heavy shielding, so lightweight materials can be used and construction can be expedited. Identification and characterization of lava tube caverns can be incorporated into current precursor lunar mission plans. Some searches can even be done from Earth. Specific recommendations for lunar lava tube search and exploration are (1) an Earth-based radar interferometer, (2) an Earth-penetrating radar (EPR) orbiter, (3) kinetic penetrators for lunar lava tube confirmation, (4) a 'Moon Bat' hovering rocket vehicle, and (5) the use of other proposed landers and orbiters to help find lunar lava tubes.

  12. Categorising YouTube

    DEFF Research Database (Denmark)

    Simonsen, Thomas Mosebo

    2011-01-01

    This article provides a genre analytical approach to creating a typology of the User Generated Content (UGC) of YouTube. The article investigates the construction of navigation processes on the YouTube website. It suggests a pragmatic genre approach that is expanded through a focus on YouTube......’s technological affordances. Through an analysis of the different pragmatic contexts of YouTube, it is argued that a taxonomic understanding of YouTube must be analysed in regards to the vacillation of a user-driven bottom-up folksonomy and a hierarchical browsing system that emphasises a culture of competition...... and which favours the already popular content of YouTube. With this taxonomic approach, the UGC videos are registered and analysed in terms of empirically based observations. The article identifies various UGC categories and their principal characteristics. Furthermore, general tendencies of the UGC within...

  13. Steam generator tube performance

    International Nuclear Information System (INIS)

    Tatone, O.S.; Pathania, R.S.

    1983-08-01

    A review of the performance of steam generator tubes in 110 water-cooled nuclear power reactors showed that tubes were plugged at 46 (42 percent) of the reactors. The number of tubes removed from service increased from 1900 (0.14 percent) in 1980 to 4692 (0.30 percent) in 1981. The leading causes of tube failures were stress corrosion cracking from the primary side, stress corrosion cracking (or intergranular attack) from the secondary side and pitting corrosion. The lowest incidence of corrosion-induced defects from the secondary side occurred in reactors that used all-volatile treatment since start-up. At one reactor a large number of degraded tubes were repaired by sleeving which is expected to become an important method of tube repair in the future

  14. Detection, prevalence, and transmission of avian hematozoa in waterfowl at the Arctic/sub-Arctic interface: co-infections, viral interactions, and sources of variation.

    Science.gov (United States)

    Meixell, Brandt; Arnold, Todd W.; Lindberg, Mark S.; Smith, Matthew M.; Runstadler, Jonathan A.; Ramey, Andy M.

    2016-01-01

    Background: The epidemiology of avian hematozoa at high latitudes is still not well understood, particularly in sub-Arctic and Arctic habitats, where information is limited regarding seasonality and range of transmission, co-infection dynamics with parasitic and viral agents, and possible fitness consequences of infection. Such information is important as climate warming may lead to northward expansion of hematozoa with unknown consequences to northern-breeding avian taxa, particularly populations that may be previously unexposed to blood parasites.

  15. Rectangular drift tube characteristics

    International Nuclear Information System (INIS)

    Denisov, D.S.; Musienko, Yu.V.

    1985-01-01

    Results on the study of the characteristics of a 50 x 100 mm aluminium drift tube are presented. The tube was filled with argon-methane and argon-isobutane mixtures. With 16 per cent methane concentration the largest deviation from a linear relation between the drift time and the drift path over 50 mm is less than 2 mm. The tube filled with argon-isobutane mixture is capable of operating in a limited streamer mode

  16. Schizophrenia on YouTube.

    Science.gov (United States)

    Nour, Matthew M; Nour, Murraih H; Tsatalou, Olga-Maria; Barrera, Alvaro

    2017-01-01

    YouTube ( www.youtube.com ) is the most popular video-sharing Web site on the Internet and is used by medical students as a source of information regarding mental health conditions, including schizophrenia. The accuracy and educational utility of schizophrenia presentations on YouTube are unknown. The purpose of this study was to analyze the accuracy of depictions of psychosis in the context of a diagnosis of schizophrenia (referred to in this article as "acute schizophrenia") on YouTube and to assess the utility of these videos as educational tools for teaching medical students to recognize the clinical features of acute schizophrenia. YouTube was searched for videos purporting to show acute schizophrenia. Eligible videos were independently rated by two consultant psychiatrists on two separate occasions 22 days apart for diagnostic accuracy, psychopathology, and educational utility. Videos (N=4,200) were assessed against predefined inclusion and exclusion criteria. The majority were not eligible for further analysis, mostly because they did not claim to show a patient with schizophrenia (74%) or contained duplicated content (11%). Of 35 videos that met the eligibility and adequacy criteria, only 12 accurately depicted acute schizophrenia. Accurate videos were characterized by persecutory delusions (83%), inappropriate affect (75%), and negative symptoms (83%). Despite the fact that 83% of accurate videos were deemed to have good educational utility compared with 15% of inaccurate videos, accurate and inaccurate videos had similar view counts (290,048 versus 186,124). Schizophrenia presentations on YouTube offer a distorted picture of the condition.

  17. Categorising YouTube

    OpenAIRE

    Simonsen, Thomas Mosebo

    2011-01-01

    This article provides a genre analytical approach to creating a typology of the User Generated Content (UGC) of YouTube. The article investigates the construction of navigation processes on the YouTube website. It suggests a pragmatic genre approach that is expanded through a focus on YouTube’s technological affordances. Through an analysis of the different pragmatic contexts of YouTube, it is argued that a taxonomic understanding of YouTube must be analysed in regards to the vacillation of a...

  18. Pressure tube reactor

    International Nuclear Information System (INIS)

    Susuki, Akira; Murata, Shigeto; Minato, Akihiko.

    1993-01-01

    In a pressure tube reactor, a reactor core is constituted by arranging more than two units of a minimum unit combination of a moderator sealing pipe containing a calandria tube having moderators there between and a calandria tube and moderators. The upper header and a lower header of the calandria tank containing moderators are communicated by way of the moderator sealing tube. Further, a gravitationally dropping mechanism is disposed for injecting neutron absorbing liquid to a calandria gas injection portion. A ratio between a moderator volume and a fuel volume is defined as a function of the inner diameter of the moderator sealing tube, the outer diameter of the calandria tube and the diameter of fuel pellets, and has no influence to intervals of a pressure tube lattice. The interval of the pressure tube lattice is enlarged without increasing the size of the pressure tube, to improve production efficiency of the reactor and set a coolant void coefficient more negative, thereby enabling to improve self controllability and safety. Further, the reactor scram can be conducted by injecting neutron absorbing liquid. (N.H.)

  19. Heated Tube Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Heated Tube Facility at NASA GRC investigates cooling issues by simulating conditions characteristic of rocket engine thrust chambers and high speed airbreathing...

  20. Steam generator tube performance

    International Nuclear Information System (INIS)

    Tatone, O.S.; Pathania, R.S.

    1984-10-01

    A review of the performance of steam generator tubes in 116 water-cooled nuclear power reactors showed that tubes were plugged at 54 (46 percent) of the reactors. The number of tubes removed from service decreased from 4 692 (0.30 percent) in 1981 to 3 222 (0.20 percent) in 1982. The leading causes of tube failures were stress corrosion cracking from the primary side, stress corrosion cracking (or intergranular attack) from the secondary side and pitting corrosion. The lowest incidence of corrosion-induced defects from the secondary side occurred in reactors that have used only volatile treatment, with or without condensate demineralization

  1. Steam generator tube performance

    International Nuclear Information System (INIS)

    Tatone, O.S.; Tapping, R.L.; Stipan, L.

    1992-03-01

    A survey of steam generator operating experience for 1986 has been carried out for 184 pressurized water and pressurized heavy-water reactors, and 1 water-cooled, graphite-moderated reactor. Tubes were plugged at 75 of the reactors (40.5%). In 1986, 3737 tubes were plugged (0.14% of those in service) and 3148 tubes were repaired by sleeving. A small number of reactors accounted for the bulk of the plugged tubes, a phenomenon consistent with previous years. For 1986, the available tubesheet sludge data for 38 reactors has been compiled into tabular form, and sludge/deposit data will be incorporated into all future surveys

  2. Influence of tube spinning on formability of friction stir welded aluminum alloy tubes for hydroforming application

    Energy Technology Data Exchange (ETDEWEB)

    Wang, X.S. [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Hu, Z.L., E-mail: zhilihuhit@163.com [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Hubei Key Laboratory of Advanced Technology of Automobile Parts, Wuhan University of Technology, Wuhan 430070 (China); State Key Laboratory of Materials Processing and Die and Mould Technology, Huazhong University of Science and Technology (China); Yuan, S.J. [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Hua, L. [Hubei Key Laboratory of Advanced Technology of Automobile Parts, Wuhan University of Technology, Wuhan 430070 (China)

    2014-06-01

    Due to economic and ecological reasons, the application of tailor-welded blanks of aluminum alloy has gained more and more attention in manufacturing lightweight structures for automotives and aircrafts. In the study, the research was aimed to highlight the influence of spinning on the formability of FSW tubes. The microstructural characteristics of the FSW tubes during spinning were studied by electron backscattered diffraction (EBSD) and transmission electron microscopy (TEM). The formability of the FSW tubes with different spinning reduction was assessed by hydraulic bulge test. It is found that the spinning process shows a grain refinement of the tube. The grains of the FSW tube decrease with increasing thickness reduction, and the effect of grain refinement is more obvious for the BM compared to that of the weld. The difference of grain size and precipitates between the weld and BM leads to an asymmetric W-type microhardness distribution after spinning. The higher thickness reduction of the tube, the more uniform distribution of grains and precipitates it shows, and consequently results in more significant increase of strength. As compared with the result of tensile test, the tube after spinning shows better formability when the stress state changes from uniaxial to biaxial stress state.

  3. Electrical transmission

    Energy Technology Data Exchange (ETDEWEB)

    Sayers, D P

    1960-05-01

    After briefly tracing the history of electricity transmission, trends in high voltage transmission and experiments being conducted on 650 kV are discussed. 5000 miles of the U.K. grid are operated at 132 kV and 1000 at 275 kV, ultimately to provide a super grid at 380 kV. Problems are insulation, radio interference and the cost of underground lines (16 times that of overhead lines). Also considered are the economics of the grid as a means of transporting energy and as a means of spreading the peak load over the power stations in the most efficient manner. Finally, the question of amenities is discussed.

  4. Steam generator tube failures

    International Nuclear Information System (INIS)

    MacDonald, P.E.; Shah, V.N.; Ward, L.W.; Ellison, P.G.

    1996-04-01

    A review and summary of the available information on steam generator tubing failures and the impact of these failures on plant safety is presented. The following topics are covered: pressurized water reactor (PWR), Canadian deuterium uranium (CANDU) reactor, and Russian water moderated, water cooled energy reactor (VVER) steam generator degradation, PWR steam generator tube ruptures, the thermal-hydraulic response of a PWR plant with a faulted steam generator, the risk significance of steam generator tube rupture accidents, tubing inspection requirements and fitness-for-service criteria in various countries, and defect detection reliability and sizing accuracy. A significant number of steam generator tubes are defective and are removed from service or repaired each year. This wide spread damage has been caused by many diverse degradation mechanisms, some of which are difficult to detect and predict. In addition, spontaneous tube ruptures have occurred at the rate of about one every 2 years over the last 20 years, and incipient tube ruptures (tube failures usually identified with leak detection monitors just before rupture) have been occurring at the rate of about one per year. These ruptures have caused complex plant transients which have not always been easy for the reactor operators to control. Our analysis shows that if more than 15 tubes rupture during a main steam line break, the system response could lead to core melting. Although spontaneous and induced steam generator tube ruptures are small contributors to the total core damage frequency calculated in probabilistic risk assessments, they are risk significant because the radionuclides are likely to bypass the reactor containment building. The frequency of steam generator tube ruptures can be significantly reduced through appropriate and timely inspections and repairs or removal from service

  5. Method for shaping polyethylene tubing

    Science.gov (United States)

    Kramer, R. C.

    1981-01-01

    Method forms polyethylene plastic tubing into configurations previously only possible with metal tubing. By using polyethylene in place of copper or stain less steel tubing inlow pressure systems, fabrication costs are significantly reduced. Polyethylene tubing can be used whenever low pressure tubing is needed in oil operations, aircraft and space applications, powerplants, and testing laboratories.

  6. Pyrotechnic Tubing Connector

    Science.gov (United States)

    Graves, Thomas J.; Yang, Robert A.

    1988-01-01

    Tool forms mechanical seal at joint without levers or hydraulic apparatus. Proposed tool intended for use in outer space used on Earth by heavily garbed workers to join tubing in difficult environments. Called Pyrotool, used with Lokring (or equivalent) fittings. Piston slides in cylinder when pushed by gas from detonating pyrotechnic charge. Impulse of piston compresses fittings, sealing around butting ends of tubes.

  7. Building lab-scale x-ray tube based irradiators

    International Nuclear Information System (INIS)

    Haff, Ron; Jackson, Eric; Gomez, Joseph; Light, Doug; Follett, Peter; Simmons, Greg; Higbee, Brad

    2016-01-01

    Here we report the use of x-ray tube based irradiators as alternatives to gamma sources for laboratory scale irradiation. Irradiators were designed with sample placement in closest possible proximity to the source, allowing high dose rates for small samples. Designs using 1000 W x-ray tubes in single tube, double tube, and four tube configurations are described, as well as various cabinet construction techniques. Relatively high dose rates were achieved for small samples, demonstrating feasibility for laboratory based irradiators for research purposes. Dose rates of 9.76, 5.45, and 1.7 Gy/min/tube were measured at the center of a 12.7 cm container of instant rice at 100 keV, 70 keV, and 40 keV, respectively. Dose uniformity varies dramatically as the distance from source to container. For 2.54 cm diameter sample containers containing adult Navel Orangeworm, dose rates of 50–60 Gy/min were measured in the four tube system. - Highlights: • X-ray is demonstrated as an alternative to gamma for lab-based irradiation. • Cabinets using one, two, and four 1000 W tubes are reported. • Dose rate of 9.8 Gy/min/tube at the center of a 12.7 cm container of instant rice. • Dose uniformity varies dramatically as the distance from source to container.

  8. Molybdenum Tube Characterization report

    Energy Technology Data Exchange (ETDEWEB)

    Beaux II, Miles Frank [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Usov, Igor Olegovich [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-07

    Chemical vapor deposition (CVD) techniques have been utilized to produce free-standing molybdenum tubes with the end goal of nuclear fuel clad applications. In order to produce tubes with properties desirable for this application, deposition rates were lowered requiring long deposition durations on the order of 50 hours. Standard CVD methods as well as fluidized-bed CVD (FBCVD) methods were applied towards these objectives. Characterization of the tubes produced in this manner revealed material suitable for fuel clad applications, but lacking necessary uniformity across the length of the tubes. The production of freestanding Mo tubes that possess the desired properties across their entire length represents an engineering challenge that can be overcome in a next iteration of the deposition system.

  9. Transmission line capital costs

    International Nuclear Information System (INIS)

    Hughes, K.R.; Brown, D.R.

    1995-05-01

    The displacement or deferral of conventional AC transmission line installation is a key benefit associated with several technologies being developed with the support of the U.S. Department of Energy's Office of Energy Management (OEM). Previous benefits assessments conducted within OEM have been based on significantly different assumptions for the average cost per mile of AC transmission line. In response to this uncertainty, an investigation of transmission line capital cost data was initiated. The objective of this study was to develop a database for preparing preliminary estimates of transmission line costs. An extensive search of potential data sources identified databases maintained by the Bonneville Power Administration (BPA) and the Western Area Power Administration (WAPA) as superior sources of transmission line cost data. The BPA and WAPA data were adjusted to a common basis and combined together. The composite database covers voltage levels from 13.8 to 765 W, with cost estimates for a given voltage level varying depending on conductor size, tower material type, tower frame type, and number of circuits. Reported transmission line costs vary significantly, even for a given voltage level. This can usually be explained by variation in the design factors noted above and variation in environmental and land (right-of-way) costs, which are extremely site-specific. Cost estimates prepared from the composite database were compared to cost data collected by the Federal Energy Regulatory Commission (FERC) for investor-owned utilities from across the United States. The comparison was hampered because the only design specifications included with the FERC data were voltage level and line length. Working within this limitation, the FERC data were not found to differ significantly from the composite database. Therefore, the composite database was judged to be a reasonable proxy for estimating national average costs

  10. X-ray tube transformer

    International Nuclear Information System (INIS)

    1980-01-01

    An X-ray generator is described which comprises a transmission line transformer including an electrical conductor with a cavity and a second electrical conductor including helical windings disposed along a longitudinal axis within the cavity of the first conductor. The windings have a pitch which varies per unit length along the axis. There is dielectric material in the cavity for insulation and to couple electromagnetically the two conductors in response to an electric current flowing through the conductors, which have an impedance between them; this varies with distance along the axis of the helix of the second conductor. An X-ray tube is disposed along the longitudinal axis within the cavity, for radiating X-rays. The invention increases the voltage of applied voltage pulses at the remote tube-head with a transformer formed by using a spiral delay line geometry to give a tapered-impedance coaxial high voltage multiplier for pulse voltage operation. This transformer is smaller and lighter than previous designs for the same high peak voltage and power ratings. This is important because the penetration capabilities of Flash X-ray equipment increase with voltage, particularly in heavy materials such as steel. (U.K.)

  11. Social internet sites as a source of public health information.

    Science.gov (United States)

    Vance, Karl; Howe, William; Dellavalle, Robert P

    2009-04-01

    Social media websites, such as YouTube, Facebook, MySpace, Twitter, and Second Life are rapidly emerging as popular sources of health information especially for teens and young adults. Social media marketing carries the advantages of low cost, rapid transmission through a wide community, and user interaction. Disadvantages include blind authorship, lack of source citation, and presentation of opinion as fact. Dermatologists and other health care providers should recognize the importance of social media websites and their potential usefulness for disseminating health information.

  12. Generation of Flattened Multicarrier Signals from a Single Laser Source for 330 Gbps WDM-PON Transmission over 25 km SSMF

    Science.gov (United States)

    Ullah, Sibghat; Liu, Bo; Ullah, Rahat; Ahmad, Muhammad; Wang, Fu; Zhang, Lijia; Xin, Xiangjun; Memon, Kamran Ali; Khalid, Hafiz Ahmad

    2017-12-01

    A novel technique is proposed for optical frequency comb generation with a budget friendly system. A Mach-Zehnder modulator is used in connectivity with continuous wave optical signal which is filtered by rectangle optical filter and the signal is then amplified by erbium-doped fiber amplifier. With a frequency spacing of 10 GHz 33 useable OFC lines were generated with good tone to noise ratio which is quite impressive for such a cost effective setup. Each generated carrier carries differential phase shift keying based data of 10 Gbps. A total of 330 Gbps multiplexed data is successfully transmitted through a standard single mode fiber length of 25-km. During the downlink transmission the power penalties are observed to be negligible. The resulted eye diagrams are wide and promises to be a good system for wavelength division multiplexed-passive optical network.

  13. Sources of polarized neutrons

    International Nuclear Information System (INIS)

    Walter, L.

    1983-01-01

    Various sources of polarized neutrons are reviewed. Monoenergetic source produced with unpolarized or polarized beams, white sources of polarized neutrons, production by transmissions through polarized hydrogen targets and polarized thermal neutronsare discussed, with appropriate applications included. (U.K.)

  14. [Mumps vaccine virus transmission].

    Science.gov (United States)

    Otrashevskaia, E V; Kulak, M V; Otrashevskaia, A V; Karpov, I A; Fisenko, E G; Ignat'ev, G M

    2013-01-01

    In this work we report the mumps vaccine virus shedding based on the laboratory confirmed cases of the mumps virus (MuV) infection. The likely epidemiological sources of the transmitted mumps virus were children who were recently vaccinated with the mumps vaccine containing Leningrad-Zagreb or Leningrad-3 MuV. The etiology of the described cases of the horizontal transmission of both mumps vaccine viruses was confirmed by PCR with the sequential restriction analysis.

  15. Anopheles (Kerteszia cruzii (DIPTERA: CULICIDAE IN PERIDOMICILIARY AREA DURING ASYMPTOMATIC MALARIA TRANSMISSION IN THE ATLANTIC FOREST: MOLECULAR IDENTIFICATION OF BLOOD-MEAL SOURCES INDICATES HUMANS AS PRIMARY INTERMEDIATE HOSTS

    Directory of Open Access Journals (Sweden)

    Karin Kirchgatter

    2014-09-01

    Full Text Available Anopheles (Kerteszia cruzii has been implicated as the primary vector of human and simian malarias out of the Brazilian Amazon and specifically in the Atlantic Forest regions. The presence of asymptomatic human cases, parasite-positive wild monkeys and the similarity between the parasites infecting them support the discussion whether these infections can be considered as a zoonosis. Although many aspects of the biology of An. cruzii have already been addressed, studies conducted during outbreaks of malaria transmission, aiming at the analysis of blood feeding and infectivity, are missing in the Atlantic Forest. This study was conducted in the location of Palestina, Juquitiba, where annually the majority of autochthonous human cases are notified in the Atlantic Forest of the state of São Paulo. Peridomiciliary sites were selected for collection of mosquitoes in a perimeter of up to 100 m around the residences of human malaria cases. The mosquitoes were analyzed with the purpose of molecular identification of blood-meal sources and to examine the prevalence of Plasmodium. A total of 13,441 females of An. (Ker. cruzii were collected. The minimum infection rate was calculated at 0.03% and 0.01%, respectively, for P. vivax and P. malariae and only human blood was detected in the blood-fed mosquitoes analyzed. This data reinforce the hypothesis that asymptomatic human carriers are the main source of anopheline infection in the peridomiciliary area, making the probability of zoonotic transmission less likely to happen.

  16. Anopheles (Kerteszia) cruzii (Diptera: Culicidae) in peridomiciliary area during asymptomatic malaria transmission in the Atlantic Forest: molecular identification of blood-meal sources indicates humans as primary intermediate hosts.

    Science.gov (United States)

    Kirchgatter, Karin; Tubaki, Rosa Maria; Malafronte, Rosely dos Santos; Alves, Isabel Cristina; Lima, Giselle Fernandes Maciel de Castro; Guimarães, Lilian de Oliveira; Zampaulo, Robson de Almeida; Wunderlich, Gerhard

    2014-01-01

    Anopheles (Kerteszia) cruzii has been implicated as the primary vector of human and simian malarias out of the Brazilian Amazon and specifically in the Atlantic Forest regions. The presence of asymptomatic human cases, parasite-positive wild monkeys and the similarity between the parasites infecting them support the discussion whether these infections can be considered as a zoonosis. Although many aspects of the biology of An. cruzii have already been addressed, studies conducted during outbreaks of malaria transmission, aiming at the analysis of blood feeding and infectivity, are missing in the Atlantic Forest. This study was conducted in the location of Palestina, Juquitiba, where annually the majority of autochthonous human cases are notified in the Atlantic Forest of the state of São Paulo. Peridomiciliary sites were selected for collection of mosquitoes in a perimeter of up to 100 m around the residences of human malaria cases. The mosquitoes were analyzed with the purpose of molecular identification of blood-meal sources and to examine the prevalence of Plasmodium. A total of 13,441 females of An. (Ker.) cruzii were collected. The minimum infection rate was calculated at 0.03% and 0.01%, respectively, for P. vivax and P. malariae and only human blood was detected in the blood-fed mosquitoes analyzed. This data reinforce the hypothesis that asymptomatic human carriers are the main source of anopheline infection in the peridomiciliary area, making the probability of zoonotic transmission less likely to happen.

  17. Automation in tube finishing bay

    International Nuclear Information System (INIS)

    Bhatnagar, Prateek; Satyadev, B.; Raghuraman, S.; Syama Sundara Rao, B.

    1997-01-01

    Automation concept in tube finishing bay, introduced after the final pass annealing of PHWR tubes resulted in integration of number of sub-systems in synchronisation with each other to produce final cut fuel tubes of specified length, tube finish etc. The tube finishing bay which was physically segregated into four distinct areas: 1. tube spreader and stacking area, 2. I.D. sand blasting area, 3. end conditioning, wad blowing, end capping and O.D. wet grinding area, 4. tube inspection, tube cutting and stacking area has been studied

  18. Campargue-type supersonic beam sources : absolute intensities, skimmer transmission and scaling laws for mono-atomic gases He, Ne and Ar

    NARCIS (Netherlands)

    Beijerinck, H.C.W.; van Gerwen, R.J.F.; Kerstel, E.R.T.; Martens, J.F.M.; van Vliembergen, E.J.W.; Smits, M.R.T.; Kaashoek, G.H.

    1985-01-01

    The process of beam formation in a supersonic expansion into a high pressure (10-2 -1 Torr) expansion chamber, a so-called Campargue-type beam source, has been investigated, using the theoretical frame work of an ideal undisturbed expansion as a reference. Absolute values of the centre-line

  19. Single-Source AlGaAs Frequency Comb Transmitter for 661 Tbit/s Data Transmission in a 30-core Fiber

    DEFF Research Database (Denmark)

    Hu, Hao; Da Ros, Francesco; Ye, Feihong

    2016-01-01

    We demonstrate an AlGaAs-on-insulator nano-waveguide-based frequency comb with high OSNR enabling a single-source to fully load a 9.6-km heterogeneous 30-core fibre with 661 Tbit/s data achieved by 30xcores, 80xWDM, 40 Gbaud, and PDM-16QAM...

