WorldWideScience

Sample records for pitot tubes

  1. Diagnosis of UAV Pitot Tube Defects Using Statistical Change Detection

    DEFF Research Database (Denmark)

    Hansen, Søren; Blanke, Mogens; Adrian, Jens

    2010-01-01

    Unmanned Aerial Vehicles need a large degree of tolerance to faults. One of the most important steps towards this is the ability to detect and isolate faults in sensors and actuators in real time and make remedial actions to avoid that faults develop to failure. This paper analyses...... the possibilities of detecting faults in the pitot tube of a small unmanned aerial vehicle, a fault that easily causes a crash if not diagnosed and handled in time. Using as redundant information the velocity measured from an onboard GPS receiver, the air-speed estimated from engine throttle and the pitot tube...

  2. State-of-the-Art Report on Five-hole Pitot tube

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Hyuk; Hwang, D. H.; Seo, K. W

    2007-03-15

    Five-hole pitot tube is an effective detector that could measure a three dimensional average flow field on a complex geometry. At the present study, have been mainly used in the field of aerodynamics and nautics, the five-hole pitot tube is extensively investigated to apply on the nuclear engineering. Five-hole pitot tube could measure the three dimensional velocity to make use of a relationship between pressure energy and kinetic energy from Bernoulli's equation; therefore, the report shortly overviewed the definition, units, and transducers of pressure and then detaily was described about the pitot tube. For five-hole pitot tube, history, kinds and fabrication methods were briefly provided. The calibration methods for the five-hole pitot tube were deeply introduced in various methods according to simple concept but complex process. Additionally, causeses of detection errors and estimation of uncertainty were included in the present report. Optical measurement and how wire anemometers are difficult to detect the flow velocity under environmental such as tight lattice bundle geometry, dusty flow and high temperature fluid. One of alternatives to overcome the diffculty is the five-hole pitot tube.

  3. Multi-gate Pitot tube for the measurement of water flow in cooling systems; Tubo de Pitot multi-puertos para la medicion de flujo de agua en sistemas de enfriamiento

    Energy Technology Data Exchange (ETDEWEB)

    Figueroa Ibarra, Luis; Rodriguez Martinez, Jose Hugo; Santabarbara Botello, Marcelino [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2007-07-01

    In this article the design of a novel measuring device of water flowing in large diameter pipes is described. A description is made of the instrument commonly used at present for this purpose (simple Pitot tube), whose design is based on the Standard CTI Code ATC-105 published by the Cooling Tower Institute (CTI ATC-105, 2000). The disadvantages of the simple Pitot tube in comparison with the new proposed device are emphasized (Multi-gate Pitot tube), of which its construction and design is described in detail. In the present article are also shown the results obtained of the circulation water flow measurements, performed in the cooling system of a fossil fuel power plant. These results are compared with the results of flow measurement obtained by means of the simulation of the thermodynamic cycle of the power station, using commercial software. [Spanish] En este articulo se describe el diseno de un novedoso medidor de flujo de agua que circula en tuberias de gran diametro. Se hace una descripcion del instrumento comunmente usado en la actualidad para dicho proposito (tubo de Pitot simple), cuyo diseno se basa en el estandar CTI Code ATC-105 publicado por el Cooling Tower Institute (CTI ATC-105, 2000). Se puntualizan las desventajas del tubo de Pitot simple en comparacion con el nuevo dispositivo propuesto (tubo de Pitot Multi-puertos), del cual se describe detalladamente su construccion y diseno. En el presente articulo tambien se muestran los resultados obtenidos de las mediciones de flujo de agua de circulacion, realizadas en el sistema de enfriamiento de una central termoelectrica. Dichos resultados son comparados con los resultados de flujo obtenidos mediante simulacion del ciclo termodinamico de la central, usando un software comercial.

  4. Concept of a Pitot tube able to detect blockage by ice, volcanic ash, sand and insects, and to clear the tube

    Science.gov (United States)

    Jackson, David A.

    2015-12-01

    A conceptual coaxial Pitot tube (PT) has been developed using fiber optic sensors combined with actuators to monitor and maintain its correct operation under different environmental conditions. Experiments were performed showing that the dynamic and static tubes can be cleared of ice. It was also demonstrated that the dynamic tube could be cleared of dust and sand which was not the case for the static tube in the coaxial configuration. An approach was proposed to overcome this problem involving a conventional configuration where the static tube was operated independently orthogonal to the dynamic tube, and a second set of sensors and actuators was used. Sensors and associated actuators were developed for temperature and intensity for a linear PT. The aim of this work is to propose a solution for a problem that has caused the loss of the lives of many passengers and crew of aircraft. Resources were not available to test a full implementation of a PT incorporating the proposed modifications.

  5. Turbulent wind field characterization and re-generation based on pitot tube measurements mounted on a wind turbine

    DEFF Research Database (Denmark)

    Pedersen, Mads Mølgaard; Larsen, Torben J.; Aagaard Madsen, Helge;

    2015-01-01

    This paper describes a new method to estimate the undisturbed inflow field of a wind turbine based on measurements obtained from one or more five-hole pitot tubes mounted directly on the blades. Based on the measurements, the disturbance caused by the wind turbine is estimated using aerodymanic...... the measured wind speeds at the recording position. In the theoretical part of this study a quite good agreement is seen between load sensors on a turbine model exposed to the reference and the re-generated turbulence field. Finally the method is applied to full scale measurements and reasonable wind shear...... profiles are derived. It is expected that this method will lead to a new and effective experimental method to characterize the incoming flow field to a wind turbine and thus contribute to the understanding of wind turbine loads....

  6. Micro manometer and pitot tube for measuring the velocity distribution in a natural convection water stream between two vertical parallel plates (1961); Micromano metre et tube de pitot destines a l'exploration du profil de vitesse dans un ecoulement d'eau de convection naturelle entre deux plaques verticales paralleles (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Santon, L.; Vernier, Ph. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1961-07-01

    For heat transfer studies in certain cases of cooling in swimming-pool type nuclear reactors, a knowledge of the distribution of the velocities between two heating elements is of prime importance. A Pitot tube and a micro-manometer have been developed for making these measurements on an experimental model. (authors) [French] Pour l'etude du transfert de chaleur dans certains cas de refroidissement des reacteurs nucleaires du type piscine, la connaissance de la repartition des vitesses entre deux elements chauffants est primordiale. On a mis au point un tube de Pitot et un micromanometre pour effectuer ces mesures sur une maquette experimentale. (auteurs)

  7. Are estimates of wind characteristics based on measurements with Pitot tubes and GNSS receivers mounted on consumer-grade unmanned aerial vehicles applicable in meteorological studies?

    Science.gov (United States)

    Niedzielski, Tomasz; Skjøth, Carsten; Werner, Małgorzata; Spallek, Waldemar; Witek, Matylda; Sawiński, Tymoteusz; Drzeniecka-Osiadacz, Anetta; Korzystka-Muskała, Magdalena; Muskała, Piotr; Modzel, Piotr; Guzikowski, Jakub; Kryza, Maciej

    2017-09-01

    The objective of this paper is to empirically show that estimates of wind speed and wind direction based on measurements carried out using the Pitot tubes and GNSS receivers, mounted on consumer-grade unmanned aerial vehicles (UAVs), may accurately approximate true wind parameters. The motivation for the study is that a growing number of commercial and scientific UAV operations may soon become a new source of data on wind speed and wind direction, with unprecedented spatial and temporal resolution. The feasibility study was carried out within an isolated mountain meadow of Polana Izerska located in the Izera Mountains (SW Poland) during an experiment which aimed to compare wind characteristics measured by several instruments: three UAVs (swinglet CAM, eBee, Maja) equipped with the Pitot tubes and GNSS receivers, wind speed and direction meters mounted at 2.5 and 10 m (mast), conventional weather station and vertical sodar. The three UAVs performed seven missions along spiral-like trajectories, most reaching 130 m above take-off location. The estimates of wind speed and wind direction were found to agree between UAVs. The time series of wind speed measured at 10 m were extrapolated to flight altitudes recorded at a given time so that a comparison was made feasible. It was found that the wind speed estimates provided by the UAVs on a basis of the Pitot tube/GNSS data are in agreement with measurements carried out using dedicated meteorological instruments. The discrepancies were recorded in the first and last phases of UAV flights.

  8. Improving Accuracy of Averaging Pitot Tube Flow Sensor at Downstream of Elbow%提高弯头下游均速管流量传感器测量精度的研究

    Institute of Scientific and Technical Information of China (English)

    孙立军; 孙超; 邱香

    2014-01-01

    当均速管流量传感器安装在弯头下游时,由于流体流动为非充分发展湍流,会增大其流量测量的误差.为提高流量测量精度,提出了在90°弯头下游安装流动调整器改善速度分布对称性,减小测量误差的方法.采用计算流体力学(CFD)仿真分析与实流实验相结合的方法,基于 NEL 流动调整器,设计出了改进型的流动调整器结构.经仿真和实验验证,安装改进的流动调整器后,均速管流量传感器的线性度误差减小到了0.176%.流动机理分析发现,上游流体速度剖面对称性是影响传感器误差的关键因素.数据表明,CFD仿真预测线性度误差的偏差小于0.056%.%When the averaging Pitot tube flow sensor is installed at the downstream of elbow,the flow regime is not fully-developed turbulence,which will increase the error of flow measurement. In order to improve the accuracy of flow meas-urement,a method to reduce the error by installing a flow conditioner at the downstream of the 90°elbow for reforming the symmetry of flow velocity profile was put forward. Based on the NEL flow conditioner,the improved flow conditioner was designed by the method of computational fluid dynamics(CFD)simulation and analysis combined with real flow experiment. Verified by the simulation and experiment,after installing the improved flow conditioner,the linearity error of the averag-ing Pitot tube flow sensor was decreased to 0.176%. It has been found through analyzing the flow mechanism that the sym-metry of the velocity profile at the upstream of the flow sensor is the main factor affecting the error of the sensor. It is indi-cated in the data that the difference of the linearity error predicted by the CFD simulation is less than 0.056%.

  9. 14 CFR 25.1326 - Pitot heat indication systems.

    Science.gov (United States)

    2010-01-01

    ....1326 Pitot heat indication systems. If a flight instrument pitot heating system is installed, an indication system must be provided to indicate to the flight crew when that pitot heating system is not... pitot heating system is switched “off”. (2) The pitot heating system is switched “on” and any pitot...

  10. In-Flight Pitot-Static Calibration

    Science.gov (United States)

    Foster, John V. (Inventor); Cunningham, Kevin (Inventor)

    2016-01-01

    A GPS-based pitot-static calibration system uses global output-error optimization. High data rate measurements of static and total pressure, ambient air conditions, and GPS-based ground speed measurements are used to compute pitot-static pressure errors over a range of airspeed. System identification methods rapidly compute optimal pressure error models with defined confidence intervals.

  11. 14 CFR 23.1326 - Pitot heat indication systems.

    Science.gov (United States)

    2010-01-01

    ... Instruments: Installation § 23.1326 Pitot heat indication systems. If a flight instrument pitot heating system... provided to indicate to the flight crew when that pitot heating system is not operating. The indication... alert the flight crew if either of the following conditions exist: (1) The pitot heating system...

  12. 14 CFR 125.206 - Pitot heat indication systems.

    Science.gov (United States)

    2010-01-01

    ... flight instrument pitot heating system unless the airplane is equipped with an operable pitot heat... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Pitot heat indication systems. 125.206... Equipment Requirements § 125.206 Pitot heat indication systems. (a) Except as provided in paragraph (b)...

  13. 14 CFR 135.158 - Pitot heat indication systems.

    Science.gov (United States)

    2010-01-01

    ... instrument pitot heating system unless the airplane is also equipped with an operable pitot heat indication... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Pitot heat indication systems. 135.158... Equipment § 135.158 Pitot heat indication systems. (a) Except as provided in paragraph (b) of this...

  14. 14 CFR 121.342 - Pitot heat indication systems.

    Science.gov (United States)

    2010-01-01

    ... a flight instrument pitot heating system unless the airplane is also equipped with an operable pitot... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Pitot heat indication systems. 121.342... heat indication systems. No person may operate a transport category airplane or, after December...

  15. Experimental study on a simple Ranque Hilsch vortex tube

    Science.gov (United States)

    Gao, C. M.; Bosschaart, K. J.; Zeegers, J. C. H.; de Waele, A. T. A. M.

    2005-03-01

    The Ranque-Hilsch vortex tube is a device by which cold gas can be generated using compressed gas. To understand the cooling mechanism of this device, it is necessary to know the pressure, temperature, and velocity distributions inside the tube. In order to investigate this, a simple vortex tube is built and nitrogen is used as its working fluid. A special Pitot tube is used for the measurement of the pressure and velocity. This Pitot tube consists of a capillary which has only one hole in the cylinder wall. With this Pitot tube, the pressure and velocity fields inside the tube were measured. In the same way, the temperature field was measured with a thermocouple. The results of three different entrance conditions are compared here. With the measurements results, the analysis based on the two thermodynamic laws has been made. It is found that rounding off the entrance has influence on the performance of the vortex tube. The secondary circulation gas flow inside the vortex tube can be enhanced and enlarged, the performance of the Ranque-Hilsch vortex tube improved.

  16. In-Flight and Pre-Flight Detection of Pitot Tube Anomalies Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The health and integrity of aircraft sensors and instruments play a critical role in aviation safety. However, inaccurate or false readings from these same...

  17. In-Flight and Pre-Flight Detection of Pitot Tube Anomalies Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The health and integrity of aircraft sensors play a critical role in aviation safety. Unfortunately, inaccurate or false readings from these sensors can lead to...

  18. Acoustic waves in shock tunnels and expansion tubes

    Science.gov (United States)

    Paull, A.; Stalker, R. J.

    1992-01-01

    It is shown that disturbances in shock and expansion tubes can be modelled as lateral acoustic waves. The ratio of sound speed across the driver-test gas interface is shown to govern the quantity of noise in the test gas. Frequency 'focusing' which is fundamental to centered unsteady expansions is discussed and displayed in centerline pitot pressure measurements.

  19. A GPS-Based Pitot-Static Calibration Method Using Global Output-Error Optimization

    Science.gov (United States)

    Foster, John V.; Cunningham, Kevin

    2010-01-01

    Pressure-based airspeed and altitude measurements for aircraft typically require calibration of the installed system to account for pressure sensing errors such as those due to local flow field effects. In some cases, calibration is used to meet requirements such as those specified in Federal Aviation Regulation Part 25. Several methods are used for in-flight pitot-static calibration including tower fly-by, pacer aircraft, and trailing cone methods. In the 1990 s, the introduction of satellite-based positioning systems to the civilian market enabled new inflight calibration methods based on accurate ground speed measurements provided by Global Positioning Systems (GPS). Use of GPS for airspeed calibration has many advantages such as accuracy, ease of portability (e.g. hand-held) and the flexibility of operating in airspace without the limitations of test range boundaries or ground telemetry support. The current research was motivated by the need for a rapid and statistically accurate method for in-flight calibration of pitot-static systems for remotely piloted, dynamically-scaled research aircraft. Current calibration methods were deemed not practical for this application because of confined test range size and limited flight time available for each sortie. A method was developed that uses high data rate measurements of static and total pressure, and GPSbased ground speed measurements to compute the pressure errors over a range of airspeed. The novel application of this approach is the use of system identification methods that rapidly compute optimal pressure error models with defined confidence intervals in nearreal time. This method has been demonstrated in flight tests and has shown 2- bounds of approximately 0.2 kts with an order of magnitude reduction in test time over other methods. As part of this experiment, a unique database of wind measurements was acquired concurrently with the flight experiments, for the purpose of experimental validation of the

  20. Laser transit anemometer and Pitot probe comparative measurements in a sharp cone boundary layer at Mach 4

    Science.gov (United States)

    Hunter, W. W., Jr.; Ocheltree, S. L.; Russ, C. E., Jr.

    1991-01-01

    Laser transit anemometer (LTA) measurements of a 7 degree sharp cone boundary layer were conducted in the Air Force/AEDC Supersonic Tunnel A Mach 4 flow field. These measurements are compared with Pitot probe measurements and tricone theory provided by AEDC staff. Measurements were made both in laminar and turbulent boundary layers of the model. Comparison of LTA measurements with theory showed agreement to better than 1 percent for the laminar boundary layer cases. This level of agreement was obtained after small position corrections, 0.01 to 0.6 mm, were applied to the experimental data sets. Pitot probe data when compared with theory also showed small positioning errors. The Pitot data value was also limited due to probe interference with the flow near the model. The LTA turbulent boundary layer data indicated a power law dependence of 6.3 to 6.9. The LTA data was analyzed in the time (Tau) domain in which it was obtained and in the velocity domain. No significant differences were noted between Tau and velocity domain results except in one turbulent boundary layer case.

  1. Ear Tubes

    Science.gov (United States)

    ... ENTCareers Marketplace Find an ENT Doctor Near You Ear Tubes Ear Tubes Patient Health Information News media ... and throat specialist) may be considered. What are ear tubes? Ear tubes are tiny cylinders placed through ...

  2. Tracheostomy tubes.

    Science.gov (United States)

    Hess, Dean R; Altobelli, Neila P

    2014-06-01

    Tracheostomy tubes are used to administer positive-pressure ventilation, to provide a patent airway, and to provide access to the lower respiratory tract for airway clearance. They are available in a variety of sizes and styles from several manufacturers. The dimensions of tracheostomy tubes are given by their inner diameter, outer diameter, length, and curvature. Differences in dimensions between tubes with the same inner diameter from different manufacturers are not commonly appreciated but may have important clinical implications. Tracheostomy tubes can be cuffed or uncuffed and may be fenestrated. Some tracheostomy tubes are designed with an inner cannula. It is important for clinicians caring for patients with a tracheostomy tube to appreciate the nuances of various tracheostomy tube designs and to select a tube that appropriately fits the patient. The optimal frequency of changing a chronic tracheostomy tube is controversial. Specialized teams may be useful in managing patients with a tracheostomy. Speech can be facilitated with a speaking valve in patients with a tracheostomy tube who are breathing spontaneously. In mechanically ventilated patients with a tracheostomy, a talking tracheostomy tube, a deflated cuff technique with a speaking valve, or a deflated cuff technique without a speaking valve can be used to facilitate speech. Copyright © 2014 by Daedalus Enterprises.

  3. Efficient Algorithm for a k-out-of-N System Reliability Modeling-Case Study: Pitot Sensors System for Aircraft Velocity

    Directory of Open Access Journals (Sweden)

    Wajih Ezzeddine

    2017-08-01

    Full Text Available The k-out-of-N system is widely applied in several industrial systems. This structure is a part of fault-tolerant systems for which both parallel and series systems are special cases. Because of the importance of industrial systems reliability determination for production and maintenance management purposes, a number of techniques and methods are incorporated to formulate and estimate its analytic expression. In this paper, an algorithm is put forward for a k-out-of-N system with identical components under information about the influence factors that affect the system efficiency. The developed approach is applied in the case of the Pitot sensors system. However, the algorithm application could be generalized for any device which during a mission is subject to environmental and operational factors that affect its degradation process.

  4. Gastrostomy Tube (G-Tube)

    Science.gov (United States)

    ... the recovery room, sometimes called the "post-op" (post-operative) room or PACU (post-anesthesia care unit), and ... site; discharge that's yellow, green, or foul-smelling; fever) excessive bleeding or drainage from the tube site ...

  5. Chest tube insertion

    Science.gov (United States)

    ... tube insertion; Insertion of tube into chest; Tube thoracostomy; Pericardial drain ... Kirsch TD, Sax J. Tube thoracostomy. In: Roberts JR, ed. Roberts and ... . 6th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 10.

  6. Jejunostomy feeding tube

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000181.htm Jejunostomy feeding tube To use the sharing features on this ... vomiting Your child's stomach is bloated Alternate Names Feeding - jejunostomy tube; G-J tube; J-tube; Jejunum ...

  7. 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.

  8. 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.

  9. 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.

  10. Feeding tube - infants

    Science.gov (United States)

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

  11. Tube-shape verifier

    Science.gov (United States)

    Anderson, A. N.; Christ, C. R.

    1980-01-01

    Inexpensive apparatus checks accuracy of bent tubes. Assortment of slotted angles and clamps is bolted down to flat aluminum plate outlining shape of standard tube bent to desired configuration. Newly bent tubes are then checked against this outline. Because parts are bolted down, tubes can be checked very rapidly without disturbing outline. One verifier per tube-bending machine can really speed up production in tube-bending shop.

  12. Feeding tube insertion - gastrostomy

    Science.gov (United States)

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

  13. 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 ...

  14. Intercostal drainage tube or intracardiac drainage tube?

    Directory of Open Access Journals (Sweden)

    N Anitha

    2016-01-01

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

  15. Pulse Tube Refrigerator

    Science.gov (United States)

    Matsubara, Yoichi

    The pulse tube refrigerator is one of the regenerative cycle refrigerators such as Stirling cycle or Gifford-McMahon cycle which gives the cooling temperature below 150 K down to liquid helium temperature. In 1963, W. E. Gifford invented a simple refrigeration cycle which is composed of compressor, regenerator and simple tube named as pulse tube which gives a similar function of the expander in Stirling or Gifford-McMahon cycle. The thermodynamically performance of this pulse tube refrigerator is inferior to that of other regenerative cycles. In 1984, however, Mikulin and coworkers made a significant advance in pulse tube configuration called as orifice pulse tube. After this, several modifications of the pulse tube hot end configuration have been developed. With those modifications, the thermodynamic performance of the pulse tube refrigerator became the same order to that of Stirling and Gifford-McMahon refrigerator. This article reviews the brief history of the pulse tube refrigerator development in the view point of its thermodynamically efficiency. Simplified theories of the energy flow in the pulse tube have also been described.

  16. Analysis of the Effect of Geomagnetic Declination on Wind Measurement by UAV with Pitot-static Tube%磁偏角对无人机皮托-静压管测风的影响分析

    Institute of Scientific and Technical Information of China (English)

    周伟静; 沈怀荣

    2006-01-01

    从无人机(unmanned aerial vehicle, UAV)皮托-静压管测风对磁偏角的敏感性出发,借助无人机皮托-静压管测风原理和误差理论,建立了磁偏角对测风影响的风速误差数学模型;通过仿真,分析了磁偏角对风速测量的影响和误差变化规律,并通过试验数据验证了仿真结论,为磁偏角的校正,提高风速测量精度提供了参考依据.

  17. Heated Tube Facility

    Data.gov (United States)

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

  18. Fuel nozzle tube retention

    Energy Technology Data Exchange (ETDEWEB)

    Cihlar, David William; Melton, Patrick Benedict

    2017-02-28

    A system for retaining a fuel nozzle premix tube includes a retention plate and a premix tube which extends downstream from an outlet of a premix passage defined along an aft side of a fuel plenum body. The premix tube includes an inlet end and a spring support feature which is disposed proximate to the inlet end. The premix tube extends through the retention plate. The spring retention feature is disposed between an aft side of the fuel plenum and the retention plate. The system further includes a spring which extends between the spring retention feature and the retention plate.

  19. 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.

  20. 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.

  1. Molybdenum Tube Characterization report

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-02-07

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

  2. 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...

  3. Wavy tube heat pumping

    Energy Technology Data Exchange (ETDEWEB)

    Haldeman, C. W.

    1985-12-03

    A PVC conduit about 4'' in diameter and a little more than 40 feet long is adapted for being seated in a hole in the earth and surrounds a coaxial copper tube along its length that carries Freon between a heat pump and a distributor at the bottom. A number of wavy conducting tubes located between the central conducting tube and the wall of the conduit interconnect the distributor with a Freon distributor at the top arranged for connection to the heat pump. The wavy conducting tubing is made by passing straight soft copper tubing between a pair of like opposed meshing gears each having four convex points in space quadrature separated by four convex recesses with the radius of curvature of each point slightly less than that of each concave recess.

  4. What Are Neural Tube Defects?

    Science.gov (United States)

    ... NICHD Research Information Clinical Trials Resources and Publications Neural Tube Defects (NTDs): Condition Information Skip sharing on social media links Share this: Page Content What are neural tube defects? Neural (pronounced NOOR-uhl ) tube defects are ...

  5. 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.

  6. Tube-Forming Assays.

    Science.gov (United States)

    Brown, Ryan M; Meah, Christopher J; Heath, Victoria L; Styles, Iain B; Bicknell, Roy

    2016-01-01

    Angiogenesis involves the generation of new blood vessels from the existing vasculature and is dependent on many growth factors and signaling events. In vivo angiogenesis is dynamic and complex, meaning assays are commonly utilized to explore specific targets for research into this area. Tube-forming assays offer an excellent overview of the molecular processes in angiogenesis. The Matrigel tube forming assay is a simple-to-implement but powerful tool for identifying biomolecules involved in angiogenesis. A detailed experimental protocol on the implementation of the assay is described in conjunction with an in-depth review of methods that can be applied to the analysis of the tube formation. In addition, an ImageJ plug-in is presented which allows automatic quantification of tube images reducing analysis times while removing user bias and subjectivity.

  7. Chest tube insertion - slideshow

    Science.gov (United States)

    ... presentations/100008.htm Chest tube insertion - series—Normal anatomy To use the sharing features ... pleural space is the space between the inner and outer lining of the lung. It is normally very thin, and lined only ...

  8. Snorkeling and Jones tubes

    OpenAIRE

    Lam, Lewis Y. W.; Weatherhead, Robert G.

    2015-01-01

    We report a case of tympanic membrane rupture during snorkeling in a 17-year-old young man who had previously undergone bilateral Jones tubes placed for epiphora. To our knowledge, this phenomenon has not been previously reported.

  9. Snorkeling and Jones tubes.

    Science.gov (United States)

    Lam, Lewis Y W; Weatherhead, Robert G

    2015-01-01

    We report a case of tympanic membrane rupture during snorkeling in a 17-year-old young man who had previously undergone bilateral Jones tubes placed for epiphora. To our knowledge, this phenomenon has not been previously reported.

  10. Nasogastric feeding tube

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000182.htm Nasogastric feeding tube To use the sharing features on this ... the nose. It can be used for all feedings or for giving a person extra calories. It ...

  11. Ear tube insertion - slideshow

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/presentations/100045.htm Ear tube insertion - series—Normal anatomy To use the ... 4 Overview The eardrum (tympanic membrane) separates the ear canal from the middle ear. Review Date 8/ ...

  12. 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.

  13. Using a nasogastric tube.

    Science.gov (United States)

    Candy, C

    1986-09-01

    This discussion of the use of a nasogastric tube covers the equipment needed, the method, rehydration and feeding, prolonged nasogastric feeding, and stopping nasogastric feeding. A nasogastric tube is useful when children are unable to drink safely and in sufficient amounts for any of the following reasons: severe dehydration; if intravenous (IV) therapy is unavailable; low birth weight infants; or the child is drowsy or vomiting. Severely malnourished children may be fed initially in this way if they are too weak or anorexic to eat or drink normally. The following equipment is needed: nasogastric tube; lubricating fluid; a syringe; blue litmus paper, if available; adhesive tape; stethoscope if available; and fluid to be given. Explain to the child's parents and the child, if old enough to understand, what will be done; lie infants flat; measure the approximate length from the child's nostril to the ear lobe and then to the top of the abdomen with the tube and mark the position; clean the nostrils to remove the mucus, and lubricate the tip of the tube and gently insert into the nostril; give the child a drink of water if he or she is conscious; continue to pass the tube down until the position marked reaches the nostril; use the syringe to suck up some fluid and test with blue litmus paper to check that the tube is in the stomach; and inject 5-10 ml of fluid (saline or oral rehydration solution, not milk formula) by syringe if satisfied the tube is in the correct position. Where possible, give a continuous drip of fluid. If this is not possible, give frequent small amounts using the syringe as a funnel. If feeding continues for more than 24 hours, clean the nostrils daily with warm water and change the tube to the other nostril every few days. Also keep the mouth very clean with a dilute solution of 8% sodium bicarbonate, if available, or citrus fruit juice. To remove the tube, remove the adhesive tape, take the tube out gently and smoothly, and offer the child a

  14. Magnesium tube hydroforming

    Energy Technology Data Exchange (ETDEWEB)

    Liewald, M.; Pop, R. [Institute for Metal Forming Technology (IFU), Stuttgart (Germany)

    2008-04-15

    Magnesium alloys reveal a good strength-to-weight ratio in the family of lightweight metals and gains potential to provide up to 30% mass savings compared to aluminium and up to 75 % compared to steel. The use of sheet magnesium alloys for auto body applications is however limited due to the relatively low formability at room temperature. Within the scope of this paper, extruded magnesium tubes, which are suitable for hydroforming applications, have been investigated. Results obtained at room temperature using magnesium AZ31 tubes show that circumferential strains are limited to a maximal value of 4%. In order to examine the influence of the forming temperature on tube formability, investigations have been carried out with a new die set for hot internal high pressure (IHP) forming at temperatures up to 400 C. Earlier investigations with magnesium AZ31 tubes have shown that fractures occur along the welding line at tubes extruded over a spider die, whereby a non-uniform expansion at bursting with an elongation value of 24% can be observed. A maximum circumferential strain of approx. 60% could be attained when seamless, mechanically pre-expanded and annealed tubes of the same alloy have been used. The effect of annealing time on materials forming properties shows a fine grained structure for sufficient annealing times as well as deterioration with a large increase at same time. Hence, seamless ZM21 tubes have been used in the current investigations. With these tubes, an increased tensile fracture strain of 116% at 350 C is observed as against 19% at 20 C, obtained by tensile testing of milled specimens from the extruded tubes. This behaviour is also seen under the condition of tool contact during the IHP forming process. To determine the maximum circumferential strain at different forming temperatures and strain rates, the tubes are initially bulged in a die with square cross-section under plane stress conditions. Thereafter, the tubes are calibrated by using an

  15. 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,

  16. 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.

  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. 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.

  19. NEI You Tube Videos: Amblyopia

    Medline Plus

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

  20. 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.

  1. 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.

  2. Tracheostomy tubes and related appliances.

    Science.gov (United States)

    Hess, Dean R

    2005-04-01

    Tracheostomy tubes are used to administer positive-pressure ventilation, to provide a patent airway, to provide protection from aspiration, and to provide access to the lower respiratory tract for airway clearance. They are available in a variety of sizes and styles, from several manufacturers. The dimensions of tracheostomy tubes are given by their inner diameter, outer diameter, length, and curvature. Differences in length between tubes of the same inner diameter, but from different manufacturers, are not commonly appreciated but may have important clinical implications. Tracheostomy tubes can be angled or curved, a feature that can be used to improve the fit of the tube in the trachea. Extra proximal length tubes facilitate placement in patients with large necks, and extra distal length tubes facilitate placement in patients with tracheal anomalies. Several tube designs have a spiral wire reinforced flexible design and have an adjustable flange design to allow bedside adjustments to meet extra-length tracheostomy tube needs. Tracheostomy tubes can be cuffed or uncuffed. Cuffs on tracheostomy tubes include high-volume low-pressure cuffs, tight-to-shaft cuffs, and foam cuffs. The fenestrated tracheostomy tube has an opening in the posterior portion of the tube, above the cuff, which allows the patient to breathe through the upper airway when the inner cannula is removed. Tracheostomy tubes with an inner cannula are called dual-cannula tracheostomy tubes. Several tracheostomy tubes are designed specifically for use with the percutaneous tracheostomy procedure. Others are designed with a port above the cuff that allows for subglottic aspiration of secretions. The tracheostomy button is used for stoma maintenance. It is important for clinicians caring for patients with a tracheostomy tube to understand the nuances of various tracheostomy tube designs and to select a tube that appropriately fits the patient.

  3. Heat-shrink plastic tubing seals joints in glass tubing

    Science.gov (United States)

    Del Duca, B.; Downey, A.

    1968-01-01

    Small units of standard glass apparatus held together by short lengths of transparent heat-shrinkable polyolefin tubing. The tubing is shrunk over glass O-ring type connectors having O-rings but no lubricant.

  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. The thermal tube

    Energy Technology Data Exchange (ETDEWEB)

    Semena, M.G.

    1980-08-30

    A thermal tube is proposed which contains a layer of dielectric, capillary porous material located on the internal surface of the body. To increase the heat transmitting capability, the layer of capillary porous material is made in the form of a felting, formed by hollow fibers from a non-alkaline, borosilicate glass.

  6. 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,

  7. Cladding tube manufacturing technology

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-04-01

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

  8. Misdirected Minitracheostomy Tube

    Science.gov (United States)

    Singh, Ajmer; Nanda, Chinmaya; Mehta, Yatin

    2017-01-01

    We report a patient who after an uneventful coronary artery bypass graft surgery and left ventricular aneurysmorrhaphy developed intracerebral hemorrhage and subsequently required minitracheostomy. Chest X-ray showed misdirected minitracheostomy tube facing upward toward the laryngeal opening which was repositioned using bronchoscope. PMID:28074805

  9. Misdirected minitracheostomy tube

    Directory of Open Access Journals (Sweden)

    Ajmer Singh

    2017-01-01

    Full Text Available We report a patient who after an uneventful coronary artery bypass graft surgery and left ventricular aneurysmorrhaphy developed intracerebral hemorrhage and subsequently required minitracheostomy. Chest X-ray showed misdirected minitracheostomy tube facing upward toward the laryngeal opening which was repositioned using bronchoscope.

  10. 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)

  11. 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

  12. 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…

  13. 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.

  14. Vortex tube optimization theory

    Energy Technology Data Exchange (ETDEWEB)

    Lewins, Jeffery [Cambridge Univ., Magdalene Coll., Cambridge (United Kingdom); Bejan, Adrian [Duke Univ., Dept. of Mechanical Engineering and Materials Science, Durham, NC (United States)

    1999-11-01

    The Ranque-Hilsch vortex tube splits a single high pressure stream of gas into cold and warm streams. Simple models for the vortex tube combined with regenerative precooling are given from which an optimisation can be undertaken. Two such optimisations are needed: the first shows that at any given cut or fraction of the cold stream, the best refrigerative load, allowing for the temperature lift, is nearly half the maximum loading that would result in no lift. The second optimisation shows that the optimum cut is an equal division of the vortex streams between hot and cold. Bounds are obtainable within this theory for the performance of the system for a given gas and pressure ratio. (Author)

  15. A wandering tube.

    Science.gov (United States)

    Dubin, Ina; Gelber, Moshe; Schattner, Ami

    2016-12-05

    The predominant causes of acute mechanical small bowel obstruction in geriatric patients are adhesions and hernias, which is not much different than in other adult age groups. Unusual etiologies may be encountered, such as volvulus or gallstone ileus, but a displaced feeding gastrostomy tube is a distinctly rare cause of intestinal obstruction which needs to be considered by emergency physicians as it may be increasingly encountered.

