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Sample records for automatic tube current

  1. Automatic Inspection of Nuclear-Reactor Tubes During Production and Processing, Using Eddy-Current Methods

    International Nuclear Information System (INIS)

    The possibilities of automatic and semi-automatic inspection of tubes using eddy-current methods are described. The paper deals in particular with modem processes, compared to the use of other non-destructive methods. The essence of the paper is that the methods discussed are ideal for objective automatic inspection. Not only are the known methods described, but certain new methods and their application to the detection of flaws in reactor tubes are discussed. (author)

  2. Extraction: a system for automatic eddy current diagnosis of steam generator tubes in nuclear power plants

    International Nuclear Information System (INIS)

    Improving speed and quality of Eddy Current non-destructive testing of steam generator tubes leads to automatize all processes that contribute to diagnosis. This paper describes how we use signal processing, pattern recognition and artificial intelligence to build a software package that is able to automatically provide an efficient diagnosis. (authors). 2 figs., 5 refs

  3. Relationships between patient size, dose and image noise under automatic tube current modulation systems

    International Nuclear Information System (INIS)

    Automatic tube current modulation (ATCM) systems are now used for the majority of CT scans. The principles of ATCM operation are different in CT scanners from different manufacturers. Toshiba and GE scanners base the current modulation on a target noise setting, while Philips and Siemens scanners use reference image and reference mAs concepts respectively. Knowledge of the relationships between patient size, dose and image noise are important for CT patient dose optimisation. In this study, the CT patient doses were surveyed for 14 CT scanners from four different CT scanner manufacturers. The patient cross sectional area, the tube current modulation and the image noise from the CT images were analysed using in-house software. The Toshiba and GE scanner results showed that noise levels are relatively constant but tube currents are dependent on patient size. As a result of this there is a wide range in tube current values across different patient sizes, and doses for large patients are significantly higher in these scanners. In contrast, in the Philips and Siemens scanners, tube currents are less dependent on patient size, the range in tube current is narrower, and the doses for larger patients are not as high. Image noise is more dependent on the patient size. (paper)

  4. Automatic tube current modulation for volume scan in a 320-detector row CT scanner

    International Nuclear Information System (INIS)

    The x-y plane combined with z-axis automatic tube current modulation (ATCM) technique is one of the most comprehensive approaches to CT dose reduction because the radiation dose is adjusted according to patient attenuation in three dimensions. The 320-detector row CT scanner has the widest scan range (16 cm) within one axial rotation and equips with volume scan ATCM (VS-ATCM) mode. Special attention is needed while utilizing VS-ATCM mode in CT acquisitions especially scanning different anatomical regions, such as neck and shoulder in a single volume. However, the mechanism of VS-ATCM of the 320-detector row CT scanner remains unclear. This study aims to evaluate the performance of VS-ATCM mode in a 320-detector row CT scanner. A phantom set consists of three simple-shaped phantoms was scanned with the VS-ATCM mode. A solid-state detector was inserted into the central position of the phantom set to measure the real-time dose profiles at seven positions within five scan volumes. The effective tube-current time product of each slice was recorded. The standard deviation of the CT numbers measured at each image slice was used as a noise measurement. The performance of helical scan ATCM (HS-ATCM) mode was in comparison of VS-ATCM mode. The results indicated that VS-ATCM mode can provide a less dose CT scanning to a patient but resulted in a higher image noise in comparison with those of HS-ATCM mode. In clinical practice, radiologists or radiological technologists should pay more attention on the volume position when using VS-ATCM mode for patient imaging. Our experience can be a reference to others for implementation of clinical practices. -- Highlights: •Real-time dose profiles were measured for volume-scan ATCM mode. •Comparison of tube current variation between volume- and helical-scan ATCM modes. •Comparison of image noise between volume- and helical-scan ATCM modes

  5. Size-based protocol optimization using automatic tube current modulation and automatic kV selection in computed tomography.

    Science.gov (United States)

    MacDougall, Robert D; Kleinman, Patricia L; Callahan, Michael J

    2016-01-01

    Size-based diagnostic reference ranges (DRRs) for contrast-enhanced pediatric abdominal computed tomography (CT) have been published in order to establish practical upper and lower limits of CTDI, DLP, and SSDE. Based on these DRRs, guidelines for establishing size-based SSDE target levels from the SSDE of a standard adult by applying a linear correction factor have been published and provide a great reference for dose optimization initiatives. The necessary step of designing manufacturer-specific CT protocols to achieve established SSDE targets is the responsibility of the Qualified Medical Physicist. The task is straightforward if fixed-mA protocols are used, however, more difficult when automatic exposure control (AEC) and automatic kV selection are considered. In such cases, the physicist must deduce the operation of AEC algorithms from technical documentation or through testing, using a wide range of phantom sizes. Our study presents the results of such testing using anthropomorphic phantoms ranging in size from the newborn to the obese adult. The effect of each user-controlled parameter was modeled for a single-manufacturer AEC algorithm (Siemens CARE Dose4D) and automatic kV selection algorithm (Siemens CARE kV). Based on the results presented in this study, a process for designing mA-modulated, pediatric abdominal CT protocols that achieve user-defined SSDE and kV targets is described. PMID:26894344

  6. INFLUENCE OF LOCALIZER AND SCAN DIRECTION ON THE DOSE-REDUCING EFFECT OF AUTOMATIC TUBE CURRENT MODULATION IN COMPUTED TOMOGRAPHY.

    Science.gov (United States)

    Franck, C; Bacher, K

    2016-06-01

    The purpose of this study was to investigate the influence of the localizer and scan direction on the dose-reducing efficacy of the automatic tube current modulation (ATCM) in computed tomography (CT). Craniocaudal and caudocranial chest CT scans, based on anterior-posterior (AP), posterior-anterior (PA), lateral (LAT) or dual AP/LAT localizers, of an anthropomorphic phantom containing thermoluminescent dosimeters (TLDs), were made on three Siemens systems. TLD readings were converted to lung and thyroid doses. A second dose estimation was performed based on Monte Carlo simulations. In addition, the ATCM behaviour of GE and Toshiba was evaluated based on AP, PA and LAT localizers. Compared with AP, tube currents of PA and AP/LAT scans were on average 20 % higher and 40 % lower, respectively, for the Siemens systems. Consequently, thyroid and lung doses increased with 60 % with a PA instead of an AP/LAT scan, with significant differences in image noise. Moreover, the thyroid dose halves by taking the scan in caudocranial direction. Noise values were not significantly different when changing scan direction. PMID:27056145

  7. Automatic exposure control in multichannel CT with tube current modulation to achieve a constant level of image noise: Experimental assessment on pediatric phantoms

    International Nuclear Information System (INIS)

    Automatic exposure control (AEC) systems have been developed by computed tomography (CT) manufacturers to improve the consistency of image quality among patients and to control the absorbed dose. Since a multichannel helical CT scan may easily increase individual radiation doses, this technical improvement is of special interest in children who are particularly sensitive to ionizing radiation, but little information is currently available regarding the precise performance of these systems on small patients. Our objective was to assess an AEC system on pediatric dose phantoms by studying the impact of phantom transmission and acquisition parameters on tube current modulation, on the resulting absorbed dose and on image quality. We used a four-channel CT scan working with a patient-size and z-axis-based AEC system designed to achieve a constant noise within the reconstructed images by automatically adjusting the tube current during acquisition. The study was performed with six cylindrical poly(methylmethacrylate) (PMMA) phantoms of variable diameters (10-32 cm) and one 5 years of age equivalent pediatric anthropomorphic phantom. After a single scan projection radiograph (SPR), helical acquisitions were performed and images were reconstructed with a standard convolution kernel. Tube current modulation was studied with variable SPR settings (tube angle, mA, kVp) and helical parameters (6-20 HU noise indices, 80-140 kVp tube potential, 0.8-4 s. tube rotation time, 5-20 mm x-ray beam thickness, 0.75-1.5 pitch, 1.25-10 mm image thickness, variable acquisition, and reconstruction fields of view). CT dose indices (CTDIvol) were measured, and the image quality criterion used was the standard deviation of the CT number measured in reconstructed images of PMMA material. Observed tube current levels were compared to the expected values from Brooks and Di Chiro's [R.A. Brooks and G.D. Chiro, Med. Phys. 3, 237-240 (1976)] model and calculated values (product of a reference value

  8. Iterative reconstruction and individualized automatic tube current selection reduce radiation dose while maintaining image quality in 320-multidetector computed tomography coronary angiography

    International Nuclear Information System (INIS)

    Aim: To assess the effect of two iterative reconstruction algorithms (AIDR and AIDR3D) and individualized automatic tube current selection on radiation dose and image quality in computed tomography coronary angiography (CTCA). Materials and methods: In a single-centre cohort study, 942 patients underwent electrocardiogram-gated CTCA using a 320-multidetector CT system. Images from group 1 (n = 228) were reconstructed with a filtered back projection algorithm (Quantum Denoising Software, QDS+). Iterative reconstruction was used for group 2 (AIDR, n = 379) and group 3 (AIDR3D, n = 335). Tube current was selected based on body mass index (BMI) for groups 1 and 2, and selected automatically based on scout image attenuation for group 3. Subjective image quality was graded on a four-point scale (1 = excellent, 4 = non-diagnostic). Results: There were no differences in age (p = 0.975), body mass index (p = 0.435), or heart rate (p = 0.746) between the groups. Image quality improved with iterative reconstruction and automatic tube current selection [1.3 (95% confidence intervals (CI): 1.2–1.4), 1.2 (1.1–1.2) and 1.1 (1–1.2) respectively; p < 0.001] and radiation dose decreased [274 (260–290), 242 (230–253) and 168 (156–180) mGy cm, respectively; p < 0.001]. Conclusion: The application of the latest iterative reconstruction algorithm and individualized automatic tube current selection can substantially reduce radiation dose whilst improving image quality in CTCA

  9. Method for Automatic Tube Current Selection for Obtaining a Consistent Image Quality and Dose Optimization in a Cardiac Multidetector CT

    OpenAIRE

    Qi, Weiwei; Li, Jianying; Du, Xiangke

    2009-01-01

    Objective To evaluate a quantitative method for individually adjusting the tube current to obtain images with consistent noise in electrocardiogram (ECG)-gated CT cardiac scans. Materials and Methods The image noise from timing bolus and cardiac CT scans of 80 patients (Group A) who underwent a 64-row multidetector (MD) CT cardiac examination with patient-independent scan parameters were analyzed. A formula was established using the noise correlation between the timing bolus and cardiac scans...

  10. Automatic exposure control in CT: the effect of patient size, anatomical region and prescribed modulation strength on tube current and image quality

    Energy Technology Data Exchange (ETDEWEB)

    Papadakis, Antonios E. [University Hospital of Heraklion, Department of Medical Physics, Stavrakia, P.O. Box 1352, Heraklion, Crete (Greece); Perisinakis, Kostas; Damilakis, John [University of Crete, Faculty of Medicine, Department of Medical Physics, P.O. Box 2208, Heraklion, Crete (Greece)

    2014-10-15

    To study the effect of patient size, body region and modulation strength on tube current and image quality on CT examinations that use automatic tube current modulation (ATCM). Ten physical anthropomorphic phantoms that simulate an individual as neonate, 1-, 5-, 10-year-old and adult at various body habitus were employed. CT acquisition of head, neck, thorax and abdomen/pelvis was performed with ATCM activated at weak, average and strong modulation strength. The mean modulated mAs (mAs{sub mod}) values were recorded. Image noise was measured at selected anatomical sites. The mAs{sub mod} recorded for neonate compared to 10-year-old increased by 30 %, 14 %, 6 % and 53 % for head, neck, thorax and abdomen/pelvis, respectively, (P < 0.05). The mAs{sub mod} was lower than the preselected mAs with the exception of the 10-year-old phantom. In paediatric and adult phantoms, the mAs{sub mod} ranged from 44 and 53 for weak to 117 and 93 for strong modulation strength, respectively. At the same exposure parameters image noise increased with body size (P < 0.05). The ATCM system studied here may affect dose differently for different patient habitus. Dose may decrease for overweight adults but increase for children older than 5 years old. Care should be taken when implementing ATCM protocols to ensure that image quality is maintained. circle ATCM efficiency is related to the size of the patient's body. (orig.)

  11. A study of CT dose distribution in an elliptical phantom and the influence of automatic tube current modulation in the x-y plane.

    Science.gov (United States)

    Sookpeng, S; Martin, C J; Gentle, D J

    2013-06-01

    Computed tomography (CT) performance assessments relating to patient dose to the body are made conventionally in 320 mm diameter cylindrical acrylic phantoms. The cross section of the human trunk is closer to an ellipse and automatic tube current modulation (ATCM) systems adjust the exposure level with orientation in the x-y plane, changing the dose distribution within the body. This study has investigated differences in the distributions of dose within a standard cylindrical body phantom and an elliptical dosimetry phantom for Toshiba, General Electric and Philips CT scanners, and recorded changes with the application of the ATCM. Single slice dose profiles have been recorded within the phantoms using Gafchromic film. CT dose indices along 100 mm lengths have been calculated and data sets combined to simulate helical scans, from which values for cumulative doses have been derived. The doses in the centre of the elliptical phantom are 70-100% larger than for the cylindrical one and in the anterior are around 20-40% larger, while the doses in the lateral positions are similar for the two phantom shapes. The differences between the anterior and lateral doses were larger for the Toshiba scanner and this is thought to be linked to the narrower profile of the beam produced by the bow-tie filter. When the ATCM mode for the Toshiba scanner is implemented, the doses in the anterior and posterior positions are reduced preferentially, bringing them closer to the doses in the lateral positions. PMID:23676349

  12. The application of automatic tube current modulation (ATCM) on image quality and radiation dose at abdominal computed tomography (CT): A phantom study.

    Science.gov (United States)

    Wang, Qian; Zhao, Xinming; Song, Junfeng; Guo, Ning; Zhu, Ying; Liu, Jianxin; Qi, Weiwei; Wu, Jing; Liang, Yuan; Feng, Shichao; Hu, Mancang; Zhou, Chunwu; Wang, Xiaoying; Hong, Nan

    2013-01-01

    Multi-phase spiral Computed tomography (CT) of abdomen has been widely used as an effective imaging modality to diagnose variety of diseases. As a result, the accumulated radiation exposure on the abdomen is substantially higher than other human organ regions. According to ALARA (as low as reasonably achievable) principle, how to control radiation dose without compromising imaging quality becomes a research topic of high interest. However, how to achieve dose optimization of the abdomen CT examinations in Chinese patients have not been fully investigated in previous studies. In this study, we develop an abdomen-equivalent tissue model made by well-known CTP579 auxiliary testing model and the real CT data acquired from 68 Chinese male subjects. Combining with catphan600, we simulated the visibility of low and high contrast objects at adult abdomen under variety of x-ray dose levels. Using the automatic tube current modulation (ATCM) technique, we reduced the total radiation dose and identified a proper noise index (NI) for Chinese patients to maintain low or high contrast detectability of abdominal CT image. Our numerical experiments showed that in the phantom study for Chinese patients, when a NI was set at 10, the radiation dose reduced by 34.3% with low contrast objects detectable, while setting NI at 14 the dose level decreased by 65.1% without change the detectability of high contrast targets. The subjective ratings from three radiologists also yielded high consistence with Kappa > 0.75. This study demonstrated the feasibility of performing the CT dose optimization studies through a unique phantom with the ATCM method.

  13. Ionization tube simmer current circuit

    Science.gov (United States)

    Steinkraus, Jr., Robert F.

    1994-01-01

    A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current.

  14. Eddy current inspection of tubing

    International Nuclear Information System (INIS)

    The Experimental research work carried out to develop a Eddy current testing equipment is described. Search coils with ferrite or air cores were used and the obtained results are discussed. Valuable information was gained from a improved channel in which a direct measure of the defect and the reference signal phase difference is obtained. Artificial defect used to evaluate resolution and sensitivity were produced by electro-machining and mechanical means. Finned SAP tubing was tested in a routine basis with the described equipment and the results plotted. Basic and theoretical considerations on the Eddy current testing technique are given in the last section of this report. (Author)

  15. HIGH CURRENT COAXIAL PHOTOMULTIPLIER TUBE

    Science.gov (United States)

    Glass, N.W.

    1960-01-19

    A medium-gain photomultiplier tube having high current output, fast rise- time, and matched output impedance was developed. The photomultiplier tube comprises an elongated cylindrical envelope, a cylindrical anode supported at the axis of the envelope, a plurality of elongated spaced opaque areas on the envelope, and a plurality of light admitting windows. A photo-cathode is supported adjacent to each of the windows, and a plurality of secondary emissive dynodes are arranged in two types of radial arrays which are alternately positioned to fill the annular space between the anode and the envelope. The dynodes are in an array being radially staggered with respect to the dynodes in the adjacent array, the dynodes each having a portion arranged at an angle with respect to the electron path, such that electrons emitted by each cathode undergo multiplication upon impingement on a dynode and redirected flight to the next adjacent dynode.

  16. Eddy current tube testing unit

    International Nuclear Information System (INIS)

    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

  17. The TS 600: automatic control system for eddy currents

    International Nuclear Information System (INIS)

    In the scope of fabrication and in service inspection of the PWR steam generator tubing bendle, FRAMATOME developed an automatic Eddy Current testing system: TS600. Based on a mini-computer, TS600 allows to digitize, to store and to process data in various ways, so it is possible to perform several kinds of inspection: conventional inservice inspection, roll area profilometry...... TS600 can also be used to develop new methods of examination

  18. Automatic integrated testing bench for tubes in translation

    International Nuclear Information System (INIS)

    All the nondestructive tests required for receiving the cladding tubes intended for fast nuclear reactor are integrated on this bench: quality control by eddy currents and ultra-sounds, thickness and (inner and outer) diameter measurement. The linear displacement of the tube allows very high rates to be attained

  19. 多层螺旋CT自动管电流调制技术及应用进展%Automatic Tube Current Modulation Techniques in Multi-slice CT Scanning and the Application Progress

    Institute of Scientific and Technical Information of China (English)

    王倩

    2013-01-01

    随着计算机X线断层扫描(CT)技术的普及,CT扫描的高辐射剂量日益得到广泛关注.CT低剂量研究也成为了CT研究的热点领域.目前,降低CT扫描剂量的方法众多,而自动管电流调制技术(ATCM)作为一项通过实时曝光控制优化辐射剂量兼顾图像质量的先进技术已在临床工作中应用.不同的设备各有其技术基本原理及指标.对ATCM技术在头颈、胸、腹、盆腔部位应用及其影响因素和局限性等尚需更多的临床研究和改进.%With the popularization of CT scanning technology,high radiation dose has drawn wide attention, and low-dose CT has become the hot field. Jnowdays,many methods could be used to reduce CT radiation dose. Automatic tube current modulationt (ATCM ) technique, an advanced technology, has been applied in the clinical which optimizes radiation dose through real-time exposure control with the guaranty for image quality. Different equipments have different working principles and indicators, and the application of ATCM technique in head and neck, thorax, abdomen, pelvic cavity and the influencers and limitations still need further clinical research and improvement.

  20. Automatic measuring system of zirconium thickness for zirconium liner cladding tubes

    International Nuclear Information System (INIS)

    An automatic measuring system of pure zirconium liner thickness for Zirconium-Zircaloy cladding tubes has been successfully developed. The system consists of three parts. An ultrasonic thickness measuring method for mother tubes before cold rolling; an electromagnetic thickness measuring method for the manufactured tubes, and, an image processing method for the cross sectional view of the manufactured cut tube samples

  1. Circle Points Discharge Tube Current Controller

    Institute of Scientific and Technical Information of China (English)

    Meng Jinjia; Meng Lisheng

    2005-01-01

    Circle points discharge tube current controller is a new type device to limit theoutput of high voltage discharge current. Circle points uniform corona discharge to form airionization current in the discharge tube. On the outside, even if the discharge electrode is sparkdischarging or the two discharge electrodes are short circuited, the air ionization current in the tuberemains within a stable range, and there is no spark discharge. In this case, when the dischargecurrent only increases slightly, the requirement to limited current is obtained. By installing thecontroller at a discharge pole with a small power but high voltage supply, we can realize the shiftbetween the continuous spark line discharge and corona discharge. This provides a new simpledevice for spark discharge research and is a supplement to the Townsend discharge experiment.

  2. Tube current reduction in pediatric non-ECG-gated heart CT by combined tube current modulation

    International Nuclear Information System (INIS)

    Dose reduction by combined tube current modulation has not been evaluated in pediatric low-dose CT. This study was performed to evaluate tube current reduction in non-ECG-gated heart CT angiography in children by combined tube current modulation, and to assess the effects of body weight, age, sex, and scan direction on tube current reduction. From September 2004 to January 2005, non-ECG-gated heart CT examinations were performed with combined tube current modulation in 50 children (median age 1 year, range 1 month to 16 years; M/F 29/21) with congenital heart disease. Sixteen-slice spiral CT studies were obtained using a weight-based low-dose protocol (80 kVp, 50-160 effective mA). CT scans were obtained in the craniocaudal direction when leg veins (n=36) were used for IV injection of contrast agent and in the caudocranial direction when arm veins (n=13) were used. In one child who underwent a Fontan operation, both arm and leg veins were used. We calculated tube current reduction by combined tube current modulation and evaluated the effects of body weight, age, sex, and scan technique on tube current reduction. The quality of CT angiography images was visually evaluated by an experienced pediatric radiologist. Overall tube current reduction by combined tube current modulation was 15.8±11.1%. The reduction was variable among five body weight groups (9.3±7.9% for <4.9 kg, 14.3±9.3% for 5.0-9.9 kg, 16.4±12.5% for 10.0-19.9 kg, 25.8±9.8% for 20.0-39.9 kg, 15.9±12.7% for 40.0-59.9 kg) and was significantly different among the five groups (P=0.017). When eight children in the 40.0-59.9-kg group were excluded, age showed a significant positive correlation with tube current reduction (γ=0.4, P=0.003). There was no significant difference in tube current reduction between boys and girls. Tube current reduction was significantly greater for the caudocranial scan (21.2±9.2%) than for the craniocaudal scan (14.2±11.3%) (P=0.049). All CT angiography images were of

  3. Thin tube testing by eddy currents

    International Nuclear Information System (INIS)

    It is often necessary to define test conditions in eddy current testing, in consequence rules and laws allowing a rapid choice of these conditions are welcome. The similarity law, given by Forster, using the reduced frequency f/fg, allows extrapolation of results from an object to one another, if these two objects are similar (i.e. all their dimensions are proportional). In a particular case, often met, a law going further is given to describe, in a sole way, eddy current behaviour using the reduced frequency in all thin tubes (internal to external diameter ratio between 0.85 to 1). For instance working at f/fe=2 defines the same verification leading to identical results, whatever the nature, the diameter or the thickness may be, if the tubes are thin. A diagram is given and a slide-rule, based on this principle, has been realized

  4. An improved automatic computer aided tube detection and labeling system on chest radiographs

    Science.gov (United States)

    Ramakrishna, Bharath; Brown, Matthew; Goldin, Jonathan; Cagnon, Christopher; Enzmann, Dieter

    2012-03-01

    Tubes like Endotracheal (ET) tube used to maintain patient's airway and the Nasogastric (NG) tube used to feed the patient and drain contents of the stomach are very commonly used in Intensive Care Units (ICU). The placement of these tubes is critical for their proper functioning and improper tube placement can even be fatal. Bedside chest radiographs are considered the quickest and safest method to check the placement of these tubes. Tertiary ICU's typically generate over 250 chest radiographs per day to confirm tube placement. This paper develops a new fully automatic prototype computer-aided detection (CAD) system for tube detection on bedside chest radiographs. The core of the CAD system is the randomized algorithm which selects tubes based on their average repeatability from seed points. The CAD algorithm is designed as a 5 stage process: Preprocessing (removing borders, histogram equalization, anisotropic filtering), Anatomy Segmentation (to identify neck, esophagus, abdomen ROI's), Seed Generation, Region Growing and Tube Selection. The preliminary evaluation was carried out on 64 cases. The prototype CAD system was able to detect ET tubes with a True Positive Rate of 0.93 and False Positive Rate of 0.02/image and NG tubes with a True Positive Rate of 0.84 and False Positive Rate of 0.02/image respectively. The results from the prototype system show that it is feasible to automatically detect both tubes on chest radiographs, with the potential to significantly speed the delivery of imaging services while maintaining high accuracy.

  5. Automatic ultrasonic system for flaw detection and dimensional measurement of precision tubes

    International Nuclear Information System (INIS)

    This paper describes a system, which is installed at Nuclear Fuel Complex, Hyderabad. It is a tube rotation fixed probe type of system designed for fully automatic operation at high speed using immersion technique for ultrasonic flaw detection and dimensional measurement of precision of zirconium alloy seamless tubes used in fuel bundles for nuclear reactors

  6. Automatic all position welding for horizontally fixed tubes by tungsten inert gas arc welding method

    International Nuclear Information System (INIS)

    The welding of fixed tubes is mostly all position welding in restricted places, accordingly much skill is required. The automation of welding is necessary because of the requirement for the reliability of welded joints, the difficulty of securing skilled workers, and welding quality. The development and production of the automatic welders for TIG welding of tubes have been carried out by Mitsubishi Electric Corp., and the application to various purposes was attempted. The TIG welding for the automatic welding of tubes is advantageous, because backside bead can be formed stably, spatter does not arise, welding is stable for every metal, and the mechanism of the automatic welders is simple. But it is not suitable for the welding of zinc-plated tubes, and the rate of deposition is relatively small. It is applied to the welding of boiler tubes, nuclear energy equipments and pipings, chemical equipments and pipings, and aluminum pipings. The specifications and the construction of the TIG tube welders are shown. The preparation of joints and the control of welding conditions are important for guaranteeing the welding results in automatic welding, therefore sufficient consultation with welder makers about these points is required. The welding defects apt to arise are the bad form of backside beads, blowholes, and the insufficient melting of intermediate layers, and the countermeasures to them must be taken. (Kako, I.)

  7. Automatic measuring system of zirconium thickness for zirconium liner cladding tubes

    International Nuclear Information System (INIS)

    An automatic system of pure zirconium liner thickness for zirconium-zircaloy cladding tubes has been successfully developed. The system consists of three parts. (1) An ultrasonic thickness measuring method for mother tubes before cold rolling. (2) An electromagnetic thickness measuring method for the manufactured tubes. (3) An image processing method for the cross sectional view of the manufactured cut tube samples. In Japanese nuclear industry, zirconium-zircaloy cladding tubes have been tested in order to realize load following operation in the atomic power plant. In order to provide for the practical use in the near future, Sumitomo Metal Industries, Ltd. has been studied and established the practical manufacturing process of the zirconium liner cladding tubes. The zirconium-liner cladding tube is a duplex tube comprising an inner layer of pure zirconium bonded to zircaloy metallurgically. The thickness of the pure zirconium is about 10 % of the total wall thickness. Several types of the automatic thickness measuring methods have been investigated instead of the usual microscopic viewing method in which the liner thickness is measured by the microscopic cross sectional view of the cut tube samples

  8. Prediction of extubation outcome: a randomised, controlled trial with automatic tube compensation vs. pressure support ventilation

    OpenAIRE

    Cohen, Jonathan; Shapiro, Maury; Grozovski, Elad; Fox, Ben; Lev, Shaul; Singer, Pierre

    2009-01-01

    Introduction Tolerance of a spontaneous breathing trial is an evidence-based strategy to predict successful weaning from mechanical ventilation. Some patients may not tolerate the trial because of the respiratory load imposed by the endotracheal tube, so varying levels of respiratory support are widely used during the trial. Automatic tube compensation (ATC), specifically developed to overcome the imposed work of breathing because of artificial airways, appears ideally suited for the weaning ...

  9. Multifrequency eddy current testing of helical tubes of steam generators

    International Nuclear Information System (INIS)

    In the event of a water-sodium reaction in a steam-generator of a fast breeder reactor, it is necessary to test the tubes close to the leak to evaluate the damage. In SUPERPHENIX, the tubes are about 100m long and are coiled on a dead body. This report describes the equipment and the technic to test such tubes with multifrequency eddy current technics

  10. Automatic selection of tube potential for radiation dose reduction in CT: A general strategy

    International Nuclear Information System (INIS)

    Purpose: To optimize radiation dose efficiency in CT while maintaining image quality, it is important to select the optimal tube potential. The selection of optimal tube potential, however, is highly dependent on patient size and diagnostic task. The purpose of this work was to develop a general strategy that allows for automatic tube potential selection for each individual patient and each diagnostic task. Methods: The authors propose a general strategy that allows automatic adaptation of the tube potential as a function of patient size and diagnostic task, using a novel index of image quality, ''iodine contrast to noise ratio with a noise constraint (iCNRNC),'' to characterize the different image quality requirements by various clinical applications. The relative dose factor (RDF) at each tube potential to achieve a target image quality was then determined as a function of patient size and the noise constraint parameter. A workflow was developed to automatically identify the optimal tube potential that is both dose efficient and practically feasible, incorporating patient size and diagnostic task. An experimental study using a series of semianthropomorphic thoracic phantoms was used to demonstrate how the proposed general strategy can be implemented and how the radiation dose reduction achievable by the tube potential selection depends on phantom sizes and noise constraint parameters. Results: The proposed strategy provides a flexible and quantitative way to select the optimal tube potential based on the patient size and diagnostic task. The noise constraint parameter α can be adapted for different clinical applications. For example, α=1 for noncontrast routine exams; α=1.1-1.25 for contrast-enhanced routine exams; and α=1.5-2.0 for CT angiography. For the five thoracic phantoms in the experiment, when α=1, the optimal tube potentials were 80, 100, 100, 120, 120, respectively. The corresponding RDFs (relative to 120 kV) were 78.0%, 90.9%, 95.2%, 100%, and

  11. Eddy current detection of corrosion damage in heat exchanger tubes

    International Nuclear Information System (INIS)

    Eddy current is often the most effective nondestructive test method available for in-service inspection of small bore tubing in heat exchangers. The basic principles, advantages and shortcomings of the technique are outlined. Typical eddy current indications from corrosion-related defects such as stress corrosion cracks, pitting and tube denting under support plates are presented. Eddy current signals from features such as magnetite deposits and ferromagnetic inclusions which might be mistaken for defects are also discussed. (auth)

  12. Automatic analysis of signals during Eddy currents controls

    International Nuclear Information System (INIS)

    A method and the corresponding instrument have been developed for automatic analysis of Eddy currents testing signals. This apparatus enables at the same time the analysis, every 2 milliseconds, of two signals at two different frequencies. It can be used either on line with an Eddy Current testing instrument or with a magnetic tape recorder

  13. Remote field eddy current testing of ferromagnetic tubes

    International Nuclear Information System (INIS)

    In order to test ferromagnetic tubes using internal probes, Intercontrole and the CEA have carried out theoretical and experimental works and developed a method to adapt the Remote Field Eddy Current technique which has been known and used for 30 years now. This document briefly recalls the basic principles of the Remote Field Eddy Current technique, the various steps of the works carried out and mainly describes examples of field inspection of ferromagnetic tubes and pipes

  14. GTSP, automatic ultrasonic inspection of Guide Tube Support Pin in nuclear power plants

    International Nuclear Information System (INIS)

    1 - Description of program or function: GTSP Visitor is a program for automatic detection of known object's position in video frames. It is especially designed for automatic ultrasonic inspection of guide tube support pin (GTSP) in nuclear power plant. 2 - Methods: A GTSP and its position are detected by two-step matched filter algorithm. In first step, a video frame including GTSPs are transformed by DFT. DFTed image is multiplied by matched filter, made from a guide tube image, in frequency domain for estimate Guide Tube center position. Guide Tube areas around estimated center position are erased (pixel values of image are filled with zeros). In next step, image whose guide tube areas were erased is processed as described above but using a different matched filter made from a support pin?s image. Then the positions of two GTSPs are estimated and their orientation is estimated too. Finally its position and orientations are used for control the robot toward the desired position. 3 - Restrictions on the complexity of the problem: Robot control is out of the scope of this program. OpenCV and compatible camera are necessary

  15. Eddy current inspection of mildly ferromagnetic tubing

    International Nuclear Information System (INIS)

    The past decade has seen the development of eddy current probes for inspection of the mildly ferro-magnetic alloy Monel 400. Due to the rapid advances in permanent magnet technology similar probes have been upgraded to magnetically saturate, and hence inspect, the duplex stainless steel Sandvik 3RE60, which has saturation induction more than twice that of Monel 400. Prototypes of these probes have been tested in three ways: saturation capability, quality of typical eddy current data, and ability to eliminate permeability induced signals. Successful laboratory testing, potential applications, and limitations of these type probes are discussed

  16. Testing and analysis of tube voltage and tube current in the radiation generator for mammography

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Hong Ryang; Hong, Dong Hee [Dept. of Health Care, Hanseo University, Seosan (Korea, Republic of); Han, Beom Hui [Dept. of Radiological Science, Seonam University, Namwon (Korea, Republic of)

    2014-03-15

    Breast shooting performance management and quality control of the generator is applied to the amount of current IEC(International Electrotechnical Commission) 60601-2-45 tube voltage and tube current are based on standards that were proposed in the analysis of the test results were as follows. Tube voltage according to the value of the standard deviation by year of manufacture from 2001 to 2010 as a 42-3.15 showed the most significant, according to the year of manufacture by tube amperage value of the standard deviation to 6.38 in the pre-2000 showed the most significant , manufactured after 2011 the standard deviation of the devices, the PAE(Percent Average Error) was relatively low. This latest generation device was manufactured in the breast of the tube voltage and tube diagnosed shooting the correct amount of current to maintain the performance that can be seen. The results of this study as the basis for radiography diagnosed breast caused by using the device's performance and maintain quality control, so the current Food and Drug Administration 'about the safety of diagnostic radiation generator rule' specified in the test cycle during three years of self-inspection radiation on a radiation generating device ensure safety and performance of the device using a coherent X-ray(constancy) by two ultimately able to keep the radiation dose to the public to reduce the expected effect is expected.

  17. Automatic system for measuring the zirconium liner and Zircaloy-2 thickness of zirconium liner tubes

    International Nuclear Information System (INIS)

    This paper reports on an automatic system to measure the zirconium liner thickness and Zircaloy-2 thickness of Zircaloy tubes with a zirconium liner for nuclear reactors. This system uses an electromagnetic probe connected to a data processing unit for measuring the liner thickness, an ultrasonic inspection system for measuring the wall-thickness, and a computer for calculating the Zircaloy-2 thickness from the liner thickness and wall-thickness. Fully automatic measurements on zirconium liner thickness and Zircaloy-2 thickness are performed with high accuracy to an order of 2 μm. This newly developed system is very useful in assuring the liner layer and Zircaloy-2 thickness in the production of high-quality cladding tubes

  18. Clinical evaluation of automatic tube voltage selection in chest CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Niemann, Tilo; Henry, Simon; Faivre, Jean-Baptiste; Yasunaga, Kanna; Bendaoud, Sofiane; Simeone, Ariana; Remy, Jacques [University Lille Nord de France, Department of Thoracic Imaging, Hospital Calmette (EA 2694), Lille (France); Duhamel, Alain [University Lille Nord de France, Department of Medical Statistics (EA 2694), Lille (France); Flohr, Thomas [Siemens Medical Systems, Department of Research and Development, Forchheim (Germany); Remy-Jardin, Martine [Hospital Calmette, Department of Thoracic Imaging, Lille cedex (France)

    2013-10-15

    To evaluate the clinical impact of automatic tube voltage selection on chest CT angiography (CTA). Ninety-three patients were prospectively evaluated with a CT protocol aimed at comparing two successive CTAs acquired under similar technical conditions except for the kV selection: (1) the initial CTA was systematically obtained at 120 kVp and 90 ref mAs; (2) the follow-up CTA was obtained with an automatic selection of the kilovoltage (Care KV; Siemens Healthcare) for optimised CTA. At follow-up, 90 patients (97 %) underwent CTA with reduced tube voltage, 100 kV (n = 26; 28 %) and 80 kV (n = 64; 69 %), resulting in a significant dose-length-product reduction (follow-up: 87.27; initial: 141.88 mGy.cm; P < 0.0001; mean dose reduction: 38.5 %) and a significant increase in the CNR at follow-up (follow-up: 11.5 {+-} 3.5 HU; initial: 10.9 {+-} 3.7 HU; P = 0.03). The increase in objective image noise at follow-up (follow-up: 23.2 {+-} 6.7 HU vs. 17.8 {+-} 5.1 HU; P < 0.0001) did not alter the diagnostic value of images. Automatic tube voltage selection reduced the radiation dose delivered during chest CT angiograms by 38.5 % while improving the contrast-to-noise ratio of the examinations. (orig.)

  19. Automatic welding of stainless steel instrumentation tubing in a nuclear power station

    International Nuclear Information System (INIS)

    Impulse lines and sample lines associated with instrumentation systems are of pipes and tubes. For this purpose, stainless steel tubes are employed in CANDU type reactors. For joints, wherever necessary, welding is preferred to tube fittings as far as possible. Welding is less costly, requires less space and is less likely to be disturbed by the operator. For welding, an automatic weld machine is used. Essential parts of this machine, namely, power supply, logic circuits, speed control unit, handle, weld head, high frequency unit, pendant box, recorder and gas system are described. Sequence of operation is explained. Procedures of machine testing, quality control and inspection, and maintenance problems are given. Qualifications for operator are enumerated. Problems in maintenance are reported. (M.G.B.)

  20. Development of and experience with automatically operated ultrasonic wall thickness gauging for periodic inspection of heat exchanger tube bundles

    International Nuclear Information System (INIS)

    The demand for an accurate inservice inspection method for ferritic LMFBR steam generator tube bundles resulted in a fast and automatic operating system based upon ultrasonics, which appears suitable for nearly all kinds of heat exchangers. (author)

  1. Application of automatic inspection system to nondestructive test of heat transfer tubes of primary pressurized water cooler in the high temperature engineering test reactor. Joint research

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Takeshi; Furusawa, Takayuki [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Miyamoto, Satoshi [Japan Atomic Power Company, Tokyo (Japan)

    2001-07-01

    Heat transfer tubes of a primary pressurized water cooled (PPWC) in the high temperature engineering test reactor (HTTR) form the reactor pressure boundary of the primary coolant, therefore are important from the viewpoint of safety. To establish inspection techniques for the heat transfer tubes of the PPWC, an automatic inspection system was developed. The system employs a bobbin coil probe, a rotating probe for eddy current testing (ECT) and a rotating probe for ultrasonic testing (UT). Nondestructive test of a half of the heat transfer tubes of the PPWC was carried out by the automatic inspection system during reactor shutdown period of the HTTR (about 55% in the maximum reactor power in this paper). The nondestructive test results showed that the maximum signal-to-noise ratio was 1.8 in ECT. Pattern and phase of Lissajous wave, which were obtained for the heat transfer tube of the PPWC, were different from those obtained for the artificially defected tube. In UT echo amplitude of the PPWC tubes inspected was lower than 20% of distance-amplitude calibration curve. Thus, it was confirmed that there was no defect in depth, which was more than the detecting standard of the probes, on the outer surface of the heat transfer tubes of the PPWC inspected. (author)

  2. Investigation of casing inspection through tubing with pulsed eddy current

    Science.gov (United States)

    Fu, Yuewen; Yu, Runqiao; Peng, Xuewen; Ren, Shangkun

    2012-12-01

    Corrosion and cracks of casing string in oil wells is a serious problem on which little research has been done when inspecting casing through tubing. In this study, inspecting casing through tubing with pulsed eddy current is investigated. Longitudinal and transverse probes are centred inside the tubing to detect wall thinnings and cracks in casing. A time slice of induced voltage in the receiving coil of the probe is used as the feature to recognise defects. The experimental results show that large area wall thinnings and long cracks in casing are detected successfully through the tubing with appropriate inspection parameters. The probe's orientation to the crack is important and a particular discovery is that the transverse probe should be parallel to the transverse crack and not be perpendicular to it when inspecting. A method based on linear regression is proposed to estimate flaws in casing while wall thinning in the tubing occurs at the same location. The method is effective for large area thinning in casing when tubing thinning is wide.

  3. Eddy-current inspection of shuttle heat exchanger tube welds

    Science.gov (United States)

    Dodd, Casius V.; Scott, G. W.; Chitwood, L. D.

    1990-01-01

    The goal of this project was to develop the system necessary to demonstrate in the laboratory that an eddy current system can inspect the tubes and welds described, screening for the existence of flaws equal in size to, or larger than, the target flaw. The laboratory system was to include the probe necessary to traverse the tubing, the electronics to drive (i.e., electrically excite) the probe and receive and process signals from it, a data display, data recording, and playback devices, and microprocessor software or firmware necessary to operate the system.

  4. Eddy-current inspection of shuttle heat exchanger tube welds

    International Nuclear Information System (INIS)

    This goal of this project was to develop the system necessary to demonstrate in the laboratory that an eddy-current system can inspect the tubes and welds described above, screening for the existence of flaws equal in size to, or larger than, the target flaw. The laboratory system was to include the probe necessary to traverse the tubing, the electronics to drive (i.e., electrically excite) the probe and receive and process signals from it, a data display, data recording and playback devices, and microprocessor software or firmware necessary to operate the system. 5 refs., 9 figs., 2 tabs

  5. Effect of tube current modulation for dose estimation using a simulation tool on body CT examination

    International Nuclear Information System (INIS)

    The purpose of this study was to evaluate the effect of tube current modulation for dose estimation of a body computed tomography (CT) examination using a simulation tool. The authors also compared longitudinal variations in tube current values between iterative reconstruction (IR) and filtered back-projection (FBP) reconstruction algorithms. One hundred patients underwent body CT examinations. The tube current values around 10 organ regions were recorded longitudinally from tube current information. The organ and effective doses were simulated by average tube current values and longitudinal modulated tube current values. The organ doses for the bladder and breast estimated by longitudinal modulated tube current values were 20 % higher and 25 % lower than those estimated using the average tube current values, respectively. The differences in effective doses were small (mean, 0.7 mSv). The longitudinal variations in tube current values were almost the same for the IR and FBP algorithms. (authors)

  6. Development of an automatized device for eddy current testing

    International Nuclear Information System (INIS)

    To improve performances in eddy current studies, several tools were developed in the Saclay Laboratory: - ELEFANT is a very flexible software which allows a rapid creation of new NDT applications, preserving anytime a full compatibility between computers, applications, data... used under the same ELEFANT controlkey. - Modulo'STA is a modular hardware designed to be the flexible interface between the probe and the computer, driving the measurement, the probe movement... - rotating EC probes with local rotation facilities allow the control of very long steam generator tubes, even bent

  7. Evaluation of the applicability of the tube-type automatic fire extinguishing equipment to the cable fire

    International Nuclear Information System (INIS)

    According to the examination standards related to fire protection for commercial nuclear power reactors and the supplementary facilities issued by Nuclear Regulation Authority in June 2013, a tube-type automatic fire extinguishing system for the cable fire, so called Fire-Erase (FE) system, will be implemented as early warning fire detection and extinction system to mitigate the fire damage to the cable trays for the safe shutdown functions. Therefore, it is necessary to acquire the demonstrative data for fire-extinguishing performance of FE system with respect to the cable tray fire. In this report, the cable fire suppression tests under over-current condition (2000A class) in the horizontal and vertical orientation were executed using the non-heat resistant high voltage power cables and the full-scale cable trays equipped with metal lid covered with fire-resistant sheet to prevent the leakage of fire extinguishing agent, and the effectiveness of the FE system was confirmed. (author)

  8. Adjustment of RVA-62 automatic field-current regulator

    Energy Technology Data Exchange (ETDEWEB)

    Petrov, A.A.; Karkazov, E.I.

    1985-08-01

    While the RVA-62 automatic field-current regulator performs adequately with small and medium-size turbogenerators, its stability margin being often sufficiently large to compensate design inaccuracies, a refinement is nevertheless recommended to ensure reliability under no-load as well as during parallel operation of generators into a common busbar group. The procedure is based on necessary adjustments of over 40 units and applies to redesign, measurements, breadboard simulation, settings, reassembly, and testing. First it is necessary to determine the correct number of primary and secondary turns in the universal controlled phase-compounding transformer, taking into account the parameters of associated equipment (autotransformer, filter choke, power rectifier, current transformer) as well as various modes of generator instability and the use of automatic field suppression. Revisions in testing circuitry and procedure are proposed, including more precise and some extra measurements, also replacement of selenium rectifiers with silicon diodes. Adjustments according to this scheme have been made in the RVA-62 regulators for 6-60 kW generators with VT exciters and 3000-12,000 kW generators, including Skoda, Siemens-Schuckert GmbH, Parsons Ltd units.

  9. Patient specific tube current modulation for CT dose reduction

    Science.gov (United States)

    Jin, Yannan; Yin, Zhye; Yao, Yangyang; Wang, Hui; Wu, Mingye; Kalra, Mannudeep; De Man, Bruno

    2015-03-01

    Radiation exposure during CT imaging has drawn growing concern from academia, industry as well as the general public. Sinusoidal tube current modulation has been available in most commercial products and used routinely in clinical practice. To further exploit the potential of tube current modulation, Sperl et al. proposed a Computer-Assisted Scan Protocol and Reconstruction (CASPAR) scheme [6] that modulates the tube current based on the clinical applications and patient specific information. The purpose of this study is to accelerate the CASPAR scheme to make it more practical for clinical use and investigate its dose benefit for different clinical applications. The Monte Carlo simulation in the original CASPAR scheme was substituted by the dose reconstruction to accelerate the optimization process. To demonstrate the dose benefit, we used the CATSIM package generate the projection data and perform standard FDK reconstruction. The NCAT phantom at thorax position was used in the simulation. We chose three clinical cases (routine chest scan, coronary CT angiography with and without breast avoidance) and compared the dose level with different mA modulation schemes (patient specific, sinusoidal and constant mA) with matched image quality. The simulation study of three clinical cases demonstrated that the patient specific mA modulation could significantly reduce the radiation dose compared to sinusoidal modulation. The dose benefits depend on the clinical application and object shape. With matched image quality, for chest scan the patient specific mA profile reduced the dose by about 15% compared to the sinusoid mA modulation; for the organ avoidance scan the dose reduction to the breast was over 50% compared to the constant mA baseline.

  10. Defect Automatic Identification of Eddy Current Pulsed Thermography

    Directory of Open Access Journals (Sweden)

    Kai Chen

    2014-01-01

    Full Text Available Eddy current pulsed thermography (ECPT is an effective nondestructive testing and evaluation (NDT&E technique, and has been applied for a wide range of conductive materials. Manual selected frames have been used for defects detection and quantification. Defects are indicated by high/low temperature in the frames. However, the variation of surface emissivity sometimes introduces illusory temperature inhomogeneity and results in false alarm. To improve the probability of detection, this paper proposes a two-heat balance states-based method which can restrain the influence of the emissivity. In addition, the independent component analysis (ICA is also applied to automatically identify defect patterns and quantify the defects. An experiment was carried out to validate the proposed methods.

  11. Iterative reconstruction for quantitative computed tomography analysis of emphysema: consistent results using different tube currents

    Directory of Open Access Journals (Sweden)

    Yamashiro T

    2015-02-01

    Full Text Available Tsuneo Yamashiro,1 Tetsuhiro Miyara,1 Osamu Honda,2 Noriyuki Tomiyama,2 Yoshiharu Ohno,3 Satoshi Noma,4 Sadayuki Murayama1 On behalf of the ACTIve Study Group 1Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Nishihara, Okinawa, Japan; 2Department of Radiology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan; 3Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan; 4Department of Radiology, Tenri Hospital, Tenri, Nara, Japan Purpose: To assess the advantages of iterative reconstruction for quantitative computed tomography (CT analysis of pulmonary emphysema. Materials and methods: Twenty-two patients with pulmonary emphysema underwent chest CT imaging using identical scanners with three different tube currents: 240, 120, and 60 mA. Scan data were converted to CT images using Adaptive Iterative Dose Reduction using Three Dimensional Processing (AIDR3D and a conventional filtered-back projection mode. Thus, six scans with and without AIDR3D were generated per patient. All other scanning and reconstruction settings were fixed. The percent low attenuation area (LAA%; < -950 Hounsfield units and the lung density 15th percentile were automatically measured using a commercial workstation. Comparisons of LAA% and 15th percentile results between scans with and without using AIDR3D were made by Wilcoxon signed-rank tests. Associations between body weight and measurement errors among these scans were evaluated by Spearman rank correlation analysis. Results: Overall, scan series without AIDR3D had higher LAA% and lower 15th percentile values than those with AIDR3D at each tube current (P<0.0001. For scan series without AIDR3D, lower tube currents resulted in higher LAA% values and lower 15th percentiles. The extent of emphysema was significantly different between each pair among scans when not using AIDR3D (LAA%, P<0.0001; 15th percentile, P<0.01, but was not

  12. Localization of defects in steam generator tubes using a multi-coil eddy current probe dedicated to high speed inspection

    Energy Technology Data Exchange (ETDEWEB)

    Joubert, P.-Y.; Le Bihan, Y.; Placko, D. [Ecole Normale Superieure de Cachan (France). Laboratoire d' Electricite Signaux et Robotique

    2002-07-01

    Steam generator (SG) tubing of pressurized water reactor in nuclear plants must be rapidly and accurately checked in order to detect defects in their early stages. In this paper, the authors present a multi-coil eddy current (EC) probe allowing both high speed inspection and circumferential localization of defects in the tube wall. A method of multi-coil EC signal processing, based on a continuous wavelet transform combined with a maximum likelihood diagnosis, is elaborated in order to enhance the detection performances and to provide automatic localization of defects. The inspection of SG tube samples shows good localization performances for defects as small as 10% deep, 15 mm long and 100 {mu}m wide outer diameter notches, of both circumferential and axial orientations. (author)

  13. A method and sensor for the eddy current non destructive testing of thin tubes; Procede de controle non destructif d`un tube mince par courants de Foucault

    Energy Technology Data Exchange (ETDEWEB)

    Sartre, B.; Miller, D.; Placko, D.

    1995-06-02

    In order to control the wear (cracking or thinning) of vapor generator tubes, especially in PWR reactors, due to the friction between the tubes and dampers, an eddy current control system is proposed where the transducer is run through the tubes, and measures the tube wall thickness or tube-block clearance through impedance measurements, taking into account the variation of the sensor-to-tube distance. 8 fig.

  14. The Current Situation of Precision Copper Tube Capacity in China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>Precision copper tube generally refers to seam- less copper and copper alloy production tube with high dimension precision,high surface quality,narrow performance range and meeting strict requirements on other general perform- ances such as erosion resistance.These prod-

  15. Improved eddy-current inspection for steam generator tubing

    International Nuclear Information System (INIS)

    Computer programs have been written to allow the analysis of different types of eddy-current probes and their performance under different steam generator test conditions. The probe types include the differential bobbin probe, the absolute bobbin probe, the pancake probe and the reflection probe. The generator test conditions include tube supports, copper deposits, magnetite deposits, denting, wastage, pitting, cracking and IGA. These studies are based mostly on computed values, with the limited number of test specimens available used to verify the computed results. The instrument readings were computed for a complete matrix of the different test conditions, and then the test conditions determined as a function of the readings by a least-squares technique. A comparison was made of the errors in fit and instrument drift for the different probe types. The computations of the change in instrument reading due to the defects have led to an ''inversion'' technique in which the defect properties can be computed from the instrument readings. This has been done both experimentally and analytically for each of these probe types. 3 refs., 13 figs., 1 tab

  16. Current practices for ultrasonic and radiographic examination of tubes, tube plates and tube-plate welds of tube bundles in heat exchangers. Chapter 3

    International Nuclear Information System (INIS)

    The chapter describes the ultrasonic and radiographic inspection procedures that are applied to heat exchanger tube bundles. The inspection process starts with the ultrasonic examination of the tubes and tube plates during manufacture, followed by radiography of the tube-to-tube-plate welds during fabrication of the tube bundle. Ultrasonic methods are explained for welds which are amenable to this type of inspection. For the in-service inspection of tube bundles the chapter relates the authors' experiences on the ultrasonic inspection of tubes and tube plates in the Prototype Fast Breeder Reactor at Dounreay. At the end of the chapter some comments are made about future ultrasonic and radiographic developments for tube bundles. (author)

  17. TU-EF-204-01: Accurate Prediction of CT Tube Current Modulation: Estimating Tube Current Modulation Schemes for Voxelized Patient Models Used in Monte Carlo Simulations.

    OpenAIRE

    McMillan, K; Bostani, M; McCollough, C; McNitt-Gray, M

    2015-01-01

    PURPOSE: Most patient models used in Monte Carlo-based estimates of CT dose, including computational phantoms, do not have tube current modulation (TCM) data associated with them. While not a problem for fixed tube current simulations, this is a limitation when modeling the effects of TCM. Therefore, the purpose of this work was to develop and validate methods to estimate TCM schemes for any voxelized patient model. METHODS: For 10 patients who received clinically-indicated chest (n=5) and ab...

  18. The effect of diffusion on the current-sheet speed in a magnetically driven shock tube

    DEFF Research Database (Denmark)

    Chang, C.T.; Popovic, M.; Korsbech, Uffe

    1970-01-01

    The lowering of the current-sheet speed in a magnetically driven shock tube is attributed to the diffusion effect of the current and not to the anchoring of a large fraction of the total current near the driving end.......The lowering of the current-sheet speed in a magnetically driven shock tube is attributed to the diffusion effect of the current and not to the anchoring of a large fraction of the total current near the driving end....

  19. On-line current feed and computer aided control tactics for automatic balancing head

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In the designed automatic balancing head,a non-contact induction transformer is used to deliver driving energy to solve the problem of current fed and controlling on-line.Computer controlled automatic balancing experiments with phase-magnitude control tactics were performed on a flexible rotor system.Results of the experiments prove that the energy feeding method and the control tactics are effective in the automatic balancing head for vibration controlling.

  20. Application of automatic tube current modulation on image quality and radiation dose at abdominal CT%自动管电流调制技术对腹部CT图像质量及辐射剂量影响的体模研究

    Institute of Scientific and Technical Information of China (English)

    王倩; 赵心明; 宋俊峰; 郭宁; 朱颖; 刘建新; 綦维维; 武靖; 梁媛

    2013-01-01

    .20 mSv.NI值与图像质量主、客观评价指标及辐射剂量指标间呈高度线性相关(r=0.871~0.982,P值均<0.05).实验组NI =4 ~7组与对照组间SD、CNR差异均无统计学意义(t值分别为-1.63 ~-0.17,0.03 ~1.12,P值均>0.05).实验组NI=4~ 10组与对照组间LCD评分差异均无统计学意义(Z值为-1.637 ~0.000,P值均>0.05).实验组NI =4 ~ 13组与对照组间HCD得分差异均无统计学意义(Z值为-1.423 ~0.000,P值均>0.05).3名医师对LCD、HCD评分的Kappa一致性检验结果分别为0.743、0.795.结论 在腹部CT扫描中应用自动管电流调制技术可确保图像质量,同时降低辐射剂量.%Objective To investigate the effect of automatic tube current modulation (ATCM) on image quality and radiation dose for abdominal CT.Methods An abdomen-equivalent tissue model in the present study was developed,by referring to the CTP515 auxiliary performance testing model made by the internationally recognized Phantom Laboratory,in conjunction with the real data from 68 Chinese male subjects with BMI between 18 to 24 kg/cm2 (subjects with fatty liver,cirrhosis,intraperitoneal huge tumor,ascites or pleural effusion or who were under 18 years old were excluded).Catphan600 performance served as observation object,and simulating adult abdominal CT low and high contrast characteristics to research.Control groups were scanned with CT protocol at fixed 120 kV,450 mA and experimental group were scanned with the same tube voltage and variable current range from 10 to 450 mA (NI value:4 to 20),respectively.CT value was measured by homogeneous area in the center of Catphan600 to verify the phantom for X-ray attenuation of equivalence.CT dose index (CTDIvol),size-specific dose estimates (SSDE),dose length product (DLP),image noise (SD) and contrast to noise ratio (CNR) were recorded and measured.Fifteen mm diameter low-contrast detectability in CTP515 and high-contrast detectability in CTP528 at Catphan600 were

  1. Multifrequency Eddy current testing of heat exchange tubes with a rotating probe

    International Nuclear Information System (INIS)

    Multi-frequency eddy current analyses have been used in France industrially since 1975. In light of the experienced gained during many steam generator inspections, this technique was applied to the examination of sheet and tube heat exchangers featuring tubes in very different materials such as copper, stainless steel and titanium. The principle of multi-frequency Eddy current inspection is first reviewed, using the example of a condenser with nickel alloy tubes (Inconel, Incoloy). This is followed by the description of a specific application of this technique to a condenser with titanium tubes, analyzed with a rotating local probe

  2. Automatic thickness measuring system of zirconium and zircaloy-2 layers of zirconium liner cladding tubes for boiling water reactor

    International Nuclear Information System (INIS)

    An automatic measuring system using ultrasonic method and electromagnetic method has been developed to measure the thickness of zirconium and zircaloy-2 layers. The sophisticated mechanism and the unique signal processing for suppression of several types of error enable high accurate measurement. The standard deviation of the liner thickness measurement is 2.2 μm and that of mother layer measurement is 3.0 μm. This system is very useful to assure the thickness of each layer and to produce high quality zirconium liner cladding tubes. (author)

  3. Expert system for eddy current signal analysis: non destructive testing of steam generator tubings

    International Nuclear Information System (INIS)

    Automatic analysis, by computer, of defect signals in steam generator tubes, based on Eddy current multifrequency technique, is must often inefficient due to pilgrim noise. The first step is to use a method that allows us to eleminate the noise: the adaptative interpolation. Thanks to this method, which ensures reliable data on each channel, the analysis can be realised by taking into account the data corresponding to each basic or mixed channel. By correlating these diverse data, we can class the signals according to two types of defects: single defects (symmetrical), multiple defects (several in the same place). The second step is to use an expert system which allows a reliable diagnosis for whatever family the defect belongs to. According to this classification, analysis is continued and results in the characterization of the defect. The expert system has already been developed with the general purpose application expert system shell SUPER, which is briefly described. The knowledge base (SOCRATE) and the specific tools developed for this application are thoroughly described. The first results obtained with signals corresponding to real defects, that have been recorded in different places, are presented and discussed. The expert system is revealed efficient in all the studied cases, even with signals obtained in very noisy environments

  4. Task-driven tube current modulation and regularization design in computed tomography with penalized-likelihood reconstruction

    Science.gov (United States)

    Gang, G. J.; Siewerdsen, J. H.; Stayman, J. W.