  20. Experimental Research on Multi-source Solar Energy and Air Source Heat Pump System with Serpentine Tube Energy Storage Exchangers%蓄能型蛇形管太阳能——空气源复合热泵系统实验研究

    Institute of Scientific and Technical Information of China (English)

    陈杨华; 彭辉; 郭文帅; 李钰; 陈非凡

    2013-01-01

    蛇形管蓄能型太阳能——空气源复合热泵系统结合了空气源热泵技术、太阳能利用技术和蓄能技术三者的优点,是一种高效新型的热泵系统.在搭建好实验台后,通过实验分析了该系统在常规空气源热泵供热模式、蓄冷模式、取冷模式、蓄能热泵供热模式、边蓄热边供热模式下的性能特性.实验结果证明蓄能型蛇形管太阳能——空气源复合热泵系统运行高效、安全、稳定可靠.%Multi-source solar energy and air source heat pump system with serpentine tube energy storage exchanges combine the advantages of air source heat pump, solar energy utilization technology and energy storage technology. It is a new high-efficiency heat pump system. After setting up experimental station, the performance characteristics of the system is analysed when conventional air source heat pump heating mode, cold storage mode, cold release mode, heating mode using heat storage, heat storage and heat release using solar heat pump mode is operated. Experimental results show that the system is efficient, safe, stable and reliable.

  1. Helically coiled tube heat exchanger

    International Nuclear Information System (INIS)

    Harris, A.M.

    1981-01-01

    In a heat exchanger such as a steam generator for a nuclear reactor, two or more bundles of helically coiled tubes are arranged in series with the tubes in each bundle integrally continuing through the tube bundles arranged in series therewith. Pitch values for the tubing in any pair of tube bundles, taken transverse to the path of the reactor coolant flow about the tubes, are selected as a ratio of two unequal integers to permit efficient operation of each tube bundle while maintaining the various tube bundles of the heat exchanger within a compact envelope. Preferably, the helix angle and tube pitch parallel to the path of coolant flow are constant for all tubes in a single bundle so that the tubes are of approximately the same length within each bundle

  2. Steam generator tube performance

    International Nuclear Information System (INIS)

    Tatone, O.S.; Pathania, R.S.

    1982-04-01

    The performance of steam generator tubes in water-cooled nuclear power reactors has been reviewed for 1980. Tube defects occurred at 38% of the 97 reactors surveyed. This is a marginal improvement over 1979 when defects occurred at 41% of the reactors. The number of failed tubes was also lower, 0.14% of the tubes in service in 1980 compared with 0.20% of those in service in 1979. Analysis of the causes of these failures indicates that stress corrosion cracking was the leading failure mechanism. Reactors that used all-volatile treatment of secondary water, with or without full-flow condensate demineralization since start-up showed the lowest incidence of corrosion-related defects

  3. Fuel assembly guide tube

    International Nuclear Information System (INIS)

    Jabsen, F.S.

    1979-01-01

    This invention is directed toward a nuclear fuel assembly guide tube arrangement which restrains spacer grid movement due to coolant flow and which offers secondary means for supporting a fuel assembly during handling and transfer operations

  4. Bull Moose Tube Company

    Science.gov (United States)

    The EPA is providing notice of a proposed Administrative Penalty Assessment against the Bull Moose Tube Company, a business located at 1819 Clarkson Road, Chesterfield, MO, 63017, for alleged violations at the facility located at 406 East Industrial Drive,

  5. Tracheostomy tube - eating

    Science.gov (United States)

    Trach - eating ... take your first bites. Certain factors may make eating or swallowing harder, such as: Changes in the ... easier to swallow. Suction the tracheostomy tube before eating. This will keep you from coughing while eating, ...

  6. Researching YouTube

    OpenAIRE

    Arthurs, Jane; Drakopoulou, Sophia; Gandini, Alessandro

    2018-01-01

    ‘Researching YouTube’ introduces the special issue of Convergence which arose out of an international academic conference on YouTube that was held in London at Middlesex University in September 2016. The conference aimed to generate a robust overview of YouTube’s changing character and significance after its first ten years of development by creating a productive dialogue between speakers from different disciplines and cultures, and between YouTube-specific research and wider debates in media...

  7. Tubing crimping pliers

    Science.gov (United States)

    Lindholm, G.T.

    1981-02-27

    The disclosure relates to pliers and more particularly to pliers for crimping two or more pieces of copper tubing together prior to their being permanently joined by brazing, soldering or the like. A die containing spring-loaded pins rotates within a cammed ring in the head of the pliers. As the die rotates, the pins force a crimp on tubing held within the pliers.

  8. a Study of Ultrasonic Wave Propagation Through Parallel Arrays of Immersed Tubes

    Science.gov (United States)

    Cocker, R. P.; Challis, R. E.

    1996-06-01

    Tubular array structures are a very common component in industrial heat exchanging plant and the non-destructive testing of these arrays is essential. Acoustic methods using microphones or ultrasound are attractive but require a thorough understanding of the acoustic properties of tube arrays. This paper details the development and testing of a small-scale physical model of a tube array to verify the predictions of a theoretical model for acoustic propagation through tube arrays developed by Heckl, Mulholland, and Huang [1-5] as a basis for the consideration of small-scale physical models in the development of non-destructive testing procedures for tube arrays. Their model predicts transmission spectra for plane waves incident on an array of tubes arranged in straight rows. Relative transmission is frequency dependent with bands of high and low attenuation caused by resonances within individual tubes and between tubes in the array. As the number of rows in the array increases the relative transmission spectrum becomes more complex, with increasingly well-defined bands of high and low attenuation. Diffraction of acoustic waves with wavelengths less than the tube spacing is predicted and appears as step reductions in the transmission spectrum at frequencies corresponding to integer multiples of the tube spacing. Experiments with the physical model confirm the principle features of the theoretical treatment.

  9. Pressure tube reactor

    International Nuclear Information System (INIS)

    Seki, Osamu; Kumasaka, Katsuyuki.

    1988-01-01

    Purpose: To remove the heat of reactor core using a great amount of moderators at the periphery of the reactor core as coolants. Constitution: Heat of a reactor core is removed by disposing a spontaneous recycling cooling device for cooling moderators in a moderator tank, without using additional power driven equipments. That is, a spontaneous recycling cooling device for cooling the moderators in the moderator tank is disposed. Further, the gap between the inner wall of a pressure tube guide pipe disposed through the vertical direction of a moderator tank and the outer wall of a pressure tube inserted through the guide pipe is made smaller than the rupture distortion caused by the thermal expansion upon overheating of the pressure tube and greater than the minimum gap required for heat shiels between the pressure tube and the pressure tube guide pipe during usual operation. In this way, even if such an accident as can not using a coolant cooling device comprising power driven equipment should occur in the pressure tube type reactor, the rise in the temperature of the reactor core can be retarded to obtain a margin with time. (Kamimura, M.)

  10. Tube spacer grid for a heat-exchanger tube bundle

    International Nuclear Information System (INIS)

    Scheidl, H.

    1976-01-01

    A tube spacer grid for a heat-exchanger tube bundle is formed by an annular grid frame having a groove formed in its inner surface in which the interspaced grid bars have their ends positioned and held in interspaced relationship by short sections of tubes passed through holes axially formed in the grid frame so that the tubes are positioned between the ends of the grid bars in the grooves. The tube sections may be cut from the same tubes used to form the tube bundle. 5 claims, 3 drawing figures

  11. Penetrameter positioner for bore-side radiography of tubes

    International Nuclear Information System (INIS)

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

    1983-01-01

    A positioner is provided for placing plaque or wire penetrameters, as used in radiographic inspection, in close proximity with the inner wall of tubing at any desired location along the tubing. The positioner head carrying the penetrameter is inflatable whereby it is positioned in the deflated condition, inflated to place the penetrameter against a weld to be inspected in the tubing wall, and then deflated during removal. If desired, the penetrameter holder may be used to center the radiographic source on the axis of the tube

  12. Negative refraction of elastic waves in 2D phononic crystals: Contribution of resonant transmissions to the construction of the image of a point source

    Directory of Open Access Journals (Sweden)

    Anne-Christine Hladky-Hennion

    2011-12-01

    Full Text Available Negative refraction properties of a two-dimensional phononic crystal (PC, made of a triangular lattice of steel rods embedded in epoxy are investigated both experimentally and numerically. First, experiments have been carried out on a prism shaped PC immersed in water. Then, for focusing purposes, a flat lens is considered and the construction of the image of a point source is analyzed in details, when indices are matched between the PC and the surrounding fluid medium, whereas acoustic impedances are mismatched. Optimal conditions for focusing longitudinal elastic waves by such PC flat lens are then discussed.

  13. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... search for current job openings visit HHS USAJobs Home >> NEI YouTube Videos >> NEI YouTube Videos: Amblyopia Listen NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia Animations Blindness Cataract ...

  14. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... search for current job openings visit HHS USAJobs Home » NEI YouTube Videos » NEI YouTube Videos: Amblyopia Listen NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia Animations Blindness Cataract ...

  15. Transmission from theory to practice: Experiences using open-source code development and a virtual short course to increase the adoption of new theoretical approaches

    Science.gov (United States)

    Harman, C. J.

    2015-12-01

    Even amongst the academic community, new theoretical tools can remain underutilized due to the investment of time and resources required to understand and implement them. This surely limits the frequency that new theory is rigorously tested against data by scientists outside the group that developed it, and limits the impact that new tools could have on the advancement of science. Reducing the barriers to adoption through online education and open-source code can bridge the gap between theory and data, forging new collaborations, and advancing science. A pilot venture aimed at increasing the adoption of a new theory of time-variable transit time distributions was begun in July 2015 as a collaboration between Johns Hopkins University and The Consortium of Universities for the Advancement of Hydrologic Science (CUAHSI). There were four main components to the venture: a public online seminar covering the theory, an open source code repository, a virtual short course designed to help participants apply the theory to their data, and an online forum to maintain discussion and build a community of users. 18 participants were selected for the non-public components based on their responses in an application, and were asked to fill out a course evaluation at the end of the short course, and again several months later. These evaluations, along with participation in the forum and on-going contact with the organizer suggest strengths and weaknesses in this combination of components to assist participants in adopting new tools.

  16. Transcending Transmission

    DEFF Research Database (Denmark)

    Schoeneborn, Dennis; Trittin, Hannah

    2013-01-01

    Purpose – Extant research on corporate social responsibility (CSR) communication primarily relies on a transmission model of communication that treats organizations and communication as distinct phenomena. This approach has been criticized for neglecting the formative role of communication...... in the emergence of organizations. This paper seeks to propose to reconceptualize CSR communication by drawing on the “communication constitutes organizations” (CCO) perspective. Design/methodology/approach – This is a conceptual paper that explores the implications of switching from an instrumental...... to a constitutive notion of communication. Findings – The study brings forth four main findings: from the CCO view, organizations are constituted by several, partly dissonant, and potentially contradictory communicative practices. From that viewpoint, the potential impact of CSR communication becomes a matter...

  17. Miniature radioactive light source

    International Nuclear Information System (INIS)

    Caffarella, T.E.; Radda, G.J.; Dooley, H.H.

    1980-01-01

    A miniature radioactive light source for illuminating digital watches is described consisting of a glass tube with improved laser sealing and strength containing tritium gas and a transducer responsive to the gas. (U.K.)

  18. Tube plug removal machine

    International Nuclear Information System (INIS)

    Hawkins, P.J.

    1987-01-01

    In a nuclear steam generator wherein some faulty tubes have been isolated by mechanical plugging, to remove a selected plug without damaging the associated tube, a plug removal machine is used. The machine drills into a plug portion with a tap drill bit having a drill portion a tap portion and a threaded portion, engaging that plug portion with the threaded portion after the drilled hole has been threaded by the tap portion thereof, and removing a portion of the plug in the tube with a counterbore drill bit mounted concentrically about the tap drill bit. A trip pin and trip spline disengage the tap drill bit from the motor. The counterbore drill bit is thereafter self-centered with respect to the tube and plug about the now stationary tap drill bit. After a portion of the plug has been removed by the counterbore drill bit, pulling on the top drill bit by grippers on slots will remove the remaining plug portion from the tube. (author)

  19. Categorising YouTube

    Directory of Open Access Journals (Sweden)

    Thomas Mosebo Simonsen

    2011-09-01

    Full Text Available This article provides a genre analytical approach to creating a typology of the User Generated Content (UGC of YouTube. The article investigates the construction of navigationprocesses on the YouTube website. It suggests a pragmatic genre approach that is expanded through a focus on YouTube’s technological affordances. Through an analysis of the different pragmatic contexts of YouTube, it is argued that a taxonomic understanding of YouTube must be analysed in regards to the vacillation of a user-driven bottom-up folksonomy and a hierarchical browsing system that emphasises a culture of competition and which favours the already popular content of YouTube. With this taxonomic approach, the UGC videos are registered and analysed in terms of empirically based observations. The article identifies various UGC categories and their principal characteristics. Furthermore, general tendencies of the UGC within the interacting relationship of new and old genres are discussed. It is argued that the utility of a conventional categorical system is primarily of analytical and theoretical interest rather than as a practical instrument.

  20. Measuring of tube expansion

    International Nuclear Information System (INIS)

    Vogeleer, J. P.

    1985-01-01

    The expansion of the primary tubes or sleeves of the steam generator of a nuclear reactor plant are measured while the tubes or sleeves are being expanded. A primary tube or sleeve is expanded by high pressure of water which flows through a channel in an expander body. The water is supplied through an elongated conductor and is introduced through a connector on the shank connected to the conductor at its outer end. A wire extends through the mandrel and through the conductor to the end of the connector. At its inner end the wire is connected to a tapered pin which is subject to counteracting forces produced by the pressure of the water. The force on the side where the wire is connected to the conductor is smaller than on the opposite side. The tapered pin is moved in the direction of the higher force and extrudes the wire outwardly of the conductor. The tapered surface of the tapered pin engages transverse captive plungers which are maintained in engagement with the expanding tube or sleeve as they are moved outwardly by the tapered pin. The wire and the connector extend out of the generator and, at its outer end, the wire is connected to an indicator which measures the extent to which the wire is moved by the tapered pin, thus measuring the expansion of the tube or sleeve as it progresses

  1. 3D non-contrast-enhanced ECG-gated MR angiography of the lower extremities with dual-source radiofrequency transmission at 3.0 T: Intraindividual comparison with contrast-enhanced MR angiography in PAOD patients.

    Science.gov (United States)

    Rasper, Michael; Wildgruber, Moritz; Settles, Marcus; Eckstein, Hans-Henning; Zimmermann, Alexander; Reeps, Christian; Rummeny, Ernst J; Huber, Armin M

    2016-09-01

    To compare prospectively image quality and diagnostic confidence of flow-sensitive 3D turbo spin echo (TSE)-based non-contrast-enhanced MR angiography (NE-MRA) at 3.0 T using dual-source radiofrequency (RF) transmission with contrast-enhanced MRA (CE-MRA) in patients with peripheral arterial occlusive disease (PAOD). After consent was obtained, 35 patients (mean age 69.1 ± 10.6 years) with PAOD stage II-IV underwent NE-MRA followed by CE-MRA. Signal-to-noise ratio and contrast-to-noise ratio were calculated. Subjective image quality was independently assessed by two radiologists and stenosis scoring was performed in 875 arterial segments. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for stenosis classification were calculated using CE-MRA as a reference method. Diagnostic agreement with CE-MRA was evaluated with Cohen's kappa statistics. NE-MRA provided high objective and subjective image quality at all levels of the arterial tree. Sensitivity and specificity for the detection of relevant stenosis was 91 % and 89 %, respectively; the NPV was 96 % and the PPV 78 %. There was good concordance between CE-MRA and NE-MRA in stenosis scoring. 3D electrocardiography (ECG)-gated TSE NE-MRA with patient-adaptive dual-source RF transmission at 3.0 T is a promising alternative for PAOD patients with contraindications for gadolinium-based contrast agents. It offers high sensitivity and NPV values in the detection of clinically relevant arterial stenosis. • Flow-sensitive TSE NE-MRA is a promising technique for PAOD evaluation. • Diagnostic accuracy is comparable to contrast-enhanced MRA. • NE-MRA eliminates the risk of NSF in patients with renal insufficiency. • Costs arising from the use of contrast agents can be avoided.

  2. X-ray sources

    International Nuclear Information System (INIS)

    Masswig, I.

    1986-01-01

    The tkb market survey comparatively evaluates the X-ray sources and replacement tubes for stationary equipment currently available on the German market. It lists the equipment parameters of 235 commercially available X-ray sources and their replacement tubes and gives the criteria for purchase decisions. The survey has been completed with December 1985, and offers good information concerning medical and technical aspects as well as those of safety and maintenance. (orig.) [de

  3. Advanced evacuated tube collectors

    Science.gov (United States)

    Schertz, W. W.; Hull, J. R.; Winston, R.; Ogallagher, J.

    1985-04-01

    The essence of the design concept for these new collectors is the integration of moderate levels of nonimaging concentration inside the evacuated tube itself. This permanently protects the reflection surfaces and allows the use of highly reflecting front surface mirrors with reflectances greater than 95%. Previous fabrication and long term testing of a proof-of-concept prototype has established the technical success of the concept. Present work is directed toward the development of a manufacturable unit that will be suitable for the widest possible range of applications. Design alternatives include scaling up the original prototype's tube diameter from 5 cm to 10 cm, using an internal shaped metal concentrating reflector, using a variety of profile shapes to minimize so-called gap losses and accommodate both single ended and double-ended flow geometries, and allowing the use of heat pipes for the absorber tube.

  4. Square through tube

    International Nuclear Information System (INIS)

    Akita, Junji; Honma, Toei.

    1975-01-01

    Object: To provide a square through tube involving thermal movement in pipelines such as water supply pump driving turbine exhaust pipe (square-shaped), which is wide in freedom with respect to shape and dimension thereof for efficient installation at site. Structure: In a through tube to be airtightly retained for purpose of decontamination in an atomic power plant, comprising a seal rubber plate, a band and a bolt and a nut for securing said plate, the seal rubber plate being worked into the desired shape so that it may be placed in intimate contact with the concrete floor surface by utilization of elasticity of rubber, thereby providing airtightness at a corner portion of the square tube. (Kamimura, M.)

  5. Electrical properties of various types of straw tubes considered for the LHCb outer tracker

    CERN Document Server

    Gromov, V

    2001-01-01

    Because of the appreciable length (up to 3.6 m) of the straw tube modules of the Outer Tracker, transmission line effects will have impact on their operational properties. These effects were clearly observed in a 1.6 m long prototype. A few types of straw tubes have been examined from the point of view of electrical properties, with emphasis on the study of signal transmission and cross-talk.

  6. Gamma sensitivity of pressurized drift tubes

    International Nuclear Information System (INIS)

    Baranov, S.A.; Bojko, I.R.; Shelkov, G.A.; Ignatenko, M.A.

    1995-01-01

    Using a set of commonly used radioactive sources, the efficiency of pressurized drift tubes for gammas with energy from 5.9 keV up to 1.3 MeV has been measured. The tube was made of aluminium and filled with Ar, 15%CO 2 and 2.5%iC 4 H 10 gas mixture at 3 atm. The measured efficiency is compared with the results of the calculations in the frame of our simple model as well as with that of the Monte Carlo simulation using GEANT code. The results of our calculations are in agreement with experimental data, while GEANT simulation tends to give lower efficiency in the energy range of 200 keV γ <1300 keV. The average efficiency of the tube in the field of ATLAS gamma background is about 0.45%. 8 refs., 7 figs., 1 tab

  7. PRODUCTION OF URANIUM TUBING

    Science.gov (United States)

    Creutz, E.C.

    1958-04-15

    The manufacture of thin-walled uranium tubing by the hot-piercing techique is described. Uranium billets are preheated to a temperature above 780 d C. The heated billet is fed to a station where it is engaged on its external surface by three convex-surfaced rotating rollers which are set at an angle to the axis of the billet to produce a surface friction force in one direction to force the billet over a piercing mandrel. While being formed around the mandrel and before losing the desired shape, the tube thus formed is cooled by a water spray.

  8. Guide tube sleeve

    International Nuclear Information System (INIS)

    Attix, D.J.

    1983-01-01

    The invention increases the operating capacity of a nuclear reactor by causing a modification in the flow pattern of the coolant which enhances the coolant's effectiveness. The apparatus provides a thin-walled tubular sleeve closely surrounding but not attached to the exterior surface of a guide tube in a fuel assembly. The wall of the sleeve has tabs projecting outwardly into adjacent flow channels. The sleeve is attached to the wall of a cellular void through which passes the guide tube associated with said sleeve. The tabs increase the flow of water in the channel and thus increase the heat transfer

  9. Photon sources for absorptiometric measurements

    International Nuclear Information System (INIS)

    Witt, R.M.; Sandrik, J.M.; Cameron, J.R.

    1976-01-01

    Photon absorptiometry is defined and the requirements of photon sources for these measurements are described. Both x-ray tubes and radionuclide sources are discussed, including the advantages of each in absorptiometric systems

  10. Flow tube used to cool solar-pumped laser

    Science.gov (United States)

    1968-01-01

    A flow tube has been designed and constructed to provide two major functions in the application of a laser beam for transmission of both sound and video. It maintains the YAG laser at the proper operating temperature of 300 degrees K under solar pumping conditions, and it serves as a pump cavity for the laser crystal.

  11. Pressure tube type research reactor

    International Nuclear Information System (INIS)

    Ueda, Hiroshi.

    1976-01-01

    Object: To prevent excessive heat generation due to radiation of a pressure tube vessel. Structure: A pressure tube encasing therein a core comprises a dual construction comprising inner and outer tubes coaxially disposed. High speed cooling water is passed through the inner tube for cooling. In addition, in the outer periphery of said outer tube there is provided a forced cooling tube disposed coaxially thereto, into which cooling fluid, for example, such as moderator or reflector is forcibly passed. This forced cooling tube has its outer periphery surrounded by the vessel into which moderator or reflector is fed. By the provision of the dual construction of the pressure tube and the forced cooling tube, the vessel may be prevented from heat generation. (Ikeda, J.)

  12. The first report of human-derived G10 genotype of Echinococcus canadensis in China and possible sources and routes of transmission.

    Science.gov (United States)

    Yang, Dong; Zhang, Tiemin; Zeng, Zhaolin; Zhao, Wei; Zhang, Weizhe; Liu, Aiqin

    2015-10-01

    Cystic echinococcosis (CE) is one of the most important parasitic zoonoses. 10 distinct genotypes, designated G1-G10 genotypes of Echinococcus granulosus sensu lato (s.l.), have been split into 4 species: Echinococcus granulosus sensu stricto (s.s.) (G1-G3), Echinococcus equinus (G4), Echinococcus ortleppi (G5) and Echinococcus canadensis (G6-G10); Echinococcus felidis has also been suggested as a sister taxon of E. granulosus s.s. recently. Four genotypes belonging to two species (G1 and G3 genotypes of E. granulosus s.s., and G6 and G7 genotypes of E. canadensis) have been identified in humans and animals in China. In the present study, a human-derived hydatid cyst from a patient in northeastern China's Heilongjiang Province was identified as G10 genotype of E. canadensis based on mitochondrial cytochrome c oxidase subunit I (cox1), cytochrome b (cytb) and NADH dehydrogenase subunit 1 (nad1) genes. Homology analysis showed the cox1 gene sequence of G10 genotype of E. canadensis had 100% homology with those from wolves in Mongolia and from a moose in Russia. The cytb and nad1 gene sequences of G10 genotype of E. canadensis had 100% homology with the complete sequence from a moose in Finland at an amino acid level. The infection source of the CE patient here might be primarily attributable to wolves. This is the first report of G10 genotype of E. canadensis in a human in China. The finding of G10 genotype of E. canadensis in China shows that this genotype possibly has a more wide geographical distribution than previously considered. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  13. Method and apparatus for remote tube crevice detection by current and voltage probe resistance measurement

    Science.gov (United States)

    Kikta, Thomas J.; Mitchell, Ronald D.

    1992-01-01

    A method and apparatus for determining the extent of contact between an electrically conducting tube and an electrically conductive tubesheet surrounding the tube, based upon the electrical resistance of the tube and tubesheet. A constant current source is applied to the interior of the electrically conducting tube by probes and a voltmeter is connected between other probes to measure the voltage at the point of current injection, which is inversely proportional to the amount of contact between the tube and tubesheet. Namely, the higher the voltage measured by the voltmeter, the less contact between the tube and tubesheet.

  14. Double wall steam generator tubing

    International Nuclear Information System (INIS)

    Padden, T.R.; Uber, C.F.

    1983-01-01

    Double-walled steam generator tubing for the steam generators of a liquid metal cooled fast breeder reactor prevents sliding between the surfaces due to a mechanical interlock. Forces resulting from differential thermal expansion between the outer tube and the inner tube are insufficient in magnitude to cause shearing of base metal. The interlock is formed by jointly drawing the tubing, with the inside wall of the outer tube being already formed with grooves. The drawing causes the outer wall of the inner tube to form corrugations locking with the grooves. (author)

  15. Tube-dwelling invertebrates

    NARCIS (Netherlands)

    Hölker, Franz; Vanni, Michael J.; Kuiper, Jan J.; Meile, Christof; Grossart, Hans Peter; Stief, Peter; Adrian, Rita; Lorke, Andreas; Dellwig, Olaf; Brand, Andreas; Hupfer, Michael; Mooij, Wolf M.; Nützmann, Gunnar; Lewandowski, Jörg

    2015-01-01

    There is ample evidence that tube-dwelling invertebrates such as chironomids significantly alter multiple important ecosystem functions, particularly in shallow lakes. Chironomids pump large water volumes, and associated suspended and dissolved substances, through the sediment and thereby compete

  16. Cladding tube manufacturing technology

    International Nuclear Information System (INIS)

    Hahn, R.; Jeong, Y. H.; Baek, B. J.; Kim, K. H.; Kim, S. J.; Choi, B. K.; Kim, J. M.