  16. 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.

  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. 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.

  19. Hybrid endotracheal tubes

    Science.gov (United States)

    Sakezles, Christopher Thomas

    Intubation involves the placement of a tube into the tracheal lumen and is prescribed in any setting in which the airway must be stabilized or the patient anesthetized. The purpose of the endotracheal tube in these procedures is to maintain a viable airway, facilitate mechanical ventilation, allow the administration of anesthetics, and prevent the reflux of vomitus into the lungs. In order to satisfy these requirements a nearly airtight seal must be maintained between the tube and the tracheal lining. Most conventional endotracheal tubes provide this seal by employing a cuff that is inflated once the tube is in place. However, the design of this cuff and properties of the material are a source of irritation and injury to the tracheal tissues. In fact, the complication rate for endotracheal intubation is reported to be between 10 and 60%, with manifestations ranging from severe sore throat to erosion through the tracheal wall. These complications are caused by a combination of the materials employed and the forces exerted by the cuff on the tracheal tissues. In particular, the abrasive action of the cuff shears cells from the lining, epithelium adhering to the cuff is removed during extubation, and normal forces exerted on the basement tissues disrupt the blood supply and cause pressure necrosis. The complications associated with tracheal intubation may be reduced or eliminated by employing airway devices constructed from hydrogel materials. Hydrogels are a class of crosslinked polymers which swell in the presence of moisture, and may contain more than 95% water by weight. For the current study, several prototype airway devices were constructed from hydrogel materials including poly(vinyl alcohol), poly(hydroxyethyl methacrylate), and poly(vinyl pyrrolidone). The raw hydrogel materials from this group were subjected to tensile, swelling, and biocompatibility testing, while the finished devices were subjected to extensive mechanical simulation and animal trials

  20. Lava Tube Collapse Pits

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] We will be looking at collapse pits for the next two weeks. Collapse pits on Mars are formed in several ways. In volcanic areas, channelized lava flows can form roofs which insulate the flowing lava. These features are termed lava tubes on Earth and are common features in basaltic flows. After the lava has drained, parts of the roof of the tube will collapse under its own weight. These collapse pits will only be as deep as the bottom of the original lava tube. Another type of collapse feature associated with volcanic areas arises when very large eruptions completely evacuate the magma chamber beneath the volcano. The weight of the volcano will cause the entire edifice to subside into the void space below it. Structural features including fractures and graben will form during the subsidence. Many times collapse pits will form within the graben. In addition to volcanic collapse pits, Mars has many collapse pits formed when volatiles (such as subsurface ice) are released from the surface layers. As the volatiles leave, the weight of the surrounding rock causes collapse pits to form. These collapse pits are found in the southern hemisphere of Mars. They are likely lava tube collapse pits related to flows from Hadriaca Patera. Image information: VIS instrument. Latitude -36.8, Longitude 89.6 East (270.4 West). 19 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D

  1. Tube coalescence in the Jingfudong lava tube and implications for lava flow hazard of Tengchong volcanism

    OpenAIRE

    Zhengquan Chen; Yongshun Liu; Haiquan Wei; Jiandong Xu; Wenfeng Guo

    2016-01-01

    Tube-fed structure occurs as a general phenomenon in Tengchong basic lavas, such as lava tubes, lava plugs and tube-related collapse depressions. We deduced the development of Laoguipo lava flows, which is the longest lava tube (Jingfudong lava tube) evolved in Tengchong volcanic area. Following the detailed documentation of the tube morphology of the Jingfudong lava tube, we propose that the Jingfudong lava tube was formed through vertical coalescence of at least three tubes. The coalescence...

  2. 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.

  3. Diffusion in a Curved Tube

    OpenAIRE

    Ogawa, Naohisa

    2011-01-01

    The diffusion of particles in confining walls forming a tube is discussed. Such a transport phenomenon is observed in biological cells and porous media. We consider the case in which the tube is winding with curvature and torsion, and the thickness of the tube is sufficiently small compared with its curvature radius. We discuss how geomerical quantities appear in a quasi-one-dimensional diffusion equation.

  4. The special relativistic shock tube

    Science.gov (United States)

    Thompson, Kevin W.

    1986-01-01

    The shock-tube problem has served as a popular test for numerical hydrodynamics codes. The development of relativistic hydrodynamics codes has created a need for a similar test problem in relativistic hydrodynamics. The analytical solution to the special relativistic shock-tube problem is presented here. The relativistic shock-jump conditions and rarefaction solution which make up the shock tube are derived. The Newtonian limit of the calculations is given throughout.

  5. Tubing for augmented heat transfer

    Energy Technology Data Exchange (ETDEWEB)

    Yampolsky, J.S.; Pavlics, P.

    1983-08-01

    The objectives of the program reported were: to determine the heat transfer and friction characteristics on the outside of spiral fluted tubing in single phase flow of water, and to assess the relative cost of a heat exchanger constructed with spiral fluted tubing with one using conventional smooth tubing. An application is examined where an isolation water/water heat exchanger was used to transfer the heat from a gaseous diffusion plant to an external system for energy recovery. (LEW)

  6. 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.

  7. 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…

  8. Method for producing a tube

    Science.gov (United States)

    Peterson, Kenneth A.; Rohde, Steven B.; Pfeifer, Kent B.; Turner, Timothy S.

    2007-01-02

    A method is described for producing tubular substrates having parallel spaced concentric rings of electrical conductors that can be used as the drift tube of an Ion Mobility Spectrometer (IMS). The invention comprises providing electrodes on the inside of a tube that are electrically connected to the outside of the tube through conductors that extend between adjacent plies of substrate that are combined to form the tube. Tubular substrates are formed from flexible polymeric printed wiring board materials, ceramic materials and material compositions of glass and ceramic, commonly known as Low Temperature Co-Fired Ceramic (LTCC). The adjacent plies are sealed together around the electrode.

  9. 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.

  10. Charm production in flux tubes

    CERN Document Server

    Aguiar, C E; Nazareth, R A M S; Pech, G

    1996-01-01

    We argue that the non-perturbative Schwinger mechanism may play an important role in the hadronic production of charm. We present a flux tube model which assumes that the colliding hadrons become color charged because of gluon exchange, and that a single non-elementary flux tube is built up as they recede. The strong chromoelectric field inside this tube creates quark pairs (including charmed ones) and the ensuing color screening breaks the tube into excited hadronic clusters. On their turn these clusters, or `fireballs', decay statistically into the final hadrons. The model is able to account for the soft production of charmed, strange and lighter hadrons within a unified framework.

  11. Charm production in flux tubes

    Science.gov (United States)

    Aguiar, C. E.; Kodama, T.; Nazareth, R. A. M. S.; Pech, G.

    1996-01-01

    We argue that the nonperturbative Schwinger mechanism may play an important role in the hadronic production of charm. We present a flux tube model which assumes that the colliding hadrons become color charged because of gluon exchange, and that a single nonelementary flux tube is built up as they recede. The strong chromoelectric field inside this tube creates quark pairs (including charmed ones) and the ensuing color screening breaks the tube into excited hadronic clusters. In their turn these clusters, or ``fireballs,'' decay statistically into the final hadrons. The model is able to account for the soft production of charmed, strange, and lighter hadrons within a unified framework.

  12. Effect of the sequence of tube rolling in a tube bundle of a shell and tube heat exchanger on the stress-deformed state of the tube sheet

    Science.gov (United States)

    Tselishchev, M. F.; Plotnikov, P. N.; Brodov, Yu. M.

    2015-11-01

    Rolling the tube sheet of a heat exchanger with U-shaped tubes, as exemplified by the vapor cooler GP-24, was simulated. The simulation was performed using the finite element method with account of elas- tic-plastic properties of the tube and tube sheet materials. The simulation consisted of two stages; at the first stage, maximum and residual contact stress in the conjunction of a separate tube and the tube sheet was determined using the "equivalent sleeve" model; at the second stage, the obtained contact stress was applied to the hole surface in the tube sheet. Thus, different tube rolling sequences were simulated: from the center to the periphery of the tube sheet and from the periphery to the center along a spiral line. The studies showed that the tube rolling sequence noticeably influences the value of the tube sheet residual deflection for the same rolling parameters of separate tubes. Residual deflection of the tube sheet in different planes was determined. It was established that the smallest residual deflection corresponds to the tube rolling sequence from the periphery to the center of the tube sheet. The following dependences were obtained for different rolling sequences: maximum deformation of the tube sheet as a function of the number of rolled tubes, residual deformation of the tube sheet along its surface, and residual deflection of the tube sheet as a function of the rotation angle at the periphery. The preferred sequence of tube rolling for minimizing the tube sheet deformation is indicated.

  13. 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.

  14. Explosive welding of a tube into a tube sheet

    Energy Technology Data Exchange (ETDEWEB)

    Green, Sheryll C. (London, OH); Linse, Vonne D. (Columbus, OH)

    1978-10-03

    A cartridge containing an explosive charge is placed within a tube assembled within a tube sheet. The charge is detonated through use of a detonator cord containing a minimum but effective amount of explosive material. The cord is contained inside a tubular shield throughout most of its length within the cartridge. A small length of the cord extends beyond the tubular shield to contact and detonate the explosive charge in its rear portion near the cartridge base. The cartridge base is provided of substantial mass and thickness in respect to side and front walls of the cartridge to minimize bulging beyond the rear face of the tube sheet. For remote activation an electrically activated detonator of higher charge density than the cord is attached to the cord at a location spaced from the tube sheet, cartridge and tube.

  15. Explosive welding of a tube into a tube sheet

    Energy Technology Data Exchange (ETDEWEB)

    Green, S.C.; Linse, V.D.

    1978-10-03

    A cartridge containing an explosive charge is placed within a tube assembled within a tube sheet. The charge is detonated through use of a detonator cord containing a minimum but effective amount of explosive material. The cord is contained inside a tubular shield throughout most of its length within the cartridge. A small length of the cord extends beyond the tublar shield to contact and detonate the explosive charge in its rear portion near the cartridge base. The cartridge base is provided of substantial mass and thickness in respect to side and front walls of the cartridge to minimize bulging beyond the rear face of the tube sheet. For remote activation an electrically activated detonator of higher charge density than the cord is attached to the cord at a location spaced from the tube sheet, cartridge and tube.

  16. 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.

  17. Piezoelectric Rotary Tube Motor

    Science.gov (United States)

    Fisher, Charles D.; Badescu, Mircea; Braun, David F.; Culhane, Robert

    2011-01-01

    A custom rotary SQUIGGLE(Registered TradeMark) motor has been developed that sets new benchmarks for small motor size, high position resolution, and high torque without gear reduction. Its capabilities cannot be achieved with conventional electromagnetic motors. It consists of piezoelectric plates mounted on a square flexible tube. The plates are actuated via voltage waveforms 90 out of phase at the resonant frequency of the device to create rotary motion. The motors were incorporated into a two-axis postioner that was designed for fiber-fed spectroscopy for ground-based and space-based projects. The positioner enables large-scale celestial object surveys to take place in a practical amount of time.

  18. Primary Fallopian Tube Carcinoma

    Directory of Open Access Journals (Sweden)

    Prasad K Shetty

    2011-01-01

    Full Text Available Primary Fallopian Tube Carcinoma (PFTC is rare and accounts for about 0.3% of all gynecologic cancers. Less than 1500 cases have been reported in the literature. It arises in postmenopausal women and typically presents with abdominal pelvic pain, vaginal bleeding and watery discharge. However, a correct diagnosis is rarely achieved preoperative, and in many cases, the diagnosis is made after incidental surgery for unrelated conditions commonly being ovarian carcinoma . Compared with ovarian carcinoma, PFTC more often presents at early stages, but it has a worse prognosis. PFTC is usually managed in the same manner as ovarian cancer. We report a case of Left PFTC that presented as Left ovarian mass, and we briefly review the literature.

  19. Flaming on YouTube

    NARCIS (Netherlands)

    Moor, Peter J.; Heuvelman, A.; Verleur, R.

    2010-01-01

    In this explorative study, flaming on YouTube was studied using surveys of YouTube users. Flaming is defined as displaying hostility by insulting, swearing or using otherwise offensive language. Three general conclusions were drawn. First, although many users said that they themselves do not flame,

  20. Interpreting Shock Tube Ignition Data

    Science.gov (United States)

    2003-10-01

    times only for high concentrations (of order 1% fuel or greater). The requirements of engine (IC, HCCI , CI and SI) modelers also present a different...Paper 03F-61 Interpreting Shock Tube Ignition Data D. F. Davidson and R. K. Hanson Mechanical Engineering ... Engineering Department Stanford University, Stanford CA 94305 Abstract Chemical kinetic modelers make extensive use of shock tube ignition data

  1. 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,

  2. Water-storage-tube systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hemker, P.

    1981-12-24

    Passive solar collection/storage/distribution systems were surveyed, designed, fabricated, and mechanically and thermally tested. The types studied were clear and opaque fiberglass tubes, metal tubes with plastic liners, and thermosyphoning tubes. (MHR)

  3. 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.

  4. Acoustical studies on corrugated tubes

    Science.gov (United States)

    Balaguru, Rajavel

    Corrugated tubes and pipes offer greater global flexibility combined with local rigidity. They are used in numerous engineering applications such as vacuum cleaner hosing, air conditioning systems of aircraft and automobiles, HVAC control systems of heating ducts in buildings, compact heat exchangers, medical equipment and offshore gas and oil transportation flexible riser pipelines. Recently there has been a renewed research interest in analyzing the flow through a corrugated tube to understand the underlying mechanism of so called whistling, although the whistling in such a tube was identified in early twentieth century. The phenomenon of whistling in a corrugated tube is interesting because an airflow through a smooth walled tube of similar dimensions will not generate any whistling tones. Study of whistling in corrugated tubes is important because, it not only causes an undesirable noise problem but also results in flow-acoustic coupling. Such a coupling can cause significant structural vibrations due to flow-acoustic-structure interaction. This interaction would cause flow-induced vibrations that could result in severe damage to mechanical systems having corrugated tubes. In this research work, sound generation (whistling) in corrugated tubes due to airflow is analyzed using experimental as well as Computational Fluid Dynamics-Large Eddy Simulation (CFD-LES) techniques. Sound generation mechanisms resulting in whistling have been investigated. The whistling in terms of frequencies and sound pressure levels for different flow velocities are studied. The analytical and experimental studies are carried out to understand the influence of various parameters of corrugated tubes such as cavity length, cavity width, cavity depth, pitch, Reynolds numbers and number of corrugations. The results indicate that there is a good agreement between theoretically calculated, computationally predicted and experimentally measured whistling frequencies and sound pressure levels

  5. 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

  6. 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.

  7. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... questions Clinical Studies Publications Catalog Photos and Images Spanish Language Information Dilated Exam Grants and Funding Extramural ... Low Vision Refractive Errors Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded video ...

  8. Tube-wave seismic imaging

    Science.gov (United States)

    Korneev, Valeri A [LaFayette, CA

    2009-05-05

    The detailed analysis of cross well seismic data for a gas reservoir in Texas revealed two newly detected seismic wave effects, recorded approximately 2000 feet above the reservoir. A tube-wave (150) is initiated in a source well (110) by a source (111), travels in the source well (110), is coupled to a geological feature (140), propagates (151) through the geological feature (140), is coupled back to a tube-wave (152) at a receiver well (120), and is and received by receiver(s) (121) in either the same (110) or a different receiving well (120). The tube-wave has been shown to be extremely sensitive to changes in reservoir characteristics. Tube-waves appear to couple most effectively to reservoirs where the well casing is perforated, allowing direct fluid contact from the interior of a well case to the reservoir.

  9. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... questions Clinical Studies Publications Catalog Photos and Images Spanish Language Information Grants and Funding Extramural Research Division ... Low Vision Refractive Errors Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded video ...

  10. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... Grants and Funding Extramural Research Division of Extramural Science Programs Division of Extramural Activities Extramural Contacts NEI ... Amaurosis Low Vision Refractive Errors Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded ...

  11. Pulse tube refrigerator; Parusukan reitoki

    Energy Technology Data Exchange (ETDEWEB)

    Hozumi, Yoshikazu [University of Tsukuba, Tsukuba (Japan); Shiraishi, Masao [Hiroshima University, Hiroshima (Japan)

    1999-06-05

    In the cryogenic field, high temperature superconductivity and research and development of the peripheral technology are popular. Refrigerating machine development of the very low temperature is also one of the results. Research and development are mainly advanced as a refrigerating machine of the center for the aerospace plane installation. There is special and small very low temperature refrigerating machine called 'the pulse tube refrigerating machine' of which the practical application is also recently being attempted for the semiconductor cooling using high temperature superconductivity. At present, the basic research of elucidation of refrigeration phenomenon of pulse tube refrigerating machine and development of high-performance pulse tube refrigerating machine is carried out by experiment in the Ministry of International Trade and Industry Mechanical Engineering Lab., Agency of Industrial Sci. and Technology and numerical simulation in Chiyoda Corp. In this report, the pulse tube refrigerating machine is introduced, and the application in the chemical engineering field is considered. (NEDO)

  12. 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.

  13. Tube wall thickness measurement apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Lagasse, P.R.

    1987-01-06

    An apparatus is described for measuring the thickness of a tube's wall for the tube's entire length and circumference by determining the deviation of the tube wall thickness from the known thickness of a selected standard item, the apparatus comprising: a. a base; b. a first support member having first and second ends, the first end being connected to the base, the first support member having a sufficiently small circumference that the tube can be slid over the first support member; c. a spherical element, the spherical element being connected to the second end of the first support member. The spherical element has a sufficiently small circumference at its equator that the tube can be slid over the spherical element, the spherical element having at its equator a larger circumference than the first support member; d. a second support member having first and second ends, the first end being connected to the base, the second support member being spaced apart form the first support member; e. a positioning element connected to and moveable relative to the second support member; and f. an indicator connected to the positioning element and being moveable thereby to a location proximate the spherical element. The indicator includes a contact ball for contacting the selected standard item and holding it against the spherical element, the contact ball contacting the tube when the tube is disposed about the spherical element. The indicator includes a dial having a rotatable needle for indicating the deviation of the tube wall thickness from the thickness of the selected standard item, the rotatable needle being operatively connected to and responsive to the position of the contact ball.

  14. Tube wall thickness measurement apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Lagasse, P.R.

    1985-06-21

    An apparatus for measuring the thickness of a tube's wall for the tube's entire length and radius by determining the deviation of the tube wall thickness from the known thickness of a selected standard item. The apparatus comprises a base and a first support member having first and second ends. The first end is connected to the base and the second end is connected to a spherical element. A second support member is connected to the base and spaced apart from the first support member. A positioning element is connected to and movable relative to the second support member. An indicator is connected to the positioning element and is movable to a location proximate the spherical element. The indicator includes a contact ball for first contacting the selected standard item and holding it against the spherical element. The contact ball then contacts the tube when the tube is disposed about the spherical element. The indicator includes a dial having a rotatable needle for indicating the deviation of the tube wall thickness from the thickness of the selected standard item.

  15. Tube wall thickness measurement apparatus

    Science.gov (United States)

    Lagasse, P.R.

    1985-06-21

    An apparatus for measuring the thickness of a tube's wall for the tube's entire length and radius by determining the deviation of the tube wall thickness from the known thickness of a selected standard item. The apparatus comprises a base and a first support member having first and second ends. The first end is connected to the base and the second end is connected to a spherical element. A second support member is connected to the base and spaced apart from the first support member. A positioning element is connected to and movable relative to the second support member. An indicator is connected to the positioning element and is movable to a location proximate the spherical element. The indicator includes a contact ball for first contacting the selected standard item and holding it against the spherical element. The contact ball then contacts the tube when the tube is disposed about the spherical element. The indicator includes a dial having a rotatable needle for indicating the deviation of the tube wall thickness from the thickness of the selected standard item.

  16. Tube wall thickness measurement apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Lagasse, Paul R. (Santa Fe, NM)

    1987-01-01

    An apparatus for measuring the thickness of a tube's wall for the tube's entire length and circumference by determining the deviation of the tube wall thickness from the known thickness of a selected standard item. The apparatus comprises a base and a first support member having first and second ends. The first end is connected to the base and the second end is connected to a spherical element. A second support member is connected to the base and spaced apart from the first support member. A positioning element is connected to and movable relative to the second support member. An indicator is connected to the positioning element and is movable to a location proximate the spherical element. The indicator includes a contact ball for first contacting the selected standard item and holding it against the spherical element. The contact ball then contacts the tube when the tube is disposed about the spherical element. The indicator includes a dial having a rotatable needle for indicating the deviation of the tube wall thickness from the thickness of the selected standard item.

  17. 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.

  18. 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.

  19. Free Piston Double Diaphragm Shock Tube

    OpenAIRE

    OGURA, Eiji; FUNABIKI, Katsushi; SATO, Shunichi; Abe, Takashi; 小倉, 栄二; 船曳, 勝之; 佐藤, 俊逸; 安部, 隆士

    1997-01-01

    A free piston double diaphragm shock tube was newly developed for generation of high Mach number shock wave. Its characteristics was investigated for various operation parameters; such as a strength of the diaphragm at the end of the comparession tube, an initial pressure of low pressure tube, an initial pressure of medium pressure tube and the volume of compression tube. Under the restriction of fixed pressures for the driver high pressure tube (32×10^5Pa) and the low pressure tube (40Pa) in...

  20. 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...... portion acts to alternately close and open the valve members thereby generating a fluid flow through the tube. The invention further relates to a pump element comprising at least two non-return valve members connected by a rod element, and for insertion in an at least partly flexible tube in such tube...... 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...

  1. 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...

  2. Drift tubes of Linac 2

    CERN Multimedia

    1977-01-01

    With the advent of the 800 MeV PS Booster in 1972, the original injector of the PS, a 50 MeV Alvarez-type proton linac, had reached its limits, in terms of intensity and stability. In 1973 one therefore decided to build a new linac (Linac 2), also with a drift-tube Alvarez structure and an energy of 50 MeV. It had a new Cockcroft-Walton preinjector with 750 keV, instead of the previous one with 500 keV. Linac 2 was put into service in 1980. The old Linac 1 was then used for the study of, and later operation with, various types of ions. This picture shows Linac 2 drift-tubes, suspended on stems coming from the top, in contrast to Linac 1, where the drift-tubes stood on stems coming from the bottom.

  3. [The Use of a Tracheal Tube for Guiding Nasogastric Tube Insertion].

    Science.gov (United States)

    Saima, Shunsuke; Asai, Takashi; Okuda, Yasuhisa

    2016-04-01

    An obese patient was scheduled for shoulder joint surgery under general anesthesia. After induction of anesthesia and tracheal intubation, insertion of a gastric tube was difficult. A new tracheal tube was prepared, the connecter was removed, and the tube was cut longitudinally. The tube was inserted orally into the esophagus. A gastric tube was passed through the nose, and its tip was taken out of the mouth. The tip of the gastric tube was passed through the tracheal tube, and its correct position in the stomach was confirmed by auscultation of the epigastrium. The tracheal tube was carefully taken out from the esophagus leaving the gastric tube in the stomach. The cut tracheal tube was peeled off from the gastric tube. Correct positioning of the gastric tube was re-confirmed.

  4. Working session 3: Tubing integrity

    Energy Technology Data Exchange (ETDEWEB)

    Cueto-Felgueroso, C. [Tecnatom, S.A., San Sebastian de los Reyes, Madrid (Spain); Strosnider, J. [NRC, Washington, DC (United States)

    1997-02-01

    Twenty-three individuals representing nine countries (Belgium, Canada, the Czech Republic, France, Japan, the Slovak Republic, Spain, the UK, and the US) participated in the session on tube integrity. These individuals represented utilities, vendors, consultants and regulatory authorities. The major subjects discussed by the group included overall objectives of managing steam generator tube degradation, necessary elements of a steam generator degradation management program, the concept of degradation specific management, structural integrity evaluations, leakage evaluations, and specific degradation mechanisms. The group`s discussions on these subjects, including conclusions and recommendations, are summarized in this article.

  5. Anatomy of the Eustachian Tube.

    Science.gov (United States)

    Leuwer, Rudolf

    2016-10-01

    The eustachian tube consists of 2 compartments: the Rüdinger's safety canal and the auxiliary gap. It is surrounded by a cartilaginous wall on the craniomedial side and a membranous wall on the inferolateral side. The eustachian tube cartilage is firmly attached to the skull base by the lateral and the medial suspensory ligaments, which are separated by the medial Ostmann fat pad. The function of the isometric tensor veli palatini muscle is modulated by hypomochlia, which have an influence on the muscular force vectors.

  6. Orifice plates and venturi tubes

    CERN Document Server

    Reader-Harris, Michael

    2015-01-01

    This book gives the background to differential-pressure flow measurement and goes through the requirements explaining the reason for them. For those who want to use an orifice plate or a Venturi tube the standard ISO 5167 and its associated Technical Reports give the instructions required.  However, they rarely tell the users why they should follow certain instructions.  This book helps users of the ISO standards for orifice plates and Venturi tubes to understand the reasons why the standards are as they are, to apply them effectively, and to understand the consequences of deviations from the standards.

  7. Mechanical Instabilities of Biological Tubes

    Science.gov (United States)

    Hannezo, Edouard; Prost, Jacques; Joanny, Jean-François

    2012-07-01

    We study theoretically the morphologies of biological tubes affected by various pathologies. When epithelial cells grow, the negative tension produced by their division provokes a buckling instability. Several shapes are investigated: varicose, dilated, sinuous, or sausagelike. They are all found in pathologies of tracheal, renal tubes, or arteries. The final shape depends crucially on the mechanical parameters of the tissues: Young’s modulus, wall-to-lumen ratio, homeostatic pressure. We argue that since tissues must be in quasistatic mechanical equilibrium, abnormal shapes convey information as to what causes the pathology. We calculate a phase diagram of tubular instabilities which could be a helpful guide for investigating the underlying genetic regulation.

  8. Manually operated piston-driven shock tube

    OpenAIRE

    Reddy, KPJ; Sharath, N

    2013-01-01

    A simple hand-operated shock tube capable of producing Mach 2 shock waves is described. Performance of this miniature shock tube using compressed high pressure air created by a manually operated piston in the driver section of the shock tube as driver gas with air at 1 atm pressure as the test gas in the driven tube is presented. The performance of the shock tube is found to match well with the theoretically estimated values using normal shock relations. Applications of this shock tube named ...

  9. 21 CFR 876.5980 - Gastrointestinal tube and accessories.

    Science.gov (United States)

    2010-04-01

    ... intubation, feeding tube, gastroenterostomy tube, Levine tube, nasogastric tube, single lumen tube with... § 876.9. (2) Class I (general controls) for the dissolvable nasogastric feed tube guide for the nasogastric tube. The class I device is exempt from the premarket notification procedures in subpart E of...

  10. OurTube / David Talbot

    Index Scriptorium Estoniae

    Talbot, David

    2009-01-01

    USA California Ülikooli töötajate Abram Stern'i ja Michael Dale'i poolt 2005. a. algatatud USA kongressis peetud kõnede videoremiksidest ja nende poolt loodud veebisaidist Metavid.org. Ka YouTube keskkonnast ja wikipedia katsetustest muuta oma keskkond multimeedialisemaks

  11. Kundt's Tube Experiment Using Smartphones

    Science.gov (United States)

    Parolin, Sara Orsola; Pezzi, Giovanni

    2015-01-01

    This article deals with a modern version of Kundt's tube experiment. Using economic instruments and a couple of smartphones, it is possible to "see" nodes and antinodes of standing acoustic waves in a column of vibrating air and to measure the speed of sound.

  12. Holography and the Future Tube

    CERN Document Server

    Gibbons, G W

    2000-01-01

    The Future Tube $T^+_n$ of n-dimensional Minkowski spacetime may be identified with the reduced phase space or ` ` space of motions" of a particle moving in (n+1)-dimensional Anti-de-Sitter spacetime. Both are isomorphic to a bounded homogeneous domain in ${\\bf C}^{n}$ whose Shilov boundary may be identified with $n$-dimensional conformally compactified Minkowski spacetime.

  13. Working session 1: Tubing degradation

    Energy Technology Data Exchange (ETDEWEB)

    Kharshafdjian, G. [Atomic Energy of Canada, Mississauga, Ontario (Canada); Turluer, G. [IPSN, Fontenay-aux-Roses (France)

    1997-02-01

    A general introductory overview of the purpose of the group and the general subject area of SG tubing degradation was given by the facilitator. The purpose of the session was described as to {open_quotes}develop conclusions and proposals on regulatory and technical needs required to deal with the issues of SG tubing degradation.{close_quotes} Types, locations and characteristics of tubing degradation in steam generators were briefly reviewed. The well-known synergistic effects of materials, environment, and stress and strain/strain rate, subsequently referred to by the acronym {open_quotes}MESS{close_quotes} by some of the group members, were noted. The element of time (i.e., evolution of these variables with time) was emphasized. It was also suggested that the group might want to consider the related topics of inspection capabilities, operational variables, degradation remedies, and validity of test data, and some background information in these areas was provided. The presentation given by Peter Millet during the Plenary Session was reviewed; Specifically, the chemical aspects and the degradation from the secondary side of the steam generator were noted. The main issues discussed during the October 1995 EPRI meeting on secondary side corrosion were reported, and a listing of the potential SG tube degradations was provided and discussed.

  14. Kundt's Tube Experiment Using Smartphones

    Science.gov (United States)

    Parolin, Sara Orsola; Pezzi, Giovanni

    2015-01-01

    This article deals with a modern version of Kundt's tube experiment. Using economic instruments and a couple of smartphones, it is possible to "see" nodes and antinodes of standing acoustic waves in a column of vibrating air and to measure the speed of sound.

  15. Fin-tube solar collectors

    Science.gov (United States)

    1980-01-01

    Report presents test procedures and results of thermal-performance evaluation of seven commercial fin tube (liquid) solar collector-absorber plates. Tests were conducted indoors at Marshall Space Flight Center Solar simulator. Results are graphically shown along with supporting test data and summary, indicating efficiency as function of collector inlet temperature.

  16. OurTube / David Talbot

    Index Scriptorium Estoniae

    Talbot, David

    2009-01-01

    USA California Ülikooli töötajate Abram Stern'i ja Michael Dale'i poolt 2005. a. algatatud USA kongressis peetud kõnede videoremiksidest ja nende poolt loodud veebisaidist Metavid.org. Ka YouTube keskkonnast ja wikipedia katsetustest muuta oma keskkond multimeedialisemaks

  17. Thermal inhomogeneities in vortex tubes

    Science.gov (United States)

    Lemesh, N. I.; Senchuk, L. A.

    An experimental study of the effect of the temperature of the inlet gas on the temperature difference between the hot and cold streams discharged from a Ranque-Hilsch vortex tube is described. The experimental results are presented in graphical form. It is that the temperature difference increases with the temperature of the entering gas.

  18. Welding the CNGS decay tube

    CERN Multimedia

    Maximilien Brice

    2004-01-01

    3.6 km of welds were required for the 1 km long CERN Neutrinos to Gran Sasso (CNGS) decay tube, in which particles produced in the collision with a proton and a graphite target will decay into muons and muon neutrinos. Four highly skilled welders performed this delicate task.

  19. A malfunctioning nasogastric feeding tube

    Directory of Open Access Journals (Sweden)

    Emanuele Cereda

    2013-02-01

    Full Text Available A critical point of nasogastric feeding tube placement, potentially resulting in an unsafe and/or non-effective operation of the device, is the monitoring of its proper placement into the stomach. A properly obtained and interpreted radiograph is currently recommended to confirm placement. We reported the case of a 68-year-old demented woman referred for complicated dysphagia. A nasogastric tube was blindly inserted and its placement was confirmed by the radiologist. Enteral nutrition was initiated but the patient began to vomit immediately. After reviewing the radiograph it was understood that a gastric loop in the tube and its tip pointing upwards did not allow a safe infusion of the feeding formula. It is not enough having the radiologist reporting that a nasogastric feeding tube is placed in the stomach; the inclusion in the report of specific warnings on any potential cause of malfunctioning of the device should be considered. The presence of a gastric loop should be taken into account as a cause of potential malfunctioning.

  20. Dynamics Calculation of Travel Wave Tube

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    During the dynamics calculating of the travel tube, we must obtain the field map in the tube. The field map can be affected by not only the beam loading, but also the attenuation coefficient. The calculation of the attenuation coefficient

  1. When to change a tracheostomy tube.

    Science.gov (United States)

    White, Alexander C; Kher, Sucharita; O'Connor, Heidi H

    2010-08-01

    Knowing when to change a tracheostomy tube is important for optimal management of all patients with tracheostomy tubes. The first tracheostomy tube change, performed 1-2 weeks after placement, carries some risk and should be performed by a skilled operator in a safe environment. The risk associated with changing the tracheostomy tube then usually diminishes over time as the tracheo-cutaneous tract matures. A malpositioned tube can be a source of patient distress and patient-ventilator asynchrony, and is important to recognize and correct. Airway endoscopy can be helpful to ensure optimal positioning of a replacement tracheostomy tube. Some of the specialized tracheostomy tubes available on the market are discussed. There are few data available to guide the timing of routine tracheostomy tube changes. Some guidelines are suggested.

  2. Structure and growth thermodynamics of carbon tubes

    Institute of Scientific and Technical Information of China (English)

    李文治; 钱露茜; 钱生法; 周维亚; 王刚; 付春生; 赵日安; 解思深

    1996-01-01

    Carbon tubes were prepared by Ni (or Ti) catalytic pyrolysis of acetylene. The catalytic effect of nanometer nickel powders is related to the reduction temperature in H2 atmosphere. Nanometer nickel powders reduced at high temperature have a distinguished catalytic effect, and the yield of the carbon tubes is relatively high; but for the nickel powders reduced at low temperature, the yield of carbon tubes is low, and no tube can be formed. Carbon tubes can only be grown along the edges or on the tips of the Ni (or Ti) sheets reduced at about 770C. But if Ni (or Ti) sheets are etched in acid, at lot of carbon tubes with various forms can be formed on their surface. The structure and morphology of the carbon tubes is studied, and the growth thermodynamics for the straight, curved and helical carbon tubes are systematically investigated for the first time.

  3. The accessory fallopian tube: A rare anomaly

    Directory of Open Access Journals (Sweden)

    Kusum R Gandhi

    2012-01-01

    Full Text Available This paper presents a rare anatomical variation in the form of accessory fallopian tube on right side. The duplication of fallopian tube was observed in a 34-year-old female during routine undergraduate dissection in our department. Fallopian tube is the part of uterus that carries the ovum from the ovary to the uterus. Accessory fallopian tube is the congenital anomaly attached to the ampullary part of main tube. This accessory tube is common site of pyosalpinx, hydrosalpinx, cystic swelling and torsion. The ovum released by the ovary may also be captured by the blind accessory tube leading to infertility or ectopic pregnancy. Hence, all patients of infertility or pelvic inflammatory disease should be screened to rule out the presence of accessory fallopian tube and if encountered should be removed.