    2016-03-01

    Purpose: This work applies task-driven optimization to design CT tube current modulation and directional regularization in penalized-likelihood (PL) reconstruction. The relative performance of modulation schemes commonly adopted for filtered-backprojection (FBP) reconstruction were also evaluated for PL in comparison. Methods: We adopt a task-driven imaging framework that utilizes a patient-specific anatomical model and information of the imaging task to optimize imaging performance in terms of detectability index (d'). This framework leverages a theoretical model based on implicit function theorem and Fourier approximations to predict local spatial resolution and noise characteristics of PL reconstruction as a function of the imaging parameters to be optimized. Tube current modulation was parameterized as a linear combination of Gaussian basis functions, and regularization was based on the design of (directional) pairwise penalty weights for the 8 in-plane neighboring voxels. Detectability was optimized using a covariance matrix adaptation evolutionary strategy algorithm. Task-driven designs were compared to conventional tube current modulation strategies for a Gaussian detection task in an abdomen phantom. Results: The task-driven design yielded the best performance, improving d' by ~20% over an unmodulated acquisition. Contrary to FBP, PL reconstruction using automatic exposure control and modulation based on minimum variance (in FBP) performed worse than the unmodulated case, decreasing d' by 16% and 9%, respectively. Conclusions: This work shows that conventional tube current modulation schemes suitable for FBP can be suboptimal for PL reconstruction. Thus, the proposed task-driven optimization provides additional opportunities for improved imaging performance and dose reduction beyond that achievable with conventional acquisition and reconstruction.

  5. Evaluation of the use of automatic exposure control and automatic tube potential selection in low-dose cerebrospinal fluid shunt head CT

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, Adam N.; Bagade, Swapnil; Chatterjee, Arindam; Hicks, Brandon; McKinstry, Robert C. [Barnes Jewish Hospital, Mallinckrodt Institute of Radiology, St. Louis, MO (United States); Washington University School of Medicine, St. Louis, MO (United States); Vyhmeister, Ross [Washington University School of Medicine, St. Louis, MO (United States); Ramirez-Giraldo, Juan Carlos [Siemens Healthcare, Malvern, PA (United States)

    2015-03-17

    Cerebrospinal fluid shunts are primarily used for the treatment of hydrocephalus. Shunt complications may necessitate multiple non-contrast head CT scans resulting in potentially high levels of radiation dose starting at an early age. A new head CT protocol using automatic exposure control and automated tube potential selection has been implemented at our institution to reduce radiation exposure. The purpose of this study was to evaluate the reduction in radiation dose achieved by this protocol compared with a protocol with fixed parameters. A retrospective sample of 60 non-contrast head CT scans assessing for cerebrospinal fluid shunt malfunction was identified, 30 of which were performed with each protocol. The radiation doses of the two protocols were compared using the volume CT dose index and dose length product. The diagnostic acceptability and quality of each scan were evaluated by three independent readers. The new protocol lowered the average volume CT dose index from 15.2 to 9.2 mGy representing a 39 % reduction (P < 0.01; 95 % CI 35-44 %) and lowered the dose length product from 259.5 to 151.2 mGy/cm representing a 42 % reduction (P < 0.01; 95 % CI 34-50 %). The new protocol produced diagnostically acceptable scans with comparable image quality to the fixed parameter protocol. A pediatric shunt non-contrast head CT protocol using automatic exposure control and automated tube potential selection reduced patient radiation dose compared with a fixed parameter protocol while producing diagnostic images of comparable quality. (orig.)

  6. Sausage Instabilities on top of Kinking Lengthening Current-Carrying Magnetic Flux Tubes

    Science.gov (United States)

    von der Linden, Jens; You, Setthivoine

    2015-11-01

    Observations indicate that the dynamics of magnetic flux tubes in our cosmos and terrestrial experiments involve fast topological change beyond MHD reconnection. Recent experiments suggest that hierarchies of instabilities coupling disparate plasma scales could be responsible for this fast topological change by accessing two-fluid and kinetic scales. This study will explore the possibility of sausage instabilities developing on top of a kink instability in lengthening current-carrying magnetic flux tubes. Current driven flux tubes evolve over a wide range of aspect ratios k and current to magnetic flux ratios λ . An analytical stability criterion and numerical investigations, based on applying Newcomb's variational approach to idealized magnetic flux tubes with core and skin currents, indicate a dependence of the stability boundaries on current profiles and overlapping kink and sausage unstable regions in the k - λ trajectory of the flux tubes. A triple electrode planar plasma gun (Mochi.LabJet) is designed to generate flux tubes with discrete core and skin currents. Measurements from a fast-framing camera and a high resolution magnetic probe are being assembled into stability maps of the k - λ space of flux tubes. This work was sponsored in part by the US DOE Grant DE-SC0010340.

  7. Design and array signal suggestion of array type pulsed eddy current probe for health monitoring of metal tubes

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Young Kil [Dept. of Electrical Engineering, Kunsan National University, Kunsan (Korea, Republic of)

    2015-10-15

    An array type probe for monitoring metal tubes is proposed in this paper which utilizes peak value and peak time of a pulsed eddy current(PEC) signal. The probe consists of an array of encircling coils along a tube and the outside of coils is shielded by ferrite to prevent source magnetic fields from directly affecting sensor signals since it is the magnetic fields produced by eddy currents that reflect the condition of metal tubes. The positions of both exciter and sensor coils are consecutively moved automatically so that manual scanning is not necessary. At one position of send-receive coils, peak value and peak time are extracted from a sensor PEC signal and these data are accumulated for all positions to form an array type peak value signal and an array type peak time signal. Numerical simulation was performed using the backward difference method in time and the finite element method for spatial analysis. Simulation results showed that peak value increases and the peak appears earlier as the defect depth or length increases. The proposed array signals are shown to be excellent in reflecting the defect location as well as variations of defect depth and length within the array probe.

  8. Automatic method of measuring silicon-controlled-rectifier holding current

    Science.gov (United States)

    Maslowski, E. A.

    1972-01-01

    Development of automated silicon controlled rectifier circuit for measuring minimum anode current required to maintain rectifiers in conducting state is discussed. Components of circuit are described and principles of operation are explained. Illustration of circuit is provided.

  9. Automatic control system for measuring currents produced by ionization chambers

    International Nuclear Information System (INIS)

    Ionization Chambers in current mode operation are usually used in Nuclear Metrology. Activity measurements are quickly performed by Ionization Chambers, with very good precision. For this purpose measurements of very low ionization currents, carried out by high quality instrumentation, are required. Usually, electrometers perform the current integration method under command of signals from an automation system, in order to reduce the measurement uncertainties. Among the measurement systems at the Laboratorio de Metrologia Nuclear (LMN) of IPEN, there are two ionization chamber systems. In the present work, an automation system developed for current integration measurements is described. This automation system is composed by software (graphic interface and control) and an electronic module connected to a microcomputer, by means of a commercial data acquisition card. Several test measurements were performed in order to determine the intrinsic uncertainty, linearity and stability of the system. Using calibrated radioactive solutions, the IG12/A20 chamber calibration factors for 18F and 153Sm were obtained, making possible to determine activities of these radionuclides. (author)

  10. Application of Pulsed Eddy Current for Depth Measurement of Steam Generator's Wear scar tube standard

    International Nuclear Information System (INIS)

    The integrity of stem generator tube in nuclear power plant is the critical problem but the particular area on the stem generator tube could be worn away by inside impurities, fluid flow and vibration from the outside environment. At the present, the inspection of stem generator tube has been performed by using a conventional eddy current testing. Although the conventional eddy current testing is a powerful method to detect flaws of tube in online processing, it is difficult to measure the deep depth differences of the tube. Because eddy current density has changed its magnitude with distance from the surface. Whereas, the pulsed eddy current technique has been widely employed for deep depth inspection of structures such as plate, tubes. For more effective inspection, the pulsed eddy current system is enveloped to control a depth difference and submitted the multi-pointing method to select a criteria which could be obtained depth differences by the period of resistivity on the pulsed eddy current transient signals. In this paper, we used the pulsed eddy current technique to improve the capability of depth difference measurement and studied multi-pointing method to evaluate the thickness with variation of resistivity.

  11. Study on focusing characteristic of acceleration tube in high current implanter

    International Nuclear Information System (INIS)

    The accelerating tube is one of the most important parts in high current implanter which provides the desired energy and focusing for ion beam. The factors affecting focus characteristic in high current implanter with three gap acceleration tube are discussed. Focusing degrees of different energy ion beam are computed, and the electric field required to prevent beam expansion due to space charge effect are analyzed. The beam envelope inside the three acceleration gap shows a decrease of the beam radius with the increase of the accelerating voltage ratio up to the optimal value. Beyond this optimal value the beam lines make a crossover with the axis of the accelerating tube

  12. Data analysis algorithms for flaw sizing based on eddy current rotating probe examination of steam generator tubes

    International Nuclear Information System (INIS)

    Computer-aided data analysis tools can help improve the efficiency and reliability of flaw sizing based on nondestructive examination data. They can further help produce more consistent results, which is important for both in-service inspection applications and for engineering assessments associated with steam generator tube integrity. Results of recent investigations at Argonne on the development of various algorithms for sizing of flaws in steam generator tubes based on eddy current rotating probe data are presented. The research was carried out as part of the activities under the International Steam Generator Tube Integrity Program (ISG-TIP) sponsored by the U.S. Nuclear Regulatory Commission. A computer-aided data analysis tool has been developed for off-line processing of eddy current inspection data. The main objectives of the work have been to a) allow all data processing stages to be performed under the same user interface, b) simplify modification and testing of signal processing and data analysis scripts, and c) allow independent evaluation of viable flaw sizing algorithms. The focus of most recent studies at Argonne has been on the processing of data acquired with the +Point probe, which is one of the more widely used eddy current rotating probes for steam generator tube examinations in the U.S. The probe employs a directional surface riding differential coil, which helps reduce the influence of tubing artifacts and in turn helps improve the signal-to-noise ratio. Various algorithms developed under the MATLAB environment for the conversion, segmentation, calibration, and analysis of data have been consolidated within a single user interface. Data acquired with a number of standard eddy current test equipment are automatically recognized and converted to a standard format for further processing. Because of its modular structure, the graphical user interface allows user-developed routines to be easily incorporated, modified, and tested independent of the

  13. Data analysis algorithms for flaw sizing based on eddy current rotating probe examination of steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Bakhtiari, S.; Elmer, T.W. [Argonne National Laboratory, Nuclear Energy Division, Lemont, Illinois (United States)

    2009-07-01

    Computer-aided data analysis tools can help improve the efficiency and reliability of flaw sizing based on nondestructive examination data. They can further help produce more consistent results, which is important for both in-service inspection applications and for engineering assessments associated with steam generator tube integrity. Results of recent investigations at Argonne on the development of various algorithms for sizing of flaws in steam generator tubes based on eddy current rotating probe data are presented. The research was carried out as part of the activities under the International Steam Generator Tube Integrity Program (ISG-TIP) sponsored by the U.S. Nuclear Regulatory Commission. A computer-aided data analysis tool has been developed for off-line processing of eddy current inspection data. The main objectives of the work have been to a) allow all data processing stages to be performed under the same user interface, b) simplify modification and testing of signal processing and data analysis scripts, and c) allow independent evaluation of viable flaw sizing algorithms. The focus of most recent studies at Argonne has been on the processing of data acquired with the +Point probe, which is one of the more widely used eddy current rotating probes for steam generator tube examinations in the U.S. The probe employs a directional surface riding differential coil, which helps reduce the influence of tubing artifacts and in turn helps improve the signal-to-noise ratio. Various algorithms developed under the MATLAB environment for the conversion, segmentation, calibration, and analysis of data have been consolidated within a single user interface. Data acquired with a number of standard eddy current test equipment are automatically recognized and converted to a standard format for further processing. Because of its modular structure, the graphical user interface allows user-developed routines to be easily incorporated, modified, and tested independent of the

  14. Analysis method of deposit on steam generator tubes using eddy current

    International Nuclear Information System (INIS)

    The steam generator tubes in operating nuclear power plants have an important problem during their operation time, an accumulation of corrosion products. Such corrosion products form from the secondary side of the plant system, such as carbon steel pipelines, heat exchange shell, and turbine. The accumulation position of corrosion product is mainly on the top of the tubesheet, the tube support structures of the steam generator. It is extinguished as sludge, and as a deposit of the corrosion product. The volume increase and hardening of the sludge eventually cause the tube deformation, and a blockage of the coolant flow of the tube supports. A deposit outside the tube results in reducing the heat transfer through the tube wall, and distorts the eddy current signals during an in service inspection. For the management of steam generator tubes from the problems mentioned previously, several methods were performed. The corrosion products could be reduced by chemical cleaning and sludge lancing. The monitoring of the quantity of sludge and deposit is very important data in the management of steam generator tubes. An eddy current testing (ECT) method is very useful to detect flaws and defects in the steam generator (SG) tubes of nuclear power plants (NPPs) during an in service inspection. Recently, it was reported that deposit loading can be measured using eddy current test data, especially of a bobbin probe. For a precision measurement using a non destructive method, a calibration technique is required using the simulated deposit and signal characteristics from the deposit standard. In this study, a personal computer based device was developed for an analysis of ECT signals. The soft wave program can convert the commercial eddy current data and measure the deposit amount from the calibration data

  15. Research on automatic non-destructive testing system of oil coiled tubing

    Science.gov (United States)

    Guo, Rong; Qiu, Wenbin; Wang, Yuhui; Ren, Jianguang

    2010-10-01

    A method using ultrasonic devices for on-line measurement of oil coiled tubing was proposed. The principle of ultrasonic testing was analyzed. Then, the structure of the system consisting of mechanical system, coupling system, measuring system, control system and system software was determinated. Based on the analysis of technology requirement, measuring technique in which the coiled tubing did not rotate and the probe was static was chosen. The ultrasonic testing probes were triggered in turn. After signal sampling, digital filtering and A / D conversion signal processing, the received echo signals were sent to computer. Through analyzing and accounting, the test results were obtained. Based on VC++.net, A-type ultrasonic and C-type ultrasonic display software and the inspection data processing software were developed. Using Windows programming technology, the software structure and function library were totally open. Therefore, secondary development can be carried out conveniently. Based on the experimental studies, coiled tubing's ultrasonic testing system is developed. The testing results show that the system has specific advantages such as high-adaptation, highefficiency, high- stability, high reliability and can meet the need of the users. The ultrasonic testing technologies proposed in this paper can be applied extensively to other tubes.

  16. Current Status on the Development of a Double Wall Tube Steam Generator

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Ho Yun; Choi, Byoung Hae; Kim, Jong Man; Kim, Byung Ho

    2007-12-15

    A fast reactor, which uses sodium as a coolant, has a lot of merits as a next generation nuclear reactor. However, the possibility of a sodium-water reaction occurrence hinders the commercialization of this reactor. As one way to improve the reliability of a steam generator, a double-wall tube steam generator is being developed in GEN-4 program. In this report, the current state of the technical developments for a double-wall tube steam generator are reviewed and a future plan for the development of a double-wall tube steam generator is established. The current focuses of this research are an improvement of the heat transfer capability for a double-wall tube and the development of a proper leak detection method for the failure of a double-wall tube during a reactor operation. The ideal goal is an on-line leak detection of a double wall tube to prevent the sodium-water reaction. However, such a method is not developed as yet. An alternative method is being used to improve the reliability of a steam generator by performing a non-destructive test of a double wall tube during the refueling period of a reactor. In this method a straight double wall tube is employed to perform this test easily, but has a difficulty regarding an absorption of a thermal expansion of the used materials. If an on-line leak detection method is developed, the demerits of a straight double-wall tube are avoided by using a helical type double-wall tube, and the probability of a sodium-water reaction can be reduced to a level less than the design-based accident.

  17. Vacuum current and magnetic field induced by an impenetrable flux tube. Dirichlet problem

    CERN Document Server

    Gorkavenko, Volodymyr M

    2015-01-01

    We consider the vacuum polarization effects created by a finite radius magnetic-flux-carrying tube that is impenetrable for quantum matter. The vacuum polarization depends on the choice of a boundary condition at the edge of the tube. We impose a perfectly reflecting (Dirichlet) boundary condition at the edge of the tube on the charged massive scalar matter field which is quantized outside the tube. We find that a current is induced in the vacuum of the quantized scalar field and it circulates around the tube. As a consequence of the Maxwell equation, a magnetic field strength is also induced in the vacuum and is directed along the tube. We restrict our consideration to a plane case. The behavior of the current and the field strength is comprehensively analyzed. In contrast to the model of singular magnetic filament, magnetic field strength is finite at the edge of the string. Induced vacuum effects strongly depend on the tube radius $r_0$. They are quite negligible at $mr_0 > 1$, whereas it becomes noticeabl...

  18. Radiation dose calculations for CT scans with tube current modulation using the approach to equilibrium function

    International Nuclear Information System (INIS)

    Purpose: The approach to equilibrium function has been used previously to calculate the radiation dose to a shift-invariant medium undergoing CT scans with constant tube current [Li, Zhang, and Liu, Med. Phys. 39, 5347–5352 (2012)]. The authors have adapted this method to CT scans with tube current modulation (TCM). Methods: For a scan with variable tube current, the scan range was divided into multiple subscan ranges, each with a nearly constant tube current. Then the dose calculation algorithm presented previously was applied. For a clinical CT scan series that presented tube current per slice, the authors adopted an efficient approach that computed the longitudinal dose distribution for one scan length equal to the slice thickness, which center was at z = 0. The cumulative dose at a specific point was a summation of the contributions from all slices and the overscan. Results: The dose calculations performed for a total of four constant and variable tube current distributions agreed with the published results of Dixon and Boone [Med. Phys. 40, 111920 (14pp.) (2013)]. For an abdomen/pelvis scan of an anthropomorphic phantom (model ATOM 701-B, CIRS, Inc., VA) on a GE Lightspeed Pro 16 scanner with 120 kV, N × T = 20 mm, pitch = 1.375, z axis current modulation (auto mA), and angular current modulation (smart mA), dose measurements were performed using two lines of optically stimulated luminescence dosimeters, one of which was placed near the phantom center and the other on the surface. Dose calculations were performed on the central and peripheral axes of a cylinder containing water, whose cross-sectional mass was about equal to that of the ATOM phantom in its abdominal region, and the results agreed with the measurements within 28.4%. Conclusions: The described method provides an effective approach that takes into account subject size, scan length, and constant or variable tube current to evaluate CT dose to a shift-invariant medium. For a clinical CT scan

  19. Automatic ultrasonic inspection system for wear determination in calandria tubes of Embalse Nuclear Power Plant

    Science.gov (United States)

    Katchadjian, Pablo; Desimone, Carlos; Garcia, Alejandro; Antonaccio, Carlos; Schroeter, Fernando; Molina, Héctor

    2015-03-01

    Embalse Nuclear Power Plant (CNE) (CANDU design) is reaching its end of life and due to elapsed operating time the problem of deformation by accelerated creep occurs in the pressure tubes (PT), leading to a possible contact between calandria tubes (CT), concentric to the PT, and some Liquid Injection Shutdown System (LISS) nozzles that pass underneath them. With determination of CT wear, after the predicted contact occurs, the wear rate of the TC could be determined and thus take less conservative measures over the remaining life of the component. This paper presents the development of an ultrasonic technique for measuring wear in CT, with nominal thickness of 1.34 mm. Because the only access is through the interior of PT, to perform this measurement it is necessary to pass through three different interfaces.

  20. Automatic ultrasonic inspection system for wear determination in calandria tubes of Embalse Nuclear Power Plant

    International Nuclear Information System (INIS)

    Embalse Nuclear Power Plant (CNE) (CANDU design) is reaching its end of life and due to elapsed operating time the problem of deformation by accelerated creep occurs in the pressure tubes (PT), leading to a possible contact between calandria tubes (CT), concentric to the PT, and some Liquid Injection Shutdown System (LISS) nozzles that pass underneath them. With determination of CT wear, after the predicted contact occurs, the wear rate of the TC could be determined and thus take less conservative measures over the remaining life of the component. This paper presents the development of an ultrasonic technique for measuring wear in CT, with nominal thickness of 1.34 mm. Because the only access is through the interior of PT, to perform this measurement it is necessary to pass through three different interfaces

  1. Automatic ultrasonic inspection system for wear determination in calandria tubes of Embalse Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Katchadjian, Pablo, E-mail: katcha@cnea.gov.ar; Desimone, Carlos, E-mail: katcha@cnea.gov.ar; Garcia, Alejandro, E-mail: katcha@cnea.gov.ar [Comisión Nacional de Energía Atómica, Depto. ENDE - INEND, Av. Gral. Paz 1499, Buenos Aires (Argentina); Antonaccio, Carlos; Schroeter, Fernando; Molina, Héctor [Nucleoeléctrica Argentina-SA, Arribeños 3619, Buenos Aires (Argentina)

    2015-03-31

    Embalse Nuclear Power Plant (CNE) (CANDU design) is reaching its end of life and due to elapsed operating time the problem of deformation by accelerated creep occurs in the pressure tubes (PT), leading to a possible contact between calandria tubes (CT), concentric to the PT, and some Liquid Injection Shutdown System (LISS) nozzles that pass underneath them. With determination of CT wear, after the predicted contact occurs, the wear rate of the TC could be determined and thus take less conservative measures over the remaining life of the component. This paper presents the development of an ultrasonic technique for measuring wear in CT, with nominal thickness of 1.34 mm. Because the only access is through the interior of PT, to perform this measurement it is necessary to pass through three different interfaces.

  2. Multi-element eddy current probe. For inspecting steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Savin, E.; Sartre, B. [FRAMATOME, 92 - Paris-La-Defense (France); Placko, D.; Premel, D. [Ecole Nationale Superieure de Cachan, 94 (France)

    2000-10-01

    Framatome and the Ecole Normale Superieure de Cachan are developing a multi-element eddy current probe for inspecting steam generator tubes of 900 MWe PWR reactors. The device is intended to replace much slower rotating probes. Using its measurements, the conductivity image of any point in the tube can be reconstructed, thanks to a numerical, thanks to a numerical model, thus allowing diagnosis. The first trial results on mockups seem already competitive with those obtained using a rotary probe. (authors)

  3. Correlation between General Corrosion Behavior and Eddy Current Noise of Alloy 690 Steam Generator Tube

    Energy Technology Data Exchange (ETDEWEB)

    Hur, Do Haeng; Choi, Myung Sik; Lee, Deok Hyun; Shim, Hee-Sang [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    Nickel and its oxides are released from the surface of steam generator tubes into the primary water. Released nickel and cobalt is activated to Co-58 and Co-60 in the reactor core by a neutron flux, respectively. These activated corrosion products are the main source of high radiation fields and occupational radiation exposure. In addition, some of the corrosion products redeposit on the fuel cladding, hinder the heat transfer, increase the corrosion rate of the fuel cladding, and finally induce an axial offset anomaly. This phenomenon can decrease core shutdown margin, and thus lead to a down-rating of a plant. Recently, many researchers have reported that the surface states of Alloy 690 tubes affect the corrosion product formation and its release in simulated primary water environments. Meanwhile, the surface states of steam generator tubes affect the noise level of eddy current testing. Noise signals arising from the tubes degrade the probability of detection and sizing accuracy of the defects. The corrosion behavior was closely correlated to the tube noise measured using a rotating probe, while it was not related to the noise measured using a bobbin probe. It is suggested that the tube noise value measured using a rotating pancake coil probe can be a decisive measure to estimate the corrosion behavior of tubing.

  4. Nondestructive Examination of Ferromagnetic Tube Using Magnetic Saturation Eddy Current Technique

    International Nuclear Information System (INIS)

    The tubes in heat exchanger are typically made from copper alloy, stainless steel, carbon steel, titanium alloy material. Type-439 ferritic stainless steel is ferromagnetic material, and furnish higher heat transfer rates than austenitic stainless steels and higher resistance to corrosion-induced flaws. Ferritic stainless steel can typically be found in low-pressure(LP) feedwater heaters and moisture separator reheaters(MSRs). LP feedwater heaters generally utilize thin wall type-439 stainless steel tubing, whereas MSRs typically employ a heavier wall tubing with integral fins. Service-induced damage can occur on the OD(outside diameter) surface of type-439 ferritic stainless steel tubing which is employed for MSRs tubing, and the most typical damage mechanism is vibration-induced tube-to-TSP(tube support plate) wear and fatigue cracking. The wear has been reported that occurs mainly on the OD surface. Accordingly, in this study, we have evaluated the flaw sizing capability of magnetic saturation eddy current technique using magnetic saturation probe and flawed specimen

  5. Eddy Currents Inspection of CANDU Steam Generators' Tubes using Zetec's ZR-1 Robot. Experience in Romania

    International Nuclear Information System (INIS)

    This is a PowerPoint presentation on behalf of COMPCONTROL ING, a Romanian private company established in 1997 the main services of which are enlisted. It is stressed that the most suitable type of inspection in terms of safety and reliability for the steam generator tubes is eddy current (EC) method. The advantages of EC testing include the following: - Extremely fast; - Accurate in detection and sizing of discontinuities; - Very good method for baseline screening; - Very high detection sensitivity to physical-chemical variations of the test specimen; - Easy setup and application for automated inspection; - Portable equipment designing; - Use of multiple channels and multi-frequencies for a better screening of signals and efficiency; - High capability to store the data for future review and comparison (using data history to evaluate the rate of degradation and life assessment studies). Between 2003 and 2005 ECT was applied to Cernavoda NPP U1 SGs as follows: - in 2003, SG-4; - in 2004, SG-2; - in 2005, SG-1; - in 2005, SG-3; - in 2005, SG-4. The purpose of inspection with eddy currents of SGs tubes was: - Detection, sizing and evaluation of possible degradations of the tubes and at the interface tube/support structures (tubesheet, tube support plates and baffles); - Completion of the baseline data for future review and comparison. The software used for acquisition and analysis of eddy current data and for inspection management were: - ZETEC Eddynet-R Zetec Acquisition Control-ZAC; - ZETEC Eddynet-R Data Analysis (bobbin and MRPC); - ZETEC Eddynet-R Data Management. The equipment ZR-1 is described and its advantages as well. Advantages of the automated scanning system are highlighted as follows: - Repeatability; - High resolution mapping; - Accurate indexing; - Minimize changes in lift-off resulting from probe wobble, eccentricity of the tube and surface irregularities; - 3-part design makes each component lighter and more compact for easier, faster installation

  6. Equivalency assessment for an eddy current system used for steam generator tubing inspection

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Chan Hee; Lee, Tae Hun; Yoo, Hyun Ju; Moon, Gyoon Young [Korea Hydro and Nuclear Power Company Ltd., Central Research Institute, Daejeon (Korea, Republic of)

    2015-08-15

    Eddy current testing is widely used for inspecting steam generator tubing in nuclear power plants (NPPs). The inspection technique for steam generator tubing in NPPs should be qualified in accordance with examination guidelines. When the components of a qualified system such as eddy current tester, probe, and data analysis program, are changed, the equivalency of the modified system to the originally qualified system must be verified. The eddy current tester is the most important part of an eddy current testing system because it excites and transmits alternating currents to the probe, receives coil impedance of the probe and generates signals for anomalies. The Korea Hydro and Nuclear Power Co., Ltd. (KHNP) developed an eddy current testing system with an eddy current tester and data acquisition-analysis program for inspecting the steam generator tubing in NPPs; this system can be used for an array probe and as a bobbin and rotating probes. The equivalency assessment for the currently developed system was carried out, and we describe the results in this paper.

  7. Ultrasound testing of the penetration of automatic welds of tubes on plates with using electron beams

    International Nuclear Information System (INIS)

    This control technique was developed within the scope of a D.G.R.S.T. study on electron beam welding of tubes to exchanger plates with a portable gun. The device developed is easy to use and enables the control to be carried out according to various techniques with good accuracy: used for acceptance tests merely for testing that a penetration to specification is reached and by working by 'hit and miss', it permits high work rates; used as a quality control system, it enables recordings to be made which accurately record the shape of the weld bead root, the penetration depth (and any possible weld compactness faults). The work rate is then reduced. Of course, the combined use of both techniques is possible, even advisable in some cases. For example, it is possible to imagine a total control by the first technique and an additional exploration by the second one. The exploration can then be to a percentage fixed by agreement or better, form a supplementary examination orientated according to the results obtained during the short examination

  8. Feasibility of low-concentration iodinated contrast medium with lower-tube-voltage dual-source CT aortography using iterative reconstruction: comparison with automatic exposure control CT aortography.

    Science.gov (United States)

    Shin, Hee Jeong; Kim, Song Soo; Lee, Jae-Hwan; Park, Jae-Hyeong; Jeong, Jin-Ok; Jin, Seon Ah; Shin, Byung Seok; Shin, Kyung-Sook; Ahn, Moonsang

    2016-06-01

    To evaluate the feasibility of low-concentration contrast medium (CM) for vascular enhancement, image quality, and radiation dose on computed tomography aortography (CTA) using a combined low-tube-voltage and iterative reconstruction (IR) technique. Ninety subjects underwent dual-source CT (DSCT) operating in dual-source, high-pitch mode. DSCT scans were performed using both high-concentration CM (Group A, n = 50; Iomeprol 400) and low-concentration CM (Group B, n = 40; Iodixanol 270). Group A was scanned using a reference tube potential of 120 kVp and 120 reference mAs under automatic exposure control with IR. Group B was scanned using low-tube-voltage (80 or 100 kVp if body mass index ≥25 kg/m(2)) at a fixed current of 150 mAs, along with IR. Images of the two groups were compared regarding attenuation, image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), iodine load, and radiation dose in various locations of the CTA. In comparison between Group A and Group B, the average mean attenuation (454.73 ± 86.66 vs. 515.96 ± 101.55 HU), SNR (25.28 ± 4.34 vs. 31.29 ± 4.58), and CNR (21.83 ± 4.20 vs. 27.55 ± 4.81) on CTA in Group B showed significantly greater values and significantly lower image noise values (18.76 ± 2.19 vs. 17.48 ± 3.34) than those in Group A (all Ps < 0.05). Homogeneous contrast enhancement from the ascending thoracic aorta to the infrarenal abdominal aorta was significantly superior in Group B (P < 0.05). Low-concentration CM and a low-tube-voltage combination technique using IR is a feasible method, showing sufficient contrast enhancement and image quality. PMID:26621755

  9. Analysis of pulsed eddy current data using regression models for steam generator tube support structure inspection

    Science.gov (United States)

    Buck, J. A.; Underhill, P. R.; Morelli, J.; Krause, T. W.

    2016-02-01

    Nuclear steam generators (SGs) are a critical component for ensuring safe and efficient operation of a reactor. Life management strategies are implemented in which SG tubes are regularly inspected by conventional eddy current testing (ECT) and ultrasonic testing (UT) technologies to size flaws, and safe operating life of SGs is predicted based on growth models. ECT, the more commonly used technique, due to the rapidity with which full SG tube wall inspection can be performed, is challenged when inspecting ferromagnetic support structure materials in the presence of magnetite sludge and multiple overlapping degradation modes. In this work, an emerging inspection method, pulsed eddy current (PEC), is being investigated to address some of these particular inspection conditions. Time-domain signals were collected by an 8 coil array PEC probe in which ferromagnetic drilled support hole diameter, depth of rectangular tube frets and 2D tube off-centering were varied. Data sets were analyzed with a modified principal components analysis (MPCA) to extract dominant signal features. Multiple linear regression models were applied to MPCA scores to size hole diameter as well as size rectangular outer diameter tube frets. Models were improved through exploratory factor analysis, which was applied to MPCA scores to refine selection for regression models inputs by removing nonessential information.

  10. Examination of coiled steam-generator tubes by the multifrequency eddy current method

    International Nuclear Information System (INIS)

    If a generator tube in a fast-neutron breeder reactor is perforated, there could follow a violent water-sodium reaction which may damage the tubes in the vicinity. To reduce this risk it is necessary to detect any wastage of tube thickness and assess its severity. In the French fast-reactor design each of the tubes to be examined is in the form of a coil with an entry loop at the top and an expansion loop at its lower extremity. The length of the whole, which is composed of several sections assembled by means of butt welds, is about 100m. The coils are wound round an inert core and held in place by clips and toothed support devices. There are two main problems, (a) how to insert a probe into a coiled tube; (b) how to make an effective measurement by the eddy current technique in view of the many disturbing factors present. The first is overcome by using the Discault apparatus described here. The second can be overcome by eddy currents analysis at different frequencies and then using different combinations of the signals to reduce the number of disturbing factors. (U.K.)

  11. Enhancement of the Remote Field Eddy Current Testing Performed from Outside of a Magnetic Tube

    Directory of Open Access Journals (Sweden)

    Tomas Marek

    2006-01-01

    Full Text Available The paper deals with design of remote field eddy current probe for non-destructive testing dedicated for inspection of ferromagnetic tubular material from outside. The remote field effect inside the tube wall is achieved by the medium of a magnetic shield covering the probe. Results of numeric simulations made for verification of probe characteristics confirmed the effectiveness of probe design.

  12. Combined leakage flux and eddy current examination system for the inspection of steel tubes

    International Nuclear Information System (INIS)

    A combination of flux leakage and eddy current units ultrasonic wall thickness and optical diameter gauges leads to an economic and reliable system. The solution of problems related to the calibration, signal evaluation and condition monitoring of multi-channel systems is found in computer-supported systems including the digital control of mechanical driving devices. The use of a computerized central controller allows rather high comfort in evaluation and signal processing and presentation. This solution applied to a special class of tubing shows us the way to go further in the field of conventional 4-function oil field tube inspection systems. (orig./RW)

  13. Particular treatments in Eddy current technique. Application to the control of corrugated tubes

    International Nuclear Information System (INIS)

    When the testing of a given product shows that, owing to a particular shape of this product or to its environment, disturbing effects can hide the presence of harmful defects, use must be made of testing artifices or particular treatments enabling an efficient examination to be made. On this score, many eddy current problems are solved by means of the following processes: - use of specific sensors adapted to the geometry of the product, - spectral analysis of the analog results of analyses, - combination of the results of analyses obtained simultaneously at different frequencies (multifrequency techniques). An example of an application is given for corrugated tubes achieved by hollow and helical milling of smooth tubes

  14. Current-driven vortex domain wall motion in wire-tube nanostructures

    Science.gov (United States)

    Espejo, A. P.; Vidal-Silva, N.; López-López, J. A.; Goerlitz, D.; Nielsch, K.; Escrig, J.

    2015-03-01

    We have investigated the current-driven domain wall motion in nanostructures comprised of a pair of nanotube and nanowire segments. Under certain values of external magnetic fields, it is possible to pin a vortex domain wall in the transition zone between the wire and tube segments. We explored the behavior of this domain wall under the action of an electron flow applied in the opposite direction to the magnetic field. Thus, for a fixed magnetic field, it is possible to release a domain wall pinned simply by increasing the intensity of the current density, or conversely, for a fixed current density, it is possible to release the domain wall simply decreasing the magnetic external field. When the domain wall remains pinned due to the competition between the current density and the magnetic external field, it exhibits a oscillation frequency close to 8 GHz. The amplitude of the oscillations increases with the current density and decreases over time. On the other hand, when the domain wall is released and propagated through the tube segment, this shows the standard separation between a steady and a precessional regime. The ability to pin and release a domain wall by varying the geometric parameters, the current density, or the magnetic field transforms these wire-tube nanostructures in an interesting alternative as an on/off switch nano-transistor.

  15. Current-driven vortex domain wall motion in wire-tube nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Espejo, A. P. [Departamento de Física, Universidad de Santiago de Chile (USACH), Av. Ecuador 3493, 9170124 Santiago (Chile); Institute of Nanostructure and Solid State Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg (Germany); Vidal-Silva, N. [Departamento de Física, Universidad de Santiago de Chile (USACH), Av. Ecuador 3493, 9170124 Santiago (Chile); López-López, J. A. [Departamento de Física, Universidad Técnica Federico Santa María, Av. España 1680, Valparaíso (Chile); Goerlitz, D.; Nielsch, K. [Institute of Nanostructure and Solid State Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg (Germany); Escrig, J. [Departamento de Física, Universidad de Santiago de Chile (USACH), Av. Ecuador 3493, 9170124 Santiago (Chile); Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Av. Ecuador 3493, 9170124 Santiago (Chile)

    2015-03-30

    We have investigated the current-driven domain wall motion in nanostructures comprised of a pair of nanotube and nanowire segments. Under certain values of external magnetic fields, it is possible to pin a vortex domain wall in the transition zone between the wire and tube segments. We explored the behavior of this domain wall under the action of an electron flow applied in the opposite direction to the magnetic field. Thus, for a fixed magnetic field, it is possible to release a domain wall pinned simply by increasing the intensity of the current density, or conversely, for a fixed current density, it is possible to release the domain wall simply decreasing the magnetic external field. When the domain wall remains pinned due to the competition between the current density and the magnetic external field, it exhibits a oscillation frequency close to 8 GHz. The amplitude of the oscillations increases with the current density and decreases over time. On the other hand, when the domain wall is released and propagated through the tube segment, this shows the standard separation between a steady and a precessional regime. The ability to pin and release a domain wall by varying the geometric parameters, the current density, or the magnetic field transforms these wire-tube nanostructures in an interesting alternative as an on/off switch nano-transistor.

  16. Transmit-receive eddy current probes for circumferential cracks in heat exchanger tubes

    International Nuclear Information System (INIS)

    Conventional eddy current bobbin probes are known to be ineffectual in detecting circumferential cracks in tubing. Multi-pancake and/or rotating pancake probes are required to detect circumferential cracks. It has recently been demonstrated in CANDU steam generator tubes, with deformation, ferromagnetic deposits, and copper deposits, that multi-channel probes with transmit-receive (T/R) coils are superior to those using surface impedance coils. Unlike rotating probes, the design of a new probe denoted as C3 permits fast, single-scan inspection of a full-length tube at inspection speeds comparable to conventional bobbin probes. Since 1992, the probe has been used routinely for steam generator in-service inspection at 4 CANDU plants. Defective tubes have been plugged and the units returned to service, and they continue to operate without leaks. This paper describes the basic features of T/R surface probes. Two-dimensional voltage diagrams showing computer-derived probe response to frequency, lift-off, carbon steel supports, magnetite deposits and copper deposits are presented and compared with corresponding signals from impedance coils. Theoretical and experimental results show that T/R probes are able to detect defects in the presence of variable lift-off (due to tube-wall deformation) with ten times the signal-to-noise ratio as that exhibited by comparable pancake-type impedance probes. In addition, T/R probes are less sensitive to magnetite deposits, and possess good phase discrimination to internal defects

  17. Phenomenological modeling of eddy current signals with a view to characterizing steam generator tube flaws

    International Nuclear Information System (INIS)

    This work deals with the eddy current non-destructive test ing. Its long-term goal is to design an 'inverse model' for evaluating the geometry an d the dimensions of steam generator tube flaws from eddy current signals. The approach we adopted requires the preliminary knowledge of a 'forward model' that estimates the eddy current signal knowing the geometry and the dimensions of the flaws. A quasi-exhaustive study of the existing forward models showed their inadequacy to solve the inverse problem. Hence, we proposed to build a general forward model, appropriate to the inversion. Using a parametric approach, this model is phenomenological, i.e. it is based on observations made from results of a finite element code. For each position of the coil, the proposed forward model fist discretized the eddy current distribution into 'tubes of current'. A parametric description of the shape of these tubes is given according the system constituted of the coil and the tubes of current as a 'multi-transformer', their current signal, can then be deduced. The model was validated in the case of an axisymmetric configuration. Comparisons with both analytical and numerical models showed very good agreements. Then, the proposed model was applied to a three-dimensional configuration. Comparisons with experimental results are sufficiently conclusive to validate the approach to the construction of the phenomenological model. However, before envisaging the inverse problem, the computation time, still too long, ought to be reduced and the parametric description needs to be generalized to other three-dimensional configurations. (author)

  18. Transmit-receive eddy current probes for defect detection and sizing in steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Obrutsky, L.S.; Cecco, V.S.; Sullivan, S.P. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    1997-02-01

    Inspection of steam generator tubes in aging Nuclear Generating Stations is increasingly important. Defect detection and sizing, especially in defect prone areas such as the tubesheet, support plates and U-bend regions, are required to assess the fitness-for-service of the steam generators. Information about defect morphology is required to address operational integrity issues, i.e., risk of tube rupture, number of tubes at risk, consequential leakage. A major challenge continues to be the detection and sizing of circumferential cracks. Utilities around the world have experienced this type of tube failure. Conventional in-service inspection, performed with eddy current bobbin probes, is ineffectual in detecting circumferential cracks in tubing. It has been demonstrated in CANDU steam generators, with deformation, magnetite and copper deposits that multi-channel probes with transmit-receive eddy current coils are superior to those using surface impedance coils. Transmit-receive probes have strong directional properties, permitting probe optimization according to crack orientation. They are less sensitive to lift-off noise and magnetite deposits and possess good discrimination to internal defects. A single pass C3 array transmit-receive probe developed by AECL can detect and size circumferential stress corrosion cracks as shallow as 40% through-wall. Since its first trial in 1992, it has been used routinely for steam generator in-service inspection of four CANDU plants, preventing unscheduled shutdowns due to leaking steam generator tubes. More recently, a need has surfaced for simultaneous detection of both circumferential and axial cracks. The C5 probe was designed to address this concern. It combines transmit-receive array probe technology for equal sensitivity to axial and circumferential cracks with a bobbin probe for historical reference. This paper will discuss the operating principles of transmit-receive probes, along with inspection results.

  19. Transmit-receive eddy current probes for defect detection and sizing in steam generator tubes

    International Nuclear Information System (INIS)

    Inspection of steam generator tubes in aging Nuclear Generating Stations is increasingly important. Defect detection and sizing, especially in defect prone areas such as the tubesheet, support plates and U-bend regions, are required to assess the fitness-for-service of the steam generators. Information about defect morphology is required to address operational integrity issues, i.e., risk of tube rupture, number of tubes at risk, consequential leakage. A major challenge continues to be the detection and sizing of circumferential cracks. Utilities around the world have experienced this type of tube failure. Conventional in-service inspection, performed with eddy current bobbin probes, is ineffectual in detecting circumferential cracks in tubing. It has been demonstrated in CANDU steam generators, with deformation, magnetite and copper deposits that multi-channel probes with transmit-receive eddy current coils are superior to those using surface impedance coils. Transmit-receive probes have strong directional properties, permitting probe optimization according to crack orientation. They are less sensitive to lift-off noise and magnetite deposits and possess good discrimination to internal defects. A single pass C3 array transmit-receive probe developed by AECL can detect and size circumferential stress corrosion cracks as shallow as 40% through-wall. Since its first trial in 1992, it has been used routinely for steam generator in-service inspection of four CANDU plants, preventing unscheduled shutdowns due to leaking steam generator tubes. More recently, a need has surfaced for simultaneous detection of both circumferential and axial cracks. The C5 probe was designed to address this concern. It combines transmit-receive array probe technology for equal sensitivity to axial and circumferential cracks with a bobbin probe for historical reference. This paper will discuss the operating principles of transmit-receive probes, along with inspection results

  20. Research on automatic current sharing control methods for control power supply

    Directory of Open Access Journals (Sweden)

    Dai Xian Bin

    2016-01-01

    Full Text Available High-power switching devices in control power supply have different saturated forward voltage drops and the inconsistency of turning on/off times and they lead to the inconsistency in the external characteristics of the inverter modules in parallel operation. Modules with good performance in external characteristics undertake more currents and lead to overloading status and modules with bad performance in external characteristics stay in light-loading status, which increases the thermal stress of module undertaking more currents and influences the service life of high-power switching devices. Based on the simulation analysis of the small-signal module using control power supply automatic current sharing method, it is able to find out the characteristics of current-sharing loop control, namely, slow response speed of the current-sharing loop, which is beneficial for improving the stability of the entire control power supply system.

  1. Eddy current monitoring of fatigue crack growth in Zr-2.5% Nb pressure tube

    Science.gov (United States)

    Krause, T. W.; Martin, A. E.; Sheppard, R. R.; Schankula, J. J.

    2000-05-01

    Zr-2.5% wt. Nb pressure tubes (PTs) form the core of the heat transport system in CANDU nuclear reactors. These 6 m long, 100 mm diameter tubes are operated at elevated temperatures (nominally 300 °C) and at pressures that produce hoop stresses that are 25% of the ultimate tensile strength of the PT (120 Mpa). Therefore, detection and characterization of flaws in these components becomes crucial for their continued pressure retaining integrity. If a flaw is detected, however, the cost of PT replacement is expensive. Periodic in-service inspection of a flaw that demonstrates no change in flaw characteristics can be used to allow a pressure tube to remain in-service. This requires confidence in the accuracy and reliability of methods used to inter flaw characteristics. Such confidence can only be developed by comparing nondestructive predictions with results from destructive examinations. In this work, eddy current testing was used to monitor the progressive stages of a fatigue crack, grown through pressure cycling from a notch on the inner surface of a PT. Results from a differential lift-off compensated eddy current probe were used to produce sizing estimates of the crack grown between 35% (base of notch) and 74% of the PT wall. A comparison with a destructive examination of the crack demonstrated sensitivity too changes in crack depth accurate to 5% of the tube wall thickness. Such results, combined with similar information obtained from ultrasonics will increase confidence in interpretation of PT inspection data.

  2. On the Full-automatic Forming Technologies of S31803 Duplex Seamless Steel Tube%S31803双相无缝钢管全自动成型关键技术研究

    Institute of Scientific and Technical Information of China (English)

    章迪康; 孙作龙

    2013-01-01

    S31803 duplex stainless steel dominates the seamless steel tube market and has an increasingly output, for its struc-ture both has austenite and ferrite;it has the advantages of austenite steel and ferrite steel in function. But the stricter requirement and the weakness in forming process affect its promotion. Through such key technologies in full-automatic forming as online narrow gap automatic welding, online automatic cutting and slender thin wall polishing, succeed in developing full-automatic forming equipment of S31803 duplex and high pressure resistant seamless steel tube, solve the technical bottleneck of full-automatic forming in seamless steel tube.%  S31803双相不锈钢的组织结构既有奥氏体又有铁素体,在性能上兼具奥氏体不锈钢和铁素体不锈钢的优点,占据无缝钢管领域主导地位,但因产品要求更加严格及存在着成型工艺上的弱势而影响了推广使用。通过在线窄焊缝自动焊接、在线自动切割、细长薄壁管内抛光等全自动成型的关键技术研究,成功研发了S31803双相耐高压无缝钢管全自动成型设备,解决了无缝钢管全自动成型的技术瓶颈。

  3. Why Don't You See What I Mean? Prospects and Limitations of Current Automatic Sign Recognition Research

    Science.gov (United States)

    ten Holt, Gineke; Hendriks, Petra; Andriga, Tjeerd

    2006-01-01

    This article presents an overview of current automatic sign recognition research. A review of recent studies, as well as on our own research, has identified several problem areas that hamper successful sign recognition by a computer. Some of these problems are shared with automatic speech recognition, whereas others seem to be unique to automatic…

  4. Organ dose conversion coefficients for tube current modulated CT protocols for an adult population

    Science.gov (United States)

    Fu, Wanyi; Tian, Xiaoyu; Sahbaee, Pooyan; Zhang, Yakun; Segars, William Paul; Samei, Ehsan

    2016-03-01

    In computed tomography (CT), patient-specific organ dose can be estimated using pre-calculated organ dose conversion coefficients (organ dose normalized by CTDIvol, h factor) database, taking into account patient size and scan coverage. The conversion coefficients have been previously estimated for routine body protocol classes, grouped by scan coverage, across an adult population for fixed tube current modulated CT. The coefficients, however, do not include the widely utilized tube current (mA) modulation scheme, which significantly impacts organ dose. This study aims to extend the h factors and the corresponding dose length product (DLP) to create effective dose conversion coefficients (k factor) database incorporating various tube current modulation strengths. Fifty-eight extended cardiac-torso (XCAT) phantoms were included in this study representing population anatomy variation in clinical practice. Four mA profiles, representing weak to strong mA dependency on body attenuation, were generated for each phantom and protocol class. A validated Monte Carlo program was used to simulate the organ dose. The organ dose and effective dose was further normalized by CTDIvol and DLP to derive the h factors and k factors, respectively. The h factors and k factors were summarized in an exponential regression model as a function of body size. Such a population-based mathematical model can provide a comprehensive organ dose estimation given body size and CTDIvol. The model was integrated into an iPhone app XCATdose version 2, enhancing the 1st version based upon fixed tube current modulation. With the organ dose calculator, physicists, physicians, and patients can conveniently estimate organ dose.

  5. Distortions of Magnetic Flux Tubes in the Presence of Electric Currents

    Science.gov (United States)

    Malanushenko, Anna; Rempel, Matthias; Cheung, Mark

    2016-05-01

    Solar coronal loops possess several peculiar properties, which have been a subject of intensive research for a long time. These in particular include the lack of apparent expansion of coronal loops and the increased pressure scale height in loops compared to the diffuse background. Previously, Malanushenko & Schrijver (2013) proposed that these could be explained by the fact that magnetic flux tubes expand with height in a highly anisotropic manner. They used potential field models to demonstrate that flux tubes that have circular cross section at the photosphere, in the corona turn into a highly elongates structures, more resembling thick ribbons. Such ribbons, viewed along the expanding edge, would appear as thin, crisp structures of a constant cross-section with an increased pressure scale height, and when viewed along the non-expanding side, would appear as faint, wide and underdense features. This may also introduce a selection bias,when a set of loops is collected for a further study, towards those viewed along the expanding edge.However, some of the past studies have indicated that strong electric currents flowing in a given flux tube may result in the tube maintaining a relatively constant cross-sectional shape along its length. Given that Malanushenko & Schrijver (2013) focused on a potential, or current-free, field model of an active region, the extend to which their analysis could be applied to the real solar fields, was unclear.In the present study, we use a magnetic field created by MURaM, a highly realistic state-of-the-art radiative MHD code (Vogler et al, 2005; Rempel et al, 2009b). MURaM was shown to reproduce a wide variety of observed features of the solar corona (e.g., Hansteen et al, 2010; Cheung et al. 2007, 2008; Rempel 2009a,b). We analyze the distortions of magnetic flux tubes in a MURaM simulation of an active region corona. We quantify such distortions and correlate them with a number of relevant parameters of flux tubes, with a

  6. Eddy current inspection of tubing; Inspeccion de tubos por corrientes de Foucault

    Energy Technology Data Exchange (ETDEWEB)

    Bauza, J. L. R.; Herrero, J.; Diaz, J.

    1966-07-01

    The Experimental research work carried out to develop a Eddy current testing equipment is described. Search coils with ferrite or air cores were used and the obtained results are discussed. Valuable information was gained from a improved channel in which a direct measure of the defect and the reference signal phase difference is obtained. Artificial defect used to evaluate resolution and sensitivity were produced by electro-machining and mechanical means. Finned SAP tubing was tested in a routine basis with the described equipment and the results plotted. Basic and theoretical considerations on the Eddy current testing technique are given in the last section of this report. (Author)

  7. Monte Carlo simulations to assess the effects of tube current modulation on breast dose for multidetector CT

    OpenAIRE

    Angel, Erin; Yaghmai, Nazanin; Jude, Cecilia Matilda; Demarco, John J.; Cagnon, Christopher H.; Goldin, Jonathan G; Primak, Andrew N.; Stevens, Donna M.; Cody, Dianna D.; McCollough, Cynthia H.; McNitt-Gray, Michael F.

    2009-01-01

    Tube current modulation was designed to reduce radiation dose in CT imaging while maintaining overall image quality. This study aims to develop a method for evaluating the effects of tube current modulation (TCM) on organ dose in CT exams of actual patient anatomy. This method was validated by simulating a TCM and a fixed tube current chest CT exam on 30 voxelized patient models and estimating the radiation dose to each patient’s glandular breast tissue. This new method for estimating organ d...

  8. Modeling of tube current modulation methods in computed tomography dose calculations for adult and pregnant patients

    International Nuclear Information System (INIS)

    The comparatively high dose and increasing frequency of computed tomography (CT) examinations have spurred the development of techniques for reducing radiation dose to imaging patients. Among these is the application of tube current modulation (TCM), which can be applied either longitudinally along the body or rotationally along the body, or both. Existing computational models for calculating dose from CT examinations do not include TCM techniques. Dose calculations using Monte Carlo methods have been previously prepared for constant-current rotational exposures at various positions along the body and for the principle exposure projections for several sets of computational phantoms, including adult male and female and pregnant patients. Dose calculations from CT scans with TCM are prepared by appropriately weighting the existing dose data. Longitudinal TCM doses can be obtained by weighting the dose at the z-axis scan position by the relative tube current at that position. Rotational TCM doses are weighted using the relative organ doses from the principle projections as a function of the current at the rotational angle. Significant dose reductions of 15% to 25% to fetal tissues are found from simulations of longitudinal TCM schemes to pregnant patients of different gestational ages. Weighting factors for each organ in rotational TCM schemes applied to adult male and female patients have also been found. As the application of TCM techniques becomes more prevalent, the need for including TCM in CT dose estimates will necessarily increase. (author)

  9. Eddy current automatic inspection of heat exchangers in nuclear power stations

    International Nuclear Information System (INIS)

    This presentation describes the eddy current tube inspection techniques for heavy heat exchangers in nuclear power stations. The purpose of these eddy current tests, is first to determine the integrity of the heat exchanger tubes, and to characterize the related types of defects in each case following to their analysis and cause determination and subsequent inspection planning. This task requires a group highly qualified personnel with high tech automate equipment. The organization of the group required a correct function and task assignment in order to achieve efficiency in scheduling, with simultaneous inspection to different components in a continuous base and uninterruptedly. A lead specialist is in charge of the group, which is set up by several shift supervisors, a qualified tele manipulator installation crew a number of qualified tele manipulator operators, and the specialist for data acquisition and certified eddy current signal evaluators plus some other support technicians and administrations helpers. In order to comply with inspection requirements, a bunch of technical procedures had to be developed. The following equipment is available nowadays: Zetec SM-13, SM-23 and SM-22 tele manipulators for inspection probes positioning, with different shapes and configuration (rotating probes, flexible probes for U-Bends, and magnetic saturation probes endowed with their own driving units) and remote data acquisition units identified as MIZ-18 A and MIZ-30, which are remotely operated from a mobile lab installed in a trailer, outside the reactor building. The available equipment allows a simultaneous inspection of three different plant components (two steam generators and a moderator heat exchanger). We are also in a position of performing eddy current tube inspection in more than a NSP at the same time. The Zetec Eddynet software is used in the manipulator operation and for the data acquisition and defect evaluation. This software operates within Windows

  10. Dose reduction in spiral CT angiography of thoracic outlet syndrome by anatomically adapted tube current modulation

    Energy Technology Data Exchange (ETDEWEB)

    Mastora, I.; Remy-Jardin, M.; Remy, J. [Dept. of Radiology, University Center Hospital Calmette, Lille (France); Medical Research Group, Lille (France); Suess, C.; Scherf, C. [Siemens Medical Systems, Forcheim (Germany); Guillot, J.P. [Dept. of Radiology, University Center Hospital Calmette, Lille (France)

    2001-04-01

    The aim of this study was to evaluate dose reduction in spiral CT angiography of the thoracic outlet by on-line tube-current control. Prospectively, 114 patients undergoing spiral CT angiography of the subclavian artery for thoracic outlet arterial syndromes were evaluated with and without tube-current modulation at the same session (scanning parameters for the two successive angiograms, one in the neutral position and one after the postural maneuver): 140 kV; 206 mA; scan time 0.75 s; collimation 3 mm; pitch = (1). The dose reduction system was applied in the neutral position in the first 92 consecutive patients and after postural maneuver in the remaining 22 consecutive patients. Dose reduction and image quality were analyzed in the overall study group (group 1; n = 114). The influence of the arm position was assessed in 44 of the 114 patients (group 2), matched by the transverse diameter of the upper thorax. The mean dose reduction was 33 % in group 1 (range 22-40 %) and 34 % in group 2 (range 26-40 %). In group 2 the only difference in image quality was a significantly higher frequency of graininess on low-dose scans compared with reference scans whatever the patient's arm position, graded as minimal in 38 of the 44 patients (86 %). When the low-dose technique was applied after postural maneuver in group 2: (a) the mean dose reduction was significantly higher (35 vs 32 % in the neutral position; p = 0.006); (b) graininess was less frequent (82 vs 91 % in the neutral position); and (c) the percentage of graininess graded as minimal was significantly higher (83 vs 70 % in the neutral position; p = 0.2027). On-line tube-current modulation enables dose reduction on high-quality, diagnostic spiral CT angiograms of the thoracic outlet and should be applied during data acquisition in the neutral position and after postural maneuver for optimal use. (orig.)

  11. Finite element modeling of wall-loss sizing in a steam generator tube using a pulsed eddy current probe

    Science.gov (United States)

    Babbar, V. K.; Lepine, B.; Buck, J.; Underhill, P. R.; Morelli, J.; Krause, T. W.