    1999-04-01

    This report gives an overview of the manufacturing routine of PWR cladding tubes. The routine essentially consists of a series of deformation and annealing processes which are necessary to transform the ingot geometry to tube dimensions. By changing shape, microstructure and structure-related properties are altered simultaneously. First, a short overview of the basics of that part of deformation geometry is given which is related to tube reducing operations. Then those processes of the manufacturing routine which change the microstructure are depicted, and the influence of certain process parameters on microstructure and material properties are shown. The influence of the resulting microstructure on material properties is not discussed in detail, since it is described in my previous report A lloy Development for High Burnup Cladding . Because of their paramount importance still up to now, and because manufacturing data and their influence on properties for other alloys are not so well established or published, the descriptions are mostly related to Zry4 tube manufacturing, and are only in short for other alloys. (author). 9 refs., 46 figs

  17. Thoughts on accelerator tubes

    International Nuclear Information System (INIS)

    Larson, J.D.

    1978-01-01

    A brief, subjective review is given of mechanisms that may be limiting electrostatic accelerator tubes to present levels of performance. Suggestions are made for attacking these limitations with the purpose of stimulating the thinking of designers and users of electrostatic accelerators

  18. Tracheostomy tube - speaking

    Science.gov (United States)

    ... with others. However, you can learn how to speak with a tracheostomy tube. It just takes practice. There ... If it is hard to speak with a trach in place, special devices can help you learn to create sounds. One-way valves, called speaking valves, are placed ...

  19. Thoughts of accelerator tubes

    International Nuclear Information System (INIS)

    Larson, J.D.

    1977-01-01

    A brief, subjective review is given of mechanisms that may be limiting electrostatic accelerator tubes to present levels of performance. Suggestions are made for attacking these limitations with the purpose of stimulating the thinking of designers and users of electrostatic accelerators

  20. Cladding tube manufacturing technology

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, R. [Kraftwerk Union AG, Mulheim (Germany); Jeong, Y.H.; Baek, B.J.; Kim, K.H.; Kim, S.J.; Choi, B.K.; Kim, J.M. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1999-04-01

    This report gives an overview of the manufacturing routine of PWR cladding tubes. The routine essentially consists of a series of deformation and annealing processes which are necessary to transform the ingot geometry to tube dimensions. By changing shape, microstructure and structure-related properties are altered simultaneously. First, a short overview of the basics of that part of deformation geometry is given which is related to tube reducing operations. Then those processes of the manufacturing routine which change the microstructure are depicted, and the influence of certain process parameters on microstructure and material properties are shown. The influence of the resulting microstructure on material properties is not discussed in detail, since it is described in my previous report 'Alloy Development for High Burnup Cladding.' Because of their paramount importance still up to now, and because manufacturing data and their influence on properties for other alloys are not so well established or published, the descriptions are mostly related to Zry4 tube manufacturing, and are only in short for other alloys. (author). 9 refs., 46 figs.

  1. Transmission Line Series Compensation for Wind Energy Transmission

    International Nuclear Information System (INIS)

    Palanichamy, C; Wong, Y C

    2015-01-01

    Wind energy has demonstrated to be a clean, copious and absolutely renewable source of energy, and the large penetration of it into the power grid indicates that wind energy is considered an effective means of power generation, Transmission of wind energy from remote locations to load centers necessitates long transmission lines. Series compensation is a proven and economical transmission solution to address system power transfer strength, grid stability, and voltage profile issues of long transmission lines. In this paper, a programmable approach to determine the capacitive reactance of series capacitor and optimum location for its placement to achieve maximum power transfer gas been presented. The respective program with sample solutions has been provided for real-time applications. (paper)

  2. Drift tubes of Linac 2

    CERN Multimedia

    Photographic Service

    1977-01-01

    Being redied for installation, those at the right are for tank 1, those on the left for tank 2. Contrary to Linac 1, which had drift-tubes supported on stems, here the tubes are suspended, for better mechanical stability.

  3. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... YouTube Videos: Amblyopia Embedded video for NEI YouTube Videos: Amblyopia ... *PDF files require the free Adobe® Reader® software for viewing. This website is maintained by the ...

  4. Tubing For Sampling Hydrazine Vapor

    Science.gov (United States)

    Travis, Josh; Taffe, Patricia S.; Rose-Pehrsson, Susan L.; Wyatt, Jeffrey R.

    1993-01-01

    Report evaluates flexible tubing used for transporting such hypergolic vapors as those of hydrazines for quantitative analysis. Describes experiments in which variety of tubing materials, chosen for their known compatibility with hydrazine, flexibility, and resistance to heat.

  5. Prospects for stronger calandria tubes

    International Nuclear Information System (INIS)

    Ells, C.E.; Coleman, C.E.; Hosbons, R.R.; Ibrahim, E.F.; Doubt, G.L.

    1990-12-01

    The CANDU calandria tubes, made of seam welded and annealed Zircaloy-2, have given exemplary service in-reactor. Although not designed as a system pressure containment, calandria tubes may remain intact even in the face of pressure tube rupture. One such incident at Pickering Unit 2 demonstrated the economic advantage of such an outcome, and a case can be made for increasing the probability that other calandria tubes would perform in a similar fashion. Various methods of obtaining stronger calandria tubes are available, and reviewed here. When the tubes are internally pressurized, the weld is the weak section of the tube. Increasing the oxygen concentration in the starting sheet, and thickening the weld, are promising routes to a stronger tube

  6. Carbon nano tubes embedded in polymer nano fibers

    International Nuclear Information System (INIS)

    Dror, Y.; Kedem, S.; Khalfin, R.L.; Paz, Y.; Cohenl, Y.; Salalha, Y.; Yarin, A.L.; Zussman, A.

    2004-01-01

    Full Text: The electro spinning process was used successfully to embed Multi-walled carbon nano tubes (MWCNTs) and single-walled carbon nano tubes (SWCNTs) in a matrix of poly(ethylene oxide) (PEO) forming composite nano fibers. Initial dispersion of SWCNTs in water was achieved by the use of an amphphilic alternating copolymer of styrene and sodium maleate. MWNT dispersion was achieved by ionic and nonionic surfactants. The distribution and conformation of the nano tubes in the nano fibers were studied by transmission electron microscopy (TEM). Oxygen plasma etching was used to expose the nano tubes within the nano fibers to facilitate direct observation. Nano tube alignment within the nano fibers was shown to depend strongly on the quality of the initial dispersions. Well-dispersed and separated nano tubes were embedded in a straight and aligned form while entangled non-separated nano tubes were incorporated as dense aggregates. X-ray diffraction demonstrated a high degree of orientation of the PEO crystals in the electro spun nano fibers with embedded SWCNTs, whereas incorporation of MVCNTs had a detrimental effect on the polymer orientation. Composite polymer nano fibers containing dispersed phases of nanometric TiO 2 particles and MWCNTs were also prepared electro spinning. In this case, the polymer matrix was poly(acrylonitrile) (PAN). The morphology and possible applications of these composite nano fibers will be discussed

  7. Available transmission capacity assessment

    Directory of Open Access Journals (Sweden)

    Škokljev Ivan

    2012-01-01

    Full Text Available Effective power system operation requires the analysis of vast amounts of information. Power market activities expose power transmission networks to high-level power transactions that threaten normal, secure operation of the power system. When there are service requests for a specific sink/source pair in a transmission system, the transmission system operator (TSO must allocate the available transfer capacity (ATC. It is common that ATC has a single numerical value. Additionally, the ATC must be calculated for the base case configuration of the system, while generation dispatch and topology remain unchanged during the calculation. Posting ATC on the internet should benefit prospective users by aiding them in formulating their requests. However, a single numerical value of ATC offers little for prospect for analysis, planning, what-if combinations, etc. A symbolic approach to the power flow problem (DC power flow and ATC offers a numerical computation at the very end, whilst the calculation beforehand is performed by using symbols for the general topology of the electrical network. Qualitative analysis of the ATC using only qualitative values, such as increase, decrease or no change, offers some new insights into ATC evaluation, multiple transactions evaluation, value of counter-flows and their impact etc. Symbolic analysis in this paper is performed after the execution of the linear, symbolic DC power flow. As control variables, the mathematical model comprises linear security constraints, ATC, PTDFs and transactions. The aim is to perform an ATC sensitivity study on a five nodes/seven lines transmission network, used for zonal market activities tests. A relatively complicated environment with twenty possible bilateral transactions is observed.

  8. Expansion lyre-shaped tube

    International Nuclear Information System (INIS)

    Andro, Jean.

    1973-01-01

    The invention relates the expansion lyre-shaped tube portions formed in dudgeoned tubular bundles between two bottom plates. An expansion lyre comprises at least two sets of tubes of unequal lengths coplanar and symmetrical with respect to the main tube axis, with connecting portions between the tubes forming said sets. The invention applies to apparatus such as heat exchangers, heaters, superheaters or breeders [fr

  9. Chest tube insertion - series (image)

    Science.gov (United States)

    Chest tubes are inserted to drain blood, fluid, or air and allow full expansion of the lungs. The tube is placed in the pleural space. The area where the tube will be inserted is numbed (local anesthesia). The patient may also be sedated. The chest ...

  10. Tube Length and Water Flow

    Directory of Open Access Journals (Sweden)

    Ben Ruktantichoke

    2011-06-01

    Full Text Available In this study water flowed through a straight horizontal plastic tube placed at the bottom of a large tank of water. The effect of changing the length of tubing on the velocity of flow was investigated. It was found that the Hagen-Poiseuille Equation is valid when the effect of water entering the tube is accounted for.

  11. Tubing cutter for tight spaces

    Science.gov (United States)

    Girala, A. S.

    1980-01-01

    Cutter requires few short swings of handle to rotate its cutting edge full 360 around tube. It will cut tubing installed in confined space that prevents free movement of conventional cutter. Cutter is snapped onto tube and held in place by spring-loaded clamp. Screw ratchet advances cutting wheel.

  12. Heat Exchanger Tube to Tube Sheet Joints Corrosion Behavior

    Directory of Open Access Journals (Sweden)

    M. Iancu

    2013-03-01

    Full Text Available Paper presents the studies made by the authors above the tube to tube sheet fittings of heat exchanger with fixed covers from hydrofining oil reforming unit. Tube fittings are critical zones for heat exchangers failures. On a device made from material tube and tube sheet at real joints dimensions were establish axial compression force and traction force at which tube is extracted from expanded joint. Were used two shapes joints with two types of fittings surfaces, one with smooth hole of tube sheet and other in which on boring surface we made a groove. From extracted expanded tube zones were made samples for corrosion tests in order to establish the corrosion rate, corrosion potential and corrosion current in working mediums such as hydrofining oil and industrial water at different temperatures. The corrosion rate values and the temperature influence are important to evaluate joints durability and also the results obtained shows that the boring tube sheet shape with a groove on hole tube shape presents a better corrosion behavior then the shape with smooth hole tube sheet.

  13. YouTube Physics

    Science.gov (United States)

    Riendeau, Diane

    2012-09-01

    To date, this column has presented videos to show in class, Don Mathieson from Tulsa Community College suggested that YouTube could be used in another fashion. In Don's experience, his students are not always prepared for the mathematic rigor of his course. Even at the high school level, math can be a barrier for physics students. Walid Shihabi, a colleague of Don's, decided to compile a list of YouTube videos that his students could watch to relearn basic mathematics. I thought this sounded like a fantastic idea and a great service to the students. Walid graciously agreed to share his list and I have reproduced a large portion of it below.

  14. Neutron image intensifier tubes

    International Nuclear Information System (INIS)

    Verat, M.; Rougeot, H.; Driard, B.

    1983-01-01

    The most frequently used techniques in neutron radiography employ a neutron converter consisting of either a scintillator or a thin metal sheet. The radiation created by the neutrons exposes a photographic film that is in contact with the converter: in the direct method, the film is exposed during the time that the object is irradiated with neutrons; in the transfer method, the film is exposed after the irradiation of the object with neutrons. In industrial non-destructive testing, when many identical objects have to be checked, these techniques have several disadvantages. Non-destructive testing systems without these disadvantages can be constructed around neutron-image intensifier tubes. A description and the operating characteristics of neutron-image intensifier tubes are given. (Auth.)

  15. Tube coupling device

    Science.gov (United States)

    Myers, William N. (Inventor); Hein, Leopold A. (Inventor)

    1987-01-01

    A first annular ring of a tube coupling device has a keyed opening sized to fit around the nut region of a male coupling, and a second annular ring has a keyed opening sized to fit around the nut of a female coupling. Each ring has mating ratchet teeth and these rings are biased together, thereby engaging these teeth and preventing rotation of these rings. This in turn prevents the rotation of the male nut region with respect to the female nut. For tube-to-bulkhead locking, one facet of one ring is notched, and a pin is pressed into an opening in the bulkhead. This pin is sized to fit within one of the notches in the ring, thereby preventing rotation of this ring with respect to the bulkhead.

  16. PEG Tube Placement

    Directory of Open Access Journals (Sweden)

    Saptarshi Biswas

    2014-01-01

    Full Text Available Percutaneous endoscopic gastrostomy (PEG has been used for providing enteral access to patients who require long-term enteral nutrition for years. Although generally considered safe, PEG tube placement can be associated with many immediate and delayed complications. Buried bumper syndrome (BBS is one of the uncommon and late complications of percutaneous endoscopic gastrostomy (PEG placement. It occurs when the internal bumper of the PEG tube erodes into the gastric wall and lodges itself between the gastric wall and skin. This can lead to a variety of additional complications such as wound infection, peritonitis, and necrotizing fasciitis. We present here a case of buried bumper syndrome which caused extensive necrosis of the anterior abdominal wall.

  17. Transmission electron microscopy of bone

    NARCIS (Netherlands)

    Everts, Vincent; Niehof, Anneke; Tigchelaar-Gutter, Wikky; Beertsen, Wouter

    2012-01-01

    This chapter describes procedures to process mineralized tissues obtained from different sources for transmission electron microscopy (TEM). Methods for fixation, resin embedding, staining of semi-thin sections and ultrathin sections are presented. In addition, attention will be paid to processing

  18. Recurrent inspection of tubes

    International Nuclear Information System (INIS)

    Andersson, S.

    1984-01-01

    Recommendations concerning the selection of areas for the inspection of tubes have been outlined. The aim is to focus the control on the regions which are important for the safety and where damage is supposed to take place. The number of zones will depend on the risk factors as judged by experts. The localizing will be based upon probable damaging mechanisms. A certain number of areas should be chosen at random. (G.B.)

  19. Cathode ray tube screens

    International Nuclear Information System (INIS)

    Cockayne, B.; Robbins, D.J.; Glasper, J.L.

    1982-01-01

    An improved cathode ray tube screen is described which consists of a single- or a poly-crystalline slice of a material such as yttrium aluminium garnet in which dopants such as Tb 3 + , Eu 3 + , Ce 3 + or Tm 3 + are ion implanted to different depths or in different areas of the screen. Annealing the screen removes lattice damage caused by the ion implanting and assists the diffusion of the dopant into the crystal. (U.K.)

  20. Cathode ray tube

    International Nuclear Information System (INIS)

    1979-01-01

    A cathode ray tube comprises two electron lens means in combination to crossover the electron beam at a second crossover between the two electron lens means with one of the two lens means having a variable voltage applied thereto to control the location of the beam crossover in order to focus the beam onto a display screen at any location away from the screen center. (Auth.)

  1. Fabrication of seamless calandria tubes

    International Nuclear Information System (INIS)

    Saibaba, N.; Phanibabu, C.; Bhaskara Rao, C.V.; Kalidas, R.; Ganguly, C.

    2002-01-01

    Full text: Calandria tube is a large diameter, thin walled zircaloy-4 tube and is an important structural component of PHWR type of reactors. These tubes are lifetime components and remain during the full life of the reactor. Calandria tubes are classified as extremely thin walled tubes with a diameter to wall thickness ratio of around 96. Such thin walled tubes are conventionally produced by seam welded route comprising of extrusion of slabs followed by a series of hot and rolling passes, shaping into O-shape and eventual welding. An alternative and superior method of fabricating the calandria tubes, the seamless route, has been developed, which involves hot extrusion of mother blanks followed by three successive cold pilger reductions. Eccentricity correction of the extruded blanks is carried out on a special purpose grinding equipment to bring the wall thickness variation within permissible limits. Predominant wall thickness reductions are given during cold pilgering to ensure high Q-factor values. The texture in the finished tubes could be closely, controlled with an average f r value of 0.65. Pilgering parameters and tube guiding system have been specially designed to facilities rolling of thin walled tubes. Seamless calandria tubes have distinct advantages over welded tubes. In addition to the absence of weld, they are dimensionally more stable, lighter in weight and possess uniform grains with superior grain size. The cycle time from billet to finished product is substantially reduced and the product is amenable to high level of quality assurance. The most significant feature of the seamless route is its material recovery over welded route. Residual stresses measured in the tubes indicate that these are negligible and uniform along the length of the tube. In view of their superior quality, the first charge of seamless calandria tubes will be rolled into the first 500 MWe Pressurised Heavy Water Reactor at Tarapur

  2. Characteristics of the JRR-3M neutron guide tubes

    International Nuclear Information System (INIS)

    Suzuki, Masatoshi; Ichikawa, Hiroki; Kawabata, Yuji.

    1993-01-01

    Large scale neutron guide tubes have been installed in the upgraded JRR-3 (Japan Research Reactor No.3, JRR-3M). The total length of the guide tubes is 232m. The neutron fluxes and spectra were measured at the end of the neutron guide tubes. The neutron fluxes of thermal neutron guide tubes with characteristic wavelength of 2A are 1.2 x 10 8 n/cm 2 · s. The neutron fluxes of cold guide tubes are 1.4 x 10 8 n/cm 2 · s with characteristic wavelength of 4A and 2.0 x 10 8 n/cm 2 · s with 6A when the cold neutron source is operated. The neutron spectra measured by time-of-flight method agree well with their designed ones. (author)

  3. Curvature and position of nested tubes in hollow-core anti-resonant fibers

    DEFF Research Database (Denmark)

    Habib, Md Selim; Markos, Christos; Bang, Ole

    2017-01-01

    Hollow-core anti-resonant (HC-AR) fibers where a symmetric distribution of cladding tubes compose a “negative-curvature” core boundary have extraordinary optical properties, such as low transmission loss, wide transmission bands and weak power overlap between the core modes and the silica parts [1...

  4. MAPLE research reactor beam-tube performance

    International Nuclear Information System (INIS)

    Lee, A.G.; Lidstone, R.F.; Gillespie, G.E.

    1989-05-01

    Atomic Energy of Canada Limited (AECL) has been developing the MAPLE (Multipurpose Applied Physics Lattice Experimental) reactor concept as a medium-flux neutron source to meet contemporary research reactor applications. This paper gives a brief description of the MAPLE reactor and presents some results of computer simulations used to analyze the neutronic performance. The computer simulations were performed to identify how the MAPLE reactor may be adapted to beam-tube applications such as neutron radiography

  5. Active control of sound transmission through partitions composed of discretely controlled modules

    Science.gov (United States)

    Leishman, Timothy W.

    This thesis provides a detailed theoretical and experimental investigation of active segmented partitions (ASPs) for the control of sound transmission. ASPs are physically segmented arrays of interconnected acoustically and structurally small modules that are discretely controlled using electronic controllers. Theoretical analyses of the thesis first address physical principles fundamental to ASP modeling and experimental measurement techniques. Next, they explore specific module configurations, primarily using equivalent circuits. Measured normal-incidence transmission losses and related properties of experimental ASPs are determined using plane wave tubes and the two-microphone transfer function technique. A scanning laser vibrometer is also used to evaluate distributed transmitting surface vibrations. ASPs have the inherent potential to provide excellent active sound transmission control (ASTC) through lightweight structures, using very practical control strategies. The thesis analyzes several unique ASP configurations and evaluates their abilities to produce high transmission losses via global minimization of normal transmitting surface vibrations. A novel dual diaphragm configuration is shown to employ this strategy particularly well. It uses an important combination of acoustical actuation and mechano-acoustical segmentation to produce exceptionally high transmission loss (e.g., 50 to 80 dB) over a broad frequency range-including lower audible frequencies. Such performance is shown to be comparable to that produced by much more massive partitions composed of thick layers of steel or concrete and sand. The configuration uses only simple localized error sensors and actuators, permitting effective use of independent single-channel controllers in a decentralized format. This work counteracts the commonly accepted notion that active vibration control of partitions is an ineffective means of controlling sound transmission. With appropriate construction, actuation

  6. Response analysis on nonuniform transmission line

    Directory of Open Access Journals (Sweden)

    Cvetković Zlata

    2005-01-01

    Full Text Available Transients on a loss less exponential transmission line with a pure resistance load are presented in this paper. The approach is based on the two-port presentation of the transmission line. Using Picard-Carson's method the transmission line equations are solved. The relationship between source voltage and the load voltage in s-domain is derived. All the results are plotted using program package Mathematica 3.0.

  7. Microdischarges in DC accelerator tubes

    International Nuclear Information System (INIS)

    Eastham, D.A.; Thorn, R.

    1978-07-01

    Voltage tests on the Daresbury ceramic/titanium accelerator tube have shown that microdischarges play an important role in the conditioning process. It has been found that the voltage onset for microdischarges in a tube is dependent on the surface contamination of the electrodes and the tube geometry (in particular the tube length). This geometrical effect can be related to the trajectories of secondary ions emitted from the electrode surfaces. Sensitive diagnostic techniques have been developed to study the mass and energy distribution of ions emitted along the axis of the tube during these predischarges. The energy distribution of protons (and H - ions) can be related to the origins of the discharges in the tube. Detailed results are presented for a particular tube geometry. (author)

  8. Survey of Transmission Cost Allocation Methodologies for Regional Transmission Organizations

    Energy Technology Data Exchange (ETDEWEB)

    Fink, S.; Porter, K.; Mudd, C.; Rogers, J.

    2011-02-01

    The report presents transmission cost allocation methodologies for reliability transmission projects, generation interconnection, and economic transmission projects for all Regional Transmission Organizations.

  9. Ultrasonic inspection of tube to tube plate welds

    International Nuclear Information System (INIS)

    Telford, D.W.; Peat, T.S.

    1985-01-01

    To monitor the deterioration of a weld between a tube and tube plate which has been repaired by a repair sleeve inside the tube and brazed at one end to the tube, ultrasound from a crystal at the end of a rod is launched, in the form of Lamb-type waves, into the tube through the braze and allowed to travel along the tube to the weld and be reflected back along the tube. The technique may also be used for the type of heat exchanger in which, during construction, the tubes are welded to the tube plate via external sleeves in which case the ultrasound is used in a similar manner to inspect the sleeve/tube plate weld. an electromagnetic transducer may be used to generate the ultrasound. The ultrasonic head comprising the crystal and an acoustic baffle is mounted on a Perspex (RTM) rod which may be rotated by a stepping motor. Echo signals from the region of deterioration may be isolated by use of a time gate in the receiver. The device primarily detects circumferentially orientated cracks, and may be used in heat exchangers in nuclear power plants. (author)

  10. Liquid-Nitrogen Test for Blocked Tubes

    Science.gov (United States)

    Wagner, W. R.

    1984-01-01

    Nondestructive test identifies obstructed tube in array of parallel tubes. Trickle of liquid nitrogen allowed to flow through tube array until array accumulates substantial formation of frost from moisture in air. Flow stopped and warm air introduced into inlet manifold to heat tubes in array. Tubes still frosted after others defrosted identified as obstructed tubes. Applications include inspection of flow systems having parallel legs.

  11. YouTube, dentistry, and dental education.

    Science.gov (United States)

    Knösel, Michael; Jung, Klaus; Bleckmann, Annalen

    2011-12-01

    The objective of this study was to systematically assess the informational value, intention, source, and bias of videos related to dentistry available on the video-sharing Internet platform YouTube. YouTube (www.youtube.com) was searched for videos related to dentistry, using the system-generated sorts "by relevance" and "most viewed" and two categories (All and Education). Each of the first thirty results was rated by two assessors filling out a questionnaire for each (total: 120). The data were subjected to statistical analysis using Cohen's kappa, Pearson's correlation coefficient tau, Mann-Whitney U-tests, and a nonparametric three-way ANOVA, including an analysis of the interaction between the sorting and category effect, with an α-level of 5 percent. The scan produced 279,000 results in the category All and 5,050 in the category Education. The analysis revealed a wide variety of information about dentistry available on YouTube. The purpose of these videos includes entertainment, advertising, and education. The videos classified under Education have a higher degree of usefulness and informational value for laypersons, dental students, and dental professionals than those found in a broader search category. YouTube and similar social media websites offer new educational possibilities that are currently both underdeveloped and underestimated in terms of their potential value. Dentists and dental educators should also recognize the importance of these websites in shaping public opinion about their profession.

  12. Counteracting the Influence of Peer Smoking on YouTube

    OpenAIRE

    Romer, Daniel; Jamieson, Patrick E.; Jamieson, Kathleen Hall; Jones, Christopher; Sherr, Susan

    2017-01-01

    YouTube, a popular online site for user-generated content, is emerging as a powerful source of peer modeling of smoking. Previous research suggests that in counteracting such influence, health messages may inadvertently increase the perceived prevalence of drug use (a descriptive norm) without reducing its acceptability (injunctive norm). This research tested the ability of health messages to reduce the social acceptability of peer smoking on YouTube despite enhancing its perceived prevalence...

  13. Estimation and comparison of effective dose (E) in standard chest CT by organ dose measurements and dose-length-product methods and assessment of the influence of CT tube potential (energy dependency) on effective dose in a dual-source CT.