  4. [A tube retractor for cardiac surgery].

    Science.gov (United States)

    Ohkado, A; Shiikawa, A; Ishitoya, H; Murata, A

    2001-03-01

    A retractor exclusively used to retract the tubes in cardiac surgery which needs cardiopulmonary bypass was developed. The half-cylinder-shaped end, the lightly curved handle and the flat and triangular grip enable easy and effective grasp of the tubes. This new instrument facilitates operative procedures by effectively retracting the tubes which persistently obstruct the operative field, in such a case of placement of a retrograde cardioplegia tube via the right atrium.

  5. Roll-forming tubes to header plates

    Science.gov (United States)

    Kramer, K.

    1976-01-01

    Technique has been developed for attaching and sealing tubes to header plates using a unique roll-forming tool. Technique is useful for attaching small tubes which are difficult to roll into conventional grooves in header plate tube holes, and for attaching when welding, brazing, or soldering is not desirable.

  6. Feasibility of Upper Port Plug tube handling

    NARCIS (Netherlands)

    Koning, J.F.; Elzendoorn, B.S.Q.; Ronden, D.M.S.; Klinkhamer, J.F.F.; Biel, W.; Krasikov, Y.; Walker, C.I.

    2011-01-01

    Central, retractable tubes are proposed in several Upper Port Plugs (UPPs) designs for ITER, to enable fast exchange of specific components of diagnostics housed in these UPPs. This paper investigates into possible designs to enable the efficient handling of tubes. The feasibility of tube handling i

  7. Inclusive spectra of hadrons created by color tube fission; 1, Probability of tube fission

    CERN Document Server

    Gedalin, E V

    1997-01-01

    The probability of color tube fission that includes the tube surface small oscillation corrections is obtained with pre-exponential factor accuracy on the basis of previously constructed color tube model. Using these expressions the probability of the tube fission in $n$ point is obtained that is the basis for calculation of inclusive spectra of produced hadrons.

  8. Capillary imbibition in parallel tubes

    Science.gov (United States)

    McRae, Oliver; Ramakrishnan, T. S.; Bird, James

    2016-11-01

    In modeling porous media two distinct approaches can be employed; the sample can be examined holistically, using global variables such as porosity, or it can be treated as a network of capillaries connected in series to various intermediate reservoirs. In forced imbibition this series-based description is sufficient to characterize the flow, due to the presence of an externally maintained pressure difference. However, in spontaneous imbibition, flow is driven by an internal capillary pressure, making it unclear whether a series-based model is appropriate. In this talk, we show using numerical simulations the dynamics of spontaneous imbibition in concentrically arranged capillary tubes. This geometry allows both tubes access to a semi-infinite reservoir but with inlets in close enough proximity to allow for interference. We compare and contrast the results of our simulations with theory and previous experiments. Schlumberger-Doll Research.

  9. Microstructural degradation in compound tubes

    Energy Technology Data Exchange (ETDEWEB)

    Salonen, J.; Auerkari, P. [VTT Manufacturing Technology, Espoo (Finland)

    1996-12-31

    In order to quantify microstructural degradation at high temperatures, samples of SA 210 / AISI 304 L compound tube material were annealed in the temperature range 540-720 deg C for 1 to 1 000 hours. The hardness of the annealed material was measured and the micro structure of the samples was investigated with optical and scanning electron microscopy. Microstructural degradation was characterised by the carbide structure in the ferritic-pearlitic base material and by the depth of decarburised and carburised zones of the compound tube interface. The observed changes were quantified in terms of their time and temperature dependence and diffusion coefficients of the process. The results can be used in estimating the extent of thermal exposure of high-temperature components after long-term service or after incidences of overheating. (orig.) (4 refs.)

  10. Mechanical Instabilities of Biological Tubes

    CERN Document Server

    Hannezo, Edouard; Prost, Jacques; 10.1103/PhysRevLett.109.018101

    2012-01-01

    We study theoretically the shapes of biological tubes affected by various pathologies. When epithelial cells grow at an uncontrolled rate, the negative tension produced by their division provokes a buckling instability. Several shapes are investigated : varicose, enlarged, sinusoidal or sausage-like, all of which are found in pathologies of tracheal, renal tubes or arteries. The final shape depends crucially on the mechanical parameters of the tissues : Young modulus, wall-to-lumen ratio, homeostatic pressure. We argue that since tissues must be in quasistatic mechanical equilibrium, abnormal shapes convey information as to what causes the pathology. We calculate a phase diagram of tubular instabilities which could be a helpful guide for investigating the underlying genetic regulation.

  11. Flux tubes at Finite Temperature

    CERN Document Server

    Bicudo, Pedro; Cardoso, Marco

    2016-01-01

    We show the flux tubes produced by static quark-antiquark, quark-quark and quark-gluon charges at finite temperature. The sources are placed in the lattice with fundamental and adjoint Polyakov loops. We compute the square densities of the chromomagnetic and chromoelectric fields above and below the phase transition. Our results are gauge invariant and produced in pure gauge SU(3). The codes are written in CUDA and the computations are performed with GPUs.

  12. Film holder for radiographing tubing

    Science.gov (United States)

    Davis, Earl V.; Foster, Billy E.

    1976-01-01

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

  13. Gated SIT Vidicon Streak Tube

    Science.gov (United States)

    Dunbar, D. L.; Yates, G. J.; Black, J. P.

    1986-01-01

    A recently developed prototype streak tube designed to produce high gain and resolution by incorporating the streak and readout functions in one envelope thereby minimizing photon-to-charge transformations and eliminating external coupling losses is presented. The tube is based upon a grid-gated Silicon-Intensified-Target Vidicon (SITV) with integral Focus Projection Scan (FPS) TV readout. Demagnifying electron optics (m=0.63) in the image section map the 40-mm-diameter photocathode image unto a 25-mm-diameter silicon target where gains >= 103 are achieved with only 10 KV accelerating voltage. This is compared with much lower gains (~ 50) at much higher voltages (~ 30 KV) reported for streak tubes using phosphor screens. Because SIT technology is well established means for electron imaging in vacuum, such fundamental problems as "backside thinning" required for electron imaging unto CCDs do not exist. The high spatial resolution (~ 30 1p/mm), variable scan formats, and high speed electrostatic deflection (250 mm2 areas are routinely rastered with 256 scan lines in 1.6 ms) available from FPS readout add versatility not available in CCD devices. Theoretical gain and spatial resolution for this design (developed jointly by Los Alamos National Laboratory and General Electric Co.) are compared with similar calculations and measured data obtained for RCA 73435 streaks fiber optically coupled to (1) 25-mm-diameter SIT FPS vidicons and (2) 40-mm-diameter MCPTs (proximity-focused microchannel plate image intensifier tubes) fiber optically coupled to 18-mm-diameter Sb2S3 FPS vidicons. Sweep sensitivity, shutter ratio, and record lengths for nanosecond duration (20 to 200 ns) streak applications are discussed.

  14. Aerodynamic drag from two tubes in side-by-side arrangement for different tube shapes

    Directory of Open Access Journals (Sweden)

    Олександр Михайлович Терех

    2016-06-01

    Full Text Available Experimental investigations of aerodynamic drag from two tubes in side-by-side arrangement for different tube shapes in the range of Reynolds numbers from 4000 to16000 are performed. Comparison of experimental data is executed. It is set, that the tubes of drop-shaped form have less aerodynamic drag and the tubes of flat-oval and dumb-bell forms have greater drag as compared to drag of circular tubes

  15. Preparation of chitosan nanofiber tube by electrospinning.

    Science.gov (United States)

    Matsuda, Atsushi; Kagata, Go; Kino, Rikako; Tanaka, Junzo

    2007-03-01

    Water-insoluble chitosan nanofiber sheets and tubes coated with chitosan-cast film were prepared by electrospinning. When as-spun chitosan nanofiber sheets and tubes were immersed in 28% ammonium aqueous solution, they became insoluble in water and showed nanofiber structures confirmed by SEM micrography. Mechanical properties of chitosan nanofiber sheets and tubes were improved by coating with chitosan-cast film, which gave them a compressive strength higher than that of crab-tendon chitosan, demonstrating that chitosan nanofiber tubes coated with chitosan-cast film are usable as nerve-regenerative guide tubes.

  16. Useful Scaling Parameters for the Pulse Tube

    Science.gov (United States)

    Lee, J. M.; Kittel, P.; Timmerhaus, K. D.; Radebaugh, R.; Cheng, Pearl L. (Technical Monitor)

    1995-01-01

    A set of eight non-dimensional scaling parameters for use in evaluating the performance of Pulse Tube Refrigerators is presented. The parameters result after scaling the mass, momentum and energy conservation equations for an axisymmetric, two-dimensional system. The physical interpretation of the parameters are described, and their usefulness is outlined for the enthalpy flow tube (open tube of the pulse tube). The scaling parameters allow the experimentalist to characterize three types of transport: enthalpy flow, mass streaming and heat transfer between the gas and the tube. Also reported are the results from a flow visualization experiment in which steady mass streaming in compressible oscillating flow is observed.

  17. Freezing in a vertical tube

    Energy Technology Data Exchange (ETDEWEB)

    Sparrow, E.M.; Broadbent, J.A.

    1983-05-01

    Fundamental heat transfer experiments were performed for freezing of an initially superheated or nonsuperheated liquid in a cooled vertical tube. Measurements were made which yielded information about the freezing front and the frozen mass, about the various energy components extracted from the tube, and about the decay of the initial liquid superheat. Four component energies were identified and evaluated from the experimental data, including the latent energy released by the phase change and sensibly energies released from the subcooled frozen solid and the superheated liquid. Initial superheating of the liquid tended to moderately diminish the frozen mass and latent energy extraction at short freezing times but had little effect on these quantitites at longer times. The extracted sensible energies associated with the superheating more than compensated for the aforementioned decrease in the latent energy. Although the latent energy is the largest contributor to the total extracted energy, the aggregate sensible energies can make a significant contribution, especially at large tube wall subcooling, large initial liquid superheating, and short freezing time. Natural convection effects in the superheated liquid were modest and were confined to short freezing times.

  18. Pump element for a tube pump

    DEFF Research Database (Denmark)

    2011-01-01

    The invention relates to a tube pump comprising a tube and a pump element inserted in the tube, where the pump element comprises a rod element and a first and a second non-return valve member positioned a distance apart on the rod element. The valve members are oriented in the same direction rela...... to a part of the tube. The invention further relates to a method for creating a flow of a fluid within an at least partly flexible tube by means of a pump element as mentioned above.......The invention relates to a tube pump comprising a tube and a pump element inserted in the tube, where the pump element comprises a rod element and a first and a second non-return valve member positioned a distance apart on the rod element. The valve members are oriented in the same direction...... portion acts to alternately close and open the valve members thereby generating a fluid flow through the tube. The invention further relates to a pump element comprising at least two non-return valve members connected by a rod element, and for insertion in an at least partly flexible tube in such tube...

  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. Development boiling to sprinkled tube bundle

    Directory of Open Access Journals (Sweden)

    Kracík Petr

    2016-01-01

    Full Text Available This paper presents results of a studied heat transfer coefficient at the surface of a sprinkled tube bundle where boiling occurs. Research in the area of sprinkled exchangers can be divided into two major parts. The first part is research on heat transfer and determination of the heat transfer coefficient at sprinkled tube bundles for various liquids, whether boiling or not. The second part is testing of sprinkle modes for various tube diameters, tube pitches and tube materials and determination of individual modes’ interface. All results published so far for water as the falling film liquid apply to one to three tubes for which the mentioned relations studied are determined in rigid laboratory conditions defined strictly in advance. The sprinkled tubes were not viewed from the operational perspective where there are more tubes and various modes may occur in different parts with various heat transfer values. The article focuses on these processes. The tube is located in a low-pressure chamber where vacuum is generated using an exhauster via ejector. The tube consists of smooth copper tubes of 12 mm diameter placed horizontally one above another.

  2. Development boiling to sprinkled tube bundle

    Science.gov (United States)

    Kracík, Petr; Pospíšil, Jiří

    2016-03-01

    This paper presents results of a studied heat transfer coefficient at the surface of a sprinkled tube bundle where boiling occurs. Research in the area of sprinkled exchangers can be divided into two major parts. The first part is research on heat transfer and determination of the heat transfer coefficient at sprinkled tube bundles for various liquids, whether boiling or not. The second part is testing of sprinkle modes for various tube diameters, tube pitches and tube materials and determination of individual modes' interface. All results published so far for water as the falling film liquid apply to one to three tubes for which the mentioned relations studied are determined in rigid laboratory conditions defined strictly in advance. The sprinkled tubes were not viewed from the operational perspective where there are more tubes and various modes may occur in different parts with various heat transfer values. The article focuses on these processes. The tube is located in a low-pressure chamber where vacuum is generated using an exhauster via ejector. The tube consists of smooth copper tubes of 12 mm diameter placed horizontally one above another.

  3. CT and radiographic assessment of tube thoracostomy

    Energy Technology Data Exchange (ETDEWEB)

    Stark, D.D.; Federle, M.P.; Goodman, P.C.

    1983-08-01

    Conventional chest radiography and computed tomography (CT) were used to evaluate tube thoracostomy drainage of pleural empyema in 26 selected patients. Frontal radiographs alone were inadequate in the evaluation of thoracostomy tube placement, as only one of 21 malpositioned tubes was identified; however, when lateral radiographs were also obtained, eight of nine malpositioned tubes were identified. Suboptimal drainage due to malpositioning was demonstrated best by CT in all 21 cases. Prolongation of hospitalization, serious complications, and death correlated with failure of early tube thoracostomy drainage as demonstrated by CT. Routine frontal and lateral chest radiographs are recommended for all patients after thoracostomy tube placement for empyema. For selected patients with empyema, early use of CT to guide tube repositioning or thoracotomy may reduce morbidity and mortality and decrease hospital costs.

  4. Tube erosion in bubbling fluidized beds

    Energy Technology Data Exchange (ETDEWEB)

    Levy, E.K. [Lehigh Univ., Bethlehem, PA (United States). Energy Research Center; Stallings, J.W. [Electric Power Research Inst., Palo Alto, CA (United States)

    1991-12-31

    This paper reports on experimental and theoretical studies that were preformed of the interaction between bubbles and tubes and tube erosion in fluidized beds. The results are applicable to the erosion of horizontal tubes in the bottom row of a tube bundle in a bubbling bed. Cold model experimental data show that erosion is caused by the impact of bubble wakes on the tubes, with the rate of erosion increasing with the velocity of wake impact with the particle size. Wake impacts resulting from the vertical coalescence of pairs of bubbles directly beneath the tube result in particularly high rates of erosion damage. Theoretical results from a computer simulation of bubbling and erosion show very strong effects of the bed geometry and bubbling conditions on computed rates of erosion. These results show, for example, that the rate of erosion can be very sensitive to the vertical location of the bottom row of tubes with respect to the distributor.

  5. Pulse tube cooler having 1/4 wavelength resonator tube instead of reservoir

    Science.gov (United States)

    Gedeon, David R. (Inventor)

    2008-01-01

    An improved pulse tube cooler having a resonator tube connected in place of a compliance volume or reservoir. The resonator tube has a length substantially equal to an integer multiple of 1/4 wavelength of an acoustic wave in the working gas within the resonator tube at its operating frequency, temperature and pressure. Preferably, the resonator tube is formed integrally with the inertance tube as a single, integral tube with a length approximately 1/2 of that wavelength. Also preferably, the integral tube is spaced outwardly from and coiled around the connection of the regenerator to the pulse tube at a cold region of the cooler and the turns of the coil are thermally bonded together to improve heat conduction through the coil.

  6. Effect of tube-support interaction on the dynamic responses of heat exchanger tubes. [LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Y.S.; Jendrzejczyk, J.A.; Wambsganss, M.W.

    1977-01-01

    Operating heat exchangers have experienced tube damages due to excessive flow-induced vibration. The relatively small inherent tube-to-baffle hole clearances associated with manufacturing tolerances in heat exchangers affect the tube vibrational characteristics. In attempting a theoretical analysis, questions arise as to the effects of tube-baffle impacting on dynamic responses. Experiments were performed to determine the effects of tube-baffle impacting in vertical/horizontal tube orientation, and in air/water medium on the vibrational characteristics (resonant frequencies, mode shapes, and damping) and displacement response amplitudes of a seven-span tube model. The tube and support conditions were prototypic, and overall length approximately one-third that of a straight tube segment of the steam generator designed for the CRBR. The test results were compared with the analytical results based on the multispan beam with ''knife-edge'' supports.

  7. Improved Traveling-Wave Tube

    Science.gov (United States)

    Rousseau, Art; Tammaru, Ivo; Vaszari, John

    1988-01-01

    New space traveling-wave tube (TWT) provides coherent source of 75 watts of continuous-wave power output over bandwidth of 5 GHz at frequency of 65 GHz. Coupled-cavity TWT provides 50 dB of saturated gain. Includes thermionic emitter, M-type dispenser cathode providing high-power electron beam. Beam focused by permanent magnets through center of radio-frequency cavity structure. Designed for reliable operation for 10 years, and overall efficiency of 35 percent minimizes prime power input and dissipation of heat.

  8. Counter-driver shock tube

    Science.gov (United States)

    Tamba, T.; Nguyen, T. M.; Takeya, K.; Harasaki, T.; Iwakawa, A.; Sasoh, A.

    2015-11-01

    A "counter-driver" shock tube was developed. In this device, two counter drivers are actuated with an appropriate delay time to generate the interaction between a shock wave and a flow in the opposite direction which is induced by another shock wave. The conditions for the counter drivers can be set independently. Each driver is activated by a separate electrically controlled diaphragm rupture device, in which a pneumatic piston drives a rupture needle with a temporal jitter of better than 1.1 ms. Operation demonstrations were conducted to evaluate the practical performance.

  9. Closed End Launch Tube (CELT)

    Science.gov (United States)

    Lueck, Dale E.; Immer, Christopher D.

    2004-02-01

    A small-scale test apparatus has been built and tested for the CELT pneumatic launch assist concept presented at STAIF 2001. The 7.5 cm (3-inch) diameter × 305 M (1000 feet) long system accelerates and pneumatically brakes a 6.35 cm diameter projectile with variable weight (1.5 - 5 Kg). The acceleration and braking tube has been instrumented with optical sensors and pressure transducers at 14 stations to take data throughout the runs. Velocity and pressure profiles for runs with various accelerator pressures and projectile weights are given. This test apparatus can serve as an important experimental tool for verifying this concept.

  10. CFD Simulation on Ethylene Furnace Reactor Tubes

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Different mathematical models for ethylene furnace reactor tubes were reviewed. On the basis of these models a new mathematical simulation approach for reactor tubes based on computational fluid dynamics (CFD) technique was presented. This approach took the flow, heat transfer, mass transfer and thermal cracking reactions in the reactor tubes into consideration. The coupled reactor model was solved with the SIMPLE algorithm. Some detailed information about the flow field, temperature field and concentration distribution in the reactor tubes was obtained, revealing the basic characteristics of the hydrodynamic phenomena and reaction behavior in the reactor tubes. The CFD approach provides the necessary information for conclusive decisions regarding the production optimization, the design and improvement of reactor tubes, and the new techniques implementation.

  11. Successful tubes treatment of esophageal fistula.

    Science.gov (United States)

    Zhou, Ning; Chen, Wei-xing; Li, You-ming; Xiang, Zhun; Gao, Ping; Fang, Ying

    2007-10-01

    To discuss the merits of "tubes treatment" for esophageal fistula (EF). A 66-year-old female who suffered from a bronchoesophageal and esophagothoratic fistula underwent a successful "three tubes treatment" (close chest drainage, negative pressure suction at the leak, and nasojejunal feeding tube), combination of antibiotics, antacid drugs and nutritional support. Another 55-year-old male patient developed an esophagopleural fistula (EPF) after esophageal carcinoma operation. He too was treated conservatively with the three tubes strategy as mentioned above towards a favorable outcome. The two patients recovered with the tubes treatment, felt well and became able to eat and drink, presenting no complaint. Tubes treatment is an effective basic way for EF. It may be an alternative treatment option.

  12. Successful tubes treatment of esophageal fistula

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Aim: To discuss the merits of "tubes treatment" for esophageal fistula (EF). Methods: A 66-year-old female who suffered from a bronchoesophageal and esophagothoratic fistula underwent a successful "three tubes treatment" (close chest drainage, negative pressure suction at the leak, and nasojejunal feeding tube), combination of antibiotics, antacid drugs and nutritional support. Another 55-year-old male patient developed an esophagopleural fistula (EPF) after esophageal carcinoma operation. He too was treated conservatively with the three tubes strategy as mentioned above towards a favorable outcome. Results:The two patients recovered with the tubes treatment, felt well and became able to eat and drink, presenting no complaint. Conclusion: Tubes treatment is an effective basic way for EF. It may be an alternative treatment option.

  13. Narratives From YouTube

    Directory of Open Access Journals (Sweden)

    Mikael Quennerstedt

    2013-10-01

    Full Text Available The aim of this paper is to explore what is performed in students’ and teachers’ actions in physical education practice in terms of “didactic irritations,” through an analysis of YouTube clips from 285 PE lessons from 27 different countries. Didactic irritations are occurrences that Rønholt describes as those demanding “didactic, pedagogical reflections and discussions, which in turn could lead to alternative thinking and understanding about teaching and learning.” Drawing on Barad’s ideas of performativity to challenge our habitual anthropocentric analytical gaze when looking at educational visual data, and using narrative construction, we also aim to give meaning to actions, relations, and experiences of the participants in the YouTube clips. To do this, we present juxtaposing narratives from teachers and students in terms of three “didactic irritations”: (a stories from a track, (b, stories from a game, and (c, stories from a bench. The stories re-present events-of-moving in the data offering insights into embodied experiences in PE practice, making students’ as well as teachers’ actions in PE practice understandable.

  14. Successful tubes treatment of esophageal fistula

    OpenAIRE

    Zhou, Ning; Chen, Wei-Xing; Li, You-ming; Xiang, Zhun; Gao, Ping; Fang, Ying

    2007-01-01

    Aim: To discuss the merits of “tubes treatment” for esophageal fistula (EF). Methods: A 66-year-old female who suffered from a bronchoesophageal and esophagothoratic fistula underwent a successful “three tubes treatment” (close chest drainage, negative pressure suction at the leak, and nasojejunal feeding tube), combination of antibiotics, antacid drugs and nutritional support. Another 55-year-old male patient developed an esophagopleural fistula (EPF) after esophageal carcinoma operation. He...

  15. Tube bending on the roll machine

    Science.gov (United States)

    Nepershin, Rostislav I.

    2013-10-01

    Computer simulation of the elastic-plastic tube bending by pushing on three-roll machine with work hardening effect consideration is presented. Non-steady tube bending process for specified curvature is simulated with axis of bending roll displacement, followed by transfer to the steady-state bending process. Estimation of curvature, constrained by tube section elliptical distortion modeled by plastic hinge mechanism is given. Elastic-plastic bending moment versus curvature and critical curvature estimation reasonably correlated with experiments.

  16. Literature search for ceramic vacuum tubes

    Energy Technology Data Exchange (ETDEWEB)

    Cannon, W.

    1977-01-12

    The NTIS and Engineering Index files were searched for citations relating to Ceramic and/or Metal Electron Tubes and High Temperature Electronics. A total of 24 citations were found relating directly to ceramic tubes and 24 to high temperature electronics. A search for electron tubes in general was examined for high temperature applications and 39 were obtained. Computer printouts of the abstracts are included in appendices. (MHR)

  17. Micro tube heat exchangers for Space Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Mezzo fabricates micro tube heat exchangers for a variety of applications, including aerospace, automotive racing, Department of Defense ground vehicles, economizers...

  18. Finned Small Diameter Tube Heat Exchanger

    Science.gov (United States)

    Dang, Chaobin; Daiguji, Hirofumi; Hihara, Eiji; Tokunaga, Masahide

    The performance of fined small tube heat exchangers was investigated both experimentally and theoretically. The Inner diameters of tubes were 1.0mm, 2.1mm and 4.0mm. Exchanged heat and pressure drop obtained from numerical simulation agreed well with the experimental ones. Calculation results show that the volume of a 2.0mm tube heat exchanger can be reduced to 33% of that of a 4mm tube heat exchanger with the same capacity. In addition the distribution of two-phase flow in a branching unit was investigated by measuring downstream temperature distribution. The flow distribution in a branching unit strongly affects the exchanged heat.

  19. GEIGER-MULLER TYPE COUNTER TUBE

    Science.gov (United States)

    Fowler, I.L.; Watt, L.A.K.

    1959-12-15

    A single counter tube capable of responding to a wide range of intensities is described. The counter tube comprises a tubular cathode and an anode extending centrally of the cathode. The spacing between the outer surface of the anode and the inner surface of the cathode is varied along the length of the tube to provide different counting volumes in adjacent portions of the tube. A large counting volume in one portion adjacent to a low-energy absorption window gives adequate sensitivity for measuring lowintensity radiation, while a smaller volume with close electrode spacing is provided in the counter to make possible measurement of intense garnma radiation fields.

  20. The nasogastric tube syndrome in infants.

    Science.gov (United States)

    Harmon, Jeffrey; Balakrishnan, Karthik; de Alarcon, Alessandro; Hart, Catherine K

    2014-05-01

    This series of three patients is the first description of the presentation, clinical course, and endoscopic findings of nasogastric tube-related airway distress, or nasogastric tube syndrome, in infants. We identify key differences in disease features from those described in adults, based on our literature review. Specifically, infant nasogastric tube syndrome presented as significant respiratory distress and postcricoid inflammation without vocal fold immobility. Symptoms resolved more quickly (mean±SD, 2±1 days) than reported in adults. We suggest that nasogastric tube syndrome should be considered in infants with otherwise unexplained respiratory distress, even in the absence of impaired vocal fold mobility.

  1. RF Breakdown in Drift Tube Linacs

    CERN Document Server

    Stovall, J; Lown, R

    2009-01-01

    The highest RF electric field in drift-tube linacs (DTLs) often occurs on the face of the first drift tube. Typically this drift tube contains a quadrupole focusing magnet whose fringing fields penetrate the face of the drift tube parallel to the RF electric fields in the accelerating gap. It has been shown that the threshold for RF breakdown in RF cavities may be reduced in the presence of a static magnetic field. This note offers a “rule of thumb” for picking the maximum “safe” surface electric field in DTLs based on these measurements.

  2. Cleaning device for inside of tube

    Energy Technology Data Exchange (ETDEWEB)

    Usuniwa, Yukio; Arai, Sanae; Koyama, Mayumi; Kuramata, Rumi

    1996-07-23

    A large number of small diameter tubes are disposed passing through a lower end plate of a main body of a reactor pressure vessel. The device of the present invention can wash the inside of the small diameter tube efficiently and forecast the completion time of the operation. Namely, purified water at a predetermined temperature is stored in a water reservoir of a purified water recycling unit. The purified water is introduced from a header to the inside of the tube by way of a short tube connected to the lower end of the tube. The purified water introduced into the tube is charged from an opening to an overflow tube and returned to the water reservoir passing through the over flowing tube. The inside of the tube is washed by such circulation of purified water. In the cleaning operation by using the device, (1) the completion time of the operation can be forecast and operationability is improved, and (2) since the operation can be performed rapidly, the period of time for performing the step can be shortened. (I.S.)

  3. Performance of multi tubes in tube helically coiled as a compact heat exchanger

    Science.gov (United States)

    Nada, S. A.; El Shaer, W. G.; Huzayyin, A. S.

    2014-12-01

    Multi tubes in tube helically coiled heat exchanger is proposed as a compact heat exchanger. Effects of heat exchanger geometric parameters and fluid flow parameters; namely number of inner tubes, annulus hydraulic diameter, Reynolds numbers and input heat flux, on performance of the heat exchanger are experimentally investigated. Different coils with different numbers of inner tubes, namely 1, 3, 4 and 5 tubes, were tested. Results showed that coils with 3 inner tubes have higher values of heat transfer coefficient and compactness parameter (bar{h} Ah ). Pressure drop increases with increasing both of Reynolds number and number of inner tubes. Correlations of average Nusselt number were deduced from experimental data in terms of Reynolds number, Prandtl number, Number of inner coils tubes and coil hydraulic diameter. Correlations prediction was compared with experimental data and the comparison was fair enough.

  4. Development and Technology Transfer of the Syncro Blue Tube (Gabriel) Magnetically GuidedFeeding Tube

    Science.gov (United States)

    2017-06-01

    pneumonias. Tube placement does not require costly fluroscopy or endoscopy. Any nurse who can place a nasogastric tube can place this feeding tube without...time required to secure FDA 510K 160787 clearance. FDA clearance was awarded August 9, 2016 for 510K160787 Table of Contents I. Introduction...small bowel feeding tube and developing a smaller version of the technology (8 Fr.). The basic design of the technology is to provide an easy and

  5. Fermilab drift tube Linac revisited

    Energy Technology Data Exchange (ETDEWEB)

    Milorad Popovic

    2004-05-12

    Using the PARMILA code running under PC-WINDOWS, the present performance of the Fermilab Drift Tube Linac has been analyzed in the light of new demands on the Linac/Booster complex (the Proton Source). The Fermilab Drift Tube Linac (DTL) was designed in the sixties as a proton linac with a final energy of 200 MeV and a peak current of 100mA. In the seventies, in order to enable multi-turn charge exchange injection into the Booster, the ion source was replaced by an H- source with a peak beam current of 25mA. Since then the peak beam current was steadily increased up to 55mA. In the early nineties, part of the drift tube structure was replaced with a side-coupled cavity structure in order to increase the final energy to 400 MeV. The original and still primary purpose of the linac is to serve as the injector for the Booster. As an added benefit, the Neutron Therapy Facility (NTF) was built in the middle seventies. It uses 66MeV protons from the Linac to produce neutrons for medical purposes. The Linac/Booster complex was designed to run at a fundamental cycling rate of 15Hz, but beam is accelerated on every cycle only when NTF is running. Until recently the demand from the High Energy Physics program resulted in an average linac beam repetition rate of order 1 Hz. With the MiniBoone experiment and the NuMI program, the demands on the Proton Source have changed, with emphasis on higher beam repetition rates up to 7.5Hz. Historically the beam losses in the linac were small, localized at one spot, so activation was not an important issue. With higher beam rate, this has the potential to become the dominant issue. Until today all tuning in the linac and Proton Source was governed by two goals: to maximize the peak beam current out of the linac and to minimize the beam losses in the linac. If maximal peak current from the linac is no longer a primary goal, then the linac quadrupoles can be adjusted differently to achieve different goals.

  6. 49 CFR 230.61 - Arch tubes, water bar tubes, circulators and thermic siphons.

    Science.gov (United States)

    2010-10-01

    ... (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND 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...

  7. A secure method of nasal endotracheal tube stabilization with suture and rubber tube.

    Science.gov (United States)

    Ota, Y; Karakida, K; Aoki, T; Yamazaki, H; Arai, I; Mori, Y; Nakatogawa, N; Suzuki, T

    2001-12-01

    A new method of stabilizing the nasal endotrascheal tube was described. The tube was secured to the anterior portion of the nasal septum with braided silk thread, which was tightened over the rubber tube to keep air route of the cuff open. There found no complications such as unplanned extubation, necrosis and infections of the nasal septum.

  8. 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

  9. 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.

  10. Photomultiplier Tubes at Cryogenic Temperatures

    Science.gov (United States)

    Saunders, Nathan

    2016-09-01

    Liquid noble gas scintillators are widely used in experiments searching for physics beyond the Standard Model. Photomultiplier Tubes (PMTs) working at cryogenic temperatures have been developed as the primary light readout device in those experiments. Three PMTs from Hamamatsu Photonics K.K. (R6041, R11065, and R8520) have been systematically characterized at liquid nitrogen temperature. The high voltage dividing circuits for two of the PMTs were custom-built to make sure there is similar performance at both room and liquid nitrogen temperatures. Their dark count rates at both temperatures were measured. Also measured were their single photoelectron responses at both temperatures using 300, 340, 370, and 420 nm LEDs. The intention is to couple these PMTs directly with inorganic scintillators at liquid nitrogen temperature to achieve high light yeilds for rare-event searches.

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

    Science.gov (United States)

    The construction of economical x-ray tube based irradiators in a variety of configurations is described using 1000 Watt x-ray tubes. Single tube, double tube, and four tube designs are described, as well as various cabinet construction techniques. Relatively high dose rates were achieved for small s...

  12. Teaching Shakespeare with YouTube

    Science.gov (United States)

    Desmet, Christy

    2009-01-01

    YouTube, the video sharing website that allows viewers to upload video content ranging from cute dog tricks to rare rock videos, also supports a lively community devoted to the performance of Shakespeare and Shakespearean adaptations. YouTube is also a popular site for student producers of Shakespeare performances, parodies, and other artistic…

  13. Arrangement of burner with sheath tube

    Energy Technology Data Exchange (ETDEWEB)

    Graat, J.W.; Remie, H.T.; Verhagen, A.M.

    1980-10-02

    This is concerned with an addition to the burner described in patent 28 28 319 in which fluid pulverised fuel and air is burnt in a chamber. The additional patent concerns a sheath tube, which surrounds the chamber and conducts the burnt gases on. The sheath tube has openings for better guidance of the thermal flow.

  14. A Flue Gas Tube for Thermoelectric Generator

    DEFF Research Database (Denmark)

    2013-01-01

    The invention relates to a flue gas tube (FGT) (1) for generation of thermoelectric power having thermoelectric elements (8) that are integrated in the tube. The FTG may be used in combined heat and power (CHP) system (13) to produce directly electricity from waste heat from, e.g. a biomass boiler...

  15. Fibreoptic Bronchoscope for Nasogastric Tube Placement

    OpenAIRE

    Bhandari Dhiraj; Garg Deepika; Chandankhede Shweta; Sharma Vaijyanti; Premendran Benhur; Tidke Sucheta

    2015-01-01

    A patient of stage III squamous cell carcinoma of mandible with hemi-mandibulectomy, modified radical neck dissection and radiotherapy required Ryle’s Tube (RT) insertion for feeding. This case report describes use of fibreoptic bronchoscope to place an endotracheal tube in oesophagus through nasal route which was then used as a conduit to pass a RT into stomach.

  16. Coupled-cavity traveling-wave tubes

    Science.gov (United States)

    Connolly, D. J.; Omalley, T. A.

    1980-01-01

    Computer program is developed for analysis of coupled cavity traveling waves tubes (TWT's) which are used in variety of radar and communications applications. Programmers can simulate tubes of arbitrary complexity such as input and output couplers and other features peculiar to one or few cavities which may be modeled by correct choices of input data.