    2015-03-01

    Inspection of steam generator (SG) tubes by conventional eddy current may, in general, involve analysis of indications from volumetric wall loss, cracks, fouling and support-plate degradation; however, it may be difficult to size or quantify effects from support-to-tube gap and tube tilt, especially in the presence of support plates. Pulsed eddy current (PEC) technology is being developed to investigate such complex tube and flaw geometries. The present work employs finite element modeling to investigate the effectiveness of PEC in identifying and sizing the outer diameter wall-loss in SG tubes. The signals analyzed using a modified principal components analysis (PCA) method reveal the potential success of a PEC-PCA combination to produce scores that can be used to size the wall-loss in the presence of support plates. The modeling results are in good agreement with experimental observations.

  12. Effect of x-ray tube current on the accuracy of cerebral perfusion parameters obtained by CT perfusion studies

    Science.gov (United States)

    Murase, Kenya; Nanjo, Takafumi; Satoshi, Ii; Miyazaki, Shohei; Hirata, Masaaki; Sugawara, Yoshifumi; Kudo, Masayuki; Sasaki, Kousuke; Mochizuki, Teruhito

    2005-11-01

    The purpose of this study was to investigate the effect of x-ray tube current on the accuracy of cerebral perfusion parameters obtained by CT perfusion studies using multi-detector row CT (MDCT). Following the standard CT perfusion study protocol, continuous (cine) scans (1 s/rotation × 60 s) consisting of four 5 mm thick contiguous slices were performed using an MDCT scanner with a tube voltage of 80 kVp and a tube current of 200 mA. We generated the simulated images with tube currents of 50 mA, 100 mA and 150 mA by adding the corresponding noise to the raw scan data of the original image acquired above using a noise simulation tool. From the original and simulated images, we generated the functional images of cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) in seven patients with cerebrovascular disease, and compared the correlation coefficients (CCs) between the perfusion parameter values obtained from the original and simulated images. The coefficients of variation (CVs) in the white matter were also compared. The CC values deteriorated with decreasing tube current. There was a significant difference between 50 mA and 100 mA for all perfusion parameters. The CV values increased with decreasing tube current. There were significant differences between 50 mA and 100 mA and between 100 mA and 150 mA for CBF. For CBV and MTT, there was also a significant difference between 150 mA and 200 mA. This study will be useful for understanding the effect of x-ray tube current on the accuracy of cerebral perfusion parameters obtained by CT perfusion studies using MDCT, and for selecting the tube current.

  13. Advanced eddy current technique for measurement of annular gap between pressure tube and calandria tube in Indian Pressurized Heavy Water Reactors (PHWRs)

    International Nuclear Information System (INIS)

    In Indian Pressurised Heavy Water Reactors (PHWRs), the PT (pressure tube) is designed to be nominally concentric with the encircling CT (calandria tube). Due to various factors PT becomes eccentric with respect to CT over the life of reactor. If this becomes excessive, hot PT will come in contact with cold CT. Such a cold spot could act as potential location for initiating blister formation and premature failure of PT. Hence it is important to periodically measure annular gap between PT and CT. An advanced eddy current technique has been successfully developed and incorporated in BARCIS (BARC Channel Inspection System) for measurement of PT-CT gap. (author). 4 refs., 3 figs

  14. Exploring the useful exposure range limits of three intraoral image receptors for various tube potential, tube current and exposure time settings

    OpenAIRE

    Ioannis A. Tsalafoutas; Panagiotis Gritzalis; Evripides Stefanou; Evangelos Georgiou; Emmanouel Yakoumakis; Elli Katsoni

    2011-01-01

    Objectives: To determine the useful exposure range limits of three intraoral image receptors of different technology when exposed to different X-ray beam spectra, dose and dose rate levels. Study Design: A dental X-ray unit offering a wide range of tube potential, tube current and exposure time settings was used to expose a dental quality control phantom. The receptors that were used to capture the radiographic images of the phantom were: the Kodak Insight, the Kodak RVG-6000 and the Duerr Vi...

  15. Improvement of ISI techniques by multi-frequency eddy current testing method for steam generator tube in PWR plant

    International Nuclear Information System (INIS)

    Eddy current flaw detection techniques are applied to the in-service inspection (ISI) of steam generator tubes in pressurized water reactors (PWR) plant. To improve the reliability and operating efficiency of the plants, efforts are being made to develop eddy current testing methods of various kinds. Multi-frequency eddy current testing method, one of new method, has recently been applied to actual heat exchanger tubes, contributing to the improvement of the detectability and signal evaluation of the ISI. The outline of multi-frequency eddy current testing method and its effects on the improvement of flaw detecting and signal evaluation accuracy are described. (author)

  16. Automatic orbital TIG-welding of small bore austenitic stainless steel tubes for nuclear fuel reprocessing plant

    International Nuclear Information System (INIS)

    Traditionally, manual welding techniques have been employed for shop and site fabrication of small bore austenitic stainless steel tubes in the nuclear fuel reprocessing plant of British Nuclear Fuels Limited (BNFL). This Paper describes an evaluation programme carried out to develop welding procedures for both 18Cr-13Ni-1Nb and 18Cr-10Ni low carbon stainless steel small bore tubing, the type of equipment used, and the modifications required for application to shop and site environments. (author)

  17. A pulsed eddy current probe for inspection of support plates from within Alloy-800 steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Krause, T. W.; Babbar, V. K.; Underhill, P. R. [Department of Physics, Royal Military College of Canada, Kingston, ON (Canada)

    2014-02-18

    Support plate degradation and fouling in nuclear steam generators (SGs) can lead to SG tube corrosion and loss of efficiency. Inspection and monitoring of these conditions can be integrated with preventive maintenance programs, thereby advancing station-life management processes. A prototype pulsed eddy current (PEC) probe, targeting inspection issues associated with SG tubes in SS410 tube support plate structures, has been developed using commercial finite element (FE) software. FE modeling was used to identify appropriate driver and pickup coil configurations for optimum sensitivity to changes in gap and offset for Alloy-800 SG tubes passing through 25 mm thick SS410 support plates. Experimental measurements using a probe that was manufactured based on the modeled configuration, were used to confirm the sensitivity of differential PEC signals to changes in relative position of the tube within the tube support plate holes. Models investigated the effect of shift and tilt of tube with respect to hole centers. Near hole centers and for small shifts, modeled signal amplitudes from the differentially connected coil pairs were observed to change linearly with tube shift. This was in agreement with experimentally measured TEC coil response. The work paves the way for development of a system targeting the inspection and evaluation of support plate structures in steam generators.

  18. A pulsed eddy current probe for inspection of support plates from within Alloy-800 steam generator tubes

    Science.gov (United States)

    Krause, T. W.; Babbar, V. K.; Underhill, P. R.

    2014-02-01

    Support plate degradation and fouling in nuclear steam generators (SGs) can lead to SG tube corrosion and loss of efficiency. Inspection and monitoring of these conditions can be integrated with preventive maintenance programs, thereby advancing station-life management processes. A prototype pulsed eddy current (PEC) probe, targeting inspection issues associated with SG tubes in SS410 tube support plate structures, has been developed using commercial finite element (FE) software. FE modeling was used to identify appropriate driver and pickup coil configurations for optimum sensitivity to changes in gap and offset for Alloy-800 SG tubes passing through 25 mm thick SS410 support plates. Experimental measurements using a probe that was manufactured based on the modeled configuration, were used to confirm the sensitivity of differential PEC signals to changes in relative position of the tube within the tube support plate holes. Models investigated the effect of shift and tilt of tube with respect to hole centers. Near hole centers and for small shifts, modeled signal amplitudes from the differentially connected coil pairs were observed to change linearly with tube shift. This was in agreement with experimentally measured TEC coil response. The work paves the way for development of a system targeting the inspection and evaluation of support plate structures in steam generators.

  19. Noise-based tube current reduction method with iterative reconstruction for reduction of radiation exposure in coronary CT angiography

    International Nuclear Information System (INIS)

    Purpose: To investigate the potential of noise-based tube current reduction method with iterative reconstruction to reduce radiation exposure while achieving consistent image quality in coronary CT angiography (CCTA). Materials and methods: 294 patients underwent CCTA on a 64-detector row CT equipped with iterative reconstruction. 102 patients with fixed tube current were assigned to Group 1, which was used to establish noise-based tube current modulation formulas, where tube current was modulated by the noise of test bolus image. 192 patients with noise-based tube current were randomly assigned to Group 2 and Group 3. Filtered back projection was applied for Group 2 and iterative reconstruction for Group 3. Qualitative image quality was assessed with a 5 point score. Image noise, signal intensity, volume CT dose index, and dose-length product were measured. Results: The noise-based tube current modulation formulas were established through regression analysis using image noise measurements in Group 1. Image noise was precisely maintained at the target value of 35.00 HU with small interquartile ranges for Group 2 (34.17–35.08 HU) and Group 3 (34.34–35.03 HU), while it was from 28.41 to 36.49 HU for Group 1. All images in the three groups were acceptable for diagnosis. A relative 14% and 41% reduction in effective dose for Group 2 and Group 3 were observed compared with Group 1. Conclusion: Adequate image quality could be maintained at a desired and consistent noise level with overall 14% dose reduction using noise-based tube current reduction method. The use of iterative reconstruction further achieved approximately 40% reduction in effective dose

  20. CT angiography of the neck: Value of contrast medium dose reduction with low tube voltage and high tube current in a 64–detector row CT

    International Nuclear Information System (INIS)

    Aim: To evaluate the feasibility of a low-dose contrast medium protocol for 64-detector row computed tomography angiography (CTA) of the neck using a low-tube-voltage/high-tube-current setting. Materials and methods: A phantom study was performed using 64-detector row spiral CT at multiple tube voltage and current settings. Iodine contrast medium attenuation curves were acquired by processing and used to select the best contrast medium-to-noise ratio (CNR). A prospective clinical study was then performed on 84 patients requiring neck CTA. Patients were randomly divided into two groups of 42. Group A was examined using the conventional imaging protocol (120 kV, 400 mAs) and group B was examined at 80 kV and 600 mAs along with a 50% reduction in contrast medium dose. The CT dose index-volume (CTDIvol), background noise (BN), and CNR were measured and statistically analysed. Various image quality criteria were evaluated by two senior radiologists using a qualitative five-point scale. Results: Comparing group B with A, CTDIvol decreased by 54% (B: 27.48 mGy, A: 59.11 mGy), however, the CNR increased by 50%. The mean attenuation, which was caused by venous streak artefacts, was significantly lower in group B than A. Qualitative image analysis found that all criteria were significantly better for group B than A. Conclusion: At 64-detector row spiral CT, the low-tube-voltage/high-tube-current with low-dose contrast medium protocol was superior to the conventional protocol regarding radiation dose, venous streak artefacts, and image quality, and is feasible for CTA of the neck

  1. Influence of tube voltage and current on in-line phase contrast imaging using a microfocus x-ray source

    Institute of Scientific and Technical Information of China (English)

    Li Zheng; Yu Ai-Min; Li Cheng-Quan

    2007-01-01

    In-line x-ray phase contrast imaging has attracted much attention due to two major advantages:its effectiveness in imaging weakly absorbing materials,and the simplicity of its facilities.In this paper a comprehensive theory based on Wigner distribution developed by Wu and Liu [Med.Phys.31 2378-2384(2004)] is reviewed.The influence of x-ray source and detector on the image is discussed.Experiments using a microfocus x-ray source and a CCD detector are conducted,which show the role of two key factors on imaging:the tube voltage and tube current.High tube current and moderate tube voltage are suggested for imaging.

  2. Achieving consistent image quality and overall radiation dose reduction for coronary CT angiography with body mass index-dependent tube voltage and tube current selection

    International Nuclear Information System (INIS)

    Aim: To develop a quantitative body mass index (BMI)-dependent tube voltage and tube current selection method for obtaining consistent image quality and overall dose reduction in computed tomography coronary angiography (CTCA). Methods and materials: The images of 190 consecutive patients (group A) who underwent CTCA with fixed protocols (100 kV/193 mAs for 100 patients with a BMI of <27 and 120 kV/175 mAs for 90 patients with a BMI of >27) were retrospectively analysed and reconstructed with an adaptive statistical iterative reconstruction (ASIR) algorithm at 50% blending. Image noise was measured and the relationship to BMI was studied to establish BMI-dependent tube current for obtaining CTCA images with user-specified image noise. One hundred additional cardiac patients (group B) were examined using prospective triggering with the BMI-dependent tube voltage/current. CTCA image-quality score, image noise, and effective dose from groups B and C (subgroup of A of 100 patients examined with prospective triggering only) were obtained and compared. Results: There was a linear relationship between image noise and BMI in group A. Using a BMI-dependent tube current in group B, an average CTCA image noise of 27.7 HU (target 28 HU) and 31.7 HU (target 33 HU) was obtained for the subgroups of patients with BMIs of >27 and of <27, respectively, and was independent of patient BMI. There was no difference between image-quality scores between groups B and C (4.52 versus 4.60, p > 0.05). The average effective dose for group B (2.56 mSv) was 42% lower than group C (4.38 mSv; p < 0.01). Conclusion: BMI-dependent tube voltage/current selection in CTCA provides an individualized protocol that generates consistent image quality and helps to reduce overall patient radiation dose. - Highlights: • BMI-dependent kVp and mA selection method may be established in CCTA. • BMI-dependent kVp and mA enables consistent CCTA image quality. • Overall dose reduction of 40% can

  3. Multi-detector row CT scanning in Paleoanthropology at various tube current settings and scanning mode.

    Science.gov (United States)

    Badawi-Fayad, J; Yazbeck, C; Balzeau, A; Nguyen, T H; Istoc, A; Grimaud-Hervé, D; Cabanis, E- A

    2005-12-01

    The purpose of this study was to determine the optimal tube current setting and scanning mode for hominid fossil skull scanning, using multi-detector row computed tomography (CT). Four fossil skulls (La Ferrassie 1, Abri Pataud 1, CroMagnon 2 and Cro-Magnon 3) were examined by using the CT scanner LightSpeed 16 (General Electric Medical Systems) with varying dose per section (160, 250, and 300 mAs) and scanning mode (helical and conventional). Image quality of two-dimensional (2D) multiplanar reconstructions, three-dimensional (3D) reconstructions and native images was assessed by four reviewers using a four-point grading scale. An ANOVA (analysis of variance) model was used to compare the mean score for each sequence and the overall mean score according to the levels of the scanning parameters. Compared with helical CT (mean score=12.03), the conventional technique showed sustained poor image quality (mean score=4.17). With the helical mode, we observed a better image quality at 300 mAs than at 160 in the 3D sequences (P=0.03). Whereas in native images, a reduction in the effective tube current induced no degradation in image quality (P=0.05). Our study suggests a standardized protocol for fossil scanning with a 16 x 0.625 detector configuration, a 10 mm beam collimation, a 0.562:1 acquisition mode, a 0.625/0.4 mm slice thickness/reconstruction interval, a pitch of 5.62, 120 kV and 300 mAs especially when a 3D study is required. PMID:16211320

  4. 换热器管板角焊缝相控阵自动超声检测技术研究%Research on Phased Array Automatically Ultrasonic Testing Technique of Tube to Tube-sheet Welds in Heat Exchanger

    Institute of Scientific and Technical Information of China (English)

    郭伟灿; 钱盛杰; 凌张伟

    2015-01-01

    在换热器的制作过程中,换热管与管板常采用焊接形式,焊缝的质量是保证换热器长期正常运行的关键。常规的超声检测方法具有系统复杂、检测效率低等缺点。因此,提出了相控阵超声检测技术,并开发了相控阵超声检测系统,以实现对管板角焊缝的自动超声检测。系统由周向步进电机实现周向扫查,纵向扫查采用相控阵探头电子线扫查,从而实现超声 C 扫描检测。通过带有气孔、未熔合等典型缺陷对检测系统进行试验研究。结果表明,该技术可以有效地检测出换热器管板角焊缝中的典型缺陷。%In the process of produce heat exchangers,heat exchanger′s tube and tube sheet conjunction adopt the form of welding,the quality of welding is the key insurance for the long and normal operation of the heat exchangers.The conventional ultrasonic testing method has many disadvantages like complicated system and low efficiency of detection.Thus,it puts forward the phased array ultrasonic testing technique and develops the ultrasonic testing system to accomplish the automatically ultrasonic testing of the tube to tube-sheet welds.The ultrasonic C-scan was carried out by the ultrasonic testing system with its circumfer-ential scanning by a mechanical scanning device while the axial electronic linear scanning by the phased array probe.At last,the tests on samples with typical flaws such as porosity flaws and the incomplete fu-sion flaws were performed by the ultrasonic testing system.Experiment results showed that the phased ar-ray ultrasonic technique could effectively detect the typical flaws in the tube to tube-sheet welds of heat exchanger.

  5. Electromagnetic and beam dynamics studies of a high current drift tube linac for LEHIPA

    Science.gov (United States)

    Roy, S.; Rao, S. V. L. S.; Pande, R.; Krishnagopal, S.; Singh, P.

    2014-06-01

    We have performed detailed electromagnetic and beam dynamics studies of a 352.21 MHz drift-tube linac (DTL) that will accelerate a 30 mA CW proton beam from 3 to 20 MeV. At such high currents space charge effects are important, and therefore the effect of linear as well as non-linear space charge has been studied (corresponding to uniform and Gaussian initial beam distributions), in order to avoid space charge instabilities. To validate the electromagnetic simulations, a 1.2 m long prototype of the DTL was fabricated. RF measurements performed on the prototype were in good agreement with the simulations. A detailed simulation study of beam halos was also performed, which showed that beyond a current of 10 mA, significant longitudinal beam halos are excited even for a perfectly matched beam, whereas for a mis-matched beam transverse beam halos are also excited. However, these do not lead to any beam loss within the DTL.

  6. A technique for automatic tubing occlusion in response to air bubble detection when using a centrifugal pump.

    Science.gov (United States)

    Paulsen, A W; Hargadine, W L; Lambert, G S; Long, A C

    1990-01-01

    A double acting pneumatically powered cylinder, energized by an electrically activated solenoid valve, is used to occlude the outflow line from a Bio-Medicus (a) constrained vortex pump. The cylinder is mounted on a tubing guide that is fastened to a pole clamp. A Sarns (b) air bubble detector, placed on the pump inflow line is used to provide the signal to activate the solenoid valve. The outflow occluder is capable of 100% occlusion of 3/8 x 3/32 inch Tygon tubing up to pressures of 2586 mmHg. The occluder system is able to work with many types of bubble detectors and is applicable to any form of non-occlusive pump.

  7. The impact on CT dose of the variability in tube current modulation technology: a theoretical investigation

    Science.gov (United States)

    Li, Xiang; Segars, W. Paul; Samei, Ehsan

    2014-08-01

    Body CT scans are routinely performed using tube-current-modulation (TCM) technology. There is notable variability across CT manufacturers in terms of how TCM technology is implemented. Some manufacturers aim to provide uniform image noise across body regions and patient sizes, whereas others aim to provide lower noise for smaller patients. The purpose of this study was to conduct a theoretical investigation to understand how manufacturer-dependent TCM scheme affects organ dose, and to develop a generic approach for assessing organ dose across TCM schemes. The adult reference female extended cardiac-torso (XCAT) phantom was used for this study. A ray-tracing method was developed to calculate the attenuation of the phantom for a given projection angle based on phantom anatomy, CT system geometry, x-ray energy spectrum, and bowtie filter filtration. The tube current (mA) for a given projection angle was then calculated as a log-linear function of the attenuation along that projection. The slope of this function, termed modulation control strength, α, was varied from 0 to 1 to emulate the variability in TCM technology. Using a validated Monte Carlo program, organ dose was simulated for five α values (α = 0, 0.25, 0.5, 0.75, and 1) in the absence and presence of a realistic system mA limit. Organ dose was further normalized by volume-weighted CT dose index (CTDIvol) to obtain conversion factors (h factors) that are relatively independent of system specifics and scan parameters. For both chest and abdomen-pelvis scans and for 24 radiosensitive organs, organ dose conversion factors varied with α, following second-order polynomial equations. This result suggested the need for α-specific organ dose conversion factors (i.e., conversion factors specific to the modulation scheme used). On the other hand, across the full range of α values, organ dose in a TCM scan could be derived from the conversion factors established for a fixed-mA scan (hFIXED). This was possible by

  8. Convolution-based estimation of organ dose in tube current modulated CT

    Science.gov (United States)

    Tian, Xiaoyu; Segars, W. Paul; Dixon, Robert L.; Samei, Ehsan

    2016-05-01

    Estimating organ dose for clinical patients requires accurate modeling of the patient anatomy and the dose field of the CT exam. The modeling of patient anatomy can be achieved using a library of representative computational phantoms (Samei et al 2014 Pediatr. Radiol. 44 460-7). The modeling of the dose field can be challenging for CT exams performed with a tube current modulation (TCM) technique. The purpose of this work was to effectively model the dose field for TCM exams using a convolution-based method. A framework was further proposed for prospective and retrospective organ dose estimation in clinical practice. The study included 60 adult patients (age range: 18-70 years, weight range: 60-180 kg). Patient-specific computational phantoms were generated based on patient CT image datasets. A previously validated Monte Carlo simulation program was used to model a clinical CT scanner (SOMATOM Definition Flash, Siemens Healthcare, Forchheim, Germany). A practical strategy was developed to achieve real-time organ dose estimation for a given clinical patient. CTDIvol-normalized organ dose coefficients ({{h}\\text{Organ}} ) under constant tube current were estimated and modeled as a function of patient size. Each clinical patient in the library was optimally matched to another computational phantom to obtain a representation of organ location/distribution. The patient organ distribution was convolved with a dose distribution profile to generate {{≤ft(\\text{CTD}{{\\text{I}}\\text{vol}}\\right)}\\text{organ, \\text{convolution}}} values that quantified the regional dose field for each organ. The organ dose was estimated by multiplying {{≤ft(\\text{CTD}{{\\text{I}}\\text{vol}}\\right)}\\text{organ, \\text{convolution}}} with the organ dose coefficients ({{h}\\text{Organ}} ). To validate the accuracy of this dose estimation technique, the organ dose of the original clinical patient was estimated using Monte Carlo program with TCM profiles explicitly modeled. The

  9. Convolution-based estimation of organ dose in tube current modulated CT

    Science.gov (United States)

    Tian, Xiaoyu; Segars, W. Paul; Dixon, Robert L.; Samei, Ehsan

    2016-05-01

    Estimating organ dose for clinical patients requires accurate modeling of the patient anatomy and the dose field of the CT exam. The modeling of patient anatomy can be achieved using a library of representative computational phantoms (Samei et al 2014 Pediatr. Radiol. 44 460–7). The modeling of the dose field can be challenging for CT exams performed with a tube current modulation (TCM) technique. The purpose of this work was to effectively model the dose field for TCM exams using a convolution-based method. A framework was further proposed for prospective and retrospective organ dose estimation in clinical practice. The study included 60 adult patients (age range: 18–70 years, weight range: 60–180 kg). Patient-specific computational phantoms were generated based on patient CT image datasets. A previously validated Monte Carlo simulation program was used to model a clinical CT scanner (SOMATOM Definition Flash, Siemens Healthcare, Forchheim, Germany). A practical strategy was developed to achieve real-time organ dose estimation for a given clinical patient. CTDIvol-normalized organ dose coefficients ({{h}\\text{Organ}} ) under constant tube current were estimated and modeled as a function of patient size. Each clinical patient in the library was optimally matched to another computational phantom to obtain a representation of organ location/distribution. The patient organ distribution was convolved with a dose distribution profile to generate {{≤ft(\\text{CTD}{{\\text{I}}\\text{vol}}\\right)}\\text{organ, \\text{convolution}}} values that quantified the regional dose field for each organ. The organ dose was estimated by multiplying {{≤ft(\\text{CTD}{{\\text{I}}\\text{vol}}\\right)}\\text{organ, \\text{convolution}}} with the organ dose coefficients ({{h}\\text{Organ}} ). To validate the accuracy of this dose estimation technique, the organ dose of the original clinical patient was estimated using Monte Carlo program with TCM profiles explicitly modeled

  10. Optimization of recommendations for abdomen computerized tomography based on reconstruction filters, voltage and tube current

    International Nuclear Information System (INIS)

    The use of computed tomography has increased significantly over the past decades. In Brazil the use increased more than twofold from 2008 to 2014, in the meantime the abdomen procedures have tripled. The high frequency of this procedure combined by the increasing collective radiation dose in medical exposures, has resulted development tools to maximize the benefit in CT images. This work aimed to establish protocols optimized in abdominal CT through acquisitions parameters and reconstructions techniques based on filters kernels. A sample of patients undergoing abdominal CT in a diagnostic center of Rio de Janeiro was assessed. Had been collected patients information and acquisitions parameters. The phantoms CT image acquisitions were performed by using different voltage values by adjusting the tube current (mAs) to obtain the same value from CTDIvol patients with normal BMI. Afterwards, the CTDIvol values were reduced by 30%, 50% and 60%. All images were reconstructed with low-contrast filters (A) and standard filters (B). The CTDIvol values for patients with normal BMI were 7% higher than in patients with underweight BMI and 30%, 50% and 60% lower than the overweight, obese I and III patients, respectively. The evaluations of image quality showed that variation of the current (mA) and the reconstruction filters did not affect the Hounsfield values. When the contrast-to-noise ratio (CNR) was normalized to CTDIvol, the protocols acquired with 60% reduction of CTDIvol with 140 kV and 80 kV showed CNR 6% lower than the routine. Modifications of the acquisition parameters did not affect spatial resolution, but the post-processing with B filters reduced the spatial frequency by 16%. With reduced the dose of 30%, lesions in the spleen had the CNR higher than 10% routine protocols with 140 kV acquired and post-processed to filter A. The image post-processing with a filter A with a 80kV voltage provided CNR values equal to the routine for the liver lesions with a 30

  11. Development of a multi-channel eddy current examination system for automated inspection of steam generator tubing

    International Nuclear Information System (INIS)

    A segmented absolute 8-coil probe for inspection of heat exchanger tubing has been developed together with the appropriate multi-channel eddy current instrument and evaluation algorithm. The system has been qualified in the laboratory by tests on artificially induced flaws and in field by comparing results obtained on actual flaws with data from ultrasonic wall thickness measurements. (author)

  12. Estimation of breast dose saving potential using a breast positioning technique for organ-based tube current modulated CT

    Science.gov (United States)

    Fu, Wanyi; Tian, Xiaoyu; Sturgeon, Gregory; Agasthya, Greeshma; Segars, William Paul; Goodsitt, Mitchell M.; Kazerooni, Ella A.; Samei, Ehsan

    2016-04-01

    In thoracic CT, organ-based tube current modulation (OTCM) reduces breast dose by lowering the tube current in the 120° anterior dose reduction zone of patients. However, in practice the breasts usually expand to an angle larger than the dose reduction zone. This work aims to simulate a breast positioning technique (BPT) to constrain the breast tissue to within the dose reduction zone for OTCM and to evaluate the corresponding potential reduction in breast dose. Thirteen female anthropomorphic computational phantoms were studied (age range: 27-65 y.o., weight range: 52-105.8 kg). Each phantom was modeled in the supine position with and without application of the BPT. Attenuation-based tube current (ATCM, reference mA) was generated by a ray-tracing program, taking into account the patient attenuation change in the longitudinal and angular plane (CAREDose4D, Siemens Healthcare). OTCM was generated by reducing the mA to 20% between +/- 60° anterior of the patient and increasing the mA in the remaining projections correspondingly (X-CARE, Siemens Healthcare) to maintain the mean tube current. Breast tissue dose was estimated using a validated Monte Carlo program for a commercial scanner (SOMATOM Definition Flash, Siemens Healthcare). Compared to standard tube current modulation, breast dose was significantly reduced using OTCM by 19.8+/-4.7%. With the BPT, breast dose was reduced by an additional 20.4+/-6.5% to 37.1+/-6.9%, using the same CTDIvol. BPT was more effective for phantoms simulating women with larger breasts with the average breast dose reduction of 30.2%, 39.2%, and 49.2% from OTCMBP to ATCM, using the same CTDIvol for phantoms with 0.5, 1.5, and 2.5 kg breasts, respectively. This study shows that a specially designed BPT improves the effectiveness of OTCM.

  13. Ambipolar Diffusion in Direct-Current Positive Column with Variations in Radius of Discharge Tube

    Institute of Scientific and Technical Information of China (English)

    D. AKBAR; S. BILIKMEN

    2006-01-01

    @@ The ambipolar diffusion and argon ion mobility as functions of the reduced electric field and pressure times the tube radius are investigated in a weakly ionized non-uniform glow discharge plasma system.

  14. In service inspection of steam generator tubes with a multifrequence eddy current apparatus

    International Nuclear Information System (INIS)

    The described multifrequency device has been designed and developed for a complete testing of tubes. It is necessary to eliminate the signals given by plates, expanded parts, background noises and magnetic signals which can mask some possible defects

  15. Inspection performance of eddy current probe for in-service inspection of HTTR intermediate heat exchanger tubes

    International Nuclear Information System (INIS)

    An experimental study was carried out to clarify the inspection performance of an eddy current probe for the inservice inspection of the intermediate heat exchanger (IHX) tubes of the high-temperature engineering test reactor. Test tubes were made of the same material (Hastelloy XR) and dimensions as those of the IHX, and had artificial discontinuities with reference to the standards of steam generator tubes in ASME Boiler and Pressure Vessel Code which were conservative for the IHX tubes. It was confirmed that the inspection performance of the probe satisfied the ASME standards in the base metal. The probe also could detect discontinuities such as a 90deg circumferential groove with 0.5 mm in width and 20% through from the outer tube surface, and a 100% through-wall hole with 0.5 mm in diameter. The inspection performance was lowered for discontinuities in the welded joint, and flat bottom holes with 1.7 mm in diameter were not detected. The inspection limit of 90deg circumferential grooves with 1.5 mm in width, was above 60% in depth for outer surface and 20% in depth for inner surface in the welded joint. (author)

  16. Prospective ECG-triggered coronary CT angiography: clinical value of noise-based tube current reduction method with iterative reconstruction.

    Directory of Open Access Journals (Sweden)

    Junlin Shen

    Full Text Available OBJECTIVES: To evaluate the clinical value of noise-based tube current reduction method with iterative reconstruction for obtaining consistent image quality with dose optimization in prospective electrocardiogram (ECG-triggered coronary CT angiography (CCTA. MATERIALS AND METHODS: We performed a prospective randomized study evaluating 338 patients undergoing CCTA with prospective ECG-triggering. Patients were randomly assigned to fixed tube current with filtered back projection (Group 1, n = 113, noise-based tube current with filtered back projection (Group 2, n = 109 or with iterative reconstruction (Group 3, n = 116. Tube voltage was fixed at 120 kV. Qualitative image quality was rated on a 5-point scale (1 = impaired, to 5 = excellent, with 3-5 defined as diagnostic. Image noise and signal intensity were measured; signal-to-noise ratio was calculated; radiation dose parameters were recorded. Statistical analyses included one-way analysis of variance, chi-square test, Kruskal-Wallis test and multivariable linear regression. RESULTS: Image noise was maintained at the target value of 35HU with small interquartile range for Group 2 (35.00-35.03HU and Group 3 (34.99-35.02HU, while from 28.73 to 37.87HU for Group 1. All images in the three groups were acceptable for diagnosis. A relative 20% and 51% reduction in effective dose for Group 2 (2.9 mSv and Group 3 (1.8 mSv were achieved compared with Group 1 (3.7 mSv. After adjustment for scan characteristics, iterative reconstruction was associated with 26% reduction in effective dose. CONCLUSION: Noise-based tube current reduction method with iterative reconstruction maintains image noise precisely at the desired level and achieves consistent image quality. Meanwhile, effective dose can be reduced by more than 50%.

  17. Study of methods for testing the tubes of steam generators by means of Eddy Current

    International Nuclear Information System (INIS)

    Comparative studies of equipment have been performed at Ringhals. Automatic testing systems, type Vincotte have been found to be flexible. Multi-frequency systems are to be preferred. The limits of detection of defects can be estimated in three classes including defects which are impossible to detect. Real defects in Ringhals-2 and Ringhals-3 were used as reference. (G.B.)

  18. The effects of surface tension on flooding in counter-current two-phase flow in an inclined tube

    Energy Technology Data Exchange (ETDEWEB)

    Deendarlianto [Department of Mechanical and Industrial Engineering, Faculty of Engineering, Gadjah Mada University, Jalan Grafika No.2 Yogyakarta 55281 (Indonesia); Forschungszentrum Dresden-Rossendorf e.V., Institute of Safety Research, P.O. Box 510 119, D-01314 Dresden (Germany); Ousaka, Akiharu [Department of Mechanical Engineering, The University of Tokushima, 2-1 Minami Josanjima, Tokushima 770-8506 (Japan); Indarto [Department of Mechanical and Industrial Engineering, Faculty of Engineering, Gadjah Mada University, Jalan Grafika No.2 Yogyakarta 55281 (Indonesia); Kariyasaki, Akira [Department of Chemical Engineering, Fukuoka University, 8-19-1, Jyonan-ku, Fukuoka 814-0180 (Japan); Lucas, Dirk; Vallee, Christophe [Forschungszentrum Dresden-Rossendorf e.V., Institute of Safety Research, P.O. Box 510 119, D-01314 Dresden (Germany); Vierow, Karen; Hogan, Kevin [Department of Nuclear Engineering Texas A and M University, 129 Zachry Engineering Center, 3133 TAMU College Station, TX 77843-3133 (United States)

    2010-10-15

    The purpose of the present study is to investigate the effects of surface tension on flooding phenomena in counter-current two-phase flow in an inclined tube. Previous studies by other researchers have shown that surface tension has a stabilizing effect on the falling liquid film under certain conditions and a destabilizing or unclear trend under other conditions. Experimental results are reported herein for air-water systems in which a surfactant has been added to vary the liquid surface tension without altering other liquid properties. The flooding section is a tube of 16 mm in inner diameter and 1.1 m length, inclined at 30-60 from horizontal. The flooding mechanisms were observed by using two high-speed video cameras and by measuring the time variation of liquid hold-up along the test tube. The results show that effects of surface tension are significant. The gas velocity needed to induce flooding is lower for a lower surface tension. There was no upward motion of the air-water interfacial waves upon flooding occurrence, even for lower a surface tension. Observations on the liquid film behavior after flooding occurred suggest that the entrainment of liquid droplets plays an important role in the upward transport of liquid. Finally, an empirical correlation for flooding velocities is proposed that includes functional dependencies on surface tension and tube inclination. (author)

  19. Application of wavelet analysis to signal processing for Eddy--Current Testing of FBR steam generator tubes

    International Nuclear Information System (INIS)

    We have been studying an advanced signal processing method for ECT (Eddy-Current Testing) to detect flaws in heat exchanger tubes of steam generators in a FBR (Fast Breeder Reactor) plant. The data obtained from the testing of these steam generator tubes showed some noise characteristics different from ones in light water reactor plants. Thus, an improvement of the signal-to-noise ratio of the processed ECT data is desired in order to increase reliability of the inspection. We have evaluated the signal-to-noise ratio as a performance measure using the actual plant data by means of wavelet analysis technique, which has been applied successfully in many fields to detect anomalous signals. First, we synthesized an ECT data containing flaws by combining the noisy signals from an in-field inspection of one heat exchanger tube with separately measured flaw signals from a calibration piece that had various machined flaws. Next, we evaluated the performance of the wavelet analysis technique by comparing it with a reference Fourier method. The performance of this technique is much better than by conventional analysis. For example, the signal-to-noise ratio of the discrete wavelet analysis method is 1.4 times greater than that by a conventional, low-pass filter method. Thus, we have shown that wavelet analysis has advantages over conventional method of detecting flaws in FBR steam generator tubes because of its sensitivity to localized events, such as sudden signal changes. (author)

  20. SU-E-I-37: Eye Lens Dose Reduction From CT Scan Using Organ Based Tube Current Modulation

    International Nuclear Information System (INIS)

    Purpose: To investigate the eye lens dose reduction by CT scan with organ based tube current modulation (OBTCM) using GPU Monte Carlo code ARCHER-CT. Methods: 36 X-ray sources and bowtie filters were placed around the patient head with the projection angle interval of 10° for one rotation of CT scan, each projection was simulated respectively. The voxel eye models with high resolution(0.1mm*0.1mm*0.1mm) were used in the simulation and different tube voltage including 80kVp, 100kVp, 120kVp and 140kVp were taken into consideration. Results: The radiation doses to the eye lens increased with the tube voltage raised from 80kVp to 140kVp, and the dose results from 0° (AP) direction are much higher than those from 180° (PA) direction for all the 4 different tube voltage investigated. This 360° projection dose characteristic enables organ based TCM, which can reduce the eye lens dose by more than 55%. Conclusion: As the eye lens belongs to superficial tissues, its radiation dose to external exposure like CT is direction sensitive, and this characteristic feature makes organ based TCM to be an effective way to reduce the eye lens dose, so more clinical use of this technique were recommended. National Nature Science Foundation of China(No.11475047)

  1. Effects of automatic tube potential selection on radiation dose index, image quality, and lesion detectability in pediatric abdominopelvic CT and CTA: a phantom study

    International Nuclear Information System (INIS)

    To assess the effect of automatic tube potential selection (ATPS) on radiation dose, image quality, and lesion detectability in paediatric abdominopelvic CT and CT angiography (CTA). A paediatric modular phantom with contrast inserts was examined with routine pitch (1.4) and high pitch (3.0) using a standard abdominopelvic protocol with fixed 120 kVp, and ATPS with variable kVp in non-contrast, contrast-enhanced, and CTA mode. The volume CT dose index (CTDIvol), contrast-to-noise ratio (CNR) and lesion detectability index (d') were compared between the standard protocol and ATPS examinations. CTDIvol was reduced in all routine pitch ATPS examinations, with dose reductions of 27-52 % in CTA mode (P < 0.0001), 15-33 % in contrast-enhanced mode (P = 0.0003) and 8-14 % in non-contrast mode (P = 0.03). Iodine and soft tissue insert CNR and d' were improved or maintained in all ATPS examinations. kVp and dose were reduced in 25 % of high pitch ATPS examinations and in none of the full phantom examinations obtained after a single full phantom localizer. ATPS reduces radiation dose while maintaining image quality and lesion detectability in routine pitch paediatric abdominopelvic CT and CTA, but technical factors such as pitch and imaging range must be considered to optimize ATPS benefits. (orig.)

  2. Effects of automatic tube potential selection on radiation dose index, image quality, and lesion detectability in pediatric abdominopelvic CT and CTA: a phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Brinkley, Michael F.; Choudhury, Kingshuk Roy; Frush, Donald P. [Duke University School of Medicine, Department of Radiology, DUMC Box 3808, Durham, NC (United States); Ramirez-Giraldo, Juan C. [Siemens Healthcare, Malvern (United States); Samei, Ehsan; Wilson, Joshua M.; Christianson, Olav I. [Duke University School of Medicine, Clinical Imaging Physics Group, Department of Radiology, Durham, NC (United States); Frush, Daniel J. [Duke University School of Medicine, Medical Physics, Durham, NC (United States)

    2016-01-15

    To assess the effect of automatic tube potential selection (ATPS) on radiation dose, image quality, and lesion detectability in paediatric abdominopelvic CT and CT angiography (CTA). A paediatric modular phantom with contrast inserts was examined with routine pitch (1.4) and high pitch (3.0) using a standard abdominopelvic protocol with fixed 120 kVp, and ATPS with variable kVp in non-contrast, contrast-enhanced, and CTA mode. The volume CT dose index (CTDI{sub vol}), contrast-to-noise ratio (CNR) and lesion detectability index (d') were compared between the standard protocol and ATPS examinations. CTDI{sub vol} was reduced in all routine pitch ATPS examinations, with dose reductions of 27-52 % in CTA mode (P < 0.0001), 15-33 % in contrast-enhanced mode (P = 0.0003) and 8-14 % in non-contrast mode (P = 0.03). Iodine and soft tissue insert CNR and d' were improved or maintained in all ATPS examinations. kVp and dose were reduced in 25 % of high pitch ATPS examinations and in none of the full phantom examinations obtained after a single full phantom localizer. ATPS reduces radiation dose while maintaining image quality and lesion detectability in routine pitch paediatric abdominopelvic CT and CTA, but technical factors such as pitch and imaging range must be considered to optimize ATPS benefits. (orig.)

  3. Automatic Condition Monitoring of Industrial Rolling-Element Bearings Using Motor’s Vibration and Current Analysis

    DEFF Research Database (Denmark)

    Yang, Zhenyu

    2015-01-01

    An automatic condition monitoring for a class of industrial rolling-element bearings is developed based on the vibration as well as stator current analysis. The considered fault scenarios include a single-point defect, multiple-point defects, and a type of distributed defect. Motivated by the pot......An automatic condition monitoring for a class of industrial rolling-element bearings is developed based on the vibration as well as stator current analysis. The considered fault scenarios include a single-point defect, multiple-point defects, and a type of distributed defect. Motivated...... by the potential commercialization, the developed system is promoted mainly using off-the-shelf techniques, that is, the high-frequency resonance technique with envelope detection and the average of short-time Fourier transform. In order to test the flexibility and robustness, the monitoring performance...... is extensively studied under diverse operating conditions: different sensor locations, motor speeds, loading conditions, and data samples from different time segments. The experimental results showed the powerful capability of vibration analysis in the bearing point defect fault diagnosis. The current analysis...

  4. Investigation of eddy current examination on OD fatigue crack for steam generator tubes

    Science.gov (United States)

    Kong, Yuying; Ding, Boyuan; Li, Ming; Liu, Jinhong; Chen, Huaidong; Meyendorf, Norbert G.

    2015-03-01

    The opening width of fatigue crack was very small, and conventional Bobbin probe was very difficult to detect it in steam generator tubes. Different sizes of 8 fatigue cracks were inspected using bobbin probe rotating probe. The analysis results showed that, bobbin probe was not sensitive for fatigue crack even for small through wall crack mixed with denting signal. On the other hand, the rotating probe was easily to detect all cracks. Finally, the OD phase to depth curve for fatigue crack using rotating probe was established and the results agreed very well with the true crack size.

  5. Nondestructive inspection of the tubes of TRIGA IPR-R1 reactor heat exchanger by eddy current testing

    Energy Technology Data Exchange (ETDEWEB)

    Silva Junior, Silverio F.; Silva, Roger F.; Oliveira, Paulo F., E-mail: silvasf@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Barreto, Erika S.; Ribeiro, Isabela G.; Fraiz, Felipe C. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

    2013-07-01

    The IPR-R1 TRIGA MARK 1 reactor is an open pool type reactor, cooled light water. It is used for research activities, personnel training and radioisotopes production, in operation since 1960 at the Nuclear Technology Development Center - CDTN/CNEN. It operates at a maximum thermal power of 100 kW and usually, the fuel cooling is done by natural circulation. If necessary, an external auxiliary cooling system, with a shell-and-tube type heat exchanger, can be used to improve the water heat removal. As part of the ageing management program of the reactor, a nondestructive evaluation of their heat exchanger stainless steel tubes will be performed, in order to verify its integrity. The examinations will be performed using the eddy current test method, which allows the detection and characterization of structural discontinuities in the wall of the tubes, if existing. For this purpose, probes and reference standards were designed and manufactured at CDTN facilities and test procedures were established and validated. In this paper, a description of the proposed infrastructure as well as the test methodology to be used in the examinations are presented and discussed. (author)

  6. Prospective electrocardiogram gated coronary 320-row area detector computed tomography angiography using low tube current scanning with full reconstruction

    International Nuclear Information System (INIS)

    It is possible to obtain equivalent image quality and a lower radiation dose using low tube current scanning with full reconstruction as compared to usual tube current scanning with half reconstruction in a 320-row area detector computed tomography (ADCT) angiography. Of 589 patient underwent coronary CT angiography (CCTA), 11 patients with (RR-PQ) ≥1069 ms were enrolled. In those patients, low tube current (50% mA) scanning with full or half reconstruction were performed. As a control, 11 patients with matched pairs of tube voltage, BMI and heart rate who underwent usual scanning with half reconstruction (100% mA with half reconstruction) were selected. Standard deviation of the CT value (SD) was measured in aorta (Ao), left atrium (LA) and left ventricle (LV), and extended dose-length products (DLP.e) were calculated. Significant motion artifact was not observed in any patients. SD of 50% mA with half reconstruction, 50% mA with full reconstruction, and 100% mA with half reconstruction were 28.1±2.6, 20.3±1.9, 20.7±2.5 Hounsfield unit (HU) in Ao, 34.4±4.4, 24.9±2.8, 24.9±3.1 HU in LA, and 29.7±2.3, 21.7±1.9, 22.1±2.3 HU in LV, respectively. There were not significant differences between 50% mA with full reconstruction and 100% mA with half reconstruction, but there were significant differences between 50% mA with half reconstruction and 50% mA with full reconstruction in all sites. The DLP.e of 50% mA scanning (74.1±21.8 mGy·cm) was significantly lower than 100% mA scanning (161.9±28.9 mGy·cm). CCTA with lower radiation dose and equivalent image quality can be obtained by ADCT using 50% mA scanning with full reconstruction in patients with (RR-PQ) ≥1069 ms. (author)

  7. Overbeaming and overlapping of volume-scan CT with tube current modulation in a 320-detector row CT scanner

    International Nuclear Information System (INIS)

    The purpose of this study was to evaluate the performance of volume scan tube current modulation (VS-ATCM) with adaptive iterative dose reduction 3D (AIDR3D) technique in abdomen CT examinations. We scanned an elliptical cone-shaped phantom utilizing AIDR3D technique combined with VS-ATCM mode in a 320-detector row CT scanner. The image noise distributions with conventional filtered back-projction (FBP) technique and those with AIDR3D technique were compared. The radiation dose profile and tube current time product (mAs) in three noise levels of VS-ATCM modes were compared. The radiation beam profiles of five preset scan lengths were measured using Gafchromic film strips to assess the effects of overbeaming and everlapping. The results indicated that the image noises with AIDR3D technique was 13–74% lower than those in FBP technique. The mAs distributions can be a prediction for various abdominal sizes when undergoing a VS-ATCM mode scan. Patients can receive the radiation dose of overbeaming and overlapping during the VS-ATCM mode scans. - Highlights: • Noise reduction with AIDR3D in VS-ATCM is 13–74%. • We provide mAs prediction in VS-ATCM for all sizes. • We observe the effect of overbeaming and overlapping

  8. Contribution to perfecting eddy current testing of steam generator tubes of sodium cooled breeders: description of the Monacault loop for the study of sodium deposit influence

    International Nuclear Information System (INIS)

    In the event of sodium-water reaction in the steam generator of a sodium cooled breeder reactor, it is essential to be able to monitor the local loss of thickness of the tubes located in the reaction area. A method for monitoring the tubes by an eddy current probe is being developed for Super Phenix. The sodium deposits on the outer wall of the tubes, as well as their prolonged contact with high temperature sodium are likely to bring about a change in the signals picked up. A test loop, Monacault, has been built in order to clarify the importance of these parameters (effect of sodium deposits, reproducibility of the wetting at different temperatures). It includes three test cells containing the sample tubes having a total of 61 standard defects to be tested. The first results on the wetting of tubes are given and discussed

  9. High critical current density in powder-in-tube processed MgB2/Ta/Cu wire

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The magnetization of dense MgB2/Ta/Cu wires prepared by the powder-in-tube method is measured by a SQUID magnetometer. The results indicate that the critical temperature of MgB2/Ta/Cu is around 38.4 K with a sharp transition width of 0.6 K. The MgB2/Ta/Cu wire shows a strong flux pinning and the critical current density is higher than 105 A/cm2 (5 K, self-field) and 104 A/cm2 (20 K, 1 T). Also, the irreversibility field of the sample reaches 6.6 T at 5 K.

  10. Al current collector surface treatment and carbon nano tubes influences on Carbon / Carbon super-capacitors performances

    Energy Technology Data Exchange (ETDEWEB)

    Portet, C.; Taberna, P.L.; Simon, P. [Universite Paul Sabatier, CIRIMAT-LCMIE, 31 - Toulouse (France)

    2004-07-01

    Performances of 4 cm{sup 2} carbon/carbon super-capacitors cells using Al current collectors foils in organic electrolyte are presented; the improvement of electrode material has been investigated. In a first part, a surface treatment of the Al current collector is proposed in order to improve contact surface between the current collector and the active material leading to an internal resistance decrease. The process consists in an etching of the Al foil and is followed by a carbonaceous sol-gel deposit. Galvano-static cycling and Electrochemical Impedance Spectroscopy measurements of super-capacitors all assembled with treated Al foil were tested over 10,000 cycles: an ESR of 0.5 {omega} cm{sup 2} and a capacitance of 95 F g{sup -1} of activated carbon are obtained and performances remain stable during cycling. The second part is devoted to the study of Carbon Nano Tubes (CNTs) adding into the active material on the performances of super-capacitors. A content of 15% of CNTs appears to be the best composition; the ESR is 0.4 {omega} cm{sup 2} (20% lowered as compared to a cell using activated carbon based electrode) and the capacitance remain high 93 F g{sup -1} of carbonaceous active material. (authors)

  11. Counter-current flow in a vertical to horizontal tube with obstructions

    Energy Technology Data Exchange (ETDEWEB)

    Tye, P.; Matuszkiewicz, A.; Teyssedou, A. [Institut de Genie Nucleaire, Quebec (Canada)] [and others

    1995-09-01

    This paper presents experimental results on counter-current flow and flooding in an elbow between a vertical and a horizontal run. The experimental technique used allowed not only the flooding limit to be determined, but also the entire partial delivery region to be studied as well. The influence that various size orifices placed in the horizontal run have on both the delivered liquid flow rates and on the flooding limits is also examined. It is observed that both the flooding limits and the delivered liquid flow rates decrease with decreasing orifice size. Further, it is also observed that the mechanisms that govern the partial delivery of the liquid are significantly different when an orifice is present in the horizontal leg as compared to the case when no orifice is present.

  12. Phenomenological modeling of eddy current signals with a view to characterizing steam generator tube flaws; Modelisation phenomenologique des signaux courants de Foucault en vue de la caracterisation des defauts des tubes de generateurs de vapeur

    Energy Technology Data Exchange (ETDEWEB)

    La, R

    1997-12-31

    This work deals with the eddy current non-destructive test ing. Its long-term goal is to design an `inverse model` for evaluating the geometry an d the dimensions of steam generator tube flaws from eddy current signals. The approach we adopted requires the preliminary knowledge of a `forward model` that estimates the eddy current signal knowing the geometry and the dimensions of the flaws. A quasi-exhaustive study of the existing forward models showed their inadequacy to solve the inverse problem. Hence, we proposed to build a general forward model, appropriate to the inversion. Using a parametric approach, this model is phenomenological, i.e. it is based on observations made from results of a finite element code. For each position of the coil, the proposed forward model fist discretized the eddy current distribution into `tubes of current`. A parametric description of the shape of these tubes is given according the system constituted of the coil and the tubes of current as a `multi-transformer`, their current signal, can then be deduced. The model was validated in the case of an axisymmetric configuration. Comparisons with both analytical and numerical models showed very good agreements. Then, the proposed model was applied to a three-dimensional configuration. Comparisons with experimental results are sufficiently conclusive to validate the approach to the construction of the phenomenological model. However, before envisaging the inverse problem, the computation time, still too long, ought to be reduced and the parametric description needs to be generalized to other three-dimensional configurations. (author). 92 refs.

  13. 汽车自动变速器油的技术现状与发展趋势%Current Technology and Development Trends of Automatic Transmission Fluids

    Institute of Scientific and Technical Information of China (English)

    李茂生; 杜群贵; 贾继欣

    2014-01-01

    The types,characteristics and developing direction of vehicle automatic transmission,and the technical re-quirement,current technological state and development trend of automatic transmission fluids (ATF/CVTF ) were de-scribed.The tribological characteristics and evaluation method of ATF/CVTF were introduced.The development and appli-cation of new automatic transmission fluids and its corresponding evaluation test methods of physical and chemical proper-ties,friction characteristics and wear state,the development of the specifications and standard of automatic transmission flu-ids are key common technologies for development of automatic transmission.%论述汽车自动变速器(AT、CVT)的类型、特点及发展方向,以及与其配套的变速器油(ATF、CVTF)的技术现状和发展趋势,介绍ATF/CVTF的摩擦学特性及其评价方法。开发和应用新型自动变速器油及其相应的摩擦特性测试方法、磨损状态评定手段和油品理化性能测试方法及台架试验方法,制定自动变速器油的规格标准,是促进自动变速器发展的关键共性技术。

  14. The Design on Automatic Detection System of Ventilating and Leaking of Disposable Infusion Tube Based on PLC%基于PLC的一次性输液管通、漏气自动检测系统设计

    Institute of Scientific and Technical Information of China (English)

    夏链; 李福根; 韩春明

    2011-01-01

    一次性输液管是医疗行业不可或缺用来给病人进行静脉输液的器件.对其通气和漏气质量检测是其生产过程中极为重要的环节.通过调研发现,国内主要采用手工进行检测,自动检测装置很少,生产效率低.本文设计了一种基于PLC控制的自动检测装置.经过试验,能够实现自动检测,与手工检测相比,大大提高了工作效率和检测质量的可靠性.%Disposable infusion tube is essential for the medical industry,which is the device of intravenous infusion for the patient. The quality detecting of ventilating and leaking is an important part of the Production process. Through research, it has been found that most detecting is manual in our country and automatic detection devices are few,thus the production efficiency is low. A kind of automatic detection device based on PLC controlled has been designed. After testing, the results show that it can achieve automatic detection. Compared with the manual detecting,the efficiency and reliability of quality detecting greatly improve.

  15. Effective dose and organ doses estimation taking tube current modulation into account with a commercial software package

    International Nuclear Information System (INIS)

    To evaluate the effect of including tube current modulation (TCM) versus using the average mAs in estimating organ and effective dose (E) using commercial software. Forty adult patients (24 females, 16 males) with normal BMI underwent chest/abdomen computed tomography (CT) performed with TCM at 120 kVp, reference mAs of 110 (chest) and 200 (abdomen). Doses to fully irradiated organs (breasts, lungs, stomach, liver and ovaries) and E were calculated using two versions of a dosimetry software: v.2.0, which uses the average mAs, and v.2.2, which accounts for TCM by implementing a gender-specific mAs profile. Student's t-test was used to assess statistically significant differences between organ doses calculated with the two versions. A statistically significant difference (p < 0.001) was found for E on chest and abdomen CT, with E being lower by 4.2 % when TCM is considered. Similarly, organ doses were also significantly lower (p < 0.001): 13.7 % for breasts, 7.3 % for lungs, 9.1 % for the liver and 8.5 % for the stomach. Only the dose to the ovaries was higher with TCM (11.5 %). When TCM is used, for the stylized phantom, the doses to lungs, breasts, stomach and liver decreased while the dose to the ovaries increased. (orig.)

  16. Effective dose and organ doses estimation taking tube current modulation into account with a commercial software package

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Rendon, X. [KU Leuven, Department of Imaging and Pathology, Division of Medical Physics and Quality Assessment, Herestraat 49, box 7003, Leuven (Belgium); Bosmans, H.; Zanca, F. [KU Leuven, Department of Imaging and Pathology, Division of Medical Physics and Quality Assessment, Herestraat 49, box 7003, Leuven (Belgium); University Hospitals Leuven, Department of Radiology, Leuven (Belgium); Oyen, R. [University Hospitals Leuven, Department of Radiology, Leuven (Belgium)

    2015-07-15

    To evaluate the effect of including tube current modulation (TCM) versus using the average mAs in estimating organ and effective dose (E) using commercial software. Forty adult patients (24 females, 16 males) with normal BMI underwent chest/abdomen computed tomography (CT) performed with TCM at 120 kVp, reference mAs of 110 (chest) and 200 (abdomen). Doses to fully irradiated organs (breasts, lungs, stomach, liver and ovaries) and E were calculated using two versions of a dosimetry software: v.2.0, which uses the average mAs, and v.2.2, which accounts for TCM by implementing a gender-specific mAs profile. Student's t-test was used to assess statistically significant differences between organ doses calculated with the two versions. A statistically significant difference (p < 0.001) was found for E on chest and abdomen CT, with E being lower by 4.2 % when TCM is considered. Similarly, organ doses were also significantly lower (p < 0.001): 13.7 % for breasts, 7.3 % for lungs, 9.1 % for the liver and 8.5 % for the stomach. Only the dose to the ovaries was higher with TCM (11.5 %). When TCM is used, for the stylized phantom, the doses to lungs, breasts, stomach and liver decreased while the dose to the ovaries increased. (orig.)

  17. Phase Distinction in Eddy Current Testing for Steel Tubes%钢管涡流探伤中缺陷信号的相位分辨

    Institute of Scientific and Technical Information of China (English)

    林俊明; 赖传理; 任吉林

    2011-01-01

    In the eddy current testing for steel tubes, the problem that the phases of defect signals could not be distinguished existed when the magnetization intensity of the tubes was oversaturated. Theoretical analysis and experimental results showed that there were two testing mechanisms in the eddy current testing for steel tubes: eddy current effect and magnetic flux leakage effect. When the magnetization intensity of the tubes was oversaturated, the magnetic flux leakage effect was stronger than eddy current effect and was dominant, which made the phases of defect signals could not be distinguished.%钢管在涡流探伤中,过饱和磁化时会出现内外壁缺陷信号相位无法分辨的问题.理论分析及试验表明,钢管涡流探伤存在涡流效应及漏磁效应两种机理,钢管过饱和磁化时由于漏磁效应强于涡流效应,使得缺陷信号相位无法分辨.为使内外壁缺陷信号的相位正常区分,应控制钢管磁化至饱和磁化强度的60 %~70%.