    Science.gov (United States)

    Paul, Jijo; Banckwitz, Rosemarie; Krauss, Bernhard; Vogl, Thomas J; Maentele, Werner; Bauer, Ralf W

    2012-04-01

    To determine effective dose (E) during standard chest CT using an organ dose-based and a dose-length-product-based (DLP) approach for four different scan protocols including high-pitch and dual-energy in a dual-source CT scanner of the second generation. Organ doses were measured with thermo luminescence dosimeters (TLD) in an anthropomorphic male adult phantom. Further, DLP-based dose estimates were performed by using the standard 0.014mSv/mGycm conversion coefficient k. Examinations were performed on a dual-source CT system (Somatom Definition Flash, Siemens). Four scan protocols were investigated: (1) single-source 120kV, (2) single-source 100kV, (3) high-pitch 120kV, and (4) dual-energy with 100/Sn140kV with equivalent CTDIvol and no automated tube current modulation. E was then determined following recommendations of ICRP publication 103 and 60 and specific k values were derived. DLP-based estimates differed by 4.5-16.56% and 5.2-15.8% relatively to ICRP 60 and 103, respectively. The derived k factors calculated from TLD measurements were 0.0148, 0.015, 0.0166, and 0.0148 for protocol 1, 2, 3 and 4, respectively. Effective dose estimations by ICRP 103 and 60 for single-energy and dual-energy protocols show a difference of less than 0.04mSv. Estimates of E based on DLP work equally well for single-energy, high-pitch and dual-energy CT examinations. The tube potential definitely affects effective dose in a substantial way. Effective dose estimations by ICRP 103 and 60 for both single-energy and dual-energy examinations differ not more than 0.04mSv. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  14. Tubing misconnections: normalization of deviance.

    Science.gov (United States)

    Simmons, Debora; Symes, Lene; Guenter, Peggi; Graves, Krisanne

    2011-06-01

    Accidental connection of an enteral system to an intravenous (IV) system frequently results in the death of the patient. Misconnections are commonly attributed to the presence of universal connectors found in the majority of patient care tubing systems. Universal connectors allow for tubing misconnections between physiologically incompatible systems. The purpose of this review of case studies of tubing misconnections and of current expert recommendations for safe tubing connections was to answer the following questions: In tubing connections that have the potential for misconnections between enteral and IV tubing, what are the threats to safety? What are patient outcomes following misconnections between enteral and IV tubing? What are the current recommendations for preventing misconnections between enteral and IV tubing? Following an extensive literature search and guided by 2 models of threats and errors, the authors analyzed case studies and expert opinions to identify technical, organizational, and human errors; patient-related threats; patient outcomes; and recommendations. A total of 116 case studies were found in 34 publications. Each involved misconnections of tubes carrying feedings, intended for enteral routes, to IV lines. Overwhelmingly, the recommendations were for redesign to eliminate universal connectors and prevent misconnections. Other recommendations were made, but the analysis indicates they would not prevent all misconnections. This review of the published case studies and current expert recommendations supports a redesign of connectors to ensure incompatibility between enteral and IV systems. Despite the cumulative evidence, little progress has been made to safeguard patients from tubing misconnections.

  15. Optimization of a neutron transmission beamline applied to materials science for the CAB linear accelerator

    International Nuclear Information System (INIS)

    Ramirez, S; Santisteban, J.R

    2009-01-01

    The Neutrons and Reactors Laboratory (NYR) of CAB (Centro Atomico Bariloche) is equipped with a linear electron accelerator (LINAC - Linear particle accelerator). This LINAC is used as a neutron source from which two beams are extracted to perform neutron transmission and dispersion experiments. Through these experiments, structural and dynamic properties of materials can be studied. The neutron transmission experiments consist in a collimated neutron beam which interacts with a sample and a detector behind the sample. Important information about the microstructural characteristics of the material can be obtained from the comparison between neutron spectra before and after the interaction with the sample. In the NYR Laboratory, cylindrical samples of one inch of diameter have been traditionally studied. Nonetheless, there is a great motivation for doing systematic research on smaller and with different geometries samples; particularly sheets and samples for tensile tests. Hence, in the NYR Laboratory it has been considered the possibility of incorporating a neutron guide into the existent transmission line. According to all mentioned above, the main objective of this work consisted in the optimization of the flight transmission tube optics of neutrons. This optimization not only improved the existent line but also contributed to an election criterion for the neutron guide acquisition. [es

  16. Associated-particle sealed-tube neutron generators and hodoscopes for NDA applications

    International Nuclear Information System (INIS)

    Rhodes, E.; Peters, C.W.

    1991-01-01

    With radioisotope sources, gamma-ray transmission hodoscopes can inspect canisters and railcars to monitor rocket motors, can detect nuclear warheads by their characteristic strong gamma-ray absorption, or can count nuclear warheads inside a missile by low-resolution tomography. Intrinsic gamma-ray radiation from warheads can also be detected in a passive mode. Neutron hodoscopes can use neutron transmission, intrinsic neutron emission, or reactions stimulated by a neutron source, in treaty verification roles. Gamma-ray and neutron hodoscopes can be combined with a recently developed neutron diagnostic probe system, based on a unique associated-particle sealed-tube neutron generator (APSTNG) that interrogates the object of interest with a low-intensity beam of 14-MeV neutrons, and that uses flight-time to electronically collimate transmitted neutrons and to tomographically image nuclides identified by reaction gamma-rays. Gamma-ray spectra of resulting neutron reactions identify nuclides associated with all major chemicals in chemical warfare agents, explosives, and drugs, as well as many pollutants and fissile and fertile special nuclear material. 5 refs., 12 figs

  17. A new sliding joint to accommodate recoil of a free-piston-driven expansion tube facility

    Science.gov (United States)

    Gildfind, D. E.; Morgan, R. G.

    2016-11-01

    This paper describes a new device to decouple free-piston driver recoil and its associated mechanical vibration from the acceleration tube and test section of The University of Queensland's X3 expansion tube. A sliding joint is introduced to the acceleration tube which axially decouples the facility at this station. When the facility is fired, the upstream section of the facility, which includes the free-piston driver, can recoil upstream freely. The downstream acceleration tube remains stationary. This arrangement provides two important benefits. Firstly, it eliminates nozzle movement relative to the test section before and during the experiment. This has benefits in terms of experimental setup and alignment. Secondly, it prevents transmission of mechanical disturbances from the free-piston driver to the acceleration tube, thereby eliminating mechanically-induced transducer noise in the sensitive pressure transducers installed in this low-pressure tube. This paper details the new design, and presents experimental confirmation of its performance.

  18. Vibration tests on single heat exchanger tubes in air and static water

    International Nuclear Information System (INIS)

    Collinson, A.E.; Warneford, I.P.

    1978-07-01

    The vibrational characteristics of a 7 span straight tube and a 26 span U-tube have been investigated for the effects of fluid medium (air/water), tube-grid clearance, tube-grid contact force, vibration transmission and scale. Measured frequency response and mode shapes compared favourably with theoretical values, vibration with pin-pin tube support being most readily excited. The frequency reduction on immersion in water corresponded to an added mass equivalent to the liquid displaced mass. Dynamic magnifiers varied in the range 12 to 135 with mean values of 30 to 40 in water and 45 to 60 in air. Principal vibration modes and damping values were reproducible in a half-scale model of a U-tube. (author)

  19. Estimation and comparison of effective dose (E) in standard chest CT by organ dose measurements and dose-length-product methods and assessment of the influence of CT tube potential (energy dependency) on effective dose in a dual-source CT

    International Nuclear Information System (INIS)

    Paul, Jijo; Banckwitz, Rosemarie; Krauss, Bernhard; Vogl, Thomas J.; Maentele, Werner; Bauer, Ralf W.

    2012-01-01

    Highlights: ► The dual-energy protocol delivers the lowest effective dose of the investigated protocols for standard chest CT examinations, thus enabling functional imaging (like dual-energy perfusion) and can produce weighted images without dose penalty. ► The high-pitch protocol goes along with a 16% increase in dose compared to the standard 120 kV protocol and thus should preferably be used in pediatric, acute care settings (e.g. pulmonary embolism, aortic dissection and the like) or restless patients. ► The difference in effective dose estimates between ICRP 60 and 103 is minimal. ► Tube potential definitely has an effect on estimates of effective dose. - Abstract: Purpose: To determine effective dose (E) during standard chest CT using an organ dose-based and a dose-length-product-based (DLP) approach for four different scan protocols including high-pitch and dual-energy in a dual-source CT scanner of the second generation. Materials and methods: Organ doses were measured with thermo luminescence dosimeters (TLD) in an anthropomorphic male adult phantom. Further, DLP-based dose estimates were performed by using the standard 0.014 mSv/mGycm conversion coefficient k. Examinations were performed on a dual-source CT system (Somatom Definition Flash, Siemens). Four scan protocols were investigated: (1) single-source 120 kV, (2) single-source 100 kV, (3) high-pitch 120 kV, and (4) dual-energy with 100/Sn140 kV with equivalent CTDIvol and no automated tube current modulation. E was then determined following recommendations of ICRP publication 103 and 60 and specific k values were derived. Results: DLP-based estimates differed by 4.5–16.56% and 5.2–15.8% relatively to ICRP 60 and 103, respectively. The derived k factors calculated from TLD measurements were 0.0148, 0.015, 0.0166, and 0.0148 for protocol 1, 2, 3 and 4, respectively. Effective dose estimations by ICRP 103 and 60 for single-energy and dual-energy protocols show a difference of less than 0.04 m

  20. Underground transmission tomography

    International Nuclear Information System (INIS)

    Geibka, C.

    1990-01-01

    Several underground tomographic transmission surveys have been carried out. Targets were cavities, ore veins and fault zones. Examples from measurements in a german heavy/fluor spar mine a lead/zinc mine and a rock laboratory of the Swiss National Cooperative for the Storage of Radioactive waste are presented. Measurements were carried out between boreholes and road ways. The recording equipment was the intrinsically safe SEAMEX85 system built and sold by WBK. Receivers were mounted in a chain of 6 two-component probes. Sources were an inhole hammer a sledge hammer a sparker and explosives from a single detonator to 180 g depending on the distance and absorption of the rock material. Cavities showed very distinct velocity reductions between 30 and 50%. Different vein material showed velocity reduction as well as velocity increase relative to the surrounding rock

  1. Steam generator tube integrity program

    International Nuclear Information System (INIS)

    Dierks, D.R.; Shack, W.J.; Muscara, J.

    1996-01-01

    A new research program on steam generator tubing degradation is being sponsored by the U.S. Nuclear Regulatory Commission (NRC) at Argonne National Laboratory. This program is intended to support a performance-based steam generator tube integrity rule. Critical areas addressed by the program include evaluation of the processes used for the in-service inspection of steam generator tubes and recommendations for improving the reliability and accuracy of inspections; validation and improvement of correlations for evaluating integrity and leakage of degraded steam generator tubes, and validation and improvement of correlations and models for predicting degradation in steam generator tubes as aging occurs. The studies will focus on mill-annealed Alloy 600 tubing, however, tests will also be performed on replacement materials such as thermally-treated Alloy 600 or 690. An overview of the technical work planned for the program is given

  2. Applicability and sensitivity of gamma transmission and radiotracer techniques for mineral scaling studies

    Energy Technology Data Exchange (ETDEWEB)

    Bjoernstad, Tor; Stamatakis, Emanuel

    2006-05-15

    Mineral scaling in petroleum and geothermal production systems creates a substantial problem of flow impairment. It is a priority to develop methods for scale inhibition. To study scaling rates and mechanisms in laboratory flow experiments under simulated reservoir conditions two nuclear methods have been introduced and tested. The first applies the principle of gamma transmission to measure mass increase. Here, we use a 30 MBq source of 133Ba. The other method applies radioactive tracers of one or more of the scaling components. We have used the study of CaC03-precipitation, as an example of the applicability of the method where the main tracer used is 47Ca2+. While the first method must be regarded as an indirect method, the latter is a direct method where the reactions of specific components may be studied. Both methods are on-line, continuous and non-destructive, and capable to study scaling of liquids with saturation ratios as low as SR=1.5 or lower. A lower limit of detection for the transmission method in sand-packed columns with otherwise reasonable experimental parameters is less than 1 mg CaC03 in a 1 cm section of the tube packed with silica sand SiO2. A lower limit of detection for the tracer method with reasonable experimental parameters is less than 1 microgram in the same tube section. (author) (tk)

  3. Broadband transmission noise reduction of smart panels featuring piezoelectric shunt circuits and sound-absorbing material.

    Science.gov (United States)

    Kim, Jaehwan; Lee, Joong-Kuen

    2002-09-01

    The possibility of a broadband noise reduction of piezoelectric smart panels is experimentally studied. A piezoelectric smart panel is basically a plate structure on which piezoelectric patches with electrical shunt circuits are mounted and sound-absorbing material is bonded on the surface of the structure. Sound-absorbing material can absorb the sound transmitted at the midfrequency region effectively while the use of piezoelectric shunt damping can reduce the transmission at resonance frequencies of the panel structure. To be able to reduce the sound transmission at low panel resonance frequencies, piezoelectric damping using the measured electrical impedance model is adopted. A resonant shunt circuit for piezoelectric shunt damping is composed of resistor and inductor in series, and they are determined by maximizing the dissipated energy through the circuit. The transmitted noise-reduction performance of smart panels is tested in an acoustic tunnel. The tunnel is a square cross-sectional tube and a loudspeaker is mounted at one side of the tube as a sound source. Panels are mounted in the middle of the tunnel and the transmitted sound pressure across panels is measured. When an absorbing material is bonded on a single plate, a remarkable transmitted noise reduction in the midfrequency region is observed except for the fundamental resonance frequency of the plate. By enabling the piezoelectric shunt damping, noise reduction is achieved at the resonance frequency as well. Piezoelectric smart panels incorporating passive absorbing material and piezoelectric shunt damping is a promising technology for noise reduction over a broadband of frequencies.

  4. Applicability and sensitivity of gamma transmission and radiotracer techniques for mineral scaling studies

    International Nuclear Information System (INIS)

    Bjoernstad, Tor; Stamatakis, Emanuel

    2006-05-01

    Mineral scaling in petroleum and geothermal production systems creates a substantial problem of flow impairment. It is a priority to develop methods for scale inhibition. To study scaling rates and mechanisms in laboratory flow experiments under simulated reservoir conditions two nuclear methods have been introduced and tested. The first applies the principle of gamma transmission to measure mass increase. Here, we use a 30 MBq source of 133Ba. The other method applies radioactive tracers of one or more of the scaling components. We have used the study of CaC03-precipitation, as an example of the applicability of the method where the main tracer used is 47Ca2+. While the first method must be regarded as an indirect method, the latter is a direct method where the reactions of specific components may be studied. Both methods are on-line, continuous and non-destructive, and capable to study scaling of liquids with saturation ratios as low as SR=1.5 or lower. A lower limit of detection for the transmission method in sand-packed columns with otherwise reasonable experimental parameters is less than 1 mg CaC03 in a 1 cm section of the tube packed with silica sand SiO2. A lower limit of detection for the tracer method with reasonable experimental parameters is less than 1 microgram in the same tube section. (author) (tk)

  5. Free compression tube. Applications

    Science.gov (United States)

    Rusu, Ioan

    2012-11-01

    During the flight of vehicles, their propulsion energy must overcome gravity, to ensure the displacement of air masses on vehicle trajectory, to cover both energy losses from the friction between a solid surface and the air and also the kinetic energy of reflected air masses due to the impact with the flying vehicle. The flight optimization by increasing speed and reducing fuel consumption has directed research in the aerodynamics field. The flying vehicles shapes obtained through studies in the wind tunnel provide the optimization of the impact with the air masses and the airflow along the vehicle. By energy balance studies for vehicles in flight, the author Ioan Rusu directed his research in reducing the energy lost at vehicle impact with air masses. In this respect as compared to classical solutions for building flight vehicles aerodynamic surfaces which reduce the impact and friction with air masses, Ioan Rusu has invented a device which he named free compression tube for rockets, registered with the State Office for Inventions and Trademarks of Romania, OSIM, deposit f 2011 0352. Mounted in front of flight vehicles it eliminates significantly the impact and friction of air masses with the vehicle solid. The air masses come into contact with the air inside the free compression tube and the air-solid friction is eliminated and replaced by air to air friction.

  6. Tube leak detector

    International Nuclear Information System (INIS)

    Morita, Bunji; Takamura, Koichi; Matsuda, Shigehiro; Kiyosawa, Shun-ichi; Asami, Toru; Yamada, Hiroshi; Naruse, Shin-ichi.

    1995-01-01

    The device of the present invention detects occurrence of leakage in a steam generator, a steam heating tube, or a heat exchanger of a nuclear power plant. Namely, an vibration sensor is disposed at the rear end of a rod-like supersonic resonance member. A node portion for the vibrations of the resonance member is held by a holding member and attached to a wall surface of a can such as a boiler. With such a constitution, the resonance member is resonated by supersonic waves generated upon leakage of the tube. The vibrations are measured by the vibration sensor at the rear end. Presence of leakage is detected by utilizing one or more of resonance frequencies. Since the device adopts a resonance phenomenon, a conduction efficiency of the vibrations is high, thereby enabling to detect leakage at high sensitivity. In addition, the supersonic wave resonance member has its top end directly protruded into a pressure vessel such as a boiler by using a metal or a ceramic which is excellent in heat and pressure resistance. Accordingly, the sound of leak can be detected efficiently. (I.S.)

  7. Shock tube Multiphase Experiments

    Science.gov (United States)

    Middlebrooks, John; Allen, Roy; Paudel, Manoj; Young, Calvin; Musick, Ben; McFarland, Jacob

    2017-11-01

    Shock driven multiphase instabilities (SDMI) are unique physical phenomena that have far-reaching practical applications in engineering and science. The instability is present in high energy explosions, scramjet combustors, and supernovae events. The SDMI arises when a multiphase interface is impulsively accelerated by the passage of a shockwave. It is similar in development to the Richtmyer-Meshkov (RM) instability however, particle-to-gas coupling is the driving mechanism of the SDMI. As particle effects such as lag and phase change become more prominent, the SDMI's development begins to significantly deviate from the RM instability. We have developed an experiment for studying the SDMI in our shock tube facility. In our experiments, a multiphase interface is created using a laminar jet and flowed into the shock tube where it is accelerated by the passage of a planar shockwave. The interface development is captured using CCD cameras synchronized with planar laser illumination. This talk will give an overview of new experiments conducted to examine the development of a shocked cylindrical multiphase interface. The effects of Atwood number, particle size, and a second acceleration (reshock) of the interface will be discussed.

  8. Pressure tube reactors

    International Nuclear Information System (INIS)

    Natori, Hisahide.

    1981-01-01

    Purpose: To improve the electrical power generation efficiency in a pressure tube reactor in which coolants and moderators are separated by feedwater heating with heat generated in heavy water and by decreasing the amount of steams to be extracted from the turbine. Constitution: A heat exchanger and a heavy water cooler are additionally provided to a conventional pressure tube reactor. The heat exchanger is disposed at the pre-stage of a low pressure feedwater heater series. High temperature heavy water heated in the core is passed through the primary side of the exchanger, while feedwater is passed through the secondary side. The cooler is disposed on the downstream of the heat exchanger in the flowing direction of the heavy water, in which heavy water from the heat exchanger is passed through the primary side and the auxiliary equipment cooling water is sent to the secondary side thereof. Accordingly, since extraction of heating steams is no more necessary, the steam can be used for the rotation of the turbine, and the electrical power generation efficiency can be improved. (Seki, T.)

  9. Performance of pressure tubes in CANDU reactors

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, D.; Griffiths, M.; Bickel, G.; Buyers, A.; Coleman, C.; Nordin, H.; St Lawrence, S. [Canadian Nuclear Laboratories, Chalk River, Ontario (Canada)

    2016-06-15

    by about a factor of 6, while K{sub IH} is only slightly reduced. The role of microstructure and trace elements in these behaviours is described. Pressure tubes exhibit elongation, diametral expansion, and sag. The deformation behaviour is a function of operating conditions and the material properties that vary from tube-to-tube and as a function of axial location. Semi-empirical predictive models have been developed to describe the deformation response of average tubes as a function of operating conditions. The effect of material variability on corrosion behaviour is less well defined compared with other properties but there are instances where tube orientation and ingot source can be identified as factors that have an effect on hydrogen pick-up. (author)

  10. Measurements of electrically exploded tubes

    International Nuclear Information System (INIS)

    Shearer, J.W.; Hartman, C.W.; Munger, R.H.; Gullickson, R.L.; Trimble, D.O.; Cheng, D.Y.

    1975-01-01

    The dynamics of electrically exploded tubes were investigated, principally by means of current measurements and flash x-ray pictures. The pinch effect was observed on the tube motion. Pileup of the imploding tube metal was seen on axis. An approximate analytical model can be roughly fitted to the data, but a more complete fit can be obtained with detailed numerical codes. Application of the results to the planning of future gas-embedded Z-pinch experiments is discussed. (U.S.)

  11. The Educational Potential of YouTube.

    Science.gov (United States)

    Godwin, Haley T; Khan, Murtaza; Yellowlees, Peter

    2017-12-01

    The objective of this paper was to examine the educational potential and effectiveness of a 3 min video clip of a simulation of schizophrenia published online at YouTube. Researchers examined the 267 public comments published on the video-sharing website YouTube over 8 years by viewers of a schizophrenia simulation video titled "virtual hallucinations" made in the Second Life game platform. Comments were independently categorized into six groupings, then cooperatively finalized, and qualitatively analyzed. The six categories of style of comments were "Emotional" (n = 76), "Identification" (n = 62), "Educational Interest" (n = 45), "Mocking/Displeased" (n = 36), "Game Interest" (n = 32), and "Other" (n = 25). Without any advertising or marketing by the creators, over 194,400 views of the video were recorded in 8 years, an average of about 1500 views per month. The use of YouTube with its viral marketing potential has created a vastly amplified reach for this educational offering that would otherwise have been impossible. Qualitative analysis of publically posted comments in response to the video, which were generally positive, has led to a greater understanding of public reactions to such educational offerings. YouTube videos are already a rich source of data for psychiatric researchers, and psychiatric educators should consider posting high quality video clips on publically available social media platforms such as YouTube in order to reduce public stigma about psychiatric disorders and patients.

  12. Failure analysis of boiler tube

    International Nuclear Information System (INIS)

    Mehmood, K.; Siddiqui, A.R.

    2007-01-01

    Boiler tubes are energy conversion components where heat energy is used to convert water into high pressure superheated steam, which is then delivered to a turbine for electric power generation in thermal power plants or to run plant and machineries in a process or manufacturing industry. It was reported that one of the tubes of a fire-tube boiler used in a local industry had leakage after the formation of pits at the external surface of the tube. The inner side of the fire tube was working with hot flue gasses with a pressure of 10 Kg/cm/sup 2/ and temperature 225 degree C. The outside of the tube was surrounded by feed water. The purpose of this study was to determine the cause of pits developed at the external surface of the failed boiler tube sample. In the present work boiler tube samples of steel grade ASTM AI61/ASTM A192 were analyzed using metallographic analysis, chemical analysis, and mechanical testing. It was concluded that the appearance of defects on the boiler tube sample indicates cavitation type corrosion failure. Cavitation damage superficially resembled pitting, but surface appeared considerably rougher and had many closely spaced pits. (author)

  13. Radiation-resistant camera tube

    International Nuclear Information System (INIS)

    Kuwahata, Takao; Manabe, Sohei; Makishima, Yasuhiro

    1982-01-01

    It was a long time ago that Toshiba launched on manufacturing black-and-white radiation-resistant camera tubes employing nonbrowning face-plate glass for ITV cameras used in nuclear power plants. Now in compliance with the increasing demand in nuclear power field, the Company is at grips with the development of radiation-resistant single color-camera tubes incorporating a color-stripe filter for color ITV cameras used under radiation environment. Herein represented are the results of experiments on characteristics of materials for single color-camera tubes and prospects for commercialization of the tubes. (author)

  14. YouTube and 'psychiatry'.

    Science.gov (United States)

    Gordon, Robert; Miller, John; Collins, Noel

    2015-12-01

    YouTube is a video-sharing website that is increasingly used to share and disseminate health-related information, particularly among younger people. There are reports that social media sites, such as YouTube, are being used to communicate an anti-psychiatry message but this has never been confirmed in any published analysis of YouTube clip content. This descriptive study revealed that the representation of 'psychiatry' during summer 2012 was predominantly negative. A subsequent smaller re-analysis suggests that the negative portrayal of 'psychiatry' on YouTube is a stable phenomenon. The significance of this and how it could be addressed are discussed.

  15. Bacterial Biofilms in Jones Tubes.

    Science.gov (United States)

    Ahn, Eric S; Hauck, Matthew J; Kirk Harris, Jonathan; Robertson, Charles E; Dailey, Roger A

    To investigate the presence and microbiology of bacterial biofilms on Jones tubes (JTs) by direct visualization with scanning electron microscopy and polymerase chain reaction (PCR) of representative JTs, and to correlate these findings with inflammation and/or infection related to the JT. In this study, prospective case series were performed. JTs were recovered from consecutive patients presenting to clinic for routine cleaning or recurrent irritation/infection. Four tubes were processed for scanning electron microscopy alone to visualize evidence of biofilms. Two tubes underwent PCR alone for bacterial quantification. One tube was divided in half and sent for scanning electron microscopy and PCR. Symptoms related to the JTs were recorded at the time of recovery. Seven tubes were obtained. Five underwent SEM, and 3 out of 5 showed evidence of biofilms (60%). Two of the 3 biofilms demonstrated cocci and the third revealed rods. Three tubes underwent PCR. The predominant bacteria identified were Pseudomonadales (39%), Pseudomonas (16%), and Staphylococcus (14%). Three of the 7 patients (43%) reported irritation and discharge at presentation. Two symptomatic patients, whose tubes were imaged only, revealed biofilms. The third symptomatic patient's tube underwent PCR only, showing predominantly Staphylococcus (56%) and Haemophilus (36%) species. Two of the 4 asymptomatic patients also showed biofilms. All symptomatic patients improved rapidly after tube exchange and steroid antibiotic drops. Bacterial biofilms were variably present on JTs, and did not always correlate with patients' symptoms. Nevertheless, routine JT cleaning is recommended to treat and possibly prevent inflammation caused by biofilms.