  17. Confined Tube Crimp Using Portable Hand Tools

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, Joseph James [Los Alamos National Laboratory; Pereyra, R. A. [LANL Retired; Archuleta, Jeffrey Christopher [Los Alamos National Laboratory; Martinez, Isaac P. [Los Alamos National Laboratory; Nelson, A. M. [MST-16 Summer Student (2007); Allen, Ronald Scott [Los Alamos National Laboratory; Page, R. L. [LANL Retired; Freer, Jerry Eugene [Los Alamos National Laboratory; Dozhier, Nathan Gus [Los Alamos National Laboratory

    2016-04-04

    The Lawrence Radiation Laboratory developed handheld tools that crimp a 1/16 inch OD tube, forming a leak tight seal1 (see Figure 1). The leak tight seal forms by confining the 1/16 inch OD tubing inside a die while applying crimp pressure. Under confined pressure, the tube walls weld at the crimp. The purpose of this study was to determine conditions for fabricating a leak tight tube weld. The equipment was used on a trial-and-error basis, changing the conditions after each attempt until successful welds were fabricated. To better confine the tube, the die faces were polished. Polishing removed a few thousandths of an inch from the die face, resulting in a tighter grip on the tubing wall. Using detergent in an ultrasonic bath, the tubing was cleaned. Also, the time under crimp pressure was increased to 30 seconds. With these modifications, acceptable cold welds were fabricated. After setting the conditions for an acceptable cold weld, the tube was TIG welded across the crimped face.

  18. Broadcast yourself on YouTube - really?

    NARCIS (Netherlands)

    Kruitbosch, G.; Nack, F.

    2008-01-01

    One essential reason for people to publish on the web is to express themselves freely. YouTube facilitates this self-expression by allowing users to upload video content they generated. This paper investigates to what extent the videos on YouTube are self-generated content, instead of amalgamated

  19. Fibreoptic Bronchoscope for Nasogastric Tube Placement

    Directory of Open Access Journals (Sweden)

    Bhandari Dhiraj

    2015-09-01

    Full Text Available A patient of stage III squamous cell carcinoma of mandible with hemi-mandibulectomy, modified radical neck dissection and radiotherapy required Ryle’s Tube (RT insertion for feeding. This case report describes use of fibreoptic bronchoscope to place an endotracheal tube in oesophagus through nasal route which was then used as a conduit to pass a RT into stomach.

  20. Optimizing the Thermoacoustic Pulse Tube Refrigerator Performances

    Directory of Open Access Journals (Sweden)

    E. V. Blagin

    2014-01-01

    Full Text Available The article deals with research and optimization of the thermoacoustic pulse tube refrigerator to reach a cryogenic temperature level. The refrigerator is considered as a thermoacoustic converter based on the modified Stirling cycle with helium working fluid. A sound pressure generator runs as a compressor. Plant model comprises an inner heat exchanger, a regenerative heat exchanger, a pulse tube, hot and cold heat exchangers at its ends, an inertial tube with the throttle, and a reservoir. A model to calculate the pulse tube thermoacoustic refrigerator using the DeltaEC software package has been developed to be a basis for calculation techniques of the pulse tube refrigerator. Momentum, continuity, and energy equations for helium refrigerant are solved according to calculation algorithm taking into account the porosity of regenerator and heat exchangers. Optimization of the main geometric parameters resulted in decreasing temperature of cold heat exchanger by 41,7 K. After optimization this value became equal to 115,01 K. The following parameters have been optimized: diameters of the feeding and pulse tube and heat exchangers, regenerator, lengths of the regenerator and pulse and inertial tubes, as well as initial pressure. Besides, global minimum of temperatures has been searched at a point of local minima corresponding to the optimal values of abovementioned parameters. A global-local minima difference is 0,1%. Optimized geometric and working parameters of the thermoacoustic pulse tube refrigerator are presented.

  1. Places to Go: YouTube

    Science.gov (United States)

    Downes, Stephen

    2008-01-01

    Founded in 2005 by three former PayPal employees, YouTube has revolutionized the Internet, marking a change from the static Internet to the dynamic Internet. In this edition of Places to Go, Stephen Downes discusses how the rise of a ubiquitous media format--Flash video--has made YouTube's success possible and argues that Flash video has important…

  2. Sampling Artifacts from Conductive Silicone Tubing

    Energy Technology Data Exchange (ETDEWEB)

    Timko, Michael T.; Yu, Zhenhong; Kroll, Jesse; Jayne, John T.; Worsnop, Douglas R.; Miake-Lye, Richard C.; Onasch, Timothy B.; Liscinsky, David; Kirchstetter, Thomas W.; Destaillats, Hugo; Holder, Amara L.; Smith, Jared D.; Wilson, Kevin R.

    2009-05-15

    We report evidence that carbon impregnated conductive silicone tubing used in aerosol sampling systems can introduce two types of experimental artifacts: 1) silicon tubing dynamically absorbs carbon dioxide gas, requiring greater than 5 minutes to reach equilibrium and 2) silicone tubing emits organic contaminants containing siloxane that adsorb onto particles traveling through it and onto downstream quartz fiber filters. The consequence can be substantial for engine exhaust measurements as both artifacts directly impact calculations of particulate mass-based emission indices. The emission of contaminants from the silicone tubing can result in overestimation of organic particle mass concentrations based on real-time aerosol mass spectrometry and the off-line thermal analysis of quartz filters. The adsorption of siloxane contaminants can affect the surface properties of aerosol particles; we observed a marked reduction in the water-affinity of soot particles passed through conductive silicone tubing. These combined observations suggest that the silicone tubing artifacts may have wide consequence for the aerosol community and should, therefore, be used with caution. Gentle heating, physical and chemical properties of the particle carriers, exposure to solvents, and tubing age may influence siloxane uptake. The amount of contamination is expected to increase as the tubing surface area increases and as the particle surface area increases. The effect is observed at ambient temperature and enhanced by mild heating (<100 oC). Further evaluation is warranted.

  3. Broadcast yourself on YouTube - really?

    NARCIS (Netherlands)

    Kruitbosch, G.; Nack, F.

    2008-01-01

    One essential reason for people to publish on the web is to express themselves freely. YouTube facilitates this self-expression by allowing users to upload video content they generated. This paper investigates to what extent the videos on YouTube are self-generated content, instead of amalgamated co

  4. Arrested segregative phase separation in capillary tubes

    NARCIS (Netherlands)

    Tromp, R. Hans; Lindhoud, Saskia

    2006-01-01

    Phase separation in a capillary tube with one of the phases fully wetting the capillary wall is arrested when the typical size of the phase domains reaches the value of the diameter of the tube. The arrested state consists of an alternating sequence of concave-capped and convex-capped cylindrical

  5. Repairing Hidden Cracks in Coolant Tubes

    Science.gov (United States)

    Mills, R. C., Sr.; Duesberg, J.

    1984-01-01

    Repair technique closes leaks in tubes or conduits where access limited to wall opposite crack. Technique applicable to any tubular assembly where tubes bundled together or bonded to supporting shell, such as in heat exchangers. Procedure provides structural support to area failed and uninterrupted flow without significantly altering heat-transfer profile.

  6. Tube-bending scale/protractor

    Science.gov (United States)

    Millett, A. U.

    1977-01-01

    Combination protractor and scale for measuring tube bends has novel pivot that allows tube to remain in contact with scale arms for all bend angles. Device permits rapid and accurate scribing and measurement of mockup fluid lines to obtain production data.

  7. Sound absorption and reflection with coupled tubes

    NARCIS (Netherlands)

    Eerden, van der Frits

    2000-01-01

    This paper describes a special sound absorbing technique with an accompanying efficient numerical design tool. As a basis pressure waves in a single narrow tube or pore are considered. In such a tube the viscosity and the thermal conductivity of the air, or any other fluid, can have a significant ef

  8. Metal hydrides studied in gas discharge tube

    Science.gov (United States)

    Bozhinova, I.; Kolev, S.; Popov, Tsv.; Pashov, A.; Dimitrova, M.

    2016-05-01

    A novel construction of gas discharge tube has been tested for production of high densities of metal hydrydes. Its performance turned out to be comparable with the existing sources of the same type and even better. First results of the tests on NiH are reported and critically analysed. Plans for future modifiaction of the construction and application of the tube are discussed.

  9. Tube formula, Berezinians, and Dwork formula

    CERN Document Server

    Khudaverdian, Hovhannes M

    2007-01-01

    We consider an example of tubes of hypersurfaces in Euclidean space and generalise the tube formula to supercase. By this we assign to a point of the hypersurface in superspace a rational characteristic function. Does this rational function appear when we calculate the zeta-function of an arithmetic variety?

  10. Development of Zirconium alloys (for pressure tubes)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Suk; Kwon, Sang Chul; Choo, Ki Nam; Jung, Chung Hwan; Yim, Kyong Soo; Kim, Sung Soo; Baek, Jong Hyuk; Jeong, Yong Hwan; Kim, Kyong Ho; Cho, Hae Dong [Korea Atomic Energy Research Inst., Daeduk (Korea, Republic of); Hwang, S. K.; Kim, M. H. [Inha Univ., Incheon (Korea, Republic of); Kwon, S. I [Korea Univ., Seoul (Korea, Republic of); Kim, I. S. [Korea Advanced Inst. of Science and Technology, Taejon (Korea, Republic of)

    1997-09-01

    The objective of this research is to set up the basic technologies for the evaluation of pressure tube integrity and to develop improved zirconium alloys to prevent pressure tube failures due to DHC and hydride blister caused by excessive creep-down of pressure tubes. The experimental procedure and facilities for characterization of pressure tubes were developed. The basic research related to a better understanding of the in-reactor performances of pressure tubes leads to noticeable findings for the first time : the microstructural effect on corrosion and hydrogen pick-up behavior of Zr-2.5Nb pressure tubes, texture effect on strength and DHC resistance and enhanced recrystallization by Fe in zirconium alloys and etc. Analytical methodology for the assessment of pressure tubes with surface flaws was set up. A joint research is being under way with AECL to determine the fracture toughness of O-8 at the EOL (End of Life) that had been quadruple melted and was taken out of the Wolsung Unit-1 after 10 year operation. In addition, pressure tube with texture controlled is being made along with VNINM in Russia as a joint project between KAERI and Russia. Finally, we succeeded in developing 4 different kinds of zirconium alloys with better corrosion resistance, low hydrogen pickup fraction and higher creep strength. (author). 121 refs., 65 tabs., 260 figs

  11. Teaching Shakespeare with YouTube

    Science.gov (United States)

    Desmet, Christy

    2009-01-01

    YouTube, the video sharing website that allows viewers to upload video content ranging from cute dog tricks to rare rock videos, also supports a lively community devoted to the performance of Shakespeare and Shakespearean adaptations. YouTube is also a popular site for student producers of Shakespeare performances, parodies, and other artistic…

  12. The Mashups of YouTube

    DEFF Research Database (Denmark)

    Simonsen, Thomas Mosebo

    2013-01-01

    This article focuses on YouTube mashups and how we can understand them as a specific subgenre on YouTube. The Mashups are analysed as audiovisual recontextualizations that are given new meaning, e.g., via collaborative social communities or for individual promotional purposes. This is elaborated......, but rather in its social and communicative abilities within the YouTube community. This leads to the article’s overall argument that the main characteristic of the YouTube Mashup can be explained in terms of connectivity. It is argued that Mashups reveal a double articulation of connectivity; one...... that involves the social mechanisms of the Mashups, and another mode, which concerns the explicit embedding of structural connectivity that accentuates the medium-specific infrastructure of YouTube. This double articulation of connectivity is furthermore elaborated on by including Grusin and Bolter’s concept...

  13. Ultra-fast framing camera tube

    Science.gov (United States)

    Kalibjian, Ralph

    1981-01-01

    An electronic framing camera tube features focal plane image dissection and synchronized restoration of the dissected electron line images to form two-dimensional framed images. Ultra-fast framing is performed by first streaking a two-dimensional electron image across a narrow slit, thereby dissecting the two-dimensional electron image into sequential electron line images. The dissected electron line images are then restored into a framed image by a restorer deflector operated synchronously with the dissector deflector. The number of framed images on the tube's viewing screen is equal to the number of dissecting slits in the tube. The distinguishing features of this ultra-fast framing camera tube are the focal plane dissecting slits, and the synchronously-operated restorer deflector which restores the dissected electron line images into a two-dimensional framed image. The framing camera tube can produce image frames having high spatial resolution of optical events in the sub-100 picosecond range.

  14. Turbulent flow in longitudinally finned tubes

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, D.P.; Hirsa, A.; Jensen, M.K. [Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Mechanical Engineering, Aeronautical Engineering and Mechanics

    1996-09-01

    An experimental investigation of fully developed, steady, turbulent flow in longitudinally finned tubes has been performed. A two-channel, four-beam, laser-Doppler velocimeter was used to measure velocity profiles and turbulent statistics of air flow seeded with titanium dioxide particles. Mean velocities in axial, radial, and circumferential directions were measured over the tube cross sections and pressure drop in the tubes was measured at six stations along the test section length in order to calculate the fully developed friction factor. Four experimental tube geometries were studied: one smooth tube; two 8-finned tubes (fin height-to-radius ratios of 0.333 and 0.167), and one 16-finned tube (fin height-to-radius ratio of 0.167); detailed measurements were taken at air flow rates corresponding to Reynolds numbers of approximately 5,000, 25,000, and 50,000. Friction factor data were compared to literature results and showed good agreement for both smooth and finned tubes. The wall shear stress distribution varied significantly with reynolds number, particularly for Reynolds numbers of 25,000 and below. Maximum wall shear stress was found at the fin tip and minimum at the fin root. Four secondary flow cells were detected per fin (one in each interfin spacing and one in each core region for each fin); secondary flows were found to be small in comparison to the mean axial flow and relative magnitudes were unaffected by axial flow rate at Reynolds numbers above 25,000. The fluctuating velocities had a structure similar to that of the smooth tube in the core region while the turbulence in the interfin region was greatly reduced. The principal, primary shear stress distribution differed considerably from that of the smooth tube, particularly in the interfin region, and the orientation was found to be approximately in the same direction as the gradient of the mean axial velocity, supporting the use of an eddy viscosity formulation in turbulence modeling.

  15. Cold Inertance Tube for 4 K Stirling Type Pulse Tube Cryocoolers

    Science.gov (United States)

    Li, ZhuoPei; Gan, ZhiHua; Qiu, LiMin

    The losses in the regenerator are minimized when the amplitude of the mass flow is minimized for a given acoustic power which requires that the mass flow lags the pressure by about 30° at the cold end of regenerator. The phase shift provided by an inertance tube is strongly influenced by the temperature of the inertance tube and the acoustic power at the cold end of the regenerator. For a 4 K Stirling type pulse tube cryocooler, the acoustic power at the cold end of the regenerator decreases significantly with the temperature thereby it's difficult to achieve ideal phase relationship with ambient inertance tube. While cold inertance tube provide a larger phase shift in that the viscosity of the working fluid decreases and the density increases as the temperature decreases. However, use of cold inertance tube increases additional heat load to the regenerator. Therefore it's of great significance to determine when a cold inertance tube should be used. In this paper effect of temperature of inertance tube is calculated for a 4 K Stirling type pulse tube cryocooler with different acoustic powers at the cold end. A comparison of ambient temperature inertance tube and cold inertance tube is made.

  16. Experimental study on in-tube condensation heat transfer characteristics of helically coiled spiral tubes

    Energy Technology Data Exchange (ETDEWEB)

    Park, J.U. [Sunchon First College, Sunchon (Korea); Kweon, Y.C. [Sun Moon University, Chonan (Korea); Han, K.I. [Pukyong National University, Pusan (Korea)

    2001-12-01

    An experimental study on condensation heat transfer characteristics of helically coiled spiral tubes was performed. The refrigerant is R-113. A refrigerant loop was established to measure the condensation heat transfer coefficients. Experiments were carried out uniform heat flux of 15 kW/m{sup 2}, refrigerant quality of 0.1 {approx} 0.9, curvature ratio of 0.016, 0.025 and 0.045. The curvature of a coil was defined as the ratio of the inside diameter of the tube to the diameter of the bending circle. To compare the condensation heat transfer coefficients of coiled spiral tubes, the previous results on coiled plain tubes and straight plain tubes were used. The results shows that the condensation heat transfer coefficients of coiled spiral tubes largely increase, as increasing Re and quality, compared to those of coiled plain tubes and straight plain tubes. As increasing degree of subcooling, however, the condensation heat transfer coefficients on coiled spiral tubes decrease. It is found that the heat transfer enhancement is more better than coiled plain tubes and straight plain tubes, as increasing curvature ratio. (author). 13 refs., 10 figs., 1 tab.

  17. Improve seawater cooling with titanium finned tubes

    Energy Technology Data Exchange (ETDEWEB)

    O' Donnell J. (High Performance Tube, Inc., Warren, NJ (United States))

    1992-10-01

    Seawater offers an endless supply of cooling water for these coastal processing facilities. But users must address seawater's corrosive nature in selecting construction materials for heat exchangers. Copper-nickel or carbon steel tubing fails continually under seawater service. This paper reports that titanium tubes, once thought to be too expensive a material for heat exchanger tubing, offer a unique combination of high material strength, excellent resistance to corrosion, and endurance to erosion by seawater. Titanium's superior physical properties in combination with enhanced surface area of low finned tubing perform the same heat duty with half the lineal footage of traditional heat exchanger tubes. High density low finned tubes multiply heat transfer capacity by a factor of two compared to plain tube. The technology applies in retrofit and original equipment manufacture (OEM) situations. It works best when the ratio of heat transfer coefficients is 2:1 or higher between the seawater coolant and shellside flow being cooled.

  18. Tube Thoracostomy: Complications and Its Management

    Science.gov (United States)

    Kesieme, Emeka B.; Dongo, Andrew; Ezemba, Ndubueze; Irekpita, Eshiobo; Jebbin, Nze; Kesieme, Chinenye

    2012-01-01

    Background. Tube thoracostomy is widely used throughout the medical, surgical, and critical care specialities. It is generally used to drain pleural collections either as elective or emergency. Complications resulting from tube thoracostomy can occasionally be life threatening. Aim. To present an update on the complications and management of complications of tube thoracostomy. Methods. A review of the publications obtained from Medline search, medical libraries, and Google on tube thoracostomy and its complications was done. Results. Tube thoracostomy is a common surgical procedure which can be performed by either the blunt dissection technique or the trocar technique. Complication rates are increased by the trocar technique. These complications have been broadly classified as either technical or infective. Technical causes include tube malposition, blocked drain, chest drain dislodgement, reexpansion pulmonary edema, subcutaneous emphysema, nerve injuries, cardiac and vascular injuries, oesophageal injuries, residual/postextubation pneumothorax, fistulae, tumor recurrence at insertion site, herniation through the site of thoracostomy, chylothorax, and cardiac dysrhythmias. Infective complications include empyema and surgical site infection. Conclusion. Tube thoracostomy, though commonly performed is not without risk. Blunt dissection technique has lower risk of complications and is hence recommended. PMID:22028963

  19. Applicable methods for NDT of tubes

    Energy Technology Data Exchange (ETDEWEB)

    Pitkaenen, J.; Lipponen, A.; Kauppinen, P. [VTT Industrial Systems Espoo (Finland)

    2004-05-01

    For inside inspection of tubes, eddy current testing (ET) and internal rotating ultrasonic inspection (IRIS) are mainly used at the moment. Special eddy current method, remote field technique (RFEC) is being used to some extent, but normally only for ferritic tubes. This paper presents a review of techniques that can be used for internal inspections of tubes in boilers, heat exchangers and steam generators. Material affects the choice of the method, considering given defect type and detectability with the selected technique. In general ET methods are used for inspection of non- ferromagnetic tubes and IRIS and RFEC methods for inspection of ferromagnetic tubes. New techniques have been introduced, to determine the tube condition accurately. One of the developed techniques is for instance inspection of the internal surface by combination of dye penetrant and optical laser inspection. New applications of ultrasonic techniques include defect detection and characterisation by tip diffraction echoes, defect analysis by echo dynamics and the TOFD-technique for defect sizing. Ultrasonic guided waves have a great potential to increase inspection speed for defect detection, although sizing is still under development. For inspection of ferromagnetic tubes, a method based on magnetic flux leakage has been used. In addition to the basic techniques visualisation of the measured data is one of the. key factors for improved exploitation of the inspection results. (orig.)

  20. Performance characteristics of pulse tube refrigerators

    Science.gov (United States)

    Huang, B. J.; Tzeng, T. M.

    In the present study experiments were carried out to investigate the performance characteristics of pulse tube refrigerators. It was found that the cool-down time tc during the transient or start-up period is dominated by the time constant of the pulse tube wall τpt and that the dynamics of a basic pulse tube (BPT) refrigerator approaches that of a first-order system. For steady state operation, the cold-end temperature TL was found to vary with τpt, and the cooling load QL increases monotonically with increasing τpt. This indicates that heat pumped by the gas from the cold to the hot end increases with decreasing hpt (i.e. less energy exchange between the gas and wall). The process of heat storage or release of the pulse tube wall is thus shown to have a negative effect on the performance of a BPT refrigerator. It was thus found experimentally that the gas compression/expansion process inside the pulse tube, which is similar to a Brayton cycle but lies between isothermal and adiabatic, can explain the performance of BPT refrigerators. The present experiment also shows that the performance of a pulse tube refrigerator at transient and steady states is mainly dominated by the time constant of the pulse tube wall τpt.

  1. Modelling Fluidelastic Instability Forces in Tube Arrays

    Science.gov (United States)

    Anderson, J. Burns

    Historically, heat exchangers have been among the most failure prone components in nuclear power plants. Most of these failures are due to tube failures as a result of corrosion, fatigue and fretting wear. Fatigue and fretting wear are a result of flow induced vibration through turbulent buffeting and fluidelastic instability mechanisms. Fluidelastic instability is by far the most important and complex mechanism. This research deals with modelling fluidelastic instability and the resulting tube response. The proposed time domain model uses the concept of a flow cell (Hassan & Hayder [16]) to represent the complex flow field inside a shell and tube heat exchanger and accounts for temporal variations in the flow separation points as a result of tube motion. The fluidelastic forces are determined by predicting the attachment lengths. The predicted forces are used to simulate the response of a single flexible tube inside a shell and tube heat exchanger. It was found that accounting for temporal variations in the separation points predicted lower critical flow velocities, than that of fixed attachment and separation points. Once unstable a phase lag is predicted between the fluidelastic forces and tube response. It was determined that the predicted critical flow velocities agreed well with available experimental data. The developed model represents an important step towards a realistic fluidelastic instability model which can be used to design the new generation nuclear steam generators.

  2. Friction Modeling in Concentric Tube Robots.

    Science.gov (United States)

    Lock, Jesse; Dupont, Pierre E

    2011-01-01

    Concentric tube robots are a novel class of continuum robots that are constructed by combining pre-curved elastic tubes such that the overall shape of the robot is a function of the relative rotations and translations of the constituent tubes. Frictionless kinematic and quasistatic force models for this class of robots have been developed that incorporate bending and twisting of the tubes. Experimental evaluation of these models has revealed, however, a directional dependence of tube rotation on robot shape that is not predicted by these models. To explain this behavior, this paper models the contributions of friction arising from two sources: the distributed forces of contact between the tubes along their length and the concentrated bending moments generated at discontinuities in curvature and at the boundaries. It is shown that while friction due to distributed forces is insufficient to explain the experimentally observed tube twisting, a simple model of frictional torque arising from concentrated moments provides a good match with the experimental data.

  3. Air flow exploration of abrasive feed tube

    Science.gov (United States)

    Zhang, Shijin; Li, Xiaohong; Gu, Yilei

    2009-12-01

    An abrasive water-jet cutting process is one in which water pressure is raised to a very high pressure and forced through a very small orifice to form a very thin high speed jet beam. This thin jet beam is then directed through a chamber and then fed into a secondary nozzle, or mixing tube. During this process, a vacuum is generated in the chamber, and garnet abrasives and air are pulled into the chamber, through an abrasive feed tube, and mixes with this high speed stream of water. Because of the restrictions introduced by the abrasive feed tube geometry, a vacuum gradient is generated along the tube. Although this phenomenon has been recognized and utilized as a way to monitor nozzle condition and abrasive flowing conditions, yet, until now, conditions inside the abrasive feed line have not been completely understood. A possible reason is that conditions inside the abrasive feed line are complicated. Not only compressible flow but also multi-phase, multi-component flow has been involved in inside of abrasive feed tube. This paper explored various aspects of the vacuum creation process in both the mixing chamber and the abrasive feed tube. Based on an experimental exploration, an analytical framework is presented to allow theoretical calculations of vacuum conditions in the abrasive feed tube.

  4. Investigating the Dynamics of Canonical Flux Tubes

    Science.gov (United States)

    von der Linden, Jens; Sears, Jason; Intrator, Thomas; You, Setthivoine

    2016-10-01

    Canonical flux tubes are flux tubes of the circulation of a species' canonical momentum. They provide a convenient generalization of magnetic flux tubes to regimes beyond magnetohydrodynamics (MHD). We hypothesize that hierarchies of instabilities which couple disparate scales could transfer magnetic pitch into helical flows and vice versa while conserving the total canonical helicity. This work first explores the possibility of a sausage instability existing on top of a kink as mechanism for coupling scales, then presents the evolution of canonical helicity in a gyrating kinked flux rope. Analytical and numerical stability spaces derived for magnetic flux tubes with core and skin currents indicate that, as a flux tube lengthens and collimates, it may become kink unstable with a sausage instability developing on top of the kink. A new analysis of 3D magnetic field and ion flow data on gyrating kinked magnetic flux ropes from the Reconnection Scaling Experiment tracks the evolution of canonical flux tubes and their helicity. These results and methodology are being developed as part of the Mochi experiment specifically designed to observe the dynamics of canonical flux tubes. This work is supported by DOE Grant DE-SC0010340 and the DOE Office of Science Graduate Student Research Program and prepared in part by LLNL under Contract DE-AC52-07NA27344. LLNL-ABS-697161.

  5. Vibrations of tube arrays in transversal flow

    Energy Technology Data Exchange (ETDEWEB)

    Gibert, R.J.; Villard, B. (C.E.N. Saclay, Gif-sur-Yvette (France)); Chabrerie, J. (Ste Fives-Cail-Babcok, La Courneuve, (France)); Sagner, V. (Ste Bertin, Plaisir (France))

    1981-01-01

    The vibrations induced in tube arrays by a transversal flow are of great practical interest because of their destructive effects especially on heat exchangers. Though turbulence can significantly excite the tubes by itself, most intense vibrations are still caused by two fluid-elastic phenomena: - The << lock-in >> effect: The basic phenomenon consists of a generation and a synchronization of vortex shedding by a transversal tube motion when its frequency approaches the shedding frequency and when its level is large enough. The so modified vortex shedding generates much more intense vibrations. The lock-in effects is well known for a single cylinder. Less results have been obtained for bundles. - The whirling instability: In a tube row or a bundle, quasi-steady forces are generated by the displacements of the tubes in the flow field. Adjacent tubes are disymmetrically coupled by these forces and instability can appear beyond a critical flow velocity. For the tube rows H.J. Connors has shown that the phenomena are characterized by a coefficient c (which is a function of the pitch).

  6. The structural stability of lunar lava tubes

    Science.gov (United States)

    Blair, David M.; Chappaz, Loic; Sood, Rohan; Milbury, Colleen; Bobet, Antonio; Melosh, H. Jay; Howell, Kathleen C.; Freed, Andrew M.

    2017-01-01

    Mounting evidence from the SELENE, LRO, and GRAIL spacecraft suggests the presence of vacant lava tubes under the surface of the Moon. GRAIL evidence, in particular, suggests that some may be more than a kilometer in width. Such large sublunarean structures would be of great benefit to future human exploration of the Moon, providing shelter from the harsh environment at the surface-but could empty lava tubes of this size be stable under lunar conditions? And what is the largest size at which they could remain structurally sound? We address these questions by creating elasto-plastic finite element models of lava tubes using the Abaqus modeling software and examining where there is local material failure in the tube's roof. We assess the strength of the rock body using the Geological Strength Index method with values appropriate to the Moon, assign it a basaltic density derived from a modern re-analysis of lunar samples, and assume a 3:1 width-to-height ratio for the lava tube. Our results show that the stability of a lava tube depends on its width, its roof thickness, and whether the rock comprising the structure begins in a lithostatic or Poisson stress state. With a roof 2 m thick, lava tubes a kilometer or more in width can remain stable, supporting inferences from GRAIL observations. The theoretical maximum size of a lunar lava tube depends on a variety of factors, but given sufficient burial depth (500 m) and an initial lithostatic stress state, our results show that lava tubes up to 5 km wide may be able to remain structurally stable.

  7. Experimental investigation of friction coefficient in tube hydroforming

    Institute of Scientific and Technical Information of China (English)

    Hyae Kyung YI; Hong Sup YIM; Gun Yeop LEE; Sung Mun LEE; Gi Suk CHUNG; Young-Hoon MOON

    2011-01-01

    The friction coefficient between tube and die in guide zone of tube hydroforming was obtained. In hydroforming, the tube is expanded by an internal pressure against the tool wall. By pushing the tube through tool, a friction force at the contact surface between the tube and the tool occurs. In guiding zone, the friction coefficients between tube and die can be estimated from the measured axial feeding forces. In expansion zone, the friction coefficients between tube and die can be evaluated from the measured geometries of expanded tubes and FE analysis.

  8. Tube Formation in Nanoscale Materials

    Directory of Open Access Journals (Sweden)

    Yan Chenglin

    2008-01-01

    Full Text Available Abstract The formation of tubular nanostructures normally requires layered, anisotropic, or pseudo-layered crystal structures, while inorganic compounds typically do not possess such structures, inorganic nanotubes thus have been a hot topic in the past decade. In this article, we review recent research activities on nanotubes fabrication and focus on three novel synthetic strategies for generating nanotubes from inorganic materials that do not have a layered structure. Specifically, thermal oxidation method based on gas–solid reaction to porous CuO nanotubes has been successfully established, semiconductor ZnS and Nb2O5nanotubes have been prepared by employing sacrificial template strategy based on liquid–solid reaction, and an in situ template method has been developed for the preparation of ZnO taper tubes through a chemical etching reaction. We have described the nanotube formation processes and illustrated the detailed key factors during their growth. The proposed mechanisms are presented for nanotube fabrication and the important pioneering studies are discussed on the rational design and fabrication of functional materials with tubular structures. It is the intention of this contribution to provide a brief account of these research activities.

  9. 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.

  10. Transport logistics in pollen tubes.

    Science.gov (United States)

    Chebli, Youssef; Kroeger, Jens; Geitmann, Anja

    2013-07-01

    Cellular organelles move within the cellular volume and the effect of the resulting drag forces on the liquid causes bulk movement in the cytosol. The movement of both organelles and cytosol leads to an overall motion pattern called cytoplasmic streaming or cyclosis. This streaming enables the active and passive transport of molecules and organelles between cellular compartments. Furthermore, the fusion and budding of vesicles with and from the plasma membrane (exo/endocytosis) allow for transport of material between the inside and the outside of the cell. In the pollen tube, cytoplasmic streaming and exo/endocytosis are very active and fulfill several different functions. In this review, we focus on the logistics of intracellular motion and transport processes as well as their biophysical underpinnings. We discuss various modeling attempts that have been performed to understand both long-distance shuttling and short-distance targeting of organelles. We show how the combination of mechanical and mathematical modeling with cell biological approaches has contributed to our understanding of intracellular transport logistics.

  11. Atmosphere in a Test Tube

    Science.gov (United States)

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

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

  12. Influence of furnace tube shapeon thermal strain of fire-tube boilers

    Directory of Open Access Journals (Sweden)

    Gaćeša Branka

    2014-01-01

    Full Text Available The aim of this paper is to use numerical analysis and fine element method-FEM to investigate the influence of furnace tube shape on the thermal strain of fire-tube boilers. Thermal stresses in corrugated furnace tubes of different shape, i.e. with different corrugation pitch and depth, were analysed first. It was demonstrated that the thermal stresses in corrugated furnace tube are significantly reduced with the increase of corrugation depth. Than deformations and stresses in the structure of a fire-tube boiler were analysed in a real operating condition, for the cases of installed plain furnace tube and corrugated furnace tubes with different shapes. It was concluded that in this fire-tube boiler, which is of larger steam capacity, the corrugated furnace tube must be installed, as well as that the maximal stress in the construction is reduced by the installation of the furnace tube with greater corrugation depth. The analysis of stresses due to pressure and thermal loads pointed out that thermal stresses are not lower-order stresses in comparison to stresses due to pressure loads, so they must be taken into consideration for boiler strength analysis. [Projekat Ministarstva nauke Republike Srbije, br. TR 35040 i br. TR 35011

  13. Enhancenment of In-tube Condensation of Nonazeotropic Refrigerant Mixtures with a Micro-fin Tube

    Science.gov (United States)

    Koyama, Shigeru; Gao, Lei; Hujii, Tetsu

    Condensation heat transfer and pressure drop characteristics of nonazeotropic refrigerant mixtures (NARMs) of HCFC22 and CFC114 inside horizontal smooth and micro-fin tubes are experimentally investigated. The local Nusselt number for both tubes based on the temperature difference between bulk refrigerant and tube wall is compared. Data for the micro-fin tube are about 50% higher than those for the smooth tube in both cases of pure refrigerants and NARMs. In case of NARMs, however, the decrease of Nesselt number due to vapor mass transfer resistance is observed for the micro-fin tube as well as for the smooth tube. By assuming that heat transfer characteristics of the condensate of NARMs are similar to those for pure refrigerants, the vapor mass transfer coefficient of NARMs is evaluated. Comparison of frictional pressure drop for both tubes is also performed in the Lockharte-Martinelli relation. Data for the micro-fin tube are higer than those for the smooth tube. The maximum increase of the frictional pressure drop is about 30%.

  14. Investigation of contact resistance for fin-tube heat exchanger by means of tube expansion

    Science.gov (United States)

    Hing, Yau Kar; Raghavan, Vijay R.; Meng, Chin Wai

    2012-06-01

    An experimental study on the heat transfer performance of a fin-tube heat exchanger due to mechanical expansion of the tube by bullets has been reported in this paper. The manufacture of a fin-tube heat exchanger commonly involves inserting copper tubes into a stack of aluminium fins and expanding the tubes mechanically. The mechanical expansion is achieved by inserting a steel bullet through the tube. The steel bullet has a larger diameter than the tube and the expansion provides a firm surface contact between fins and tubes. Five bullet expansion ratios (i.e. 1.045 to 1.059) have been used in the study to expand a 9.52mm diameter tubes in a fin-tube heat exchanger. The study is conducted on a water-to-water loop experiment rig under steady state conditions. In addition, the effects of fin hardness and fin pitch are investigated in the study. The results indicate that the optimum heat transfer occurred at a bullet expansion ratio ranging from 1.049 to 1.052. It is also observed that larger fin pitches require larger bullet expansion ratios, especially with lower fin hardness. As the fin pitch increases, both fin hardness (i.e. H22 and H24) exhibit increasing heat transfer rate per fin (W/fin). With the H22 hardness temper, the increase is as much as 11% while H24 increases by 1.2%.