  18. Application of Automatic Submerged -arc Welding in Girth Welding of Arch Rib of Tube Arch%埋弧自动焊在钢管拱拱肋环焊缝中的应用

    Institute of Scientific and Technical Information of China (English)

    宇文德成; 张丽惠

    2011-01-01

    Research purposes: According to the structural characteristics of the arch rib of the steel tube of polygonal line (arc shape) , this paper tries to find out the negative factors which affect the welding position, speed changes and structural mass balance when joining the segment of arch rib into the polygonal line (Arc shape) during automatic submerged - arc welding, and offers the solution to the problem with kinematic analysis and calculation for making the processing of arch rib of steel tube in workshop fulfilled by submerged - arc welding.Research conclusions:Based on the theoretical analysis and according to the actual production process, the negative factors were overcome by determining the reasonable support location of roller and properly configuring weight equalizer. Based on it, a method to do girth welding of polygonal line tube with submerged - arc welding was found. With this method, the 100% of automatic welding of girth joint in factory workshop can be realized, which is up to 90% of the full - bridge tube girth joint with features of less welding defects, stable welding quality and improving welding efficiency.%研究目的:根据钢管拱折线(弧形)拱肋的结构特点,找出将拱肋节段对接成折线(弧形)时,影响采用埋弧自动焊时焊点位置、速度变化和结构质量平衡的不利因素.并通过运动学分析与计算,提出解决问题的方法.使钢管拱拱肋厂内加工全部实现采用埋弧自动焊工艺.研究结论:根据理论分析,在实际生产过程中,采取确定滚轮合理的支撑位置及适当配置平衡重物这两种措施,克服了不利因素,摸索出了一套在滚轮架上用自动埋弧焊工艺焊接折线管对接环焊缝的方法,实现了工厂内加工环焊缝100%的自动化焊接,占全桥所有管对接环焊缝的90%以上,焊缝缺陷频率低、质量稳定、提高了工效.

  19. Evaluation of critical current density and residual resistance ratio limits in powder in tube Nb3Sn conductors

    Science.gov (United States)

    Segal, Christopher; Tarantini, Chiara; Hawn Sung, Zu; Lee, Peter J.; Sailer, Bernd; Thoener, Manfred; Schlenga, Klaus; Ballarino, Amalia; Bottura, Luca; Bordini, Bernardo; Scheuerlein, Christian; Larbalestier, David C.

    2016-08-01

    High critical current density (J c) Nb3Sn A15 multifilamentary wires require a large volume fraction of small grain (SG), superconducting A15 phase, as well as Cu stabilizer with high Residual Resistance Ratio (RRR) to provide electromagnetic stabilization and protection. In powder-in-tube (PIT) wires the unreacted Nb7.5 wt%Ta outer layer of the tubular filaments acts as a diffusion barrier and protects the interfilamentary Cu stabilizer from Sn contamination. A high RRR requirement generally imposes a restricted A15 reaction heat treatment to prevent localized full reaction of the filament that could allow Sn to reach the Cu. In this study we investigate recent high quality PIT wires that achieve a J c (12 T, 4.2 K) up to ∼2500 A mm‑2 and find that the minimum diffusion barrier thickness decreases as the filament aspect ratio increases from ∼1 in the inner rings of filaments to 1.3 in the outer filament rings. We found that just 2–3 diffusion barrier breaches can degrade RRR from 300 to 150 or less. Using progressive etching of the Cu we also found that the RRR degradation is localized near the external filaments where deformation is highest. Consequently minimizing filament distortion during strand fabrication is important for reducing RRR degradation. The additional challenge of developing the highest possible J c must be addressed by forming the maximum fraction of high J c SG A15 and minimizing low J c large-grain (LG) A15 morphologies. In one wire we found that 15% of the filaments had a significantly enhanced SG/LG A15 ratio and no residual A15 in the core, a feature that opens a path to substantial J c improvement.

  20. Gastric tubes and airway management in patients at risk of aspiration: history, current concepts, and proposal of an algorithm.

    Science.gov (United States)

    Salem, M Ramez; Khorasani, Arjang; Saatee, Siavosh; Crystal, George J; El-Orbany, Mohammad

    2014-03-01

    Rapid sequence induction and intubation (RSII) and awake tracheal intubation are commonly used anesthetic techniques in patients at risk of pulmonary aspiration of gastric or esophageal contents. Some of these patients may have a gastric tube (GT) placed preoperatively. Currently, there are no guidelines regarding which patient should have a GT placed before anesthetic induction. Furthermore, clinicians are not in agreement as to whether to keep a GT in situ, or to partially or completely withdraw it before anesthetic induction. In this review we provide a historical perspective of the use of GTs during anesthetic induction in patients at risk of pulmonary aspiration. Before the introduction of cricoid pressure (CP) in 1961, various techniques were used including RSII combined with a head-up tilt. Sellick initially recommended the withdrawal of the GT before anesthetic induction. He hypothesized that a GT increases the risk of regurgitation and interferes with the compression of the upper esophagus during CP. He later modified his view and emphasized the safety of CP in the presence of a GT. Despite subsequent studies supporting the effectiveness of CP in occluding the esophagus around a GT, Sellick's early view has been perpetuated by investigators who recommend partial or complete withdrawal of the GT. On the basis of available information, we have formulated an algorithm for airway management in patients at risk of aspiration of gastric or esophageal contents. The approach in an individual patient depends on: the procedure; type and severity of the underlying pathology; state of consciousness; likelihood of difficult airway; whether or not the GT is in place; contraindications to the use of RSII or CP. The algorithm calls for the preanesthetic use of a large-bore GT to remove undigested food particles and awake intubation in patients with achalasia, and emptying the pouch by external pressure and avoidance of a GT in patients with Zenker diverticulum. It also

  1. Development of a system for monitoring and diagnosis of steam generator tubes using artificial intelligence techniques on Eddy Current Test signals

    International Nuclear Information System (INIS)

    New classification and feature extraction methods for steam generator tube defects are being developed by IPEN/CNEN-SP in cooperation with UTK to improve a monitoring and diagnosis system for classification and characterization of steam generator tube defects using Eddy Current Testing (ECT) signals. The first methodology being developed uses a set of feature extraction methods applied to different tube defect type ECT signals and each obtained feature vector is projected into a bi-dimensional map obtained by a Self-Organizing Map neural network. This methodology allows an optimal feature extraction method selection for the defect type classification. Other approach is being developed using tubes with different manufactured defect types which are tested using MIZ-17ET equipment with 4 sets of probes (two different diameter). A fuzzy inference system will be used to build a knowledge base for these defects. These methodology and algorithms will be integrated into an automated diagnosis system being developed with UTK, which is designed to read both on-line acquired data, as well as stored data files. These commercial software tools are the ones usually utilized in nuclear power plants. (author)

  2. Technical Note: Phantom study to evaluate the dose and image quality effects of a computed tomography organ-based tube current modulation technique

    Energy Technology Data Exchange (ETDEWEB)

    Gandhi, Diksha; Schmidt, Taly Gilat, E-mail: taly.gilat-schmidt@marquette.edu [Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin 53201 (United States); Crotty, Dominic J.; Stevens, Grant M. [GE Healthcare, Waukesha, Wisconsin 53188 (United States)

    2015-11-15

    Purpose: This technical note quantifies the dose and image quality performance of a clinically available organ-dose-based tube current modulation (ODM) technique, using experimental and simulation phantom studies. The investigated ODM implementation reduces the tube current for the anterior source positions, without increasing current for posterior positions, although such an approach was also evaluated for comparison. Methods: Axial CT scans at 120 kV were performed on head and chest phantoms on an ODM-equipped scanner (Optima CT660, GE Healthcare, Chalfont St. Giles, England). Dosimeters quantified dose to breast, lung, heart, spine, eye lens, and brain regions for ODM and 3D-modulation (SmartmA) settings. Monte Carlo simulations, validated with experimental data, were performed on 28 voxelized head phantoms and 10 chest phantoms to quantify organ dose and noise standard deviation. The dose and noise effects of increasing the posterior tube current were also investigated. Results: ODM reduced the dose for all experimental dosimeters with respect to SmartmA, with average dose reductions across dosimeters of 31% (breast), 21% (lung), 24% (heart), 6% (spine), 19% (eye lens), and 11% (brain), with similar results for the simulation validation study. In the phantom library study, the average dose reduction across all phantoms was 34% (breast), 20% (lung), 8% (spine), 20% (eye lens), and 8% (brain). ODM increased the noise standard deviation in reconstructed images by 6%–20%, with generally greater noise increases in anterior regions. Increasing the posterior tube current provided similar dose reduction as ODM for breast and eye lens, increased dose to the spine, with noise effects ranging from 2% noise reduction to 16% noise increase. At noise equal to SmartmA, ODM increased the estimated effective dose by 4% and 8% for chest and head scans, respectively. Increasing the posterior tube current further increased the effective dose by 15% (chest) and 18% (head

  3. 粉状炸药大产能自动装药机研究%Analysis on Automatic Charging Machine of Plastic Tube Powdery Explosive of Large Capacity

    Institute of Scientific and Technical Information of China (English)

    白文忠; 任卫东; 刘静; 齐印川; 王木申

    2014-01-01

    Although its flowing disperse is good of powdery explosive, but it cannot finish the small cartridge charging just by its own gravity. For the purpose of rapid reload, the core technology of this research is to increase the flowing disperse during bulking of powdery explosive by using the theory of vibration of deflector and vibration punning. Besides, it cannot satisfy the charge density and the weight requirement of powdery explosive of loading in the medicine tube, it also need to vibration energy transfer to punning powdery explosive, eventually get the charge density conforms to the technological requirement. By using this way to realize propellant intrinsically safe, vibration propellant abolish the single tube driving structure in addition, and further simplification of the equipment, in theory, it can unlimitedly increase propellant tube number, conducive to productivity improvement.%粉状炸药的流散性较好,但不能仅仅依靠自身的重力完成小药卷装药。核心就是利用“振动导流、振动夯实”的原理,提高粉状炸药灌装时的流散性,而达到快速装填的目的。此外,装入药管内的粉状药,仅靠自流堆积填满,是无法满足装药密度及重量要求,也需要振动传递的能量来“夯实”药粉,最终获得符合工艺要求的装药密度。采用该途径来完成炸药灌装作业,彻底消除了摩擦生热的安全隐患,实现了装药本质安全,此外,震动装药取消了单管驱动结构,设备更加简化,理论上可以无限制增加装药管数量,有利于产能提高。

  4. Eddy Current and Ultrasonic IRIS Signal Characteristics of Reboiler Tube by Using STS 316L Calibration Specimen

    International Nuclear Information System (INIS)

    In this study, a field applicability of reboiler tube was evaluated by comparing ECT signal with IRIS signal about wall loss rate and remaining wall thickness using worked austenite STS 316L ASME standard calibration tube. In the case of wall-loss rate, as a result, tolerance about flat bottom hole and 10% O D groove(ECT), 80% defect and 10% O D groove(IRIS) occurred up to ±15%. In the case of remaining wall thickness, ECT was satisfied with the both tolerance, but tolerance about 80% defect occurred up to ±15% in IRIS. Therefore, if the IRIS is performed for interpretation of non-relevant indication and measurement of wall-loss rate after ECT, reliability is supposed to be improved

  5. Dose equations for shift-variant CT acquisition modes using variable pitch, tube current, and aperture, and the meaning of their associated CTDIvol

    International Nuclear Information System (INIS)

    Purpose: With the increasing clinical use of shift-variant CT protocols involving tube current modulation (TCM), variable pitch or pitch modulation (PM), and variable aperture a(t), the interpretation of the scanner-reported CTDIvol is called into question. This was addressed for TCM in their previous paper published by Dixon and Boone [Med. Phys. 40, 111920 (14pp.) (2013)] and is extended to PM and concurrent TCM/PM as well as variable aperture in this work. Methods: Rigorous convolution equations are derived to describe the accumulated dose distributions for TCM, PM, and concurrent TCM/PM. A comparison with scanner-reported CTDIvol formulae clearly identifies the source of their differences with the traditional CTDIvol. Dose distribution simulations using the convolution are provided for a variety of TCM and PM scenarios including a helical shuttle used for perfusion studies (as well as constant mA)—all having the same scanner-reported CTDIvol. These new convolution simulations for TCM are validated by comparison with their previous discrete summations. Results: These equations show that PM is equivalent to TCM if the pitch variation p(z) is proportional to 1/i(z), where i(z) is the local tube current. The simulations show that the local dose at z depends only weakly on the local tube current i(z) or local pitch p(z) due to scatter from all other locations along z, and that the “local CTDIvol(z)” or “CTDIvol per slice” do not represent a local dose but rather only a relative i(z) or p(z). The CTDI-paradigm does not apply to shift-variant techniques and the scanner-reported CTDIvol for the same lacks physical significance and relevance. Conclusions: While the traditional CTDIvol at constant tube current and pitch conveys useful information (the peak dose at the center of the scan length), CTDIvol for shift-variant techniques (TCM or PM) conveys no useful information about the associated dose distribution it purportedly represents. On the other hand, the

  6. Development and validation of a simulation tool dedicated to eddy current non destructive testing of tubes; Developpement d'un modele electromagnetique 3D pour la simulation du controle par Courants de Foucault de tubes en fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Reboud, Ch

    2006-09-15

    Eddy current testing (ECT) technique is widely used in industrial fields such as iron and steel industry. Dedicated simulation tools provide a great assistance for the optimisation of ECT processes. CEA and the Vallourec Research Center have collaborated in order to develop a simulation tool of ECT of tubes. The volume integral method has been chosen for the resolution of Maxwell equations in a stratified medium, in order to get accurate results with a computation time short enough to carry out optimisation or inversion procedures. A fast model has been developed for the simulation of ECT of non magnetic tubes using specific external probes. New flaw geometries have been modelled: holes and notches with flat bottom. Validations of the developments, which have been integrated to the CIVA platform, have been carried out using experimental data recorded in laboratory conditions and in. industrial conditions, successively. The integral equations derived are solved using the Galerkin variant of the method of moments with pulse functions as projection functions. In order to overcome some memory limitations, other projection functions have been considered. A new discretization scheme based on non-uniform B-Splines of degree 1 or 2 has been implemented, which constitutes an original contribution to the existing literature. The decrease of the mesh size needed to get a given accuracy on the result may lead to the simulation of more complex ECT configurations. (author)

  7. Enantioseparation of (DL)-tryptophan by spiral tube assembly counter-current chromatography and evaluation of mass transfer rate for enantiomers.

    Science.gov (United States)

    Tong, Shengqiang; Ito, Yoichiro; Ma, Ying

    2014-12-29

    Spiral tube assembly counter-current chromatography was successfully applied in enantioseparation of dl-tryptophan using bovine serum albumin as chiral selector. An improved biphasic aqueous-aqueous solvent system 12.0% (w/w) polyethyleneglycol 8000-9.0% (w/w) dibasic potassium phosphate-0.1% ammonia-78.9% water was used as the solvent system for counter-current chromatography, in which bovine serum albumin was predominantly distributed in the lower phase of the two-phase aqueous system. The aqueous-aqueous solvent system gave a very high enantioselectivity for d- and l-tryptophan at α=2.605 along with distribution ratio DD=1.200 and DL=0.461. High peak resolution was obtained for enantioseparation of 2.0mg of dl-tryptophan by spiral tube assembly counter-current chromatography under room temperature. It was found that 0.1% ammonia added in the aqueous-aqueous solvent system greatly improved the enantioseparations. An unusual extremely broad peak for l-tryptophan was observed during enantioseparations. In order to give an explanation, mass transfer rates of d- and l-enantiomers through the interface between the two phases were measured. It was found that l-tryptophan showed lower mass transfer rate than d-tryptophan. Further discussions were proposed for possible reasons for mass transfer rate difference between the enantiomers.

  8. Effects of stoichiometric variation and cooling rate on the phase formation and critical current density of Bi-2223 powder-in-tube tapes made from aerosol precursor

    International Nuclear Information System (INIS)

    Powder-in-tube Bi-2223 is currently the most promising high-temperature superconductor that can be fabricated in long lengths by industrial processes, and is likely to be used as the conductor component in first-generation applications. Intensive investigations of these conductors have revealed that the critical current density of fully processed tapes is influenced by a large number of processing parameters. Among these are the thermomechanical processing schedule and the extent of Bi-2223 phase conversion. These parameters are, in turn, affected by the precursor stoichiometry. In this study, powder precursors with varying Cu content were prepared using an aerosol pyrolysis technique, and powder-in-tube conductors were fabricated using these precursors. Both fast and slow cooling rates were employed during thermomechanical processing, and different treatment schedules are correlated to the critical current density. The results indicate that the effect of excess Cu on Jc is minor compared to the large Jc enhancements obtained by employing one or more slow-cooling steps in the thermomechanical processing schedule. (author)

  9. 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.

  10. 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.

  11. Comparison of standardized uptake values measured on {sup 18}F-NaF PET/CT scans using three different tube current intensities

    Energy Technology Data Exchange (ETDEWEB)

    Valadares, Agnes Araujo; Woellner, Eduardo Bechtloff; Sapienza, Marcelo Tatit; Buchpiguel, Carlos Alberto, E-mail: agnesvaladares@me.com [Universidade de Sao Paulo (HC/FMUSP), Sao Paulo, SP (Brazil). Fac. de Medicina. Hospital das Clinicas; Duarte, Paulo Schiavom; Coura-Filho, George Barberio [Instituto do Cancer do Estado de Sao Paulo Octavio Frias de Oliveira (ICESP), Sao Paulo, SP (Brazil)

    2015-01-15

    Objective: to analyze standardized uptake values (SUVs) using three different tube current intensities for attenuation correction on {sup 18}FNaF PET/CT scans. Materials and methods: a total of 254 {sup 18}F-NaF PET/CT studies were analyzed using 10, 20 and 30 mAs. The SUVs were calculated in volumes of interest (VOIs) drawn on three skeletal regions, namely, right proximal humeral diaphysis (RH), right proximal femoral diaphysis (RF), and first lumbar vertebra (LV1) in a total of 712 VOIs. The analyses covered 675 regions classified as normal (236 RH, 232 RF, and 207 LV1). Results: mean SUV for each skeletal region was 3.8, 5.4 and 14.4 for RH, RF, and LV1, respectively. As the studies were grouped according to mAs value, the mean SUV values were 3.8, 3.9 and 3.7 for 10, 20 and 30 mAs, respectively, in the RH region; 5.4, 5.5 and 5.4 for 10, 20 and 30 mAs, respectively, in the RF region; 13.8, 14.9 and 14.5 for 10, 20 and 30 mAs, respectively, in the LV1 region. Conclusion: the three tube current values yielded similar results for SUV calculation. (author)

  12. Evaluation of automated attenuation-based tube current adaptation for coronary calcium scoring in MDCT in a cohort of 262 patients

    International Nuclear Information System (INIS)

    The aim of our study was to evaluate attenuation-based tube current adaptation in coronary calcium scoring using ECG-gated multi-detector-row CT (MDCT). A total of 262 patients underwent non-enhanced cardiac MDCT. Group 1 was scanned using a standard protocol with 120 kV and 150 mAseff. Groups 2-4 were scanned using an attenuation-based dose-adaptation template (CARE Dose) with different effective reference mAs settings (150, 180, 210 mAseff). Body-mass index (BMI) and CT-dose index values were calculated for each patient. Image noise and subjective image quality were assessed. Regression analysis was performed, and the variation coefficient of image noise was determined. Compared to the standard scan protocol a dose reduction of 31.1% for group 2 and 20.1% for group 3 was observed. Measurement variation of image noise was smaller for the attenuation-based dose adaptation protocols (group 2-4) (16.2-17.1%) compared to the standard scan protocol (32.3%). Regression analysis of groups 2-4 showed better correlation with improved dose usage based on BMI (all P ≤ 0.001). Median image quality was ''excellent'' in groups 2-4 and ''good'' in group 1. Automated attenuation-based tube current adaptation in coronary calcium scoring is technically feasible, can decrease patient dose, and reduces variation in image noise as a sign of improved dose usage. (orig.)

  13. Comparison of standardized uptake values measured on 18F-NaF PET/CT scans using three different tube current intensities

    Directory of Open Access Journals (Sweden)

    Agnes Araujo Valadares

    2015-02-01

    Full Text Available Objective: To analyze standardized uptake values (SUVs using three different tube current intensities for attenuation correction on 18FNaF PET/CT scans. Materials and Methods: A total of 254 18F-NaF PET/CT studies were analyzed using 10, 20 and 30 mAs. The SUVs were calculated in volumes of interest (VOIs drawn on three skeletal regions, namely, right proximal humeral diaphysis (RH, right proximal femoral diaphysis (RF, and first lumbar vertebra (LV1 in a total of 712 VOIs. The analyses covered 675 regions classified as normal (236 RH, 232 RF, and 207 LV1. Results: Mean SUV for each skeletal region was 3.8, 5.4 and 14.4 for RH, RF, and LV1, respectively. As the studies were grouped according to mAs value, the mean SUV values were 3.8, 3.9 and 3.7 for 10, 20 and 30 mAs, respectively, in the RH region; 5.4, 5.5 and 5.4 for 10, 20 and 30 mAs, respectively, in the RF region; 13.8, 14.9 and 14.5 for 10, 20 and 30 mAs, respectively, in the LV1 region. Conclusion: The three tube current values yielded similar results for SUV calculation.

  14. Dynamic tube/support interaction in heat exchanger tubes

    Energy Technology Data Exchange (ETDEWEB)

    Chen, S.S.

    1991-01-01

    The supports for heat exchanger tubes are usually plates with drilled holes; other types of supports also have been used. To facilitate manufacture and to allow for thermal expansion of the tubes, small clearances are used between tubes and tube supports. The dynamics of tube/support interaction in heat exchangers is fairly complicated. Understanding tube dynamics and its effects is important for heat exchangers. This paper summarizes the current state of the art on this subject and to identify future research needs. Specifically, the following topics are discussed: dynamics of loosely supported tubes, tube/support gap dynamics, tube response in flow, tube damage and wear, design considerations, and future research needs. 55 refs., 1 fig.

  15. The effect of wall friction on the current-sheet speed of a magnetically driven shock tube

    DEFF Research Database (Denmark)

    Chang, C.T.

    1971-01-01

    The effect of wall friction on the current-sheet speed is examined by taking some plausible forms of the friction into consideration. The analysis shows that the current-sheet always attains a steady state regardless of the types of friction concerned. It further shows that the experimentally...

  16. Automatic sequences

    CERN Document Server

    Haeseler, Friedrich

    2003-01-01

    Automatic sequences are sequences which are produced by a finite automaton. Although they are not random they may look as being random. They are complicated, in the sense of not being not ultimately periodic, they may look rather complicated, in the sense that it may not be easy to name the rule by which the sequence is generated, however there exists a rule which generates the sequence. The concept automatic sequences has special applications in algebra, number theory, finite automata and formal languages, combinatorics on words. The text deals with different aspects of automatic sequences, in particular:· a general introduction to automatic sequences· the basic (combinatorial) properties of automatic sequences· the algebraic approach to automatic sequences· geometric objects related to automatic sequences.

  17. Design of Automatic Welding Machine for Tube Plate Ring Weld of Tube Type Heat Exchanger and Welding Torch Orientation Simulation%管板式换热器管板环形焊缝自动焊机设计及焊枪定位仿真

    Institute of Scientific and Technical Information of China (English)

    徐向前; 周好斌; 王佳佳

    2015-01-01

    A simple, fast and precise positioning tube plate automatic welding machine was designed,according to the welding seam inaccurate positioning, low welding quality and efficiency in the tube plate seam welding of the tube plate exchanger during the welding process. The key of the welding machine is the localization and movement of the welding machine. The welding head is fixed on the gantry structure, and the stepping motor is used to drive the gantry structure and then the welding head's movement of two degrees of freedom is realized. The positioning of the welding head is realized by using CCD image processing. The design of the control system is completed based on C8051F020 MCU, and the human-computer interaction system includes the liquid crystal display and soft membrane 4 ×4 keyboard. Simulation by Matlab software, the center coordinates and radius of the pipe port circle can be obtained and welding head position can be achieved.%针对现有管板换热器管板环焊缝焊接过程中, 管板环焊缝定位不准确、 焊接质量和效率较低等问题, 设计了一种简单、 快捷、 定位精确的管板自动焊机. 焊接机头定位与移动是管板焊接的关键技术. 焊接机头固定在龙门架结构上, 采用步进电机驱动龙门架, 实现两自由度的运动; 利用CCD图像处理实现焊接机头的定位. C8051F020单片机作为主控芯片完成控制系统的设计, 液晶显示屏和4×4按键实现参数显示和设置. 通过Matlab软件仿真, 可获得钢管端口圆的半径和圆心坐标, 能够实现焊接机头定位.

  18. 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.

  19. Characterization and implementation of OSL dosimeters for use in evaluating the efficacy of organ-based tube current modulation for CT scans of the face and orbits

    Energy Technology Data Exchange (ETDEWEB)

    Marsh, R. M.; Silosky, M., E-mail: michael.silosky@ucdenver.edu [Department of Radiology, University of Colorado School of Medicine, Aurora, Colorado 80045 (United States)

    2015-04-15

    Purpose: The purpose of this work was to characterize commercially available optically stimulated luminescent (OSL) dosimeters for general clinical applications and apply the results to the development of a method to evaluate the efficacy of a vendor-specific organ-based tube current modulation application for both phantom and clinical computed tomography (CT) scans of the face and orbits. Methods: This study consisted of three components: (1) thorough characterization of the dosimeters for CT scans in phantom, including evaluations of depletion, fading, angular dependence, and conversion from counts to absorbed dose; (2) evaluation of the efficacy of using plastic glasses to position the dosimeters over the eyes in both phantom and clinical studies; and (3) preliminary dosimetry measurements made using organ-based tube current modulation in computed tomography dose index (CTDI) and anthropomorphic phantom studies. Results: (1) Depletion effects were found to have a linear relationship with the output of the OSL dosimeters (R{sup 2} = 0.96). Fading was found to affect dosimeter readings during the first two hours following exposure but had no effect during the remaining 60-h period observed. No significant angular dependence was observed for the exposure conditions used in this study (with p-values ranging from 0.9 to 0.26 for all t-tests). Dosimeter counts varied linearly with absorbed dose when measured in the center and 12 o’clock positions of the CTDI phantoms. These linear models of counts versus absorbed dose had overlapping 95% confidence intervals for the intercepts but not for the slopes. (2) When dosimeters were positioned using safety glasses, there was no adverse effect on image quality, and there was no statistically significant difference between this placement and placement of the dosimeters directly on the eyes of the phantom (p = 0.24). (3) When using organ-based tube current modulation, the dose to the lens of the eye was reduced between 19% and

  20. A database for estimating organ dose for coronary angiography and brain perfusion CT scans for arbitrary spectra and angular tube current modulation

    International Nuclear Information System (INIS)

    Purpose: The purpose of this study was to develop a database for estimating organ dose in a voxelized patient model for coronary angiography and brain perfusion CT acquisitions with any spectra and angular tube current modulation setting. The database enables organ dose estimation for existing and novel acquisition techniques without requiring Monte Carlo simulations. Methods: The study simulated transport of monoenergetic photons between 5 and 150 keV for 1000 projections over 360° through anthropomorphic voxelized female chest and head (0° and 30° tilt) phantoms and standard head and body CTDI dosimetry cylinders. The simulations resulted in tables of normalized dose deposition for several radiosensitive organs quantifying the organ dose per emitted photon for each incident photon energy and projection angle for coronary angiography and brain perfusion acquisitions. The values in a table can be multiplied by an incident spectrum and number of photons at each projection angle and then summed across all energies and angles to estimate total organ dose. Scanner-specific organ dose may be approximated by normalizing the database-estimated organ dose by the database-estimated CTDIvol and multiplying by a physical CTDIvol measurement. Two examples are provided demonstrating how to use the tables to estimate relative organ dose. In the first, the change in breast and lung dose during coronary angiography CT scans is calculated for reduced kVp, angular tube current modulation, and partial angle scanning protocols relative to a reference protocol. In the second example, the change in dose to the eye lens is calculated for a brain perfusion CT acquisition in which the gantry is tilted 30° relative to a nontilted scan. Results: Our database provides tables of normalized dose deposition for several radiosensitive organs irradiated during coronary angiography and brain perfusion CT scans. Validation results indicate total organ doses calculated using our database are

  1. A database for estimating organ dose for coronary angiography and brain perfusion CT scans for arbitrary spectra and angular tube current modulation

    Energy Technology Data Exchange (ETDEWEB)

    Rupcich, Franco; Badal, Andreu; Kyprianou, Iacovos; Schmidt, Taly Gilat [Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin 53233 (United States); Division of Imaging and Applied Mathematics (OSEL/CDRH), US Food and Drug Administration, Silver Spring, Maryland 20905 (United States); Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin 53233 (United States)

    2012-09-15

    Purpose: The purpose of this study was to develop a database for estimating organ dose in a voxelized patient model for coronary angiography and brain perfusion CT acquisitions with any spectra and angular tube current modulation setting. The database enables organ dose estimation for existing and novel acquisition techniques without requiring Monte Carlo simulations. Methods: The study simulated transport of monoenergetic photons between 5 and 150 keV for 1000 projections over 360 Degree-Sign through anthropomorphic voxelized female chest and head (0 Degree-Sign and 30 Degree-Sign tilt) phantoms and standard head and body CTDI dosimetry cylinders. The simulations resulted in tables of normalized dose deposition for several radiosensitive organs quantifying the organ dose per emitted photon for each incident photon energy and projection angle for coronary angiography and brain perfusion acquisitions. The values in a table can be multiplied by an incident spectrum and number of photons at each projection angle and then summed across all energies and angles to estimate total organ dose. Scanner-specific organ dose may be approximated by normalizing the database-estimated organ dose by the database-estimated CTDI{sub vol} and multiplying by a physical CTDI{sub vol} measurement. Two examples are provided demonstrating how to use the tables to estimate relative organ dose. In the first, the change in breast and lung dose during coronary angiography CT scans is calculated for reduced kVp, angular tube current modulation, and partial angle scanning protocols relative to a reference protocol. In the second example, the change in dose to the eye lens is calculated for a brain perfusion CT acquisition in which the gantry is tilted 30 Degree-Sign relative to a nontilted scan. Results: Our database provides tables of normalized dose deposition for several radiosensitive organs irradiated during coronary angiography and brain perfusion CT scans. Validation results indicate

  2. Evaluation of automated attenuation-based tube current adaptation for coronary calcium scoring in MDCT in a cohort of 262 patients

    Energy Technology Data Exchange (ETDEWEB)

    Muehlenbruch, Georg; Hohl, Christian; Das, Marco; Wildberger, Joachim E.; Thomas, Christoph; Guenther, Rolf W. [University Hospital (RWTH) Aachen, Department of Diagnostic Radiology, Aachen (Germany); Suess, Christoph; Klotz, Ernst; Flohr, Thomas [Siemens Medical Solutions, Computed Tomography, Forchheim (Germany); Koos, Ralf [University Hospital (RWTH) Aachen, Department of Cardiology, Aachen (Germany); Mahnken, Andreas H. [RWTH-Aachen University, Applied Medical Engineering, Helmholtz Institute, Aachen (Germany)

    2007-07-15

    The aim of our study was to evaluate attenuation-based tube current adaptation in coronary calcium scoring using ECG-gated multi-detector-row CT (MDCT). A total of 262 patients underwent non-enhanced cardiac MDCT. Group 1 was scanned using a standard protocol with 120 kV and 150 mAs{sub eff}. Groups 2-4 were scanned using an attenuation-based dose-adaptation template (CARE Dose) with different effective reference mAs settings (150, 180, 210 mAs{sub eff}). Body-mass index (BMI) and CT-dose index values were calculated for each patient. Image noise and subjective image quality were assessed. Regression analysis was performed, and the variation coefficient of image noise was determined. Compared to the standard scan protocol a dose reduction of 31.1% for group 2 and 20.1% for group 3 was observed. Measurement variation of image noise was smaller for the attenuation-based dose adaptation protocols (group 2-4) (16.2-17.1%) compared to the standard scan protocol (32.3%). Regression analysis of groups 2-4 showed better correlation with improved dose usage based on BMI (all P {<=} 0.001). Median image quality was ''excellent'' in groups 2-4 and ''good'' in group 1. Automated attenuation-based tube current adaptation in coronary calcium scoring is technically feasible, can decrease patient dose, and reduces variation in image noise as a sign of improved dose usage. (orig.)

  3. Ferromagnetic Tubes Testing Based Pulsed Remote Field Eddy Current Technique%基于脉冲远场涡流的管道内检测技术

    Institute of Scientific and Technical Information of China (English)

    杨理践; 王赓; 高松巍

    2012-01-01

    针对传统远场涡流检测方法对铁磁性管道内外壁缺陷灵敏度相同,无法有效区分缺陷在管道内壁还是管道外表面的问题,提出了采用具有丰富频率成分的脉冲激励信号取代传统的远场涡流中正弦信号激励的方法.采用小波去噪方法滤除检测数据中的信号噪声;研究了将检测线圈分别置于近场区、过渡区和远场区时的信号时域特性与管壁伤的关系;进行了针对管道管壁内外相同宽度不同深度缺陷的检测试验,结果表明采用脉冲激励作为激励源并综合运用过渡区的检测信号的幅值和过零时间特征能够有效地区分管壁内外全周向的缺陷.%In view of the traditional remote field eddy current technique for ferromagnetic tube having the same sensitivity of inner and outside walls defect,unable to distinguish the defects in the inner wall or in the outer surface,this paper adopt with abundant frequency components of the pulse signal to replace the traditional remote field eddy current sinusoidal excitation signal. Using the methods of wavelet denoising to filter acquired signal and process the data. This paper studied the relationship between the tube wall defects and signal time-domain characteristics when the detector coil was placed in the direct zone, transition zone and remote field zone. Conduct experiments to acquire data about different depth defects in the inside or outside of the walls, the results show that using the pulse signal as excitation source and characteristics about the detect signal amplitude and zero-crossing time can effectively distinguish between the inner and outer circumferential direction tube wall defects.

  4. The criterion for blanking-off heat-transfer tubes in the steam generators at VVER-based nuclear power plants based on the results of eddy-current examination

    Science.gov (United States)

    Lunin, V. P.; Zhdanov, A. G.; Chegodaev, V. V.; Stolyarov, A. A.

    2015-05-01

    The problem of defining the criterion for blanking off heat-transfer tubes in the steam generators at nuclear power plants on the basis of signals obtained from the standard multifrequency eddy-current examination is considered. The decision about blanking off one or another tube is presently made with reference to one parameter of the relevant signal at the working frequency, namely, with reference to its phase, which directly depends on the depth of the flaw being detected, i.e., a crack in the tube. The crack depth equal to 60% of the tube wall thickness is regarded to be the critical one, at which a decision about withdrawing such a tube out from operation (blanking off) must be taken. However, since mechanical tensile rupture tests of heat-transfer tubes show the possibility of their further use with such flaws, the secondary parameter of the signal, namely, its amplitude, must be used for determining the blanking-off criterion. The signals produced by the standard flow-type transducers in response to flaws in the form of a longitudinal crack having the depth and length within the limits permitted by the relevant regulations were calculated using 3D finite-element modeling. Based on the obtained results, the values of the eddy-current signal amplitude were determined, which, together with the signal phase value, form a new amplitude-phase criterion for blanking off heat-transfer tubes. For confirming the effectiveness of this technique, the algorithm for revealing the signal indications satisfying the proposed amplitude-phase criterion was tested on real signals obtained from operational eddy-current examination of the state of steam generator heat-transfer tubes carried out within the framework of planned preventive repair.

  5. 浅析钢管涡流探伤之相位分辨%Phase Distinction in Eddy Current Testing for Steel Tubes

    Institute of Scientific and Technical Information of China (English)

    林俊明

    2012-01-01

    钢管涡流探伤中,为克服铁磁性金属磁导率对探伤的影响,需要对钢管进行饱和磁化。在实际检测中有时会出现缺陷信号的相位无法分辨的问题。理论分析及试验表明,磁化导致存在涡流效应以及漏磁效应两种机理。当磁化强度过饱和时,漏磁效应强于涡流效应,由于缺陷的漏磁信号不含有相位信息,使得缺陷信号相位无法分辨;当磁化强度合适时,涡流效应占主导地位,这时检测结果阻抗平面图上的各缺陷信号的形式与非铁磁性涡流探伤结果类似,缺陷相位分辨清楚。%In the eddy current testing for steel tubes, the saturated magnetization was needed in order to reduce the effect of the magnetic permeability uncertainly. There was a problem that the phases of defect signals could not be distinguished sometimes. Theoretical analysis and experimental results showed that there were two effects, eddy current effect and magnetic flux leakage effect in this situation. When the magnetization intensity of the tubes was oversaturated, the magnetic flux leakage effect was dominant. As the signals from magnetic flux leakage effect were not related to the phase, there was no way to distinguish defects through their phase difference. On the other hand, when the magnetization was proper, the phase difference of the signal for different defects was very clear. It was the same that the appearance of testing signals in the impedance chart as the one for non-ferromagnetic materials.

  6. Automatic text summarization

    CERN Document Server

    Torres Moreno, Juan Manuel

    2014-01-01

    This new textbook examines the motivations and the different algorithms for automatic document summarization (ADS). We performed a recent state of the art. The book shows the main problems of ADS, difficulties and the solutions provided by the community. It presents recent advances in ADS, as well as current applications and trends. The approaches are statistical, linguistic and symbolic. Several exemples are included in order to clarify the theoretical concepts.  The books currently available in the area of Automatic Document Summarization are not recent. Powerful algorithms have been develop

  7. CT vs 68Ge attenuation correction in a combined PET/CT system: evaluation of the effect of lowering the CT tube current

    International Nuclear Information System (INIS)

    With the introduction of combined positron emission tomography/computed tomography (PET/CT) systems, several questions have to be answered. In this work we addressed two of these questions: (a) to what value can the CT tube current be reduced while still yielding adequate maps for the attenuation correction of PET emission scans and (b) how do quantified uptake values in tumours derived from CT and germanium-68 attenuation correction compare. In 26 tumour patients, multidetector CT scans were acquired with 10, 40, 80 and 120 mA (CT10, CT40, CT80 and CT120) and used for the attenuation correction of a single FDG PET emission scan, yielding four PET scans designated PET CT10-PET CT120. In 60 tumorous lesions, FDG uptake and lesion size were quantified on PET CT10-PET CT120. In another group of 18 patients, one CT scan acquired with 80 mA and a standard transmission scan acquired using 68Ge sources were employed for the attenuation correction of the FDG emission scan (PET CT80, PET 68Ge). Uptake values and lesion size in 26 lesions were compared on PET CT80 and PET 68Ge. In the first group of patients, analysis of variance revealed no significant effect of CT current on tumour FDG uptake or lesion size. In the second group, tumour FDG uptake was slightly higher using CT compared with 68Ge attenuation correction, especially in lesions with high FDG uptake. Lesion size was similar on PET CT80 and PET 68Ge. In conclusion, low CT currents yield adequate maps for the attenuation correction of PET emission scans. Although the discrepancy between CT- and 68Ge-derived uptake values is probably not relevant in most cases, it should be kept in mind if standardised uptake values derived from CT and 68Ge attenuation correction are compared. (orig.)

  8. A Digital Ultrasonic and Eddy Current Inspection System for Nondestructive Examination of Precision Tubes and Bars%精密管棒材数字成像无损探伤和测量系统

    Institute of Scientific and Technical Information of China (English)

    蔡桂喜; 刘畅; 林俊明; 于冰; 董瑞琪

    2012-01-01

    精密管材和棒材广泛用于核能和航空航天等领域,其细微缺陷探伤和尺寸精密测量极为重要。为此研制了精密管棒材数字成像无损探伤和测量系统。该系统由超声纵、横向缺陷探伤、超声尺寸测量、涡流探伤等子系统组成,实现了管材内壁、外壁纵横向缺陷超声探伤,棒材内部缺陷超声纵波探伤,棒材纵向缺陷超声横波探伤;棒材周向、径向缺陷超声横波探伤;管材壁厚超声测量,管材、棒材直径超声测量,管材、棒材椭圆度超声测量;管材、棒材缺陷涡流穿过式探伤及异物(渗碳等)检测,管材、棒材材料背景噪声穿过式涡流检测,管材、棒材旋转点式涡流探伤。各检测子系统均依据轴向编码器和周向编码器进行缺陷检测和尺寸测量的时基线记录显示、B扫显示和C扫成像显示,实现了高灵敏度、高分辨力、高可靠性的管材和棒材无损检测。%In nuclear and aerospace industry the widely used precision tubes and bars needed to be inspectea in detail for tiny defects and dimension of wall-thickness and diameter. An automatic examination system is designed for this purpose which is with the function of the inspection and measurement. The system is composed of ultrasonic testing sub-system for inspecting longitudinal and circumferential defects, and ultrasonic measurement sub system and eddy-current testing sub-system. The defects which could be found are longitudinal and circumferential ID and OD in pipes with ultrasound shear wave, and internal defects in bars with ultrasound longitudinal wave, and longitudinal and circumferential defects in bars with ultrasound shear wave. The ultrasonic measurement sub-system could inspect the wall-thickness of pipes and the diameter and ellipticity of pipes and bars. With bobbin coil, the defects and pollution in pipes and bars could be inspected, and the noise signal of material could be inspected also. With the

  9. Tube to tubesheet welding by electron beam for heat exchanger application

    International Nuclear Information System (INIS)

    The EB-process can successfully be used to weld in tubes into tubesheet also for those materials which are sensitiv to hot cracking. The range of qualified welding parameters has been evaluated based on a lot of metallographic and microanalysis inspections. To obtain reproducable and perfect welds a microcomputer controlled welding cycle is recommended using beam deflection, automatic seam tracking, beam current- and focus control. The results can be adopted to the specific conditions of mobile welding equipment with local vacuum. (orig.)

  10. Assessing nodule detection on lung cancer screening CT: the effects of tube current modulation and model observer selection on detectability maps

    Science.gov (United States)

    Hoffman, J. M.; Noo, F.; McMillan, K.; Young, S.; McNitt-Gray, M.

    2016-03-01

    Lung cancer screening using low dose CT has been shown to reduce lung cancer related mortality and been approved for widespread use in the US. These scans keep radiation doses low while maximizing the detection of suspicious lung lesions. Tube current modulation (TCM) is one technique used to optimize dose, however limited work has been done to assess TCM's effect on detection tasks. In this work the effect of TCM on detection is investigated throughout the lung utilizing several different model observers (MO). 131 lung nodules were simulated at 1mm intervals in each lung of the XCAT phantom. A Sensation 64 TCM profile was generated for the XCAT phantom and 2500 noise realizations were created using both TCM and a fixed TC. All nodules and noise realizations were reconstructed for a total of 262 (left and right lungs) nodule reconstructions and 10 000 XCAT lung reconstructions. Single-slice Hotelling (HO) and channelized Hotelling (CHO) observers, as well as a multislice CHO were used to assess area-under-the-curve (AUC) as a function of nodule location in both the fixed TC and TCM cases. As expected with fixed TC, nodule detectability was lowest through the shoulders and leveled off below mid-lung; with TCM, detectability was unexpectedly highest through the shoulders, dropping sharply near the mid-lung and then increasing into the abdomen. Trends were the same for all model observers. These results suggest that TCM could be further optimized for detection and that detectability maps present exciting new opportunities for TCM optimization on a patient-specific level.

  11. The nondestructive testing of tubes and pipes for nuclear application

    International Nuclear Information System (INIS)

    The directive of the Reactor Safety Commission demands for all materials which are provided for the pressure bearing enclosure of the refrigerant a nondestructive testing with sufficient sensibility. The specification 3201.1 for nuclear application as well as company-internal rules of important manufacturers regulate the requirements derived from the above direction for the NDT of tubes and pipes. For an objective and reproducible testing, equipments with defined characteristics are employed, based on internal specifications, testing equipments are fabricated and then checked with a special computerized test system. Moreover probes are controlled with regard to their acoustic and electric properties. The NDT of heat exchanger tubes and of pipes is given here as an example: Heat exchanger tubes: The tests include the inspection of longitudinal and transverse defects, wall thickness, dimension and tightness. In connection with the NDT, defect catalogues are set up. By this means the chosen test sensitivity is verified, and so the high quality of the tubes is assured. Specially developed eddy-current methods prove that such tested tubes are free of corrosion-causing phases. Pipes: The pipes are tested for longitudinal and transverse defects, for laminations and for wall thickness. To fulfil the demand for an objective and reproducible testing, there was developed and installed an automatic, computer-controlled ultrasonic equipment with 40 probes. Development trends: For the NDT of heat exchanger and boiler tubes an electrodynamic excited ultrasonic test system is evolved which is also able to test curved and installed tubes. The sophisticated testing technology is completed by a qualified education and training of NDT personnel. (orig.)

  12. Automatic Reading

    Institute of Scientific and Technical Information of China (English)

    胡迪

    2007-01-01

    <正>Reading is the key to school success and,like any skill,it takes practice.A child learns to walk by practising until he no longer has to think about how to put one foot in front of the other.The great athlete practises until he can play quickly,accurately and without thinking.Ed- ucators call it automaticity.

  13. Gastrostomy Tube (G-Tube)

    Science.gov (United States)

    ... endoscope (a thin, flexible tube with a tiny camera and light at the tip) inserted through the ... Nemours Foundation, iStock, Getty Images, Corbis, Veer, Science Photo Library, Science Source Images, Shutterstock, and Clipart.com

  14. Ear tube insertion

    Science.gov (United States)

    Myringotomy; Tympanostomy; Ear tube surgery; Pressure equalization tubes; Ventilating tubes; Ear infection - tubes; Otitis - tubes ... trapped fluid can flow out of the middle ear. This prevents hearing loss and reduces the risk ...

  15. Development of a new tube-to-tubesheet welding type for FBR's heat exchangers

    International Nuclear Information System (INIS)

    The intermediate heat exchanger for exchanging heat between primary and secondary sodium and the steam generator are required to guarantee the performance and the reliability of construction over long term under the environment of high temperature sodium peculiar to a FBR. With the increase of power output of FBR plants, the number of heating tubes and the size of tube plates of the intermediate heat exchangers of shell and tube type increase. In order to improve the reliability and the production process of the tube to tube plate welding, a new method was developed, according to which heating tubes are inserted into tube plate holes by about their thickness, and the welding of perfect penetration is carried out internally with an automatic TIG welder. At the same time, in order to confirm the reliability of the welded joints by this method, the tests for evaluating the strength for short time and long term were carried out. It was confirmed that the satisfactory performance of the welded joints was able to be obtained, and the method would be applicable to actual heat exchangers. As for the nondestructive inspection of welded joints, the radiographic method was established, and ultrasonic and eddy current flaw detection methods are being developed now. (Kako, I.)

  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. The Automatic Telescope Network (ATN)

    CERN Document Server

    Mattox, J R

    1999-01-01

    Because of the scheduled GLAST mission by NASA, there is strong scientific justification for preparation for very extensive blazar monitoring in the optical bands to exploit the opportunity to learn about blazars through the correlation of variability of the gamma-ray flux with flux at lower frequencies. Current optical facilities do not provide the required capability.Developments in technology have enabled astronomers to readily deploy automatic telescopes. The effort to create an Automatic Telescope Network (ATN) for blazar monitoring in the GLAST era is described. Other scientific applications of the networks of automatic telescopes are discussed. The potential of the ATN for science education is also discussed.

  18. Reference factor F(CT)Q and X ray tube ionization yield R(TUBE)Q

    International Nuclear Information System (INIS)

    The operational facility procedures in diagnostic radiology standardization and calibration, through the relation between the X ray tube current and the ionization chamber current in a radiation quality Q, shown the reference factor F(CT)Q as the reality estimate to the X ray tube ionization yield, R(TUBE)Q . (author)

  19. Study on an Automatic Knife Switch of New Type High-Voltage Small Current Reactor%新型高电压小电流电抗器自动刀闸的研究

    Institute of Scientific and Technical Information of China (English)

    许杰; 李世武; 孙伟

    2014-01-01

    针对当前电抗器投切刀闸存在的投切行程小、适用范围受限制、远程操控不方便等问题,研发了一种新型的高电压小电流电抗器自动刀闸,给出了自动刀闸结构图,分析了其工作原理。对该自动刀闸进行峰值耐受电流试验和机械操作试验,测试结果符合要求,有效通断率100%,提高了电抗器串并联自动化程度,易于远程控制且性能稳定,可广泛用于电力系统机构的各项试验。%Aiming at several problems such that the existing reactor knife switch is small in travel distance for knife making and breaking, limited in applicable range, not convenient in remote operating etc., this paper developed an automatic knife switch of new type high-voltage small current reactor and gave the structural diagram of the automatic knife switch, analyzing its working principle. The peak value withstand current and mechanical operating tests were carried out for the automatic knife switch. The test results are in conformity to the requirements, with 100% valid making-breaking rate, which raises the reactor serial and parallel connection automation degree, easy for remote control and stable in performance. The switch could be widely used in each test of electric power system organization.

  20. Neutron tubes

    Science.gov (United States)

    Leung, Ka-Ngo; Lou, Tak Pui; Reijonen, Jani

    2008-03-11

    A neutron tube or generator is based on a RF driven plasma ion source having a quartz or other chamber surrounded by an external RF antenna. A deuterium or mixed deuterium/tritium (or even just a tritium) plasma is generated in the chamber and D or D/T (or T) ions are extracted from the plasma. A neutron generating target is positioned so that the ion beam is incident thereon and loads the target. Incident ions cause D-D or D-T (or T-T) reactions which generate neutrons. Various embodiments differ primarily in size of the chamber and position and shape of the neutron generating target. Some neutron generators are small enough for implantation in the body. The target may be at the end of a catheter-like drift tube. The target may have a tapered or conical surface to increase target surface area.

  1. Straightening tubes

    International Nuclear Information System (INIS)

    Hexagonal wrapper tubes, especially for nuclear reactor core sub-assemblies, may suffer from unacceptable bow as a result of welding wear pads to the wrapper and heat treatment. Straightening of the bow is effected by a method wherein at each of a series of axially spaced locations the faces or vertices of the tube are measured relative to a reference to determine the direction of bow at the locations. From these measurements, the appropriate axial locations for the application of corrective loading can be determined, whereby by application of the loading at a selected face or vertex for such measurements the bow is reduced. Such loading, by an actuator, can be repeated at the locations until the bow is reduced to within tolerances. (author)

  2. 小孔径自动钨极氩弧焊在管板焊接中的应用%Application of small hole automatic GTAW for tube-sheet welding

    Institute of Scientific and Technical Information of China (English)

    孟震

    2011-01-01

    This paper introduced a new special welding machine and welding tooling for small hole inside wire filling of tube sheet joint in argon arc welding machine in the tube sheet welding through test and ensured groove preparation methods and welding procedure parameters,by the X-ray test,corrosion test,macro metallographic test,pulled off the test and so on which the results that were satisfactory with welding quality and product requirements.For later the small holes of wire filling welding provides certain theoretical basis for future.%介绍了一种专用于小孔内填丝的新型管板接头氩孤焊机和机头在管板焊接工作中的应用,通过多次规范试验验证并最终确定坡口制备方式和焊接规范参数,焊接后经过射线检测、腐蚀试验、宏观金相试验、拉脱试验等的验证,确保焊接接头获得满意的焊接质量,为以后小孔内填丝焊接制造技术提供了一定的理论基础.

  3. Alternate tube plugging criteria for steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Cueto-Felgueroso, C.; Aparicio, C.B. [Tecnatom, S.A., Madrid (Spain)

    1997-02-01

    The tubing of the Steam Generators constitutes more than half of the reactor coolant pressure boundary. Specific requirements governing the maintenance of steam generator tubes integrity are set in Plant Technical Specifications and in Section XI of the ASME Boiler and Pressure Vessel Code. The operating experience of Steam Generator tubes of PWR plants has shown the existence of some types of degradatory processes. Every one of these has an specific cause and affects one or more zones of the tubes. In the case of Spanish Power Plants, and depending on the particular Plant considered, they should be mentioned the Primary Water Stress Corrosion Cracking (PWSCC) at the roll transition zone (RTZ), the Outside Diameter Stress Corrosion Cracking (ODSCC) at the Tube Support Plate (TSP) intersections and the fretting with the Anti-Vibration Bars (AVBs) or with the Support Plates in the preheater zone. The In-Service Inspections by Eddy Currents constitutes the standard method for assuring the SG tubes integrity and they permit the monitoring of the defects during the service life of the plant. When the degradation reaches a determined limit, called the plugging limit, the SG tube must be either repaired or retired from service by plugging. Customarily, the plugging limit is related to the depth of the defect. Such depth is typically 40% of the wall thickness of the tube and is applicable to any type of defect in the tube. In its origin, that limit was established for tubes thinned by wastage, which was the predominant degradation in the seventies. The application of this criterion for axial crack-like defects, as, for instance, those due to PWSCC in the roll transition zone, has lead to an excessive and unnecessary number of tubes being plugged. This has lead to the development of defect specific plugging criteria. Examples of the application of such criteria are discussed in the article.

  4. Automatic Radiation Monitoring in Slovenia

    International Nuclear Information System (INIS)

    Full text: The automatic radiation monitoring system in Slovenia started in early nineties and now it comprises measurements of: 1. External gamma radiation: For the time being there are forty-three probes with GM tubes integrated into a common automatic network, operated at the SNSA. The probes measure dose rate in 30 minute intervals. 2. Aerosol radioactivity: Three automatic aerosol stations measure the concentration of artificial alpha and beta activity in the air, gamma emitting radionuclides, radioactive iodine 131 in the air (in all chemical forms, - natural radon and thoron progeny, 3. Radon progeny concentration: Radon progeny concentration is measured hourly and results are displayed as the equilibrium equivalent concentrations (EEC), 4. Radioactive deposition measurements: As a support to gamma dose rate measurements - the SNSA developed and installed an automatic measuring station for surface contamination equipped with gamma spectrometry system (with 3x3' NaI(Tl) detector). All data are transferred through the different communication pathways to the SNSA. They are collected in 30 minute intervals. Within these intervals the central computer analyses and processes the collected data, and creates different reports. Every month QA/QC analysis of data is performed, showing the statistics of acquisition errors and availability of measuring results. All results are promptly available at the our WEB pages. The data are checked and daily sent to the EURDEP system at Ispra (Italy) and also to the Austrian, Croatian and Hungarian authorities. (author)

  5. 非介入技术在X光机管电流测量中的应用研究%Application of non-invasive technology in X-ray tube current measurement

    Institute of Scientific and Technical Information of China (English)

    黄平; 龚岚; 刘志宏

    2012-01-01

    X-ray machine is widely used in diagnostic radiology, radiotherapy, industrial testing and other related fields. It plays an important role in protecting the health of citizens and promoting social -economic ? Progress. As an important parameter of the intensity of X-ray, the current of X-ray tube has a major impact on the X-ray output quality, the clarity of pictures and other aspects. In order to ensure the accuracy of testing data and simplify the certification process, a testing method was designed on the basis of the non-invasive to measure the current of X-ray tube. Experimental results show that the method can accurately measure the X-ray tube's current.%X光机广泛应用于放射诊断、放射治疗、工业探伤等相关领域,在保障公民身体健康和促进社会经济进步方面发挥着重要作用.X光机管电流作为控制X射线强度的重要参数,对射线输出质量、拍片清晰度等方面产生重要影响.在保证检测数据准确、检定过程简易的情况下,设计采用了基于非介入式的X光机管电流测量方法,测试结果表明该方法能准确测量X光机管电流.

  6. Infrared imaging of LED lighting tubes and fluorescent tubes

    Science.gov (United States)

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

    2011-05-01

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

  7. Perfection of processes of seamless steel tubes production

    Directory of Open Access Journals (Sweden)

    YU. G. Gulyayev

    2011-10-01

    Full Text Available The article first give a review more of hundret years long history of seamless steel tube production, especially during the last 15-20 years of the 20th century. Prolongation, article give technological indices for 4 mills (automatical, continuous mill, pilger, Assel, and perfectation of processes seamless steel tubes production at the begining of 21st century.

  8. Perfection of processes of seamless steel tubes production

    OpenAIRE

    Gulyayev, Yu. G.; Ilija Mamuzić; Shyfrin, Ye. I.; Buršak, M.; D. YU. Garmashev

    2011-01-01

    The article first give a review more of hundret years long history of seamless steel tube production, especially during the last 15-20 years of the 20th century. Prolongation, article give technological indices for 4 mills (automatical, continuous mill, pilger, Assel), and perfectation of processes seamless steel tubes production at the begining of 21st century.

  9. Variable load automatically tests dc power supplies

    Science.gov (United States)

    Burke, H. C., Jr.; Sullivan, R. M.

    1965-01-01

    Continuously variable load automatically tests dc power supplies over an extended current range. External meters monitor current and voltage, and multipliers at the outputs facilitate plotting the power curve of the unit.

  10. Tube furnace

    Science.gov (United States)

    Foster, Kenneth G.; Frohwein, Eugene J.; Taylor, Robert W.; Bowen, David W.

    1991-01-01

    A vermiculite insulated tube furnace is heated by a helically-wound resistance wire positioned within a helical groove on the surface of a ceramic cylinder, that in turn is surroundingly disposed about a doubly slotted stainless steel cylindrical liner. For uniform heating, the pitch of the helix is of shorter length over the two end portions of the ceramic cylinder. The furnace is of large volume, provides uniform temperature, offers an extremely precise programmed heating capability, features very rapid cool-down, and has a modest electrical power requirement.