  16. Grooved tube plug rolls in

    International Nuclear Information System (INIS)

    Krausser, P.

    1991-01-01

    The removable plugs used to date by the Power Generation Group (KWU) of Siemens to seal defective steam generator tubes have a good track record. Their sealing principle is based on the elastic tensioning of three seal disks against the inside wall of the tube. Now a further removable plug is available -a roll-in plug with a metal-coated surface. It is particularly suitable for use in the roller-expanded zone of the tubes at the tube sheet. The plugs can be used in both Siemens-KWU steam generators and in steam generators manufactured in compliance with the guidelines of the ASME Code. (author)

  17. Gamma densitometer for measuring Pu density in fuel tubes

    International Nuclear Information System (INIS)

    Winn, W.G.

    1982-01-01

    A fuel-gamma-densitometer (FGD) has been developed to examine nondestructively the uniformity of plutonium in aluminum-clad fuel tubes at the Savannah River Plant (SRP). The monitoring technique is γ-ray spectroscopy with a lead-collimated Ge(Li) detector. Plutonium density is correlated with the measured intensity of the 208 keV γ-ray from 237 U (7d) of the 241 Pu (15y) decay chain. The FGD measures the plutonium density within 0.125- or 0.25-inch-diameter areas of the 0.133- to 0.183-inch-thick tube walls. Each measurement yields a density ratio that relates the plutonium density of the measured area to the plutonium density in normal regions of the tube. The technique was used to appraise a series of fuel tubes to be irradated in an SRP reactor. High-density plutonium areas were initially identified by x-ray methods and then examined quantitatively with the FGD. The FGD reliably tested fuel tubes and yielded density ratios over a range of 0.0 to 2.5. FGD measurements examined (1) nonuniform plutonium densities or hot spots, (2) uniform high-density patches, and (3) plutonium density distribution in thin cladding regions. Measurements for tubes with known plutonium density agreed with predictions to within 2%. Attenuation measurements of the 208-keV γ-ray passage through the tube walls agreed to within 2 to 3% of calculated predictions. Collimator leakage measurements agreed with model calculations that predicted less than a 1.5% effect on plutonium density ratios. Finally, FGD measurements correlated well with x-ray transmission and fluoroscopic measurements. The data analysis for density ratios involved a small correction of about 10% for γ-shielding within the fuel tube. For hot spot examinations, limited information for this correction dictated a density ratio uncertainty of 3 to 5%

  18. Learning from YouTube [Video Book

    Science.gov (United States)

    Juhasz, Alexandra

    2011-01-01

    YouTube is a mess. YouTube is for amateurs. YouTube dissolves the real. YouTube is host to inconceivable combos. YouTube is best for corporate-made community. YouTube is badly baked. These are a few of the things Media Studies professor Alexandra Juhasz (and her class) learned about YouTube when she set out to investigate what actually happens…

  19. Plasmodium vivax Transmission in Africa.

    Directory of Open Access Journals (Sweden)

    Rosalind E Howes

    2015-11-01

    Full Text Available Malaria in sub-Saharan Africa has historically been almost exclusively attributed to Plasmodium falciparum (Pf. Current diagnostic and surveillance systems in much of sub-Saharan Africa are not designed to identify or report non-Pf human malaria infections accurately, resulting in a dearth of routine epidemiological data about their significance. The high prevalence of Duffy negativity provided a rationale for excluding the possibility of Plasmodium vivax (Pv transmission. However, review of varied evidence sources including traveller infections, community prevalence surveys, local clinical case reports, entomological and serological studies contradicts this viewpoint. Here, these data reports are weighted in a unified framework to reflect the strength of evidence of indigenous Pv transmission in terms of diagnostic specificity, size of individual reports and corroboration between evidence sources. Direct evidence was reported from 21 of the 47 malaria-endemic countries studied, while 42 countries were attributed with infections of visiting travellers. Overall, moderate to conclusive evidence of transmission was available from 18 countries, distributed across all parts of the continent. Approximately 86.6 million Duffy positive hosts were at risk of infection in Africa in 2015. Analysis of the mechanisms sustaining Pv transmission across this continent of low frequency of susceptible hosts found that reports of Pv prevalence were consistent with transmission being potentially limited to Duffy positive populations. Finally, reports of apparent Duffy-independent transmission are discussed. While Pv is evidently not a major malaria parasite across most of sub-Saharan Africa, the evidence presented here highlights its widespread low-level endemicity. An increased awareness of Pv as a potential malaria parasite, coupled with policy shifts towards species-specific diagnostics and reporting, will allow a robust assessment of the public health

  20. TEM examination of irradiated zircaloy-2 pressure tube material

    International Nuclear Information System (INIS)

    Srivastava, D.; Tewari, R.; Dey, G.K.; Sharma, B.P.; Sah, D.N.; Banerjee, Suparna; Sahoo, K.C.

    2005-09-01

    In the present work, microstructure of the zircaloy-2 pressure tube material irradiated in the Indian Pressurized Heavy Water RAPP-1. Reactor (PHWR) has been examined for the first time using transmission electron microscope (TEM). The samples were obtained from a zircaloy-2 pressure tube, which had been in operation in the high flux region of Rajasthan Atomic Power Station Unit -1, for a period for 6.77 effective full power years (EFPYs) and expected to have a cumulative radiation damage of about 3 dpa. In this study irradiated microstructure has been characterized and compared it with the microstructure of the unirradiated pressure tube samples. The effect of irradiation on the hydriding behaviour is also studied. (author)

  1. Acoustic impedances of ear canals measured by impedance tube

    DEFF Research Database (Denmark)

    Ciric, Dejan; Hammershøi, Dorte

    2007-01-01

    During hearing sensitivity tests, the sound field is commonly generated by an earphone placed on a subject ear. One of the factors that can affect the sound transmission in the ear is the acoustic impedance of the ear canal. Its importance is related to the contribution of other elements involved...... in the transmission such as the earphone impedance. In order to determine the acoustic impedances of human ear canals, the standardized method for measurement of complex impedances used for the measurement of the audiometric earphone impedances is applied. It is based on the transfer function between two microphone...... locations in an impedance tube. The end of the tube representing the measurement plane is placed at the ear canal entrance. Thus, the impedance seen from the entrance inward is measured on 25 subjects. Most subjects participated in the previous measurement of the ratio between the pressures at the open...

  2. PS proton source

    CERN Multimedia

    1959-01-01

    The first proton source used at CERN's Proton Synchrotron (PS) which started operation in 1959. This is CERN's oldest accelerator still functioning today (2018). It is part of the accelerator chain that supplies proton beams to the Large Hadron Collider. The source is a Thonemann type. In order to extract and accelerate the protons at high energy, a high frequency electrical field is used (140Mhz). The field is transmitted by a coil around a discharge tube in order to maintain the gas hydrogen in an ionised state. An electrical field pulse, in the order of 15kV, is then applied via an impulse transformer between anode and cathode of the discharge tube. The electrons and protons of the plasma formed in the ionised gas in the tube, are then separated. Currents in the order of 200mA during 100 microseconds have benn obtained with this type of source.

  3. Tube to tube excursive instability - sensitivities and transients

    International Nuclear Information System (INIS)

    Brown, M.; Layland, M.W.

    1980-01-01

    A simple basic analysis of excursive instability in a boiler tube shows how it depends upon operating conditions and physical properties. A detailed mathematical model of an AGR boiler is used to conduct a steady state parameter sensitivity survey. It is possible from this basis to anticipate the effects of changes in operating conditions and changes in design parameters upon tube to tube stability. Dynamic responses of tubes operating near the stability threshold are examined using a mathematical model. Simulated excursions are triggered by imparting small abrupt pressure changes on the boiler inlet pressure. The influences of the magnitude of the pressure change, waterside friction factor and gas side coupling between tubes are examined. (author)

  4. Jose Cabrera (Zorita) tube examination

    International Nuclear Information System (INIS)

    Kuchirka, P.J.

    1986-01-01

    Jose Cabrera (Zorita) tube examination procedures are discussed. This plant continues to use phosphate water chemistry (sodium/phosphate ratio = 2.1). Three hot leg tube segments were pulled from the Jose Cabera (Zorita) plant in 1985. One tube had a field EC indication on the OD at the first tube support plate and the other two had field EC indications on their ID about 3 inches above the bottom of the tube sheet. All three tubes were initially sent to Battelle for preliminary NDE and decontamination. Segments of two tubes were sent to Westinghouse for destructive examination. The results of the laboratory eddy current and radiographic examinations are given. The results of the visual examinations are also given. The tube with OD indications was destructively examined and shallow intergranular pitting and intergranular attack, up to 2 mils deep, were found on the OD in the tube sheet region. Local areas of IGA, up to 5 mils deep, were found on the OD within the tube support plate region. A summary of this information together with supporting micrographs is given. It was hypothesized that a caustic crevice environment was the cause of this mild degradation. Shallow areas of thinning or wastage, up to 3 mils, were found just above the top of the tube sheet in the sludge pile region. Even more shallow wastage was found at the edges of support plate locations. This wastage is believed to be the remnant of early plant chemistry when a higher sodium/phosphate ratio and higher phosphate concentration were allowed

  5. Primary Fallopian Tube Carcinoma

    Directory of Open Access Journals (Sweden)

    Prasad K Shetty

    2011-01-01

    Full Text Available Primary Fallopian Tube Carcinoma (PFTC is rare and accounts for about 0.3% of all gynecologic cancers. Less than 1500 cases have been reported in the literature. It arises in postmenopausal women and typically presents with abdominal pelvic pain, vaginal bleeding and watery discharge. However, a correct diagnosis is rarely achieved preoperative, and in many cases, the diagnosis is made after incidental surgery for unrelated conditions commonly being ovarian carcinoma . Compared with ovarian carcinoma, PFTC more often presents at early stages, but it has a worse prognosis. PFTC is usually managed in the same manner as ovarian cancer. We report a case of Left PFTC that presented as Left ovarian mass, and we briefly review the literature.

  6. Pressure tube reactor

    International Nuclear Information System (INIS)

    Matsumoto, Tomoyuki; Fujino, Michihira.

    1980-01-01

    Purpose: To equalize heavy water flow distribution by providing a nozzle for externally injecting heavy water from a vibration preventive plate to the upper portion to feed the heavy water in a pressure tube reactor and swallowing up heavy water in a calandria tank to supply the heavy water to the reactor core above the vibration preventive plate. Constitution: A moderator injection nozzle is mounted on the inner wall of a calandria tank. Heavy water is externally injected above the vibration preventive plate, and heavy water in the calandria tank is swallowed up to supply the heavy water to the core reactor above the vibration preventive plate. Therefore, the heavy water flow distribution can be equalized over the entire reactor core, and the distribution of neutron absorber dissolved in the heavy water is equalized. (Yoshihara, H.)

  7. A New Resonance Tube

    Science.gov (United States)

    Bates, Alan

    2017-12-01

    The measurement of the speed of sound in air with the resonance tube is a popular experiment that often yields accurate results. One approach is to hold a vibrating tuning fork over an air column that is partially immersed in water. The column is raised and lowered in the water until the generated standing wave produces resonance: this occurs at the point where sound is perceived to have maximum loudness, or at the point where the amplitude of the standing wave has maximum value, namely an antinode. An antinode coincides with the position of the tuning fork, beyond the end of the air column, which consequently introduces an end correction. One way to minimize this end correction is to measure the distance between consecutive antinodes.

  8. Beam tube vacuum in future superconducting proton colliders

    International Nuclear Information System (INIS)

    Turner, W.

    1994-10-01

    The beam tube vacuum requirements in future superconducting proton colliders that have been proposed or discussed in the literature -- SSC, LHC, and ELN -- are reviewed. The main beam tube vacuum problem encountered in these machines is how to deal with the magnitude of gas desorption and power deposition by synchrotron radiation while satisfying resistivity, impedance, and space constraints in the cryogenic environment of superconducting magnets. A beam tube vacuum model is developed that treats photodesorption of tightly bound H, C, and 0, photodesorption of physisorbed molecules, and the isotherm vapor pressure of H 2 . Experimental data on cold tube photodesorption experiments are reviewed and applied to model calculations of beam tube vacuum performance for simple cold beam tube and liner configurations. Particular emphasis is placed on the modeling and interpretation of beam tube photodesorpiion experiments at electron synchrotron light sources. The paper also includes discussion of the constraints imposed by beam image current heating, the growth rate of the resistive wall instability, and single-bunch instability impedance limits

  9. Healthcare information on YouTube: A systematic review.

    Science.gov (United States)

    Madathil, Kapil Chalil; Rivera-Rodriguez, A Joy; Greenstein, Joel S; Gramopadhye, Anand K

    2015-09-01

    This article reviews the peer-reviewed literature addressing the healthcare information available on YouTube. Inclusion and exclusion criteria were determined, and the online databases PubMed and Web of Knowledge were searched using the search phrases: (1) YouTube* AND Health* and (2) YouTube* AND Healthcare*. In all, 18 articles were reviewed, with the results suggesting that (1) YouTube is increasingly being used as a platform for disseminating health information; (2) content and frame analysis were the primary techniques employed by researchers to analyze the characteristics of this information; (3) YouTube contains misleading information, primarily anecdotal, that contradicts the reference standards and the probability of a lay user finding such content is relatively high; (4) the retrieval of relevant videos is dependent on the search term used; and (5) videos from government organizations and professional associations contained trustworthy and high-quality information. YouTube is used as a medium for promoting unscientific therapies and drugs that are yet to be approved by the appropriate agencies and has the potential to change the beliefs of patients concerning controversial topics such as vaccinations. This review recognizes the need to design interventions to enable consumers to critically assimilate the information posted on YouTube with more authoritative information sources to make effective healthcare decisions. © The Author(s) 2014.

  10. A continuous acceleration tube of ions under 200 KV

    International Nuclear Information System (INIS)

    Mongodin, G.

    1954-01-01

    The realization of an Van de Graaff accelerator required, for the preliminary studies, the construction of a small proton accelerator, functioning at 200 kV in order to resolve some parasitic effects inherent to the accelerators tubes. The aim of this report is to describe the different organs of the accelerator tube, to explain the operating system and to encode their characteristics. The report first presents the ion source and the beam buncher permitting to inject in the accelerator tube particles of about 9 kV and very batched in a thin beam of circular section. Then the study explain the tube characteristics considered like optic system. A method to obtain precise calculation of particle trajectories is exposed. Aberrations of the system were discussed and balance of the currents on all electrodes inside the tube for different regimes of working were provided. The influence of the residual pressure in the tube were explained. The report finally ends on a part of the fundamental problem of the straining occurring inside the tubes accelerators under high tension. (M.B.) [fr

  11. Improper tube fixation causing a leaky cuff

    Directory of Open Access Journals (Sweden)

    Gupta Babita

    2010-01-01

    Full Text Available Leaking endotracheal tube cuffs are common problems in intensive care units. We report a case wherein the inflation tube was damaged by the adhesive plaster used for tube fixation and resulted in leaking endotracheal tube cuff. We also give some suggestions regarding the tube fixation and some remedial measures for damaged inflation system.

  12. Characterization of tube support alloys

    International Nuclear Information System (INIS)

    Vaia, A.R.

    1985-01-01

    The involvement and relationship of carbon steel corrosion products in the tube denting phenomenon promoted an intensive research effort to: 1) understand, reproduce, and arrest the denting process, and 2) evaluate alternative tube support materials to provide additional corrosion resistance. The paper summarizes a corrosion testing program for the verification of type 405 stainless steel under acid or all volatile treatment conditions

  13. Radioisotope study of Eustachian tube

    International Nuclear Information System (INIS)

    De Rossi, G.; Campioni, P.; Vaccaro, A.

    1988-01-01

    Radioisotope studies of Eustachian tube are suggested in the preoperative phase of tympanoplasty, in order to assess tubal drainage and secretion. The use of gamma camera fitted to a computer allowed the AA, to calculate some semi-quantitative parameters for an exact assessment of the radioactivity transit from the tympanic cass up to the pharyngeal cavity, throughout the Eustachian tube. (orig.) [de

  14. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... Amblyopia Listen NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia Animations Blindness Cataract Convergence ... is maintained by the NEI Office of Science Communications, Public Liaison, and Education. Technical questions about this ...

  15. Tubing Cutter is Activated Hydraulically

    Science.gov (United States)

    Mcsmith, D. G.; Richardson, J. I.

    1983-01-01

    Hydraulically-actuated tubing cutter severs tubing when operator squeezes handle grip. "Gooseneck" extension enables cutter to be used in areas where accessiblity is limited. Cutter has potential as flight-line tool and is useful in automobile and fire rescue work.

  16. Flaming on YouTube

    NARCIS (Netherlands)

    Moor, Peter J.; Heuvelman, A.; Verleur, R.

    2010-01-01

    In this explorative study, flaming on YouTube was studied using surveys of YouTube users. Flaming is defined as displaying hostility by insulting, swearing or using otherwise offensive language. Three general conclusions were drawn. First, although many users said that they themselves do not flame,

  17. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... Amaurosis Low Vision Refractive Errors Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded video for NEI YouTube Videos: Amblyopia NEI Home Contact Us A-Z Site Map NEI on Social Media Information in Spanish (Información en español) Website, ...

  18. Flowmeter with silicon flow tube

    NARCIS (Netherlands)

    Lammerink, Theodorus S.J.; Dijkstra, Marcel; Haneveld, J.; Lötters, Joost Conrad

    2009-01-01

    A flowmeter comprising a system chip with a silicon substrate provided on a carrier, in an opening whereof at least one silicon flow tube is provided for transporting a medium whose flow rate is to be measured, said tube having two ends that issue via a wall of the opening into channels coated with

  19. Improved guide tube bulge tool

    International Nuclear Information System (INIS)

    Vaill, R.E.; Phillips, W.D.

    1979-01-01

    A guide tube bulge tool for securing control rod guide tubes to a fuel assembly grid, includes a cylinder having several flexible tines each of which is equipped with a semispherical radially outwardly extending projection. A tapered ram fits into the cylinder so as to force the tines outwardly when the ram is pulled into the cylinder while supporting the other tines. (UK)

  20. Midwest Transmission Workshop II Summary

    Energy Technology Data Exchange (ETDEWEB)

    Kevin Bryan

    2002-12-05

    OAK-B135 After introductions of all participants, Abby Arnold, RESOLVE, reviewed the purpose of the meeting and the agenda. The purpose of the workshop was to share the results of the Midwest Independent System Operator (MISO) scenario development for wind and other fuel sources and the corresponding implications for transmission throughout the MISO control area. The workshop agenda is included in Attachment A.

  1. Simulation studies on Tube End Expansion of AA2014 Alloy Tubes

    Science.gov (United States)

    Venugopal, L.; Prasad, N. E. C.; Geeta Krishna, P.; Praveen, L.

    2018-03-01

    End forming is defined as forming the end of tubular forms either by inverting the tube or by expanding it. It finds application in many fields such as in automotive and aerospace sectors as power transmission elements, fuel lines, exhaust pipes etc. The main aim of the present work is to expand the AA2014 alloy tubes with different die sets without any fracture. Deform 2D software was used for performing simulations on expanding the tubes with different die set (punch) values having differed forming angles (α = 15°, 30° and 45°) and expansion ratios (rp/r0 = 1.39, 1.53 and 1.67). Experiments were also conducted and the results correlate with the simulation results. The results shows that for the punch having less cone angle (α) values the linear displacement is more rather than higher cone angles. But in the case of higher cone angles the radial displacement is more than the linear displacement.

  2. Space power transmission

    Energy Technology Data Exchange (ETDEWEB)

    Kuribayashi, Shizuma [Mitsubishi Heavy Industries, Ltd., Tokyo, (Japan)

    1989-10-05

    There being a conception to utilize solar energy by use of a space power station (SPS), a method to bring that universal grace to mankind is wireless energy transmission. The wireless energy transmission is regarded to be microwave transmission or laser beam transmission. The microwave transmission is to transmit 2.45GHz band microwave from the SPS to a receiving station on the ground to meet power demand on earth. The microwave, as small in attenuation in atmosphere and resistant against rain and cloud, is made candidate and, however, problematic in influence on organism, necessary large area of receiving antenna and many other points to be studied. While the laser transmission, as more convergent of beam than the microwave transmission, is advantageous with enabling the receiving area to be small and, however, disadvantageous with being not resistant against dust, rain and cloud, if used for the energy transmission between the space and earth. 2 refs., 2 figs.

  3. Transmission on Balance 2006

    International Nuclear Information System (INIS)

    2007-02-01

    Every year he Dutch Transmission System Operator (TSO) TenneT issues the title publication 'Transmission on Balance'. This report provides information about the main technical operating results in the past year.

  4. Study of the sealing performance of tubing adapters in gas-tight deep-sea water sampler

    Directory of Open Access Journals (Sweden)

    Huang Haocai

    2014-09-01

    Full Text Available Tubing adapter is a key connection device in Gas-Tight Deep-Sea Water Sampler (GTWS. The sealing performance of the tubing adapter directly affects the GTWS’s overall gas tightness. Tubing adapters with good sealing performance can ensure the transmission of seawater samples without gas leakage and can be repeatedly used. However, the sealing performance of tubing adapters made of different materials was not studied sufficiently. With the research discussed in this paper, the materials match schemes of the tubing adapters were proposed. With non-linear finite element contact analysis and sea trials in the South China Sea, it is expected that the recommended materials match schemes not only meet the requirements of tubing adapters' sealing performance but also provide the feasible options for the following research on tubing adapters in GTWS

  5. Study of the sealing performance of tubing adapters in gas-tight deep-sea water sampler

    Directory of Open Access Journals (Sweden)

    Haocai Huang

    2014-09-01

    Full Text Available Tubing adapter is a key connection device in Gas-Tight Deep-Sea Water Sampler (GTWS. The sealing performance of the tubing adapter directly affects the GTWS's overall gas tightness. Tubing adapters with good sealing performance can ensure the transmission of seawater samples without gas leakage and can be repeatedly used. However, the sealing performance of tubing adapters made of different materials was not studied sufficiently. With the research discussed in this paper, the materials match schemes of the tubing adapters were proposed. With non-linear finite element contact analysis and sea trials in the South China Sea, it is expected that the recommended materials match schemes not only meet the requirements of tubing adapters’ sealing performance but also provide the feasible options for the following research on tubing adapters in GTWS.

  6. HF electronic tubes. Technologies, grid tubes and klystrons

    International Nuclear Information System (INIS)

    Lemoine, Th.

    2009-01-01

    This article gives an overview of the basic technologies of electronic tubes: cathodes, electronic optics, vacuum and high voltage. Then the grid tubes, klystrons and inductive output tubes (IOT) are introduced. Content: 1 - context and classification; 2 - electronic tube technologies: cathodes, electronic optics, magnetic confinement (linear tubes), periodic permanent magnet (PPM) focussing, collectors, depressed collectors; 3 - vacuum technologies: vacuum quality, surface effects and interaction with electrostatic and RF fields, secondary emission, multipactor effect, thermo-electronic emission; 4 - grid tubes: operation of a triode, tetrodes, dynamic operation and classes of use, 'common grid' and 'common cathode' operation, ranges of utilisation and limitations, operation of a tetrode on unadjusted load, lifetime of a tetrode, uses of grid tubes; 5 - klystrons: operation, impact of space charge, multi-cavity klystrons, interaction efficiency, extended interaction klystrons, relation between interaction efficiency, perveance and efficiency, ranges of utilization and power limitations, multi-beam klystrons and sheet beam klystrons, operation on unadjusted load, klystron band pass and lifetime, uses; 6 - IOT: principle of operation, ranges of utilisation and limitations, interaction efficiency and depressed collector IOT, IOT lifetime and uses. (J.S.)

  7. The biofilm-controlling functions of rechargeable antimicrobial N-halamine dental unit waterline tubing.

    Science.gov (United States)

    Porteous, Nuala; Schoolfield, John; Luo, Jie; Sun, Yuyu

    2011-01-01

    A study was conducted to test the biofilm-controlling functions of N-halamine tubing over an eight-month period. A laboratory system, simulating a teaching dental clinic, was used to test rechargeable N-halamine tubing (T) compared to an untreated control (C) using the unit manufacturer's tubing. For the long-term study, a recharged tubing (RC) treated with bleach was used to compare with the test (T) and the control (C) tubing. Source tap water was cycled through the lines at 1.4 mL/minute, five minutes on and 25 minutes off, eight hours/day, five days/week. Every three weeks, samples of effluent, recovered adherent bacteria from inside tubing surfaces, and SEM images were examined for bacterial and biofilm growth. After sampling, a recharging solution of chlorine bleach (1 : 10 dilution) was run through T and RC lines, left overnight, and rinsed out the next morning. One-way ANOVAs and Spearman correlations were performed to detect significant differences for T, RC, and C, and determine significance with time period and source water, respectively. Mean log CFU/mL for C effluent > T (p = 0.028), and C tubing > T (p = 0.035). Spearman correlations were significant between effluent and source water level for T (rho = 0.817), and T tubing (0.750); between RC tubing and source water level (rho = 0.836), and time (rho = 0.745); and between C and time (rho = 0.873). SEM imaging confirmed the presence of biofilm inside RC and C, but not inside T. N-halamine tubing completely inhibited biofilm formation without negatively affecting the physical properties of the effluent water. Further research on N-halamine tubing using a pure water source is recommended, as T effluent bacterial levels reflected the source tap water quality and proliferation of planktonic bacteria with no biofilm activity.

  8. Neural Tube Defects

    Science.gov (United States)

    ... March of Dimes Premature Birth Report Card Grades Cities, Counties; Focuses on Racial and Ethnic Disparities March ... folate. Good sources of folate are: Beans Leafy green vegetables Orange juice You have to eat a ...