  15. An investigation on SA 213-Tube to SA 387-Tube plate using friction welding process

    Energy Technology Data Exchange (ETDEWEB)

    Rajan, S. Pandia; Kumaraswamidhas, L. A. [Indian Institute of Technology, Jharkhand (India); Kumaran, S. Senthil [RVS School of Engineering and Technology, Tamil Nadu (India); Muthukumaran, S. [National Institute of Technology, Tamil Nadu (India)

    2016-01-15

    Friction welding of tube to tube plate using an external tool (FWTPET) is a relatively newer solid state welding process used for joining tube to tube plate of either similar or dissimilar materials with enhanced mechanical and metallurgical properties. In the present study, FWTPET has been used to weld SA 213 (Grade T12) tube with SA 387 (Grade 22) tube plate. The welded samples are found to have satisfactory joint strength and the Energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD) study showed that inter metallic compound is absent in the weld zone. The different weld joints have been identified and the phase composition is found using EDX and XRD. Microstructures have been analyzed using optical and Scanning electron microscopy (SEM). The mechanical properties such as hardness, compressive shear strength and peel test for different weld conditions are studied and the hardness survey revealed that there is increase in hardness at the weld interface due to grain refinement. The corrosion behavior for different weld conditions have been analyzed and the weld zone is found to have better corrosion resistance due to the influence of the grain refinement after FWTPET welding process. Hence, the present investigation is carried out to study the behavior of friction welded dissimilar joints of SA 213 tube and SA 387 tube plate joints and the results are presented. The present study confirms that a high quality tube to tube plate joint can be achieved using FWTPET process at 1120 rpm.

  16. Gastrostomy Tube Placement Without Nasogastric Tube: A Retrospective Evaluation in 85 Patients

    Energy Technology Data Exchange (ETDEWEB)

    Heberlein, Wolf E., E-mail: weheberlein@uams.edu; Goodwin, Whitney J.; Wood, Clint E.; Yousaf, Muhammad; Culp, William C. [University of Arkansas for Medical Sciences, Department of Radiology (United States)

    2012-12-15

    Purpose: Our study evaluated techniques for percutaneous gastrostomy (G)-tube placement without the use of a nasogastric (NG) tube. Instead, direct puncture of a physiologic air bubble or effervescent-enhanced gastric bubble distention was performed in patients with upper digestive tract obstruction (UDTO) or psychological objections to NG tubes. Materials and Methods: A total of 886 patients underwent G-tube placement in our department during a period of 7 years. We present our series of 85 (9.6%) consecutive patients who underwent percutaneous G-tube placement without use of an NG tube. Results: Of these 85 patients, fluoroscopic guided access was attempted by direct puncture of a physiologically present gastric air bubble in 24 (28%) cases. Puncture of an effervescent-induced large gastric air bubble was performed in 61 (72%) patients. Altogether, 82 (97%) of 85 G tubes were successfully placed in this fashion. The three failures comprised refusal of effervescent, vomiting of effervescent, and one initial tube misplacement when a deviation from our standard technique occurred. Conclusion: The described techniques compare favorably with published large series on G-tube placement with an NG tube in place. The techniques are especially suited for patients with UDTO due to head, neck, or esophageal malignancies, but they should be considered as an alternative in all patients. Direct puncture of effervescent-enhanced gastric bubble distention is a safe, patient-friendly and effective technique.

  17. Nervous system examination on YouTube

    OpenAIRE

    2012-01-01

    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”, “...

  18. Piping and tubing technology: A compilation

    Science.gov (United States)

    1971-01-01

    A compilation on the devices, techniques, and methods used in piping and tubing technology is presented. Data cover the following: (1) a number of fittings, couplings, and connectors that are useful in joining tubing and piping and various systems, (2) a family of devices used where flexibility and/or vibration damping are necessary, (3) a number of devices found useful in the regulation and control of fluid flow, and (4) shop hints to aid in maintenance and repair procedures such as cleaning, flaring, and swaging of tubes.

  19. A miniature high repetition rate shock tube.

    Science.gov (United States)

    Tranter, R S; Lynch, P T

    2013-09-01

    A miniature high repetition rate shock tube with excellent reproducibility has been constructed to facilitate high temperature, high pressure, gas phase experiments at facilities such as synchrotron light sources where space is limited and many experiments need to be averaged to obtain adequate signal levels. The shock tube is designed to generate reaction conditions of T > 600 K, P shock waves with predictable characteristics are created, repeatably. Two synchrotron-based experiments using this apparatus are also briefly described here, demonstrating the potential of the shock tube for research at synchrotron light sources.

  20. Six-Inch Shock Tube Characterization

    Science.gov (United States)

    2016-12-09

    USAARL Report No. 2017-08 Six-Inch Shock Tube Characterization By Michael Chen1,2, J. Trevor McEntire1,3, Miles Garwood1,3, Devyn...2016 - Nov 2016 Six-Inch Shock Tube Characterization N/A N/A N/A N/A N/A N/A Chen, Michael McEntire, J. Trevor Garwood, Miles Gentzyel, Devyn U.S...Auditory Protection and Performance Division (APPD) owns, operates, and maintains a 6-inch inner diameter shock tube to create shock waves in a

  1. Utility of Lava Tubes on Other Worlds

    Science.gov (United States)

    Walden, Bryce E.; Billings, T. L.; York, Cheryl Lynn; Gillett, S. L.; Herbert, M. V.

    1998-01-01

    On Mars, as on Earth, lava tubes are found in the extensive lava fields associated with shield volcanism. Lunar lava-tube traces are located near mare-highland boundaries, giving access to a variety of minerals and other resources, including steep slopes, prominent heights for local area communications and observation, large-surface areas in shade, and abundant basalt plains suitable for landing sites, mass-drivers, surface transportation, regolith harvesting, and other uses. Methods for detecting lava tubes include visual observations of collapse trenches and skylights, ground-penetrating radar, gravimetry, magnetometry, seismography, atmospheric effects, laser, lidar, infrared, and human or robotic exploration.

  2. Noninflammatory fallopian tube pathology in children

    Energy Technology Data Exchange (ETDEWEB)

    Merlini, Laura; Anooshiravani, Mehrak; Hanquinet, Sylviane [University Hospital HUG, Unit of Pediatric Radiology, Geneva (Switzerland); Vunda, Aaron [University Hospital, Clinic of Pediatric Surgery, Geneva (Switzerland); Borzani, Irene; Napolitano, Marcello [Ospedale Buzzi, Pediatric Radiology, Milan (Italy)

    2008-12-15

    Noninflammatory tubal abnormalities are rare in children and usually not well covered by traditional educational material. The presenting symptoms are nonspecific and are common to many other conditions, so its preoperative diagnosis is rarely made. The purpose of this study was to review the hospital charts and imaging findings in children and sexually inactive adolescents who showed fallopian tube pathology. Understanding of the pertinent findings of previous imaging examinations might assist radiologists in making the correct preoperative diagnosis and increase the likelihood of preserving the fallopian tubes. The clinical entities described in this article include isolated tubal torsion, paratubal cysts, hydrosalpinx, undescended/ectopic fallopian tube, and tubal inguinal hernia. (orig.)

  3. Pseudothrombocytopenia with multiple anticoagulant sample collection tubes

    Science.gov (United States)

    Kovacs, Ferenc; Varga, Marina; Pataki, Zsolt; Rigo, Erzsebet

    2016-01-01

    The knowledge of pseudothrombocytopenia (PTCP) is important for the accuracy of a clinical assessment and for avoiding unnecessary treatment. An elderly patient was hospitalized with left lung pneumonia. Severe thrombocytopenia [platelet (PLT) number: 18 × 109/L] without any clinical bleeding was found in ethylenediaminetetraacetic acid blood collection tube. PLT measurement was repeated in various anticoagulant [sodium citrate, lithium heparin, disodium oxalate, hirudin, and magnesium sulfate (Mg-sulfate)] sample collection tubes and all of them showed thrombocytopenia except with Mg-sulfate. To the best of our knowledge, PTCP with five anticoagulant sample collection tubes has not been reported earlier.

  4. Visualization of Flows in Turbomachinery.

    Science.gov (United States)

    1987-12-01

    determined using a Fo tube placed in the mid section of the wind tunnel - 11 - window Pitot tuboe FAir inlet T’ A ,, L (indoor) ’ i test section. perspex...wind tunnel has a rectangular section. A Pitot tube (4) was installed to estimate the free velocity. A schematic view of this arrangement is shown in

  5. The Multiple Silicone Tube Device, “Tubes within a Tube,” for Multiplication in Nerve Reconstruction

    Directory of Open Access Journals (Sweden)

    Fredrik Johansson

    2014-01-01

    Full Text Available Multiple nerve branches were created during the regeneration procedure after a nerve injury and such multiple branches are suggested to be used to control, for example, prosthesis with many degrees of freedom. Transected rat sciatic nerve stumps were inserted into a nine mm long silicone tube, which contained four, five mm long, smaller tubes, thus leaving a five mm gap for regenerating nerve fibers. Six weeks later, several new nerve structures were formed not only in the four smaller tubes, but also in the spaces in-between. The 7–9 new continuous nerve structures, which were isolated as individual free nerves after removal of the tubes, were delineated by a perineurium and contained both myelinated and unmyelinated nerve fibers as well as blood vessels. Stimulation of the proximal nerve elicited contractions in distal muscles. Thin metal electrodes, inserted initially into the smaller tubes in some experiments, became embedded in the new nerve structures and when stimulated contractions of the distal muscles were observed. The “tubes within a tube” technique, creating multiple new nerves from a single “mother” nerve, can be used to record multiple signals for prosthetic device control or as sources for supply of multiple denervated targets.

  6. Chemical milling of Zircaloy tubing to produce integral OD spiral finned tubes (AWBA development program)

    Energy Technology Data Exchange (ETDEWEB)

    Horwood, W.A.

    1982-02-01

    A detailed process description is provided for producing integral spiral fins on the outside surface of Zircaloy nuclear fuel cladding tubes by masking with pressure sensitive tape strips and then chemical milling (pickling) the tube wall between the tape strips to leave the fins in relief. Fins up to 0.020 inch high by 0.05 to 0.12 inch wide were consistently produced on tubes having wall thickness of 0.008 inch or greater after fin pickling. Wall thickness uniformity was excellent. Information is provided on tube surface preparation to maximize tape mask adhesion time during pickling, acid chemistry control to prevent local tube wall thinning near the fin, and pickling techniques to promote uniform material removal. Simple fixture designs are described for quickly and conveniently applying the tape strips to the tube wall in an accurate spiral. 13 figures, 4 tables.

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

    Science.gov (United States)

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

    2017-02-01

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

  8. 21 CFR 872.6570 - Impression tube.

    Science.gov (United States)

    2010-04-01

    ... DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6570 Impression tube. (a) Identification. An impression... material, such as wax, the remaining end is slipped over the tooth to make the impression....

  9. Advanced Illness: Feeding Tubes and Ventilators

    Science.gov (United States)

    ... the feedings may be difficult. There is some debate, for example, about whether feeding tubes actually extend ... pneumonia cannot, but people can now get a vaccination to prevent many kinds of viral pneumonia. Aspiration ...

  10. Wave propagation in spatially modulated tubes

    CERN Document Server

    Ziepke, A; Engel, H

    2016-01-01

    We investigate wave propagation in rotationally symmetric tubes with a periodic spatial modulation of cross section. Using an asymptotic perturbation analysis, the governing quasi two-dimensional reaction-diffusion equation can be reduced into a one-dimensional reaction-diffusion-advection equation. Assuming a weak perturbation by the advection term and using projection method, in a second step, an equation of motion for traveling waves within such tubes can be derived. Both methods predict properly the nonlinear dependence of the propagation velocity on the ratio of the modulation period of the geometry to the intrinsic width of the front, or pulse. As a main feature, we can observe finite intervals of propagation failure of waves induced by the tube's modulation. In addition, using the Fick-Jacobs approach for the highly diffusive limit we show that wave velocities within tubes are governed by an effective diffusion coefficient. Furthermore, we discuss the effects of a single bottleneck on the period of pul...

  11. Inverse Kinematics of Concentric Tube Steerable Needles

    Science.gov (United States)

    Sears, Patrick; Dupont, Pierre E.

    2013-01-01

    Prior papers have introduced steerable needles composed of precurved concentric tubes. The curvature and extent of these needles can be controlled by the relative rotation and translation of the individual tubes. Under certain assumptions on the geometry and design of these needles, the forward kinematics problem can be solved in closed form by means of algebraic equations. The inverse kinematics problem, however, is not as straightforward owing to the nonlinear map between relative tube displacements and needle tip configuration as well as to the multiplicity of solutions as the number of tubes increases. This paper presents a general approach to solving the inverse kinematics problem using a pseudoinverse solution together with gradients of nullspace potential functions to enforce geometric and mechanical constraints. PMID:23685532

  12. Stabilization Strategies for Drift Tube Linacs

    CERN Document Server

    AUTHOR|(CDS)2085420; Lamehi Rashti, Mohammad

    The average axial electric fields in drift tube linac cavities are known to be sensitive with respect to the perturbation errors. Postcoupler is a powerful stabilizer devices that is used to reduce this sensitivity of average axial field. Postcouplers are the cylindrical rod which is extended from cavity wall toward the drift tube without touching the drift tube surface. Postcouplers need to be adjusted to the right length to stabilize the average axial field. Although postcouplers are used successfully in many projects, there is no straightforward procedure for postcouplers adjustment and it has been done almost based on trial and errors. In this thesis, the physics and characteristics of postcouplers has been studied by using an equivalent circuit model and 3D finite element method calculations. Finally, a straightforward and accurate method to adjust postcouplers has been concluded. The method has been verified by using experimental measurements on CERN Linac4 drift tube linac cavities.

  13. 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.

  14. Performance of a tapered pulse tube

    Energy Technology Data Exchange (ETDEWEB)

    Swift, G.; Allen, M.; Woolan, J.J. [Cryenco Inc., Denver, CO (United States)

    1998-02-01

    In a well instrumented pulse tube refrigerator having 1,500 W of cooling power at 125 K, the authors have measured the figure of merit of a tapered pulse tube at several operating points. At operating points near the operating point for which the taper was designed, the figure of merit is 0.96. This is close to the theoretical optimum figure of merit 0.97 calculated for this pulse tube considering only two loss mechanisms: heat conduction in the metal pulse tube wall and ordinary thermoacoustic heat transport in the gas within a few thermal penetration depths of the wall. At operating points farther from the design operating point, the measured figure of merit is much lower, as streaming driven convection adds a third loss mechanism.

  15. SPECIAL PURPOSE SHOCK TUBE for BLAST ASSESSMENT

    Data.gov (United States)

    Federal Laboratory Consortium — This device is a specially designed shock tube for testing fabric samples in a controlled environment. The device determines the appropriate types of sensors to be...

  16. Staged multi-tube premixing injector

    Energy Technology Data Exchange (ETDEWEB)

    Zuo, Baifang; Khan, Abdul Rafey; York, William David; Ziminsky, Willy Steve

    2012-10-02

    A fuel injection nozzle includes a body member having an upstream wall opposing a downstream wall, and an internal wall disposed between the upstream wall and the downstream wall, a first chamber partially defined by the an inner surface of the upstream wall and a surface of the internal wall, a second chamber partially defined by an inner surface of the downstream wall and a surface of the internal wall a first gas inlet communicative with the first chamber operative to emit a first gas into the first chamber, a second gas inlet communicative with the second chamber operative to emit a second gas into the second chamber, and a plurality of mixing tubes, each of the mixing tubes having a tube inner surface, a tube outer surface, a first inlet communicative with an aperture in the upstream wall operative to receive a third gas.

  17. A simple device to teach tube thoracostomy.

    Science.gov (United States)

    Ching, Jessica A; Wachtel, Thomas L

    2011-06-01

    Chest tube insertion is an important component of medical and surgical education. This article reports a cost-effective and easily reproducible method for hands-on education of tube thoracostomy placement. A wood base is constructed, and a large rack of ribs are secured to simulate the thorax. Partially inflated examination gloves and bagels are used to simulate the lung and diaphragm, respectively. A life-like, cost-efficient thoracostomy model is created allowing for proficiency training in chest tube insertion. According to Advanced Trauma Life Support criteria, 123 military personnel were satisfactory, 4 remedial, and 7 instructor potential using the described model. We have developed a simple, inexpensive training device for insertion of chest tubes and tested it on 134 military personnel.

  18. 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.

  19. Water Oscillation in an Open Tube

    Directory of Open Access Journals (Sweden)

    Doh Hoon Chung

    2008-01-01

    Full Text Available When an open tube is placed in a tank of water, covered on top, raised, and then uncovered, the water inside the tube will oscillate. The characteristics of the oscillation of the water inside the tube were studied. It was shown that, for large oscillations, the top half-period was longer than the bottom half period due to the increased mass of the water column. For small oscillations, it approached simple harmonic motion, with the square of the period varying with mean length, as predicted by theory. An end correction was also shown to exist, due to the motion of the water outside the bottom of the tube during the oscillation. The end correction was shown to be independent of the mean length of the water column, as predicted.

  20. Medical Informatics Idle YouTube Potential.

    Science.gov (United States)

    Hucíková, Anežka; Babic, Ankica

    2017-01-01

    YouTube as an online video-sharing service in the context of Web 2.0 goes beyond the bounds of pure fun, for which the platform was primarily established. Nowadays, commonly to other social media, it serves also educational, informational and last but not least, marketing purposes. The importance of video sharing is supported by several predictions about video reaching over 90% of global internet traffic by 2020. Using qualitative content analysis over selected YouTube videos, paper examines the current situation of the platform's marketing potential usage by medical informatics organizations, researches and other healthcare professionals. Results of the analysis demonstrate several ways in which YouTube is already used to inform, educate or promote above-mentioned medical institutions. However, their engagement in self-promo or spreading awareness of their research projects via YouTube is considered to be low.

  1. Performance of a tapered pulse tube

    Energy Technology Data Exchange (ETDEWEB)

    Swift, G.; Allen, M.; Woolan, J.J. [Cryenco Inc., Denver, CO (United States)

    1998-02-01

    In a well instrumented pulse tube refrigerator having 1,500 W of cooling power at 125 K, the authors have measured the figure of merit of a tapered pulse tube at several operating points. At operating points near the operating point for which the taper was designed, the figure of merit is 0.96. This is close to the theoretical optimum figure of merit 0.97 calculated for this pulse tube considering only two loss mechanisms: heat conduction in the metal pulse tube wall and ordinary thermoacoustic heat transport in the gas within a few thermal penetration depths of the wall. At operating points farther from the design operating point, the measured figure of merit is much lower, as streaming driven convection adds a third loss mechanism.

  2. A review of pulse tube refrigeration

    Science.gov (United States)

    Radebaugh, Ray

    This paper reviews the development of the three types of pulse tube refrigerators: basic, resonant, and orifice types. The principles of operation are given. It is shown that the pulse tube refrigerator is a variation of the Stirling-cycle refrigerator, where the moving displacer is substituted by a heat transfer mechanism or by an orifice to bring about the proper phase shifts between pressure and mass flow rate. A harmonic analysis with phasors is described which gives reasonable results for the refrigeration power, yet is simple enough to make clear the processes which give rise to the refrigeration. The efficiency and refrigeration power are compared with those of other refrigeration cycles. A brief review is given of the research being done at various laboratories on both one- and two-stage pulse tubes. A preliminary assessment of the role of pulse tube refrigerators is discussed.

  3. Techniques for Thermal Damping in Tube Bundles

    Directory of Open Access Journals (Sweden)

    QAMAR IQBAL

    2010-10-01

    Full Text Available Flow-induced vibration in heat exchangers has been a source of concern in the process, power generation and nuclear industry for several decades. Damping has a major influence on the flow induced vibrations and is dependant on a variety of factors such as mechanical properties of the tube material, geometry of intermediate supports, the physical properties of shell-side fluid, type of tube motion, number of supports, tube frequency, shell-side temperature etc. Various damping mechanisms have been identified and quantified. Generally the effects of the higher operating temperatures on the various damping mechanisms are neglected in the general design procedure. This paper focuses on the thermal aspects of damping mechanisms subjected to single phase cross-flow in shell and tube heat exchanger and a comparison is carried out safer design based on experimental and empirical formulations.

  4. Integrity Assessment of GOH Heater Tube

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Bong Sang; Hong, J. H.; Oh, Y. J.; Yoon, J. H.; Oh, J. M. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1997-08-01

    An assessment of structural integrity of ASTM A312-TP347 GOH heater tube was performed. The surface notches which had been produced during tube manufacturing process were analyzed microscopically. Chemical analysis, hardness tests, tensile tests, and J-Integral fracture resistance tests were carried out to compare the mechanical properties with those of the material specification and also with the other material of the same type. The test results showed the mechanical properties of the GOH tube material are within the specification range. An elastic-plastic fracture mechanics analysis based on the DPFAD method reveals the tube an appropriate safety margin for the normal operation. 13 refs., 5 tabs., 24 figs. (author)

  5. Syringosubarachnoid shunting using a myringotomy tube

    Directory of Open Access Journals (Sweden)

    Jack M Leschke

    2016-01-01

    Conclusion: We used a myringotomy tube for syringosubarachnoid shunting for the surgical management of a posttraumatic syrinx with good results. This technique minimizes suturing and may minimize shunt-related complications.

  6. Fewer Advanced Alzheimer's Patients on Feeding Tubes

    Science.gov (United States)

    ... medlineplus.gov/news/fullstory_160456.html Fewer Advanced Alzheimer's Patients on Feeding Tubes Practice dropped by half ... organizations -- is declining, a new study finds. One Alzheimer's expert who reviewed the new findings was heartened ...

  7. Investigation of a twisted-tube type shell-and-tube heat exchanger

    OpenAIRE

    Danielsen, Sven Olaf

    2009-01-01

    This master thesis investigates twisted tube type shell-and-tube heat exchangers with emphasis on thermal-hydraulic characteristics, fouling and vibration properties. An extensive literature study has been carried out in order to map all published research reports written on the topic. The mapping of performed research shows that the available information is limited.Mathematical correlations for twisted tube thermal-hydraulic characteristics are extracted from the research reports found in th...

  8. Moving magnetic tubes: fragmentation, vortex streets and the limit of the approximation of thin flux tubes

    Science.gov (United States)

    Cheung, M. C. M.; Moreno-Insertis, F.; Schüssler, M.

    2006-05-01

    Aims.We study the buoyant rise of magnetic flux tubes in a stratified layer over a range of Reynolds numbers (25 ⪉ Re ⪉ 2600) by means of numerical simulations. Special emphasis is placed on studying the fragmentation of the rising tube, its trailing wake and the formation of a vortex street in the high-Reynolds number regime. Furthermore, we evaluate the relevance of the thin flux tube approximation with regard to describing the evolution of magnetic flux tubes in the simulations. Methods: .We used the FLASH code, which has an adaptive mesh refinement (AMR) algorithm, thus allowing the simulations to be carried out at high Reynolds numbers. Results: .The evolution of the magnetic flux tube and its wake depends on the Reynolds number. At Re up to a few hundred, the wake consists of two counter-rotating vortex rolls. At higher Re, the vortex rolls break up and the shedding of flux into the wake occurs in a more intermittent fashion. The amount of flux retained by the central portion of the tube increases with the field line twist (in agreement with previous literature) and with Re. The time evolution of the twist is compatible with a homologous expansion of the tube. The motion of the central portion of the tube in the simulations is very well described by the thin flux tube model whenever the effects of flux loss or vortex forces can be neglected. If the flux tube has an initial net vorticity, it undergoes asymmetric vortex shedding. In this case, the lift force accelerates the tube in such a way that an oscillatory horizontal motion is super-imposed on the vertical rise of the tube, which leaves behind a vortex street. This last result is in accordance with previous simulations reported in the literature, which were carried out at lower Reynolds number.

  9. Sound absorption and reflection with coupled tubes

    OpenAIRE

    2000-01-01

    This paper describes a special sound absorbing technique with an accompanying efficient numerical design tool. As a basis pressure waves in a single narrow tube or pore are considered. In such a tube the viscosity and the thermal conductivity of the air, or any other fluid, can have a significant effect on the wave propagation. An important aspect is that due to the viscothermal wave propagation sound energy is being dissipated. This has been applied to configurations consisting of a manifold...

  10. Endotracheal Tube Cuff Management at Altitude

    Science.gov (United States)

    2014-02-05

    model study of endotracheal intubation including mechanical ventilation and four methods of cuff pressure management during ascent and descent...AFRL-SA-WP-SR-2014-0007 Endotracheal Tube Cuff Management at Altitude SSgt Tyler J. Britton, RRT1; Richard D. Branson, RRT2...REPORT TYPE Special Report 3. DATES COVERED (From – To) June 2012 – December 2013 4. TITLE AND SUBTITLE Endotracheal Tube Cuff Management

  11. Endotracheal Tube Cuff Pressure Monitoring in Children

    Directory of Open Access Journals (Sweden)

    V. V. Lazarev

    2012-01-01

    Full Text Available Objective: to estimate tracheal morphological changes in children, by using a device for the continuous monitoring and regulation of endotracheal tube cuff pressure. Subjects and methods. Two groups of children were examined. In Group A comprising 22 children aged 2 months to 16 years, the adequacy of the external control balloon palpation method was estimated to measure endotracheal tube cuff pressure. In Group B consisting of 12 children aged 5 to 18 years on mechanical ventilation for more than 3 days, the efficiency and appropriateness of applying a PressureEasy device for monitoring the pressure in the endotracheal tube cuff were assessed to prevent postintubation tracheal complications. In the latter group, the authors identified a study subgroup (BI of 8 patients where this device was employed and a control group of 4 patients (BII where it was not used. Results. Group A showed that endotracheal tube cuff pressure was 20—30 cm H2O in 31.8% of cases, greater than 30 cm H2O in 36.4%, and lower than 20 cm H2O in 31.8%. Subgroup BI displayed considerably lower macro- and microscopic histological changes than Subgroup BII. Conclusion. Determination of endotracheal tube cuff pressure by palpation of the external control balloon does not reflect its real values. The magnitude of tracheal changes is more intensive if continuous monitoring and regulation of pressure in the endotracheal tube cuff is absent. The PressureEasy device to monitor endotracheal tube cuff pressure permits its variability maintenance at a given level, by mitigating the damaging effect of the cuff on tracheal tissue. Key words: endotracheal tube, cuff, histology, ischemia, prevention, pressure, trachea.

  12. Condensation of refrigerants on vertical fluted tubes

    Energy Technology Data Exchange (ETDEWEB)

    Combs, S.K.; Mailen, G.S.; Murphy, R.W.

    1978-08-01

    Experiments were run to determine heat transfer performance of single vertical fluted tubes with selected fluids condensing on the outside. Working fluids included six fluorocarbons (Refrigerants 11, 21, 22, 113, 114, and 115) and a hydrocarbon (Refrigerant 600a or isobutane). The nine test tubes were of 2.54-cm (1-in.) nominal outside diameter and 1.2 m (4 ft) in length with from 0 (smooth) to 60 axial flutes. Condensing heat transfer coefficients ranged from 620 to 7900 W/m/sup 2/ . K (110 to 1400 Btu/hr . ft/sup 2/ . /sup 0/F) over the heat flux range of 2000 to 43,000 W/m/sup 2/ (920 to 13,600 Btu/hr . ft/sup 2/). All parameters are based on total condensing surface area. The data show that, for a given heat flux, a fluted tube can increase condensing coefficients up to 6.0 times smooth tube values. Further heat transfer enhancement was achieved by the use of drainage skirts on fluted tubes; these skirts effectively divided the 1.2-m (4-ft) tubes into two, four, and eight equal condensing lengths.

  13. Chylothorax: a rare complication of tube thoracostomy.

    Science.gov (United States)

    Limsukon, Atikun; Yick, Dennis; Kamangar, Nader

    2011-03-01

    Chylothorax resulting from chest tube injury to the thoracic duct is very rare and underreported. The purpose of this case report is to exemplify this rare but potentially significant complication of chest tube thoracostomy. An 86-year-old woman presented with sepsis and a massive right pleural effusion; she developed a chylous effusion with the pleural fluid triglyceride level of 158 mg/dL 2 days after a traumatic chest tube insertion. All investigations excluded common causes of non-traumatic chylothorax. The chylothorax improved after fasting and implementation of a medium-chain triglyceride diet. The optimal depth of insertion of the chest tube typically ranges from 5 to 15 cm, ensuring all sideports are within the chest and the proximal port is at least 2 cm beyond the rib margin. Traumatic chylothorax secondary to chest tube insertion should be included in the differential diagnosis of patients presenting with chylothorax after a thoracostomy tube. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. Complications of tube thoracostomy in trauma

    Science.gov (United States)

    Bailey, R

    2000-01-01

    Objective—To assess the complication rate of tube thoracostomy in trauma. To consider whether this rate is high enough to support a selective reduction in the indications for tube thoracostomy in trauma. Methods—A retrospective case series of all trauma patients who underwent tube thoracostomy during a 12 month period at a large UK teaching hospital with an accident and emergency (A&E) department seeing in excess of 125 000 new patients/year. These patients were identified using the hospital audit department computerised retrieval system supplemented by a hand search of both the data collected for the Major Trauma Outcome Study and the A&E admission unit log book. The notes were assessed with regard to the incidence of complications, which were divided into insertional, infective, and positional. Results—Fifty seven chest drains were placed in 47 patients over the 12 month period. Seven patients who died within 48 hours of drain insertion were excluded. The commonest indications for tube thoracostomy were pneumothorax (54%) and haemothorax (20%); 90% of tubes were placed as a result of blunt trauma. The overall complication rate of the procedure was 30%. There were no insertional complications and only one (2%) major complication, which was empyema thoracis. Conclusion—This study reveals no persuasive evidence to support a selective reduction in the indications for tube thoracostomy in trauma. A larger study to confirm or refute these findings must be performed before any change in established safe practice. PMID:10718232

  15. Ultimate Temperature of Pulse Tube Cryocoolers

    Science.gov (United States)

    Kittel, P.

    2010-04-01

    An ideal pulse tube cryocooler using an ideal gas can operate at any temperature. This is not true for real gasses. The enthalpy flow resulting from the real gas effects of 3He, 4He, and their mixtures in ideal pulse tube cryocoolers puts limits on the operating temperature of pulse tube cryocoolers. The discussion of these effects follows a previous description of the real gas effects in ideal pulse tube cryocoolers and makes use of models of the thermophysical properties of 3He and 4He. Published data is used to extend the analysis to mixtures of 3He and 4He. The analysis was done for pressures below 2 MPa and temperatures below 2.5 K. Both gasses and their mixtures show low temperature limits for pulse tube cryocoolers. These limits are in the 0.5-2.2 K range and depend on pressure and mixture. In some circumstances, even lower temperatures may be possible. Pulse tube cryocoolers using the two-fluid properties of dilute 3He in superfluid 4He appear to have no limit.

  16. A simple theory of Rijke tube oscillation

    Institute of Scientific and Technical Information of China (English)

    Maa Dah-You

    2002-01-01

    A simple theory of Rijke tube oscillation is presented based on mathematical realization of Rayleigh's qualitative explanation of the mechanism of Rijke tube. This is done by assuming a single point of high temperature in an otherwise uniform tube and the sound source produced when cold air flows passing this point. The wave equation thus obtained is then rigorously solved. It is found that the Rijke tube oscillation is a feedback system. There is no feedback nor oscillation when the hot spot is at a node or antinode in the tube. The mean flow is necessary for the oscillation, the particle velocity of which is proportional to the mean velocity, and the ratio is proportional to the gauze temperature when the later is low and the feedback does not affect much the magnitude of the particle velocity. When the temperature is high, the feedback increases rapidly and the particle velocity might grow to several or even tens of times of the mean velocity, and almost indefinitely when the heater temperature is high enough. Otherwise the growth is rather slow, when the mean flow or high temperature is first applied. The oscillations stop immediately when the mean flow is stopped. If the mean flow is controlled by a valve or a paddle at one end of the tube, an interesting sound is produced.

  17. Experimental Investigation on Heat Transfer and Frictional Characteristics of Shell-and-tube Heat exchangers with Different Baffles and Tubes

    Science.gov (United States)

    Wang, C.; Zhu, J. G.; Sang, Z. F.

    2010-03-01

    In this study, the heat transfer and tube frictional characteristics of the helixchangers (shell-and-tube heat exchanger with helical baffles) with spirally corrugated and smooth tubes and the conventional shell-and-tube heat exchanger with smooth tubes were experimentally obtained. The results show that the helixchangers with the spirally corrugated tube and the smooth tubes enhance the total heat transfer coefficient about 26% and 7% on the average than the segmental baffled heat exchanger. In the tube side, the spirally corrugated tube leads to about 28% average increase on convective heat transfer performance and about 24% average increase on pressure drop than the smooth tube, but its conversion efficiency is still higher. The helical baffle could enhance the shell-side condensation coefficient by 13%, and the spirally corrugated tube could help the helixchanger with it enhance remarkably the condensation performance by 53% than the segmental baffled heat exchanger.

  18. Influence of tube's diameter on boiling heat transfer performance in small diameter tubes

    Science.gov (United States)

    Gan, Chengjun; Wang, Weicheng; Zhang, Lining

    1998-03-01

    This paper reports the experiments of evaporation study in 6 mm inner copper diameter tubes using HFC-134a, HCFC-22 and CFC-12 as working fluid. The results show that the evaporation heat transfer coefficient increases with the decreasing of inner diameter of tubes. A new concept of non-dimensional tube diameter U is proposed in this paper for correction of the influence of the tube diameter on the evaporation heat transfer coefficient. And further, a convenient empirical correction method is presented.

  19. Improvement of pump tubes for gas guns and shock tube drivers

    Science.gov (United States)

    Bogdanoff, D. W.