  11. Test Station for Measuring Aluminum Tube Geometrical Parameters

    CERN Document Server

    Oansea, D; Gongadze, A L; Gostkin, M I; Dedovich, D V; Evtoukhovitch, P G; Comanescu, B; Kotov, S A; Necsoiu, T; Potrap, I N; Rogalev, E V; Tskhadadze, E G; Chelkov, G A

    2001-01-01

    A test station for quality control of aluminum tube outer diameter and wall thickness is presented. The tested tubes are used for drift detector assembly of ATLAS (LHC, CERN) muon system. The outer diameter and wall thickness of aluminium tubes are measured by means of noncontact optical and ultrasonic methods respectively with the accuracy of 3 {\\mu}m. The testing process is automatic and interacts with the production data base.

  12. 煤矿低压电网漏电容性电流自动补偿研究%Research on Capacitive Current Automatic Compensation on Low Voltage Power Grid Leakage Protection of Coal Mine

    Institute of Scientific and Technical Information of China (English)

    徐国萍

    2014-01-01

    In neutral insulation low voltage power supply lines of coal mine,due to distributed capacitance exists, the leakage currents or personal electric shock currents exceed the limited safety value, and the changes of distributed capacitance easily cause the original system overcompensation or under compensation. The automatic compensation scheme of combining inductance the coarse adjustment with the fine adjustment is proposed on base of the minimum leakage currents closed loop control theory. Using single chip microcomputer control relay automatic switching magnetic amplifier is to achieve multi tap AC winding inductance step adjustment. The currents of magnetic amplifier DC winding are changed by single chip microcomputer control step motor to adjust potentiometer. The system attains stepless regulation of the inductance, so that the currents of distributed capacitance are completely compensated by the inductor currents of the magnetic amplifier. It has many advantages of fast compensation speed, high precision, short cycle, safety and easy operation during compensation process.%针对煤矿井下中性点绝缘低压供电线路中,由于电网对地分布电容的存在,使漏电电流或人身触电电流超过极限安全值,并且电网分布电容的多变容易引起原系统过补偿或欠补偿的情况,提出基于最小漏电电流闭环控制理论的电感量粗调和细调相融合的自动补偿方案,采用单片机控制继电器自动切换磁放大器多抽头交流绕组实现电感量有级调节,通过步进电机调节电位器改变磁放大器直流绕组的电流,实现电感量无级调节,从而使流过磁放大器的电感电流完全补偿电网分布电容的电流。该系统补偿速度快、精度高、调整周期短,补偿过程操作方便、安全。

  13. A tube-in-tube thermophotovoltaic generator

    Energy Technology Data Exchange (ETDEWEB)

    Ashcroft, J.; Campbell, B.; Depoy, D.

    1996-12-31

    A thermophotovoltaic device includes at least one thermal radiator tube, a cooling tube concentrically disposed within each thermal radiator tube and an array of thermophotovoltaic cells disposed on the exterior surface of the cooling tube. A shell having a first end and a second end surrounds the thermal radiator tube. Inner and outer tubesheets, each having an aperture corresponding to each cooling tube, are located at each end of the shell. The thermal radiator tube extends within the shell between the inner tubesheets. The cooling tube extends within the shell through the corresponding apertures of the two inner tubesheets to the corresponding apertures of the two outer tubesheets. A plurality of the thermal radiator tubes can be arranged in a staggered or an in-line configuration within the shell.

  14. Evaluation of automatic exposure control systems in computed tomography

    International Nuclear Information System (INIS)

    The development of the computed tomography (CT) technology has brought wider possibilities on diagnostic medicine. It is a non-invasive method to see the human body in details. As the CT application increases, it raises the concern about patient dose, because the higher dose levels imparted compared to other diagnostic imaging modalities. The radiology community (radiologists, medical physicists and manufacturer) are working together to find the lowest dose level possible, without compromising the diagnostic image quality. The greatest and relatively new advance to lower the patient dose is the automatic exposure control (AEC) systems in CT. These systems are designed to ponder the dose distribution along the patient scanning and between patients taking into account their sizes and irradiated tissue densities. Based on the CT scanning geometry, the AEC-systems are very complex and their functioning is yet not fully understood. This work aims to evaluate the clinical performance of AEC-systems and their susceptibilities to assist on possible patient dose optimizations. The approach to evaluate the AEC-systems of three of the leading CT manufacturers in Brazil, General Electric, Philips and Toshiba, was the extraction of tube current modulation data from the DICOM standard image sequences, measurement and analysis of the image noise of those image sequences and measurement of the dose distribution along the scan length on the surface and inside of two different phantoms configurations. The tube current modulation of each CT scanner associated to the resulted image quality provides the performance of the AECsystem. The dose distribution measurements provide the dose profile due to the tube current modulation. Dose measurements with the AEC-system ON and OFF were made to quantify the impact of these systems regarding patient dose. The results attained give rise to optimizations on the AEC-systems applications and, by consequence, decreases the patient dose without

  15. Wall thickness gauging device for moved glass tubes

    International Nuclear Information System (INIS)

    The invention has been aimed at a wall thickness gauging device for moved glass tubes on the basis of isotopic measuring techniques and can be applied to the glass tube production. Faulty measurements due to alterations of the glass tube position during the manufacturing process can be avoided. An auxiliary attachment has been established which makes it possible to detect position errors of the glass tube with regard to the measuring equipment and to carry out a correction of the measuring equipment position. By means of opto-electronic measuring equipment the position of tube edges is determined and in the case of a deviation from the prescribed position due to glass tube movement the wall thickness gauging device will automatically follow up the tube

  16. Titanium condenser tubes

    International Nuclear Information System (INIS)

    The corrosion resistance of titanium in sea water is extremely excellent, but titanium tubes are expensive, and the copper alloy tubes resistant in polluted sea water were developed, therefore they were not used practically. In 1970, ammonia attack was found on the copper alloy tubes in the air-cooled portion of condensers, and titanium tubes have been used as the countermeasure. As the result of the use, the galvanic attack an copper alloy tube plates with titanium tubes as cathode and the hydrogen absorption at titanium tube ends owing to excess electrolytic protection were observed, but the corrosion resistance of titanium tubes was perfect. These problems can be controlled by the application of proper electrolytic protection. The condensers with all titanium tubes adopted recently in USA are intended to realize perfectly no-leak condensers as the countermeasure to the corrosion in steam generators of PWR plants. Regarding large condensers of nowadays, three problems are pointed out, namely the vibration of condenser tubes, the method of joining tubes and tube plates, and the tubes of no coolant leak. These three problems in case of titanium tubes were studied, and the problem of the fouling of tubes was also examined. The intervals of supporting plates for titanium tubes should be narrowed. The joining of titanium tubes and titanium tube plates by welding is feasible and promising. The cleaning with sponge balls is effective to control fouling. (Kako, I.)

  17. Enhancement of transport critical current density of SmFeAsO{sub 1−x}F{sub x} tapes fabricated by an ex-situ powder-in-tube method with a Sn-presintering process

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Qianjun; Yao, Chao; Lin, He; Zhang, Xianping; Wang, Dongliang; Dong, Chiheng; Yuan, Pusheng; Tang, Shaopu; Ma, Yanwei, E-mail: ywma@mail.iee.ac.cn [Key Laboratory of Applied Superconductivity, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Awaji, Satoshi; Watanabe, Kazuo [High Field Laboratory for Superconducting Materials, Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Tsuchiya, Yuji; Tamegai, Tsuyoshi [Department of Applied Physics, The University of Tokyo, Hongo, Tokyo 113-8656 (Japan)

    2014-04-28

    SmFeAsO{sub 1−x}F{sub x} (Sm1111) tapes were prepared by an ex-situ powder-in-tube method with a Sn-presintering process. Scanning electron microscopy revealed apparent difference in microstructure between Sn-presintered tapes and the previously reported polycrystalline Sm1111 bulk, since Sn has reduced FeAs wetting phase and filled the voids between Sm1111 grains. The Sn-presintered tapes showed significant enhanced field dependences of transport J{sub c} compared with Sn-added tapes. A highest transport critical current density (J{sub c}) of 3.45 × 10{sup 4} A cm{sup −2} at 4.2 K and self-field is achieved. Magneto-optical imaging further confirmed large and well-distributed global and intergranular J{sub c} in Sn-presintered Sm1111 tapes.

  18. 自动流量平衡阀过流端帽的激光强化研究%Research on Laser Enhancement for Automatic Flow Valve Over-current End Cap

    Institute of Scientific and Technical Information of China (English)

    王斌修; 贺敬地

    2012-01-01

    利用激光表面强化技术对自动流量平衡阀过流端帽工作面进行强化以增加其使用寿命.详细分析了不同激光参数如脉冲电流、扫描速度、脉冲频率和离焦量等因素对过流端帽表面硬化的影响.实验结果表明:只要工艺参数选择适当,可获得很好的表面硬化质量,且能提高生产效率.%Over-current end cap of automatic flow control valves was strengthened by using laser surface strengthening technology in order to increase its service life. The influences of the different laser parameters to surface strengthening, such as laser pulse current , scanning speed, pulse frequency and defocus, were analyzed. Experimental results show that as long as the appropriate laser parameters be chosen, good surface hardening quality can be obtained, and the production efficiency can be improved.

  19. Gastroenteric tube feeding: Techniques, problems and solutions

    Science.gov (United States)

    Blumenstein, Irina; Shastri, Yogesh M; Stein, Jürgen

    2014-01-01

    Gastroenteric tube feeding plays a major role in the management of patients with poor voluntary intake, chronic neurological or mechanical dysphagia or gut dysfunction, and patients who are critically ill. However, despite the benefits and widespread use of enteral tube feeding, some patients experience complications. This review aims to discuss and compare current knowledge regarding the clinical application of enteral tube feeding, together with associated complications and special aspects. We conducted an extensive literature search on PubMed, Embase and Medline using index terms relating to enteral access, enteral feeding/nutrition, tube feeding, percutaneous endoscopic gastrostomy/jejunostomy, endoscopic nasoenteric tube, nasogastric tube, and refeeding syndrome. The literature showed common routes of enteral access to include nasoenteral tube, gastrostomy and jejunostomy, while complications fall into four major categories: mechanical, e.g., tube blockage or removal; gastrointestinal, e.g., diarrhea; infectious e.g., aspiration pneumonia, tube site infection; and metabolic, e.g., refeeding syndrome, hyperglycemia. Although the type and frequency of complications arising from tube feeding vary considerably according to the chosen access route, gastrointestinal complications are without doubt the most common. Complications associated with enteral tube feeding can be reduced by careful observance of guidelines, including those related to food composition, administration rate, portion size, food temperature and patient supervision. PMID:25024606

  20. Gastroenteric tube feeding: techniques, problems and solutions.

    Science.gov (United States)

    Blumenstein, Irina; Shastri, Yogesh M; Stein, Jürgen

    2014-07-14

    Gastroenteric tube feeding plays a major role in the management of patients with poor voluntary intake, chronic neurological or mechanical dysphagia or gut dysfunction, and patients who are critically ill. However, despite the benefits and widespread use of enteral tube feeding, some patients experience complications. This review aims to discuss and compare current knowledge regarding the clinical application of enteral tube feeding, together with associated complications and special aspects. We conducted an extensive literature search on PubMed, Embase and Medline using index terms relating to enteral access, enteral feeding/nutrition, tube feeding, percutaneous endoscopic gastrostomy/jejunostomy, endoscopic nasoenteric tube, nasogastric tube, and refeeding syndrome. The literature showed common routes of enteral access to include nasoenteral tube, gastrostomy and jejunostomy, while complications fall into four major categories: mechanical, e.g., tube blockage or removal; gastrointestinal, e.g., diarrhea; infectious e.g., aspiration pneumonia, tube site infection; and metabolic, e.g., refeeding syndrome, hyperglycemia. Although the type and frequency of complications arising from tube feeding vary considerably according to the chosen access route, gastrointestinal complications are without doubt the most common. Complications associated with enteral tube feeding can be reduced by careful observance of guidelines, including those related to food composition, administration rate, portion size, food temperature and patient supervision.

  1. Reference factor F{sub (CT)Q} and X ray tube ionization yield R{sub (TUBE)Q}

    Energy Technology Data Exchange (ETDEWEB)

    Quaresma, D.S. [Observatorio Nacional, Rio de Janeiro, RJ (Brazil); Cardoso, R.S.; Peixoto, J.G.P., E-mail: dansq@on.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    The operational facility procedures in diagnostic radiology standardization and calibration, through the relation between the X ray tube current and the ionization chamber current in a radiation quality Q, shown the reference factor F{sub (CT)Q} as the reality estimate to the X ray tube ionization yield, R{sub (TUBE)Q} . (author)

  2. Study on Eddy Current Testing Signal under Different Through-hole Diameters of Steel Tube%钢管通孔直径对涡流检测信号的影响研究

    Institute of Scientific and Technical Information of China (English)

    宋凯; 彭旭钊; 危荃; 李来平; 涂俊; 马冰洋

    2015-01-01

    为研究通孔直径在钢管涡流检测中对检测信号的影响,开展了不同磁化强度下钢管通孔涡流检测试验,研究了不同直径通孔随磁化电流的信号变化特征。试验结果表明:通孔直径一定时,在非饱和磁化区(6~18 A)内,信号幅值随电流的增加先增大后减小,相位角随电流的增加逐步上升,在饱和磁化区(20~22 A)内,检测信号成形较小或严重扭曲,相位变化杂乱无章;当磁化电流一定时,信号幅值随通孔直径的增大而增大,不同直径通孔间信号相位角在非饱和磁化区(6~18 A)内,最大值与最小值的极值偏差在10°~18°范围内变化,差异较小,而在饱和磁化区(20~22 A)信号相位角变化起伏较大,无明显规律。试验研究结果可用于指导钢管涡流检测工程实践。%The effect of through-hole diameter of steel tube on eddy current testing ( ECT ) signal is not clear. An ECT experiment of the through-hole of steel tube under different magnetization current is carried out. The ECT experiment is to study on ECT signal under different through-hole diameters with different magnetization current. The experimental results show that when the through-hole diameter is constant, under the region of unsaturated magnetization( 6 ~18 A), the signal amplitude increases first and then decreases with the increase of the magnetization current, signal phase increases gradually with the increase of the magnetization current. Under the region of saturated magnetization (20 ~22 A),the graph of ECT signal is so small or seriously distort, the variation of signal phase is disorder. When the magnetization current is constant, signal amplitude increases with the increase of through-hole diameter; under the region of unsaturated magnetization ( 6 ~18 A ) , the extreme deviation of the maximum and the minimum of different through-hole diameters’ signal phase varies in 10° ~18°. Under the region of saturated

  3. Ultrasonic-test-equipment for rotation tubes

    International Nuclear Information System (INIS)

    The paper describes specifications and the configuration of a ultrasonic equipment for the testing of spinning tubes. Specifications: - Flaw detection inside and outside (resolution of 5μm), Wa-1 thickness measurement (accuracy +- 1,5μ), inner diameter measurement (accuracy +- 20μ), On-Line data processing, equipment completely automatic controlled. The results concerning measurement accuracy, reproducibility and stability during test conditions are presented. (orig.)

  4. photomultiplier tube

    CERN Multimedia

    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.

  5. photomultiplier tube

    CERN Multimedia

    Philips. 150AVP. 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.

  6. Development of INCONEL 600 precision tube (1)

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Yeong Han; Jo, Bong Hyeon; Lee, Dong Hee; Kim, Wan Kyo; Jeong, Pyeong Keun; Yoon, Hwang Lo; Chio, Seok Sik [Sammi Steel Co. Ltd., Changwon (Korea, Republic of)

    1994-07-01

    Steam generator, being connected with nuclear fuel reactor is one of the most important part of nuclear power plant and consists of a large number of INCONEL 600 tubes. Approximately 160 tons of tubes are needed for a single nuclear power plant. All of INCONEL 600 steam generator tubes for domestic nuclear power plants have been imported. The aim of this research is to develop INCONEL 600 precision tubes for steam generator of nuclear power plant. If this research is conducted successfully, we can produce nuclear fuel tubes, Ni-alloy precision tubes and stainless steel precision tubes for many purposes and technology of INCONEL 600 steam generator tubes are similar to those of other tubes above mentioned. In the current study, development of preliminary manufacturing process of INCONEL 600 precision tubes for steam generator and investigation of material`s metallurgical characteristics were conducted. The main scope of this research is as follows. First, the preliminary manufacturing process design was conducted after investigations of foreign manufacturing processes and technical reports. Second, the results of investigations of material`s metallurgical characteristics through the manufacturing process were applied to the production technology of tentative INCONEL 600 precision tubes for sample. Third, preliminary process routes were established and samples of INCONEL 600 precision tube were produced by this process. As the results of this research, 14 pieces of INCONEL 600 precision tubes were produced by preliminary manufacturing process and the material`s metallurgical characteristics were investigated through the processes. But the SCC test could not be conducted due to the absence of equipment. In order to apply the results of SCC test to the manufacturing process, we need a SCC tester which can simulate SCC characteristics under high temperature and high pressurized circulating water. 95 refs., 55 figs., 20 tabs.

  7. 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.

  8. Optimization of recommendations for abdomen computerized tomography based on reconstruction filters, voltage and tube current; Otimizacao de protocolos de tomografia computadorizada de abdome com base nos filtros de reconstrucao, tensao e corrente do tubo

    Energy Technology Data Exchange (ETDEWEB)

    Silveira, Vinicius da Costa

    2015-07-01

    The use of computed tomography has increased significantly over the past decades. In Brazil the use increased more than twofold from 2008 to 2014, in the meantime the abdomen procedures have tripled. The high frequency of this procedure combined by the increasing collective radiation dose in medical exposures, has resulted development tools to maximize the benefit in CT images. This work aimed to establish protocols optimized in abdominal CT through acquisitions parameters and reconstructions techniques based on filters kernels. A sample of patients undergoing abdominal CT in a diagnostic center of Rio de Janeiro was assessed. Had been collected patients information and acquisitions parameters. The phantoms CT image acquisitions were performed by using different voltage values by adjusting the tube current (mAs) to obtain the same value from CTDI{sub vol} patients with normal BMI. Afterwards, the CTDIvol values were reduced by 30%, 50% and 60%. All images were reconstructed with low-contrast filters (A) and standard filters (B). The CTDIvol values for patients with normal BMI were 7% higher than in patients with underweight BMI and 30%, 50% and 60% lower than the overweight, obese I and III patients, respectively. The evaluations of image quality showed that variation of the current (mA) and the reconstruction filters did not affect the Hounsfield values. When the contrast-to-noise ratio (CNR) was normalized to CTDIvol, the protocols acquired with 60% reduction of CTDIvol with 140 kV and 80 kV showed CNR 6% lower than the routine. Modifications of the acquisition parameters did not affect spatial resolution, but the post-processing with B filters reduced the spatial frequency by 16%. With reduced the dose of 30%, lesions in the spleen had the CNR higher than 10% routine protocols with 140 kV acquired and post-processed to filter A. The image post-processing with a filter A with a 80kV voltage provided CNR values equal to the routine for the liver lesions with a 30

  9. Automatic Fiscal Stabilizers

    Directory of Open Access Journals (Sweden)

    Narcis Eduard Mitu

    2013-11-01

    Full Text Available Policies or institutions (built into an economic system that automatically tend to dampen economic cycle fluctuations in income, employment, etc., without direct government intervention. For example, in boom times, progressive income tax automatically reduces money supply as incomes and spendings rise. Similarly, in recessionary times, payment of unemployment benefits injects more money in the system and stimulates demand. Also called automatic stabilizers or built-in stabilizers.

  10. Automatic input rectification

    OpenAIRE

    Long, Fan; Ganesh, Vijay; Carbin, Michael James; Sidiroglou, Stelios; Rinard, Martin

    2012-01-01

    We present a novel technique, automatic input rectification, and a prototype implementation, SOAP. SOAP learns a set of constraints characterizing typical inputs that an application is highly likely to process correctly. When given an atypical input that does not satisfy these constraints, SOAP automatically rectifies the input (i.e., changes the input so that it satisfies the learned constraints). The goal is to automatically convert potentially dangerous inputs into typical inputs that the ...

  11. Automation of the Tube-Thickness Measurements Using Ultrasonics

    International Nuclear Information System (INIS)

    Two ultrasonic methods for automatically measuring the wall thickness of thin-walled metal tubing are described and compared for accuracy and measurement rate. These methods are: (a) A double-probe method using an ultrasonic plane transmitter crystal to irradiate a small area of tube wall and a separate receiving crystal adjusted to receive energy from this same area; the two probes are mounted close to each other. As the transmitter frequency is varied, the receiver output shows an absorption resonance when the ultrasonic wavelength corresponds to twice the tube thickness. The paper describes the electronic circuits used to automatically adjust the frequency to keep the receiver output at minimum. By measuring this frequency a record in digital form of the thickness of the tube may be obtained. (b) A single-probe method using a focused transmitter probe directing a burst of energy, typically 30 μs duration of 5 MHz frequency, at normal incidence to the tube wall; the same probe acts as a receiver and electronic circuits are used to select the first reflected pulses. The paper describes how the transmitter frequency is varied automatically over a selected range and how the frequency at which a minimum reflected pulse occurs is selected and measured. This minimum occurs at a wavelength of twice the tube wall thickness so that again a direct digital measurement of thickness is achieved. (author)

  12. Automatic differentiation bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Corliss, G.F. (comp.)

    1992-07-01

    This is a bibliography of work related to automatic differentiation. Automatic differentiation is a technique for the fast, accurate propagation of derivative values using the chain rule. It is neither symbolic nor numeric. Automatic differentiation is a fundamental tool for scientific computation, with applications in optimization, nonlinear equations, nonlinear least squares approximation, stiff ordinary differential equation, partial differential equations, continuation methods, and sensitivity analysis. This report is an updated version of the bibliography which originally appeared in Automatic Differentiation of Algorithms: Theory, Implementation, and Application.

  13. Tracheostomy tube - speaking

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000465.htm Tracheostomy tube - speaking To use the sharing features on ... are even speaking devices that can help you. Tracheostomy Tubes and Speaking Air passing through vocal cords ( ...

  14. 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 ...

  15. Development and formability analysis of TRIP seamless steel tube

    Institute of Scientific and Technical Information of China (English)

    Zhang Zicheng; Zhu Fuxian

    2014-01-01

    In this paper, the production technology of transformation induced plasticity (TRIP) steel was first introduced into the steel tube manufacture field to produce the steel tubes with high strength and plasticity. The TRIP seamless steel tubes with the microstructure of ferrite, bainite, retained austenite and a little martensite were successfully fabricated using a cold-drawn steel tube with two-stage heat treatment technique and continu- ous heat treatment process, respectively. The ring tensile test and cold bend test were carried out to study the formability of the newly developed TRIP seamless steel tube. The results showed that the TRIP seamless steel tubes have a good cold formability, and they are available to be used in the tube hydroforming process. In ad- dition, the equipment of continuous heat treatment developed in the current study can be used to produce TRIP steel tube, and it may serve as an important reference for the industrial production of TRIP steel tube.

  16. Development of ultrasonic testing scanner for NPP steam generator tubes (I)

    Energy Technology Data Exchange (ETDEWEB)

    Shin, J. I.; Huh, H

    1998-12-01

    Testing tubes are designed and fabricated to investigate the optimum test conditions through the various experiments. The proto-type P/C-controlled automatic rotating scanner is fabricated to obtain the ultrasonic data automatically from test tubes. It was attempted to visualize the shape of defects presented inside the specimen using peak amplitude at each point. However, further research works will be needed to be applied at the plant site as a more reliable technology.

  17. Development of ultrasonic testing scanner for NPP steam generator tubes (I)

    International Nuclear Information System (INIS)

    Testing tubes are designed and fabricated to investigate the optimum test conditions through the various experiments. The proto-type P/C-controlled automatic rotating scanner is fabricated to obtain the ultrasonic data automatically from test tubes. It was attempted to visualize the shape of defects presented inside the specimen using peak amplitude at each point. However, further research works will be needed to be applied at the plant site as a more reliable technology

  18. Development of the boiler tube wall thickness ultrasonic detector

    International Nuclear Information System (INIS)

    Wall thickness of fossil fuel firing power boiler tubes are measured by ultrasonic test at regular intervals as part of in-service inspections. The measuring tubes are located high up on the boiler and at restricted sites, and many man-hours are required for preparatory of boiler tube wall thickness scale removal. To improve the efficiency and reliability of boiler tube wall thickness measurements, a system was developed for measuring the tube wall thickness by ultrasonic test from inside the tube. The primary features of this system are: 1) polishing on the outersurface of boiler tubes is not necessary because measurements are made from inside. (Reduction of man-hours), 2) measurements in limited places where manual measurement is difficult or impossible is made possible because automatic measurement from inside the tube is made by an ultrasonic probe introduced into the tube from the inspection hole of the header. (Improvement of reliability), and 3) the tube wall thickness is measured by a submerged ultrasonic rotary probe at an accuracy of ±0.1 mm along the full length. (Improvement of reliability)

  19. 带包覆层铁磁性管道腐蚀脉冲涡流检测技术%Pulsed Eddy Current Inspection Technique in for Corrosion under Insulation in Ferromagnetic Tubes

    Institute of Scientific and Technical Information of China (English)

    康小伟; 付跃文

    2011-01-01

    In this paper, we applied pulsed eddy current(PEC} inspection technique to detect ferromagnetic tubes corrosion under insulation. By detecting corrosion of different thickness insulation and different defect areas and deepness, variation of detection sensitivity was analyzed. It was proved that as for corrosion defect with a large area, pulsed eddy current had a very good ability in testing under appropriate inspection parameters, even with a thick insulation.%应用脉冲涡流检测技术,对带包覆层的铁磁性管道腐蚀进行了检测。对不同厚度的包覆层、不同面积和深度的腐蚀缺陷进行了试验,分析检测灵敏度的变化。试验结果表明,对于较大面积的腐蚀缺陷,即使包覆层较厚,在合适的检测参数下,脉冲涡流也具有很好的检测能力。

  20. 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...

  1. Update on seamless calandria tube development and qualification

    International Nuclear Information System (INIS)

    AECL is undertaking the qualification of the production of seamless calandria tubes as replacement components for installation in reactors during retubing. Seamless tube prototypes made from Zircaloy-2 possessing a suitable crystallographic texture have been shown to be significantly stronger than seam-welded tubes under both rising pressure and sustained pressure conditions in a simulated reactor loading. This paper describes the seamless calandria tube development program and current status. (author)

  2. Test and Design of Current Comparator Bridge’s Automatic Balancing Algorithm%电流比较仪式电桥自动平衡算法设计与测试

    Institute of Scientific and Technical Information of China (English)

    陆沈敏; 李刚; 赵刚

    2013-01-01

      This paper designs an automatic balancing algorithm of current comparator bridge to get dielectric loss tanδ and capacitance. In order to eliminate unbalanced state between test capacitor arm and standard capacitor arm, the algorithm outputs the parameter (N2 turns & gain β) to make output voltage tend to zero by measuring the null detector output voltage and current of standard capacitor bridge arm. And it also uses Newton-Raphson iteration method to get more accurate parameter and then calculate tanδand capacitance value. This paper tests the capability of the algorithm in a condition of the power with stable frequency, changing frequency and AC power waveform mixed harmonics. The result shows that this algorithm has high precision and good stability.%  设计了电流比较仪式电桥的自动平衡算法,可测量电容器介质损耗角正切值及电容值。本算法是为了矫正试品电容器与标准电容器桥臂间的不平衡状态,通过测量标准电容器桥臂电流和检零计输出电压,输出匝数N2和增益β两个平衡参数,使检零计输出趋零。算法基于牛顿拉夫逊迭代方法,可由输出电压值修正得到精度更高的平衡参数,并用电桥平衡后的参数计算出正切值及电容值。本文测试了在电源频率偏差、频率波动、电源波形参杂谐波等多种条件下的性能,表明该算法精度高,稳定性好。

  3. Internal ultrasonic testing of steam generator tubes

    International Nuclear Information System (INIS)

    The ''in situ'' inspection of steam generator tubes uses generally Foucault currents before starting and along its life. This inspection aims at searching cracks and corrosion defects. The Foucault current method is quite badly adapted to ''closed crack'' detection, for it doesn't introduce neither resistivity or magnetic permeability variation, or lack of matter. More, it is sensible to the magnetic properties of the tube itself and to its environment (tubular or support plates). It is why, this first systematic inspection has to be completed by an ultrasonic one allowing to bring new elements in the uncertain cases. A device with an internal probe has been developed. It ''lights'' the tube wall with the aid of a transducer of which beam reflects on a mirror. Operating conditions are the same as for Foucault current testing, that is to say the probe moves inside the tube without rotation of the device (bent parts are excluded)

  4. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... YouTube Videos > NEI YouTube Videos: Amblyopia NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia ... of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia NEI on Twitter NEI on YouTube NEI ...

  5. NEI You Tube Videos: Amblyopia

    Science.gov (United States)

    ... NEI YouTube Videos > NEI YouTube Videos: Amblyopia NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration ... Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia NEI on Twitter NEI on YouTube ...

  6. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... NEI YouTube Videos > NEI YouTube Videos: Amblyopia NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration ... Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia NEI on Twitter NEI on YouTube ...

  7. 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

  8. Effect of Spacing between Coils in Pulsed Remote Field Eddy Current Testing for Ferromagnetic Tube%铁磁性管道脉冲远场涡流检测中线圈间距影响

    Institute of Scientific and Technical Information of China (English)

    喻星星; 付跃文; 蔚道祥; 徐进军; 江茫

    2015-01-01

    依据分析检测原理,对铁磁性管道脉冲远场涡流检测时激励线圈与接收线圈之间的间距对缺陷检测结果的影响进行试验研究. 给出了试验所得的检测线圈衰减曲线、检测灵敏度曲线以及感应电压剖面曲线. 对材质为J55,尺寸为?73. 8 mm × 5. 7 mm的油管进行检测试验,结果显示当线圈间距由60 mm逐步增加到210 mm时,检测线圈感应电压衰减曲线发生明显变化,缺陷检测灵敏度|Δu|/u由0. 35逐步增加到143,最高灵敏度对应的接收时间点前移2 511μs;但线圈间距增加到240 mm时,灵敏度|Δu|/u降为73. 试验结果表明:线圈间距为210 mm时,其检测灵敏度最佳. 该研究对脉冲远场涡流检测探头的设计具有参考价值.%Based on analysis of the principle, experiments are designed and performed to study the effect of the spacing between exciting coil and receiving coil on the detection sensitivity in pulsed remote field eddy current testing for ferromagnetic tube. Voltage decay curves of the receiving coil, sensitivity-time curves and time slices of voltage are given in the experiments. J55 oil well tube sample with a gauge of ?73. 8 mm × 5. 7 mm is inspected and the experimental results show that the increase of the spacing between the exciting coil and the receiving coil will cause several changes. When the spacing varies from 60 mm to 210 mm, voltage descending curves of the receiving coil have significant changes, detection sensitivity |Δu|/u varies from 0. 35 to 143 and the peak of detection sensitivity moves forward 2 511 μs, but detection sensitivity |Δu|/u falls to 73 when coil spacing increases to 240 mm. The experimental results show that the detection sensitivity is best when the distance reaches 210 mm. The results are of help to the design of pulsed remote field eddy current probe.

  9. Failure Analysis of Retired Steam Generator Tubings

    International Nuclear Information System (INIS)

    Since the first commercial operation of Kori-1 in 1978, 20 units of nuclear power plants are operated, and the it covers 40 % of total electricity in Korea as of 2008. A steam generator tube rupture incident occurred in the Ulchin unit 4 in 2002, which made the public sensitive to nuclear power plant. In order to keep the nuclear energy as a main energy source, the integrity of steam generator should be demonstrated. It is important to improve a flaw detection capability of the eddy current testing(ECT) in steam generator(SG) tubings in order to maintain the tube integrity. A quantified evaluation on the flaws on SG tubings, which is crucial for the tube integrity evaluation is not satisfactory. It is necessary to utilize the retired SG having various types of corrosion damages. In addition, an examination of pulled tube from Kori 1 retired steam generator will give us information about effectiveness of a remedial action(TiO2 addition) which was applied to mitigate ODSCC. A crack growth model is also needed to ensure a tube repair criteria for a next fuel cycle based on the ASME safety evaluation code, which has to meet a requirement that the flaws have to sustain under three times of normal operation pressure difference and 1.4 times of severe accident condition. In this project, hardware such as semi hot lab for pulled tube examination and modification of 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. The non-destructive and destructive examination of pulled tubes from Kori 1 retired steam generator were performed in the semi hot lab. An effect of remedial actions applied to Kori 1 retired steam generator, PWSCC trend and bulk water chemistry and crevice chemistry in Kori 1 were evaluated. An electrochemical decontamination technology for pulled tube was developed to reduce a radiation exposure and enhance

  10. Automatic Payroll Deposit System.

    Science.gov (United States)

    Davidson, D. B.

    1979-01-01

    The Automatic Payroll Deposit System in Yakima, Washington's Public School District No. 7, directly transmits each employee's salary amount for each pay period to a bank or other financial institution. (Author/MLF)

  11. Tubing weld cracking test

    International Nuclear Information System (INIS)

    A tubing weld cracking (TWC) test was developed for applications involving advanced austenitic alloys (such as modified 800H and 310HCbN). Compared to the Finger hot cracking test, the TWC test shows an enhanced ability to evaluate the crack sensitivity of tubing materials. The TWC test can evaluate the cracking tendency of base as well as filter materials. Thus, it is a useful tool for tubing suppliers, filler metal producers and fabricators

  12. X-ray tubes study and design

    CERN Document Server

    Sardari, D

    1990-01-01

    This thesis contain both theoretical and experimental works. Theoretical aspect includes X-Ray tubes case study and design principles, in the introduced design process, anode-cathode distance, vacuum needed, filament size, anode face angle and shape and size of focusing electrodes can be found. A method for specification of tungsten lager thickness on anode is also introduced. Using computer simulation, electron trajectory between cathode-anode is obtained, This work is presented in the first International Conference on Control and Modeling, Tehran, 1990. Experimental work contains manufacturing more than 10 tubes and test each of them. One of these tubes can with stand up to 50 KV. Filament can be heated by passing a 2.1 A current. In these conditions anode current is 1.2 m A. Using this tube, some radiographs have been taken.

  13. Cyclotron resonance in a cathode ray tube

    International Nuclear Information System (INIS)

    Absorption of the RF energy by the electron beam in a cathode ray tube due to the cyclotron resonance is described. The cathode ray tube is placed within a Helmholtz coils system supplied by a sawtooth current generator. In order to generate RF field and to detect RF absorption a gate dip-meter equipped with a FET transistor is used. The bias voltage variations of the FET transistors as a function of the magnetic field are recorded. The operating point of the cathode ray tube has been chosen so that the relaxation oscillations of the detection system can be observed. (authors)

  14. An Empirical Study on the Effect of Output Practice on Chinese EFL Speakers' Automaticity

    Institute of Scientific and Technical Information of China (English)

    杨雅君

    2015-01-01

    The improvement of automaticity in L2 acquisition leads to better fluency and less-consumed attentional resources. In China, current studies on automaticity are mostly theoretical. For a few empirical studies, automaticity in oral production is an issue that has not been explored yet. The significance of automaticity of syntax is manifested in its promotion of accuracy and fluency. Therefore, the author decided to carry out an empirical study to investigate Chinese EFL learners' oral automaticity of grammar.

  15. 脉冲涡流方法过油管检测套管横向裂缝研究%Research on Transverse Crack Detection in Casing through Tubing Using Pulsed Eddy Current Method

    Institute of Scientific and Technical Information of China (English)

    付跃文; 喻星星

    2014-01-01

    Transverse cracks are great menace to casing safety due to their highprobability to cause fracture. Transverse crack detection in casing through tubing with transverse probe using pulsed eddy current method is studied by finite element simulations and experiments. Distributions and variations of the eddy currents and magnetic fields in pipes and voltages of the receiving coil in different detection setups are given in the simulations. Simulation results show that highest eddy current intensity in casing wall does not appear in the zone which the transverse probe directly faces against but the zone which the axis of the transverse probe is parallel to. The greatest disturbance in the eddy current distribution is caused when the crack is parallel to the axis of the transverse probe. The properties of the magnetic field in the pipe are similar to those of the eddy current field. Thus it is explained why higher detection sensitivity is obtained when the axis of the transverse probe is parallel to the transverse crack rather than perpendicular to the crack. The experimental results agree well with the simulations and show that the detection sensitivity of the transverse probe to transverse crack is much higher when the axis of the probe is parallel to the crack than perpendicular to the crack.%油井套管横向裂缝是可能导致套管断裂的严重危害性缺陷。通过有限元仿真与实际试验,研究利用脉冲涡流检测技术使用横向探头通过油管检测套管的横向裂缝缺陷的问题。仿真给出不同检测方式的管道涡流分布、磁场分布及其变化,以及接收线圈的电压。从仿真结果可观察出,套管壁涡流最强的区域并非横向探头正对的区域,而是平行于横向探头轴线的区域。横向裂缝平行于横向探头轴线时对涡流场的扰动最大。磁场的分布及其变化规律与涡流场情况类同。据此可解释为何横向探头轴线平行于横向裂缝时检测灵敏

  16. Categorising YouTube

    OpenAIRE

    Thomas Mosebo Simonsen

    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...

  17. Steam generator tube performance

    International Nuclear Information System (INIS)

    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

  18. Effective string description of confining flux tubes

    Science.gov (United States)

    Brandt, Bastian B.; Meineri, Marco

    2016-08-01

    We review the current knowledge about the theoretical foundations of the effective string theory for confining flux tubes and the comparison of the predictions to pure gauge lattice data. A concise presentation of the effective string theory is provided, incorporating recent developments. We summarize the predictions for the spectrum and the profile/width of the flux tube and their comparison to lattice data. The review closes with a short summary of open questions for future research.

  19. Effective string description of confining flux tubes

    CERN Document Server

    Brandt, Bastian B

    2016-01-01

    We review the current knowledge about the theoretical foundations of the effective string theory for confining flux tubes and the comparison of the predictions to pure gauge lattice data. A concise presentation of the effective string theory is provided, incorporating recent developments. We summarize the predictions for the spectrum and the profile/width of the flux tube and their comparison to lattice data. The review closes with a short summary of open questions for future research.

  20. Establishment of a semi-biological phantom model for the study of the effect of dose reducing measures on radiation-induced DNA double strand breaks in CT using the example of risk organ based tube current modulation; Etablierung eines semibiologischen Phantommodells zur Untersuchung des Effekts dosisreduzierender Massnahmen auf strahleninduzierte DNA-Doppelstrangbrueche in der CT am Beispiel der risikoorganbasierten Roehrenstrommodulation

    Energy Technology Data Exchange (ETDEWEB)

    Sommer, Matthias

    2013-12-12

    The number of computed tomography (CT) examinations has been rising during the last decades. Therefore techniques for dose reduction receive increasing attention. Risk organ-based tube current modulation (RCM) in CT is a new approach and works by lowering the tube current, while the tube is in front of the patient's body. Therefore it should lead to a dose reduction for radiosensitive organs like the female breast, the eye lenses and the thyroid gland. Biological radiation effects cannot be estimated by physical-based dose measurements. γ-H2AX is a sensitive marker for the determination of x-ray induced DNA double-strand breaks (DSB). Hence the aim of this study was to establish a biological phantom model based on the γ-H2AX immunofluorescence microscopy method and to investigate the effect of RCM on radiation induced DNA damages. The γ-H2AX method is based on the phosphorylation of the histone variant H2AX. The phosphorylated histone γ-H2AX can be visualised using antibodies and is specific for radiation induced DSB. Blood lymphocytes from healthy volunteers, skin fibroblasts (LN) and mammary epithelial cells (HMEpC-p) were placed in different positions of an Alderson-phantom and exposed to x-rays using a 128-slice dual-source CT scanner. Standard head, neck and chest-CT scan protocols either with or without risk-organ based tube current modulation were used. RCM reduces the tube current to 20 percent at an angle of 130 degree anterior to the body, whereas tube current is increased at an angle of 230 degree posterior to the body. Afterwards cells were isolated, fixed on slides und stained with specific primary γ-H2AX antibodies and fluorescent secondary antibodies. Tiny green dots (named foci) can be detected and quantified with a fluorescence microscope and represent distinct DSB. Non-irradiated samples served as controls and CT-induced DSB were calculated by subtraction of pre- from post-exposure values. In this study a semibiological phantom model

  1. Effect of shot peening on steam generator tube cracking risks

    International Nuclear Information System (INIS)

    One of the main SG tube degradation modes in stress corrosion cracking on the primary side in the tube/tube plate roll transition zone. With a view to mitigating these cracking risks, on the 900 MWe PWR's plant, the SG inner tube walls were mechanically stress-relieved by shot peening. Between 1985 and 1988, periodic eddy current testing were performed during refuelling outages before and after the shot peening that allows to monitor the number and condition of affected tubes versus time in service. Statistical analysis were performed in order to test and quantify the effects of this treatment. (author). 3 figs., 2 refs

  2. Steam generator tube failures

    International Nuclear Information System (INIS)

    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

  3. Steam generator tube failures

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. A Position Estimation Method of the Control Rod Guide Tube with Matched Filters

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae C.; Seop, Jun H.; Choi, Yu R.; Kim, Jae H. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2005-07-01

    The risk that PWR guide tube support pins will crack has increased the necessity for the development of inspection methods and equipment. A special remote controlled manipulator has been widely used to inspect the guide tube support pins. In real situations, the manipulator is lowered into the internals pool and all the movements are monitored and controlled from a desk at the side of the pool. Because the diameter of the split pins is as small as 25mm, locating the ultrasonic transducer to the pins by a manual operation is a somewhat tedious task. To overcome this problem, a rail was placed on the bottom of the pool before the internals of the reactor vessel were lifted and lowered on to their stand. In this paper, we presented one method to eliminate this troublesome job by using a vision sensor already being used to monitor the manipulator's movements. There were some successful researches in designing controls for many dynamic systems in the case of their current position and where the desired trajectories are well defined. But a current position estimation of a robot and/or environmental objects is another problem that must be solved. A Matched filter algorithm is employed as a method for an automatic detection of the guide tube's and support pin's relative position to that of the robot. First, we construct two raw images corresponding to the guide tube and the support pin respectively. These are simply binary-valued image files that contain the shapes of each object. Next, we performed a 2-D FFT(fast fourier transform) on them. The transformed data files are the matched-filters to detect the presence of a guide tube and/or support pins and to estimate the positions of them. The cross correlation between the matched-filter and real input image can be calculated by the method of multiplying them followed by an inverse FFT. If the resulting value is greater than the pre-determined threshold value, we can conclude that there is at least one object

  5. Hologram recording tubes

    Science.gov (United States)

    Rajchman, J. H.

    1973-01-01

    Optical memories allow extremely large numbers of bits to be stored and recalled in a matter of microseconds. Two recording tubes, similar to conventional image-converting tubes, but having a soft-glass surface on which hologram is recorded, do not degrade under repeated hologram read/write cycles.

  6. Welding Tubes In Place

    Science.gov (United States)

    Meredith, R.

    1984-01-01

    Special welding equipment joins metal tubes that carry pressurized cyrogenic fluids. Equipment small enough to be used in confined spaces in which such tubes often mounted. Welded joints lighter in weight and more leak-proof than joints made with mechanical fittings.

  7. 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...

  8. Step-and-shoot prospectively ECG-gated versus retrospectively ECG-gated with tube current modulation coronary CT angiography using the 128-slice MDCT: comparison of image quality and radiation dose

    International Nuclear Information System (INIS)

    Background: Little is known regarding image quality and the required radiation dose for step-and-shoot and retrospective coronary computed tomography angiography (CCTA) with tube current modulation (TCM) in 128-slice multidetector CT (MDCT) coronary angiography. Purpose: To compare image quality and radiation dose in patients who underwent 128-slice MDCT by the step-and- shoot method with those in patients who underwent 128-slice MDCT with retrospective CCTA with TCM. Material and Methods: CCTA obtained with 128-slice MDCT was retrospectively evaluated in 160 patients. Two independent reviewers separately scored the subjective image quality of the coronary artery segments (1, excellent; 4, poor) for step-and-shoot (68, mean heart rate [HR]: 59.3±6.8) and retrospective CCTA with TCM (77, mean HR: 59.1±9.8). Interobserver variability was calculated. Effective radiation doses of both scan techniques were calculated with dose-length product. Results: There was good agreement for quality scores of coronary artery segment images between the independent reviewers (k=0.72). The number of coronary artery segments that could not be evaluated was 2.85% (27 of 947) in the step-and-shoot and 1.87% (20 of 1071) in retrospective CCTA with TCM. Image quality scores were not significantly different (P>.05). Mean patient radiation dose was 63% lower for step-and-shoot (1.94±0.70 mSv) than for retrospective CCTA with TCM (4.51±1.18 mSv) (P<0.0001). For patients who underwent step-and-shoot or retrospective CCTA with TCM, an average HR of 63.5 beats per minute was identified as the threshold for the prediction of non-diagnostic image quality for both protocols. There were no significant differences in the image quality of both methods between obese (body mass index [BMI≥25) and non-obese patients (BMI<25), but radiation doses were higher in the obesity group than in the non-obesity group for both methods. Conclusion: Both step-and-shoot and retrospective CCTA with TCM using 128

  9. Step-and-shoot prospectively ECG-gated versus retrospectively ECG-gated with tube current modulation coronary CT angiography using the 128-slice MDCT: comparison of image quality and radiation dose

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Dong Wook (Dept. of Family Medicine, Medial Research Institute, Pusan National Univ. Yangsan Hospital, School of Medicine, Gyeongsangnam-do, (Korea, Republic of)); Choo, Ki Seok; Baik, Seung Kug; Kim, Yong Woo; Jeon, Ung Bae (Dept. of Radiology, Medial Research Institute, Pusan National Univ. Yangsan Hospital, School of Medicine, Gyeongsangnam-do, (Korea, Republic of)), email: kschoo0618@naver.com; Kim, Jeong Soo (Dept. of Cardiology, Medial Research Institute, Pusan National Univ. Yangsan Hospital, School of Medicine, Gyeongsangnam-do (Korea, Republic of)); Lim, Soo Jin (Dept. of Cardiology, Kim Hae Joongang Hospital, Gyeongsangnam-do (Korea, Republic of))

    2011-02-15

    Background: Little is known regarding image quality and the required radiation dose for step-and-shoot and retrospective coronary computed tomography angiography (CCTA) with tube current modulation (TCM) in 128-slice multidetector CT (MDCT) coronary angiography. Purpose: To compare image quality and radiation dose in patients who underwent 128-slice MDCT by the step-and- shoot method with those in patients who underwent 128-slice MDCT with retrospective CCTA with TCM. Material and Methods: CCTA obtained with 128-slice MDCT was retrospectively evaluated in 160 patients. Two independent reviewers separately scored the subjective image quality of the coronary artery segments (1, excellent; 4, poor) for step-and-shoot (68, mean heart rate [HR]: 59.3+-6.8) and retrospective CCTA with TCM (77, mean HR: 59.1+-9.8). Interobserver variability was calculated. Effective radiation doses of both scan techniques were calculated with dose-length product. Results: There was good agreement for quality scores of coronary artery segment images between the independent reviewers (k=0.72). The number of coronary artery segments that could not be evaluated was 2.85% (27 of 947) in the step-and-shoot and 1.87% (20 of 1071) in retrospective CCTA with TCM. Image quality scores were not significantly different (P>.05). Mean patient radiation dose was 63% lower for step-and-shoot (1.94+-0.70 mSv) than for retrospective CCTA with TCM (4.51+-1.18 mSv) (P<0.0001). For patients who underwent step-and-shoot or retrospective CCTA with TCM, an average HR of 63.5 beats per minute was identified as the threshold for the prediction of non-diagnostic image quality for both protocols. There were no significant differences in the image quality of both methods between obese (body mass index [BMI>=25) and non-obese patients (BMI<25), but radiation doses were higher in the obesity group than in the non-obesity group for both methods. Conclusion: Both step-and-shoot and retrospective CCTA with TCM using 128

  10. Application of low tube current combined with lower contrast agent in the head and neck dual-source CT angiography%双源CT双低扫描在头颈部血管成像中的应用

    Institute of Scientific and Technical Information of China (English)

    李姝琪; 郭君武

    2015-01-01

    January 2015,120 patients undergoing head and neck computed tomography angiography (CTA) were randomly divided into groups A,B,C,D.Each group was given a different tube current and different dose of contrast agent and saline solution 50 ml.Group A received current 100 mA and contrast agent 50 ml,group B received current 100 mA and contrast agent 40 ml,group C received current 80 mA and contrast agent 50 ml,and group D received current 80 mA and contrast agent 40 ml.CT values of aortic arch,bilateral common carotid artery bifurcation,double sided M1 segment of middle cerebral artery,basilar artery enhanced degree of the straight sinus were measured in each group.Residual artifacts caused by contrast agent in brachiocephalic vein and subclavian vein were observed.5-score method was used to assess the quality of reconstructed image,and the radiation exposure dose was calculated.Results The mean effective dose was reduced by 29% in group C as compared with group A [(0.53±0.17) mGy vs.(0.74±0.04) mGy].There was no significant difference in developing strength in cerebral arteries angiography between group C and group A (P=0.247),but the inage noise was slightly larger in group C than group A,without significant differences (P=0.203).The average effective dose in group A was almost the same as that in group B [(0.74 ± 0.04) mGy vs.(0.73 ± 0.05) mGy].Structure display of cerebral arteries on CT volume rendering (VR) and multiplane reformation (MPR) images had no significant differences between group A and group B (P=0.114).The average effective dose in group C was almost the same as that in group D[(0.53 ± 0.17) mGy vs.(0.53 ±0.01) mGy].Structure display of cerebral arteries on CT volume rendering (VR) and muhiplane reformation (MPR) images had no significant differences between group C and group D (P=0.109).The mean effective dose was reduced by 28% in group D as compared with group B[(0.53±0.01)mGy vs.(0.73±0.05) mGy].There was no significant difference in

  11. Sensor-actuator coupled device for active tracheal tube using solid polymer electrolyte membrane

    Science.gov (United States)

    Ihara, Tadashi; Nakamura, Taro; Mukai, Toshiharu; Asaka, Kinji

    2007-04-01

    A sensor-actuator coupled device was developed using solid polymer electrolyte membrane (SPM) as an active tracheal tube for ventilator. Active tracheal tube is a novel type of tube for ventilator that removes patient's phlegm automatically upon sensing the narrowing of trachea by phlegm. This type of active tube is extremely useful in clinical settings as currently the sole measure to remove phlegm from patient's tube is to do it manually by a nurse every few hours. As SPM works both as a sensor and an actuator, an effective compact device was developed. SPM based sensor-actuator coupled device was fabricated with modified gold plating method. Prepared SPM was fixed as an array on a plastic pipe of diameter 22 mm and was connected to a ventilator circuit and driven by a ventilator with a volume control ventilation (VCV) mode. SPM was connected both to a sensing unit and an actuation unit. Generated voltage developed by the membrane with the setting of the maximum pressure from 5 cmH IIO to 20 cmH IIO was in order of several hundred μV. SPM sensor demonstrated a biphasic response to the ventilator flow. The sensor data showed nearly linearly proportional voltage development to the intra-tracheal pressure. The sensed signal was filtered and digitized with an A/D converting unit on a PC board. A real time operating program was used to detect the sensed signal that indicates the narrowing of trachea. The program then activated a driving signal to control the actuation of the membrane. The signal was sent to a D/A converting unit. The output of the D/A unit was sent to an amplifier and the galvanostat unit which drives the membrane with constant current regardless of the change in the load. It was demonstrated that the sensor-actuator unit detects the narrowing of trachea within several hundreds milli-seconds and responds by actuating the same membrane with the driving voltage of 3-4 V and driving current of several hundred milli-ampere for each membrane. SPM array

  12. Eddy current testing

    Energy Technology Data Exchange (ETDEWEB)

    Song, Sung Jin; Lee, Hyang Beom; Kim, Young Hwan [Soongsil Univ., Seoul (Korea, Republic of); Shin, Young Kil [Kunsan Univ., Gunsan (Korea, Republic of)

    2004-02-15

    Eddy current testing has been widely used for non destructive testing of steam generator tubes. In order to retain reliability in ECT, the following subjects were carried out in this study: numerical modeling and analysis of defects by using BC and RPC probes in SG tube, preparation of absolute coil impedance plane diagram by FEM. Signal interpretation of the eddy current signals obtained from nuclear power plants.

  13. Robotic Tube-Gap Inspector

    Science.gov (United States)

    Gilbert, Jeffrey L.; Gutow, David A.; Maslakowski, John E.

    1993-01-01

    Robotic vision system measures small gaps between nearly parallel tubes. Robot-held video camera examines closely spaced tubes while computer determines gaps between tubes. Video monitor simultaneously displays data on gaps.

  14. Sleeving repair of heat exchanger tubes

    International Nuclear Information System (INIS)

    Defective heat exchanger tubes can be repaired using techniques that do not involve the cost and schedule penalties of component replacement. FTI's years of experience repairing steam generator tubes have been successfully applied to heat exchangers. Framatome Technologies heat exchanger sleeves can bridge defective areas of the heat exchanger tubes, sleeves have been designed to repair typical heat exchanger tube defects caused by excessive tube vibration, stress corrosion cracking, pitting or erosion. By installing a sleeve, the majority of the tube's heat transfer and flow capacity is maintained and the need to replace the heat exchanger can be delayed or eliminated. Both performance and reliability are improved. FTI typically installs heat exchanger tube sleeves using either a roll expansion or hydraulic expansion process. While roll expansion of a sleeve can be accomplished very quickly, hydraulic expansion allows sleeves to be installed deep within a tube where a roll expander cannot reach. Benefits of FTI's heat exchanger tube sleeving techniques include: - Sleeves can be positioned any where along the tube length, and for precise positioning of the sleeve eddy current techniques can be employed. - Varying sleeve lengths can be used. - Both the roll and hydraulic expansion processes are rapid and both produce joints that do not require stress relief. - Because of low leak rates and speed of installations, sleeves can be used to preventatively repair likely-to-fail tubes. - Sleeves can be used for tube stiffening and to limit leakage through tube defects. - Because of installation speed, there is minimal impact on outage schedules and budgets. FTI's recently installed heat exchanger sleeving at the Kori-3 Nuclear Power Station in conjunction with Korea Plant Service and Engineering Co., Ltd. The sleeves were installed in the 3A and 3B component cooling water heat exchangers. A total of 859 tubesheet and 68 freespan sleeves were installed in the 3A heat

  15. A domain-based approach for retrieving trustworthy health videos from YouTube.

    Science.gov (United States)

    Karlsen, Randi; Borrás Morell, Jose Enrique; Fernández Luque, Luis; Traver Salcedo, Vicente

    2013-01-01

    Health information retrieval and YouTube can be used as powerful tools to improve user's health knowledge. However, YouTube videos must be carefully analysed in order to avoid misleading, inaccurate, obsolete and incorrect health content. We present an approach for re-ranking health videos obtained from YouTube, called Domain-based ranking. Our system automatically identifies videos coming from trusted sources (channels), such as hospitals and health organizations, and re-ranks YouTube results so that such videos are presented first in the ranking list. Video and channel metadata are used to automatically determine if a video is provided by a trusted source. The approach is tested and results show that the amount of relevant and reliable videos ranked within top-10 increase when using Domain-based ranking, compared with the original YouTube ranking.

  16. Demonstration for the Applicability of the EPRI ETSS on the SG Tube Wear Defects Formed at the Tube Support Structure

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Ki Seok; Cheon, Keun Young; Nam, Min Woo [Korea Hydro and Nuclear Power Co. Ltd, Daejeon (Korea, Republic of); Min, Kyong Mahn [Universal Monitoring and Inspection Inc., Daejeon (Korea, Republic of)

    2013-10-15

    In this paper, the authorized EPRI ETSS 27906.2 applied to the detection of tapered wear volumetric indications and depth sizing within the free span area, loose part not present was reviewed and applied to the site SG tubes for getting the actual value of the wear depth and providing structural integrity interpretation based on engineering evaluation. The experiment to demonstrate the applicability of EPRI ETSS was performed by the employment of the newly prepared STD tube and resulted in ensuring the effectiveness and equivalency of the EPRI ETSS as well. The authorized EPRI ETSS 27906.2 for getting the actual value of the wear depth and providing structural integrity interpretation based on engineering evaluation was reviewed and applied to the site SG tubes. The testing results were reviewed with the influences of SG tube material and the support structure. The impact of the tube materials was insignificant and that of the tube support structure showed somewhat conservative results. The testing resulted in successful demonstration of applicability of the EPRI ETSS on the SG tube wear defects at the tube support. One of the major flaw mechanisms detected in the currently operating domestic OPR-1000 pressurized water reactors(PWR's) steam generator(SG) tubes is wear defect. In general, wear defect has been constantly detected in the upper tube bundle imposed to the flow induced vibration interaction between tube and its support structure, and the quantity of the affected tubes has also shown the tendency to increase as plant operation life is added. In order to take appropriate measures and maintain the structural integrity for the SG tubes, wear defect is currently categorized as active damage mechanism and the tubes containing 40% or greater wear depth of the nominal tube wall thickness shall be plugged per SGMP(SG Management Program) Recently, a fairly large amplitude of wear defects on the Batwing(BW), one of the upper tube support structures in the SG

  17. Neuroanatomical automatic segmentation in brain cancer patients

    OpenAIRE

    D’Haese, P.; Niermann, K; Cmelak, A.; Donnelly, E.; Duay, V.; Li, R; Dawant, B.