  9. Space-Qualified Traveling-Wave Tube

    Science.gov (United States)

    Wilson, Jeffrey D.; Krawczyk, Richard; Simons, Rainee N.; Williams, Wallace D.; Robbins, Neal R.; Dibb, Daniel R.; Menninger, William L.; Zhai, Xiaoling; Benton, Robert T.

    2010-01-01

    The L-3 Communications Electron Technologies, Inc. Model 999HA traveling-wave tube (TWT), was developed for use as a high-power microwave amplifier for high-rate transmission of data and video signals from deep space to Earth (see figure). The 999HA is a successor to the 999H a non-space qualified TWT described in High-Power, High-Efficiency Ka-Band Traveling-Wave Tube (LEW-17900-1), NASA Tech Briefs, Vol. 31, No. 2 (February 2007), page 32. Operating in the 31.8-to-32.3 GHz frequency band, the 999HA has been shown to generate 252 W of continuous- wave output power at 62 percent overall power efficiency a 75-percent increase in output power over the 999H. The mass of the 999HA is 35 percent less than that of the 999H. Moreover, taking account of the elimination of a Faraday cage that is necessary for operation of the 999H but is obviated by a redesign of high-voltage feed-throughs for the 999HA, the overall reduction in mass becomes 57 percent with an 82 percent reduction in volume. Through a series of rigorous tests, the 999HA has been qualified for operation aboard spacecraft with a lifetime exceeding seven years. Offspring of the 999HA will fly on the Kepler and Lunar Reconnaissance Orbiter missions.

  10. Laboratory source based full-field x-ray microscopy at 9 keV

    Energy Technology Data Exchange (ETDEWEB)

    Fella, C.; Balles, A.; Wiest, W. [Lehrstuhl für Röntgenmikroskopie, Julius-Maximilians-Universität, 97074 Würzburg (Germany); Zabler, S.; Hanke, R. [Lehrstuhl für Röntgenmikroskopie, Julius-Maximilians-Universität, 97074 Würzburg (Germany); Fraunhofer Development Center X-Ray Technology (EZRT), Flugplatzstrasse 75, 90768 Fürth (Germany)

    2016-01-28

    In the past decade, hard x-ray transmission microscopy experienced tremendous developments. With the avail-ability of efficient Fresnel zone plates, even set-ups utilizing laboratory sources were developed [1]. In order to improve the performance of these x-ray microscopes, novel approaches to fabricate optical elements [2] and brighter x-ray tubes [3] are promising candidates. We are currently building a laboratory transmission x-ray microscope for 9.25 keV, using an electron impact liquid-metal-jet anode source. Up to now, the further elements of our setup are: a polycapillary condenser, a tungsten zone plate, and a scintillator which is optically coupled to a CMOS camera. However, further variations in terms of optical elements are intended. Here we present the current status of our work, as well as first experimental results.

  11. Water-storage-tube systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hemker, P.

    1981-12-24

    Passive solar collection/storage/distribution systems were surveyed, designed, fabricated, and mechanically and thermally tested. The types studied were clear and opaque fiberglass tubes, metal tubes with plastic liners, and thermosyphoning tubes. (MHR)

  12. Conditioning and breakdown phenomena in accelerator tubes

    International Nuclear Information System (INIS)

    Skorka, S.J.

    1979-01-01

    Important breakdown mechanisms in accelerator tubes are reviewed, and discharge phenomena in NEC tubes are deduced from the surface appearance of the electrodes and insulators of a used tube. Microphotos of these surfaces are shown

  13. Inspection from outside of weld bead on tubes by gamma absorptiometry

    International Nuclear Information System (INIS)

    Heintz, L.; Lefevre, C.; Bergey, C.

    1983-07-01

    In this method used when it is impossible to place the gamma source inside the tube, the gamma rays pass through the tube twice. The thickness of the weld bead is determined by only one coordinate of space: the polar angle in the plane of the weld. The method was tested with an uranium ring with machined defects. The position of the defects was determined with an accuracy of 1 degree and resolution is of the order of the tube thickness [fr

  14. YouTube Enhanced Case Teaching in Health Management and Policy

    Directory of Open Access Journals (Sweden)

    Jeremy C. Green

    2018-03-01

    Discussion: YouTube videos can be a valuable source of content to supplement existing case teaching materials in health management and policy. More research is needed to distinguish the effects of YouTube videos from other case teaching materials and flipped format aspects of course design. The general method of YouTube enhanced case teaching might be expanded beyond health management and policy to other topics in health professions education.

  15. Pressure tube reactor

    International Nuclear Information System (INIS)

    Kanazawa, Nobuhiro; Kaneto, Kunikazu.

    1979-01-01

    Purpose: To attain uniform fluid poison distribution in a calandria tank by downwardly projecting, at an equal distance to the reactor core, a spacer wall from the periphery of an anti-vibration plate in the vicinity of a heavy water flow passage in the periphery of the anti-vibration plate, thereby decrease the amount of heavy water flowing into the heavy water flow passage. Constitution: A projecting wall concentrical with a calandria tank is suspended vertically from the boundary side at the peripheral portion of an anti-vibration plate to a water heavy flow passage in the periphery of the anti-vibration plate. The projecting wall has such a vertical length as about equal to the width of the heavy water flow passage, prevents heavy water flowing through apertures of a control rod guide tube from entering into the heavy water passage and increases the ratio of heavy water that flows through the heavy water flow passage in the anti-vibration plate. Consequently, if the liquid poison density in heavy water is varied, the ununiform poison density in the calandria tank can be prevented. (Seki, T.)

  16. Compact microwave ion source

    International Nuclear Information System (INIS)

    Leung, K.N.; Walther, S.; Owren, H.W.

    1985-05-01

    A small microwave ion source has been fabricated from a quartz tube with one end enclosed by a two grid accelerator. The source is also enclosed by a cavity operated at a frequency of 2.45 GHz. Microwave power as high as 500 W can be coupled to the source plasma. The source has been operated with and without multicusp fields for different gases. In the case of hydrogen, ion current density of 200 mA/cm -2 with atomic ion species concentration as high as 80% has been extracted from the source

  17. The automotive transmission book

    CERN Document Server

    Fischer, Robert; Jürgens, Gunter; Najork, Rolf; Pollak, Burkhard

    2015-01-01

    This book presents essential information on systems and interactions in automotive transmission technology and outlines the methodologies used to analyze and develop transmission concepts and designs. Functions of and interactions between components and subassemblies of transmissions are introduced, providing a basis for designing transmission systems and for determining their potentials and properties in vehicle-specific applications: passenger cars, trucks, buses, tractors, and motorcycles. With these fundamentals the presentation provides universal resources for both state-of-the-art and future transmission technologies, including systems for electric and hybrid electric vehicles.

  18. Corium Configuration and Penetration Tube Failure for Fukushima Daiichi Nuclear Power Plant

    International Nuclear Information System (INIS)

    An, Sang Mo; Lee, Jae Bong; Kim, Hwan Yeol; Song, Jin Ho

    2016-01-01

    For the LWRs (light water reactors), the penetration tubes at the reactor vessel lower head are regarded as the most vulnerable structures along with a global vessel failure during a severe accident because they can be seriously damaged by a corium melt or debris relocated into the lower plenum of the vessel. The research on the penetration tube failure is of higher importance in the BWRs, as it could lead to melt discharge into the containment and subsequent release of radioactive materials to the environment due to the containment failure. There are more than one hundred of penetration tubes in the Fukushima Daiichi NPPs (nuclear power plants), such as ICM-GTs (in-core monitoring guide tubes), CRGTs (control rod guide tubes) and drain tubes. The ICM-GTs include SRMs (source range monitors), IRMs (intermediate range monitors), LPRMs (local power range monitors) and TIPs (traversing in-core probes), which are much thinner than other tubes. The experimental researches to investigate the corium configuration and the penetration tube failure for the Fukushima Daiichi NPPs were introduced and some meaningful results were summarized. It was shown that the corium ingot was separated into two layers, of which the upper layer was metal-rich while the lower one was oxide-rich. It seemed that B 4 C would contribute to reducing the density of the metallic melt. The two-layered configuration will provide useful information to understand the core melt progression and post-recovery actions for the Fukushima Daiichi NPPs. In addition, we performed a large scale penetration tube failure experiment for the SRM/IRM guide tube, and showed high possibilities of large amount of corium discharge out of the reactor vessel lower head, which followed by the tube melting in a very short time. We are planning to perform the penetration tube failure experiments for another dry tube of ICM-GT (LPRM guide tube), and later for the wet tube (CRGT)

  19. Corium Configuration and Penetration Tube Failure for Fukushima Daiichi Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    An, Sang Mo; Lee, Jae Bong; Kim, Hwan Yeol; Song, Jin Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    For the LWRs (light water reactors), the penetration tubes at the reactor vessel lower head are regarded as the most vulnerable structures along with a global vessel failure during a severe accident because they can be seriously damaged by a corium melt or debris relocated into the lower plenum of the vessel. The research on the penetration tube failure is of higher importance in the BWRs, as it could lead to melt discharge into the containment and subsequent release of radioactive materials to the environment due to the containment failure. There are more than one hundred of penetration tubes in the Fukushima Daiichi NPPs (nuclear power plants), such as ICM-GTs (in-core monitoring guide tubes), CRGTs (control rod guide tubes) and drain tubes. The ICM-GTs include SRMs (source range monitors), IRMs (intermediate range monitors), LPRMs (local power range monitors) and TIPs (traversing in-core probes), which are much thinner than other tubes. The experimental researches to investigate the corium configuration and the penetration tube failure for the Fukushima Daiichi NPPs were introduced and some meaningful results were summarized. It was shown that the corium ingot was separated into two layers, of which the upper layer was metal-rich while the lower one was oxide-rich. It seemed that B{sub 4}C would contribute to reducing the density of the metallic melt. The two-layered configuration will provide useful information to understand the core melt progression and post-recovery actions for the Fukushima Daiichi NPPs. In addition, we performed a large scale penetration tube failure experiment for the SRM/IRM guide tube, and showed high possibilities of large amount of corium discharge out of the reactor vessel lower head, which followed by the tube melting in a very short time. We are planning to perform the penetration tube failure experiments for another dry tube of ICM-GT (LPRM guide tube), and later for the wet tube (CRGT)

  20. Final Scientific/Technical Report "Arc Tube Coating System for Color Consistency"

    Energy Technology Data Exchange (ETDEWEB)

    Buelow, Roger [Energy Focus, Inc., Solon, OH (United States); Jenson, Chris [Energy Focus, Inc., Solon, OH (United States); Kazenski, Keith [Energy Focus, Inc., Solon, OH (United States)

    2013-03-21

    DOE has enabled the use of coating materials using low cost application methods on light sources to positively affect the output of those sources. The coatings and light source combinations have shown increased lumen output of LED fixtures (1.5%-2.0%), LED arrays (1.4%) and LED powered remote phosphor systems Philips L-Prize lamp (0.9%). We have also demonstrated lifetime enhancements (3000 hrs vs 8000 hrs) and shifting to higher CRI (51 to 65) in metal halide high intensity discharge lamps with metal oxide coatings. The coatings on LEDs and LED products are significant as the market is moving increasingly more towards LED technology. Enhancements in LED performance are demonstrated in this work through the use of available materials and low cost application processes. EFOI used low refractive index fluoropolymers and low cost dipping processes for application of the material to surfaces related to light transmission of LEDs and LED products. Materials included Teflon AF, an amorphous fluorinated polymer and fluorinated acrylic monomers. The DOE SSL Roadmap sets goals for LED performance moving into the future. EFOI's coating technology is a means to shift the performance curve for LEDs. This is not limited to one type of LED, but is relevant across LED technologies. The metal halide work included the use of sol-gel solutions resulting in silicon dioxide and titanium dioxide coatings on the quartz substrates of the metal halide arc tubes. The coatings were applied using low cost dipping processes.

  1. Internal heat exchange tubes for industrial furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Hoetzl, M.; Lingle, T.M.

    1992-05-26

    This patent describes a method for cooling the work within an industrial furnace. It comprises providing a longitudinally extending outer tube which extends into the furnace having a closed axial end and an open axial end; providing a preformed inner tube open at both ends within the outer tube; injecting a coolant into the inner tube so that the coolant flows from one axial end of the tube out the opposite end adjacent the closed end of the outer tube, and from the closed end of the outer tube to the open end thereof; circulating a gas within the furnace against the outer tube to effect heat transfer therewith.

  2. Patient identification and tube labelling

    DEFF Research Database (Denmark)

    van Dongen-Lases, Edmée C; Cornes, Michael P; Grankvist, Kjell

    2016-01-01

    of phlebotomy procedures with the CLSI H3-A6 guideline was unacceptably low, and that patient identification and tube labelling are amongst the most critical steps in need of immediate attention and improvement. The process of patient identification and tube labelling is an essential safety barrier to prevent...... patient identity mix-up. Therefore, the EFLM Working Group aims to encourage and support worldwide harmonisation of patient identification and tube labelling procedures in order to reduce the risk of preanalytical errors and improve patient safety. With this Position paper we wish to raise awareness...... and provide recommendations for proper patient and sample identification procedures....

  3. PEG tubes: dealing with complications.

    Science.gov (United States)

    Malhi, Hardip; Thompson, Rosie

    A percutaneous endoscopic gastronomy tube can be used to deliver nutrition, hydration and medicines directly into the patient's stomach. Patients will require a tube if they are unable to swallow safely, putting them at risk of aspiration of food, drink and medicines into their lungs. It is vital that nurses are aware of the complications that may arise when caring for a patient with a PEG tube. It is equally important that nurses know how to deal with these complications or from where tc seek advice. This article provides a quick troubleshooting guide to help nurses deal with complications that can arise with PEG feeding.

  4. Applications of liquid scintillation tubes

    International Nuclear Information System (INIS)

    Broga, D.W.

    1977-01-01

    A new cocktail containing device for liquid scintillation counting, the scintillation tube, consists of a two-layered plastic bag which is heatsealed after the cocktail and sample have been placed in it. It is then placed in a carrying vial and counted in a conventional liquid scintillation counter. These tubes have proved to be a practical and economical alternative to vials. Some of their advantages are elimination of absorption problems, transparency, lower background and higher counting efficiency, low breakage danger and savings in waste disposal costs. Two applications for which the tubes are particularly suitable are the counting of laboratory swipes and urine analysis. (author)

  5. Pellicle transmission uniformity requirements

    Science.gov (United States)

    Brown, Thomas L.; Ito, Kunihiro

    1998-12-01

    Controlling critical dimensions of devices is a constant battle for the photolithography engineer. Current DUV lithographic process exposure latitude is typically 12 to 15% of the total dose. A third of this exposure latitude budget may be used up by a variable related to masking that has not previously received much attention. The emphasis on pellicle transmission has been focused on increasing the average transmission. Much less, attention has been paid to transmission uniformity. This paper explores the total demand on the photospeed latitude budget, the causes of pellicle transmission nonuniformity and examines reasonable expectations for pellicle performance. Modeling is used to examine how the two primary errors in pellicle manufacturing contribute to nonuniformity in transmission. World-class pellicle transmission uniformity standards are discussed and a comparison made between specifications of other components in the photolithographic process. Specifications for other materials or parameters are used as benchmarks to develop a proposed industry standard for pellicle transmission uniformity.

  6. Imaging of the Eustachian tube and its function: a systematic review

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.E.; Tysome, J.R. [Cambridge University Hospitals NHS Foundation Trust, Department of ENT Surgery, Addenbrooke' s Hospital, Cambridge (United Kingdom); Scoffings, D.J. [Cambridge University Hospitals NHS Foundation Trust, Department of Radiology, Addenbrooke' s Hospital, Cambridge (United Kingdom)

    2016-06-15

    The Eustachian tube is a complex and inaccessible structure, which maintains middle ear ventilation to facilitate transmission of sound from the tympanic membrane to the cochlea. A renewed interest in treatments for eustachian tube dysfunction has led to a demand for methods of imaging the Eustachian tube, and assessing tube opening non-invasively. This review aims to summarise the use of imaging in the anatomical assessment of the Eustachian tube, and to explore how radiological techniques can be used to assess tube function. A systematic review of the literature was performed with narrative data analysis. With high-resolution images, the soft and bony anatomy of the Eustachian tube can be assessed in detail. CT and MRI are best suited to identifying features associated with obstructive or patulous Eustachian tube dysfunction, though true assessments of function have only been achieved with contrast enhanced radiographs and scintigraphy. A single modality has yet to provide a complete assessment. No test has entered routine clinical use, but further development and research is underway. Significant information can be gained from imaging the Eustachian tube, and as faster acquisition techniques are developed, it is possible that dynamic imaging of tubal opening could play an important role in the assessment of patients with ET dysfunction. (orig.)

  7. Effects of Two Purification Pretreatments on Electroless Copper Coating over Single-Walled Carbon Nano tubes

    International Nuclear Information System (INIS)

    Zheng, Z.; Li, L.; Dong, Sh.; Li, Sh.; Xiao, A.; Sun, Sh.

    2014-01-01

    To achieve the reinforcement of copper matrix composite by single-walled carbon nano tubes, a three-step-refluxing purification of carbon nano tubes sample with HNO 3 -NaOH-HCl was proposed and demonstrated. A previously reported purification process using an electromagnetic stirring with H 2 O 2 /HCl mixture was also repeated. Then, the purified carbon nano tubes were coated with copper by the same electroless plating process. At the end, the effects of the method on carbon nano tubes themselves and on copper coating were determined by transmission electron microscope spectroscopy, scanning electron microscope spectroscopy, X-ray diffractometry, thermogravimetric analysis, Fourier transformed infrared spectroscopy, and energy dispersive spectrometry. It was clearly confirmed that both of the two processes could remove most of iron catalyst particles and carbonaceous impurities without significant damage to carbon nano tubes. The thermal stability of the sample purified by H 2 O 2 /HCl treatment was slightly higher than that purified by HNO 3 -NaOH-HCl treatment. Nevertheless, the purification by HNO 3 -NaOH-HCl treatment was more effective for carboxyl functionalization on nano tubes than that by H 2 O 2 /HCl treatment. The Cu-coating on carbon nano tubes purified by both purification processes was complete, homogenous, and continuous. However, the Cu-coating on carbon nano tubes purified by H 2 O 2 /HCl was oxidized more seriously than those on carbon nano tubes purified by HNO 3 -NaOH-HCl treatment.

  8. Lyme Disease Transmission

    Science.gov (United States)

    ... not known to transmit Lyme disease include Lone star ticks ( Amblyomma americanum ), the American dog tick ( Dermacentor ... of Vector-Borne Diseases (DVBD) Email Recommend Tweet YouTube Instagram Listen Watch RSS ABOUT About CDC Jobs ...

  9. Condenser tube buckling within tube-tubesheet joints

    International Nuclear Information System (INIS)

    Willertz, L.E.; Kalnins, A.; Updike, D.P.

    1991-01-01

    The problem of the appearance of protrusions, or bumps, in the interior of roller-expanded tubes within a tubesheet is addressed. Such bumps have been observed in condensers of power plants. A brief history of the reported occurrences of the bumps is given. The hypothesis is advanced that the mechanics of the formation of the bumps is similar to a buckling problem that has 'bifurcation at infinity'. Following this hypothesis, a two-dimensional physical model is developed, and the application of this model to study a three-dimensional bump is proposed. It is proposed in this paper that an initial deviation from the circular shape of the tube required to produce a bump. It is shown that without such a deviation the tubes cannot buckle. An experiment with short tube segments has been performed that verifies some of the features of the observed condenser tube bumps. Exactly what force produced the initial deviation for the observed bumps is still unknown. Available evidence implicates the hydro-laser jet that is used in the cleaning of tubes and tubesheets. A scenario of how a bump could have been produced by the hydro-laser jet is proposed. (author)

  10. Synthesis of barium-strontium titanate hollow tubes using Kirkendall effect

    Science.gov (United States)

    Chen, Xuncai; Im, SangHyuk; Kim, Jinsoo; Kim, Woo-Sik

    2018-02-01

    (BaSr)TiO3 hexagonal hollow tubes was fabricated by a solid-state interfacial reaction including a Kirkendall diffusion. Using a co-precipitation and sol-gel process, a core@shell structure of (BaSr)CO3@TiO2 rods were prepared, and then converted to (BaSr)TiO3 hollow tubes at 750 °C. This was a first achievement of single-phase crystal hollow tube. Here, the inner diameter and wall thickness of hollow tube were about 700 nm and 130 nm, respectively. The fabrication of (BaSr)TiO3 hollow tubes was monitored with scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), transmission electron microscopy (TEM), and X-ray diffraction (XRD) to investigate their formation mechanism. The present synthetic approach would provide a new insight into the design and fabrication of hollow architectures of many perovskite oxides.

  11. Macedonian transmission grid capability and development

    International Nuclear Information System (INIS)

    Naumoski, K.; Achkoska, E.; Paunoski, A.

    2015-01-01

    The main task of the transmission grid is to guarantee evacuation of electricity from production facilities and, at the same time, supply the electricity to all customers, in a secure, reliable and qualitative manner. During the last years, transmission grid goes through the period of fast and important development, as a result of implementation of renewable and new technologies and creation of internal European electricity market. Due to these reasons, capacity of the existing grid needs to be upgraded either with optimization of existing infrastructure or constructing the new transmission projects. Among the various solutions for strengthening the grid, the one with the minimal investment expenses for construction is selected. While planning the national transmission grid, MEPSO planners apply multi-scenarios analyses, in order to handle all uncertainties, particularly in the forecasts on loads, production and exchange of electricity, location and size of the new power plants, hydrological conditions, integration of renewable sources and the evolution of the electricity market. Visions for development of European transmission grid are also considered. Special attention in the development plan is paid to modelling of power systems in the region of South-Eastern Europe and covering a wider area of the regional transmission grid with simulations of various market transactions. Macedonian transmission grid is developed to satisfy all requirements for electricity production/supply and transits, irrespective which scenario will be realized on long-term basis. Transmission development plan gives the road map for grid evolution from short-term and mid-term period towards long-term horizons (15-20 years ahead). While creating long-term visions, a big challenge in front of transmission planners is implementation of NPP. The paper gives overview of the planning process of Macedonian transmission grid,comprising: definition of scenarios,planning methodology and assessment of

  12. Vibration isolation in a free-piston driven expansion tube facility

    Science.gov (United States)

    Gildfind, D. E.; Jacobs, P. A.; Morgan, R. G.

    2013-09-01

    The stress waves produced by rapid piston deceleration are a fundamental feature of free-piston driven expansion tubes, and wave propagation has to be considered in the design process. For lower enthalpy test conditions, these waves can traverse the tube ahead of critical flow processes, severely interfering with static pressure measurements of the passing flow. This paper details a new device which decouples the driven tube from the free-piston driver, and thus prevents transmission of stress waves. Following successful incorporation of the concept in the smaller X2 facility, it has now been applied to the larger X3 facility, and results for both facilities are presented.

  13. Simulation of Evacuated Tube Collector and Storage of Hybrid Air-conditioning System

    Directory of Open Access Journals (Sweden)

    Mustafa Ahmed Abdulhussain

    2018-02-01

    Full Text Available The CFD transient simulation of superheating the refrigerant R410 through the heat exchange with the evacuated tube water heating system of the hybrid split air conditioner that is subjected to solar radiation of constant intensity with the contribution of fan accelerated air is performed by the ANSYS-CFX code. The comparison with experimental work showed a minimum percentage error 8% of the predicted refrigerant evaporative heat transfer with storage tank horizontal tubing. In addition, the results denoted high absorption rate for the evacuated tubes, reducing highly reversed heat transmission for the circulated water. 

  14. Vertical steam generator with slab-type tube-plate with even tube bundle washing

    International Nuclear Information System (INIS)

    Manek, O.; Masek, V.; Motejl, V.; Quitta, R.

    1980-01-01

    A shielding plate supporting the tubes attached to the tube plate of a vertical steam generator is mounted above the tube plate. Tube sleeves are designed with a dimensional tolerance relative to the heat transfer tubes and the sleeve end and the tube plate end. A separate space is thus formed above the tube plate in which circulation or feed water is introduced to flow between the branch and the heat transfer tube. This provides intensive washing of heat transfer tubes at a critical point and prevents deposit formation, thus excluding heat transfer tube failures. (J.B.)

  15. Means and method for controlling the neutron output of a neutron generator tube

    International Nuclear Information System (INIS)

    1980-01-01

    A specification is given for an energizing and regulating circuit for a gas filled neutron generator tube consisting of a target, an ion source and a replenisher, the circuit consisting of a power supply to provide a negative high voltage to the target and a target current corresponding to the neutron output of the tube, a constant current source, and control means connected to the power supply and to the constant current source, the control means being responsive to the target current to provide a portion of the constant current to the replenisher substantially to regulate the neutron output of the tube. (author)

  16. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... Eye Disease Dilated Eye Exam Dry Eye For Kids Glaucoma Healthy Vision Tips Leber Congenital Amaurosis Low Vision Refractive Errors Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded ...

  17. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... and Aging Program African American Program Training and Jobs Fellowships NEI Summer Intern Program Diversity In Vision ... DIVRO) Student Training Programs To search for current job openings visit HHS USAJobs Home >> NEI YouTube Videos >> ...

  18. Technique for joining metal tubing

    Science.gov (United States)

    Wright, H. W.

    1976-01-01

    Uniform wall thickness and uninterrupted heat transfer is achieved by using shaped metal insert as wall material for joint. Insert acts as support during brazing, after which excess material is ground away to bring joint to original tubing size.

  19. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... questions Clinical Studies Publications Catalog Photos and Images Spanish Language Information Grants and Funding Extramural Research Division ... Low Vision Refractive Errors Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded video ...

  20. Cuffed endotracheal tubes in paediatrics

    African Journals Online (AJOL)

    cuffed endotracheal tubes (CETTs) in children who are younger than eight years old. Most paediatric ... the smallest functional part of the infant airway, because the ... During the 2003 severe acute respiratory syndrome (SARS) outbreak in ...