    1990-01-01

    In a pump tube, a gas is mechanically compressed, producing very high pressures and sound speeds. The intensely heated gas produced in such a tube can be used to drive light gas guns and shock tubes. Three concepts are presented that have the potential to allow substantial reductions in the size and mass of the pump tube to be achieved. The first concept involves the use of one or more diaphragms in the pump tube, thus replacing a single compression process by multiple, successive compressions. The second concept involves a radical reduction in the length-to-diameter ratio of the pump tube and the pump tube piston. The third concept involves shock heating of the working gas by high explosives in a cyclindrical geometry reusable device. Preliminary design analyses are performed on all three concepts and they appear to be quite feasible. Reductions in the length and mass of the pump tube by factors up to about 11 and about 7, respectively, are predicted, relative to a benchmark conventional pump tube.

  20. Dynamic Experimental Study of a Multi—bypass Pulse Tube Refrigerator with Two—bypass Tubes

    Institute of Scientific and Technical Information of China (English)

    YonglinJu; ChaoWang; 等

    1998-01-01

    A dynamic experimental apparatus to measure the instantaneous velocity and pressure in the multibypass pulse tube refrigerator(MPTR) was designed and constructed.Some important experimental results of the instantaneous measurements of the velocity and the pressure in the MPTR with twobypass tubes during actual operation are prsented.The effects of the middle-bypass version on the dynamic pressure and mass flow rate at the cold end of the pulse tube are ev aluated from experimental measurements.DC-flow phenomena are observed in this MPTR.The reasons of the multi-bypass version improved the performance of pulse tube refrigertor are given.

  1. Heat exchanger with helical bundles of finned tubes

    Energy Technology Data Exchange (ETDEWEB)

    Eyking, H.J.

    1975-01-23

    The invention applies to a heat exchanger with helical bundles of tubes consisting of finned tubes separated by spacers. The spacers are designed as closed holding cylinders with holding devices for the tube bundles, each ot which surrounds a bundle of tubes. This construction serves to simplify the production process and to enable the use of the heat exchanger at higher loads.

  2. The Functionality of Paratexts on YouTube

    DEFF Research Database (Denmark)

    Simonsen, Thomas Mosebo

    2014-01-01

    This chapter investigates paratexts and their functionality on YouTube. It is argued that YouTube content is in fact characterized by its dependence and usage of paratexts as part of YouTube's infrastructure. Paratexts are presented as being either auto-generated by YouTube or created by its user...

  3. 21 CFR 888.4230 - Cement ventilation tube.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cement ventilation tube. 888.4230 Section 888.4230...) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4230 Cement ventilation tube. (a) Identification. A cement ventilation tube is a tube-like device usually made of plastic intended to be inserted...

  4. 46 CFR 171.100 - Shaft tunnels and stern tubes.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Shaft tunnels and stern tubes. 171.100 Section 171.100... stern tubes. (a) Stern tubes in each of the following vessels must be enclosed in watertight spaces: (1... passengers on an international voyage. (b) The watertight seal in the bulkhead between the stern tube space...

  5. Hand tool permits shrink sizing of assembled tubing

    Science.gov (United States)

    Millett, A.; Odor, M.

    1966-01-01

    Portable tool sizes tubing ends without disassembling the tubing installation. The shrink sizing tool is clamped to the tubing and operated by a ratchet wrench. A gear train forces the tubing end against an appropriate die or mandrel to effect the sizing.

  6. T-tube insertion for sclerotic subglottic stenosis.

    Science.gov (United States)

    Goto, Taichiro; Kato, Ryoichi

    2014-02-01

    T-tube insertion is effective treatment for subglottic stenosis, but it is generally difficult due to bending of the T-tube. In a 52-year-old woman with relapsing polychondritis, a T-tube was inserted after predilatation using Hegar dilators. We describe the details of our T-tube insertion methods for sclerotic subglottic stenosis.

  7. Testing of Colorimetric Tubes for Nitrogen Dioxide and Monomethylhydrazine.

    Science.gov (United States)

    Diamond, Philip

    Colorimetric tubes for nitrogen dioxide (NO2) and monomethylhydrazine (MMH) were tested for accuracy and results indicate that at the levels checked the tubes' average deviation was plus or minus 20 percent. Tube NO2 concentrations all read lower than the analyzed concentrations. MMH tubes read much higher than the analyzed concentration of 0.28…

  8. Recent integrity program for WWER steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Wilam, M.; Papp, L.

    1994-12-31

    Considerable effort was given to NPP steam generator (SG) tubes integrity investigations during last years. These evaluations were focused on vertical SG tubing, i.e. on INCONEL tubes with geometry typical for this type of SG. The Steam Generator Tubes Integrity Program was conducted in VITKOVICE, R and D using WWER SG tubes. These tubes are made of 08Ch18N10T type stainless steel that corresponds to AISI 321 grade. The outer diameter of WWER tubes is 16 mm and the wall thickness is 1.5 mm.

  9. Optimization of a Shell and Tube Condenser using Numerical Method

    Directory of Open Access Journals (Sweden)

    Pradeep Wagh

    2015-07-01

    Full Text Available The purpose of this study was to investigate the effect of installation of the tube external surfaces, their parameter and variable in a shell-and-tube condenser. Variation of heat transfer coefficient with each variable of shell and tube condenser was measured each test. The optimization tube outside diameter size was analyzed and use extended surface area attached tube with tube material and tube layout and arrangement (Number of tube a triangular or hexagonal arrangement on shell-and tube condenser. The computer programming was used to get faster output in less time. Results suggest that mean heat transfer coefficient in variable condition were mainly at velocity is fixed. And also average additional surfaces and tube layout and the arrangement comparison with the quantity of the heat transfer.

  10. Energy absorbing efficiency of various aluminum foam filled tube

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Jin Man; Lee, Won Sik; Ko, Se Hyun [Korea Institute of Industrial Technology, Chonan (Korea, Republic of)

    2005-04-15

    In this study various types of A1 foam filled tubes were fabricated using foam of A1-12wt.%Si by powder metallurgical process. Their energy absorbing efficiencies were investigated with compression test, focusing on the structure and bonding effects between tube and foam. The results show that the energy absorption is affected by structure of A1 foam filled tube. Among fully foam filled tube, partially foam filled tube and A1 hollow tube with the same weight, fully foam filled tube seems to have superior potential for industrial application to energy absorption parts. Also energy absorption efficiency is increased by interaction between tube and foam and especially, bonding between tube and metallic foam gives rise to increase the energy absorption efficiency up to above 1.2 times. This results from the arrest of folding of tube by metallic foam and the change of stress mode from uni-axial to multi-axial during compression.

  11. UNUSUAL SITE OF OBSTRUCTION IN A FLEXOMETALLIC TUBE

    Directory of Open Access Journals (Sweden)

    Habib Rahaman

    2014-12-01

    Full Text Available Maxillofacial procedure such as LeFort I osteotomy requires Transmyelohyoid Intubation. For that initial intubation is done with Flexometallic Endotracheal Tube so that this tube can be easily brought out through transmyelohyoid incision. Frequently Flexometallic tubes are reused after Ethylene Oxide Sterilisation because of high Cost. Here we present an obstruction to endotracheal tube at an unusual location, (Deformity of the tube at the level of Cuff, with intact cuff.

  12. Augmentation of Condensation Heat Transger by Finning of Tubes

    OpenAIRE

    1992-01-01

    This paper summarizes experimental and theoretical studies that have been performed in our laboratory to enhance condensation heat transfer on horizontal tubes and tube bundles by use of fins. Use of a drainge strip is proved to be very effective in further enhancing condensation heat transfer on the horizontal finned tube. Effects of fin geometry and tube arrangement on the condensation heat transfer performance of the tube bundle are investigated. A theoretical model is proposed to predict ...

  13. Automated Diagnosis and Classification of Steam Generator Tube Defects

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Gabe V. Garcia

    2004-10-01

    A major cause of failure in nuclear steam generators is tube degradation. Tube defects are divided into seven categories, one of which is intergranular attack/stress corrosion cracking (IGA/SCC). Defects of this type usually begin on the outer surface of the tubes and propagate both inward and laterally. In many cases these defects occur at or near the tube support plates. Several different methods exist for the nondestructive evaluation of nuclear steam generator tubes for defect characterization.

  14. Safe and adequate placement of nasogastric tubes in the presence of a cuffed tracheostomy tube.

    Science.gov (United States)

    Parmar, A; Macleod, I; McDonald, S; Tierney, P

    2011-09-01

    This case report and review of the literature aims to highlight the importance of the use of a chest radiograph to check the placement of nasogastric tubes after insertion in an awake patient with an inflated cuffed tracheostomy tube regardless of an acidic pH test.

  15. PROGRESS IN PROCESS INTENSIFICATION: SYNTHESIS OF IMINES USING A SPINNING TUBE-IN-TUBE REACTOR

    Science.gov (United States)

    The high purity, high throughput synthesis of a number of imines (Schiff bases) using a spinning tube-in-tube reactor (STT, Kreido Laboratories, Camarillo, CA) has been carried out. The STT reactor allows the high throughput production of high purity imines from a wide variety of...

  16. EPOXIDATION OF SMALL ORGANIC MOLECULES USING A SPINNING TUBE-IN-TUBE REACTOR

    Science.gov (United States)

    The commodity-scale epoxidation of several organic molecules has been carried out using a Spinning Tube-in-Tube (STTr) reactor (manufactured by Kreido Laboratories). This reactor, which embodies and facilitates the use of Green Chemistry principles and Process Intensification, a...

  17. PROGRESS IN PROCESS INTENSIFICATION: SYNTHESIS OF IMIDAZOLE DERIVATIVES USING A SPINNING TUBE-IN-TUBE REACTOR

    Science.gov (United States)

    The high purity, high throughput synthesis of a number of imidazole derivatives using a spinning tube-in-tube reactor (STT®, Kreido Laboratories, Camarillo California) has been carried out. The STT® reactor allows the high throughput production of high purity imidazole derivativ...

  18. Left-right differences in Eustachian tube function in children with ventilation tubes.

    NARCIS (Netherlands)

    Heerbeek, N. van; Akkerman, A.E.; Ingels, K.J.A.O.; Engel, J.A.M.; Zielhuis, G.A.

    2003-01-01

    OBJECTIVE: To study the intraindividual variation in Eustachian tube (ET) function in children with ventilation tubes. METHODS: The forced response test, the pressure equilibration test and the sniff test were performed on both ears of 148 children. The results of both ears were compared. RESULTS: N

  19. PROGRESS IN PROCESS INTENSIFICATION: SYNTHESIS OF IMIDAZOLE DERIVATIVES USING A SPINNING TUBE-IN-TUBE REACTOR

    Science.gov (United States)

    The high purity, high throughput synthesis of a number of imidazole derivatives using a spinning tube-in-tube reactor (STT®, Kreido Laboratories, Camarillo California) has been carried out. The STT® reactor allows the high throughput production of high purity imidazole derivativ...

  20. PROGRESS IN PROCESS INTENSIFICATION: SYNTHESIS OF IMINES USING A SPINNING TUBE-IN-TUBE REACTOR

    Science.gov (United States)

    The high purity, high throughput synthesis of a number of imines (Schiff bases) using a spinning tube-in-tube reactor (STT, Kreido Laboratories, Camarillo, CA) has been carried out. The STT reactor allows the high throughput production of high purity imines from a wide variety of...

  1. EPOXIDATION OF SMALL ORGANIC MOLECULES USING A SPINNING TUBE-IN-TUBE REACTOR

    Science.gov (United States)

    The commodity-scale epoxidation of several organic molecules has been carried out using a Spinning Tube-in-Tube (STTr) reactor (manufactured by Kreido Laboratories). This reactor, which embodies and facilitates the use of Green Chemistry principles and Process Intensification, a...

  2. Vibro-impact responses of a tube with tube--baffle interaction. [LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Y S; Sass, D E; Jendrzejczyk, J A

    1978-01-01

    The relatively small, inherent tube-to-baffle hole clearances associated with manufacturing tolerances in heat exchangers affect the vibrational characteristics and the response of the tube. Numerical studies were made to predict the vibro-impact response of a tube with tube-baffle interaction. The finite element method has been employed with a non-linear elastic contact spring-dashpot to model the effect of the relative approach between the tube and the baffle plate. The coupled equations of motion are directly integrated with a proportional system damping represented by a linear combination of mass and stiffness. Lumped mass approach with explicit time integration scheme was found to be a suitable choice for tube-baffle impacting analysis. Fourier analyses indicate that the higher mode contributions to the tube response are significant for strong tube-baffle impacting. The contact damping forces are negligible compared with the contact spring forces. The numerical analysis results are in reasonably good agreement with those of the experiments.

  3. Mini implant supported molar tubes: A novel method for attaching the molar tubes

    Directory of Open Access Journals (Sweden)

    Nitin V Muralidhar

    2017-01-01

    Full Text Available Banding or bonding procedures have been the only means of attaching molar tubes onto the permanent molar teeth till date in the field of orthodontics. This clinical innovation aims to include the use of mini implant for the purpose of attaching the molar tubes thereby eliminating the iatrogenic effects of banding and bonding of the teeth.

  4. Pitot pressure analyses in CO2 condensing rarefied hypersonic flows

    Science.gov (United States)

    Ozawa, T.; Suzuki, T.; Fujita, K.

    2016-11-01

    In order to improve the accuracy of rarefied aerodynamic prediction, a hypersonic rarefied wind tunnel (HRWT) was developed at Japan Aerospace Exploration Agency. While this wind tunnel has been limited to inert gases, such as nitrogen or argon, we recently extended the capability of HRWT to CO2 hypersonic flows for several Mars missions. Compared to our previous N2 cases, the condensation effect may not be negligible for CO2 rarefied aerodynamic measurements. Thus, in this work, we have utilized both experimental and numerical approaches to investigate the condensation and rarefaction effects in CO2 hypersonic nozzle flows.

  5. Wavefunction Properties of a Single and a System of Magnetic Flux Tube(s) Oscillations

    CERN Document Server

    Esmaeili, Shahriar; Dadashi, Neda; Safari, Hossein

    2015-01-01

    In this study, the properties of wavefunctions of the MHD oscillations for a single and a system of straight flux tubes are investigated. Magnetic flux tubes with a straight magnetic field and longitudinally density stratification under coronal conditions were considered. With repect to the density inhomogeneity in the radial direction of the flux tube, a smoothed step function at the lateral surface is employed. A single three-dimensional wave equation for longitudinal component of the perturbed magnetic field is solved using the finite element method (FEM). Wavefunctions of the MHD oscillations are categorized into kink, sausage, and torsional modes. Concerning the amplitude location of the waves which are arisen from the flux tube, those waves identified as body, surface, and leaky waves and appeared in both a single and a system of flux tubes cases. Exact recognition of the wavefunctions can be used in coronal seismology and also helps to future the high resolution instruments that would be designed for s...

  6. Premixed flame propagation in vertical tubes

    Science.gov (United States)

    Kazakov, Kirill A.

    2016-04-01

    Analytical treatment of the premixed flame propagation in vertical tubes with smooth walls is given. Using the on-shell flame description, equations for a quasi-steady flame with a small but finite front thickness are obtained and solved numerically. It is found that near the limits of inflammability, solutions describing upward flame propagation come in pairs having close propagation speeds and that the effect of gravity is to reverse the burnt gas velocity profile generated by the flame. On the basis of these results, a theory of partial flame propagation driven by a strong gravitational field is developed. A complete explanation is given of the intricate observed behavior of limit flames, including dependence of the inflammability range on the size of the combustion domain, the large distances of partial flame propagation, and the progression of flame extinction. The role of the finite front-thickness effects is discussed in detail. Also, various mechanisms governing flame acceleration in smooth tubes are identified. Acceleration of methane-air flames in open tubes is shown to be a combined effect of the hydrostatic pressure difference produced by the ambient cold air and the difference of dynamic gas pressure at the tube ends. On the other hand, a strong spontaneous acceleration of the fast methane-oxygen flames at the initial stage of their evolution in open-closed tubes is conditioned by metastability of the quasi-steady propagation regimes. An extensive comparison of the obtained results with the experimental data is made.

  7. [Nasogastric tubes: a lot of bother].

    Science.gov (United States)

    Tagliabue, Fabio; D'Angelo, Carlo; Zuccon, William; Giorgetta, Casimiro; Balduzzi, Valerio; Gambarini, Fabrizio; Bonandrini, Luigi

    2008-01-01

    The insertion of the nasogastric tube is one of the procedure that produces the most discomfort for the patients and practitioners. The AA, with the make use of their clinical experience and the data of the literature, report some personal reflections about the management of the nasogastric tube. The AA also analyse some variables (choice of the tube, approach to the patient, insertion of the tube, examination of the position, fixation and removal) that can influence on discomfort of the patient. The choice of the most right SNG is an important moment for the correct insertion; an effect we need to adjust the material and diameter of the tube to the prearranged use. The common practice demonstrates that the collaboration with the patient, obtained by "direct" and "indirect" strategies, gives more possibilities to immediately success of this procedure. The literature explains that it is possible to decrease the discomfort with topical anesthesia; still there are some points of view to clarify. From analyse of the different methods to check the position of SNG, the pH test of the aspirating fluid is the best solution. Once examination of right placement, we need to fix in different points (at least two). From personal experience the removal of SNG is better tolerate that the insertion because the patient is more conscious to be on the mend. The principal recommendation is to abstain from insertion of SNG if it is not closely necessary!

  8. 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.

  9. Confocal microlaparoscope for imaging the fallopian tube

    Science.gov (United States)

    Wu, Tzu-Yu; Rouse, Andrew R.; Chambers, Setsuko K.; Hatch, Kenneth D.; Gmitro, Arthur F.

    2014-11-01

    Recent evidence suggests that ovarian cancer can originate in the fallopian tube. 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. A rigid confocal microlaparoscope system designed to image the epithelial surface of the ovary in vivo was previously reported. A new confocal microlaparoscope with an articulating distal tip has been developed to enable in vivo access to human fallopian tubes. The new microlaparoscope is compatible with 5-mm trocars and includes a 2.2-mm-diameter articulating distal tip consisting of a bare fiber bundle and an automated dye delivery system for fluorescence confocal imaging. This small articulating device should enable the confocal microlaparoscope to image early stage ovarian cancer arising inside the fallopian tube. Ex vivo images of animal tissue and human fallopian tube using the new articulating device are presented along with in vivo imaging results using the rigid confocal microlaparoscope system.

  10. Experiments on a Miniature Hypervelocity Shock Tube

    Science.gov (United States)

    Tasker, Douglas; Johnson, Carl; Murphy, Michael; Lieber, Mark; MIMS Team

    2013-06-01

    A miniature explosively-driven shock tube, based on the Voitenko compressor design, has been designed to produce shock speeds in light gases in excess of 80 km/s. Voitenko compressors over 1 meter in diameter have been reported but here experiments on miniature shock tubes with ~1-mm bore diameters are described. In this design a 12-mm diameter explosive pellet drives a metal plate into a hemispherical gas compression chamber. Downstream from the piston a mica diaphragm separates the gas from an evacuated shock tube which is confined by a massive polymethylmethacrylate (PMMA) block. The diaphragm eventually ruptures under the applied pressure loading and the compressed gases escape into the evacuated shock tube at hyper velocities. The progress of gas shocks in the tube and bow shocks in the PMMA are monitored with an ultra-high-speed imaging system, the Shock Wave Image Framing Technique (SWIFT). The resulting time-resolved images yield two-dimensional visualizations of shock geometry and progression. By measuring both the gas and bow shocks, accurate and unequivocal measurements of shock position history are obtained. The experimental results were compared with those of hydrocode modeling to optimize the design. The first experiments were suboptimum in that the velocities were ~16 km/s. Progress with these experiments will be reported.

  11. Data analysis for steam generator tubing samples

    Energy Technology Data Exchange (ETDEWEB)

    Dodd, C.V.

    1996-07-01

    The objective of the Improved Eddy-Current ISI for Steam Generators program is to upgrade and validate eddy-current inspections, including probes, instrumentation, and data processing techniques for inservice inspection of new, used, and repaired steam generator tubes; to improve defect detection, classification and characterization as affected by diameter and thickness variations, denting, probe wobble, tube sheet, tube supports, copper and sludge deposits, even when defect types and other variables occur in combination; to transfer this advanced technology to NRC`s mobile NDE laboratory and staff. This report provides a description of the application of advanced eddy-current neural network analysis methods for the detection and evaluation of common steam generator tubing flaws including axial and circumferential outer-diameter stress-corrosion cracking and intergranular attack. The report describes the training of the neural networks on tubing samples with known defects and the subsequent evaluation results for unknown samples. Evaluations were done in the presence of artifacts. Computer programs are given in the appendix.

  12. Folate receptors and neural tube closure.

    Science.gov (United States)

    Saitsu, Hirotomo

    2017-02-28

    Neural tube defects (NTD) are among the most common human congenital malformations, affecting 0.5-8/1000 of live births. Human clinical trials have shown that periconceptional folate supplementation significantly decreases the occurrence of NTD in offspring. However, the mechanism by which folate acts on NTD remains largely unknown. Folate receptor (Folr) is one of the three membrane proteins that mediate cellular uptake of folates. Recent studies suggest that mouse Folr1 (formerly referred to as Fbp1) is essential for neural tube closure. Therefore, we examined spatial and temporal expression patterns of Folr1 in developing mouse embryos, showing a close association between Folr1 and anterior neural tube closure. Transient transgenic analysis was performed using lacZ as a reporter; we identified a 1.1-kb enhancer that directs lacZ expression in the neural tube and optic vesicle in a manner that is similar to endogenous Folr1. The 1.1-kb enhancer sequences were highly conserved between humans and mice, suggesting that human FOLR1 is associated with anterior neural tube closure in humans. Several experimental studies in mice and human epidemiological and genetics studies have suggested that folate receptor abnormalities are involved in a portion of human NTDs, although the solo defect of FOLR1 did not cause NTD.

  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. A prospective randomized trial of transnasal ileus tube vs nasogastric tube for adhesive small bowel obstruction

    Institute of Scientific and Technical Information of China (English)

    Xiao-Li Chen; Fena Ji; Qi Lin; Yi-Peng Chen; Jian-Jiang Lin; Feng Ye; Ji-Ren Yu; Yi-Jun Wu

    2012-01-01

    AIM:To study the therapeutic efficacy of a new transnasal ileus tube advanced endoscopically for adhesive small bowel obstruction.METHODS:A total of 186 patients with adhesive small bowel obstruction treated from September 2007 to February 2011 were enrolled into this prospective randomized controlled study.The endoscopically advanced new ileus tube was used for gastrointestinal decompression in 96 patients and ordinary nasogastric tube (NGT) was used in 90 patients.The therapeutic efficacy was compared between the two groups.RESULTS:Compared with the NGT group,the ileus tube group experienced significantly shorter time for relief of clinical symptoms and improvement in the findings of abdominal radiograph (4.1 ± 2.3 d vs 8.5 ± 5.0 d) and laboratory tests (P < 0.01).The overall effectiveness rate was up to 89.6% in the ileus tube group and 46.7% in the NGT group (P < 0.01).And 10.4% of the patients in the ileus tube group and 53.3% of the NGT group underwent surgery.For recurrent adhesive bowel obstruction,ileus tube was also significantly more effective than NGT (95.8% vs 31.6%).In the ileus tube group,the drainage output on the first day and the length of hospital stay were significantly different depending on the treatment success or failure (P < 0.05).The abdominal radiographic improvement was correlated with whether or not the patient underwent surgery.CONCLUSION:Ileus tube can be used for adhesive small bowel obstruction.Endoscopic placement of the ileus tube is convenient and worthy to be promoted despite the potential risks.

  15. 14 CFR 23.1323 - Airspeed indicating system.

    Science.gov (United States)

    2010-01-01

    ... with flaps extended. (c) The design and installation of each airspeed indicating system must provide... respective pitot tubes must be far enough apart to avoid damage to both tubes in a collision with a bird....

  16. Flux-Tube Formation and Holographic Tunneling

    CERN Document Server

    Gorsky, A S

    2008-01-01

    We consider correlator of two concentric Wilson loops, a small and large ones related to the problem of flux-tube formation. There are three mechanisms which can contribute to the connected correlator and yield different dependences on the radius of the small loop. The first one is quite standard and concerns exchange by supergravity modes. We also consider a novel mechanism when the flux-tube formation is described by a barrier transition in the string language, dual to the field-theoretic formulation of Yang-Mills theories. The most interesting possibility within this approach is resonant tunneling which would enhance the correlator of the Wilson loops for particular geometries. The third possibility involves exchange by a dyonic string supplied with the string junction. We introduce also t'Hooft and composite dyonic loops as probes of the flux tube. Implications for lattice measurements are briefly discussed.

  17. 92 K thermoacoustically driven pulse tube refrigerator

    Institute of Scientific and Technical Information of China (English)

    TANG Ke; CHEN Guobang; JIN Tao; KONG Bo; BAO Rui; QIU Limin; GAN Zhihua

    2004-01-01

    @@ A thermoacoustic prime mover, instead of a mechanical compressor, was firstly proposed in 1990 by Radebaugh and Swift et al. to drive a pulse tube refrigerator [1]. The so-called thermoacoustically driven pulse tube refrigerator (TADPTR) has a number of advantages. First,it is characterized by its long-term stable operation for it has no moving components. Besides, solar energy and waste fuel gas can be adopted as its driving source. Utilization of low-grade energy not only improves its overall thermal efficiency, but also is most attractively applicable to the case which is short of electricity but abundant in heat energy. The potential applications, such as thermoacoustic natural gas liquefier, are under development[2].It burns part of natural gas to drive a pulse tube refrigerator whose cooling capacity is then used to liquefy the rest natural gas.

  18. Ice formation around isothermal radial finned tubes

    Energy Technology Data Exchange (ETDEWEB)

    Ismail, K.A.R.; Henriquez, J.R.; Moura, L.F.M.; Ganzarolli, M.M. [UNICAMP-FEM-DETF, Campinas (Brazil)

    2000-04-01

    The present study presents a thermal numerical model for the solidification of Phase Change Material around a radially finned tube with a constant wall temperature. The model is based upon a pure conduction formulation and the enthalpy method. The finite difference approach and the alternating direction implicit scheme are used to discretize the system of equations and the associated boundary, initial and final conditions. Numerical experiments were realized to optimise the numerical code. Numerical simulations were performed to investigate the effects, of the number of fins, fin thickness, fin material, aspect ratio of the tube arrangement and the tube wall temperature. Graphical results were presented, discussed and equations relating the effect of each of the variables on the time for complete solidification are also presented. (author)

  19. Non-Uniform Tube Representation of Proteins

    DEFF Research Database (Denmark)

    Hansen, Mikael Sonne

    Treating the full protein structure is often neither computationally nor physically possible. Instead one is forced to consider various reduced models capturing the properties of interest. Previous work have used tubular neighborhoods of the C-alpha backbone. However, assigning a unique radius...... might not correctly capture volume exclusion - of crucial importance when trying to understand a protein's 3d-structure. We propose a new reduced model treating the protein as a non-uniform tube with a radius reflecting the positions of atoms. The tube representation is well suited considering X......-ray crystallographic resolution ~ 3Å while a varying radius accounts for the different sizes of side chains. Such a non-uniform tube better captures the protein geometry and has numerous applications in structural/computational biology from the classification of protein structures to sequence-structure prediction....

  20. Non-uniform tube representation of proteins

    DEFF Research Database (Denmark)

    Hansen, Mikael Sonne

    Treating the full protein structure is often neither computationally nor physically possible. Instead one is forced to consider various reduced models capturing the properties of interest. Previous work have used tubular neighborhoods of the C-alpha backbone. However, assigning a unique radius...... might not correctly capture volume exclusion - of crucial importance when trying to understand a proteins $3$d-structure. We propose a new reduced model treating the protein as a non-uniform tube with a radius reflecting the positions of atoms. The tube representation is well suited considering X......-ray crystallographic resolution ~ 3Å while a varying radius accounts for the different sizes of side chains. Such a non-uniform tube better capture the protein geometry and has numerous applications in structural/computational biology from the classification of protein structures to sequence-structure prediction....

  1. Non-uniform tube representation of proteins

    DEFF Research Database (Denmark)

    Hansen, Mikael Sonne

    might not correctly capture volume exclusion - of crucial importance when trying to understand a proteins $3$d-structure. We propose a new reduced model treating the protein as a non-uniform tube with a radius reflecting the positions of atoms. The tube representation is well suited considering X......Treating the full protein structure is often neither computationally nor physically possible. Instead one is forced to consider various reduced models capturing the properties of interest. Previous work have used tubular neighborhoods of the C-alpha backbone. However, assigning a unique radius......-ray crystallographic resolution ~ 3Å while a varying radius accounts for the different sizes of side chains. Such a non-uniform tube better capture the protein geometry and has numerous applications in structural/computational biology from the classification of protein structures to sequence-structure prediction....

  2. Non-Uniform Tube Representation of Proteins

    DEFF Research Database (Denmark)

    Hansen, Mikael Sonne

    might not correctly capture volume exclusion - of crucial importance when trying to understand a protein's 3d-structure. We propose a new reduced model treating the protein as a non-uniform tube with a radius reflecting the positions of atoms. The tube representation is well suited considering X......Treating the full protein structure is often neither computationally nor physically possible. Instead one is forced to consider various reduced models capturing the properties of interest. Previous work have used tubular neighborhoods of the C-alpha backbone. However, assigning a unique radius......-ray crystallographic resolution ~ 3Å while a varying radius accounts for the different sizes of side chains. Such a non-uniform tube better captures the protein geometry and has numerous applications in structural/computational biology from the classification of protein structures to sequence-structure prediction....

  3. Stretching a Semiflexible Polymer in a Tube

    Directory of Open Access Journals (Sweden)

    Runhua Li

    2016-09-01

    Full Text Available How the statistical behavior of semiflexible polymer chains may be affected by force stretching and tube confinement is a classical unsolved problem in polymer physics. Based on the Odijk deflection theory and normal mode decomposition in terms of Fourier expansion, we have derived a new compact formula for the extension of a wormlike chain of finite length strongly confined in a tube and simultaneously stretched by an external force. We have also suggested a new deflection length, which together with the force-extension relation is valid for a very extended range of the tube-diameter/persistence-length ratio comparing to the classic Odijk theory. The newly derived formula has no adjustable fitting parameters for the whole deflection regime; in contrast, the classic Odijk length needs different prefactors to fit the free energy and average extension, respectively. Brownian dynamics simulations based on the Generalized Bead-Rod (GBR model were extensively performed, which justified the theoretical predictions.

  4. Incarcerated Femoral Hernia Containing Ipsilateral Fallopian Tube

    Directory of Open Access Journals (Sweden)

    Stefanos Atmatzidis

    2010-01-01

    Full Text Available Femoral hernias are more common in women and lead to a substantial higher rate for an emergency operation, due to strangulation. Incarcerated femoral hernia with fallopian tube as a content is an extremely rare condition. A 20-year-old woman presented to the emergency department complaining of a 6-day right groin swelling, which became painful and tender to palpation during the last 48 hours. Preoperative ultrasonography detected an oedematous hernia sac, above the femoral vessels, suggesting the presence of an incarcerated femoral hernia. The patient eventually underwent emergency surgery and the diagnosis of a strangulated femoral hernia sac, containing fallopian tube, was established. No resection of the uterine tube was performed and the hernia was repaired with polypropylene plug. The postoperative period was uneventful and the woman was discharged on the second postoperative day.

  5. 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.

  6. QUANTITATIVE ANALYSIS OF DRAWING TUBES MICROSTRUCTURE

    Directory of Open Access Journals (Sweden)

    Maroš Martinkovič

    2009-05-01

    Full Text Available Final properties of forming pieces are affected by production, at first conditions of mechanical working. Application of stereology methods to statistic reconstruction of three-dimensional plastic deformed material structure by bulk forming led to detail analysis of material structure changes. The microstructure of cold drawing tubes from STN 411353 steel was analyzed. Grain boundaries orientation was measured on perpendicular and parallel section of tubes with different degree of deformation. Macroscopic deformation leads to grain boundaries deformation and these ones were compared.

  7. Wave heating in magnetic flux tubes

    Science.gov (United States)

    Kalkofen, Wolfgang

    1990-01-01

    The bright chromosphere in the quiet sun is confined to magnetic elements (flux tubes), which are located in the interior of the supergranulation cells and within the network that surrounds the cells. The paper discusses the heating of the gas in the magnetic elements of the cell interior. These intranetwork flux tubes are closely associated with bright points, which are heated by large-amplitude compressive waves with periods near the acoustic cutoff that travel outward from the photosphere and dissipate their energy in the chromosphere. The energy flux of these long-period waves appears to be sufficient for the heating of the low and middle chromosphere in the bright points.

  8. 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.

  9. Constructing Hybrid Baryons with Flux Tubes

    CERN Document Server

    Capstick, Simon; Capstick, Simon; Page, Philip R.

    1999-01-01

    Hybrid baryon states are described in quark potential models as having explicit excitation of the gluon degrees of freedom. Such states are described in a model motivated by the strong coupling limit of Hamiltonian lattice gauge theory, where three flux tubes meeting at a junction play the role of the glue. The adiabatic approximation for the quark motion is used, and the flux tubes and junction are modeled by beads which are attracted to each other and the quarks by a linear potential, and vibrate in various string modes. Quantum numbers and estimates of the energies of the lightest hybrid baryons are provided.

  10. Condensate Accretion in Shock Tube's Expansion Fan

    Science.gov (United States)

    Mezonlin, Ephrem-Denis; DeSilva, Upul P.; Hunte, F.; Johnson, Joseph A., III

    1997-01-01

    It has been shown that turbulence and temperature influence the droplet sizes in expansion fan induced condensation by studying the Rayleigh scattering from one port in our shock tube's test section. We have modified our set-up so as to allow, using two ports, the real time measurement of the influence of turbulence and temperature on the rate at which these droplets grow. To do this, we looked at the Rayleigh scattering from two different ports for ten Reynolds numbers at five different temperatures. We modeled the time of flight of droplets, using the equations of one-dimensional gas dynamics and the measured shock wave speed in shock tube's driven section.