    2003-01-01

    Conformally prescribed radiation therapy for brain cancer requires precisely defining the target treatment area, as well as delineating vital brain structures which must be spared from radiotoxicity. The current clinical practice of manually segmenting brain structures can be complex and exceedingly time consuming. Automatic computeraided segmentation methods have been proposed to increase efficiency and reproducibility in developing radiation treatment plans. Previous studies have establishe...

  18. ASAM: Automatic architecture synthesis and application mapping

    DEFF Research Database (Denmark)

    Jozwiak, Lech; Lindwer, Menno; Corvino, Rosilde;

    2013-01-01

    This paper focuses on mastering the automatic architecture synthesis and application mapping for heterogeneous massively-parallel MPSoCs based on customizable application-specific instruction-set processors (ASIPs). It presents an overview of the research being currently performed in the scope of...

  19. The Choking Game on YouTube

    Directory of Open Access Journals (Sweden)

    Ellen K. Defenderfer MS

    2016-03-01

    Full Text Available The choking game (TCG is an adolescent activity in which asphyxiation is used to obtain a “high,” occasionally resulting in seizures or death. A plethora of TCG information is available through YouTube, though this content has not been evaluated recently. The current study described TCG as portrayed in YouTube videos and compared views and ratings of TCG videos to unrelated videos. The TCG videos demonstrated diverse methods of asphyxiation, with a minority showing injury to the participants. TCG videos were less likely to be commented on or rated positively than non–choking game videos. TCG prevention videos differed significantly from actual TCG videos in the way they depicted the social context of TCG. Thus, TCG videos are accessible through YouTube, but the prevention materials available on YouTube are not accurate or representative. Accurate and educational online prevention materials should be created to decrease the occurrence of TCG.

  20. Automatic utilities auditing

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Colin Boughton [Energy Metering Technology (United Kingdom)

    2000-08-01

    At present, energy audits represent only snapshot situations of the flow of energy. The normal pattern of energy audits as seen through the eyes of an experienced energy auditor is described. A brief history of energy auditing is given. It is claimed that the future of energy auditing lies in automatic meter reading with expert data analysis providing continuous automatic auditing thereby reducing the skill element. Ultimately, it will be feasible to carry out auditing at intervals of say 30 minutes rather than five years.

  1. Automatic Camera Control

    DEFF Research Database (Denmark)

    Burelli, Paolo; Preuss, Mike

    2014-01-01

    Automatically generating computer animations is a challenging and complex problem with applications in games and film production. In this paper, we investigate howto translate a shot list for a virtual scene into a series of virtual camera configurations — i.e automatically controlling the virtual...... camera. We approach this problem by modelling it as a dynamic multi-objective optimisation problem and show how this metaphor allows a much richer expressiveness than a classical single objective approach. Finally, we showcase the application of a multi-objective evolutionary algorithm to generate a shot...

  2. Pressure tube type reactor

    International Nuclear Information System (INIS)

    Heretofore, a pressure tube type reactor has a problem in that the evaluation for the reactor core performance is complicate and no sufficient consideration is made for the economical property, to increase the size of a calandria tank and make the cost expensive. Then, in the present invention, the inner diameter of a pressure tube is set to greater than 50% of the lattice gap in a square lattice like arrangement, and the difference between the inner and the outer diameters of the calandria tube is set smaller than 20% of the lattice gap. Further, the inner diameter of the pressure tube is set to greater than 40% and the difference between the inner and the outer diameters of the calandria tube is set smaller than 30% of the lattice gap in a triangle lattice arrangement. Then, heavy water-to-fuel volume ratio can be determined appropriately and the value for the coolant void coefficient is made more negative side, to improve the self controllability inherent to the reactor. In particular, when 72 to 90 fuel rods are arranged per one pressure tube, the power density per one fuel rod is can be increased by about twice. Accordingly, the number of the pressure tubes can be reduced about to one-half, thereby enabling to remarkably decrease the diameter of the reactor core and to reduce the size of the calandria, which is economical. (N.H.)

  3. Integrating YouTube into the nursing curriculum.

    Science.gov (United States)

    Sharoff, Leighsa

    2011-08-17

    Nurse educators need to be innovative, stimulating, and engaging as they teach future nursing professionals. The use of YouTube in nursing education classes provides an easy, innovative, and user-friendly way to engage today's nursing students. YouTube presentations can be easily adapted into nursing courses at any level, be it a fundamentals course for undergraduate students or a theoretical foundations course for graduate students. In this article I will provide information to help educators effectively integrate YouTube into their course offerings. I will start by reviewing the phenomenon of social networking. Next I will discuss challenges and strategies related to YouTube learning experiences, after which I will share some of the legal considerations in using YouTube. I will conclude by describing how to engage students via YouTube and current research related to YouTube.

  4. Isolated Fallopian Tube Torsion

    Directory of Open Access Journals (Sweden)

    S. Kardakis

    2013-01-01

    Full Text Available Isolated torsion of the Fallopian tube is a rare gynecological cause of acute lower abdominal pain, and diagnosis is difficult. There are no pathognomonic symptoms; clinical, imaging, or laboratory findings. A preoperative ultrasound showing tubular adnexal masses of heterogeneous echogenicity with cystic component is often present. Diagnosis can rarely be made before operation, and laparoscopy is necessary to establish the diagnosis. Unfortunately, surgery often is performed too late for tube conservation. Isolated Fallopian tube torsion should be suspected in case of acute pelvic pain, and prompt intervention is necessary.

  5. Embryonic Heart Morphogenesis from Confocal Microscopy Imaging and Automatic Segmentation

    Directory of Open Access Journals (Sweden)

    Hongda Mao

    2013-01-01

    Full Text Available Embryonic heart morphogenesis (EHM is a complex and dynamic process where the heart transforms from a single tube into a four-chambered pump. This process is of great biological and clinical interest but is still poorly understood for two main reasons. On the one hand, the existing imaging modalities for investigating EHM suffered from either limited penetration depth or limited spatial resolution. On the other hand, current works typically adopted manual segmentation, which was tedious, subjective, and time consuming considering the complexity of developing heart geometry and the large size of images. In this paper, we propose to utilize confocal microscopy imaging with tissue optical immersion clearing technique to image the heart at different stages of development for EHM study. The imaging method is able to produce high spatial resolution images and achieve large penetration depth at the same time. Furthermore, we propose a novel convex active contour model for automatic image segmentation. The model has the ability to deal with intensity fall-off in depth which is characterized by confocal microscopy images. We acquired the images of embryonic quail hearts from day 6 to day 14 of incubation for EHM study. The experimental results were promising and provided us with an insight view of early heart growth pattern and also paved the road for data-driven heart growth modeling.

  6. A New Ultrasonic Inspection System for Non-Destructive Examination of Precision Tubes

    DEFF Research Database (Denmark)

    Gundtoft, Hans Erik; Agerup, C. C.; Nielsen, T.

    1977-01-01

    different combinations of the modules in the system. This paper describes evaluation and development work on this system that has been carried out, based on practical experience with tube inspection. Also discussed is the influence of various modifications to the system on stability and accuracy during......The Risø/HV Tube Inspection System is designed for fast automatic inspection of the dimensions of and defects in precision tubes. The system is based upon a rotating water chamber with eight ultrasonic transducers. Tube handling and evaluation of the results can be performed in various ways using...

  7. Automatic malware analysis an emulator based approach

    CERN Document Server

    Yin, Heng

    2012-01-01

    Malicious software (i.e., malware) has become a severe threat to interconnected computer systems for decades and has caused billions of dollars damages each year. A large volume of new malware samples are discovered daily. Even worse, malware is rapidly evolving becoming more sophisticated and evasive to strike against current malware analysis and defense systems. Automatic Malware Analysis presents a virtualized malware analysis framework that addresses common challenges in malware analysis. In regards to this new analysis framework, a series of analysis techniques for automatic malware analy

  8. Unification of automatic target tracking and automatic target recognition

    Science.gov (United States)

    Schachter, Bruce J.

    2014-06-01

    The subject being addressed is how an automatic target tracker (ATT) and an automatic target recognizer (ATR) can be fused together so tightly and so well that their distinctiveness becomes lost in the merger. This has historically not been the case outside of biology and a few academic papers. The biological model of ATT∪ATR arises from dynamic patterns of activity distributed across many neural circuits and structures (including retina). The information that the brain receives from the eyes is "old news" at the time that it receives it. The eyes and brain forecast a tracked object's future position, rather than relying on received retinal position. Anticipation of the next moment - building up a consistent perception - is accomplished under difficult conditions: motion (eyes, head, body, scene background, target) and processing limitations (neural noise, delays, eye jitter, distractions). Not only does the human vision system surmount these problems, but it has innate mechanisms to exploit motion in support of target detection and classification. Biological vision doesn't normally operate on snapshots. Feature extraction, detection and recognition are spatiotemporal. When vision is viewed as a spatiotemporal process, target detection, recognition, tracking, event detection and activity recognition, do not seem as distinct as they are in current ATT and ATR designs. They appear as similar mechanism taking place at varying time scales. A framework is provided for unifying ATT and ATR.

  9. Automatic Complexity Analysis

    DEFF Research Database (Denmark)

    Rosendahl, Mads

    1989-01-01

    One way to analyse programs is to to derive expressions for their computational behaviour. A time bound function (or worst-case complexity) gives an upper bound for the computation time as a function of the size of input. We describe a system to derive such time bounds automatically using abstract...

  10. Kinking of medical tubes.

    Science.gov (United States)

    Ingles, David

    2004-05-01

    The phenomenon of kinking in medical tubing remains a problem for some applications, particularly critical ones such as transporting gasses or fluids. Design features are described to prevent its occurrence.

  11. Transport driven by spatially modulated noise in a periodic tube

    Energy Technology Data Exchange (ETDEWEB)

    Ai Baoquan [Institute for Condensed Matter Physics, School of Physics and Telecommunication Engineering and Laboratory of Photonic Information Technology, South China Normal University, 510006 Guangzhou (China); Liu Lianggang [The Faculty of Information Technology, Macau University of Science and Technology, Macao (China)

    2007-07-04

    This paper investigates a three-dimensional periodic tube driven by spatially modulated Gaussian white noise. We derive an analytical expression for the net current by introducing entropic barriers. It is found that the phase shift between the entirely symmetric tube and noise modulation can break the symmetry of the generalized potential and induce directed transport. The sign of the current is determined by the phase shift. The current is a peaked function of the bottleneck radius. The interplay between the asymmetric tube and noise modulation can also induce a net current.

  12. ABSTRACTS WELDEL PIPE AND TUBE

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    ABSTRACTS WELDEL PIPE AND TUBE Vol.24 No.3 May.2001 Huang Jingan(1) Strengthen, Intercourse, Coordination and Promote the Development Together Liang Aiyu(11) The Production and the Development of the Water supply pipe for City Construction From the aspects of the quality, appearance, environment protection, economic analysis etc., This article evaluates the galvanized pipe, plastic steel complex pipe, plastic aluminum pipe, stainless pipe for city water supply. In accordance with the requirements of the city construction programming and development, it is considered that the plastic aluminum pipe and plastic steel pipe instead of galvanization pipe is the trend of the development. The author also gives some constructive proposals for reference. Subject Terms:galvanized pipe complex pipe stainless pipe city water supply evaluation Zhao Rongbin,Li Guangjun(14) The TIG welding of Protected Tantalum-pipe for sheathed thermocouples used in corrosive environment The protected Tantalum-pipe welding of sheathed therocouples was investigated by TIG. The welding process and its key parameters were introduced. Welding quality influenced by processing was discussed. Subject Terms:welding protected Tantalum-pipe corrosion He Defu et al(18) Design and Research for An Automatic MIG Welding Machine of Catalyst Converter of Automobile Two different schemes for automatic MIG welding of catalyst converter of automobile have been compared and analysed. A design of automatic MIG welding machine used for catalyst converter of automobile has been suggested in this paper. Subject Terms:environmental protection automobile tri-catalyst converter MIG welding automatic welding PLC Fang Chucai(24) Cold Crack Analysis of Low Alloy High Strength Steel Weld Seam Heat Affected Area During the welding of low alloy high strength (X65 and above), the fine crack occurs in the weld (especially inner weld) and the low plastic hard brickle structure occurs in the Heat Affected Area (HAZ) sometime. This

  13. Power vacuum tubes handbook

    CERN Document Server

    Whitaker, Jerry

    2012-01-01

    Providing examples of applications, Power Vacuum Tubes Handbook, Third Edition examines the underlying technology of each type of power vacuum tube device in common use today. The author presents basic principles, reports on new development efforts, and discusses implementation and maintenance considerations. Supporting mathematical equations and extensive technical illustrations and schematic diagrams help readers understand the material. Translate Principles into Specific Applications This one-stop reference is a hands-on guide for engineering personnel involved in the design, specification,

  14. Working session 2: Tubing inspection

    Energy Technology Data Exchange (ETDEWEB)

    Guerra, J. [Tecnatom, S.A. San Sebastian de los Reyes, Madrid (Spain); Tapping, R.L. [AECL, Chalk River, Ontario (Canada)

    1997-02-01

    This session was attended by delegates from 10 countries, and four papers were presented. A wide range of issues was tabled for discussion. Realizing that there was limited time available for more detailed discussion, three topics were chosen for the more detailed discussion: circumferential cracking, performance demonstration (to focus on POD and sizing), and limits of methods. Two other subsessions were organized: one dealt with some challenges related to the robustness of current inspection methods, especially with respect to leaving cracked tubes in service, and the other with developing a chart of current NDE technology with recommendations for future development. These three areas are summarized in turn, along with conclusions and/or recommendations. During the discussions there were four presentations. There were two (Canada, Japan) on eddy current probe developments, both of which addressed multiarray probes that would detect a range of flaws, one (Spain) on circumferential crack detection, and one (JRC, Petten) on the recent PISC III results.

  15. Aeronautical tubes and pipes

    Science.gov (United States)

    Beauclair, N.

    1984-12-01

    The main and subcomponent French suppliers of aircraft tubes and pipes are discussed, and the state of the industry is analyzed. Quality control is essential for tubes with regard to their i.d. and metallurgical compositions. French regulations do not allow welded seam tubes in hydraulic circuits unless no other form is available, and then rustproofed steel must be installed. The actual low level of orders for any run of tubes dictates that the product is only one of several among the manufacturers' line. Automation, both in NDT and quality control, assures that the tubes meet specifications. A total of 10 French companies participate in the industry, serving both civil and military needs, with some companies specializing only in titanium, steel, or aluminum materials. Concerns wishing to enter the market must upgrade their equipment to meet the higher aeronautical specifications and be prepared to furnish tubes and pipes that serve both functional and structural purposes simultaneously. Additionally, pipe-bending machines must also perform to tight specifications. Pipes can range from 0.2 mm exterior diameter to 40 mm, with wall thicknesses from 0.02 mm to 3 mm. A chart containing a list of manufacturers and their respective specifications and characteristics is presented, and a downtrend in production with reduction of personnel is noted.

  16. Clearing obstructed feeding tubes.

    Science.gov (United States)

    Marcuard, S P; Stegall, K L; Trogdon, S

    1989-01-01

    This is a report of an in vitro study evaluating the ability of six solutions to dissolve clotted enteral feeding, which can cause feeding tube occlusion. The following clotted enteral feeding products were tested: Ensure Plus, Ensure Plus with added protein (Promod 20 g/liter), Osmolite, Enrich, and Pulmocare. Clot dissolution was then tested by adding Adolf's Meat Tenderizer, Viokase, Sprite, Pepsi, Coke, or Mountain Dew. Distilled water served as control. Dissolution score for each mixture was assessed blindly. Best dissolution was observed with Viokase in pH 7.9 solution (p less than 0.01). Similar results were obtained when feeding tube patency was restored in eight in vitro occluded feeding tubes (Dobbhoff, French size 8) by using first Pepsi (two/eight successful) and then Viokase in pH 7.9 (six/six successful). We also report our experience in the first 10 patients with occluded feeding tubes using this Viokase solution injected through a Drum catheter into the feeding tube. In seven patients, this method proved to be successful, and the reasons for failure in three patients include a knotted tube, impacted tablet powder, and a formula clot fo 24 hr duration and 45 cm in length. PMID:2494372

  17. A gas laser tube

    Energy Technology Data Exchange (ETDEWEB)

    Tetsuo, F.; Tokhikhide, N.

    1984-04-19

    A gas laser tube is described in which contamination of the laser gas mixture by the coolant is avoided, resulting in a longer service life of the mirrors. The holder contains two tubes, one inside the other. The laser gas mixture flows through the internal tube. An electrode is fastened to the holder. The coolant is pumped through the slot between the two tubes, for which a hole is cut into the holder. The external tube has a ring which serves to seal the cavity containing the coolant from the atmosphere. The internal tube has two rings, one to seal the laser gas mixture and the other to seal the coolant. A slot is located between these two rings, which leads to the atmosphere (the atmosphere layer). With this configuration, the degradation of the sealing properties of the internal ring caused by interaction with the atmospheric layer is not reflected in the purity of the laser gas mixture. Moreover, pollution of the mirrors caused by the penetration of the coolant into the cavity is eliminated.

  18. Automatic and strategic processes in advertising effects

    DEFF Research Database (Denmark)

    Grunert, Klaus G.

    1996-01-01

    are at variance with current notions about advertising effects. For example, the att span problem will be relevant only for strategic processes, not for automatic processes, a certain amount of learning can occur with very little conscious effort, and advertising's effect on brand evaluation may be more stable......Two kinds of cognitive processes can be distinguished: Automatic processes, which are mostly subconscious, are learned and changed very slowly, and are not subject to the capacity limitations of working memory, and strategic processes, which are conscious, are subject to capacity limitations......, and can easily be adapted to situational circumstances. Both the perception of advertising and the way advertising influences brand evaluation involves both processes. Automatic processes govern the recognition of advertising stimuli, the relevance decision which determines further higher-level processing...

  19. Fault injection system for automatic testing system

    Institute of Scientific and Technical Information of China (English)

    王胜文; 洪炳熔

    2003-01-01

    Considering the deficiency of the means for confirming the attribution of fault redundancy in the re-search of Automatic Testing System(ATS) , a fault-injection system has been proposed to study fault redundancyof automatic testing system through compurison. By means of a fault-imbeded environmental simulation, thefaults injected at the input level of the software are under test. These faults may induce inherent failure mode,thus bringing about unexpected output, and the anticipated goal of the test is attained. The fault injection con-sists of voltage signal generator, current signal generator and rear drive circuit which are specially developed,and the ATS can work regularly by means of software simulation. The experimental results indicate that the faultinjection system can find the deficiency of the automatic testing software, and identify the preference of fault re-dundancy. On the other hand, some soft deficiency never exposed before can be identified by analyzing the tes-ting results.

  20. Stability of spiral welded tubes in Quay Walls

    OpenAIRE

    Gresnigt, A. M.; van Es, S.H.J.

    2013-01-01

    A European research project (RFCS) has started to provide economic and safe guidance for the design of spirally welded tubes in combined walls. The main motivation for this project called COMBITUBE is that the current Eurocode 3 regulations for tubes in quay walls lead to uneconomic designs, because of poor local buckling design rules for these tubes. Because the most important load in quay walls is bending due to earth load, economic design implies a high diameter to wall thickness ratio. Fo...

  1. Automated Identification and Reconstruction of YouTube Video Access

    Directory of Open Access Journals (Sweden)

    Jonathan Patterson

    2012-06-01

    Full Text Available YouTube is one of the most popular video-sharing websites on the Internet, allowing users to upload, view and share videos with other users all over the world. YouTube contains many different types of videos, from homemade sketches to instructional and educational tutorials, and therefore attracts a wide variety of users with different interests. The majority of YouTube visits are perfectly innocent, but there may be circumstances where YouTube video access is related to a digital investigation, e.g. viewing instructional videos on how to perform potentially unlawful actions or how to make unlawful articles.When a user accesses a YouTube video through their browser, certain digital artefacts relating to that video access may be left on their system in a number of different locations. However, there has been very little research published in the area of YouTube video artefacts.The paper discusses the identification of some of the artefacts that are left by the Internet Explorer web browser on a Windows system after accessing a YouTube video. The information that can be recovered from these artefacts can include the video ID, the video name and possibly a cached copy of the video itself. In addition to identifying the artefacts that are left, the paper also investigates how these artefacts can be brought together and analysed to infer specifics about the user’s interaction with the YouTube website, for example whether the video was searched for or visited as a result of a suggestion after viewing a previous video.The result of this research is a Python based prototype that will analyse a mounted disk image, automatically extract the artefacts related to YouTube visits and produce a report summarising the YouTube video accesses on a system.

  2. Laser Welding Of Finned Tubes Made Of Austenitic Steels

    OpenAIRE

    Stolecki M.; Bijok H.; Kowal Ł.; Adamiec J.

    2015-01-01

    This paper describes the technology of welding of finned tubes made of the X5CrNi1810 (1.4301) austenitic steel, developed at Energoinstal SA, allowing one to get high quality joints that meet the requirements of the classification societies (PN-EN 15614), and at the same time to significantly reduce the manufacturing costs. The authors described an automatic technological line equipped with a Trumph disc laser and a tube production technological process. To assess the quality of the joints, ...

  3. Caring for Tube-Fed Children: A Review of Management, Tube Weaning, and Emotional Considerations.

    Science.gov (United States)

    Edwards, Sarah; Davis, Ann M; Bruce, Amanda; Mousa, Hayat; Lyman, Beth; Cocjin, Jose; Dean, Kelsey; Ernst, Linda; Almadhoun, Osama; Hyman, Paul

    2016-07-01

    Enteral nutrition is the practice of delivering nutrition to the gut either orally or through a tube or other device. Many children are reliant on enteral feedings to either supplement their nutrition or as a complete source of their nutrition. Managing children on tube feedings requires a team of providers to work through such dilemmas as feeding schedules, weaning from tube feeding, sensory implications of tube feeding, treatment of pain or nausea associated with eating, oral-motor issues, and behavioral issues in the child and family. The purpose of the current review is to summarize the multidisciplinary aspects of enteral feeding. The multidisciplinary team consists of a variable combination of an occupational therapist, speech-language pathologist, gastroenterologist, psychologist, nurse, pharmacist, and dietitian. Children who have minimal oral feeding experience and are fed via a nasogastric or gastrostomy tube often develop oral aversions. Limited data support that children with feeding disorders are more likely to have sensory impairment and that early life pain experiences contribute to feeding refusal. There are inpatient and outpatient programs for weaning patients from tube feeding to eating. The parent-child interaction is an important part of the assessment and treatment of the tube-fed child. This review also points out many information gaps, including data on feeding schedules, blenderized tube feedings, the best methods for weaning children off enteral feedings, the efficacy of chronic pain medications with tube-fed children, and, finally, the necessity of the assessment of parental stress among all parents of children who are tube fed. PMID:25791833

  4. Automatic patient dose registry and clinical audit on line for mammography

    International Nuclear Information System (INIS)

    The use of automatic registry systems for patient dose in digital mammography allows clinical audit and patient dose analysis of the whole sample of individual mammography exposures while fulfilling the requirements of the European Directives and other international recommendations. Further parameters associated with radiation exposure (tube voltage, X-ray tube output and HVL values for different kVp and target/filter combinations, breast compression, etc.) should be periodically verified and used to evaluate patient doses. This study presents an experience in routine clinical practice for mammography using automatic systems. (authors)

  5. Automatic trend estimation

    CERN Document Server

    Vamos¸, C˘alin

    2013-01-01

    Our book introduces a method to evaluate the accuracy of trend estimation algorithms under conditions similar to those encountered in real time series processing. This method is based on Monte Carlo experiments with artificial time series numerically generated by an original algorithm. The second part of the book contains several automatic algorithms for trend estimation and time series partitioning. The source codes of the computer programs implementing these original automatic algorithms are given in the appendix and will be freely available on the web. The book contains clear statement of the conditions and the approximations under which the algorithms work, as well as the proper interpretation of their results. We illustrate the functioning of the analyzed algorithms by processing time series from astrophysics, finance, biophysics, and paleoclimatology. The numerical experiment method extensively used in our book is already in common use in computational and statistical physics.

  6. Automatic Program Reports

    OpenAIRE

    Lígia Maria da Silva Ribeiro; Gabriel de Sousa Torcato David

    2007-01-01

    To profit from the data collected by the SIGARRA academic IS, a systematic setof graphs and statistics has been added to it and are available on-line. Thisanalytic information can be automatically included in a flexible yearly report foreach program as well as in a synthesis report for the whole school. Somedifficulties in the interpretation of some graphs led to the definition of new keyindicators and the development of a data warehouse across the university whereeffective data consolidation...

  7. Automatic food decisions

    DEFF Research Database (Denmark)

    Mueller Loose, Simone

    Consumers' food decisions are to a large extent shaped by automatic processes, which are either internally directed through learned habits and routines or externally influenced by context factors and visual information triggers. Innovative research methods such as eye tracking, choice experiments...... and food diaries allow us to better understand the impact of unconscious processes on consumers' food choices. Simone Mueller Loose will provide an overview of recent research insights into the effects of habit and context on consumers' food choices....

  8. Automatic Differentiation Variational Inference

    OpenAIRE

    Kucukelbir, Alp; Tran, Dustin; Ranganath, Rajesh; Gelman, Andrew; Blei, David M.

    2016-01-01

    Probabilistic modeling is iterative. A scientist posits a simple model, fits it to her data, refines it according to her analysis, and repeats. However, fitting complex models to large data is a bottleneck in this process. Deriving algorithms for new models can be both mathematically and computationally challenging, which makes it difficult to efficiently cycle through the steps. To this end, we develop automatic differentiation variational inference (ADVI). Using our method, the scientist on...

  9. Automatic summarising factors and directions

    CERN Document Server

    Jones, K S

    1998-01-01

    This position paper suggests that progress with automatic summarising demands a better research methodology and a carefully focussed research strategy. In order to develop effective procedures it is necessary to identify and respond to the context factors, i.e. input, purpose, and output factors, that bear on summarising and its evaluation. The paper analyses and illustrates these factors and their implications for evaluation. It then argues that this analysis, together with the state of the art and the intrinsic difficulty of summarising, imply a nearer-term strategy concentrating on shallow, but not surface, text analysis and on indicative summarising. This is illustrated with current work, from which a potentially productive research programme can be developed.

  10. Steam generator tube fretting - Darlington NGS experience

    International Nuclear Information System (INIS)

    Early signs of tube fretting in the U-bend region of Darlington NGS Steam Generators (SGs) were observed during the metallurgical examination of the removed peripheral tube U-bend sections from Unit 4 SG3 in 1995. During a forced outage in early 1998, Eddy Current (ECT) tube inspections in Unit 2 SG4 revealed more extensive fretting of the tubes at the U-bend AVB support locations. Subsequently in the period of 1999-2001, planned Eddy Current tube inspections have been carried out in all units covering all SGs. These inspections have revealed considerable U-bend tube fretting with a number of these fret depths in excess of 40% tw. Evaluation of the ECT and UT results, in conjunction with engineering assessment of the SG design and construction, have determined tube fretting in the U-bend region as an active and reportable degradation mechanism in these SGs. To date, all 16 Darlington SGs have undergone a major ECT inspection. In these inspections as a minimum, the identified fretting region of the U-bend has been adequately covered. Analyses of the inspection results have been carried out to provide trends and observations of the fretting in the U-bend. These showed the fretted U-bend tubes to be localized in the area bounded by Rows 70 and above, and Columns 39 to 83 which has been defined as the 'Area at Risk' of U-bend fretting for Darlington SGs. In the distribution of the frets at the U-bend support locations, they showed a strong biasing of the fretting towards the cold leg supports with the mean centered a third the way between CU4 and CU3. A general understanding of the 'Root Cause of Fretting' shows it to be associated with tube clearance, which invariably results and acts together with conditions of insufficient support preload. While the fretting by tube tends to exhibit a certain degree of randomness, the fretting remains localized to the 'Area at Risk'. This offers a unique opportunity of localized corrective measures that are both simpler in design

  11. 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.

  12. Effect of tube size on electromagnetic tube bulging

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The commercial finite code ANSYS was employed for the simulation of the electromagnetic tube bulging process. The finite element model and boundary conditions were thoroughly discussed. ANSYS/EMAG was used to model the time varying electromagnetic field in order to obtain the radial and axial magnetic pressure acting on the tube. The magnetic pressure was then used as boundary conditions to model the high velocity deformation of various length tube with ANSYS/LSDYNA. The time space distribution of magnetic pressure on various length tubes was presented. Effect of tube size on the distribution of radial magnetic pressure and axial magnetic pressure and high velocity deformation were discussed. According to the radial magnetic pressure ratio of tube end to tube center and corresponding dimensionless length ratio of tube to coil, the free electromagnetic tube bulging was studied in classification. The calculated results show good agreements with practice.

  13. Stability of spiral welded tubes in Quay Walls

    NARCIS (Netherlands)

    Gresnigt, A.M.; van Es, S.H.J.

    2013-01-01

    A European research project (RFCS) has started to provide economic and safe guidance for the design of spirally welded tubes in combined walls. The main motivation for this project called COMBITUBE is that the current Eurocode 3 regulations for tubes in quay walls lead to uneconomic designs, because

  14. A positive taper traveling-wave tube

    Science.gov (United States)

    Grechberg, R. W.; Roberts, L. A.

    1969-01-01

    Synchronism can be maintained between the RF beam current and the circuit electromagnetic waves over substantially the entire length of a traveling-wave tube by increasing the pitch of the last portion of the helical wave structure. There is no loss of linearity or beam conversion efficiency.

  15. Marketing Strategy of YouTube in the Czech Republic

    OpenAIRE

    Hurychová, Andrea

    2012-01-01

    The goals of the thesis are to present YouTube in the Czech Republic, to discuss its entire business model, analyze the main local competitors and mostly to suggest marketing strategy that will strengthen the position of YouTube as an online medium. The current trends in the internet society are introduced as well as the role of social media in order to understand how these factors are related to the position of YouTube in marketing. From general YouTube introduction the situation of this pla...

  16. Status of steam generator tubing integrity at Jaslovske Bohunice NPP

    Energy Technology Data Exchange (ETDEWEB)

    Cepcek, S. [Nuclear Regulatory Authority of the Slovak Republic, Trnava (Slovakia)

    1997-02-01

    Steam generator represents one of the most important component of nuclear power plants. Especially, loss of tubing integrity of steam generators can lead to the primary coolant leak to secondary circuit and in worse cases to the unit shut down or to the PTS events occurrence. Therefore, to ensure the steam generator tubing integrity and the current knowledge about tube degradation propagation and development is of the highest importance. In this paper the present status of steam generator tubing integrity in operated NPP in Slovak Republic is presented.

  17. Kajian Efektifitas Sistem Struktur Tube Dengan Sistem Struktur Tube In Tube Di Bawah Beban Gempa

    OpenAIRE

    Sihotang, Dian Frisca

    2010-01-01

    Berkembangnya teknologi telah melahirkan berbagai sistem struktur bangunan tahan gempa, seperti penggunaan sistem tube.Tube adalah merupakan frame penahan gaya yang menahan gaya gaya lateral dengan struktur kantilever kotak yang memiliki jarak kolom yang berdekatan yang dipasang pada sekeliling gedung, sehingga penampilan wajah depan gedung seperti lubang jendela jendela yang terbuka. Rancangan tube ini kemudian dimodifikasi lagi dengan menambah pengaku pada bagian dalam ( konsep tube in tube...

  18. New automatic minidisk infiltrometer: design and testing

    Directory of Open Access Journals (Sweden)

    Klípa Vladimír

    2015-06-01

    Full Text Available Soil hydraulic conductivity is a key parameter to predict water flow through the soil profile. We have developed an automatic minidisk infiltrometer (AMI to enable easy measurement of unsaturated hydraulic conductivity using the tension infiltrometer method in the field. AMI senses the cumulative infiltration by recording change in buoyancy force acting on a vertical solid bar fixed in the reservoir tube of the infiltrometer. Performance of the instrument was tested in the laboratory and in two contrasting catchments at three sites with different land use. Hydraulic conductivities determined using AMI were compared with earlier manually taken readings. The results of laboratory testing demonstrated high accuracy and robustness of the AMI measurement. Field testing of AMI proved the suitability of the instrument for use in the determination of sorptivity and near saturated hydraulic conductivity

  19. Development of techniques for the fabrication of non-destructive examination of tube-to-tube-sheet connections for sodium-heated steam generators

    International Nuclear Information System (INIS)

    Techniques involving the use of ferritic materials of proven reliability have been studied. Tube-to-tube-sheet connections have been manufactured by automatic butt-welding without filler metal using specially miniaturized torches. The paper discusses also techniques for localized heat treatment which can be employed both for production and for in-service repairs. Techniques have been developed for gamma radiographic inspection and ultrasonic testing suitable for welds of less than 10 mm internal diameter. The ultrasonic technique permits a complete inspection of welds on both tube sheets. The reflected signals are continuously recorded so that the data can be compared with those obtained during in-service inspection. (author)

  20. Detection of ''beading faults'' in welded tubes

    International Nuclear Information System (INIS)

    In the steel tube industry the word ''beading'' refers to a highly localised leak affecting the welded zone. During the pneumatic test its flow rate is generally very low no more than a few thousandths of a mm3/second. Detection of such a fault by this test is consequently slow, and those which are choked or at the limit of leakage may escape detection. For greater safety, the tube technician is now using non-destructive testing methods such as eddy-currents and ultrasonics

  1. Digital Radiography Qualification of Tube Welding

    Science.gov (United States)

    Carl, Chad

    2012-01-01

    The Orion Project will be directing Lockheed Martin to perform orbital arc welding on commodities metallic tubing as part of the Multi Purpose Crew Vehicle assembly and integration process in the Operations and Checkout High bay at Kennedy Space Center. The current method of nondestructive evaluation is utilizing traditional film based x-rays. Due to the high number of welds that are necessary to join the commodities tubing (approx 470), a more efficient and expeditious method of nondestructive evaluation is desired. Digital radiography will be qualified as part of a broader NNWG project scope.

  2. The Choking Game on YouTube

    OpenAIRE

    Defenderfer, Ellen K.; Austin, Jillian E.; Davies, W. Hobart

    2016-01-01

    The choking game (TCG) is an adolescent activity in which asphyxiation is used to obtain a “high,” occasionally resulting in seizures or death. A plethora of TCG information is available through YouTube, though this content has not been evaluated recently. The current study described TCG as portrayed in YouTube videos and compared views and ratings of TCG videos to unrelated videos. The TCG videos demonstrated diverse methods of asphyxiation, with a minority showing injury to the participants...

  3. Automatic Configuration in NTP

    Institute of Scientific and Technical Information of China (English)

    Jiang Zongli(蒋宗礼); Xu Binbin

    2003-01-01

    NTP is nowadays the most widely used distributed network time protocol, which aims at synchronizing the clocks of computers in a network and keeping the accuracy and validation of the time information which is transmitted in the network. Without automatic configuration mechanism, the stability and flexibility of the synchronization network built upon NTP protocol are not satisfying. P2P's resource discovery mechanism is used to look for time sources in a synchronization network, and according to the network environment and node's quality, the synchronization network is constructed dynamically.

  4. Downhole pulse tube refrigerators

    Energy Technology Data Exchange (ETDEWEB)

    Swift, G.; Gardner, D. [Los Alamos National Lab., NM (United States). Condensed Matter and Thermal Physics Group

    1997-12-01

    This report summarizes a preliminary design study to explore the plausibility of using pulse tube refrigeration to cool instruments in a hot down-hole environment. The original motivation was to maintain Dave Reagor`s high-temperature superconducting electronics at 75 K, but the study has evolved to include three target design criteria: cooling at 30 C in a 300 C environment, cooling at 75 K in a 50 C environment, cooling at both 75 K and 30 C in a 250 C environment. These specific temperatures were chosen arbitrarily, as representative of what is possible. The primary goals are low cost, reliability, and small package diameter. Pulse-tube refrigeration is a rapidly growing sub-field of cryogenic refrigeration. The pulse tube refrigerator has recently become the simplest, cheapest, most rugged and reliable low-power cryocooler. The authors expect this technology will be applicable downhole because of the ratio of hot to cold temperatures (in absolute units, such as Kelvin) of interest in deep drilling is comparable to the ratios routinely achieved with cryogenic pulse-tube refrigerators.

  5. Prawns in Bamboo Tube

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Ingredients: 400 grams Jiwei prawns, 25 grams pork shreds, 5 grams sliced garlic. Condiments: 5 grams cooking oil, minced ginger root and scallions, cooking wine, salt, pepper and MSG (optional) Method: 1. Place the Shelled prawns into a bowl and mix with all the condiments. 2. Stuff the prawns into a fresh bamboo tube,

  6. Laser Welding Of Finned Tubes Made Of Austenitic Steels

    Directory of Open Access Journals (Sweden)

    Stolecki M.

    2015-09-01

    Full Text Available This paper describes the technology of welding of finned tubes made of the X5CrNi1810 (1.4301 austenitic steel, developed at Energoinstal SA, allowing one to get high quality joints that meet the requirements of the classification societies (PN-EN 15614, and at the same time to significantly reduce the manufacturing costs. The authors described an automatic technological line equipped with a Trumph disc laser and a tube production technological process. To assess the quality of the joints, one performed metallographic examinations, hardness measurements and a technological attempt to rupture the fin. Analysis of the results proved that the laser-welded finned tubes were performed correctly and that the welded joints had shown no imperfections.

  7. Semi-automatic analysis of fire debris

    Science.gov (United States)

    Touron; Malaquin; Gardebas; Nicolai

    2000-05-01

    Automated analysis of fire residues involves a strategy which deals with the wide variety of received criminalistic samples. Because of unknown concentration of accelerant in a sample and the wide range of flammable products, full attention from the analyst is required. Primary detection with a photoionisator resolves the first problem, determining the right method to use: the less responsive classical head-space determination or absorption on active charcoal tube, a better fitted method more adapted to low concentrations can thus be chosen. The latter method is suitable for automatic thermal desorption (ATD400), to avoid any risk of cross contamination. A PONA column (50 mx0.2 mm i.d.) allows the separation of volatile hydrocarbons from C(1) to C(15) and the update of a database. A specific second column is used for heavy hydrocarbons. Heavy products (C(13) to C(40)) were extracted from residues using a very small amount of pentane, concentrated to 1 ml at 50 degrees C and then placed on an automatic carousel. Comparison of flammables with referenced chromatograms provided expected identification, possibly using mass spectrometry. This analytical strategy belongs to the IRCGN quality program, resulting in analysis of 1500 samples per year by two technicians. PMID:10802196

  8. Automatic summary evaluation based on text grammars

    OpenAIRE

    Branny, Emilia

    2007-01-01

    In this paper, I describe a method for evaluating automatically generated text summaries. The method is inspired by research in text grammars by Teun Van Dijk. It addresses a text as a complex structure, the elements of which are interconnected both on the level of form and meaning, and the well-formedness of which should be described on both of these levels. The method addresses current problems of summary evaluation methods, especially the problem of quantifying informativity, as well as th...

  9. Eddy currents signal processing for steam generator inspection in PWR nuclear power plants

    International Nuclear Information System (INIS)

    Steam generator tubes in nuclear power plants are periodically checked by means of eddy current probes. The output of a probe is composed of three types of signals: known events (rolling zone, support plates, U-bend part), noise (mainly metallurgical noise) and possible flaws. The latter are random transients, both in arrival time and in shape: they have to be detected and then estimated, before to be fed to the high level stages of a diagnostics system. The objective of the study presented is to develop a semi-automatic system, which could manage and process more than 1 M-bytes of data per tube and provide an operator with reliable diagnostics proposals within a few minutes. This can be achieved only by cooperation of several digital signal processing techniques: detection, segmentation, estimation, noise subtraction, adaptive filtering, modelization, pattern recognition. The paper describes some of these items

  10. Eustachian tube function in children after insertion of ventilation tubes.

    NARCIS (Netherlands)

    Heerbeek, N. van; Ingels, K.J.A.O.; Snik, A.F.M.; Zielhuis, G.A.

    2001-01-01

    This study was performed to assess the effect of the insertion of ventilation tubes and the subsequent aeration of the middle ear on eustachian tube (ET) function in children. Manometric ET function tests were performed repeatedly for 3 months after the placement of ventilation tubes in 83 children

  11. Restore condition of Incore thimble tubes in guide tubes

    Energy Technology Data Exchange (ETDEWEB)

    Solanas, A.; Izquierdo, J.

    2014-07-01

    Aging of Nuclear Power Plant and succession of outages lead to wear and twist of the thimbles tubes but also to the fooling of Incore guide tubes. These can create friction and a high strength must be used for thimble tubes withdrawal. (Author)

  12. Confocal microlaparoscope for imaging the fallopian tube

    Science.gov (United States)

    Wu, Tzu-Yu; Schafer, Rachel; Rouse, Andrew R.; Gmitro, Arthur F.

    2012-02-01

    Recent evidence suggests that epithelial ovarian cancer may originate in the fimbriated end of the fallopian tube1. Unlike many other cancers, poor access to the ovary and fallopian tubes has limited the ability to study the progression of this deadly disease and to diagnosis it during the early stage when it is most amenable to therapy. We have previously reported on a rigid confocal microlaparoscope system that is currently undergoing a clinical trial to image the epithelial surface of the ovary2. In order to gain in vivo access to the fallopian tubes we have developed a new confocal microlaparoscope with an articulating distal tip. The new instrument builds upon the technology developed for the existing confocal microlaparoscope. It has an ergonomic handle fabricated by a rapid prototyping printer. While maintaining compatibility with a 5 mm trocar, the articulating distal tip of the instrument consists of a 2.2 mm diameter bare fiber bundle catheter with automated dye delivery for fluorescence imaging. This small and flexible catheter design should enable the confocal microlaparoscope to image early stage ovarian cancer arising inside the fallopian tube. Early ex vivo mages of human fallopian tube and in vivo imaging results from recent open surgeries using the rigid confocal microlaparoscope system are presented. Ex vivo images from animal models using the new articulating bare fiber system are also presented. These high quality images collected by the new flexible system are similar in quality to those obtained from the epithelial surface of ovaries with the rigid clinical confocal microlaparoscope.

  13. Mechanical properties of ceramic composite tubes

    Energy Technology Data Exchange (ETDEWEB)

    Curtin, W.A.; Oleksuk, L.L.; Reifsnider, K.L. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States); Stinton, D.P. [Oak Ridge National Lab., TN (United States)

    1995-08-01

    Results of axial tension tests on SiC/SiC tubular ceramic composite components fabricated by a forced-M technique are presented. Axial elastic modulus measurements on a number of tubes show that the Young`s modulus varies along the length of the tube, with occasional very stiff or very soft regions. Tests to failure on a few tubes show the initiation of non-linear stress-strain behavior to be in the range of 3-9 ksi, followed by extensive non-linear deformation up to failure. For one tube, the failure stress obtained was 20.1 ksi, but the strains to failure at various axial locations varies from 0.19%to 0.24%. The correlation between modulus and proportional limit is considered within the ACK matrix cracking theory and within a model in which matrix cracking between fiber tows occurs, both modified to account for matrix porosity. The crack size required to cause stress concentrations large enough to cause failure at the observed strength is considered. Predictions for both matrix cracking and strength suggest that the current generation of tubes are controlled by microstructural defects.

  14. MARZ: Manual and automatic redshifting software

    Science.gov (United States)

    Hinton, S. R.; Davis, Tamara M.; Lidman, C.; Glazebrook, K.; Lewis, G. F.

    2016-04-01

    The Australian Dark Energy Survey (OzDES) is a 100-night spectroscopic survey underway on the Anglo-Australian Telescope using the fibre-fed 2-degree-field (2dF) spectrograph. We have developed a new redshifting application MARZ with greater usability, flexibility, and the capacity to analyse a wider range of object types than the RUNZ software package previously used for redshifting spectra from 2dF. MARZ is an open-source, client-based, Javascript web-application which provides an intuitive interface and powerful automatic matching capabilities on spectra generated from the AAOmega spectrograph to produce high quality spectroscopic redshift measurements. The software can be run interactively or via the command line, and is easily adaptable to other instruments and pipelines if conforming to the current FITS file standard is not possible. Behind the scenes, a modified version of the AUTOZ cross-correlation algorithm is used to match input spectra against a variety of stellar and galaxy templates, and automatic matching performance for OzDES spectra has increased from 54% (RUNZ) to 91% (MARZ). Spectra not matched correctly by the automatic algorithm can be easily redshifted manually by cycling automatic results, manual template comparison, or marking spectral features.

  15. Flaw Detection in Thin-Walled Tubes

    International Nuclear Information System (INIS)

    The author considers the special features and advantages of ultrasonic methods of detecting flaws in thin-walled tubes by means of Lamb's waves and describes the apparatus used. In addition to standard methods of inspecting and testing tubes, ultrasonics and eddy currents are now widely used in detecting concealed defects (fissures, non-metallic inclusions, foliation, blisters), deep notches, cracks and scratches on inner surfaces, determining grain size, and measuring wall thickness and corrosion depth. For the ultrasonic detection of flaws in thin-walled tubes using Lamb's waves one must work on the relatively flat parts of the dispersion curves. For example, greatest sensitivity to foliation during inspection by the reflection method is possessed by anti-symmetrical waves of the first and second modes. The author shows the effect of non-uniform thickness and ovalness of tubes on signal fluctuations in inspection by the shadow method. Metal structure is tested by the ''ratio'' method based on a comparison between signals of different frequency which are reflected by or which pass through the materials. In smooth and finned thin-walled tubes with diameters of 3 to 60 mm and wall thickness of 0.2 mm or more, made of stainless steel, high-nickel, zirconium, aluminium and other alloys, defects are detected with IDTs-3M, IDTs-5, UDT-4M, UKT-2 and other ultrasonic apparatus. Inspection is carried out by the immersion technique, the shadow method and the reflection method with working frequencies up to 10 MHz. Positive detection is achieved of defects over 0.5 mm in length and with a depth of 5% of the wall thickness. Grain size is controlled by USAD-61 structure analysers. Eddy-current apparatus is used for measuring the wall thickness of tubes made of non-magnetic materials. (author)

  16. Automatic personnel contamination monitor

    International Nuclear Information System (INIS)

    United Nuclear Industries, Inc. (UNI) has developed an automatic personnel contamination monitor (APCM), which uniquely combines the design features of both portal and hand and shoe monitors. In addition, this prototype system also has a number of new features, including: micro computer control and readout, nineteen large area gas flow detectors, real-time background compensation, self-checking for system failures, and card reader identification and control. UNI's experience in operating the Hanford N Reactor, located in Richland, Washington, has shown the necessity of automatically monitoring plant personnel for contamination after they have passed through the procedurally controlled radiation zones. This final check ensures that each radiation zone worker has been properly checked before leaving company controlled boundaries. Investigation of the commercially available portal and hand and shoe monitors indicated that they did not have the sensitivity or sophistication required for UNI's application, therefore, a development program was initiated, resulting in the subject monitor. Field testing shows good sensitivity to personnel contamination with the majority of alarms showing contaminants on clothing, face and head areas. In general, the APCM has sensitivity comparable to portal survey instrumentation. The inherit stand-in, walk-on feature of the APCM not only makes it easy to use, but makes it difficult to bypass. (author)

  17. Development and quality assessments of commercial heat production of ATF FeCrAl tubes

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Yukinori [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-09-01

    Development and quality assessment of the 2nd generation ATF FeCrAl tube production with commercial manufacturers were conducted. The manufacturing partners include Sophisticated Alloys, Inc. (SAI), Butler, PA for FeCrAl alloy casting via vacuum induction melting, Oak Ridge National Laboratory (ORNL) for extrusion process to prepare the master bars/tubes to be tube-drawn, and Rhenium Alloys, Inc. (RAI), North Ridgeville, OH, for tube-drawing process. The masters bars have also been provided to Los Alamos National Laboratory (LANL) who works with Century Tubes, Inc., (CTI), San Diego, CA, as parallel tube production effort under the current program.

  18. Laser welding of a tube

    International Nuclear Information System (INIS)

    For sleeving PWR steam generator tubes, the welding laser work is made under protection of a primary gas going out by the crossing window of the laser and under a secondary gas flowing axially through the head and the tube

  19. Quarter-wave pulse tube

    Science.gov (United States)

    Swift, G. W.; Gardner, D. L.; Backhaus, S. N.

    2011-10-01

    In high-power pulse-tube refrigerators, the pulse tube itself can be very long without too much dissipation of acoustic power on its walls. The pressure amplitude, the volume-flow-rate amplitude, and the time phase between them evolve significantly along a pulse tube that is about a quarter-wavelength long. Proper choice of length and area makes the oscillations at the ambient end of the long pulse tube optimal for driving a second, smaller pulse-tube refrigerator, thereby utilizing the acoustic power that would typically have been dissipated in the first pulse-tube refrigerator's orifice. Experiments show that little heat is carried from the ambient heat exchanger to the cold heat exchanger in such a long pulse tube, even though the oscillations are turbulent and even when the tube is compactly coiled.

  20. 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.

  1. Ultrasonic nondestructive tubing inspection system

    International Nuclear Information System (INIS)

    A system for measuring the extent of tube wall erosion in an inspection region of a heat exchanger tube of a nuclear steam generator, uses an ultrasonic means driven helically inside the eroded tube which may be filled with a fluid (e.g., water) to minimize ultrasonic wave attenuation. A control means cooperates with the ultrasonic means to produce a map of the tube wall thickness in an inspection region

  2. Development and formability analysis of TRIP seamless steel tube

    Institute of Scientific and Technical Information of China (English)

    Zhang Zicheng; Zhu Fuxian

    2014-01-01

    In this paper,the production technology of transformation induced plasticity (TRIP) steel was first introduced into the steel tube manufacture field to produce the steel tubes with high strength and plasticity. The TRIP seamless steel tubes with the microstructure of ferrite,bainite,retained austenite and a little martensite were successfully fabricated using a cold-drawn steel tube with two-stage heat treatment technique and continu-ous heat treatment process,respectively. The ring tensile test and cold bend test were carried out to study the formability of the newly developed TRIP seamless steel tube. The results showed that the TRIP seamless steel tubes have a good cold formability,and they are available to be used in the tube hydroforming process. In ad-dition,the equipment of continuous heat treatment developed in the current study can be used to produce TRIP steel tube,and it may serve as an important reference for the industrial production of TRIP steel tube.

  3. A method of automatic control procedures cardiopulmonary resuscitation

    Science.gov (United States)

    Bureev, A. Sh.; Zhdanov, D. S.; Kiseleva, E. Yu.; Kutsov, M. S.; Trifonov, A. Yu.

    2015-11-01

    The study is to present the results of works on creation of methods of automatic control procedures of cardiopulmonary resuscitation (CPR). A method of automatic control procedure of CPR by evaluating the acoustic data of the dynamics of blood flow in the bifurcation of carotid arteries and the dynamics of air flow in a trachea according to the current guidelines for CPR is presented. Evaluation of the patient is carried out by analyzing the respiratory noise and blood flow in the interspaces between the chest compressions and artificial pulmonary ventilation. The device operation algorithm of automatic control procedures of CPR and its block diagram has been developed.

  4. Sleeve puller salvages welded tubes

    Science.gov (United States)

    Weaver, J. F.

    1980-01-01

    Tool removes sleeve remnants without distorting or damaging tubes, unlike pliers and other conventional handtools. Tubes can be reused, saving time, labor, and material in many applications. Sleeve-removal fixture consists of pressure screw, swing arm, locking screws, and base. It removes sleeve remnant from tubing after welded joint has been sawed through.

  5. Enteral Tube Feeding and Pneumonia

    Science.gov (United States)

    Gray, David Sheridan; Kimmel, David

    2006-01-01

    To determine the effects of enteral tube feeding on the incidence of pneumonia, we performed a retrospective review of all clients at our institution who had gastrostomy or jejunostomy tubes placed over a 10-year period. Ninety-three subjects had a history of pneumonia before feeding tube insertion. Eighty had gastrostomy and 13, jejunostomy…

  6. Wear on Plugged Tube due to the Foreign Objects on the Secondary Side of Steam Generator

    International Nuclear Information System (INIS)

    In this paper, the changes of the tube frequency and amplitude are introduced before and after plugging. The amplitude of the bottom span for the steam generator tube is not much changed after tube plugging. Moreover, the contact force between the plugged tube and the foreign object is the same as that of intact tube and the foreign object. However, the frequencies of plugged tubes are about 9∼12% higher than those of intact tubes. That means the wear due to the foreign object would be accelerated after the tube plugging. Therefore, the tube stabilizer should be installed when the tube is plugged due to the foreign object wear. The tube wall of steam generator is a pressure boundary between the coolant of the primary system and the feedwater of the secondary system. It is very important to insure the structural integrity of the tubes because the radioactive coolant is flow into the feedwater due to the pressure difference as the result of tube failure. The degradations of steam generator tubes are corrosion, wear, fatigue and foreign object wear, etc. The foreign object wear is one of mechanical degradation due to materials flew into the secondary side of steam generator. The steam generator tubes, estimated not to insure structural integrity from the results of the nondestructive evaluation such as eddy current test and visual inspection, are excluded from the service with plugging. However, the tube wear is still being progressed after the plugging because the relative motion between the tube and structure is still existed due to the secondary side flow in the steam generator. If the tube is completely cut because of the degradation, the tube can be a stress or of failure of tubes around the plugged tube. The contact force between the structure and tube is lowered as the wear is progressed. However, the contact force between the foreign object and tube is not changed as the wear is progressed. Therefore, the structural integrity of tubes around the foreign

  7. [Automatic regulator of venous pressure and venous outflow in the perfusion system].

    Science.gov (United States)

    Smirnov, L M; Levinskiĭ, M M; Kharnas, S Sh; Cherniak, V A

    1976-01-01

    A scheme for automatic regulation of the venous pressure and venous blood outflow during extracorporeal circulation is proposed. The system consists of a photoelectric sensor placed on a tube led out of the major venous trunkline, a converter and an electromechanical eccentric clamp that compresses the venous trunkline, all of which secures stabilization of the controlled values.

  8. Neural tube defects

    Directory of Open Access Journals (Sweden)

    M.E. Marshall

    1981-09-01

    Full Text Available Neural tube defects refer to any defect in the morphogenesis of the neural tube, the most common types being spina bifida and anencephaly. Spina bifida has been recognised in skeletons found in north-eastern Morocco and estimated to have an age of almost 12 000 years. It was also known to the ancient Greek and Arabian physicians who thought that the bony defect was due to the tumour. The term spina bifida was first used by Professor Nicolai Tulp of Amsterdam in 1652. Many other terms have been used to describe this defect, but spina bifida remains the most useful general term, as it describes the separation of the vertebral elements in the midline.

  9. The Large-Scale Sugarcane Stripper with Automatic Feeding

    OpenAIRE

    Jiaxiang Lin; Wenjie Yan; Jiaping Lin

    2012-01-01

    This study mainly introduce the large-scale sugarcane stripper with automatic feeding, which including the automatic feeding module, cleaning leaves module, collecting module and control module. The machine is an important part of the segmental type sugarcane harvester, using to solve the highest labor intensity problem of cleaning leaves. Collecting the hilly areas sugarcane and cleaning their leaves, can greatly improve the labor productivity and changing the current mode of sugarcane harvest.

  10. Design of Automatic Extraction Algorithm of Knowledge Points for MOOCs

    OpenAIRE

    Haijian Chen; Dongmei Han; Yonghui Dai; Lina Zhao

    2015-01-01

    In recent years, Massive Open Online Courses (MOOCs) are very popular among college students and have a powerful impact on academic institutions. In the MOOCs environment, knowledge discovery and knowledge sharing are very important, which currently are often achieved by ontology techniques. In building ontology, automatic extraction technology is crucial. Because the general methods of text mining algorithm do not have obvious effect on online course, we designed automatic extracting course ...

  11. JAPS: an automatic parallelizing system based on JAVA

    Institute of Scientific and Technical Information of China (English)

    杜建成; 陈道蓄; 谢立

    1999-01-01

    JAPS is an automatic parallelizing system based on JAVA running on NOW. It implements the automatic process from dependence analysis to parallel execution. The current version of JAPS can exploit functional parallelism and the detection of data parallelism will be incorporated in the new version, which is underway. The framework and key techniques of JAPS are presented. Specific topics discussed are task partitioning, summary information collection, data dependence analysis, pre-scheduling and dynamic scheduling, etc.