  1. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... Disease Education Program Glaucoma Education Program Low Vision Education Program Hispanic/Latino ... To search for current job openings visit HHS USAJobs Home » NEI YouTube ...

  2. Synthesis and characterization of a novel tube-in-tube nanostructured PPy/MnO2/CNTs composite for supercapacitor

    International Nuclear Information System (INIS)

    Li, Juan; Que, Tingli; Huang, Jianbin

    2013-01-01

    Graphical abstract: A novel tube-in-tube nanostructured PPy/MnO 2 /CNTs composite have been successfully fabricated. Its inner tubules are CNTs and the outer tubules are template-synthesized PPy. Most MnO 2 nanoparticles are sandwiched between the inner and outer wall, some relatively large particles are also latched onto the outside wall of the PPy tube. The composite yields a good electrochemical reversibility through 1000 cycles’ cyclic voltammogram (CV) test and galvanostatic charge–discharge experiments at different current densities. Display Omitted Highlights: ► We fabricate a ternary organic–inorganic complex of PPy/MnO 2 /CNTs composite. ► We characterize its morphological structures and properties by several techniques. ► The composite possesses the typical tube-in-tube nanostructures. ► Most MnO 2 nanoparticles are sandwiched between the inner CNTs and outer PPy wall. ► The composite has good electrochemical reversibility for supercapacitor. -- Abstract: Ternary organic–inorganic complex of polypyrrole/manganese dioxide/carbon nanotubes (PPy/MnO 2 /CNTs) composite was prepared by in situ chemical oxidation polymerization of pyrrole in the host of inorganic matrix of MnO 2 and CNTs, using complex of methyl orange (MO)/FeCl 3 was used as a reactive self-degraded soft-template. The morphological structures of the composite were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopic (HRTEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD), respectively. All the results indicate that the PPy/MnO 2 /CNTs composite possesses the typical tube-in-tube nanostructures: the inner tubules are CNTs and the outer tubules are template-synthesized PPy. MnO 2 nanoparticles may either sandwich the space between the inner and outer tubules or directly latch onto the wall of the PPy tubes. The composite yields a good electrochemical

  3. Monte Carlo modeling of neutron imaging at the SINQ spallation source

    International Nuclear Information System (INIS)

    Lebenhaft, J.R.; Lehmann, E.H.; Pitcher, E.J.; McKinney, G.W.

    2003-01-01

    Modeling of the Swiss Spallation Neutron Source (SINQ) has been used to demonstrate the neutron radiography capability of the newly released MPI-version of the MCNPX Monte Carlo code. A detailed MCNPX model was developed of SINQ and its associated neutron transmission radiography (NEUTRA) facility. Preliminary validation of the model was performed by comparing the calculated and measured neutron fluxes in the NEUTRA beam line, and a simulated radiography image was generated for a sample consisting of steel tubes containing different materials. This paper describes the SINQ facility, provides details of the MCNPX model, and presents preliminary results of the neutron imaging. (authors)

  4. Eddy current tube testing unit

    International Nuclear Information System (INIS)

    Dufayet, J.P.; Duret, G.

    1975-01-01

    The unit described can check a wide variety of tubes in quick succession and its modular design gives it a high degree of versability. Suitably defined working conditions and specific fittings enable most of the faults encountered in the manufacture of a tube to be detected. By appropriate means of selection based on signal amplitude, phase and frequency analyses it is possible to adapt selection criteria to the seriousness of the different categories of defect [fr

  5. The YouTube reader

    OpenAIRE

    2009-01-01

    YouTube has come to epitomize the possibilities of digital culture. With more than seventy million unique users a month and approximately eighty million videos online, this brand-name video distribution platform holds the richest repository of popular culture on the Internet. As the fastest growing site in the history of the Web, YouTube promises endless new opportunities for amateur video, political campaigning, entertainment formats, and viral marketing—a clip culture that has seemed to out...

  6. Gasification in a revolving tube

    International Nuclear Information System (INIS)

    Speicher, R.F.

    1981-01-01

    The concept of a method for allothermal coal gasification is to refine raw lignite from the Rhine area to high-quality synthesis gas or reduction gas without extracting the water utilizing nuclear process heat in a heated revolving bundle of tubes. Computational models are described for the macroscopic course of events in parallel flow gasification. In the design of the test plant, the principle of drag-in and transport of the tube drier was applied. (DG) [de

  7. Electronics for proportional drift tubes

    International Nuclear Information System (INIS)

    Fremont, G.; Friend, B.; Mess, K.H.; Schmidt-Parzefall, W.; Tarle, J.C.; Verweij, H.; CERN-Hamburg-Amsterdam-Rome-Moscow Collaboration); Geske, K.; Riege, H.; Schuett, J.; CERN-Hamburg-Amsterdam-Rome-Moscow Collaboration); Semenov, Y.; CERN-Hamburg-Amsterdam-Rome-Moscow Collaboration)

    1980-01-01

    An electronic system for the read-out of a large number of proportional drift tubes (16,000) has been designed. This system measures deposited charge and drift-time of the charge of a particle traversing a proportional drift tube. A second event can be accepted during the read-out of the system. Up to 40 typical events can be collected and buffered before a data transfer to a computer is necessary. (orig.)

  8. Transmission diamond imaging detector

    Energy Technology Data Exchange (ETDEWEB)

    Smedley, John, E-mail: smedley@bnl.gov; Pinelli, Don; Gaoweia, Mengjia [Brookhaven National Laboratory, Upton, NY (United States); Muller, Erik; Ding, Wenxiang; Zhou, Tianyi [Stony Brook University, Stony Brook, NY (United States); Bohon, Jen [Case Center for Synchrotron Biosciences, Center for Proteomics and Bioinformatics, Case Western Reserve University, Cleveland, OH (United States)

    2016-07-27

    Many modern synchrotron techniques are trending toward use of high flux beams and/or beams which require enhanced stability and precise understanding of beam position and intensity from the front end of the beamline all the way to the sample. For high flux beams, major challenges include heat load management in optics (including the vacuum windows) and a mechanism of real-time volumetric measurement of beam properties such as flux, position, and morphology. For beam stability in these environments, feedback from such measurements directly to control systems for optical elements or to sample positioning stages would be invaluable. To address these challenges, we are developing diamond-based instrumented vacuum windows with integrated volumetric x-ray intensity, beam profile and beam-position monitoring capabilities. A 50 µm thick single crystal diamond has been lithographically patterned to produce 60 µm pixels, creating a >1kilopixel free-standing transmission imaging detector. This device, coupled with a custom, FPGA-based readout, has been used to image both white and monochromatic x-ray beams and capture the last x-ray photons at the National Synchrotron Light Source (NSLS). This technology will form the basis for the instrumented end-station window of the x-ray footprinting beamline (XFP) at NSLS-II.

  9. Wireless data transmission from inside electromagnetic fields.

    Science.gov (United States)

    Huertas, José Ignacio; Barraza, Roberto; Echeverry, Julian Mauricio

    2010-01-01

    This paper describes analytical and experimental work developed to evaluate the effects of the electromagnetic fields produced by high-voltage lines (400 kV) on wireless data transmission at the 900MHz band. In this work the source of the data transmission is located inside the electromagnetic field and the reception station is located at different distances from the power lines. Different atmospheric conditions are considered.

  10. Tube-in-shell heat exchangers

    International Nuclear Information System (INIS)

    Richardson, J.

    1976-01-01

    Tube-in-shell heat exchangers normally comprise a bundle of parallel tubes within a shell container, with a fluid arranged to flow through the tubes in heat exchange with a second fluid flowing through the shell. The tubes are usually end supported by the tube plates that separate the two fluids, and in use the tube attachments to the tube plates and the tube plates can be subject to severe stress by thermal shock and frequent inspection and servicing are required. Where the heat exchangers are immersed in a coolant such as liquid Na such inspection is difficult. In the arrangement described a longitudinally extending central tube is provided incorporating axially spaced cylindrical tube plates to which the opposite ends of the tubes are attached. Within this tube there is a tubular baffle that slidably seals against the wall of the tube between the cylindrical tube plates to define two co-axial flow ducts. These ducts are interconnected at the closed end of the tube by the heat exchange tubes and the baffle comprises inner and outer spaced walls with the interspace containing Ar. The baffle is easily removable and can be withdrawn to enable insertion of equipment for inspecting the wall of the tube and tube attachments and to facilitate plugging of defective tubes. Cylindrical tube plates are believed to be superior for carrying pressure loads and resisting the effects of thermal shock. Some protection against thermal shock can be effected by arranging that the secondary heat exchange fluid is on the tube side, and by providing a thermal baffle to prevent direct impingement of hot primary fluid on to the cylindrical tube plates. The inner wall of the tubular baffle may have flexible expansible region. Some nuclear reactor constructions incorporating such an arrangement are described, including liquid metal reactors. (U.K.)

  11. Seismic source characterisation of a Tunnel Boring Machine (TBM)

    Science.gov (United States)

    Kreutzer, Ingrid; Brückl, Ewald; Radinger, Alexander

    2015-04-01

    The Tunnel Seismic While Drilling (TSWD) method aims at predicting continuously the geological situation ahead of the tunnel without disturbing the construction work. Thereby the Tunnel Boring Machine (TBM) itself is used as seismic source. The cutting process generates seismic waves radiating into the rock mass and vibrations propagating to the main bearing of the cutter head. These vibrations are monitored and used as pilot signal. For the processing and interpretation it was hypothesized so far that the TBM acts like a single force. To prove this assumption the radiation pattern of several TBM's under construction were investigated. Therefore 3-components geophones were installed at the surface, which were situated directly above the tunnel axes and also with lateral offset. Additional, borehole geophones were placed in the wall of one tube of a two-tube tunnel. The geophones collected the forward and backward radiated wave field, as the TBM, operating in the other tube, passed their positions. The obtained seismic data contains continuous records over a range of 600 m of the TBM position. The offsets vary from 25 m to 400 m and the frequency ranges from 20-250 Hertz. The polarisation of the p-wave and the s-wave and their amplitude ratio were determined and compared with modelled seismograms with different source mechanism. The results show that the description of the source mechanism by a single force can be used as a first order approximation. More complex radiation pattern including tensile forces and several source locations like the transmission of reaction forces over the gripper to the tunnel wall are further tested and addressed.

  12. Design of synchromesh mechanism to optimization manual transmission's electric vehicle

    Science.gov (United States)

    Zainuri, Fuad; Sumarsono, Danardono A.; Adhitya, Muhammad; Siregar, Rolan

    2017-03-01

    Significant research has been attempted on a vehicle that lead to the development of transmission that can reduce energy consumption and improve vehicle efficiency. Consumers also expect safety, convenience, and competitive prices. Automatic transmission (AT), continuously variable transmission (CVT), and dual clutch transmission (DCT) is the latest transmission developed for road vehicle. From literature reviews that have been done that this transmission is less effective on electric cars which use batteries as a power source compared to type manual transmission, this is due to the large power losses when making gear changes. Zeroshift system is the transmission can do shift gears with no time (zero time). It was developed for the automatic manual transmission, and this transmission has been used on racing vehicles to eliminate deceleration when gear shift. Zeroshift transmission still use the clutch to change gear in which electromechanical be used to replace the clutch pedal. Therefore, the transmission is too complex for the transmission of electric vehicles, but its mechanism is considered very suitable to increase the transmission efficiency. From this idea, a new innovation design transmission will be created to electric car. The combination synchromesh with zeroshift mechanism for the manual transmission is a transmission that is ideal for improving the transmission efficiency. Installation synchromesh on zeroshift mechanism is expected to replace the function of the clutch MT, and assisted with the motor torque setting when to change gear. Additionally to consider is the weight of the transmission, ease of manufacturing, ease of installation with an electric motor, as well as ease of use by drivers is a matter that must be done to obtain a new transmission system that is suitable for electric cars.

  13. Transmission Integration | Grid Modernization | NREL

    Science.gov (United States)

    Transmission Integration Transmission Integration The goal of NREL's transmission integration integration issues and provide data, analysis, and models to enable the electric power system to more and finding solutions to address them to enable transmission grid integration. Capabilities Power

  14. Steam generator tube integrity program: Phase II, Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, R.J.; Bickford, R.L.; Clark, R.A.; Morris, C.J.; Simonen, F.A.; Wheeler, K.R.

    1988-08-01

    The Steam Generator Tube Integrity Program (SGTIP) was a three phase program conducted for the US Nuclear Regulatory Commission (NRC) by Pacific Northwest Laboratory (PNL). The first phase involved burst and collapse testing of typical steam generator tubing with machined defects. The second phase of the SGTIP continued the integrity testing work of Phase I, but tube specimens were degraded by chemical means rather than machining methods. The third phase of the program used a removed-from-service steam generator as a test bed for investigating the reliability and effectiveness of in-service nondestructive eddy-current inspection methods and as a source of service degraded tubes for validating the Phase I and Phase II data on tube integrity. This report describes the results of Phase II of the SGTIP. The object of this effort included burst and collapse testing of chemically defected pressurized water reactor (PWR) steam generator tubing to validate empirical equations of remaining tube integrity developed during Phase I. Three types of defect geometries were investigated: stress corrosion cracking (SCC), uniform thinning and elliptical wastage. In addition, a review of the publicly available leak rate data for steam generator tubes with axial and circumferential SCC and a comparison with an analytical leak rate model is presented. Lastly, nondestructive eddy-current (EC) measurements to determine accuracy of defect depth sizing using conventional and alternate standards is described. To supplement the laboratory EC data and obtain an estimate of EC capability to detect and size SCC, a mini-round robin test utilizing several firms that routinely perform in-service inspections was conducted.

  15. Steam generator tube integrity program: Phase II, Final report

    International Nuclear Information System (INIS)

    Kurtz, R.J.; Bickford, R.L.; Clark, R.A.; Morris, C.J.; Simonen, F.A.; Wheeler, K.R.

    1988-08-01

    The Steam Generator Tube Integrity Program (SGTIP) was a three phase program conducted for the US Nuclear Regulatory Commission (NRC) by Pacific Northwest Laboratory (PNL). The first phase involved burst and collapse testing of typical steam generator tubing with machined defects. The second phase of the SGTIP continued the integrity testing work of Phase I, but tube specimens were degraded by chemical means rather than machining methods. The third phase of the program used a removed-from-service steam generator as a test bed for investigating the reliability and effectiveness of in-service nondestructive eddy-current inspection methods and as a source of service degraded tubes for validating the Phase I and Phase II data on tube integrity. This report describes the results of Phase II of the SGTIP. The object of this effort included burst and collapse testing of chemically defected pressurized water reactor (PWR) steam generator tubing to validate empirical equations of remaining tube integrity developed during Phase I. Three types of defect geometries were investigated: stress corrosion cracking (SCC), uniform thinning and elliptical wastage. In addition, a review of the publicly available leak rate data for steam generator tubes with axial and circumferential SCC and a comparison with an analytical leak rate model is presented. Lastly, nondestructive eddy-current (EC) measurements to determine accuracy of defect depth sizing using conventional and alternate standards is described. To supplement the laboratory EC data and obtain an estimate of EC capability to detect and size SCC, a mini-round robin test utilizing several firms that routinely perform in-service inspections was conducted

  16. Transmission X-ray mirror

    International Nuclear Information System (INIS)

    Lairson, B.M.; Bilderback, D.H.

    1982-01-01

    Transmission X-ray mirrors have been made from 400 A to 10 000 A thick soap films and have been shown to have novel properties. Using grazing angles of incidence, low energy X-rays were reflected from the front surface while more energetic X-rays were transmitted through the mirror largely unattenuated. A wide bandpass monochromator was made from a silicon carbide mirror followed by a soap film transmission mirror and operated in the white beam at the cornell High Energy Synchrotron Source (CHESS). Bandpasses of ΔE/E=12% to 18% were achieved at 13 keV with peak efficiencies estimated to be between 55% and 75%, respectively. Several wide angle scattering photographs of stretched polyethylene and a phospholipid were obtained in 10 s using an 18% bandpass. (orig.)

  17. Series Transmission Line Transformer

    Science.gov (United States)

    Buckles, Robert A.; Booth, Rex; Yen, Boris T.

    2004-06-29

    A series transmission line transformer is set forth which includes two or more of impedance matched sets of at least two transmissions lines such as shielded cables, connected in parallel at one end ans series at the other in a cascading fashion. The cables are wound about a magnetic core. The series transmission line transformer (STLT) which can provide for higher impedance ratios and bandwidths, which is scalable, and which is of simpler design and construction.

  18. A numerical study on the heat transfer in a swirl-tube heated/cooled on the half periphery of the tube wall

    International Nuclear Information System (INIS)

    Aoyama, Yoshiyuki; Kunugi, Tomoaki

    2002-01-01

    Convection heat transfer in a swirl tube was numerically analyzed so as to investigate a characteristic of heat removal when the cooling fluid flows within the swirl tube mounted in a solid structure represented as like a slab. Since the condition of heat inflow was treated as being transmitted only on the one-side surface of the structure, heat conduction through the structure was analyzed in linkage with the convection. Some results for the change in the coefficient of heat transmission along the tube axis are shown. The performance of heat removal was found to be strengthened due to the continuous renovation of thermal boundary layer close to the inside tube surface because the fluid flows in helical motion to shift the range alternate higher and lower temperature. (author)

  19. Application of radioisotope methods of investigation and control techniques in tube production

    International Nuclear Information System (INIS)

    Chizh, V.A.; Drabkin, L.A.

    1975-01-01

    Various spheres of radioactive isotopes application of closed and open type in tube production are described. Due to the usage of radioactive indicator method in combination with physicochemical methods and metallography new data are obtained in the theory and practice of tube centrifugal casting, rolling and pressing. Adsorption properties of lubricants and element distribution in the joint weld region of the big diameter tubes are investigated. The application of radioactive isotopes as ionizing radiation source made it possible to develop some radioisotope methods and instruments for tube wall thickness and the wall thickness difference control. Short characteristics of such instruments are given

  20. Drivers of Tuberculosis Transmission.

    Science.gov (United States)

    Mathema, Barun; Andrews, Jason R; Cohen, Ted; Borgdorff, Martien W; Behr, Marcel; Glynn, Judith R; Rustomjee, Roxana; Silk, Benjamin J; Wood, Robin

    2017-11-03

    Measuring tuberculosis transmission is exceedingly difficult, given the remarkable variability in the timing of clinical disease after Mycobacterium tuberculosis infection; incident disease can result from either a recent (ie, weeks to months) or a remote (ie, several years to decades) infection event. Although we cannot identify with certainty the timing and location of tuberculosis transmission for individuals, approaches for estimating the individual probability of recent transmission and for estimating the fraction of tuberculosis cases due to recent transmission in populations have been developed. Data used to estimate the probable burden of recent transmission include tuberculosis case notifications in young children and trends in tuberculin skin test and interferon γ-release assays. More recently, M. tuberculosis whole-genome sequencing has been used to estimate population levels of recent transmission, identify the distribution of specific strains within communities, and decipher chains of transmission among culture-positive tuberculosis cases. The factors that drive the transmission of tuberculosis in communities depend on the burden of prevalent tuberculosis; the ways in which individuals live, work, and interact (eg, congregate settings); and the capacity of healthcare and public health systems to identify and effectively treat individuals with infectious forms of tuberculosis. Here we provide an overview of these factors, describe tools for measurement of ongoing transmission, and highlight knowledge gaps that must be addressed. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

  1. Development of Yb-169 radiation source for new nondestructive inspection

    International Nuclear Information System (INIS)

    Yamabayashi, Hisamichi

    1994-01-01

    As the nondestructive inspection method for large structures, there has been radiography, and X-ray and γ-ray have been used as the radiation. The transmissivity of radiation through materials changes by the energy of the radiation and the density and thickness of the materials. At present about 880 γ-ray radiography apparatuses are used in Japanese private enterprises, and about 70% of them use 192 Ir γ-ray sources, and about 30% use 60 Co or 137 Cs sources. Recently the defect inspection for the worlded parts of thin wall small tubes and so on have become to be regarded as important, and the 169 Yb source that emits lower energy γ-ray is suitable to the purpose. There are many reports that 169 Yb radiography was applied successfully. As the 169 Yb radiation source, pellets and balls are on the market. 169 Yb is made by the neutron irradiation of 168 Yb in nuclear reactors. The characteristics of 169 Yb, the manufacture of 169 Yb radiation sources and the applicability of 169 Yb radiation sources to nondestructive inspection are reported. Also in Japan, many basic experiments on 169 Yb radiation sources have been carried out, and the irradiation apparatuses are small and light, and the control area can be set small. (K.I.)

  2. Tubing vs. buckets: a cost comparison

    Science.gov (United States)

    Neil K. Huyler

    1975-01-01

    Equipment investment for tubing-vacuum systems was significantly less than that for bucket systems. Tubing-vacuum systems required about 22 percent less labor input, the major labor input being completed before sap-flow periods. Annual cost of operation was less for tubing-vacuum than the bucket system. Small tubing-vacuum operations showed more profit potential than...

  3. Expander for Thin-Wall Tubing

    Science.gov (United States)

    Pessin, R.

    1983-01-01

    Tool locally expands small-diameter tubes. Tube expander locally expands and deforms tube: Compressive lateral stress induced in elastomeric sleeve by squeezing axially between two metal tool parts. Adaptable to situations in which tube must have small bulge for mechanical support or flow control.

  4. The interior transmission spectrum in one dimension

    International Nuclear Information System (INIS)

    Hickmann, Kyle S

    2012-01-01

    This paper seeks conditions on acoustic profiles c(x) and b(x) which imply the existence of intervals free of transmission eigenvalues. The existence of intervals free of transmission eigenvalues has important implications in the question of unique recovery of the acoustic profile for inverse acoustic scattering theory using the linear sampling method and for the inverse source problem in thermoacoustic tomography. We examine the interior transmission spectrum relative to two acoustic profiles on the unit interval. This research includes the case when the difference of the two acoustic profiles changes sign and is, to the author's knowledge, the only work to date on the interior transmission spectrum allowing this behavior. It is shown that for a large class of acoustic profiles the transmission spectrum is asymptotically sparse. The spectrum exhibits three distinct types of behavior dependent on the relation of the two acoustic profiles. Numerical examples of each type of behavior are given which show how the transmission eigenvalues are distributed depending on the relation between c(x) and b(x). Our method of study is to reduce the interior transmission problem on [0, 1] to a problem of finding roots of a determinant of fundamental solutions to a Sturm–Liouville problem. The asymptotic expansion of solutions of the Sturm–Liouville problem then allows us to analyze properties of the transmission spectrum for large values of the wavenumber. (paper)

  5. Free Piston Double Diaphragm Shock Tube

    OpenAIRE

    OGURA, Eiji; FUNABIKI, Katsushi; SATO, Shunichi; ABE, Takashi; 小倉, 栄二; 船曳, 勝之; 佐藤, 俊逸; 安部, 隆士

    1997-01-01

    A free piston double diaphragm shock tube was newly developed for generation of high Mach number shock wave. Its characteristics was investigated for various operation parameters; such as a strength of the diaphragm at the end of the comparession tube, an initial pressure of low pressure tube, an initial pressure of medium pressure tube and the volume of compression tube. Under the restriction of fixed pressures for the driver high pressure tube (32×10^5Pa) and the low pressure tube (40Pa) in...

  6. PWR steam generator tubing sample library

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    In order to compile the tubing sample library, two approaches were employed: (a) tubing sample replication by either chemical or mechanical means, based on field tube data and metallography reports for tubes already destructively examined; and (b) acquisition of field tubes removed from operating or retired steam generators. In addition, a unique mercury modeling concept is in use to guide the selection of replica samples. A compendium was compiled that summarizes field observations and morphologies of steam generator tube degradation types based on available NDE, destructive examinations, and field reports. This compendium was used in selecting candidate degradation types that were manufactured for inclusion in the tube library

  7. Pump element for a tube pump

    DEFF Research Database (Denmark)

    2011-01-01

    The invention relates to a tube pump comprising a tube and a pump element inserted in the tube, where the pump element comprises a rod element and a first and a second non-return valve member positioned a distance apart on the rod element. The valve members are oriented in the same direction...... relative to the rod element so as to allow for a fluid flow in the tube through the first valve member, along the rod element, and through the second valve member. The tube comprises an at least partly flexible tube portion between the valve members such that a repeated deformation of the flexible tube...... portion acts to alternately close and open the valve members thereby generating a fluid flow through the tube. The invention further relates to a pump element comprising at least two non-return valve members connected by a rod element, and for insertion in an at least partly flexible tube in such tube...

  8. Managing a chest tube and drainage system.

    Science.gov (United States)

    Durai, Rajaraman; Hoque, Happy; Davies, Tony W

    2010-02-01

    Intercostal drainage tubes (ie, chest tubes) are inserted to drain the pleural cavity of air, blood, pus, or lymph. The water-seal container connected to the chest tube allows one-way movement of air and liquid from the pleural cavity. The container should not be changed unless it is full, and the chest tube should not be clamped unnecessarily. After a chest tube is inserted, a nurse trained in chest-tube management is responsible for managing the chest tube and drainage system. This entails monitoring the chest-tube position, controlling fluid evacuation, identifying when to change or empty the containers, and caring for the tube and drainage system during patient transport. This article provides an overview of indications, insertion techniques, and management of chest tubes. Copyright 2010 AORN, Inc. Published by Elsevier Inc. All rights reserved.

  9. Characterization of Zircaloy-4 tubing procured for fuel cladding research programs

    International Nuclear Information System (INIS)

    Chapman, R.H.