  11. CHARACTERIZATION OF ADDITIVE MANUFACTURING FOR PROCESS TUBING

    Energy Technology Data Exchange (ETDEWEB)

    Korinko, John S. [Savannah River National Laboratory (SRNL); BobbittIII, John T. [Savannah River National Laboratory (SRNL); Morgan, Michael J. [Savannah River National Laboratory (SRNL); Reigel, Marissa [Savannah River National Laboratory (SRNL); List III, Frederick Alyious [ORNL; Babu, Suresh S. [University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL)

    2016-01-01

    Additive Manufacturing has garnered significant levels of interest in recent years as a primary manufacturing method. While the general technology has been around for over 20 years, with increased computing capacity, higher powered directed energy sources, e.g., lasers and electron beams, it is coming of age as a viable technique for high value added, low production quantity components. The Savannah River National Laboratory is interested in AM as a technique to build hydrogen isotope separation components called Thermal Cycling Absorption Process (TCAP) columns. The TCAP operates from cryogenic to moderate temperatures in a cyclic manner and is a pressure boundary. The current technique for fabricating TCAP columns is to form a flat coil of 0.375 to 0.5 inch diameter tube and braze two coils together. During the brazing operation, the two nested coils often move and this movement results in gaps between the coils. Since one coil contains the working fluid, i.e., liquid nitrogen, and the other the process fluid, hydrogen isotopes, these gaps result in poor heat transfer. Additive manufacturing is being explored as a replacement technology since the adjacent tubes can be fabricated simultaneously and in intimate contact and they can also share a common wall to improve heat transfer. AM allows designers to develop unique tube structures that overcome several of the shortcomings of the coil and braze technique, such as the braze gap in fabrication and slow cooling during operation. Simple test samples with various internal geometries were designed and built from Type 316L stainless steel using a laser powder bed process. Three test article geometries that were built include a simple tube, a pair of stacked tubes, and a tube partially surrounded by two kidney shaped tubes with cooling fins that would extend into the process fluid, these tube sections incorporated thermowells or heat trace channels, selectively. The test samples will be subjected to heat transfer

  12. Self-assembling segmented coiled tubing

    Energy Technology Data Exchange (ETDEWEB)

    Raymond, David W.

    2016-09-27

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

  13. Arrested Bubble Rise in a Narrow Tube

    Science.gov (United States)

    Lamstaes, Catherine; Eggers, Jens

    2016-06-01

    If a long air bubble is placed inside a vertical tube closed at the top it can rise by displacing the fluid above it. However, Bretherton found that if the tube radius, R, is smaller than a critical value Rc=0.918 ℓ_c , where ℓ_c=√{γ /ρ g} is the capillary length, there is no solution corresponding to steady rise. Experimentally, the bubble rise appears to have stopped altogether. Here we explain this observation by studying the unsteady bubble motion for Rarrested motion.

  14. Ovalization of Tubes Under Bending and Compression

    Science.gov (United States)

    Demer, L J; Kavanaugh, E S

    1944-01-01

    An empirical equation has been developed that gives the approximate amount of ovalization for tubes under bending loads. Tests were made on tubes in the d/t range from 6 to 14, the latter d/t ratio being in the normal landing gear range. Within the range of the series of tests conducted, the increase in ovalization due to a compression load in combination with a bending load was very small. The bending load, being the principal factor in producing the ovalization, is a rather complex function of the bending moment, d/t ratio, cantilever length, and distance between opposite bearing faces. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-06-01

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

  16. Replacement of a feeding tube through the gastric tube in patients after esophagectomy with retrosternal reconstruction.

    Science.gov (United States)

    Ikeda, Yoshifumi; Morita, Naomi

    2009-04-01

    We present our technique of endoscopic replacement of the jejunostomy through the stomach conduit in patients after esophagectomy with retrosternal reconstruction. After an upper gastrointestinal tract endoscopy was performed, the stomach conduit was sufficiently inflated with air and the site of the previously removed gastric tube was confirmed by the puncture using 23 G needle. After an approximately 6-mm incision was made under local anesthesia, a 4-mm peel-off introducer sheath was advanced into the stomach conduit under endoscopic control. A 3-mm jejunostomy tube was inserted through the sheath and placed into the jejunum using the endoscopic guidance. Using endoscopy, the jejunostomy tube was confirmed to be placed without bending. Between 1998 and 2006, subtotal esophagectomy with retrosternal cervical esophagogastrostomy was performed in 48 patients. All patients were inserted with at least either jejunostomy tube or decompression tube through the stomach conduit. Among them, 11 patients (23%) were performed percutaneous replacement jejunostomy through the stomach conduit. There were 9 men and 2 women whose mean age was 67 years (range: 59 to 76 y). Replacement of the jejunostomy tube was successful in all patients. The procedure required about 30 minutes. There were no deaths and no procedural complications. After 24 hours, the tube was used for enteral feeding. No late complication occurred in our cases. We believe that the endoscopic percutaneous approach described in this report is safe and effective in patients after esophagectomy with retrosternal reconstruction.

  17. Performance of pressure tubes in CANDU reactors

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-06-15

    The pressure tubes in CANDU reactors typically operate for times up to about 30 years prior to refurbishment. The in-reactor performance of Zr-2.5Nb pressure tubes has been evaluated by sampling and periodic inspection. This paper describes the behavior and discusses the factors controlling the behaviour of these components. The Zr–2.5Nb pressure tubes are nominally extruded at 815{sup o}C, cold worked nominally 27%, and stress relieved at 400 {sup o}C for 24 hours, resulting in a structure consisting of elongated grains of hexagonal close-packed alpha-Zr, partially surrounded by a thin network of filaments of body-centred-cubic beta-Zr. These beta-Zr filaments are meta-stable and contain about 20% Nb after extrusion. The stress-relief treatment results in partial decomposition of the beta-Zr filaments with the formation of hexagonal close-packed alpha-phase particles that are low in Nb, surrounded by a Nb-enriched beta-Zr matrix. The material properties of pressure tubes are determined by variations in alpha-phase texture, alpha-phase grain structure, network dislocation density, beta-phase decomposition, and impurity concentration that are a function of manufacturing variables. The pressure tubes operate at temperatures between 250 {sup o}C and 310 {sup o}C with coolant pressures up to about 11 MPa in fast neutron fluxes up to 4 x 10{sup 17} n·m{sup -2}·s{sup -1} (E > 1 MeV) and the properties are modified by these conditions. The properties of the pressure tubes in an operating reactor are therefore a function of both manufacturing and operating condition variables. The ultimate tensile strength, fracture toughness, and delayed hydride-cracking properties (velocity (V) and threshold stress intensity factor (K{sub IH})) change with irradiation, but all reach a nearly limiting value at a fluence of less than 10{sup 25} n·m{sup -2} (E > 1 MeV). At this point the ultimate tensile strength is raised about 200 MPa, toughness is reduced by about 50%, V increases

  18. Characterization of ultrafine-grained aluminum tubes processed by Tube Cyclic Extrusion–Compression (TCEC)

    Energy Technology Data Exchange (ETDEWEB)

    Babaei, A., E-mail: A_babaei@ut.ac.ir; Mashhadi, M.M.

    2014-09-15

    Tube Cyclic Extrusion–Compression as a novel severe plastic deformation technique for tubes was utilized for processing ultrafine grained 1050 aluminum alloy for the first time. In this method, aluminum tube is fully constrained and deformed between mandrel and chamber with a small neck zone. The material deformation during Tube Cyclic Extrusion–Compression processing analyzed and the grain refinement mechanism were described. The capability of Tube Cyclic Extrusion–Compression in grain refinement of the aluminum alloy was demonstrated by transmission electron microscopy observations and X-ray diffraction line profile analysis. The micrographs of the evolved microstructure show grain size of 850 nm and 550 nm after the first and second processing cycles of Tube Cyclic Extrusion–Compression, respectively. Mechanical properties of the initial and processed specimens were extracted from ring-hoop tensile tests. The documented results confirm grain refinement by showing remarkable increase in the yield and ultimate strengths. The main increase in strength and decrease in elongation take place after the first cycle. The microhardness assessments illustrate increase from the initial value of 29 Hv to 44 and 49 Hv respectively after the first and second cycles of Tube Cyclic Extrusion–Compression. There is a good homogeneity in peripheral microhardness and microhardness across the tube thickness. - Highlights: • Tubes of AA1050 for the first time were successfully SPD processed by TCEC. • The grain size was refined to 550 nm after two cycles of TCEC. • Notable increase in the strength and decrease in the elongation were documented. • The microhardness increased to 49 Hv from the initial value of 29 Hv. • Good homogeneity in the microhardness distribution was recorded.

  19. 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

  20. Tube Thoracostomy: A Review for the Interventional Radiologist

    Science.gov (United States)

    Hogg, Jeremy R.; Caccavale, Michael; Gillen, Benjamin; McKenzie, Gavin; Vlaminck, Jay; Fleming, Chad J.; Stockland, Andrew; Friese, Jeremy L.

    2011-01-01

    Small-caliber tube thoracostomy is a valuable treatment for various pathologic conditions of the pleural space. Smaller caliber tubes placed under image guidance are becoming increasingly useful in numerous situations, are less painful than larger surgical tubes, and provide more accurate positioning when compared with tubes placed without image guidance. Basic anatomy and physiology of the pleural space, indications, and contraindications of small caliber tube thoracostomy, techniques for image-guided placement, complications and management of tube thoracostomy, and fundamental principles of pleurodesis are discussed in this review. PMID:22379275

  1. Když se řekne YouTube

    OpenAIRE

    Voců, Ondřej

    2011-01-01

    This article describes basic characteristics of YouTube portal, explains its importance and provided services. The first part of this article is applied to basic characteristics of YouTube portal, the second part deals with processes related to videos on YouTube. YouTube users, YouTube partners and projects are mainspring of the third part of this article. Special subchapter outlines possibilites of YouTube in relation to information studies and librarianship. At the end of the fourth chapter...

  2. CFD Studies on Multi Lead Rifled [MLR] Boiler Tubes

    Directory of Open Access Journals (Sweden)

    Dr T C Mohankumar

    2013-09-01

    Full Text Available This paper reports the merits of multi lead rifled [MLR] tubes in vertical water tube boiler using CFD tool. Heat transfer enhancement of MLR tubes was mainly taken in to consideration. Performance of multi lead rifled tube was studied by varying its influencing geometrical parameter like number of rifling, height of rifling, length of pitch of rifling for a particular length. The heat transfer analysis was done at operating conditions of an actual coal fired water tube boiler situated at Apollo Tyres LTD, Chalakudy, India for saturated process steam production. The results showed that the heat transfer increased when compared with existing inner plane wall water tubes.

  3. [Intubation with a tube exchanger on an intubation trainer. Influence of tube tip position on successful intubation].

    Science.gov (United States)

    Kemper, M; Haas, T; Imach, S; Weiss, M

    2014-07-01

    Securing the airway using a tube exchanger catheter is an important and useful technique in anesthesia. Its success is mainly hampered by tube tip impingement of laryngeal structures. Advancing the tracheal tube along its normal curvature via a tube exchanger catheter has a high risk of tube tip impingement mainly of right laryngeal structures. The authors achieved successful clinical experience by rotating the tracheal tube 90° anticlockwise (ventral tube tip position) before railroading the tube via a tube exchanger catheter or a fiber optic bronchoscope through the larynx. The aim of the study was to investigate the influence of the tracheal tube tip position while intubating an airway trainer over a tube exchange catheter. Volunteer anesthetists with varying years of professional experience were asked to intubate an intubation mannequin (Laerdal Airway Management Trainer) using the orotracheal route with an established tube exchange catheter (Cook Airway Exchange Catheter, 11F). Two different brands of tracheal tubes (Rüsch and Covidien, ID 7.0 mm) were used in a randomized order, each with the tracheal tube tip at first positioned right (90°), then ventrally (0°), left (270°) and finally dorsally (180°), resulting in eight intubation attempts for each participant. To ensure the correct tube tip position the tube was withdrawn before every intubation attempt until the tube tip position was visualized. The oropharnyx, larynx, trachea and tube were sufficiently lubricated with silicon spray (Rüsch Silikospray). The tube and airway exchange catheter size selection were made according to the clinical trial of Loudermilk et al. Successful endotracheal intubation without resistance was recorded for each tube tip position and tracheal tube brand. In total 20 anesthetists (13 consultants and 7 residents) with a median of 9.5 years (range 3-37 years) of professional experience participated in the study. Overall 160 intubation attempts were performed, 2

  4. YouTube and Video Quizzes

    Directory of Open Access Journals (Sweden)

    Kevin YEE

    2010-04-01

    Full Text Available The Internet sensation YouTube (http://www.youtube.com has become such a force online that it was estimated in 2006 to account for a full tenth of the bandwidth by the entire Internet in the United States (WebProNews, 2007, and to use as much bandwidth in 2007 as the entire Internet had done in 2000 (Carter, 2008. Like many technological tools created with entertainment or profit in mind, YouTube can now be easily and usefully adopted by instructors for educational purposes, and indeed many professors use YouTube in their classroom teaching already (Brooks, 2000. This is especially true for passive uses of YouTube; watching videos that are already online and using them in the classroom experience to support a concept and provide another mechanism for students to connect with the topics. It is fruitful to consider Bloom's Taxonomy of Educational Objectives (Bloom & Krathwohl, 1956 when employing video or any media in the classroom to maximize the intentionality of teaching and learning. The use of video for demonstration or modeling corresponds well to Blooms levels of Knowledge, Comprehension, and Application; while case studies offer a chance to demonstrate Analysis and Synthesis, and perhaps even Evaluation, when comparing a video to information from a text book or other content.

  5. When to Remove a Chest Tube.

    Science.gov (United States)

    Novoa, Nuria M; Jiménez, Marcelo F; Varela, Gonzalo

    2017-02-01

    Despite the increasing knowledge about the pleural physiology after lung resection, most practices around chest tube removal are dictated by personal preferences and experience. This article discusses recently published data on the topic and suggests opportunities for further investigation and future improvements. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Stress-Assisted Corrosion in Boiler Tubes

    Energy Technology Data Exchange (ETDEWEB)

    Preet M Singh; Steven J Pawel

    2006-05-27

    A number of industrial boilers, including in the pulp and paper industry, needed to replace their lower furnace tubes or decommission many recovery boilers due to stress-assisted corrosion (SAC) on the waterside of boiler tubes. More than half of the power and recovery boilers that have been inspected reveal SAC damage, which portends significant energy and economic impacts. The goal of this project was to clarify the mechanism of stress-assisted corrosion (SAC) of boiler tubes for the purpose of determining key parameters in its mitigation and control. To accomplish this in-situ strain measurements on boiler tubes were made. Boiler water environment was simulated in the laboratory and effects of water chemistry on SAC initiation and growth were evaluated in terms of industrial operations. Results from this project have shown that the dissolved oxygen is single most important factor in SAC initiation on carbon steel samples. Control of dissolved oxygen can be used to mitigate SAC in industrial boilers. Results have also shown that sharp corrosion fatigue and bulbous SAC cracks have similar mechanism but the morphology is different due to availability of oxygen during boiler shutdown conditions. Results are described in the final technical report.

  7. "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.

  8. Wave propagation in spatially modulated tubes.

    Science.gov (United States)

    Ziepke, A; Martens, S; Engel, H

    2016-09-07

    We investigate wave propagation in rotationally symmetric tubes with a periodic spatial modulation of cross section. Using an asymptotic perturbation analysis, the governing quasi-two-dimensional reaction-diffusion equation can be reduced into a one-dimensional reaction-diffusion-advection equation. Assuming a weak perturbation by the advection term and using projection method, in a second step, an equation of motion for traveling waves within such tubes can be derived. Both methods predict properly the nonlinear dependence of the propagation velocity on the ratio of the modulation period of the geometry to the intrinsic width of the front, or pulse. As a main feature, we observe finite intervals of propagation failure of waves induced by the tube's modulation and derive an analytically tractable condition for their occurrence. For the highly diffusive limit, using the Fick-Jacobs approach, we show that wave velocities within modulated tubes are governed by an effective diffusion coefficient. Furthermore, we discuss the effects of a single bottleneck on the period of pulse trains. We observe period changes by integer fractions dependent on the bottleneck width and the period of the entering pulse train.

  9. Flow induced pulsations generated in corrugated tubes

    NARCIS (Netherlands)

    Belfroid, S.P.C.; Swindell, R.; Tummers, R.

    2008-01-01

    Corrugated tubes can produce a tonal noise when used for gas transport, for instance in the case of flexible risers. The whistling sound is generated by shear layer instability due to the boundary layer separation at each corrugation. This whistling is examined by investigating the frequency, amplit

  10. Flow induced pulsations caused by corrugated tubes

    NARCIS (Netherlands)

    Shatto, D.P.; Belfroid, S.P.C.; Peters, M.C.A.M.

    2007-01-01

    Corrugated tubes can produce a tonal noise when used for gas transport, for instance in the case of flexible risers. The whistling sound is generated by shear layer instability due to the boundary layer separation at each corrugation. This whistling is examined by investigating the frequency, amplit

  11. Steam generator tube integrity flaw acceptance criteria

    Energy Technology Data Exchange (ETDEWEB)

    Cochet, B. [FRAMATOME, Paris la Defense (France)

    1997-02-01

    The author discusses the establishment of a flaw acceptance criteria with respect to flaws in steam generator tubing. The problem is complicated because different countries take different approaches to the problem. The objectives in general are grouped in three broad areas: to avoid the unscheduled shutdown of the reactor during normal operation; to avoid tube bursts; to avoid excessive leak rates in the event of an accidental overpressure event. For each degradation mechanism in the tubes it is necessary to know answers to an array of questions, including: how well does NDT testing perform against this problem; how rapidly does such degradation develop; how well is this degradation mechanism understood. Based on the above information it is then possible to come up with a policy to look at flaw acceptance. Part of this criteria is a schedule for the frequency of in-service inspection and also a policy for when to plug flawed tubes. The author goes into a broad discussion of each of these points in his paper.

  12. Regulation of Pollen Tube Growth by Transglutaminase

    Directory of Open Access Journals (Sweden)

    Giampiero Cai

    2013-03-01

    Full Text Available In pollen tubes, cytoskeleton proteins are involved in many aspects of pollen germination and growth, from the transport of sperm cells to the asymmetrical distribution of organelles to the deposition of cell wall material. These activities are based on the dynamics of the cytoskeleton. Changes to both actin filaments and microtubules are triggered by specific proteins, resulting in different organization levels suitable for the different functions of the cytoskeleton. Transglutaminases are enzymes ubiquitous in all plant organs and cell compartments. They catalyze the post-translational conjugation of polyamines to different protein targets, such as the cytoskeleton. Transglutaminases are suggested to have a general role in the interaction between pollen tubes and the extracellular matrix during fertilization and a specific role during the self-incompatibility response. In such processes, the activity of transglutaminases is enhanced, leading to the formation of cross-linked products (including aggregates of tubulin and actin. Consequently, transglutaminases are suggested to act as regulators of cytoskeleton dynamics. The distribution of transglutaminases in pollen tubes is affected by both membrane dynamics and the cytoskeleton. Transglutaminases are also secreted in the extracellular matrix, where they may take part in the assembly and/or strengthening of the pollen tube cell wall.

  13. Enrichment Monitor for 235U Fuel Tubes

    Energy Technology Data Exchange (ETDEWEB)

    Winn, W.G.

    2001-08-22

    This report describes the performance of this prototype y-monitor of 235 Uranium enrichment. In this proposed method y-rates associated with 235U and 232U are correlated with enrichment. Instrumentation for appraising fuel tubes with this method has been assembled and tested.

  14. Aspergillus DNA contamination in blood collection tubes

    Science.gov (United States)

    Harrison, Elizabeth; Stahlberger, Thomas; Whelan, Ruth; Sugrue, Michele; Wingard, John R.; Alexander, Barbara D.; Follett, Sarah A.; Bowyer, Paul; Denning, David W.

    2010-01-01

    Fungal PCR-based diagnostic methods are at risk of contamination. Sample collection containers were investigated for fungal DNA contamination using real-time PCR assays. Up to 18% of blood collection tubes were contaminated with fungal DNA, probably A. fumigatus. Lower proportions of contamination in other vessels were observed. PMID:20638611

  15. 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.

  16. 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.

  17. The power of YouTube

    Science.gov (United States)

    Moriarty, Philip

    2014-03-01

    As one of the presenters of the hugely successful Sixty Symbols series of YouTube science videos, Philip Moriarty describes his experiences in front of the camera and how they have transformed his ideas about bringing physics to wider audiences.

  18. YouTube in the Science Classroom

    Science.gov (United States)

    Everhart, Jerry

    2009-01-01

    YouTube makes it possible for teachers to capitalize on children's insatiable appetite for visually stimulating learning. Some of these videos attain "viral" status, getting passed on from person to person and by links on other sites. Not only are these popular videos viral, but developing one's own content and posting it for the world's access is…

  19. YouTube as a Participatory Culture

    Science.gov (United States)

    Chau, Clement

    2010-01-01

    There is an explosion of youth subscriptions to original content-media-sharing Web sites such as YouTube. These Web sites combine media production and distribution with social networking features, making them an ideal place to create, connect, collaborate, and circulate. By encouraging youth to become media creators and social networkers, new…

  20. YouTube: Educational Potentials and Pitfalls

    Science.gov (United States)

    Jones, Troy; Cuthrell, Kristen

    2011-01-01

    The instructional potential of video technology in the classroom is promising, especially in light of the 21st Century Learning Framework (Siegle, 2009). Studies show positive gains in student outcomes as a result of the integration of video technology in instruction. This article explores potential uses of YouTube as an instructional aid in…

  1. Wave propagation in spatially modulated tubes

    Science.gov (United States)

    Ziepke, A.; Martens, S.; Engel, H.

    2016-09-01

    We investigate wave propagation in rotationally symmetric tubes with a periodic spatial modulation of cross section. Using an asymptotic perturbation analysis, the governing quasi-two-dimensional reaction-diffusion equation can be reduced into a one-dimensional reaction-diffusion-advection equation. Assuming a weak perturbation by the advection term and using projection method, in a second step, an equation of motion for traveling waves within such tubes can be derived. Both methods predict properly the nonlinear dependence of the propagation velocity on the ratio of the modulation period of the geometry to the intrinsic width of the front, or pulse. As a main feature, we observe finite intervals of propagation failure of waves induced by the tube's modulation and derive an analytically tractable condition for their occurrence. For the highly diffusive limit, using the Fick-Jacobs approach, we show that wave velocities within modulated tubes are governed by an effective diffusion coefficient. Furthermore, we discuss the effects of a single bottleneck on the period of pulse trains. We observe period changes by integer fractions dependent on the bottleneck width and the period of the entering pulse train.

  2. New camera tube improves ultrasonic inspection system

    Science.gov (United States)

    Berger, H.; Collis, W. J.; Jacobs, J. E.

    1968-01-01

    Electron multiplier, incorporated into the camera tube of an ultrasonic imaging system, improves resolution, effectively shields low level circuits, and provides a high level signal input to the television camera. It is effective for inspection of metallic materials for bonds, voids, and homogeneity.

  3. YouTube as a Participatory Culture

    Science.gov (United States)

    Chau, Clement

    2010-01-01

    There is an explosion of youth subscriptions to original content-media-sharing Web sites such as YouTube. These Web sites combine media production and distribution with social networking features, making them an ideal place to create, connect, collaborate, and circulate. By encouraging youth to become media creators and social networkers, new…

  4. Analysis of Manufacturing Bimetallic Tubes by the Cold Drawing Process

    Directory of Open Access Journals (Sweden)

    Halaczek D.

    2016-03-01

    Full Text Available Drawing processes apply to obtain the bimetallic tubes from the different metals and alloys, combined in the solid state, which significantly affects the specificity of this process. The manufacturing of bimetallic tubes by drawing process depends on many factors which include: preparation of the surface of materials joined in the solid state, the geometric parameters of the working tool, technological parameters of the drawing process (drawing speed, type of lubricant, the use of back pull etc.. Generally, the cold drawing process of producing the bimetallic tubes refers to metals which have high ductility (copper, aluminum, etc.. The tube sinking (tube drawing without a mandrel of bimetallic tubes together with joining them at the interface of the two metal in the solid-state is applied for tubes of the diameter range between 6 to 20 mm and based on of the reducing the diameter of the tube. However, a slight increase of wall thickness ca. 0.05 ÷ 0.10 mm can appear, which is not dangerous phenomenon in case of producing the bimetallic tubes by joining in the solid-state. The aim of the research was to investigate the technology of tubes drawing process from non-ferrous metal, drawing process of bimetallic tubes and the production of bimetallic tubes in layers composition: cooper Cu-ETP - brass CuZn37 and CuZn37 brass - copper Cu-ETP in the tube sinking process. The research program included: production of bimetallic tubes with a different composition (Cu- ETP-CuZn37 and CuZn37-Cu-ETP and a different percentage of the cross-section components; analysis of changes of tube wall thickness and the layer composition of the bimetallic tube, based on measurements on the workshop microscope; analysis of the material flow in the process of the bimetallic tubes production based on the measurements results of a profilograph CP-200.

  5. 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.

  6. Future ultra-speed tube-flight

    Science.gov (United States)

    Salter, Robert M.

    1994-05-01

    Future long-link, ultra-speed, surface transport systems will require electromagnetically (EM) driven and restrained vehicles operating under reduced-atmosphere in very straight tubes. Such tube-flight trains will be safe, energy conservative, pollution-free, and in a protected environment. Hypersonic (and even hyperballistic) speeds are theoretically achievable. Ultimate system choices will represent tradeoffs between amoritized capital costs (ACC) and operating costs. For example, long coasting links might employ aerodynamic lift coupled with EM restraint and drag make-up. Optimized, combined EM lift, and thrust vectors could reduce energy costs but at increased ACC. (Repulsive levitation can produce lift-over-drag l/d ratios a decade greater than aerodynamic), Alternatively, vehicle-emanated, induced-mirror fields in a conducting (aluminum sheet) road bed could reduce ACC but at substantial energy costs. Ultra-speed tube flight will demand fast-acting, high-precision sensors and computerized magnetic shimming. This same control system can maintain a magnetic 'guide way' invariant in inertial space with inertial detectors imbedded in tube structures to sense and correct for earth tremors. Ultra-speed tube flight can complete with aircraft for transit time and can provide even greater passenger convenience by single-model connections with local subways and feeder lines. Although cargo transport generally will not need to be performed at ultra speeds, such speeds may well be desirable for high throughput to optimize channel costs. Thus, a large and expensive pipeline might be replaced with small EM-driven pallets at high speeds.

  7. Applications of a thru-tubing cement retainer conveyed on coiled tubing

    Energy Technology Data Exchange (ETDEWEB)

    Willems, T. (Baker Oil Tools, Houston, TX (Canada)); Tudor, E.H. (Canadian Fracmaster Ltd., Calgary, AB (Canada)); Cooke, J.A. (Chevron Canada Resources, Fox Creek, AB (Canada))

    1994-01-01

    A thru-tubing inflatable permanent cement retainer has been developed to selectively squeeze cement without pulling the production tubing or killing the well. The system has been run successfully on coiled tubing through 73 mm tubing and set in 177.8 mm casing. Due to the performance limitations of the inflatable cement retainer, unconventional methods were used to inflate the tool and perform a hesitation cement squeeze. Equipment and procedures used to selectively squeeze off water production in two wells in the Kaybob south field in central Alberta are described. Both wells are gas producers from a sour, underpressured carbonate formation. In order to control hydrostatic pressure and obtain the squeeze, nitrogen gas was used as the circulation and displacement medium. Workover design considerations, cement retainer differential pressure ratings, depth control, inflation procedure, cement slurry design, cement squeeze operation, and job procedure are described. 2 refs., 3 figs.

  8. Method for Improving Transverse Wall Thickness Precision of Seamless Steel Tube Based on Tube Rotation

    Institute of Scientific and Technical Information of China (English)

    Yong-zheng JIANG; Hua-ping TANG

    2015-01-01

    The tube rotation method (TRM) refers to the rotational movement of steel tube about its axis as well as translation in rolling direction in stretch reducing rolling process. The inlfuence of the TRM on transverse wall thickness precision of seamless steel tube was studied. Thickness distribution of the TRM was obtained by superimposing the thickened amount of single pass roll-ing. Results show that the TRM can effectively improve the evenness of thickness distribution. In order to analyze the inlfuence mechanism of the TRM, the ifnite element method was adopted to simulate the thickness distribution in stretch reduction process. Results show that the TRM changes the roundtrip lfow between two ifx places of conventional stretch reducing and inhibits the directional accumulation of metal. In addition, the TRM has a correction effect on thickness cusp. All these advantages of the TRM help to improve the transverse wall thickness precision of seamless steel tube.

  9. Characterization of Friction Stir Welded Tubes by Means of Tube Bulge Test

    Science.gov (United States)

    D'Urso, G.; Longo, M.; Giardini, C.

    2011-05-01

    Mechanical properties of friction stir welded joints are generally evaluated by means of conventional tensile test. This testing method might provide insufficient information because maximum strain obtained in tensile test before necking is small; moreover, the application of tensile test is limited when the joint path is not linear or even when the welds are executed on curved surfaces. Therefore, in some cases, it would be preferable to obtain the joints properties from other testing methods. Tube bulge test can be a valid solution for testing circumferential or longitudinal welds executed on tubular workpieces. The present work investigates the mechanical properties and the formability of friction stir welded tubes by means of tube bulge tests. The experimental campaign was performed on tubular specimens having a thickness of 3 mm and an external diameter of 40 mm, obtained starting from two semi-tubes longitudinally friction stir welded. The first step, regarding the fabrication of tubes, was performed combining a conventional forming process and friction stir welding. Sheets in Al-Mg-Si-Cu alloy AA6060 T6 were adopted for this purpose. Plates having a dimension of 225×60 mm were bent (with a bending axis parallel to the main dimension) in order to obtain semi-tubes. A particular care was devoted to the fabrication of forming devices (punch and die) in order to minimize the springback effects. Semi-tubes were then friction stir welded by means of a CNC machine tool. Some preliminary tests were carried out by varying the welding parameters, namely feed rate and rotational speed. A very simple tool having flat shoulder and cylindrical pin was used. The second step of the research was based on testing the welded tubes by means of tube bulge test. A specific equipment having axial actuators with a conical shape was adopted for this study. Some analyses were carried out on the tubes bulged up to a certain pressure level. In particular, the burst pressure and the

  10. A COMPARISON OF HEAT TRANSFER AROUND A SINGLE SERRATED FINNED TUBE AND A PLAIN FINNED TUBE

    Directory of Open Access Journals (Sweden)

    S.R.Mcilwain

    2010-02-01

    Full Text Available With comparable bundle geometry, serrated fin finned tube heat exchangers transfer more heat than plain finned ones. There are believed to be many factors in this behaviour, and this investigation used CFD to examine the heat transfer and fluid flow patterns around the fins to try to understand the magnitude of the differences in the processes. The study is a first step in developing a new theory-based method to predict the performance of serrated fin tube bundles.

  11. A COMPARISON OF HEAT TRANSFER AROUND A SINGLE SERRATED FINNED TUBE AND A PLAIN FINNED TUBE

    OpenAIRE

    2010-01-01

    With comparable bundle geometry, serrated fin finned tube heat exchangers transfer more heat than plain finned ones. There are believed to be many factors in this behaviour, and this investigation used CFD to examine the heat transfer and fluid flow patterns around the fins to try to understand the magnitude of the differences in the processes. The study is a first step in developing a new theory-based method to predict the performance of serrated fin tube bundles.

  12. The dynamic single-tube concept; Le mono-tube dynamique

    Energy Technology Data Exchange (ETDEWEB)

    Rivet, P. [Ste MC International (France)

    1997-12-31

    In the framework of greenhouse gas emission reduction and the utilization of cooling intermediate fluids with indirect refrigerating systems, a new concept of dynamical single-tube has been developed, which allows for the simultaneous cold distribution from a centralized plant towards various required temperature systems (as for example in a supermarket refrigerating system) with optimized efficiency, fluid flow and defrosting conditions; moreover, the dynamic single-tube concept is very well adapted to two-phase flows

  13. SG (steam generator) tube repair by explosive welding

    Energy Technology Data Exchange (ETDEWEB)

    Helmley, J.M. (Babcock and Wilcox Co., Lynchburg, VA (United States))

    1993-03-01

    Traditional joining techniques have limitations for bonding the ends of repair sleeves inside PWR cracked steam generator tubes. Explosive (kinetic) welding has been used as a successful alternative in over 5000 defective tubes. (author).

  14. An unusual conduit for a paediatric tracheostomy tube exchange

    African Journals Online (AJOL)

    The choice was guided by the internal diameter (ID) of the tracheostomy tube ... diameter of the TT (which is much larger than the external diameter (ED) of an endotracheal tube (ETT)). .... Age was a reliable predictor for tracheostomy size.

  15. 42 CFR 84.195 - Breathing tubes; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... Cartridge Respirators § 84.195 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with respirators shall be designed and constructed to prevent: (a) Restriction of free...

  16. 42 CFR 84.132 - Breathing tubes; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... Respirators § 84.132 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with supplied-air respirators shall be designed and constructed to prevent: (a) Restriction of free...

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

    Science.gov (United States)

    Studer, P.

    1965-01-01

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

  18. Disinfection of Biofilms in Tubes with Ultraviolet Light

    DEFF Research Database (Denmark)

    Bak, Jimmy; Begovic, Tanja

    2009-01-01

    Bacterial biofilms on long-term catheters are a major source of infection. We demonstrate here the potential of UVC light emitting diodes (LED) for disinfection purposes in catheter like tubes contaminated with biofilm. We show that UVC Light propagation is possible through teflon tubes using...... that the UVC light attenuation inside the tube can be described by an exponential function depending of tube length and various loss mechanisms. The disinfection efficiency of the UVC diodes is demonstrated on tubes contaminated artificially with a Pseudomonas aeruginosa biofilm. The tubes were connected...... the liquid light guiding principle. If the refractive index of the liquid is higher than that of the tube material light is guided inside the tube by internal reflections. To obtain a high refractive index of the liquid sodium chloride in high concentrations is added to the aqueous solution. It is shown...

  19. Development of a gradient tube method for examining microbial ...

    African Journals Online (AJOL)

    2013-06-24

    Jun 24, 2013 ... Development of a gradient tube method for examining microbial ... pathways, and possibly also in wastewater treatment operations, little is ... waters and describe here the development of a novel gradient tube method for ...

  20. The mechanism and key molecules involved in pollen tube guidance.

    Science.gov (United States)

    Higashiyama, Tetsuya; Takeuchi, Hidenori

    2015-01-01

    During sexual reproduction of flowering plants, pollen tube guidance by pistil tissue is critical for the delivery of nonmotile sperm cells to female gametes. Multistep controls of pollen tube guidance can be divided into two phases: preovular guidance and ovular guidance. During preovular guidance, various female molecules, including stimulants for pollen germination and pollen tube growth, are provided to support tube growth toward the ovary, where the ovules are located. After entering the ovary, pollen tubes receive directional cues from their respective target ovules, including attractant peptides for precise, species-preferential attraction. Successful pollen tube guidance in the pistil requires not only nutritional and directional controls but also competency controls to make pollen tubes responsive to guidance cues, regulation to terminate growth once a pollen tube arrives at the target, and strategies to stop ovular attraction depending on the fertilization of female gametes.