  12. Automatic control system for measuring currents produced by ionization chambers; Automatizacao de um sistema de medidas de correntes produzidas por camaras de ionizacao e aplicacao na calibracao do {sup 18}F e {sup 153}Sm

    Energy Technology Data Exchange (ETDEWEB)

    Brancaccio, Franco

    2002-07-01

    Ionization Chambers in current mode operation are usually used in Nuclear Metrology. Activity measurements are quickly performed by Ionization Chambers, with very good precision. For this purpose measurements of very low ionization currents, carried out by high quality instrumentation, are required. Usually, electrometers perform the current integration method under command of signals from an automation system, in order to reduce the measurement uncertainties. Among the measurement systems at the Laboratorio de Metrologia Nuclear (LMN) of IPEN, there are two ionization chamber systems. In the present work, an automation system developed for current integration measurements is described. This automation system is composed by software (graphic interface and control) and an electronic module connected to a microcomputer, by means of a commercial data acquisition card. Several test measurements were performed in order to determine the intrinsic uncertainty, linearity and stability of the system. Using calibrated radioactive solutions, the IG12/A20 chamber calibration factors for {sup 18}F and {sup 153}Sm were obtained, making possible to determine activities of these radionuclides. (author)

  13. Fabrication of seamless calandria tubes

    International Nuclear Information System (INIS)

    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 fr 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

  14. Primary fallopian tube carcinoma

    Directory of Open Access Journals (Sweden)

    Mladenović-Segedi Ljiljana

    2009-01-01

    Full Text Available Introduction. Primary fallopian tube carcinoma is extremely rare, making 0.3-1.6% of all female genital tract malignancies. Although the etymology of this tumor is unknown, it is suggested to be associated with chronic tubal inflammation, infertility, tuberculous salpingitis and tubal endometriosis. High parity is considered to be protective. Cytogenetic studies show the disease to be associated with over expression of p53, HER2/neu and c-myb. There is also some evidence that BRCA1 and BRCA2 mutations have a role in umorogeneis. Clinical features. The most prevailing symptoms with fallopian tube carcinoma are abdominal pain, abnormal vaginal discharge/bleeding and the most common finding is an adnexal mass. In many patients, fallopian tube carcinoma is asymptomatic. Diagnosis. Due to its rarity, preoperative diagnosis of primary fallopian tube carcinoma is rarely made. It is usually misdiagnosed as ovarian carcinoma, tuboovarian abscess or ectopic pregnancy. Sonographic features of the tumor are non-specific and include the presence of a fluid-filled adnexal structure with a significant solid component, a sausage-shaped mass, a cystic mass with papillary projections within, a cystic mass with cog wheel appearance and an ovoid-shaped structure containing an incomplete separation and a highly vascular solid nodule. More than 80% of patients have elevated pretreatment serum CA-125 levels, which is useful in follow-up after the definite treatment. Treatment. The treatment approach is similar to that of ovarian carcinoma, and includes total abdominal hysterectomy and bilateral salpingo-oophorectomy. Staging is followed with chemotherapy.

  15. YouTube advertising and its significance in the Czech Republic

    OpenAIRE

    Borýsek, Jan

    2014-01-01

    This bachelor's thesis is dealing with current possibilities of advertising on YouTube in the Czech Republic. Based on the analysis of selected advertising campaigns on YouTube it evaluates its effectiveness and impact. By author's own research it identifies internet users' attitude towards advertising on YouTube in comparison with television advertising. The thesis also compares selected media indicators of YouTube and television.

  16. Clogging of feeding tubes.

    Science.gov (United States)

    Marcuard, S P; Perkins, A M

    1988-01-01

    This is a report of an in vitro study evaluating clotting ability of some formulas with intact protein and hydrolyzed protein sources in a series of buffers ranging from a pH of 1 thru 10. The following 10 products were tested: Ensure Plus, Ensure, Enrich, Osmolite, Pulmocare, Citrotein, Resource, Vivonex TEN, Vital, and Hepatic Acid II. Protein (10 and 20 g/liter) was added to Citrotein and Ensure Plus. All formulas were tested at full and some at half strength. Clotting occurred only in premixed intact protein formulas (Pulmocare, Ensure Plus, Osmolite, Enrich, Ensure) and in Resource. No clotting was observed for Citrotein (intact protein formula in powder form), Vital, Vivonex TEN, and Hepatic Aid II. Adding protein did not cause or increase clotting. In summary, clotting of some liquid formula diet appears to be an important factor causing possible gastric feeding tube occlusion. The following measures may help in preventing this problem: flushing before and after aspirating for gastric residuals to eliminate acid precipitation of formula in the feeding tube, advance the nasogastric feeding tube into the duodenum if possible, and avoid mixing these products with liquid medications having a pH value of 5.0 or less. PMID:3138452

  17. Traveling-Wave Tubes

    Science.gov (United States)

    Kory, Carol L.

    1998-01-01

    The traveling-wave tube (TWT) is a vacuum device invented in the early 1940's used for amplification at microwave frequencies. Amplification is attained by surrendering kinetic energy from an electron beam to a radio frequency (RF) electromagnetic wave. The demand for vacuum devices has been decreased largely by the advent of solid-state devices. However, although solid state devices have replaced vacuum devices in many areas, there are still many applications such as radar, electronic countermeasures and satellite communications, that require operating characteristics such as high power (Watts to Megawatts), high frequency (below 1 GHz to over 100 GHz) and large bandwidth that only vacuum devices can provide. Vacuum devices are also deemed irreplaceable in the music industry where musicians treasure their tube-based amplifiers claiming that the solid-state and digital counterparts could never provide the same "warmth" (3). The term traveling-wave tube includes both fast-wave and slow-wave devices. This article will concentrate on slow-wave devices as the vast majority of TWTs in operation fall into this category.

  18. Industrial mastering the use of tube fining by high-frequency welding for gasproof boilers

    International Nuclear Information System (INIS)

    Results of introduction of 20 and 12Kh1MF steel tube fining by high-frequency welding are presented. Heat treatment effect on properties of joints is studied, mechanical tests, metallographical and electron-microscopic investigations are carried out. It is shown that weld method of fins to tubes with the help of high-frequency currents is characterized by universality that permits to produce fined tubes of practically any diameter with fins of any width, control of smooth tubes before the fins welding to them being provided. Studies of properties of fined tubes has shown high quality of welded joints carried out by high-frequency current heating

  19. CRL X-RAY TUBE

    OpenAIRE

    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.

  20. Reliability of steam generator tubing

    Energy Technology Data Exchange (ETDEWEB)

    Kadokami, E. [Mitsubishi Heavy Industries Ltd., Hyogo-ku (Japan)

    1997-02-01

    The author presents results on studies made of the reliability of steam generator (SG) tubing. The basis for this work is that in Japan the issue of defects in SG tubing is addressed by the approach that any detected defect should be repaired, either by plugging the tube or sleeving it. However, this leaves open the issue that there is a detection limit in practice, and what is the effect of nondetectable cracks on the performance of tubing. These studies were commissioned to look at the safety issues involved in degraded SG tubing. The program has looked at a number of different issues. First was an assessment of the penetration and opening behavior of tube flaws due to internal pressure in the tubing. They have studied: penetration behavior of the tube flaws; primary water leakage from through-wall flaws; opening behavior of through-wall flaws. In addition they have looked at the question of the reliability of tubing with flaws during normal plant operation. Also there have been studies done on the consequences of tube rupture accidents on the integrity of neighboring tubes.

  1. Wet channel measurement of pressure tube to calandria tube spacing in CANDU reactors

    International Nuclear Information System (INIS)

    The pressure tube (PT) to calandria tube (CT) spacing in CANDU reactors is an important parameter that relates to the general condition of the fuel channels. The measurement system that was developed to measure this parameter during the wet channel inspections of Pickering Units 1 and 2 is described in this paper. A send-receive eddy current probe was designed which is primarily sensitive to variations in PT/CT spacing but is also affected by pressure tube wall thickness. A computer simulation showed that the phase angles of the response to these variables are similar for all usable frequencies, thus eliminating the possibility of multifrequency compensation. A marriage of technologies was proposed involving the ultrasonic measurement of wall thickness values which are then used to extract the spacing information from the eddy current signal. The accuracy of the system is approximately ±(30% +.1mm) which has been sufficient to determine if and where any of the pressure tubes have come in contact with their calandria tube. Field experience with the new system is discussed and areas for development are also outlined

  2. Microdischarges in DC accelerator tubes

    International Nuclear Information System (INIS)

    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)

  3. Template synthesized chitosan nano test tubes for drug delivery applications

    Science.gov (United States)

    Perry, Jillian L. Moulton

    There is tremendous current interest in developing nanoscale drug delivery vehicles. Though intensive efforts have focused on developing spherical drug delivery vehicles, cylindrically shaped vehicles such as nanotubes offer many advantages. Typically, nanotubes can carry a larger inner payload than nanoparticles of the same diameter. Also, we can prepare nanotubes in templates whose geometries can be controlled, in turn allowing precise control over the length and diameter of the tubes. In addition, template synthesized nanotubes can be differentially functionalized on the inner and outer surfaces. Furthermore, templates that are closed on one end can be used to fabricate nano test tubes (closed on one end). The geometry of these nano test tubes allows them to be easily filled with a payload, the open end sealed with a nanoparticle to protect the payload from leaking out, and then the exterior of the tube can be functionalized with a targeting moiety. In an effort to develop such a system, we explored the fabrication of chitosan nano test tubes. Defect-free, chitosan nano test tubes of uniform size were synthesized within the pores of a nanoporous alumina template membrane. While the nano test tubes remained within the template membrane, their inner cavities were filled with a model payload. The payload was then trapped inside the nano test tubes by sealing the open ends of the tubes with latex nanoparticle caps. For proof-of-principle studies, imine linkages were used to attach the caps to the nano test tubes. To create a self-disassembling system, disulfide chemistry was used to covalently cap the nano test tubes. Once removed from the template, the exterior of the nano test tubes were modified with a targeting moiety, allowing them to be targeted to pathological sites. We have also shown that the chitosan nano test tubes are biodegradable by two systems: enzymatic cleavage by lysozymes and disulfide cleavage of the crosslinker by reducing environments

  4. Ultrasonic inspection of tube to tube plate welds

    International Nuclear Information System (INIS)

    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)

  5. Automatic modulation recognition of communication signals

    CERN Document Server

    Azzouz, Elsayed Elsayed

    1996-01-01

    Automatic modulation recognition is a rapidly evolving area of signal analysis. In recent years, interest from the academic and military research institutes has focused around the research and development of modulation recognition algorithms. Any communication intelligence (COMINT) system comprises three main blocks: receiver front-end, modulation recogniser and output stage. Considerable work has been done in the area of receiver front-ends. The work at the output stage is concerned with information extraction, recording and exploitation and begins with signal demodulation, that requires accurate knowledge about the signal modulation type. There are, however, two main reasons for knowing the current modulation type of a signal; to preserve the signal information content and to decide upon the suitable counter action, such as jamming. Automatic Modulation Recognition of Communications Signals describes in depth this modulation recognition process. Drawing on several years of research, the authors provide a cr...

  6. Automatic breast density classification using neural network

    Science.gov (United States)

    Arefan, D.; Talebpour, A.; Ahmadinejhad, N.; Kamali Asl, A.

    2015-12-01

    According to studies, the risk of breast cancer directly associated with breast density. Many researches are done on automatic diagnosis of breast density using mammography. In the current study, artifacts of mammograms are removed by using image processing techniques and by using the method presented in this study, including the diagnosis of points of the pectoral muscle edges and estimating them using regression techniques, pectoral muscle is detected with high accuracy in mammography and breast tissue is fully automatically extracted. In order to classify mammography images into three categories: Fatty, Glandular, Dense, a feature based on difference of gray-levels of hard tissue and soft tissue in mammograms has been used addition to the statistical features and a neural network classifier with a hidden layer. Image database used in this research is the mini-MIAS database and the maximum accuracy of system in classifying images has been reported 97.66% with 8 hidden layers in neural network.

  7. Automatic breast density classification using neural network

    International Nuclear Information System (INIS)

    According to studies, the risk of breast cancer directly associated with breast density. Many researches are done on automatic diagnosis of breast density using mammography. In the current study, artifacts of mammograms are removed by using image processing techniques and by using the method presented in this study, including the diagnosis of points of the pectoral muscle edges and estimating them using regression techniques, pectoral muscle is detected with high accuracy in mammography and breast tissue is fully automatically extracted. In order to classify mammography images into three categories: Fatty, Glandular, Dense, a feature based on difference of gray-levels of hard tissue and soft tissue in mammograms has been used addition to the statistical features and a neural network classifier with a hidden layer. Image database used in this research is the mini-MIAS database and the maximum accuracy of system in classifying images has been reported 97.66% with 8 hidden layers in neural network

  8. A Study on the Development of Ultrasonic Scanning Device for the Inspection and Evaluation of Creep Damage of HK - 40 Reformer Tube Welded Zone

    International Nuclear Information System (INIS)

    Detection of creep damages in centrifugally cast HK-40 reformer furnace catalyst tube is a common problem for the safety and scheduled operation of chemical plants. This study was focused on the development of an automatic ultrasonic scanning device with which the creep damage of welded zone of HK-40 reformer tubes is detected and evaluated

  9. Sign language perception research for improving automatic sign language recognition

    NARCIS (Netherlands)

    Ten Holt, G.A.; Arendsen, J.; De Ridder, H.; Van Doorn, A.J.; Reinders, M.J.T.; Hendriks, E.A.

    2009-01-01

    Current automatic sign language recognition (ASLR) seldom uses perceptual knowledge about the recognition of sign language. Using such knowledge can improve ASLR because it can give an indication which elements or phases of a sign are important for its meaning. Also, the current generation of data-d

  10. Electrical conductivity channel for a shock tube

    Science.gov (United States)

    Lu, Frank K.; Liu, Hsuan-Cheng; Wilson, Donald R.

    2005-09-01

    The design of an electrical conductivity measurement channel for a shock tube is described. This measurement channel is used for the study of weakly ionized, high-enthalpy flows of gases seeded with alkali salts. The theory for determining the dimensions of the measurement channel and the electrical power supply for the channel is based on Ohm's law. Data are shown which demonstrate that the channel performs well. However, the measured electrical conductivity was one or two orders less than theoretical values. The current traces for each case show that the peak current occurred behind the contact surface, which indicates that some of the seed was entrained behind the test gas originally in the driven tube. An analysis of the effect of Joule heating on the measured conductivity was conducted. The result of increased temperature due to Joule heating in the measurement channel is believed to be minimal. Reasons for the discrepancy are given.

  11. Investigating the Relationship between Stable Personality Characteristics and Automatic Imitation.

    Directory of Open Access Journals (Sweden)

    Emily E Butler

    Full Text Available Automatic imitation is a cornerstone of nonverbal communication that fosters rapport between interaction partners. Recent research has suggested that stable dimensions of personality are antecedents to automatic imitation, but the empirical evidence linking imitation with personality traits is restricted to a few studies with modest sample sizes. Additionally, atypical imitation has been documented in autism spectrum disorders and schizophrenia, but the mechanisms underpinning these behavioural profiles remain unclear. Using a larger sample than prior studies (N=243, the current study tested whether performance on a computer-based automatic imitation task could be predicted by personality traits associated with social behaviour (extraversion and agreeableness and with disorders of social cognition (autistic-like and schizotypal traits. Further personality traits (narcissism and empathy were assessed in a subsample of participants (N=57. Multiple regression analyses showed that personality measures did not predict automatic imitation. In addition, using a similar analytical approach to prior studies, no differences in imitation performance emerged when only the highest and lowest 20 participants on each trait variable were compared. These data weaken support for the view that stable personality traits are antecedents to automatic imitation and that neural mechanisms thought to support automatic imitation, such as the mirror neuron system, are dysfunctional in autism spectrum disorders or schizophrenia. In sum, the impact that personality variables have on automatic imitation is less universal than initial reports suggest.

  12. Steam generator tube inspection in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Fukui, Shigetaka [Japan Power Engineering and Inspection Corp., Tokyo (Japan)

    1997-02-01

    Steam generator tube inspection was first carried out in 1971 at Mihama Unit-1 that is first PWR plant in Japan, when the plant was brought into the first annual inspection. At that time, inspection was made on sampling basis, and only bobbin coil probe was used. After experiencing various kinds of tube degradations, inspection method was changed from sampling to all number of tubes, and various kinds of probes were used to get higher detectability of flaw. At present, it is required that all the tubes shall be inspected in their full length at each annual inspection using standard bobbin coil probe, and some special probes for certain plants that have susceptibility of occurrence of flaw. Sleeve repaired portion is included in this inspection. As a result of analyses of eddy current testing data, all indications that have been evaluated to be 20% wall thickness or deeper shall be repaired by either plugging or sleeving, where flaw morphology is to be a wastage or wear. Other types of flaw such as IGA/SCC are not allowed to be left inservice when those indications are detected. These inspections are performed according to inspection procedures that are approved by regulatory authority. Actual inspections are witnessed by the Japan Power engineering and inspection corporation (JAPEIC)`s inspectors during data acquisition and analysis, and they issue inspection report to authority for review and approval. It is achieved high safety performance of steam generator through this method of inspections, however. some tube leakage problems were experienced in the past. To prevent recurrence of such events, government is conducting development and verification test program for new eddy current testing technology.

  13. The Caltech Tomography Database and Automatic Processing Pipeline.

    Science.gov (United States)

    Ding, H Jane; Oikonomou, Catherine M; Jensen, Grant J

    2015-11-01

    Here we describe the Caltech Tomography Database and automatic image processing pipeline, designed to process, store, display, and distribute electron tomographic data including tilt-series, sample information, data collection parameters, 3D reconstructions, correlated light microscope images, snapshots, segmentations, movies, and other associated files. Tilt-series are typically uploaded automatically during collection to a user's "Inbox" and processed automatically, but can also be entered and processed in batches via scripts or file-by-file through an internet interface. As with the video website YouTube, each tilt-series is represented on the browsing page with a link to the full record, a thumbnail image and a video icon that delivers a movie of the tomogram in a pop-out window. Annotation tools allow users to add notes and snapshots. The database is fully searchable, and sets of tilt-series can be selected and re-processed, edited, or downloaded to a personal workstation. The results of further processing and snapshots of key results can be recorded in the database, automatically linked to the appropriate tilt-series. While the database is password-protected for local browsing and searching, datasets can be made public and individual files can be shared with collaborators over the Internet. Together these tools facilitate high-throughput tomography work by both individuals and groups. PMID:26087141

  14. Automatic Kurdish Dialects Identification

    Directory of Open Access Journals (Sweden)

    Hossein Hassani

    2016-02-01

    Full Text Available Automatic dialect identification is a necessary Lan guage Technology for processing multi- dialect languages in which the dialects are linguis tically far from each other. Particularly, this becomes crucial where the dialects are mutually uni ntelligible. Therefore, to perform computational activities on these languages, the sy stem needs to identify the dialect that is the subject of the process. Kurdish language encompasse s various dialects. It is written using several different scripts. The language lacks of a standard orthography. This situation makes the Kurdish dialectal identification more interesti ng and required, both form the research and from the application perspectives. In this research , we have applied a classification method, based on supervised machine learning, to identify t he dialects of the Kurdish texts. The research has focused on two widely spoken and most dominant Kurdish dialects, namely, Kurmanji and Sorani. The approach could be applied to the other Kurdish dialects as well. The method is also applicable to the languages which are similar to Ku rdish in their dialectal diversity and differences.

  15. Structural and leakage integrity assessment of WWER steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Splichal, K.; Otruba, J. [Nuclear Research Inst., Rez (Switzerland)

    1997-12-31

    The integrity of heat exchange tubes may influence the life-time of WWER steam generators and appears to be an important criterion for the evaluation of their safety and operational reliability. The basic requirement is to assure a very low probability of radioactive water leakage, preventing unstable crack growth and sudden tube rupture. These requirements led to development of permissible limits for primary to secondary leak evolution and heat exchange tubes plugging based on eddy current test inspection. The stress corrosion cracking and pitting are the main corrosion damage of WWER heat exchange tubes and are initiated from the outer surface. They are influenced by water chemistry, temperature and tube wall stress level. They take place under crevice corrosion condition and are indicated especially (1) under the tube support plates, where up to 90-95 % of defects detected by the ECT method occur, and (2) on free spans under tube deposit layers. Both the initiation and crack growth cause thinning of the tube wall and lead to part thickness cracks and through-wall cracks, oriented above all in the axial direction. 10 refs.

  16. Improved distribution using a fully automatic, extended apparatus

    International Nuclear Information System (INIS)

    For the separation of mixed rare earth (RE) nitrates by Craig-distribution between nitric acid and tri-n-butylphosphate an improved apparatus was used: 200 elements (tubes) and automatic operation instead of 160 elements and operation by hand. A comparison of the separation was made and the efficiency characterized by the practical separation coefficients βeff and the effective distribution number n. The new apparatus yielded a better separation of the same quantity of RE-nitrates or the same separation of a bigger quantity. The conditions seem especially apted for the separation of the heavier yttrium earths. (Authors)

  17. "Fine grain Nb tube for SRF cavities"

    Energy Technology Data Exchange (ETDEWEB)

    Robert E. Barber

    2012-07-08

    Superconducting radio frequency (SRF) cavities used in charged particle linear accelerators, are currently fabricated by deep drawing niobium sheets and welding the drawn dishes together. The Nb sheet has a non-uniform microstructure, which leads to unpredictable cavity shape and surface roughness, and inconsistent "spring-back" during forming. In addition, weld zones cause hot spots during cavity operation. These factors limit linear accelerator performance and increase cavity manufacturing cost. Equal channel angular extrusion (ECAE) can be used to refine and homogenize the microstructure of Nb tube for subsequent hydroforming into SRF cavities. Careful selection of deformation and heat treatment conditions during the processing steps can give a uniform and consistent microstructure in the tube, leading to improved deformability and lower manufacturing costs. Favorable microstructures were achieved in short test samples of RRR Nb tube, which may be particularly suitable for hydroforming into SRF cavity strings. The approach demonstrated could be applicable to microstructure engineering of other tube materials including tantalum, titanium, and zirconium.

  18. 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.

  19. Tube welding of heat exchange surfaces

    International Nuclear Information System (INIS)

    Many years experience of exploitation of a great number of butts of similar steels, made by partial fusion and with heating by high-frequency current is analysed. Their high reliability and capability of operation are observed. Taking into account the requirements of ducers of power-generating equipment, it is concluded, that subsequent development of tube butt welding by pressure must follow the way: increase of welded tube nomenclature (by diameter and thickness of the wall); improvement of methods of removing internal fin or the introduction of finless welding methods; wide use of instruments of the process parameters control and application of nondestructive control methods. It is shown, that the increase of reliability of the welded joints of tubes of similar steels (austenitic and perlitic) may be achieved by the change of the joint construction, using special spaciers and tubes of perlitic steel, containing carbide-forming elements, which exclude the softening of perlitic steel near the butt in the process of the steel operation

  20. Instrumented tube burns: theoretical and experimental observations

    Energy Technology Data Exchange (ETDEWEB)

    Yarrington, Cole Davis [Los Alamos National Laboratory; Obrey, Stephen J [Los Alamos National Laboratory; Foley, Timothy J [Los Alamos National Laboratory; Son, Steven F [Los Alamos National Laboratory

    2009-01-01

    The advent of widely available nanoscale energetic composites has resulted in a flurry of novel applications. One of these applications is the use of nanomaterials in energetic compositions. In compositions that exhibit high sensitivity to stimulus, these materials are often termed metastable intermolecular composites (MIC). More generally, these compositions are simply called nanoenergetics. Researchers have used many different experimental techniques to analyze the various properties of nanoenergetic systems. Among these various techniques, the confined tube burn is a simple experiment that is capable of obtaining much data related to the combustion of these materials. The purpose of this report is to review the current state of the confined tube burn experiment, including the drawbacks of the technique and possible remedies. As this report is intended to focus on the specific experimental technique, data from many different energetic materials, and experimental configurations will be presented. The qualitative and quantitative data that can be gathered using confined tube burn experiments include burning rates, total impulse, pressure rise rate, and burning rate differences between different detector types. All of these measurements lend insight into the combustion properties and mechanisms of specific nanoenergetics. Finally, certain data indicates a more complicated flow scenario which may need to be considered when developing burn tube models.

  1. Electronic amplifiers for automatic compensators

    CERN Document Server

    Polonnikov, D Ye

    1965-01-01

    Electronic Amplifiers for Automatic Compensators presents the design and operation of electronic amplifiers for use in automatic control and measuring systems. This book is composed of eight chapters that consider the problems of constructing input and output circuits of amplifiers, suppression of interference and ensuring high sensitivity.This work begins with a survey of the operating principles of electronic amplifiers in automatic compensator systems. The succeeding chapters deal with circuit selection and the calculation and determination of the principal characteristics of amplifiers, as

  2. ABSTRACTS WELDEL PIPE AND TUBE

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    ABSTRACTS WELDEL PIPE AND TUBE Vol.24 No.3 May.2001 Huang Jingan(1) Strengthen, Intercourse, Coordination and Promote the Development Together Liang Aiyu(11) The Production and the Development of the Water supply pipe for City Construction From the aspects of the quality, appearance, environment protection, economic analysis etc., This article evaluates the galvanized pipe, plastic steel complex pipe, plastic aluminum pipe, stainless pipe for city water supply. In accordance with the requirements of the city construction programming and development, it is considered that the plastic aluminum pipe and plastic steel pipe instead of galvanization pipe is the trend of the development. The author also gives some constructive proposals for reference. Subject Terms:galvanized pipe complex pipe stainless pipe city water supply evaluation Zhao Rongbin,Li Guangjun(14) The TIG welding of Protected Tantalum-pipe for sheathed thermocouples used in corrosive environment The protected Tantalum-pipe welding of sheathed therocouples was investigated by TIG. The welding process and its key parameters were introduced. Welding quality influenced by processing was discussed. Subject Terms:welding protected Tantalum-pipe corrosion He Defu et al(18) Design and Research for An Automatic MIG Welding Machine of Catalyst Converter of Automobile Two different schemes for automatic MIG welding of catalyst converter of automobile have been compared and analysed. A design of automatic MIG welding machine used for catalyst converter of automobile has been suggested in this paper. Subject Terms:environmental protection automobile tri-catalyst converter MIG welding automatic welding PLC Fang Chucai(24) Cold Crack Analysis of Low Alloy High Strength Steel Weld Seam Heat Affected Area During the welding of low alloy high strength (X65 and above), the fine crack occurs in the weld (especially inner weld) and the low plastic hard brickle structure occurs in the Heat Affected Area (HAZ) sometime. This

  3. Alternating sample changer and an automatic sample changer for liquid scintillation counting of alpha-emitting materials

    International Nuclear Information System (INIS)

    Two sample changers are described that were designed for liquid scintillation counting of alpha-emitting samples prepared using solvent-extraction chemistry. One operates manually but changes samples without exposing the photomultiplier tube to light, allowing the high voltage to remain on for improved stability. The other is capable of automatically counting up to 39 samples. An electronic control for the automatic sample changer is also described

  4. Device for the selective positioning of a component on a tube plate

    International Nuclear Information System (INIS)

    The invention relates to a device for the selective positioning of a component on a tube plate. It particularly applies to the positioning of a guide tube head successively opposite all the tubes of the tube bundle of a nuclear reactor steam generator. The large number of tubes in the tube bundle of the steam generator in a pressure water nuclear power station must be checked periodically for any likely corrosion. This check is effected with a Foucault current probe which is inserted in each tube in turn and is connected to a probe signal processing unit. The probe is placed in a flexible guide tube brought in turn in front of each tube of the bundle to be checked. The invention concerns a device to move the opening of a tube guide for a Foucault current detector over the entire surface of the tube plate, thereby providing access to all the tubes whilst limiting the interventions to a single positioning and a single withdrawal of the apparatus for testing all the bundle. Between the two interventions at the beginning and end of the operation, all displacements are remote controlled from outside the dangerous radioacive area

  5. Sealed ion accelerator tubes (survey)

    International Nuclear Information System (INIS)

    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

  6. Steam generator tube integrity program

    Energy Technology Data Exchange (ETDEWEB)

    Dierks, D.R.; Shack, W.J. [Argonne National Laboratory, IL (United States); Muscara, J.

    1996-03-01

    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.

  7. Remote field eddy current testing

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, Y. M.; Jung, H. K.; Huh, H.; Lee, Y. S.; Shim, C. M

    2001-03-01

    The state-of-art technology of the remote field eddy current, which is actively developed as an electromagnetic non-destructive testing tool for ferromagnetic tubes, is described. The historical background and recent R and D activities of remote-field eddy current technology are explained including the theoretical development of remote field eddy current, such as analytical and numerical approach, and the results of finite element analysis. The influencing factors for actual applications, such as the effect of frequency, magnetic permeability, receiving sensitivity, and difficulties of detection and classification of defects are also described. Finally, two examples of actual application, 1) the gap measurement between pressure tubes and calandria tube in CANDU reactor and, 2) the detection of defects in the ferromagnetic heat exchanger tubes, are described. The future research efforts are also included.

  8. A Full Automatic Device for Sampling Small Solution Volumes in Photometric Titration Procedure Based on Multicommuted Flow System

    OpenAIRE

    Borges, Sivanildo S.; Boaventura F. Reis; Gláucia P. Vieira

    2007-01-01

    In this work, an automatic device to deliver titrant solution into a titration chamber with the ability to determine the dispensed volume of solution, with good precision independent of both elapsed time and flow rate, is proposed. A glass tube maintained at the vertical position was employed as a container for the titrant solution. Electronic devices were coupled to the glass tube in order to control its filling with titrant solution, as well as the stepwise solution delivering into the titr...

  9. Effects of coil length on tube compression in electromagnetic forming

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The effects of the length of solenoid coil on tube compression in electromagnetic forming were investigated either by theory analysis or through sequential coupling numerical simulation. The details of the electromagnetic and the mechanical models in the simulation were described. The results show that the amplitude of coil current waveform and the current frequency decrease with the increase of the coil length. And the peak value of magnetic pressure is inversely proportional to the coil length. The distribution of the magnetic force acting on the tube is inhomogeneous while the tube is longer than the coil. The shortened coil length causes the increases of the maximum deformation and energy efficiency. The numerically calculated result and the experimental one of the final tube profile are in good agreement.

  10. Mechanized welding of austenitic precision stainless steel tubes

    International Nuclear Information System (INIS)

    Austenitic stainless steel tubes of material no. 1,4541 and 1,4550 are used for the tube systems to transport active and inactive gases in reactor experiments. A fully mechanical method was developed for the joining of these tubes by welding which makes use of an electrode holder with surrounding W electrode. This method, whose application is described here, enables the joining of the tubes in all welding positions. A pulsating direct current is used as welding current. Breaking tests on the welded samples gave values corresponding to the strength of the materials mentioned. The welded seams are subjected to the helium leak test and to the X-ray test. (GSCH/LH)

  11. Statistics applied to the testing of cladding tubes

    International Nuclear Information System (INIS)

    Cladding tubes, either steel or zircaloy, are generally given a 100 % inspection through ultrasonic non-destructive testing. This inspection may be completed beneficially with an eddy current test, as this is not sensitive to the same defects as those typically traced by ultrasonic testing. Unfortunately, the two methods (as with other non-destructive tests) exhibit poor precision; this means that a flaw, whose size is close to that denoted as rejection limit, may be accepted or rejected. Currently, rejection, i.e. the measurement above which a tube is rejected, is generally determined through measuring a calibration tube at regular time intervals, and the signal of a given tube is compared to that of the most recently completed calibration. This measurement is thus subject to variations which can be attributed to an actual shift of adjustments as well as to poor precision. For this reason, monitoring instrument adjustments using the so-called control chart method are proposed

  12. Evaluation of steam generator WWER 440 tube integrity criteria

    Energy Technology Data Exchange (ETDEWEB)

    Splichal, K.; Otruba, J.; Burda, J. [Nuclear Research Institute Rez plc. (Czechoslovakia)

    1997-02-01

    The main corrosion damage in WWER steam generators under operating conditions has been observed on the outer surface of these tubes. An essential operational requirement is to assure a low probability of radioactive primary water leakage, unstable defect development and rupture of tubes. In the case of WWER 440 steam generators the above requirements led to the development of permissible limits for data evaluation of the primary-to-secondary leak measurements and determination of acceptable values for plugging of heat exchange tubes based on eddy current test (ECT) inspections.

  13. Automatic Detection of Electric Power Troubles (ADEPT)

    Science.gov (United States)

    Wang, Caroline; Zeanah, Hugh; Anderson, Audie; Patrick, Clint; Brady, Mike; Ford, Donnie

    1988-01-01

    Automatic Detection of Electric Power Troubles (A DEPT) is an expert system that integrates knowledge from three different suppliers to offer an advanced fault-detection system. It is designed for two modes of operation: real time fault isolation and simulated modeling. Real time fault isolation of components is accomplished on a power system breadboard through the Fault Isolation Expert System (FIES II) interface with a rule system developed in-house. Faults are quickly detected and displayed and the rules and chain of reasoning optionally provided on a laser printer. This system consists of a simulated space station power module using direct-current power supplies for solar arrays on three power buses. For tests of the system's ablilty to locate faults inserted via switches, loads are configured by an INTEL microcomputer and the Symbolics artificial intelligence development system. As these loads are resistive in nature, Ohm's Law is used as the basis for rules by which faults are located. The three-bus system can correct faults automatically where there is a surplus of power available on any of the three buses. Techniques developed and used can be applied readily to other control systems requiring rapid intelligent decisions. Simulated modeling, used for theoretical studies, is implemented using a modified version of Kennedy Space Center's KATE (Knowledge-Based Automatic Test Equipment), FIES II windowing, and an ADEPT knowledge base.

  14. Development of an automatic reactor inspection system

    International Nuclear Information System (INIS)

    Using recent technologies on a mobile robot computer science, we developed an automatic inspection system for weld lines of the reactor vessel. The ultrasonic inspection of the reactor pressure vessel is currently performed by commercialized robot manipulators. Since, however, the conventional fixed type robot manipulator is very huge, heavy and expensive, it needs long inspection time and is hard to handle and maintain. In order to resolve these problems, we developed a new automatic inspection system using a small mobile robot crawling on the vertical wall of the reactor vessel. According to our conceptual design, we developed the reactor inspection system including an underwater inspection robot, a laser position control subsystem, an ultrasonic data acquisition/analysis subsystem and a main control subsystem. We successfully carried out underwater experiments on the reactor vessel mockup, and real reactor ready for Ulchine nuclear power plant unit 6 at Dusan Heavy Industry in Korea. After this project, we have a plan to commercialize our inspection system. Using this system, we can expect much reduction of the inspection time, performance enhancement, automatic management of inspection history, etc. In the economic point of view, we can also expect import substitution more than 4 million dollars. The established essential technologies for intelligent control and automation are expected to be synthetically applied to the automation of similar systems in nuclear power plants

  15. Dermatology on YouTube

    OpenAIRE

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

    2014-01-01

    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 inclu...

  16. 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.

  17. 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. PMID:26755987

  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. Automatic programming of simulation models

    Science.gov (United States)

    Schroer, Bernard J.; Tseng, Fan T.; Zhang, Shou X.; Dwan, Wen S.

    1988-01-01

    The objective of automatic programming is to improve the overall environment for describing the program. This improved environment is realized by a reduction in the amount of detail that the programmer needs to know and is exposed to. Furthermore, this improved environment is achieved by a specification language that is more natural to the user's problem domain and to the user's way of thinking and looking at the problem. The goal of this research is to apply the concepts of automatic programming (AP) to modeling discrete event simulation system. Specific emphasis is on the design and development of simulation tools to assist the modeler define or construct a model of the system and to then automatically write the corresponding simulation code in the target simulation language, GPSS/PC. A related goal is to evaluate the feasibility of various languages for constructing automatic programming simulation tools.

  20. Clothes Dryer Automatic Termination Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    TeGrotenhuis, Ward E.

    2014-10-01

    Volume 2: Improved Sensor and Control Designs Many residential clothes dryers on the market today provide automatic cycles that are intended to stop when the clothes are dry, as determined by the final remaining moisture content (RMC). However, testing of automatic termination cycles has shown that many dryers are susceptible to over-drying of loads, leading to excess energy consumption. In particular, tests performed using the DOE Test Procedure in Appendix D2 of 10 CFR 430 subpart B have shown that as much as 62% of the energy used in a cycle may be from over-drying. Volume 1 of this report shows an average of 20% excess energy from over-drying when running automatic cycles with various load compositions and dryer settings. Consequently, improving automatic termination sensors and algorithms has the potential for substantial energy savings in the U.S.

  1. Investigation of electron paramagnetic resonance in carbon tubes

    Science.gov (United States)

    Byszewski, P.; Nabialek, A.

    1996-04-01

    Electron paramagnetic resonance (EPR) on carbon nanotubes was measured in a wide range of temperatures, the resonance disappeared after oxidizing the tubes. The results are discussed in terms of graphite properties and a model introducing a deformation potential to describe tubular structure. It leads to persistent ring currents in the magnetic field due to the carriers circular motion around a tube. A spin angular-momentum interaction is discussed in an attempt to explain the lack of EPR in purified carbon nanotubes.

  2. Automatic Number Plate Recognition System

    OpenAIRE

    Rajshree Dhruw; Dharmendra Roy

    2014-01-01

    Automatic Number Plate Recognition (ANPR) is a mass surveillance system that captures the image of vehicles and recognizes their license number. The objective is to design an efficient automatic authorized vehicle identification system by using the Indian vehicle number plate. In this paper we discus different methodology for number plate localization, character segmentation & recognition of the number plate. The system is mainly applicable for non standard Indian number plates by recognizing...

  3. Automatización y optimización del diseño de intercambiadores de calor de tubo y coraza mediante el método de Taborek//Automatization and optimization of shell and tube heat exchangers design using the method of Taborek

    Directory of Open Access Journals (Sweden)

    Maida Bárbara Reyes‐Rodríguez

    2014-01-01

    Full Text Available Los intercambiadores de calor del tipo de coraza y tubo constituyen la parte más importante de los equipos de transferencia de calor sin combustión en las plantas de procesos químicos. Existen en la literatura numerosos métodos para el diseño de Intercambiadores de calor de tubo y coraza. Entre los más conocidos se encuentran el Método de Kern, el Método de Bell Delaware, el Método de Tinker, elMétodo de Wills and Johnston y el Método de Taborek. El presente trabajo tiene como objetivo describir y automatizar el método de Taborek. Se realiza además la optimización del Costo del Intercambiador de Calor mediante el método de Recocido Simulado y el método de los algoritmos genéticos. Se puede concluir que la optimización por ambos métodos arroja resultados similares, disminuyendoapreciablemente el costo del intercambiador optimizado.Palabras claves: optimización, intercambiadores de calor, método de Taborek, algoritmos genéticos.______________________________________________________________________________AbstractShell and tube heat exchangers are the most important equipment for heat transfer without combustion in plants of chemical processes.There are many methods for designing shell and tube heat exchangers in literature. Among the most known are the Kern´s Method, the Method of Bell Delaware, the Method ofTinker, the Method of Wills and Johnston and the Method of Taborek. The objective of this paper is to describe and automate the Taborek´s method. It is also realized and optimization of the heat exchanger cost using the genetic algorithm and Simulated Annealing. It can be concluded that the optimization usingboth methods conduces to similar results, diminishing considerably the optimized exchanger cost.Key words: optimization, Heat Exchangers, Taborek, Genetic Algorithms.

  4. Best evidence: nasogastric tube placement verification.

    Science.gov (United States)

    Longo, M Anne

    2011-08-01

    Further research on cost-effective techniques to verify enteral tube placement is warranted using a variety of pediatric populations with differing conditions that may impact gastric pH. It is imperative that clinical facilities review current policies and procedures to ensure that evidence-based findings are guiding nursing practice. Many nurses continue to rely on auscultation to verify NGT placement. Education and competency validation can assist with current practices for NGT placement being consistently incorporated by all personnel in the health care setting. Continuing to search for evidence related to nursing care will guide the direct care RN in providing best practice.

  5. Nasogastric tube syndrome induced by an indwelling long intestinal tube.

    Science.gov (United States)

    Sano, Naoki; Yamamoto, Masayoshi; Nagai, Kentaro; Yamada, Keiichi; Ohkohchi, Nobuhiro

    2016-04-21

    The nasogastric tube (NGT) has become a frequently used device to alleviate gastrointestinal symptoms. Nasogastric tube syndrome (NTS) is an uncommon but potentially life-threatening complication of an indwelling NGT. NTS is characterized by acute upper airway obstruction due to bilateral vocal cord paralysis. We report a case of a 76-year-old man with NTS, induced by an indwelling long intestinal tube. He was admitted to our hospital for treatment of sigmoid colon cancer. He underwent sigmoidectomy to release a bowel obstruction, and had a long intestinal tube inserted to decompress the intestinal tract. He presented acute dyspnea following prolonged intestinal intubation, and bronchoscopy showed bilateral vocal cord paralysis. The NGT was removed immediately, and tracheotomy was performed. The patient was finally discharged in a fully recovered state. NTS be considered in patients complaining of acute upper airway obstruction, not only with a NGT inserted but also with a long intestinal tube. PMID:27099450

  6. Nasogastric tube syndrome induced by an indwelling long intestinal tube.

    Science.gov (United States)

    Sano, Naoki; Yamamoto, Masayoshi; Nagai, Kentaro; Yamada, Keiichi; Ohkohchi, Nobuhiro

    2016-04-21

    The nasogastric tube (NGT) has become a frequently used device to alleviate gastrointestinal symptoms. Nasogastric tube syndrome (NTS) is an uncommon but potentially life-threatening complication of an indwelling NGT. NTS is characterized by acute upper airway obstruction due to bilateral vocal cord paralysis. We report a case of a 76-year-old man with NTS, induced by an indwelling long intestinal tube. He was admitted to our hospital for treatment of sigmoid colon cancer. He underwent sigmoidectomy to release a bowel obstruction, and had a long intestinal tube inserted to decompress the intestinal tract. He presented acute dyspnea following prolonged intestinal intubation, and bronchoscopy showed bilateral vocal cord paralysis. The NGT was removed immediately, and tracheotomy was performed. The patient was finally discharged in a fully recovered state. NTS be considered in patients complaining of acute upper airway obstruction, not only with a NGT inserted but also with a long intestinal tube.

  7. A taxonomy of automatic differentiation tools

    Energy Technology Data Exchange (ETDEWEB)

    Juedes, D.W. (Iowa State Univ. of Science and Technology, Ames, IA (United States). Dept. of Computer Science)

    1991-01-01

    Many of the current automatic differentiation (AD) tools have similar characteristics. Unfortunately, the similarities between these various AD tools often cannot be easily ascertained by reading the corresponding documentation. To clarify this situation, a taxonomy of AD tools is presented. The taxonomy places AD tools into the Elemental, Extensional, Integral, Operational, and Symbolic classes. This taxonomy is used to classify twenty-nine AD tools. Each tool is examined individually with respect to the mode of differentiation used and the degree of derivatives computed. A list detailing the availability of the surveyed AD tools is provided in the Appendix. 54 refs., 3 figs., 1 tab.

  8. Line matching for automatic change detection algorithm

    Science.gov (United States)

    Dhollande, Jérôme; Monnin, David; Gond, Laetitia; Cudel, Christophe; Kohler, Sophie; Dieterlen, Alain

    2012-06-01

    During foreign operations, Improvised Explosive Devices (IEDs) are one of major threats that soldiers may unfortunately encounter along itineraries. Based on a vehicle-mounted camera, we propose an original approach by image comparison to detect signicant changes on these roads. The classic 2D-image registration techniques do not take into account parallax phenomena. The consequence is that the misregistration errors could be detected as changes. According to stereovision principles, our automatic method compares intensity proles along corresponding epipolar lines by extrema matching. An adaptive space warping compensates scale dierence in 3D-scene. When the signals are matched, the signal dierence highlights changes which are marked in current video.

  9. Forming tool improves quality of tubing flares

    Science.gov (United States)

    1966-01-01

    Punch and die set improves the quality of tubing flares for use with standard flared-tube fittings in high-pressure systems. It forges a dimensionally accurate flare in the tubing and forces more tubing material into the high-stress areas to improve the strength and tightness of the tubing connection.

  10. Finite Element Analysis of Collapse of Metallic Tubes

    Directory of Open Access Journals (Sweden)

    P.K. Gupta

    2008-01-01

    Full Text Available Quasi-static axial and lateral compression tests were conducted on aluminium tubes of circular,rectangular, and square cross sections on a universal testing machine (Instron model 1197.During the compression process, different tubes were collapsed in different modes of collapse.These compression processes were also modelled using FORGE2 finite element code. The codehas the capabilities of automatic mesh generation, modelling of die, creation of material data file,carrying out the finite element computations, and post-processing of results. The deformingtube material was modelled as rigid-visco-plastic. Development of different modes of collapsewas investigated experimentally and computationally. The experimental load-compression curvesand deformed shapes are compared with the computed results and found in good agreement.It is found that the proposed finite element models of the different compression processes arecapable of predicting the modes of collapse.

  11. A computer algorithm for automatic beam steering

    Energy Technology Data Exchange (ETDEWEB)

    Drennan, E.

    1992-06-01

    Beam steering is done by modifying the current in a trim or bending magnet. If the current change is the right amount the beam can be made to bend in such a manner that it will hit a swic or BPM downstream from the magnet at a predetermined set point. Although both bending magnets and trim magnets can be used to modify beam angle, beam steering is usually done with trim magnets. This is so because, during beam steering the beam angle is usually modified only by a small amount which can be easily achieved with a trim magnet. Thus in this note, all steering magnets will be assumed to be trim magnets. There are two ways of monitoring beam position. One way is done using a BPM and the other is done using a swic. For simplicity, beam position monitoring in this paper will be referred to being done with a swic. Beam steering can be done manually by changing the current through a trim magnet and monitoring the position of the beam downstream from the magnet with a swic. Alternatively the beam can be positioned automatically using a computer which periodically updates the current through a specific number of trim magnets. The purpose of this note is to describe the steps involved in coming up with such a computer program. There are two main aspects to automatic beam steering. First a relationship between the beam position and the bending magnet is needed. Secondly a beamline setup of swics and trim magnets has to be chosen that will position the beam according to the desired specifications. A simple example will be looked at that will show that once a mathematical relationship between the needed change of the beam position on a swic and the change in trim currents is established, a computer could be programmed to calculate and update the trim currents.

  12. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... Vision Research & Ophthalmology (DIVRO) Student Training Programs NEI Home About NEI Health Information News and Events Grants ... Research at NEI Education Programs Training and Jobs Home > NEI YouTube Videos > NEI YouTube Videos: Amblyopia NEI ...

  13. Flaming on YouTube

    NARCIS (Netherlands)

    Moor, Peter J.; Heuvelman, Ard; Verleur, Ria

    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,

  14. Falling film evaporation on a tube bundle with plain and enhanced tubes

    International Nuclear Information System (INIS)

    The complexities of two-phase flow and evaporation on a tube bundle present important problems in the design of heat exchangers and the understanding of the physical phenomena taking place. The development of structured surfaces to enhance boiling heat transfer and thus reduce the size of evaporators adds another level of complexity to the modeling of such heat exchangers. Horizontal falling film evaporators have the potential to be widely used in large refrigeration systems and heat pumps, in the petrochemical industry and for sea water desalination units, but there is a need to improve the understanding of falling film evaporation mechanisms to provide accurate thermal design methods. The characterization of the effect of enhanced surfaces on the boiling phenomena occurring in falling film evaporators is thus expected to increase and optimize the performance of a tube bundle. In this work, the existing LTCM falling film facility was modified and instrumented to perform falling film evaporation measurements on single tube row and a small tube bundle. Four types of tubes were tested including: a plain tube, an enhanced condensing tube (Gewa-C+LW) and two enhanced boiling tubes (Turbo-EDE2 and Gewa-B4) to extend the existing database. The current investigation includes results for two refrigerants, R134a and R236fa, at a saturation temperature of Tsat = 5 °C, liquid film Reynolds numbers ranging from 0 to 3000, at heat fluxes between 20 and 60 kW/m² in pool boiling and falling film configurations. Measurements of the local heat transfer coefficient were obtained and utilized to improve the current prediction methods. Finally, the understanding of the physical phenomena governing the falling film evaporation of liquid refrigerants has been improved. Furthermore, a method for predicting the onset of dry patch formation has been developed and a local heat transfer prediction method for falling film evaporation based on a large experimental database has been proposed

  15. Independent tube verification and dynamic tracking in et inspection of nuclear steam generator

    International Nuclear Information System (INIS)

    The full text follows. In the examination of pressure boundary tubes in steam generators of commercial pressurized water nuclear power plants (PWR's), it is critical to know exactly which particular tube is being accessed. There are no definitive landmarks or markings on the individual tubes. Today this is done manually, it is tedious, and interrupts the normal inspection work, and is difficult due to the presence of water on the tube surface, plug ends instead of tube openings in the field of view, and varying lighting quality. In order to eliminate the human error and increase the efficiency of operation, there is a need to identify tube position during the inspection process, independent of robot encoder position and motion. A process based on a Cognex MVS-8200 system and its application function package has been developed to independently identify tube locations. ABB Combustion Engineering Nuclear Power's Outage Services group, USPPL in collaboration with ABB Power Plant Laboratories' Advanced Computers and Controls department has developed a new vision-based Independent Tube Verification system (GENESIS-ITVS-TM ). The system employ's a model-based tube-shape detection algorithm and dynamic tracking methodology to detect the true tool position and its offsets from identified tube location. GENESIS-ITVS-TM is an automatic Independent Tube Verification System (ITVS). Independent tube verification is a tube validation technique using computer vision, and not using any robot position parameters. This process independently counts the tubes in the horizontal and vertical axes of the plane of the steam generator tube sheet as the work tool is moved. Thus it knows the true position in the steam generator, given a known starting point. This is analogous to the operator's method of counting tubes for verification, but it is automated. GENESIS-ITVS-TM works independent of the robot position, velocity, or acceleration. The tube position information is solely obtained from

  16. Plugging criteria for WWER SG tubes

    Energy Technology Data Exchange (ETDEWEB)

    Papp, L.; Wilam, M. [Vitkovice NPP Services (Switzerland); Herman, M. [Vuje, Trnava (Slovakia)

    1997-12-31

    At operated Czech and Slovak nuclear power plants the 80 % criteria for crack or other bulk defect depth is used for steam generator heat exchanging tubes plugging. This criteria was accepted as the recommendation of designer of WWER steam generators. Verification of this criteria was the objective of experimental program performed by Vitkovice, J.S.C., UJV Rez, J.S.C. and Vuje Trnava, J.S.C .. Within this program the following factors were studied: (1) Influence of secondary water chemistry on defects initiation and propagation, (2) Statistical evaluation of corrosion defects progression at operated SG, and (3) Determination of critical pressure for tube rupture as a function of eddy current indications. In this presentation items (2) and (3) are considered.

  17. Plugging criteria for WWER SG tubes

    International Nuclear Information System (INIS)

    At operated Czech and Slovak nuclear power plants the 80 % criteria for crack or other bulk defect depth is used for steam generator heat exchanging tubes plugging. This criteria was accepted as the recommendation of designer of WWER steam generators. Verification of this criteria was the objective of experimental program performed by Vitkovice, J.S.C., UJV Rez, J.S.C. and Vuje Trnava, J.S.C .. Within this program the following factors were studied: (1) Influence of secondary water chemistry on defects initiation and propagation, (2) Statistical evaluation of corrosion defects progression at operated SG, and (3) Determination of critical pressure for tube rupture as a function of eddy current indications. In this presentation items (2) and (3) are considered

  18. HF electronic tubes. Technologies, grid tubes and klystrons

    International Nuclear Information System (INIS)

    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.)

  19. Analysis of cracking of co-extruded recovery boiler floor tubes

    Energy Technology Data Exchange (ETDEWEB)

    Keiser, J.R.; Taljat, B.; Wang, X.L. [and others

    1997-08-01

    Cracking of the stainless steel layer in co-extruded 304L/SA210 tubing used in black liquor recovery boilers is being found in an ever-increasing number of North American pulp and paper mills. Because of the possibility of a tube failure, this is a significant safety issue, and, because of the extra time required for tube inspection and repair, this can become an economic issue as well. In a project funded by the U.S. Department of Energy and given wide support among paper companies, boiler manufacturers, and tube fabricators, studies are being conducted to determine the cause of the cracking and to identify alternate materials and/or operating procedures to prevent tube cracking. Examination of cracked tubes has permitted characterization of crack features, and transmission electron microscopy is providing information about the thermal history, particularly cyclic thermal exposures, that tubes have experienced. Neutron and x-ray diffraction techniques are being used to determine the residual stresses in as-fabricated tube panels and exposed tubes, and finite element modeling is providing information about the stresses the tubes experience during operation. Laboratory studies are being conducted to determine the susceptibility of the co-extruded 304L/SA210 tubes to stress corrosion cracking, thermal fatigue, and corrosion in molten smelt. This paper presents the current status of these studies. On the basis of all of these studies, recommendations for means to prevent tube cracking will be offered.

  20. Present status of JRR-3 neutron guide tubes

    International Nuclear Information System (INIS)

    JRR-3 reactor is a research reactor of 20 MW, and its main use is neutron beam experiments. Aiming at effective and efficient utilization, neutron guide tubes were introduced in 1990. Neutron guide tubes consist of 2 tubes for hot neutrons and 3 tubes for cold neutrons, and they are laid up to the beam hall adjacent to the reactor building. This allows the installation of about 20 experimental devices, and a wide variety of researches are carried out using these devices. To achieve higher performance of these neutron guide tubes, the updating to supermirror with high neutron transport efficiency is under way. As for the hot neutron guide tubes, hot neutron intensity has become approximately 6 times until now, which realized a large extent of efficiency. On the other hand, the soundness of the equipment has become a major issue after the Great East Japan Earthquake. This paper reports the confirmation of the soundness of neutron guide tubes, contents of restoration work, and current situation after the restoration work. (A.O.)

  1. Steam generator tubing NDE performance

    Energy Technology Data Exchange (ETDEWEB)

    Henry, G. [Electric Power Research Institute, Charlotte, NC (United States); Welty, C.S. Jr. [Electric Power Research Institute, Palo Alto, CA (United States)

    1997-02-01

    Steam generator (SG) non-destructive examination (NDE) is a fundamental element in the broader SG in-service inspection (ISI) process, a cornerstone in the management of PWR steam generators. Based on objective performance measures (tube leak forced outages and SG-related capacity factor loss), ISI performance has shown a continually improving trend over the years. Performance of the NDE element is a function of the fundamental capability of the technique, and the ability of the analysis portion of the process in field implementation of the technique. The technology continues to improve in several areas, e.g. system sensitivity, data collection rates, probe/coil design, and data analysis software. With these improvements comes the attendant requirement for qualification of the technique on the damage form(s) to which it will be applied, and for training and qualification of the data analysis element of the ISI process on the field implementation of the technique. The introduction of data transfer via fiber optic line allows for remote data acquisition and analysis, thus improving the efficiency of analysis for a limited pool of data analysts. This paper provides an overview of the current status of SG NDE, and identifies several important issues to be addressed.

  2. Steam generator tubing NDE performance

    International Nuclear Information System (INIS)

    Steam generator (SG) non-destructive examination (NDE) is a fundamental element in the broader SG in-service inspection (ISI) process, a cornerstone in the management of PWR steam generators. Based on objective performance measures (tube leak forced outages and SG-related capacity factor loss), ISI performance has shown a continually improving trend over the years. Performance of the NDE element is a function of the fundamental capability of the technique, and the ability of the analysis portion of the process in field implementation of the technique. The technology continues to improve in several areas, e.g. system sensitivity, data collection rates, probe/coil design, and data analysis software. With these improvements comes the attendant requirement for qualification of the technique on the damage form(s) to which it will be applied, and for training and qualification of the data analysis element of the ISI process on the field implementation of the technique. The introduction of data transfer via fiber optic line allows for remote data acquisition and analysis, thus improving the efficiency of analysis for a limited pool of data analysts. This paper provides an overview of the current status of SG NDE, and identifies several important issues to be addressed

  3. Conditioning and breakdown phenomena in accelerator tubes

    International Nuclear Information System (INIS)

    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

  4. Vidicon storage tube electrical input/output

    Science.gov (United States)

    Lipoma, P.

    1972-01-01

    Electrical data storage tube is assembled from standard vidicon tube using conventional amplification and control circuits. Vidicon storage tube is simple, inexpensive and has an erase and preparation time of less than 5 microseconds.

  5. A new ultrasonic inspection system for non-destructive examination of precision tubes

    International Nuclear Information System (INIS)

    A system based upon a rotating water chamber with eight ultrasonic transducers is described which has been designed for the fast, stringent and automatic inspection of the dimensions of, and defects in, precision tubes such as those used for fuel encapsulation in water-cooled nuclear reactors. The principles incorporated in the system are summarized as follows; both dimension and defect measurements are made using the same system, an ultrasonic pulse-echo technique is used which requires no contacts, measurements of inner diameters are made from the outside of the tube, the spiral scan used is achieved by rotating the transducers instead of rotating the tubes, and results are registered and evaluated by computer. Evaluation and development work on the system that has been carried out, based on practical tube inspection experience, is described. (U.K.)

  6. Eddy sensors for small diameter stainless steel tubes.

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, Jack L.; Morales, Alfredo Martin; Grant, J. Brian; Korellis, Henry James; LaFord, Marianne Elizabeth; Van Blarigan, Benjamin; Andersen, Lisa E.

    2011-08-01

    The goal of this project was to develop non-destructive, minimally disruptive eddy sensors to inspect small diameter stainless steel metal tubes. Modifications to Sandia's Emphasis/EIGER code allowed for the modeling of eddy current bobbin sensors near or around 1/8-inch outer diameter stainless steel tubing. Modeling results indicated that an eddy sensor based on a single axial coil could effectively detect changes in the inner diameter of a stainless steel tubing. Based on the modeling results, sensor coils capable of detecting small changes in the inner diameter of a stainless steel tube were designed, built and tested. The observed sensor response agreed with the results of the modeling and with eddy sensor theory. A separate limited distribution SAND report is being issued demonstrating the application of this sensor.

  7. A novel photomultiplier tube for calorimetry at the SSC

    International Nuclear Information System (INIS)

    A silicon target photomultiplier tube with an anode consisting of a large area Avalanche Photodiode (APD) has been developed. The tube combines the advantages of an avalanche photodiode, excellent linearity and large dynamic range, with the properties of a phototube. The tube structure is proximity focussing, which is not affected by high magnetic fields approximately aligned with the axis. The high linearity makes this device attractive for calorimetry at the SSC. The extension of this concept to an APD array will provide a cost effective fiber readout for both digital (tracking) and analogue applications. A tube equipped with an APD array is being developed currently as a readout option for the SDC Shower Maximum Detector

  8. The Choking Game on YouTube: An Update.

    Science.gov (United States)

    Defenderfer, Ellen K; Austin, Jillian E; Davies, W Hobart

    2016-01-01

    The choking game (TCG) is an adolescent activity in which asphyxiation is used to obtain a "high," occasionally resulting in seizures or death. A plethora of TCG information is available through YouTube, though this content has not been evaluated recently. The current study described TCG as portrayed in YouTube videos and compared views and ratings of TCG videos to unrelated videos. The TCG videos demonstrated diverse methods of asphyxiation, with a minority showing injury to the participants. TCG videos were less likely to be commented on or rated positively than non-choking game videos. TCG prevention videos differed significantly from actual TCG videos in the way they depicted the social context of TCG. Thus, TCG videos are accessible through YouTube, but the prevention materials available on YouTube are not accurate or representative. Accurate and educational online prevention materials should be created to decrease the occurrence of TCG.