    1976-01-01

    A quantity of Zircaloy-4 tubing [10.92 mm outside diameter by 0.635 mm wall thickness] was purchased specifically for use in a number of related fuel cladding research programs sponsored by the Division of Reactor Safety Research, Nuclear Regulatory Commission (NRC/RSR). Identical tubing (produced simultaneously and from the same ingot) was purchased concurrently by the Electric Power Research Institute (EPRI) for use in similar research programs sponsored by that organization. In this way, source variability and prior fabrication history were eliminated as parameters, thus permitting direct comparison (as far as as-received material properties are concerned) of experimental results from the different programs. The tubing is representative of current reactor technology. Consecutive serial numbers assigned to each tube identify the sequence of the individual tubes through the final tube wall reduction operation. The report presented documents the procurement activities, provides a convenient reference source of manufacturer's data and tubing distribution to the various users, and presents some preliminary characterization data. The latter have been obtained routinely in various research programs and are not complete. Although the number of analyses, tests, and/or examinations performed to date are insufficient to draw statistically valid conclusions with regard to material characterization, the data are expected to be representative of the as-received tubing. It is anticipated that additional characterizations will be performed and reported routinely by the various research programs that use the tubing

  10. Application of transmission scan-based attenuation compensation to scatter-corrected thallium-201 myocardial single-photon emission tomographic images

    International Nuclear Information System (INIS)

    Hashimoto, Jun; Kubo, Atsushi; Ogawa, Koichi; Ichihara, Takashi; Motomura, Nobutoku; Takayama, Takuzo; Iwanaga, Shiro; Mitamura, Hideo; Ogawa, Satoshi

    1998-01-01

    A practical method for scatter and attenuation compensation was employed in thallium-201 myocardial single-photon emission tomography (SPET or ECT) with the triple-energy-window (TEW) technique and an iterative attenuation correction method by using a measured attenuation map. The map was reconstructed from technetium-99m transmission CT (TCT) data. A dual-headed SPET gamma camera system equipped with parallel-hole collimators was used for ECT/TCT data acquisition and a new type of external source named ''sheet line source'' was designed for TCT data acquisition. This sheet line source was composed of a narrow long fluoroplastic tube embedded in a rectangular acrylic board. After injection of 99m Tc solution into the tube by an automatic injector, the board was attached in front of the collimator surface of one of the two detectors. After acquiring emission and transmission data separately or simultaneously, we eliminated scattered photons in the transmission and emission data with the TEW method, and reconstructed both images. Then, the effect of attenuation in the scatter-corrected ECT images was compensated with Chang's iterative method by using measured attenuation maps. Our method was validated by several phantom studies and clinical cardiac studies. The method offered improved homogeneity in distribution of myocardial activity and accurate measurements of myocardial tracer uptake. We conclude that the above correction method is feasible because a new type of 99m Tc external source may not produce truncation in TCT images and is cost-effective and easy to prepare in clinical situations. (orig.)

  11. Analysis of forming limit in tube hydroforming

    International Nuclear Information System (INIS)

    Kim, Chan Il; Yang, Seung Hang; Kim, Young Suk

    2013-01-01

    The automotive industry has shown increasing interest in tube hydroforming. Despite many automobile structural parts being produced from cylindrical tubes, failures frequently occur during tube hydroforming under improper forming conditions. These problems include wrinkling, buckling, folding back, and bursting. We perform analytical studies to determine forming limits in tube hydroforming and demonstrate how these forming limits are influenced by the loading path. Theoretical results for the forming limits of wrinkling and bursting are compared with experimental results for an aluminum tube.

  12. Top of tubesheet cracking in Bruce A NGS steam generator tubing - recent experience

    International Nuclear Information System (INIS)

    Clark, M.A.; Lepik, O.; Mirzai, M.; Thompson, I.

    1998-01-01

    During the Bruce A Nuclear Generating Station (BNGS-A) Unit 1 1997 planned outage, a dew point search method identified a leak in one steam generator(SG) tube. Subsequently, the tube was inspected with all available eddy current probes and removed for examination. The initial inspection results and metallurgical examination of the removed tube confirmed that the leak was due to intergranular attack/stress corrosion cracking (IGA/SCC) emanating from the secondary side of the tube at the top of the tubesheet location. Subsequently, eddy current and ultrasonic indications were found at the top of the tubesheet of other Alloy 600 SG tubes. To investigate the source of the indications and to validate the inspection probes, sections of 40 tubes with various levels of damage were removed. The metallurgical examination of the removed sections showed that both secondary side and primary side initiated, circumferential, stress corrosion cracking and intergranular attack occurred in the BNGS-A SG tubing. Significant degradation from both mechanisms was found, invariably located in the roll transition region of the top expansion joint between the tube and the tubesheet on the hot leg (304 degrees C) side of the tube. Various aspects of the failures and tube examinations are presented in this paper, including presentation of the cracking morphology, measured crack size distributions, and discussion of some factors possibly affecting the cracking. (author)

  13. Actively-stabilized photomultiplier tube base for vacuum operation

    International Nuclear Information System (INIS)

    Bryan, M.A; Morris, C.L.; Idzorek, G.C.

    1992-01-01

    An actively stabilized photomultiplier tube (PMT) base design for an Amperex XP-2262B PMT is described. Positive-negative-positive transistors are used as low-impedance current sources to maintain constant voltages on the last three dynodes. This technique results in a highly stable, low-power tube base ideal for use with low-duty-factor beams, such as those found at the Clinton P. Anderson Meson Physics Facility. Furthermore, because of the low power usage of this large design, these bases can be sealed in a heat-conductive, electrically insulating material and used in a vacuum

  14. Analysis of autofrettaged metal tubes

    International Nuclear Information System (INIS)

    Malik, M. Afzaal; Khan, Muddasar; Rashid, Badar; Khushnood, Shahab

    2007-01-01

    Thick-walled cylinders are widely used as compressor cylinders, pump cylinders, high pressure tubing, process reactors and vessels, nuclear reactors, isostatic vessels and gun barrels. In practice, cylinders are generally subjected to sudden and frequently drastic pressure fluctuations, such as the pressure generated in a gun barrel upon the firing of the weapon, pressure reversals in pump cylinders or in process reactors employing high-pressure piping, necessitating enhanced strength of such cylinders. A process for enhancing the strength of thick-walled cylinders has been in service, and is referred to as 'autofrettage'. It extends the service life of the cylinder. The autofrettage is achieved by increasing elastic strength of a cylinder with various methods such as hydraulic pressurization, mechanical swaging, or by utilizing the pressure of a powder gas. This research work deals with the hydraulic and mechanical autofrettage of metal tubes with the objective to attain enhanced strength. Five metal tubes are taken randomly for analysis purpose. The experimental data for five metal tubes is obtained to analyze the behavior of different parameters used during, before, and after autofrettage process. For this research, two-stage autofrettage is taken into consideration. The modeling of the metal tube is carried out in WildFire-ProEngineering, and for analysis purpose, finite element software ANSYS7 and COSMOS are used. The graphical analysis of swage autofrettage is carried out using MATLAB7. The results are validated using available experimental and numerical data. (author)

  15. Physics of magnetic flux tubes

    CERN Document Server

    Ryutova, Margarita

    2015-01-01

    This book is the first account of the physics of magnetic flux tubes from their fundamental properties to collective phenomena in an ensembles of flux tubes. The physics of magnetic flux tubes is absolutely vital for understanding fundamental physical processes in the solar atmosphere shaped and governed by magnetic fields. High-resolution and high cadence observations from recent space and  ground-based instruments taken simultaneously at different heights and temperatures not only show the ubiquity of filamentary structure formation but also allow to study how various events are interconnected by system of magnetic flux tubes. The book covers both theory and observations. Theoretical models presented in analytical and phenomenological forms are tailored for practical applications. These are welded with state-of-the-art observations from early decisive ones to the most recent data that open a new phase-space for exploring the Sun and sun-like stars. Concept of magnetic flux tubes is central to various magn...

  16. Cultural Transmission of Civicness

    DEFF Research Database (Denmark)

    Ljunge, Jan Martin

    2012-01-01

    This paper estimates the intergeneration transmission of civicness by studying second generation immigrants in 29 European countries with ancestry in 83 nations. There is significant transmission of civicness both on the mother’s and the father’s side. The estimates are quantitatively significant...

  17. Cultural Transmission of Civicness

    DEFF Research Database (Denmark)

    Ljunge, Jan Martin

    This paper estimates the intergeneration transmission of civicness by studying second generation immigrants in 29 European countries with ancestry in 83 nations. There is significant transmission of civicness both on the mother’s and the father’s side. The estimates are quantitatively significant...

  18. Poverty and price transmission

    DEFF Research Database (Denmark)

    Elleby, Christian

    A key parameter determining the welfare impact from a world market shock is the transmission elasticity which measures the average domestic response to an international price change. Many studies have estimated price transmission elasticities for a large number of countries but the variation in t...

  19. Transmission market support system

    International Nuclear Information System (INIS)

    Reinschmidt, K.F.; Coles, B.C.

    1995-01-01

    An interactive, computer-based market support system has been developed for transmission access that is efficient, equitable, and fair to all parties concerned with electrical transmission: utilities, electric generators, owners of transmission networks, and wholesale purchasers of electrical power. Each participant transmits electronically to the computer system his proposed price schedule for buying, selling, or transmitting power for each future time period. The price for transmission on a single line in one direction can differ from the price in the other direction. The total quantity offered in the transmission bid represents the capacity of the line, and the flow on the line cannot exceed this value. The system automatically computes the prices that clear the market; that is, the price that each generator receives at each bus, the price that each transmission operator receives on each line, and the price that each customer pays at each bus. The computer system maximizes the benefits to all three classes while satisfying the electrical characteristics of the transmission system by means of load flow calculations. Customers never pay more than their bid prices (but may pay less), and generators and transmission operators never receive less than their bid prices (but may receive more). The price at each bus applies to all buyers and sellers at that bus: all buyers at the same bus pay the same price and all generators at a bus receive the same price

  20. Pricing transmission services

    International Nuclear Information System (INIS)

    Haaden, E.

    1995-01-01

    The price structure for transmission of electric power through the main lines in Sweden is analyzed. After deregulation of the electricity market, the main transmission lines are owned by a separate national company, with no interests from the power producers. Comparisons are made to ideal marginal price structures. 6 refs

  1. Eliminating Perinatal HIV Transmission

    Centers for Disease Control (CDC) Podcasts

    In this podcast, CDC’s Dr. Steve Nesheim discusses perinatal HIV transmission, including the importance of preventing HIV among women, preconception care, and timely HIV testing of the mother. Dr. Nesheim also introduces the revised curriculum Eliminating Perinatal HIV Transmission intended for faculty of OB/GYN and pediatric residents and nurse midwifery students.

  2. Electric transmission technology

    International Nuclear Information System (INIS)

    Shah, K.R.

    1990-01-01

    Electric transmission technology has matured and can transmit bulk power more reliably and economically than the technology 10 years ago.In 1882, Marcel Depres transmitted 15 kW electric power at 2 kV, using a constant direct current; present transmission voltages have risen to ± 600 kV direct current (DC) and 765 kV alternating current (AC), and it is now possible to transmit bulk electric power at voltages as high as ± 1000 kV DC and 1500 kV AC. Affordable computer systems are now available to optimize transmission reliably. New materials have reduced the bulk of insulation for lines and equipment. New conducting materials and configurations have reduced losses in transmission. Advances in line structures and conductor motion, understanding of flashover characteristics of insulators and air-gaps and electrical performance of lines have resulted in more compact urban transmission lines. (author). 15 refs., 7 tabs., 11 figs

  3. Microwave energy transmission

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Hiroshi [Kyoto Univ. (Japan)

    1989-03-05

    Laying stress on the technological problems and effect on the environment of microwave energy transmission, recent scientific and engineering problems and related subjects are described. Because no fuel is required for the solar power generation, the power generation system can not be considered as an expensive one when the unit cost of energy is taken into consideration. Some of the important technological problems in the microwave energy transmission are accurate microwave beam control technology to receiving stations and improvement in the efficiency of transmission system. Microwave energy beam has effects on living bodies, communication, and plasma atmosphere of the earth. Microwave energy transmission using a space flyer unit is scheduled. Its objective is the development of microwave wireless transmission technology and the study of the correlation between high power microwave and ionosphere plasma. Experiments on such a small scale application as a microwave driven space ship to bring results seem also important. 12 refs., 13 figs.

  4. Photodynamic therapy to destroy pneumonia associated microorganisms using external irradiation source

    Science.gov (United States)

    Bassi, Rosane; Myakawa, Walter; Navarro, Ricardo S.; Baptista, Alessandra; Ribeiro, Martha Simões; Nunez, Silvia Cristina

    2018-02-01

    An endotracheal tube (ETT) is required for the management of critically ill, mechanically ventilated patients. Ventilatorassociated pneumonia (VAP) affects patients hospitalized in intensive care units; its risk of occurrence is 1% to up 3% for each day of mechanical ventilation. The polymicrobial nature of VAP is established with mixed bacterial-fungal biofilms colonizing the ETT. The microbial interaction enhances the microbial pathogenesis contributing to high indexes of morbidity/mortality. Antimicrobial Photodynamic Therapy (aPDT) could be a suitable therapy for decontamination of oral cavity and ETT at the same time, but the use of a fiber optics inside the ETT seems to not be appropriated since a cannula for secretion aspiration has to be introduced into the ETT to keep it's lumen. The aim of this study is to proof the concept that an external light source from a LED is capable of reach all areas of the ETT. We use a commercial ETT, 60μM methylene blue (MB), and a 660nm diode laser and calculated the transmission coefficient of light in different situations as only tube, tube with biofilm and biofilm+MB. The results prove that is possible to transmit light through the tube even in the presence of MB and biofilm although a high attenuation of about 60% was measured depending on the tested condition.

  5. Drift tubes of Linac 2

    CERN Multimedia

    CERN PhotoLab

    1977-01-01

    With the advent of the 800 MeV PS Booster in 1972, the original injector of the PS, a 50 MeV Alvarez-type proton linac, had reached its limits, in terms of intensity and stability. In 1973 one therefore decided to build a new linac (Linac 2), also with a drift-tube Alvarez structure and an energy of 50 MeV. It had a new Cockcroft-Walton preinjector with 750 keV, instead of the previous one with 500 keV. Linac 2 was put into service in 1980. The old Linac 1 was then used for the study of, and later operation with, various types of ions. This picture shows Linac 2 drift-tubes, suspended on stems coming from the top, in contrast to Linac 1, where the drift-tubes stood on stems coming from the bottom.

  6. On hydraulics of capillary tubes

    Directory of Open Access Journals (Sweden)

    N.G. Aloyan

    2016-03-01

    Full Text Available The article considers the laws of motion of water in the capillary tubes, taken as a model for flowing well, on the analogical net count device. For capillary tube the lower limit value of flow rate is empirically determined above which the total hydraulic resistance of the capillary is practically constant. The specificity of the phenomenon is that the regime of motion, by a Reynolds number, for a given flow rate still remains laminar. This circumstance can perplex the specialists, so the author invites them to the scientific debate on the subject of study. Obviously, to identify the resulting puzzle it is necessary to conduct a series of experiments using capillaries of different lengths and diameters and with different values of overpressure. The article states that in tubes with very small diameter the preliminary magnitude of capillary rise of water in the presence of flow plays no role and can be neglected.

  7. Tubing and cable cutting tool

    Science.gov (United States)

    Mcsmith, D. D.; Richardson, J. I. (Inventor)

    1984-01-01

    A hand held hydraulic cutting tool was developed which is particularly useful in deactivating ejection seats in military aircraft rescue operations. The tool consists primarily of a hydraulic system composed of a fluid reservoir, a pumping piston, and an actuator piston. Mechanical cutting jaws are attached to the actuator piston rod. The hydraulic system is controlled by a pump handle. As the pump handle is operated the actuator piston rod is forced outward and thus the cutting jaws are forced together. The frame of the device is a flexible metal tubing which permits easy positioning of the tool cutting jaws in remote and normally inaccessible locations. Bifurcated cutting edges ensure removal of a section of the tubing or cable to thereby reduce the possibility of accidental reactivation of the tubing or cable being severed.

  8. Time-Domain Analysis of Coupled Carbon Nano tube Interconnects

    International Nuclear Information System (INIS)

    Fathi, D.

    2014-01-01

    This paper describes a new method for the analysis of coupling effects including the crosstalk effects between two driven coupled single-walled carbon nano tubes (SWCNTs) and the intertalk effects between two neighboring shells in a multi walled carbon nano tube (MWCNT), based on transmission line circuit modeling. Using rigorous calculations, a new parametric transfer function has been obtained for the analysis of the impact of aggressor line on the victim line, which depends on the various coupling parameters such as the mutual inductance, the coupling capacitance, and the tunneling resistance. The influences of various parameters such as the contact resistance and the switching factor on the time behavior of coupling effects between the two coupled CNTs and an important effect named “crosstalk-induced delay” are studied and analyzed

  9. Synthesis of Boron Nano wires, Nano tubes, and Nano sheets

    International Nuclear Information System (INIS)

    Patel, R.B.; Chou, T.; Iqbal, Z.

    2014-01-01

    The synthesis of boron nano wires, nano tubes, and nano sheets using a thermal vapor deposition process is reported. This work confirms previous research and provides a new method capable of synthesizing boron nano materials. The materials were made by using various combinations of MgB 2 , Mg(BH 4 ) 2 , MCM-41, NiB, and Fe wire. Unlike previously reported methods, a nanoparticle catalyst and a silicate substrate are not required for synthesis. Two types of boron nano wires, boron nano tubes, and boron nano sheets were made. Their morphology and chemical composition were determined through the use of scanning electron microscopy, transmission electron microscopy, and electron energy loss spectroscopy. These boron-based materials have potential for electronic and hydrogen storage applications.

  10. Optical effects on neutron guide tubes produced by collimation

    International Nuclear Information System (INIS)

    Margaca, F.M.A.; Falcao, A.N.; Sequeira, A.D.; Salgado, J.F.

    1991-01-01

    The collimation of a neutron beam carried by a guide tube is shown to procedure extensive regions of umbra and penumbra on the inner walls of the guide tube whenever a diaphragm is used at the exit. The region of umbra renders useless a certain length of the guide-tube end while in the region of penumbra the guide exhibits a faint luminosity. These optical effects are particularly important for stringent collimation. It is shown that these effects render impossible the implementation of the 'equal-flight-paths' design currently used for small-angle neutron scattering instruments, which use guide segments and a diaphragm in the collimation assembly. As a consequence, these operate most of the time in strongly unmatched configurations. It is shown that the optimized design formerly proposed by the authors, in which, whenever possible, the full luminous source area is used, not only avoids the optical effects mentioned but also guarantees the highest detector count rate. (orig.)

  11. Re-examination of demonstration gas discharge tubes

    International Nuclear Information System (INIS)

    Maharaj, H.P.

    1991-01-01

    Gas discharge tubes in which electrons or ions are accelerated at voltages on the order of kilovolts to produce observable atomic effects are potential x-ray sources. These tubes come in various shapes, sizes and designs, and are still in use in science classrooms despite the decline predicted in the 1970s. Because of current applications, a representative sample consisting of fifteen tubes marketed over a recent 2-year period was reexamined for regulatory compliance, product identification and advertising. The results revealed that: poor quality control and design can affect x-ray emissions; and deficiencies exist in product identification, safe use guidelines and operating instructions. This paper reports that these findings, together with the dose estimates, implications and subjective indicators, strongly suggest a user group of unknown size is at increased risk. A combination of enhanced surveillance and promotion of user awareness strategies is adopted to reduce and possible eliminate the potential health risks

  12. Low Power Measurements on a Finger Drift Tube Linac

    CERN Document Server

    Schempp, A

    2004-01-01

    The efficiency of RFQs decreases at higher particle energies. The DTL structures used in this energy regions have a defocusing influence on the beam. To achieve a focusing effect, fingers with quadrupole symmetry were added to the drift tubes. Driven by the same power supply as the drift tubes, the fingers do not need an additional power source or feedthrough. Beam dynamics have been studied with PARMTEQ . Detailed analysis of the field distribution was done and the geometry of the finger array has been optimized with respect to beam dynamics. A spiral loaded cavity with finger drift tubes was built up and low power measurements were done. In this contribution, the results of the rf simulating with Microwave Studio are shown in comparison with bead pertubation measurement on a prototype cavity.

  13. Thoracostomy tubes: A comprehensive review of complications and related topics

    Science.gov (United States)

    Kwiatt, Michael; Tarbox, Abigail; Seamon, Mark J.; Swaroop, Mamta; Cipolla, James; Allen, Charles; Hallenbeck, Stacinoel; Davido, H. Tracy; Lindsey, David E.; Doraiswamy, Vijay A.; Galwankar, Sagar; Tulman, David; Latchana, Nicholas; Papadimos, Thomas J.; Cook, Charles H.; Stawicki, Stanislaw P.

    2014-01-01

    Tube thoracostomy (TT) placement belongs among the most commonly performed procedures. Despite many benefits of TT drainage, potential for significant morbidity and mortality exists. Abdominal or thoracic injury, fistula formation and vascular trauma are among the most serious, but more common complications such as recurrent pneumothorax, insertion site infection and nonfunctioning or malpositioned TT also represent a significant source of morbidity and treatment cost. Awareness of potential complications and familiarity with associated preventive, diagnostic and treatment strategies are fundamental to satisfactory patient outcomes. This review focuses on chest tube complications and related topics, with emphasis on prevention and problem-oriented approaches to diagnosis and treatment. The authors hope that this manuscript will serve as a valuable foundation for those who wish to become adept at the management of chest tubes. PMID:25024942

  14. Biocompatibility of Different Nerve Tubes

    Science.gov (United States)

    Stang, Felix; Keilhoff, Gerburg; Fansa, Hisham

    2009-01-01

    Bridging nerve gaps with suitable grafts is a major clinical problem. The autologous nerve graft is considered to be the gold standard, providing the best functional results; however, donor site morbidity is still a major disadvantage. Various attempts have been made to overcome the problems of autologous nerve grafts with artificial nerve tubes, which are “ready-to-use” in almost every situation. A wide range of materials have been used in animal models but only few have been applied to date clinically, where biocompatibility is an inevitable prerequisite. This review gives an idea about artificial nerve tubes with special focus on their biocompatibility in animals and humans.

  15. Working session 3: Tubing integrity

    International Nuclear Information System (INIS)

    Cueto-Felgueroso, C.; Strosnider, J.

    1997-01-01

    Twenty-three individuals representing nine countries (Belgium, Canada, the Czech Republic, France, Japan, the Slovak Republic, Spain, the UK, and the US) participated in the session on tube integrity. These individuals represented utilities, vendors, consultants and regulatory authorities. The major subjects discussed by the group included overall objectives of managing steam generator tube degradation, necessary elements of a steam generator degradation management program, the concept of degradation specific management, structural integrity evaluations, leakage evaluations, and specific degradation mechanisms. The group's discussions on these subjects, including conclusions and recommendations, are summarized in this article

  16. The Sealed Tube Neutron Generator

    International Nuclear Information System (INIS)

    Tunnell, L.N.; Beyerle, A.; Durkee, R.; Headley, G.; Hurley, P.

    1992-01-01

    A Sealed Tube Neutron Generator (STNG) has been designed and tested at Special Technologies Laboratories (STL) in Santa Barbara, California. Unlike similar tubes that have been used for years in other applications, e.g., by the oil well logging industry, the present device was designed primarily to be part of the Associated Particle Imaging (API) system. Consequently, the size and quality of the neutron spot produced by the STNG is of primary importance. Results from initial measurements indicate that performance goals are satisfied

  17. YouTube and Facebook

    DEFF Research Database (Denmark)

    Robertson, Scott P.; Vatrapu, Ravi; Medina, Richard

    This paper examines the links to YouTube from the Facebook “walls” of Barack Obama, Hillary Clinton, and John McCain over two years prior to the 2008 U.S. Presidential election. User-generated linkage patterns show how participants in these politically-related social networking dialogues used...... online video to make their points. We show a strong integration of the Web 2.0 and new media technologies of social networking and online video. We argue that political discussion in social networking environments can no longer be viewed as primarily textual, and that neither Facebook nor YouTube can...

  18. Core barrel inner tube lifter

    Energy Technology Data Exchange (ETDEWEB)

    Jeffers, J P

    1968-07-16

    A core drill with means for selectively lifting a core barrel inner tube consists of a lifting means connected to the core barrel inner tube assembly. It has a closable passage to permit drilling fluid normally to pass through it. The lifting means has a normally downward facing surface and a means to direct drilling fluid pressure against that surface so that on closure of the passage to fluid flow, the pressure of the drilling fluid is caused to act selectively on it. This causes the lifting means to rise and lift the core barrel. (7 claims)

  19. Opposed slant tube diabatic sorber

    Science.gov (United States)

    Erickson, Donald C.

    2004-01-20

    A sorber comprised of at least three concentric coils of tubing contained in a shell with a flow path for liquid sorbent in one direction, a flow path for heat transfer fluid which is in counter-current heat exchange relationship with sorbent flow, a sorbate vapor port in communication with at least one of sorbent inlet or exit ports, wherein each coil is coiled in opposite direction to those coils adjoining it, whereby the opposed slant tube configuration is achieved, with structure for flow modification in the core space inside the innermost coil.

  20. The FINUDA straw tube detector

    CERN Document Server

    Zia, A; Bertani, M; Bianco, S; Fabbri, Franco Luigi; Gianotti, P; Giardoni, M; Lucherini, V; Mecozzi, A; Pace, E; Passamonti, L; Qaiser, N; Russo, V; Tomassini, S; Sarwar, S; Serdyouk, V

    2001-01-01

    An array of 2424 2.6- m-long, 15- mm-diameter mylar straw tubes, arranged in two axial and four stereo layers, has been assembled at National Laboratories of Frascati of INFN for the FINUDA experiment. The array covers a cylindrical tracking surface of 18 m sup 2 and provides coordinate measurement in the drift direction and along the wire with a resolution of the order of 100 and 300 mu m, respectively. The array has finished the commissioning phase and tests with cosmic rays are underway. The status straw tubes array and a very preliminary result from cosmic rays test are summarized in this work.