  9. The Choking Game on YouTube: An Update.

    Science.gov (United States)

    Defenderfer, Ellen K; Austin, Jillian E; Davies, W Hobart

    2016-01-01

    The choking game (TCG) is an adolescent activity in which asphyxiation is used to obtain a "high," occasionally resulting in seizures or death. A plethora of TCG information is available through YouTube, though this content has not been evaluated recently. The current study described TCG as portrayed in YouTube videos and compared views and ratings of TCG videos to unrelated videos. The TCG videos demonstrated diverse methods of asphyxiation, with a minority showing injury to the participants. TCG videos were less likely to be commented on or rated positively than non-choking game videos. TCG prevention videos differed significantly from actual TCG videos in the way they depicted the social context of TCG. Thus, TCG videos are accessible through YouTube, but the prevention materials available on YouTube are not accurate or representative. Accurate and educational online prevention materials should be created to decrease the occurrence of TCG. PMID:27335992

  10. Design and optimization of the low frequency eddy current technique for the volumetric inspection of austenitic small diameter tubes with a wall thickness up to 12 mm; Auslegung und Optimierung des Niederfrequenz-Wirbelstrom-Verfahrens fuer die volumetrische Pruefung von austenitischen Neben- und Kleinleitungen mit Wandstaerken bis 12 mm

    Energy Technology Data Exchange (ETDEWEB)

    Becker, R.; Bessert, S.; Disque, M.; Weiss, R. [Fraunhofer-Institut fuer Zerstoerungsfreie Pruefverfahren, Saarbruecken (Germany)

    1998-11-01

    The low-frequency eddy current technique discussed is a suitable external inspection technique detecting defects at the inner walls of small-diameter tubes and measuring their depths via the ligament. A testing system with optimized sensor lus software for image recording, evaluation, display and documentation is available. The current state of development of the system permits detection and measurement of defects up to 20 mm in size in austenitic inner walls 12.5 mm thick down to a depth of 3 mm. This applies both to the homogenous base metal and the weld with {delta} ferrite. (orig./CB) [Deutsch] Das vorgestellte Niederfrequenz-Wirbelstrom-Verfahren ist geeignet, bei Pruefung von aussen Fehler an der Innenseite von Klein- und Nebenleitungen nachzuweisen und ueber das Ligament deren Tiefe zu bestimmen. Ein entsprechendes Pruefsystem mit optimiertem Sensor und der Software zur Aufnahme, Auswertung, Darstellung und Dokumentation der Wirbelstrom-Urdaten steht zur Verfuegung. Beim jetzigen Entwicklungsstand liegt die Nachweisgrenze fuer einen 20 mm langen Innenfehler in einer 12.5 mm dicken austenitischen Wandung bei einer Fehlertiefe von 3 mm. Dies gilt sowohl fuer den homogenen Grundwerkstoff als auch fuer Schweissgefuege mit {delta}-Ferrit. (orig./MM)

  11. 核电站蒸汽发生器传热管涡流检验数据库的设计与实现%The Database Design and Implement of Eddy Current Inspection for Nuclear Power Plant Steam Generator Tubes

    Institute of Scientific and Technical Information of China (English)

    贝雅耀; 宋涛; 王小刚; 孔玉莹; 吴刚; 赵磊; 韩长字

    2012-01-01

    In order to offer guidelines for establishing the eddy current inspection database applicable for the situation of domestic nuclear power units, this paper discussed the database design and implement of eddy current inspection for nuclear power plant steam generator tubes based on ORACLE. Mainly this paper introduced the necessity of establishing the database of eddy current inspection, the approach of database design and implement, and several typical application examples. The thorough structure of eddy current inspection database could be established by utilizing the "The First Normal Form" of database design principles, and the data insertion, updating, deletion and query could be done using SQL Plus tool or client interface written by programming language%为建立适合国内核电机组的蒸汽发生器传热管涡流检验数据库,以ORACLE平台为基础,讨论了数据库的设计与实现。主要介绍了建立涡流检验数据库的必要性及数据库设计与实现的思路,并以现有的数据为对象列举了几个有代表性的应用实例。结果表明,利用数据库设计的“第一范式”的规则可以建立一个组织完善的涡流检验数据库结构,数据的插入、更新、删除及查询可通过SQL Plus工具或用编程语言设计的客户端实现。

  12. Masked Priming Effects in Aphasia: Evidence of Altered Automatic Spreading Activation

    Science.gov (United States)

    Silkes, JoAnn P.; Rogers, Margaret A.

    2012-01-01

    Purpose: Previous research has suggested that impairments of automatic spreading activation may underlie some aphasic language deficits. The current study further investigated the status of automatic spreading activation in individuals with aphasia as compared with typical adults. Method: Participants were 21 individuals with aphasia (12 fluent, 9…

  13. Automatic quantification of subarachnoid hemorrhage on noncontrast CT

    NARCIS (Netherlands)

    Boers, A.M.; Zijlstra, I.A.; Gathier, C.S.; Berg, van den R.; Slump, C.H.; Marquering, H.A.; Majoie, C.B.

    2014-01-01

    Quantification of blood after SAH on initial NCCT is an important radiologic measure to predict patient outcome and guide treatment decisions. In current scales, hemorrhage volume and density are not accounted for. The purpose of this study was to develop and validate a fully automatic method for SA

  14. How Things Work: Light, Dark, or Burned? Two Automatic Toasters.

    Science.gov (United States)

    Crane, H. Richard, Ed.

    1984-01-01

    Discusses the operation of two automatic toasters, comparing and contrasting an old Sunbeam model (approximately 20 years old) with a Proctor-Silex, a model currently being sold. Includes schematic representation of parts of the Sunbeam and schematic of essential parts and circuit diagram of the Proctor-Silex. (JN)

  15. Electronic components, tubes and transistors

    CERN Document Server

    Dummer, G W A

    1965-01-01

    Electronic Components, Tubes and Transistors aims to bridge the gap between the basic measurement theory of resistance, capacitance, and inductance and the practical application of electronic components in equipments. The more practical or usage aspect of electron tubes and semiconductors is given emphasis over theory. The essential characteristics of each main type of component, tube, and transistor are summarized. This book is comprised of six chapters and begins with a discussion on the essential characteristics in terms of the parameters usually required in choosing a resistor, including s

  16. 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.

  17. 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. PMID:26016095

  18. Automatic mapping of monitoring data

    DEFF Research Database (Denmark)

    Lophaven, Søren; Nielsen, Hans Bruun; Søndergaard, Jacob

    2005-01-01

    This paper presents an approach, based on universal kriging, for automatic mapping of monitoring data. The performance of the mapping approach is tested on two data-sets containing daily mean gamma dose rates in Germany reported by means of the national automatic monitoring network (IMIS......). In the second dataset an accidental release of radioactivity in the environment was simulated in the South-Western corner of the monitored area. The approach has a tendency to smooth the actual data values, and therefore it underestimates extreme values, as seen in the second dataset. However, it is capable...

  19. Annual review in automatic programming

    CERN Document Server

    Goodman, Richard

    2014-01-01

    Annual Review in Automatic Programming focuses on the techniques of automatic programming used with digital computers. Topics covered range from the design of machine-independent programming languages to the use of recursive procedures in ALGOL 60. A multi-pass translation scheme for ALGOL 60 is described, along with some commercial source languages. The structure and use of the syntax-directed compiler is also considered.Comprised of 12 chapters, this volume begins with a discussion on the basic ideas involved in the description of a computing process as a program for a computer, expressed in

  20. Algorithms for skiascopy measurement automatization

    Science.gov (United States)

    Fomins, Sergejs; Trukša, Renārs; KrūmiĆa, Gunta

    2014-10-01

    Automatic dynamic infrared retinoscope was developed, which allows to run procedure at a much higher rate. Our system uses a USB image sensor with up to 180 Hz refresh rate equipped with a long focus objective and 850 nm infrared light emitting diode as light source. Two servo motors driven by microprocessor control the rotation of semitransparent mirror and motion of retinoscope chassis. Image of eye pupil reflex is captured via software and analyzed along the horizontal plane. Algorithm for automatic accommodative state analysis is developed based on the intensity changes of the fundus reflex.

  1. Automatic Construction of Finite Algebras

    Institute of Scientific and Technical Information of China (English)

    张健

    1995-01-01

    This paper deals with model generation for equational theories,i.e.,automatically generating (finite)models of a given set of (logical) equations.Our method of finite model generation and a tool for automatic construction of finite algebras is described.Some examples are given to show the applications of our program.We argue that,the combination of model generators and theorem provers enables us to get a better understanding of logical theories.A brief comparison betwween our tool and other similar tools is also presented.

  2. Automatic spectrophotometric determination of trace amounts of boron with curcumin

    International Nuclear Information System (INIS)

    The proposed method utilizes a rosocyanin complex formed by the reaction of boric acid and curcumin without evaporation to dryness. The automatic determination of boron in aqueous solution is performed according to the predetermined program (Fig. 8), after manual injection of a sample solution (2.00 ml) to the reaction vessel. Glacial acetic acid (5.40 ml) and propionic anhydride (13.20 ml) are added and the solution is circulated through the circulating pipe consisting of a bubble remover, an absorbance measuring flow cell, an air blowing tube and a drain valve. Oxalyl chloride (0.81 ml) is added and the solution is circulated for 80 seconds to eliminate water. Sulfuric acid (1.08 ml) and curcumin reagent (3.01 ml) are added and the solution is circulated for 120 seconds to form a rosocyanin complex. After addition of an acetate buffer solution (21.34 ml) for the neutralisation of an interfering proton complex of curcumin, the absorbance of the orange solution is measured at 545 nm. This automatic analysis is sensitive (Fig. 9) and rapid; less than 1.5 μg of boron is determined in 7 minutes. It can be applied to the determination of trace amounts of boron in steel samples, combined with an automatic distillation under development. (auth.)

  3. Tailoring automatic exposure control toward constant detectability in digital mammography

    Energy Technology Data Exchange (ETDEWEB)

    Salvagnini, Elena, E-mail: elena.salvagnini@uzleuven.be [Department of Imaging and Pathology, Medical Physics and Quality Assessment, KUL, Herestraat 49, Leuven B-3000, Belgium and SCK-CEN, Boeretang 200, Mol 2400 (Belgium); Bosmans, Hilde [Department of Imaging and Pathology, Medical Physics and Quality Assessment, KUL, Herestraat 49, Leuven B-3000, Belgium and Department of Radiology, UZ Gasthuisberg, Herestraat 49, Leuven B-3000 (Belgium); Struelens, Lara [SCK-CEN, Boeretang 200, Mol 2400 (Belgium); Marshall, Nicholas W. [Department of Radiology, UZ Gasthuisberg, Herestraat 49, Leuven B-3000 (Belgium)

    2015-07-15

    Purpose: The automatic exposure control (AEC) modes of most full field digital mammography (FFDM) systems are set up to hold pixel value (PV) constant as breast thickness changes. This paper proposes an alternative AEC mode, set up to maintain some minimum detectability level, with the ultimate goal of improving object detectability at larger breast thicknesses. Methods: The default “OPDOSE” AEC mode of a Siemens MAMMOMAT Inspiration FFDM system was assessed using poly(methyl methacrylate) (PMMA) of thickness 20, 30, 40, 50, 60, and 70 mm to find the tube voltage and anode/filter combination programmed for each thickness; these beam quality settings were used for the modified AEC mode. Detectability index (d′), in terms of a non-prewhitened model observer with eye filter, was then calculated as a function of tube current-time product (mAs) for each thickness. A modified AEC could then be designed in which detectability never fell below some minimum setting for any thickness in the operating range. In this study, the value was chosen such that the system met the achievable threshold gold thickness (T{sub t}) in the European guidelines for the 0.1 mm diameter disc (i.e., T{sub t} ≤ 1.10 μm gold). The default and modified AEC modes were compared in terms of contrast-detail performance (T{sub t}), calculated detectability (d′), signal-difference-to-noise ratio (SDNR), and mean glandular dose (MGD). The influence of a structured background on object detectability for both AEC modes was examined using a CIRS BR3D phantom. Computer-based CDMAM reading was used for the homogeneous case, while the images with the BR3D background were scored by human observers. Results: The default OPDOSE AEC mode maintained PV constant as PMMA thickness increased, leading to a reduction in SDNR for the homogeneous background 39% and d′ 37% in going from 20 to 70 mm; introduction of the structured BR3D plate changed these figures to 22% (SDNR) and 6% (d′), respectively

  4. Heat Exchanger Tube Inspection of Nuclear Power Plants using IRIS Technique

    International Nuclear Information System (INIS)

    Inspection of heat exchange tubing include steam generator of nuclear power plant mostly performed with eddy current method. Recently, various inspection technique is available such as remote field eddy current, flux leakage and ultrasonic methods. Each of these techniques has its merits and limitations. Electromagnetic techniques are very useful to locate areas of concern but sizing is hard because of the difficult interpretation of an electric signature. On the other hand, ultrasonic methods are very accurate in measuring wall loss damage, and are reliable for detecting cracks. Additionally ultrasound methods is not affected by support plates or tube sheets and variation of electrical conductivity or permeability. Ultrasound data is also easier to analyze since the data displayed is generally the remaining wall thickness. It should be emphasized that ultrasound is an important tool for sizing defects in tubing. In addition, it can be used in situations where eddy current or remote field eddy current is not reliable, or as a flaw assessment tool to supplement the electromagnetic data. The need to develop specialized ultrasonic tools for tubing inspection was necessary considering the limitations of electromagnetic techniques to some common inspection problems. These problems the sizing of wall loss in carbon steel tubes near the tube sheet or support plate, sizing internal erosion damage, and crack detection. This paper will present an IRIS(Internal Rotating Inspection System) ultrasonic tube inspection technique for heat exchanger tubing in nuclear power plant and verify inspection reliability for artificial flaw embedded to condenser tube

  5. On Poor Separation in Magnetically Driven Shock Tube

    DEFF Research Database (Denmark)

    Chang, C.T.

    1973-01-01

    Observations made at steady-state running conditions in a magnetically driven shock tube, with parallel-plate electrodes, showed that for a given discharge voltage, sufficient separation between the shock and the current-sheet occurred only at relatively high discharge pressures. As a comparison......, poor separations were also noted in conventional diaphragm-type shock tubes running at low initial pressures. It is demonstrated that the observed poor separation can be explained by a mass leakage, instead of through the wall boundary layer, but through the current-sheet itself....

  6. High accurate thickness gauge system of zirconium and Zircaloy-2 layers for zirconium liner cladding tubes

    International Nuclear Information System (INIS)

    In boiling water reactors, zirconium(Zr)-Zircaloy cladding tubes have been put into practice for lengthening a life cycle of the cladding tube. The cladding tube is a duplex tube with an inner layer of pure Zr bonded to Zircaloy-2 layer metallurgically. The assurance of the inner and outer layer thickness is essential for a reliability of the cladding tube. A new thickness gauge system in the manufacturing process has been developed to measure the thickness of each layer over an entire tube length instead of the conventional microscopic viewing method. This system uses an eddy current method and an ultrasonic method. In this paper, the quantitative analysis of undesirable factors in eddy current method and the signal processing method for accurate measurement are described. The outline of fully automated thickness gauge system is also reported

  7. A Device for Automatically Measuring and Supervising the Critical Care Patient’S Urine Output

    Directory of Open Access Journals (Sweden)

    Roemi Fernández

    2010-01-01

    Full Text Available Critical care units are equipped with commercial monitoring devices capable of sensing patients’ physiological parameters and supervising the achievement of the established therapeutic goals. This avoids human errors in this task and considerably decreases the workload of the healthcare staff. However, at present there still is a very relevant physiological parameter that is measured and supervised manually by the critical care units’ healthcare staff: urine output. This paper presents a patent-pending device capable of automatically recording and supervising the urine output of a critical care patient. A high precision scale is used to measure the weight of a commercial urine meter. On the scale’s pan there is a support frame made up of Bosch profiles that isolates the scale from force transmission from the patient’s bed, and guarantees that the urine flows properly through the urine meter input tube. The scale’s readings are sent to a PC via Bluetooth where an application supervises the achievement of the therapeutic goals. The device is currently undergoing tests at a research unit associated with the University Hospital of Getafe in Spain.

  8. Individualized volume CT dose index determined by cross-sectional area and mean density of the body to achieve uniform image noise of contrast-enhanced pediatric chest CT obtained at variable kV levels and with combined tube current modulation

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Hyun Woo [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul (Korea, Republic of)

    2011-07-15

    A practical body-size adaptive protocol providing uniform image noise at various kV levels is not available for pediatric CT. To develop a practical contrast-enhanced pediatric chest CT protocol providing uniform image noise by using an individualized volume CT dose index (CTDIvol) determined by the cross-sectional area and density of the body at variable kV levels and with combined tube current modulation. A total of 137 patients (mean age, 7.6 years) underwent contrast-enhanced pediatric chest CT based on body weight. From the CTDIvol, image noise, and area and mean density of the cross-section at the lung base in the weight-based group, the best fit equation was estimated with a very high correlation coefficient ({gamma}{sup 2} = 0.86, P < 0.001). For the next study, 177 patients (mean age, 7.9 years; the CTDIvol group) underwent contrast-enhanced pediatric chest CT with the CTDIvol determined individually by the best fit equation. CTDIvol values on the dose report after CT scanning, noise differences from the target noise, areas, and mean densities were compared between these two groups. The CTDIvol values (mean{+-}standard deviation, 1.6 {+-} 0.7 mGy) and the noise differences from the target noise (1.1 {+-} 0.9 HU) of the CTDIvol group were significantly lower than those of the weight-based group (2.0 {+-} 1.0 mGy, 1.8 {+-} 1.4 HU) (P < 0.001). In contrast, no statistically significant difference was found in area (317.0 {+-} 136.8 cm{sup 2} vs. 326.3 {+-} 124.8 cm{sup 2}), mean density (-212.9 {+-} 53.1 HU vs. -221.1 {+-} 56.3 HU), and image noise (13.8 {+-} 2.3 vs. 13.6 {+-} 1.7 HU) between the weight-based and the CTDIvol groups (P > 0.05). Contrast-enhanced pediatric chest CT with the CTDIvol determined individually by the cross-sectional area and density of the body provides more uniform noise and better dose adaptation to body habitus than does weight-based CT at variable kV levels and with combined tube current modulation. (orig.)

  9. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... Funding Division of Extramural Activities Division of Extramural Science Programs Funding Opportunity Announcements Funding Mechanisms Supported by ... Amaurosis Low Vision Refractive Errors Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia NEI ...

  10. Lunar Core Drive Tubes Summary

    Data.gov (United States)

    National Aeronautics and Space Administration — Contains a brief summary and high resolution imagery from various lunar rock and core drive tubes collected from the Apollo and Luna missions to the moon.

  11. 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 NEI ...

  12. drift tube for linear accelerator

    CERN Multimedia

    A drift tube from the Linac 1. This was the first tank of the linear accelerator Linac1, the injection system for the Proton Synchrotron, It ran for 34 years (1958 - 1992). Protons entered at the far end and were accelerated between the copper drift tubes by an oscillating electromagnetic field. The field flipped 200 million times a second (200 MHz) so the protons spent 5 nanoseconds crossing a drift tube and a gap. Moving down the tank, the tubes and gaps had to get longer as the protons gained speed. The tank accelerated protons from 500 KeV to 10 MeV. Linac1 was also used to accelerate deutrons and alpha particles for the Intersecting Storage Rings and oxygen and sulpher ions for the Super Proton Synchrotron heavy ion programme.

  13. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... Funding Division of Extramural Affairs Division of Extramural Science Programs Funding Opportunity Announcements Funding Mechanisms Supported by ... Amaurosis Low Vision Refractive Errors Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia NEI ...

  14. Closed bore XMR (CBXMR) systems for aortic valve replacement: Active magnetic shielding of x-ray tubes

    Energy Technology Data Exchange (ETDEWEB)

    Bracken, John A.; DeCrescenzo, Giovanni; Komljenovic, Philip; Lillaney, Prasheel V.; Fahrig, Rebecca; Rowlands, J. A. [Department of Medical Biophysics and Sunnybrook Health Sciences Center, University of Toronto, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5 (Canada); Department of Radiology, Stanford University, Stanford, California 94305 (United States); Department of Medical Biophysics and Sunnybrook Health Sciences Center, University of Toronto, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5 (Canada)

    2009-05-15

    Hybrid closed bore x-ray/MRI systems are being developed to improve the safety and efficacy of percutaneous aortic valve replacement procedures by harnessing the complementary strengths of the x-ray and MRI modalities in a single interventional suite without requiring patient transfer between two rooms. These systems are composed of an x-ray C-arm in close proximity ({approx_equal}1 m) to an MRI scanner. The MRI magnetic fringe field can cause the electron beam in the x-ray tube to deflect. The deflection causes the x-ray field of view to shift position on the detector receptacle. This could result in unnecessary radiation exposure to the patient and the staff in the cardiac catheterization laboratory. Therefore, the electron beam deflection must be corrected. The authors developed an active magnetic shielding system that can correct for electron beam deflection to within an accuracy of 5% without truncating the field of view or increasing exposure to the patient. This system was able to automatically adjust to different field strengths as the external magnetic field acting on the x-ray tube was changed. Although a small torque was observed on the shielding coils of the active shielding system when they were placed in a magnetic field, this torque will not impact their performance if they are securely mounted on the x-ray tube and the C-arm. The heating of the coils of the shielding system for use in the clinic caused by electric current was found to be slow enough not to require a dedicated cooling system for one percutaneous aortic valve replacement procedure. However, a cooling system will be required if multiple procedures are performed in one session.

  15. Closed bore XMR (CBXMR) systems for aortic valve replacement: active magnetic shielding of x-ray tubes.

    Science.gov (United States)

    Bracken, John A; DeCrescenzo, Giovanni; Komljenovic, Philip; Lillaney, Prasheel V; Fahrig, Rebecca; Rowlands, J A

    2009-05-01

    Hybrid closed bore x-ray/MRI systems are being developed to improve the safety and efficacy of percutaneous aortic valve replacement procedures by harnessing the complementary strengths of the x-ray and MRI modalities in a single interventional suite without requiring patient transfer between two rooms. These systems are composed of an x-ray C-arm in close proximity (approximately 1 m) to an MRI scanner. The MRI magnetic fringe field can cause the electron beam in the x-ray tube to deflect. The deflection causes the x-ray field of view to shift position on the detector receptacle. This could result in unnecessary radiation exposure to the patient and the staff in the cardiac catheterization laboratory. Therefore, the electron beam deflection must be corrected. The authors developed an active magnetic shielding system that can correct for electron beam deflection to within an accuracy of 5% without truncating the field of view or increasing exposure to the patient. This system was able to automatically adjust to different field strengths as the external magnetic field acting on the x-ray tube was changed. Although a small torque was observed on the shielding coils of the active shielding system when they were placed in a magnetic field, this torque will not impact their performance if they are securely mounted on the x-ray tube and the C-arm. The heating of the coils of the shielding system for use in the clinic caused by electric current was found to be slow enough not to require a dedicated cooling system for one percutaneous aortic valve replacement procedure. However, a cooling system will be required if multiple procedures are performed in one session. PMID:19544789

  16. Corrosion of evaporator tubes in low emission steam boilers

    Directory of Open Access Journals (Sweden)

    S. Topolska

    2010-04-01

    air curtain between reducing environment and tubes surface. These efforts often are insufficient. The replacement of more corrosion resistant material on Cr rich steel or Cr-Ni steel is possible but other problems appear connected with high costs of installation and low heat transfer coefficients of such materials. Knowing the mechanisms of corrosion allows adjusting combustion process at low emission steam boilers.Originality/value: Information available in literature does not clearly indicate what mechanism of corrosion is dominant at different parts of combustion chamber. The current study shows which corrosion mechanisms are the most dangerous for evaporator tubes.

  17. 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...

  18. Duplication of the fallopian tube

    Directory of Open Access Journals (Sweden)

    R Narayanan

    2008-01-01

    Full Text Available Hysterosalpingography accurately delineates the uterine and tubal lumen, and hence is routinely performed for the evaluation of infertility.We observed a case of infertility where uterine cavity was normal but fallopian tubes were bifurcated at the ampullary region. Mullerian duct anomalies are reported in literature, but maldevelopment of fallopian tube in isolation is rare. This abnormality can present as infertility, ectopic pregnancy, in association with urinary tract anomalies or as failure of sterilisation method.

  19. Test-tube Baby Option

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    As China’s first test tube baby celebrates her 20th birthday,the country is moving to improve IVF procedures I feel just like a normal person,despite being a little bit hi-tech,"said China’s first test-tube baby Zheng Mengzhu at her birthday party in Beijing. Zheng,born on March 10,1988 in the No.3 Hospital affiliated to the Peking University of Medical Sciences,made a trip

  20. Automatic Identification of Metaphoric Utterances

    Science.gov (United States)

    Dunn, Jonathan Edwin

    2013-01-01

    This dissertation analyzes the problem of metaphor identification in linguistic and computational semantics, considering both manual and automatic approaches. It describes a manual approach to metaphor identification, the Metaphoricity Measurement Procedure (MMP), and compares this approach with other manual approaches. The dissertation then…

  1. Automatically Preparing Safe SQL Queries

    Science.gov (United States)

    Bisht, Prithvi; Sistla, A. Prasad; Venkatakrishnan, V. N.

    We present the first sound program source transformation approach for automatically transforming the code of a legacy web application to employ PREPARE statements in place of unsafe SQL queries. Our approach therefore opens the way for eradicating the SQL injection threat vector from legacy web applications.

  2. The Automatic Measurement of Targets

    DEFF Research Database (Denmark)

    Höhle, Joachim

    1997-01-01

    The automatic measurement of targets is demonstrated by means of a theoretical example and by an interactive measuring program for real imagery from a réseau camera. The used strategy is a combination of two methods: the maximum correlation coefficient and the correlation in the subpixel range...

  3. Automatic quantification of iris color

    DEFF Research Database (Denmark)

    Christoffersen, S.; Harder, Stine; Andersen, J. D.;

    2012-01-01

    An automatic algorithm to quantify the eye colour and structural information from standard hi-resolution photos of the human iris has been developed. Initially, the major structures in the eye region are identified including the pupil, iris, sclera, and eyelashes. Based on this segmentation, the ...

  4. Automatic Association of News Items.

    Science.gov (United States)

    Carrick, Christina; Watters, Carolyn

    1997-01-01

    Discussion of electronic news delivery systems and the automatic generation of electronic editions focuses on the association of related items of different media type, specifically photos and stories. The goal is to be able to determine to what degree any two news items refer to the same news event. (Author/LRW)

  5. Automatic milking : a better understanding

    NARCIS (Netherlands)

    Meijering, A.; Hogeveen, H.; Koning, de C.J.A.M.

    2004-01-01

    In 2000 the book Robotic Milking, reflecting the proceedings of an International Symposium which was held in The Netherlands came out. At that time, commercial introduction of automatic milking systems was no longer obstructed by technological inadequacies. Particularly in a few west-European countr

  6. Development of Remote Weld Testing Technique for Moisture Separator and Reheater Tubes in Nuclear Power Plants

    International Nuclear Information System (INIS)

    The heat exchanger tube in nuclear power plants is mainly fabricated from nonferromagnetic material such as a copper, titanium, and inconel alloy, but the moisture separator and reheater tube in the turbine system is fabricated from ferromagnetic material such as a carbon steel or ferrite stainless steel which has a good mechanical properties in harsh environments of high pressure and temperature. Especially, the moisture separator and reheater tubes, which use steam as a heat transfer media, typically employ a tubing with integral fins to furnish higher heat transfer rates. The ferromagnetic tube typically shows superior properties in high pressure and temperature environments than a nonferromagnetic material, but can make a trouble during the normal operation of power plants because the ferrous tube has service-induced damage forms including a steam cutting, erosion, mechanical wear, stress corrosion cracking, etc. Therefore, nondestructive examination is periodically performed to evaluate the tube integrity. Now, the remote field testing(RFT) technique is one of the solution for examination of ferromagnetic tube because the conventional eddy current technique typically can not be applied to ferromagnetic tube such as a ferrite stainless steel due to the high electrical permeability of ferrous tube. In this study, we have designed RFT probes, calibration standards, artificial flaw specimen, and probe pusher-puller necessary for field application, and have successfully carry out RFT examination of the moisture separator and reheater tube of nuclear power plants.

  7. 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.

  8. A laser tube position regulator

    Energy Technology Data Exchange (ETDEWEB)

    Sinyitiro, A.; Norio, K.

    1984-03-26

    An improved design is patented for a mechanism and method of regulating, with a high degree of accuracy, the position of a laser tube in a gas laser inside the optical resonator formed by external mirrors. The laser tube is held in two holders. Each holder contains an L shaped bracket which supports a semitransparent plate. The plate is positioned so that its center is over the center of the end of the tube which is in the form of a Brewster window. A narrow parallel beam is directed along the tube axis from an external auxiliary laser. The beam passes through the semitransparent mirror of the optical resonator in the adjusted laser, through the first Brewster window, the tube itself, and the second Brewster window and is reflected back in the reverse direction from a fully reflecting mirror in the optical resonator. This provides partial reflection of the beam from the external Brewster mirror surface. The tube position in the holders is regulated continuously so that the luminous spots from the beams reflected off the Brewster windows fall on the semitransparent plates in the center of the latter which is designated as the point of intersection.

  9. Transcorneal tube erosion of an Ahmed valve implant in an adult

    Directory of Open Access Journals (Sweden)

    Al-Shahwan Sami

    2010-01-01

    Full Text Available Ahmed valve implants are currently used to manage high-risk complicated adults and pediatric glaucoma when standard filtration surgery is unsuccessful. Despite its success, the Ahmed valve shunt has significant complications particularly in the anterior segment. We report an unusual case of transcorneal tube erosion of an Ahmed valve implant in an adult that resulted from long-standing tube-corneal touch. Periodic observation of tube position is recommended.

  10. An experimental investigation into crushing behavior of radially stiffened GFRP composite tubes

    OpenAIRE

    Mahdi, E.; Sebaey, T.A.

    2014-01-01

    State-of-the-art studies of the crushing of composite tubes reveal different factors affecting their crashworthiness. Of those factors, the geometrical property of the tube is of great interest. In the current study, four different categories of tube cross-sectional geometrical properties were tested under a quasi-static crushing scenario to investigate the best cross-section in terms of the crushing load and the energy-absorption capacities. A woven GFRP consisting of eight layers was used t...

  11. Design and implementation of a control system to improve the quality of the combustion gases in the fire-tube boiler of 5 BHP

    Directory of Open Access Journals (Sweden)

    Carlos Alfredo Pérez Albán

    2016-06-01

    Full Text Available The goal of this paper is the design and implementation of a system for controlling the quality of the combustion gases in a fire-tube boiler of 5 BHP. Based on the percentage of O2 present in the combustion gases, measured by a lambda sensor, the percentage of CO2 emitted into the atmosphere is determined. PID proportional control is responsible for the automatic regulation of the entry of air to the boiler by an actuator, according to the percentage of the oxygen concentration in the combustion gases. The control system has an HMI display and a modular PLC. The results achieved ensure pollutant gases emissions within the parameters established by current environmental standards, achieving the required quality of combustion gases and reducing the fuel consumption of the boiler.

  12. Sign language perception research for improving automatic sign language recognition

    OpenAIRE

    Ten Holt, G.A.; Arendsen, J.; De Ridder, H.; Van Doorn, A.J.; Reinders, M.J.T.; Hendriks, E.A.

    2009-01-01

    Current automatic sign language recognition (ASLR) seldom uses perceptual knowledge about the recognition of sign language. Using such knowledge can improve ASLR because it can give an indication which elements or phases of a sign are important for its meaning. Also, the current generation of data-driven ASLR methods has shortcomings which may not be solvable without the use of knowledge on human sign language processing. Handling variation in the precise execution of signs is an example of s...

  13. Two-Dimensional Automatic Measurement for Nozzle Flow Distribution Using Improved Ultrasonic Sensor

    OpenAIRE

    Changyuan Zhai; Chunjiang Zhao; Xiu Wang; Ning Wang; Wei Zou; Wei Li

    2015-01-01

    Spray deposition and distribution are affected by many factors, one of which is nozzle flow distribution. A two-dimensional automatic measurement system, which consisted of a conveying unit, a system control unit, an ultrasonic sensor, and a deposition collecting dish, was designed and developed. The system could precisely move an ultrasonic sensor above a pesticide deposition collecting dish to measure the nozzle flow distribution. A sensor sleeve with a PVC tube was designed for the ultras...

  14. AUTOMATIC EVOLUTION OF HEAT EXCHANGER NETWORKS WITH SIMULTANEOUS HEAT EXCHANGER DESIGN

    OpenAIRE

    F.S. LIPORACE; F.L.P. Pessoa; E.M. Queiroz

    1999-01-01

    Recently, a new software (AtHENS) that automatically synthesizes a heat exchanger network with minima consumption of utilities was developed. This work deals with the next step, which represents the evolution of the initial network. Hence, new procedures to identify and break loops are incorporated, for which a new algorithm is proposed. Also, a heat exchanger design procedure which uses the available pressure drop to determine the film coefficient on the tube side and shell side is added, pr...

  15. Multiobjective image recognition algorithm in the fully automatic die bonder

    Institute of Scientific and Technical Information of China (English)

    JIANG Kai; CHEN Hai-xia; YUAN Sen-miao

    2006-01-01

    It is a very important task to automatically fix the number of die in the image recognition system of a fully automatic die bonder.A multiobjective image recognition algorithm based on clustering Genetic Algorithm (GA),is proposed in this paper.In the evolutionary process of GA,a clustering method is provided that utilizes information from the template and the fitness landscape of the current population..The whole population is grouped into different niches by the clustering method.Experimental results demonstrated that the number of target images could be determined by the algorithm automatically,and multiple targets could be recognized at a time.As a result,time consumed by one image recognition is shortened,the performance of the image recognition system is improved,and the atomization of the system is fulfilled.

  16. Automatic sensor placement

    Science.gov (United States)

    Abidi, Besma R.

    1995-10-01

    Active sensing is the process of exploring the environment using multiple views of a scene captured by sensors from different points in space under different sensor settings. Applications of active sensing are numerous and can be found in the medical field (limb reconstruction), in archeology (bone mapping), in the movie and advertisement industry (computer simulation and graphics), in manufacturing (quality control), as well as in the environmental industry (mapping of nuclear dump sites). In this work, the focus is on the use of a single vision sensor (camera) to perform the volumetric modeling of an unknown object in an entirely autonomous fashion. The camera moves to acquire the necessary information in two ways: (a) viewing closely each local feature of interest using 2D data; and (b) acquiring global information about the environment via 3D sensor locations and orientations. A single object is presented to the camera and an initial arbitrary image is acquired. A 2D optimization process is developed. It brings the object in the field of view of the camera, normalizes it by centering the data in the image plane, aligns the principal axis with one of the camera's axes (arbitrarily chosen), and finally maximizes its resolution for better feature extraction. The enhanced image at each step is projected along the corresponding viewing direction. The new projection is intersected with previously obtained projections for volume reconstruction. During the global exploration of the scene, the current image as well as previous images are used to maximize the information in terms of shape irregularity as well as contrast variations. The scene on the borders of occlusion (contours) is modeled by an entropy-based objective functional. This functional is optimized to determine the best next view, which is recovered by computing the pose of the camera. A criterion based on the minimization of the difference between consecutive volume updates is set for termination of the

  17. Novel rotating field probe for inspection of tubes

    Science.gov (United States)

    Xin, J.; Tarkleson, E.; Lei, N.; Udpa, L.; Udpa, S. S.

    2012-05-01

    Inspection of steam generator tubes in nuclear power plants is extremely critical for safe operation of the power plant. In the nuclear industry, steam generator tube inspection using eddy current techniques has evolved over the years from a single bobbin coil, to rotating probe coil (RPC) and array probe, in an attempt to improve the speed and reliability of inspection. The RPC probe offers the accurate spatial resolution but involves complex mechanical rotation. This paper presents a novel design of eddy current probes based on rotating fields produced by three identical coils excited by a balanced three-phase supply. The sensor thereby achieves rotating probe functionality by electronic means and eliminates the need for mechanical rotation. The field generated by the probe is largely radial that result in induced currents that flow circularly around the radial axis and rotating around the tube at a synchronous speed effectively producing induced eddy currents that are multidirectional. The probe will consequently be sensitive to cracks of all orientations in the tube wall. The finite element model (FEM) results of the rotating fields and induced currents are presented. A prototype probe is being built to validate simulation results.

  18. Osmotic regulation of seamless tube growth.

    Science.gov (United States)

    Schottenfeld-Roames, Jodi; Ghabrial, Amin S

    2013-02-01

    Most organs are composed of tubes of differing cellular architectures, including intracellular 'seamless' tubes. Two studies examining the morphogenesis of the seamless tubes formed by the excretory canal cell in Caenorhabditis elegans reveal a previously unappreciated role for osmoregulation of tubulogenesis: hyperosmotic shock recruits canalicular vesicles to the lumenal membrane to promote seamless tube growth. PMID:23377027

  19. Osmotic regulation of seamless tube growth

    OpenAIRE

    Schottenfeld-Roames, Jodi; Ghabrial, Amin S.

    2013-01-01

    Most organs are composed of tubes of differing cellular architectures, including intracellular, “seamless” tubes. Two studies examining the morphogenesis of the C. elegans excretory canal cell seamless tubes reveal a previously unappreciated role for osmoregulation of tubulogenesis: hyperosmotic shock recruits canalicular vesicles to the lumenal membrane to promote seamless tube growth.

  20. [Folic acid: Primary prevention of neural tube defects. Literature Review].

    Science.gov (United States)

    Llamas Centeno, M J; Miguélez Lago, C

    2016-03-01

    Neural tube defects (NTD) are the most common congenital malformations of the nervous system, they have a multifactorial etiology, are caused by exposure to chemical, physical or biological toxic agents, factors deficiency, diabetes, obesity, hyperthermia, genetic alterations and unknown causes. Some of these factors are associated with malnutrition by interfering with the folic acid metabolic pathway, the vitamin responsible for neural tube closure. Its deficit produce anomalies that can cause abortions, stillbirths or newborn serious injuries that cause disability, impaired quality of life and require expensive treatments to try to alleviate in some way the alterations produced in the embryo. Folic acid deficiency is considered the ultimate cause of the production of neural tube defects, it is clear the reduction in the incidence of Espina Bifida after administration of folic acid before conception, this leads us to want to further study the action of folic acid and its application in the primary prevention of neural tube defects. More than 40 countries have made the fortification of flour with folate, achieving encouraging data of decrease in the prevalence of neural tube defects. This paper attempts to make a literature review, which clarify the current situation and future of the prevention of neural tube defects.

  1. Advances and Trends on Tube Bending Forming Technologies

    Institute of Scientific and Technical Information of China (English)

    YANG He; LI Heng; ZHANG Zhiyong; ZHAN Mei; LIU Jing; LI Guangjun

    2012-01-01

    As one kind of key components with enormous quantities and diversities,the bent tube parts satisfy the increasing needs for lightweight and high-strength product from both materials and structure aspects.The bent tubes have been widely used in many high-end industries such as aviation,aerospaee,shipbuilding,automobile,energy and health care.The tube bending has become one of the key manufacturing technologies for lightweight product forming.Via the analysis of bending characteristics and multiple defects,advances on exploring the common issues in tube bending are summarized regarding wrinkling instability at the intrados,wall thinning (cracking) at the extrados,springback phenomenon,cross-section deformation,forming limit and process/tooling design/optimization.Some currently developed bending techniques are reviewed in terms of their advantages and limitations.Finally,in view of the urgent requirements of high-performance complex bent tube components with difficult-to-deform and lightweight materials in aviation and aerospace fields,the development trends and corresponding challenges are presented for realizing the precise and high-efficiency tube bending deformation.

  2. MARZ: Manual and Automatic Redshifting Software

    CERN Document Server

    Hinton, Samuel R; Lidman, Chris; Glazebrook, Karl; Lewis, Geraint F

    2016-01-01

    The Australian Dark Energy Survey (OzDES) is a 100-night spectroscopic survey underway on the Anglo-Australian Telescope using the fibre-fed 2-degree-field (2dF) spectrograph. We have developed a new redshifting application Marz with greater usability, flexibility, and the capacity to analyse a wider range of object types than the Runz software package previously used for redshifting spectra from 2dF. Marz is an open-source, client-based, Javascript web-application which provides an intuitive interface and powerful automatic matching capabilities on spectra generated from the AAOmega spectrograph to produce high quality spectroscopic redshift measurements. The software can be run interactively or via the command line, and is easily adaptable to other instruments and pipelines if conforming to the current FITS file standard is not possible. Behind the scenes, a modified version of the Autoz cross-correlation algorithm is used to match input spectra against a variety of stellar and galaxy templates, and automat...

  3. Automatic transcription of Turkish microtonal music.

    Science.gov (United States)

    Benetos, Emmanouil; Holzapfel, André

    2015-10-01

    Automatic music transcription, a central topic in music signal analysis, is typically limited to equal-tempered music and evaluated on a quartertone tolerance level. A system is proposed to automatically transcribe microtonal and heterophonic music as applied to the makam music of Turkey. Specific traits of this music that deviate from properties targeted by current transcription tools are discussed, and a collection of instrumental and vocal recordings is compiled, along with aligned microtonal reference pitch annotations. An existing multi-pitch detection algorithm is adapted for transcribing music with 20 cent resolution, and a method for converting a multi-pitch heterophonic output into a single melodic line is proposed. Evaluation metrics for transcribing microtonal music are applied, which use various levels of tolerance for inaccuracies with respect to frequency and time. Results show that the system is able to transcribe microtonal instrumental music at 20 cent resolution with an F-measure of 56.7%, outperforming state-of-the-art methods for the same task. Case studies on transcribed recordings are provided, to demonstrate the shortcomings and the strengths of the proposed method. PMID:26520294

  4. Automatic Lumbar Spondylolisthesis Measurement in CT Images.

    Science.gov (United States)

    Liao, Shu; Zhan, Yiqiang; Dong, Zhongxing; Yan, Ruyi; Gong, Liyan; Zhou, Xiang Sean; Salganicoff, Marcos; Fei, Jun

    2016-07-01

    Lumbar spondylolisthesis is one of the most common spinal diseases. It is caused by the anterior shift of a lumbar vertebrae relative to subjacent vertebrae. In current clinical practices, staging of spondylolisthesis is often conducted in a qualitative way. Although meyerding grading opens the door to stage spondylolisthesis in a more quantitative way, it relies on the manual measurement, which is time consuming and irreproducible. Thus, an automatic measurement algorithm becomes desirable for spondylolisthesis diagnosis and staging. However, there are two challenges. 1) Accurate detection of the most anterior and posterior points on the superior and inferior surfaces of each lumbar vertebrae. Due to the small size of the vertebrae, slight errors of detection may lead to significant measurement errors, hence, wrong disease stages. 2) Automatic localize and label each lumbar vertebrae is required to provide the semantic meaning of the measurement. It is difficult since different lumbar vertebraes have high similarity of both shape and image appearance. To resolve these challenges, a new auto measurement framework is proposed with two major contributions: First, a learning based spine labeling method that integrates both the image appearance and spine geometry information is designed to detect lumbar vertebrae. Second, a hierarchical method using both the population information from atlases and domain-specific information in the target image is proposed for most anterior and posterior points positioning. Validated on 258 CT spondylolisthesis patients, our method shows very similar results to manual measurements by radiologists and significantly increases the measurement efficiency. PMID:26849859

  5. Pump element for a tube pump

    DEFF Research Database (Denmark)

    2011-01-01

    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...... pump as mentioned above, thereby acting to generate a fluid flow through the tube upon repeated deformation of the tube between the two valve members. The pump element may comprise a connecting part for coupling to another tube and may comprise a sealing part establishing a fluid tight connection...

  6. RendezVous sensor for automatic guidance of transfer vehicles to the International Space Station

    Science.gov (United States)

    Kolk, Karl-Hermann; Moebius, Bettina G.

    2000-10-01

    Based on a Predevelopment Program, initiated by the European Space Agency, an automatically operating RendezVous Sensor (RVS) is currently developed. This paper describes in more detail the RVS concept emphasizing the electro-optical elements of the sensor.

  7. 49 CFR 230.61 - Arch tubes, water bar tubes, circulators and thermic siphons.

    Science.gov (United States)

    2010-10-01

    ... MAINTENANCE STANDARDS Boilers and Appurtenances Washing Boilers § 230.61 Arch tubes, water bar tubes, circulators and thermic siphons. (a) Frequency of cleaning. Each time the boiler is washed, arch tubes and... 49 Transportation 4 2010-10-01 2010-10-01 false Arch tubes, water bar tubes, circulators...

  8. An Automatic Proof of Euler's Formula

    Directory of Open Access Journals (Sweden)

    Jun Zhang

    2005-05-01

    Full Text Available In this information age, everything is digitalized. The encoding of functions and the automatic proof of functions are important. This paper will discuss the automatic calculation for Taylor expansion coefficients, as an example, it can be applied to prove Euler's formula automatically.

  9. Self-Compassion and Automatic Thoughts

    Science.gov (United States)

    Akin, Ahmet

    2012-01-01

    The aim of this research is to examine the relationships between self-compassion and automatic thoughts. Participants were 299 university students. In this study, the Self-compassion Scale and the Automatic Thoughts Questionnaire were used. The relationships between self-compassion and automatic thoughts were examined using correlation analysis…

  10. Inspection and non destructive testing of tube joints in a titanium condenser

    International Nuclear Information System (INIS)

    The condensers includes 3 separate units, each containing 14,300 tubes. Various construction materials were applied. The tube plates were made of 34 mm thick carbon steel explosively clad with a 6 mm Ti sheet. The tubes were seam-welded Ti strip. Support plates, shell and water boxes were made of plain carbon steel. Tube testing is carried out both at the tube production plant and on delivery prior to assembly using Eddy-current testing, ultrasonic testing, air-leak and helium-leak testing. The seal-weld test system includes microfocus radiography, Eddy-current testing, weld parameter monitoring. The Eddy-current seal-weld system is described and the results obtained given

  11. Nervous system examination on YouTube

    Directory of Open Access Journals (Sweden)

    Azer Samy A

    2012-12-01

    Full Text Available Abstract Background Web 2.0 sites such as YouTube have become a useful resource for knowledge and are used by medical students as a learning resource. This study aimed at assessing videos covering the nervous system examination on YouTube. Methods A research of YouTube was conducted from 2 November to 2 December 2011 using the following key words “nervous system examination”, “nervous system clinical examination”, “cranial nerves examination”, “CNS examination”, “examination of cerebellum”, “balance and coordination examination”. Only relevant videos in the English language were identified and related URL recorded. For each video, the following information was collected: title, author/s, duration, number of viewers, number of posted comments, and total number of days on YouTube. Using criteria comprising content, technical authority and pedagogy parameters, videos were rated independently by three assessors and grouped into educationally useful and non-educationally useful. Results A total of 2240 videos were screened; 129 were found to have relevant information to nervous system examination. Analysis revealed that 61 (47% of the videos provided useful information on the nervous system examination. These videos scored (mean ± SD, 14.9 ± 0.2 and mainly covered examination of the whole nervous system (8 videos, 13%, cranial nerves (42 videos, 69%, upper limbs (6 videos, 10%, lower limbs (3 videos, 5%, balance and co-ordination (2 videos, 3%. The other 68 (53% videos were not useful educationally; scoring (mean ± SD, 11.1 ± 3.0. The total viewers of all videos was 2,189,434. Useful videos were viewed by 1,050,445 viewers (48% of total viewers. The total viewership per day for useful videos was 1,794.5 and for non-useful videos 1,132.0. The differences between the three assessors were insignificant (less than 0.5 for the mean and 0.3 for the SD. Conclusions Currently, YouTube provides an adequate resource

  12. Analysis of the State of Steam Generator Tubes

    Energy Technology Data Exchange (ETDEWEB)

    Bergunker, Olga [JSC OKB ' Gidropress' , 142103 Podolsk (Russian Federation)

    2008-07-01

    The problem of safe operation of SG heat exchanging tubes, of both economical and effective control of their state is still important these days. Issues connected with peculiarities of methods of SG tubes inspection, automated analysis of the inspection results, tubes state analysis and development of algorithms of forecasting their state are considered in this report. The need for effective use of extensive data arrays on SG operation has led to the necessity of creating software tools for collection, storage and analysis of these data. The data-analytical system 'NPP Steam Generators' meant for data systematization and visualization as well as various types of analyses of data on eddy current inspection of WWER-440 and WWER-1000 SG tubes is presented in this report. The main possibilities of the data-analytical system (DAS), the code current state and prospects of its development are shown. The main fields of DAS application are considered and some results of its practical use are mentioned, namely, in the field of forecasting SG tubes state. (authors)

  13. The tube current modulation base on time bolus peak in low voltage:a clinical study%循环测试峰值调制管电流在低管电压CTPA 中的临床应用

    Institute of Scientific and Technical Information of China (English)

    赵磊; 包丽丽; 王泽锋; 刘挨师

    2015-01-01

    Objective To evaluate the image quality and obtained by the tube current modulation base on time bolus peak in low voltage in CTPA.Methods 30 consecutive patients suspected pulmonary embolism(PE)were prospectively enrolled,and satisfy the following conditions.The study was performed by 64-slice spiral CT system (lightspeed VCT-XT,GE healthcare),Tube voltage was set at 80 kV.Tube current settings related to the attenuation of ROIs by test bolus peak.The injection parameters were set up by injection flow rate (4 mL/s),contrast medium dose (28 mL),and saline flushing dose (40 mL).All images were evaluated by two observers blinded to pulmonary CTA protocol,including attenuation,noise,SNR and CNR.The image quality was evaluate by 4-score.To evaluate the relationship between influential factor and image quality using Pearson correlation analysis.A P-value 0.05 ).The mean attenuation,noise,SNR and CNR on pulmonary trunk was (628.63±146.46)HU,(53.92±14.07)HU,12.02±3.1 7 and 10.81±3.10,respectively.The percentage of assessable pulmonary arteries was 95.82%.Conclusion The tube current modulation base on time bolus peak in low voltage could offer assessable image quality and raise image stability.%目的:评价 CTPA 低管电压下通过循环测试峰值调制管电流的图像质量。方法连续选取满足纳入标准与排除标准的可疑肺动脉栓塞患者30例。采用64层螺旋 CT 系统,管电压设置为80 kV,管电流根据循环时间测试感兴趣区衰减值进行设置。注射流率为4 mL/s,对比剂剂量为28 mL、盐水冲洗剂量为40 mL。由2位观察者在不知道扫描参数的情况下对肺动脉干层面管腔衰减值、噪声值、信噪比(SNR)与对比噪声比(CNR)进行测量,并以4分制(4分优,1分差)进行评价。对影响因素与图像质量进行相关性分析。P<0.05认为差异具有统计学意义。结果 Pearson 相关分析显示循环时间测试峰值与衰减值呈正相关(r=0.398, P=0.029),循环时间

  14. Laser initiated endotracheal tube explosion.

    Science.gov (United States)

    De Vane, G G

    1990-06-01

    A 62-year-old male with a diagnosis of subglottic and tracheal stenosis resulting from a prolonged intubation was scheduled for a laser bronchoscopy and placement of a silicon T-shaped tube. His history was significant for two myocardial infarctions, an episode of congestive heart failure and exertional angina. A 6 mm polyvinyl chloride endotracheal tube, wrapped with aluminum tape, was placed in an existing tracheostomy stoma. During the course of the procedure, a sudden bright flash occurred followed by an explosive noise and black smoke rising in the anesthesia circuit and from the patient's mouth. The endotracheal tube was removed and the patient was treated for first and second degree burns in the supraglottic area and base of the tongue. In laser surgery of the airway, special care should be given to reducing the flammability of the inspired gases which can be best accomplished by the mixture of helium with oxygen. Helium acts to retard ignition of polyvinyl chloride tubes in concentrations of 60% or greater. The external surface of the tube can also be protected with the application of a metallic tape affixed in a spiral fashion. Finally, a protocol for the management and treatment of this emergency should be adopted and rehearsed. PMID:2378234

  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. Analysis of autofrettaged metal tubes

    International Nuclear Information System (INIS)

    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)

  17. Repair technology for steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung Ho; Jung, Hyun Kyu; Jung, Seung Ho; Kim, Chang Hoi; Jung, Young Moo; Seo, Yong Chil; Kim, Jung Su; Seo, Moo Hong

    2001-02-01

    The most commonly used sleeving materials are thermally treated Alloy 600 and thermally treated Alloy 690 Alloy. Currently, thermally treated Alloy 690 and Alloy 800 are being offered although Alloy 800 has not been licensed in the US. To install sleeve, joint strength, leak tightness, PWSCC resistance, evaluation on process parameter range and the effect of equipments and procedures on repair plan and radiation damage have to be investigated before sleeving. ABB CE provides three type of leak tight Alloy 690 TIG welded and PLUSS sleeve. Currently, Direct Tube Repair technique using Nd:YAG laser has been developed by ABB CE and Westinghouse. FTI has brazed and kinetic sleeve designs for recirculating steam generator and hydraulic and rolled sleeve designs for one-through steam generators. Westinghouse provides HEJ, brazed and laser welded sleeve design. When sleeve is installed in order to repair the damaged S/G tubes, it is certain that defects can be occurred due to the plastic induced stress and thermal stress. Therefore it is important to minimize the residual stress. FTI provides the electrosleeve technique as a future repair candidate using electroplating.

  18. Repair technology for steam generator tubes

    International Nuclear Information System (INIS)

    The most commonly used sleeving materials are thermally treated Alloy 600 and thermally treated Alloy 690 Alloy. Currently, thermally treated Alloy 690 and Alloy 800 are being offered although Alloy 800 has not been licensed in the US. To install sleeve, joint strength, leak tightness, PWSCC resistance, evaluation on process parameter range and the effect of equipments and procedures on repair plan and radiation damage have to be investigated before sleeving. ABB CE provides three type of leak tight Alloy 690 TIG welded and PLUSS sleeve. Currently, Direct Tube Repair technique using Nd:YAG laser has been developed by ABB CE and Westinghouse. FTI has brazed and kinetic sleeve designs for recirculating steam generator and hydraulic and rolled sleeve designs for one-through steam generators. Westinghouse provides HEJ, brazed and laser welded sleeve design. When sleeve is installed in order to repair the damaged S/G tubes, it is certain that defects can be occurred due to the plastic induced stress and thermal stress. Therefore it is important to minimize the residual stress. FTI provides the electrosleeve technique as a future repair candidate using electroplating

  19. Knowledge-based full-automatic control system for a nuclear ship reactor

    International Nuclear Information System (INIS)

    Plant operations aboard nuclear ships require quick judgements and actions due to changing marine conditions such as wind, waves and currents. Furthermore, additional human support is not available for nuclear ship operation at sea, so advanced automatic operations are necessary to reduce the number of operators required finally. Therefore, an advanced automatic operating system has been developed based on operational knowledge of nuclear ship 'Mutsu' plant. The advanced automatic operating system includes both the automatic operation system and the operator-support system which assists operators in completing actions during plant accidents, anomaly diagnosis and plant supervision. These system are largely being developed using artificial intelligent techniques such as neural network, fuzzy logic and knowledge-based expert. The automatic operation system is fundamentally based upon application of an operator's knowledge of both normal (start-up to rated power level) and abnormal (after scram) operations. Comparing plant behaviors from start-up to power level by the automatic operation with by 'Mutsu' manual operation, stable automatic operation was obtained almost same as manual operation within all operating limits. The abnormal automatic system was for hard work of manual operations after scram or LOCA accidents. An integrating system with the normal and the abnormal automatic systems are being developed for interacting smoothly both systems. (author)

  20. Knowledge-based full-automatic control system for a nuclear ship reactor

    Energy Technology Data Exchange (ETDEWEB)

    Shimazaki, J.; Nakazawa, T.; Yabuuchi, N. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan)

    2000-03-01

    Plant operations aboard nuclear ships require quick judgements and actions due to changing marine conditions such as wind, waves and currents. Furthermore, additional human support is not available for nuclear ship operation at sea, so advanced automatic operations are necessary to reduce the number of operators required finally. Therefore, an advanced automatic operating system has been developed based on operational knowledge of nuclear ship 'Mutsu' plant. The advanced automatic operating system includes both the automatic operation system and the operator-support system which assists operators in completing actions during plant accidents, anomaly diagnosis and plant supervision. These system are largely being developed using artificial intelligent techniques such as neural network, fuzzy logic and knowledge-based expert. The automatic operation system is fundamentally based upon application of an operator's knowledge of both normal (start-up to rated power level) and abnormal (after scram) operations. Comparing plant behaviors from start-up to power level by the automatic operation with by 'Mutsu' manual operation, stable automatic operation was obtained almost same as manual operation within all operating limits. The abnormal automatic system was for hard work of manual operations after scram or LOCA accidents. An integrating system with the normal and the abnormal automatic systems are being developed for interacting smoothly both systems. (author)