  1. Inertance Tube Modeling and the Effects of Temperature

    Science.gov (United States)

    2010-01-01

    compact and miniaturized high resolution capacitance dilatometer for measuring thermal expansion and magnetostriction Rev. Sci. Instrum. 83, 095102...acoustic power. KEYWORDS: Inertance tube, cryocoolers, pulse tube refrigerators, oscillating flow, computational fluid dynamics INTRODUCTION Pulse

  2. Split radius-form blocks for tube benders

    Science.gov (United States)

    Lange, D. R.; Seiple, C. W.

    1970-01-01

    Two-piece, radius-form block permits accurate forming and removing of parts with more than a 180 degree bend. Tube bender can shape flexible metal tubing in applications dealing with plumbing, heating, and pressure transmission lines.

  3. Stroke: ineffective tube securement reduces nutrition and drug treatment.

    Science.gov (United States)

    Brazier, Sophie; Taylor, Stephen J; Allan, Kaylee; Clemente, Rowan; Toher, Deirdre

    2017-06-22

    Stroke patients with dysphagia often depend on nutrition, hydration and medication via nasogastric (NG) feeding tubes. Securing tubes using tape is associated with repeated tube loss. In this study, the authors determined cause and effect by auditing tube placement methods, delays incurred, duration and costs. Of 202 NG tube placements in 75 patients, 67 placements occurred in 17 patients over a full course of enteral nutrition (EN) and 40 of these placements were tracked. Tubes were secured by tape in 100%, mittens 31% and special observation 5.4%. However, over an EN course, inadvertent tube loss occurred in 82% of patients and was associated with age (p=0.049) and mitten use (pnutrition, hydration and drug treatments; this may impair recovery. Reducing tube loss is likely to reduce patient distress, treatment cost and enhance recovery.

  4. Spontaneous resolution of pulmonary artery pseudoaneurysm after tube thoracostomy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Tong [Chunan Hospital, Soonchunhyang University, Chunan (Korea, Republic of)

    2005-07-15

    Pseudoaneurysm of the pulmonary artery is a rare complication occurring after tube thoracostomy. We report here on a case that displayed spontaneously resolution of a pulmonary artery pseudoaneurysm after tube thoracostomy.

  5. Gastrostomy tube feeding of children with cerebral palsy

    DEFF Research Database (Denmark)

    Dahlseng, Magnus O; Andersen, Guro L; DA Graca Andrada, Maria

    2012-01-01

    To compare the prevalence of gastrostomy tube feeding (GTF) of children with cerebral palsy (CP) in six European countries.......To compare the prevalence of gastrostomy tube feeding (GTF) of children with cerebral palsy (CP) in six European countries....

  6. How Do Health Care Providers Diagnose Neural Tube Defects?

    Science.gov (United States)

    ... and Publications How do health care providers diagnose neural tube defects? Skip sharing on social media links Share this: Page Content Neural tube defects are usually diagnosed before the infant is ...

  7. Are There Disorders or Conditions Associated with Neural Tube Defects?

    Science.gov (United States)

    ... Publications Are there disorders or conditions associated with neural tube defects? Skip sharing on social media links Share this: Page Content Infants born with neural tube defects that are not immediately fatal may have ...

  8. Risks of Ovarian, Fallopian Tube, and Primary Peritoneal Cancer Screening

    Science.gov (United States)

    ... Screening Research Ovarian, Fallopian Tube, and Primary Peritoneal Cancer Screening (PDQ®)–Patient Version What is screening? Go to ... ovarian cancer. Ovarian, Fallopian Tube, and Primary Peritoneal Cancer Screening Key Points Tests are used to screen for ...

  9. Ovarian, Fallopian Tube, and Primary Peritoneal Cancer Screening

    Science.gov (United States)

    ... Screening Research Ovarian, Fallopian Tube, and Primary Peritoneal Cancer Screening (PDQ®)–Patient Version What is screening? Go to ... ovarian cancer. Ovarian, Fallopian Tube, and Primary Peritoneal Cancer Screening Key Points Tests are used to screen for ...

  10. Glycol/water evacuated-tube solar collector

    Science.gov (United States)

    1980-01-01

    Report describes performance of 8 tube and 10 tube commercially produced solar collectors. Tests include thermal efficiency, time constant for temperature drop after solar flux is cut, change in efficiency with Sun angle, and temperature rise if circulation is stopped.

  11. Heat transfer during boiling at finned tubes and finned tube bundles; Der Waermeuebergang beim Sieden an Rippenrohren und Rippenrohrbuendeln

    Energy Technology Data Exchange (ETDEWEB)

    Chen Qiurong

    1991-06-10

    Based on bubble dynamics at single tubes and hydrodynamics at multi-tube arrangements (a vertical tube row, tube bundle), a theory for calculation of heat transfer at single tubes, at a vertical tube row and at tube bundles was developed. The theory applies both to finned tubes and plain tubes. To verify the presented theory, measured heat transfer coefficients taken from literature are recalculated. A comparison between heat transfer coefficients for single tubes and two-tube arrangements, calculated according to the theory and determined by measurements shows good agreement. Measuring results for plain tube bundles and bundles of finned tubes also agree well with the theory. (orig./MM) [Deutsch] Aufbauend auf der Blasendynamik an Einzelrohren und der Hydrodynamik in Mehrrohranordnungen (eine senkrechte Rohrreihe, Rohrbuendel) wurde eine Theorie zur Berechnung des Waermeuebergangs an Einzelrohren, an einer senkrechten Rohrreihe und an Rohrbuendeln entwickelt. Die Theorie gilt sowohl fuer Rippenrohre als auch fuer Glattrohre. Zur Ueberpruefung der vorgestellten Theorie werden gemessene Waermeuebergangskoeffizienten aus der Literatur nachgerechnet. Ein Vergleich zwischen den nach der Theorie berechneten und den aus Messungen ermittelten Waermeuebergangskoeffizienten fuer Einzelrohre und Zweirohranordnungen zeigt gute Uebereinstimmung. Auch die Messergebnisse von Glattrohrbuendeln und von Buendeln mit den Rippenrohren lassen sich durch die Theorie gut wiedergeben. (orig./MM)

  12. 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.

  13. Nonlinear seismic response analysis of reinforced concrete tube in tube structure

    Institute of Scientific and Technical Information of China (English)

    WANG Hai-bo; SHEN Pu-sheng

    2005-01-01

    Super-highly reinforced concrete tube in tube structure is a developing structure system of high-rise building. The more reasonable derivation process of the multi-vertical-line-element model stiffness matrix is given.On the premise of pointing out the problems of present multi-spring element model, combined with present multivertical-line-element model for analyzing on shear wall, the model is expanded to spatial one, and the stiffness matrix of which is derived. Combined with hysteretic axial model and hysteretic shear model, it is suitable for columns,wall limbs and beams with all kinds of section form. Some examples are calculated and compared with test results,which shows that the models have relatively good accuracy. On the base of the experimental phenomenon and failure mechanism for tube in tube structure specimen, nonlinear seismic responses analysis program on the basis of the advantaged element model for tube in tube structure is developed. Calculation results are in good agreement with those of the pseudo-dynamic tests and the failure mechanism can be well reflected.

  14. Film condensation of steam on externally finned horizontal tubes.

    OpenAIRE

    Flook, Frederick A.

    1985-01-01

    Approved for public release; distribution is unlimited Filmwise condensation measurements of steam were made on horizontal finned tubes under vacuum and near-atmospheric conditions. Data were obtained for copper tubes with fins of rectangular, triangular, trapezoidal, and parabolic cross sections, and for a commercially-available finned tube. A stainless steel finned tube was also tested to investigate the effect of thermal conductivity. Maximum enhancements of about 4.8 were obtained...

  15. Remote Pressure Control - Considering Pneumatic Tubes in Controller Design

    OpenAIRE

    Rager, David; Neumann, Rüdiger; Murrenhoff, Hubertus

    2016-01-01

    In pneumatic pressure control applications the influence of tubes that connect the valve with the control volume ist mainly neglected. This can lead to stability and robustness issues and limit either control performance or tube length. Modeling and considering tube behavior in controller design procedure allows longer tubes while maintaining the required performance and robustness properties without need for manual tuning. The author\\'s previously published Simplified Fluid Transmission Line...

  16. Yielding Torque-Tube System Reduces Crash Injuries

    Science.gov (United States)

    Mcsmith, D. G.

    1982-01-01

    Yielding torque-tube system minimizes injuries by limiting load transferred to occupant in crash. When properly integrated into seat structure, torque tube yields in plastic deformation stage of material and maintains a relatively constant resistance to applied torque for many degrees of rotation. Yielding torque-tube system is expected to find application in aircraft and automobile industries.

  17. 21 CFR 874.3930 - Tympanostomy tube with semipermeable membrane.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tympanostomy tube with semipermeable membrane. 874... Tympanostomy tube with semipermeable membrane. (a) Identification. A tympanostomy tube with a semipermeable membrane is a device intended to be implanted for ventilation or drainage of the middle ear and...

  18. 21 CFR 884.3650 - Fallopian tube prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Fallopian tube prosthesis. 884.3650 Section 884.3650 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... § 884.3650 Fallopian tube prosthesis. (a) Identification. A fallopian tube prosthesis is a...

  19. "Cool" Engagements with YouTube: Part 1

    Science.gov (United States)

    Trier, James

    2007-01-01

    This article discusses the participatory potential of YouTube, a social website that allows users to upload, view, and share video clips. The author provides examples of how YouTube was incorporated into a course as part of a "mosh-pit" pedagogy that involved both students and teachers in engaging with a variety of YouTube videos.

  20. Higher Education Migrates to YouTube and Social Networks

    Science.gov (United States)

    Gilroy, Marilyn

    2010-01-01

    True global enlightenment. That's how YouTubeEDU is being promoted by company officials who have announced the launch of a YouTube section devoted to academic content. Calling the new site "a free, self-organizing, democratic website containing all the world's knowledge," YouTubeEDU promises an environment in which "any qualified teacher can…

  1. YouTube, "Drug Videos" and Drugs Education

    Science.gov (United States)

    Manning, Paul

    2013-01-01

    Aims: This article reports on findings to emerge from a project examining YouTube "drug videos" in the light of an emerging literature on the relationship between YouTube and health education. The aim of this article is to describe the variety of discourses circulated by the "drug videos" available on YouTube and to consider the implications of…

  2. YouTube, "Drug Videos" and Drugs Education

    Science.gov (United States)

    Manning, Paul

    2013-01-01

    Aims: This article reports on findings to emerge from a project examining YouTube "drug videos" in the light of an emerging literature on the relationship between YouTube and health education. The aim of this article is to describe the variety of discourses circulated by the "drug videos" available on YouTube and to consider…

  3. Spallation of Small Particles From Peristaltic Pump Tube Segments.

    Science.gov (United States)

    Liu, Yi; Faria, Monica; Leonard, Edward

    2017-07-01

    In most extracorporeal filtration devices such as hemodialysis a peristaltic pump is used to circulate blood. Pump function requires the repeated compression of an elastomeric tube from which particles may be shed into the circulatory system, a process called spallation. Earlier studies are likely to have missed the large number of small particles (particles down to 0.6 µm. As polyvinyl chloride (PVC) tubing is commonly used for this process, a series of studies was conducted on three different types to study its spallation characteristics, along with a co-extruded PVC/polyurethane tubing known for its enhanced biocompatibility properties. For all types of PVC tubes, the average size of the spallated particles was 0.83 ± 0.03 µm; for the PVC/polyurethane tubing the average size of the spallated particles was approximately twice that reported for PVC tubing. For PVC tubes with equal inner diameter, those with less plasticizer released fewer particles; for tubes with the same Shore hardness, tubes with larger internal diameters released fewer particles. It was also shown that PVC tubes operating at a slower flow rate does not reduce the total number of particles released per volume pumped. The total number of particles spallated from the PVC/polyurethane tubing was 10 times lower than from the lowest spallating PVC tubing. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  4. The Topology of Canonical Flux Tubes in Flared Jet Geometry

    Science.gov (United States)

    Sander Lavine, Eric; You, Setthivoine

    2017-01-01

    Magnetized plasma jets are generally modeled as magnetic flux tubes filled with flowing plasma governed by magnetohydrodynamics (MHD). We outline here a more fundamental approach based on flux tubes of canonical vorticity, where canonical vorticity is defined as the circulation of the species’ canonical momentum. This approach extends the concept of magnetic flux tube evolution to include the effects of finite particle momentum and enables visualization of the topology of plasma jets in regimes beyond MHD. A flared, current-carrying magnetic flux tube in an ion-electron plasma with finite ion momentum is thus equivalent to either a pair of electron and ion flow flux tubes, a pair of electron and ion canonical momentum flux tubes, or a pair of electron and ion canonical vorticity flux tubes. We examine the morphology of all these flux tubes for increasing electrical currents, different radial current profiles, different electron Mach numbers, and a fixed, flared, axisymmetric magnetic geometry. Calculations of gauge-invariant relative canonical helicities track the evolution of magnetic, cross, and kinetic helicities in the system, and show that ion flow fields can unwind to compensate for an increasing magnetic twist. The results demonstrate that including a species’ finite momentum can result in a very long collimated canonical vorticity flux tube even if the magnetic flux tube is flared. With finite momentum, particle density gradients must be normal to canonical vorticities, not to magnetic fields, so observations of collimated astrophysical jets could be images of canonical vorticity flux tubes instead of magnetic flux tubes.

  5. 42 CFR 84.115 - Breathing tubes; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing tubes; minimum requirements. 84.115 Section 84.115 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL... § 84.115 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with...

  6. 42 CFR 84.72 - Breathing tubes; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing tubes; minimum requirements. 84.72...-Contained Breathing Apparatus § 84.72 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with breathing apparatus shall be designed and constructed to prevent: (a)...

  7. 42 CFR 84.172 - Breathing tubes; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing tubes; minimum requirements. 84.172... Air-Purifying Particulate Respirators § 84.172 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with respirators shall be designed and constructed to prevent:...

  8. On the generation of flux tube waves in stellar convection zones. I - Longitudinal tube waves driven by external turbulence

    Science.gov (United States)

    Musielak, Z. E.; Rosner, R.; Ulmschneider, P.

    1989-01-01

    The source functions and the energy fluxes for wave generation in magnetic flux tubes embedded in an otherwise magnetic field-free, turbulent, and compressible fluid are derived. The calculations presented here assume that the tube interior is not itself turbulent, e.g., that motions within the flux tube are due simply to external excitation. Specific results for the generation of longitudinal tube waves are presented.

  9. Small-bore chest tubes seem to perform better than larger tubes in treatment of spontaneous pneumothorax

    DEFF Research Database (Denmark)

    Iepsen, Ulrik Winning; Ringbæk, Thomas

    2013-01-01

    The aim of this study was to compare the efficacy and complications of surgical (large-bore) chest tube drainage with smaller and less invasive chest tubes in the treatment of non-traumatic pneumothorax (PT). ......The aim of this study was to compare the efficacy and complications of surgical (large-bore) chest tube drainage with smaller and less invasive chest tubes in the treatment of non-traumatic pneumothorax (PT). ...

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

    Energy Technology Data Exchange (ETDEWEB)

    Bucholz, J.A.

    2000-07-01

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

  11. Effect of tube pitch on heat transfer in shell-and-tube heat exchangers—new simulation software

    Science.gov (United States)

    Karno, A.; Ajib, S.

    2006-02-01

    A new program for simulation and optimization of the shell-and-tube heat exchangers is prepared to obtain useful results by employment of the computing technology fast and accurately. As an application of this program, the effects of transverse and longitudinal tube pitch in the in-line and staggered tube arrangements on the Nusselt numbers, heat transfer coefficients and thermal performance of the heat exchangers were investigated. The obtained values of the tube pitch were compared with literature values.

  12. Retractable tube design issues in ITER CXRS UPP no. 3

    Energy Technology Data Exchange (ETDEWEB)

    Baross, T., E-mail: baross.teteny@wigner.mta.hu [WIGNER RCP, RMKI, PO Box 91, H-1521 Budapest (Hungary); Biel, W. [Institut für Energieforschung – Plasmaphysik, Forschungszentrum Jülich Gmbh, Association EURATOM-FZJ, Member of Trilateral Euregio Cluster, 52425 Jülich (Germany); Krejczinger, A. [WIGNER RCP, RMKI, PO Box 91, H-1521 Budapest (Hungary); Krasikov, Yu.; Panin, A. [Institut für Energieforschung – Plasmaphysik, Forschungszentrum Jülich Gmbh, Association EURATOM-FZJ, Member of Trilateral Euregio Cluster, 52425 Jülich (Germany)

    2013-10-15

    Highlights: ► The retractable tube is located in the upper port plug no. 3 of ITER core charge exchange recombination spectroscopy (cCXRS) that carries the cleaning system of the first mirror. ► Various manufacturing methods were investigated for the proper layout of the tube cooling structure. ► The tube support boundary conditions were examined. ► A flexible compensator element was developed between the floating and structural flange of the tube. -- Abstract: The retractable tube is located in the upper port plug no. 3 of ITER core charge exchange recombination spectroscopy (cCXRS), where it is surrounded by a set of mirrors, diagnostic shielding module (DSM), outer shell, cleaning device and shutter. Accordingly to the recent port plug concept the tube is an optional unit that carries the cleaning system of the first mirror. The cleaning device shall be a compact instrument at the tube head that influences the tube diameter primarily. Independently of the cleaning device the tube cooling channels and its proper support concept has to be developed. Various manufacturing methods are investigated for the proper layout of the tube cooling structure. They are the gun-drilled deep holes, the solid state bonded sheets forming cooling channels between the welded layers, ‘tube-in-tube’ approach. Most of them were analyzed in view of their thermal conditions. The tube support system design is a complex task, that has to take into account several boundary conditions and limitations. The tube must be compatible with the assumed ITER generic installation procedure, withstand the electromagnetic (EM) and thermal loads. Furthermore, the tube has to be exchanged several times during its lifetime. The paper summarizes the tube cooling layout possibilities and the assumptions on its support concepts.

  13. Miura Tubes and Assemblages: Theory and Applications

    Science.gov (United States)

    Filipov, Evgueni; Paulino, Glaucio; Tachi, Tomohiro

    2015-03-01

    Origami systems inspired from the Miura-ori pattern are rigid and flat foldable meaning that they can fold completely by deforming only about prescribed fold lines. We investigate origami tubes and assemblages constructed from Miura-ori inspired sheets and use eigenvalue analyses to study their stiffness characteristics. A simplified bar model is used to model the stretching and shear of the flat panel segments and rotational hinges are used to simulate the bending stiffness of the panels and prescribed fold lines. We discuss the small to large deformation bending of thin sheets and show an improved method to estimate stiffness when modeling origami structures. The tube assemblages show interesting behaviors that make them suitable for applications in science and engineering.

  14. Premixed flame propagation in vertical tubes

    CERN Document Server

    Kazakov, Kirill A

    2015-01-01

    Analytical treatment of premixed flame propagation in vertical tubes with smooth walls is given. Using the on-shell flame description, equations describing quasi-steady flame with a small but finite front thickness are obtained and solved numerically. It is found that near the limits of inflammability, solutions describing upward flame propagation come in pairs having close propagation speeds, and that the effect of gravity is to reverse the burnt gas velocity profile generated by the flame. On the basis of these results, a theory of partial flame propagation driven by the gravitational field is developed. A complete explanation is given of the intricate observed behavior of limit flames, including dependence of the inflammability range on the size of the combustion domain, the large distances of partial flame propagation, and the progression of flame extinction. The role of the finite front-thickness effects is discussed in detail. Also, various mechanisms governing flame acceleration in smooth tubes are ide...

  15. Tympanostomy tubes: patient selection and special considerations

    Directory of Open Access Journals (Sweden)

    Whittemore Jr KR

    2015-05-01

    Full Text Available Kenneth R Whittemore Jr Department of Otolaryngology and Communication Enhancement, Boston Children's Hospital, Boston, MA, USA Abstract: Indications for tympanostomy tube (TT placement in children with chronic serous effusions and hearing loss are fairly well established. The use of TTs for children with recurrent acute otitis media (rAOM has not been studied as extensively as for those with hearing loss from middle-ear effusions. There is a subset of children who fall outside established guidelines for either of the preceding categories who may benefit from TT placement. The indications for TT placement in children with middle-ear disease are discussed. Keywords: tympanostomy tubes, pediatrics, otitis media with effusion, acute otitis media, hearing loss

  16. FAILURES AND THE LIFE OF FURNACE TUBES

    Institute of Scientific and Technical Information of China (English)

    F.Z.Shen; Y.Ding; D.M.Hou; Z.P.Ning; Y.Lü; T.B.Dong; A.R.Tuohuti

    2004-01-01

    It is showed after the furnace tubes serviced for 8-10 years that the density of damage in the HAZ (heat affected zone) of the weld has higher than in parent metals, though the depth of damage is not equal to. By the test of creep crack growth, it is also acquired that under same mechanic parameter C* (t), the rate of creep crack growth in the HAZ is more than twice as fast as in parent metals. Two mechanisms (overheating and thermal shock) of failure occurred in an accident are presented. The stress of thermal shock is analyzed, in which the change of the elasticity modulus with the radius ET = f(r) is considered. Based on it, the safety region of the thermal shock is obtained. Finally, two sets of curves for the safe life are suggested which can facilitate to estimate the remaining life of HK-40 or HP-Nb tubes by their creep rupture data.

  17. Raytheon advanced pulse-tube cryocoolers

    Science.gov (United States)

    Conrad, Ted; Yates, Ryan; Kuo, Daniel; Schaefer, Brian; Arnoult, Matt

    2016-05-01

    Since the 1970s, Raytheon has developed, built, tested and integrated high performance cryocoolers. Our versatile designs for single and multi-stage cryocoolers provide reliable operation for temperatures from 10 to 200 Kelvin with power levels ranging from 50 W to nearly 600 W. These cryocoolers incorporate clearance seals, flexure suspensions, hermetic housings and dynamic balancing to provide long service life and reliable operation in all relevant environments. Recently, Raytheon has developed an advanced regenerator technology capable of operating efficiently at high frequencies and outperforming traditional screen regenerators. The Raytheon Advanced Miniature (RAM-100) cryocooler, a flight packaged, high frequency, single stage pulse tube cooler with an integrated surge volume and inertance tube, has been designed for use with this regenerator. Design details and experimentally measured performance of two iterations of the RAM cryocooler are presented in this paper.

  18. 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.

  19. Pentaquark in the flux tube model

    Science.gov (United States)

    Iwasaki, M.; Takagi, F.

    2008-03-01

    We propose a model for pentaquarks in an excited state in the flux tube picture. The pentaquark is assumed to be composed of two diquarks and an antiquark connected by a color flux tube with a junction. If the pentaquark is rotating rapidly, it is polarized into two clusters: one is a diquark and the other is an antiquark plus another diquark. Excited energy of this quasilinear system is calculated with the use of the WKB approximation. It is predicted that there exist quasistable excited pentaquarks: 1690MeV(3/2+), 2000MeV(5/2-), 2250MeV(7/2+) etc., which decay mainly through three-body modes.

  20. Broken tracheostomy tube: A fractured mandate

    Directory of Open Access Journals (Sweden)

    Arvind Krishnamurthy

    2012-01-01

    Full Text Available Tracheostomy is a common airway procedure for life support. This procedure is safe, although occasional early and late complications are known to occur. Fracture and hence aspiration of a tracheostomy tube in the tracheobronchial tree is a rare late complication, which can be potentially life threatening. Published reports of a fractured tracheostomy tube presenting as a foreign body in the tracheobronchial tree are few. The most common dislodged sites reported were the trachea and the right main bronchus, the inner flange in our patient was lodged in the trachea and the left main bronchus. Foreign-body aspiration is a serious medical emergency demanding timely recognition and prompt action as was successfully done in our patient. Therapeutic rigid bronchoscopic removal is the mainstay of treatment. A periodic review of the techniques of tracheostomy care including timely check-ups for signs of wear and tear can possibly eliminate such avoidable late complications.

  1. Clean Industrial Room for Drift Tube Assembling

    CERN Document Server

    Glonti, GL; Evtoukhovitch, P G; Kroa, G; Manz, A; Potrap, I N; Rihter, P; Stoletov, G D; Tskhadadze, E G; Chepurnov, V F; Chirkov, A V; Shelkov, G A

    2001-01-01

    Description of a clean industrial room for assembly of drift tubes for the muon spectrometer of the ATLAS experiment is presented. High quality specifications on the detectors to be produced demanded creation of a workplace with stable temperature and humidity, as well as minimum quantity of dust in the room. Checking of parameters of intra-room air during long period of continuous work has been confirmed correctness of the designed characteristics of the climatic system installed in the clean room. The room large volum (\\sim 190 m^3), the powerful and flexible climatic system, and simplicity of service allow assembling of detectors with length up to 5 m. Subsequent checking of functionality of the assembled detectors has shown high quality of assembling (the amount of rejected tubes does not exceed 2 %). It demonstrates conformity to the assembling quality requirements for mass production of drift chambers for the muon spectrometer.

  2. 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.

  3. YouTube Extension of Music Memory

    Directory of Open Access Journals (Sweden)

    Trena Jordanoska

    2014-12-01

    Full Text Available Individual work approach to collective cultural memory is marked by unprecedented digital tool – Internet. Social networks accelerated the exchange of music artifacts to extremely large numbers of participants. One of the important aspects of the new digital transition is that the improved transfer rates resulted in an audio quality approaching the limits of human hearing. YouTube counter is undoubtedly the best indicator for the presence of these artifacts in virtual reality. The records of the downloads of the “Gangnam Style” song in billion, support the argument for the influence of the new technological means on collective memory. In our research we collected and analyzed the data regarding music posting on YouTube.

  4. Useful scaling parameters for the pulse tube

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.M.; Kittel, P. [NASA Ames Research Center, Moffett Field, CA (United States); Timmerhaus, K.D. [Univ. of Colorado, Boulder, CO (United States)] [and others

    1996-12-31

    A set of dimensionless scaling parameters for use in correlating performance data for Pulse Tube Refrigerators is presented. The dimensionless groups result after scaling the mass and energy conservation equations, and the equation of motion for an axisymmetric, two-dimensional ideal gas system. Allowed are viscous effects and conduction heat transfer between the gas and the tube wall. The scaling procedure results in reducing the original 23 dimensional variables to a set of 11 dimensionless scaling groups. Dimensional analysis is used to verify that the 11 dimensionless groups obtained is the minimum number needed to describe the system. The authors also examine 6 limiting cases which progressively reduce the number of dimensionless groups from 11 to 3. The physical interpretation of the parameters are described, and their usefulness is outlined for understanding how heat transfer and mass streaming affect ideal enthalpy flow.

  5. Flexible tube lattice fibers for terahertz applications.

    Science.gov (United States)

    Setti, V; Vincetti, L; Argyros, A

    2013-02-11

    In this paper a flexible hollow core waveguide for the terahertz spectral range is demonstrated. Its cladding is composed of a circular arrangement of dielectric tubes surrounded by a heat-shrink jacket that allows the fiber to be flexible. Characterization of straight samples shows that the hollow core allows the absorption caused by the polymethylmethacrylate tubes of the cladding to be reduced by 31 times at 0.375 THz and 272 times at 0.828 THz with respect to the bulk material, achieving losses of 0.3 and 0.16 dB/cm respectively. Bending loss is also experimentally measured and compared to numerical results. For large bending radii bending loss scales as Rb-2, whereas for small bending radii additional resonances between core and cladding appear. The transmission window bandwidth is also shown to shrink as the bending radius is reduced. An analytical model is proposed to predict and quantify both of these bending effects.

  6. Shock Tube as an Impulsive Application Device

    Directory of Open Access Journals (Sweden)

    Soumya Ranjan Nanda

    2017-01-01

    Full Text Available Current investigations solely focus on application of an impulse facility in diverse area of high-speed aerodynamics and structural mechanics. Shock tube, the fundamental impulse facility, is specially designed and calibrated for present objectives. Force measurement experiments are performed on a hemispherical test model integrated with the stress wave force balance. Similar test model is considered for heat transfer measurements using coaxial thermocouple. Force and heat transfer experiments demonstrated that the strain gauge and thermocouple have lag time of 11.5 and 9 microseconds, respectively. Response time of these sensors in measuring the peak load is also measured successfully using shock tube facility. As an outcome, these sensors are found to be suitable for impulse testing. Lastly, the response of aluminum plates subjected to impulsive loading is analyzed by measuring the in-plane strain produced during deformation. Thus, possibility of forming tests in shock is also confirmed.

  7. I Tune, You Tube, We Rule

    Science.gov (United States)

    Shida, R. Y.; Gater, W.

    2007-10-01

    The website YouTube was created in 2005 and has rapidly become one of the most popular entertainment websites on the internet. It is riding the online video wave today like few other online companies and is currently more popular than the video sections of either Yahoo or Google. iTunes, a digital media application created by Apple in 2001, where one can download and play music and videos, has had a similar success. There is little doubt that they both represent important communication channels in a world heavily influenced by online media, especially among teenagers and young adults. As science communicators we can use this direct route to a younger audience to our advantage. This article aims to give a taste of these applications with a few selected examples demonstrating that both YouTube and iTunes are excellent tools to teach and inspire the general public.

  8. 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)

  9. The evaluation of the angles of Eustachian tubes in the patients with ...

    African Journals Online (AJOL)

    2015-12-02

    Dec 2, 2015 ... Relationship between COM with the eustachian tube anatomical and ... tube show us that the differences of the physiology of eustachian tube due to ..... Descriptive anatomy of the human auditory tube. Surg Radiol Anat. 1998 ...

  10. Superheater Tube Flat Wall Stationary Temperature Field

    Directory of Open Access Journals (Sweden)

    Parpiev A.T.

    2016-01-01

    Full Text Available The BKZ-220-100-9 steam generator platen superheater tube flat wall stationary temperature fields analysis have been made. The six steel grades, using in boiler fabrication, namely, St. 10, St. 20, 12H1MF, 15HM, 1H18N9T and 12H18N12T, have been used. The temperature curves calculation has been made by using outer and inner surface heat-transfer coefficients nine different combinations.

  11. Radioactive fallout and neural tube defects

    Directory of Open Access Journals (Sweden)

    Nejat Akar

    2015-10-01

    Full Text Available Possible link between radioactivity and the occurrence of neural tube defects is a long lasting debate since the Chernobyl nuclear fallout in 1986. A recent report on the incidence of neural defects in the west coast of USA, following Fukushima disaster, brought another evidence for effect of radioactive fallout on the occurrence of NTD’s. Here a literature review was performed focusing on this special subject.

  12. Shock tubes and blast injury modeling

    Institute of Scientific and Technical Information of China (English)

    Ya-Lei Ning; Yuan-Guo Zhou

    2015-01-01

    Explosive blast injury has become the most prevalent injury in recent military conflicts and terrorist attacks.The magnitude of this kind of polytrauma is complex due to the basic physics of blast and the surrounding environments.Therefore,development of stable,reproducible and controllable animal model using an ideal blast simulation device is the key of blast injury research.The present review addresses the modeling of blast injury and applications of shock tubes.

  13. Removal of External Deposits on Boiler Tubes

    Directory of Open Access Journals (Sweden)

    C. P. De

    1970-07-01

    Full Text Available The superheater tubes in Port and Starboard boilers were found to have completely clogged by heavy deposits, which on analysis mainly vanadium pentoxide and sodium sulphmatter. The cleaning of the deposits was accomplished by alternate spraying with 15-20 per cent hydrogen peroxide and washing with hot water jets. Over the past two years, since the date of cleaning, the IN ship is operating without any trouble in the boilers.

  14. Heat Transfer Analysis of Fin Tube

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Woo-Jin [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Choi, Cheng-Ryul [ELSOLTEC Co., Yongin (Korea, Republic of)

    2015-10-15

    This paper describes a preliminary numerical analysis of fin tube used for a heat exchanger of the air-water cooling system. The internal flow in a fin tube is steam and the external of the fin is cooled by air. Cooling system in a nuclear power plant can be divided into two categories; 1) active pump driven system powered by alternating current and 2) passive cooling system drived by natural circulation phenomena. After the accident in Hukushima Nuclear Power Plants, the importance of the passive cooling system that can provide a long-term cooling of reactor decay heat during station blackout condition is emphasized. However, the effectiveness of passive cooling system based on cooling water is limited by the capacity of water storage tank. To overcome the limit due to the exhaustion of the cooling water, an natural convection air cooling system is proposed. As the air operated cooling system utilizes natural circulation phenomena of air, it does not require cooling water. However, the heat transfer area of the air operated cooling system should be increased much as the heat removal capacity per unit area is much lower than that of water cooling system. The air-water combined cooling system can resolve this excess increase of the heat transfer area in the air operated cooling system. This air-water cooling system can be also used in the passive containment cooling system. The effect of design parameters such as fin tube arrangement, the fin height, and pitch has been analyzed and the chimney effect on the simulation of heat transfer in a heat exchanger is evaluated. The internal flows in a fin tube heat exchanger for natural circulation flow condition and forced convection (suction) condition were investigated.

  15. Sizing-tube-fin space radiators

    Science.gov (United States)

    Peoples, J. A.

    1978-01-01

    Temperature and size considerations of the tube fin space radiator were characterized by charts and equations. An approach of accurately assessing rejection capability commensurate with a phase A/B level output is reviewed. A computer program, based on Mackey's equations, is also presented which sizes the rejection area for a given thermal load. The program also handles the flow and thermal considerations of the film coefficient.

  16. Performance of an adjustable, threaded inertance tube

    Science.gov (United States)

    Zhou, W. J.; Pfotenhauer, J. M.; Nellis, G. F.; Liu, S. Y.

    2015-12-01

    The performance of the Stirling type pulse tube cryocooler depends strongly on the design of the inertance tube. The phase angle produced by the inertance tube is very sensitive to its diameter and length. Recent developments are reported here regarding an adjustable inertance device that can be adjusted in real time. The inertance passage is formed by the root of a concentric cylindrical threaded device. The depth of the threads installed on the outer screw varies. In this device, the outer screw can be rotated four and half turns. At the zero turn position the length of the passage is 1.74 m and the hydraulic diameter is 7 mm. By rotating the outer screw, the inner threaded rod engages with additional, larger depth threads. Therefore, at its upper limit of rotation, the inertance passage includes both the original 1.74 m length with 7mm hydraulic diameter plus an additional 1.86 m length with a 10 mm hydraulic diameter. A phase shift change of 24° has been experimentally measured by changing the position of outer screw while operating the device at a frequency of 60 Hz. This phase angle shift is less than the theoretically predicted value due to the presence of a relatively large leak through the thread clearance. Therefore, the distributed component model of the inertance tube was modified to account for the leak path causing the data to agree with the model. Further, the application of vacuum grease to the threads causes the performance of the device to improve substantially.

  17. YouTube and Video Quizzes

    Science.gov (United States)

    Yee, Kevin; Hargis, Jace

    2010-01-01

    The Internet sensation YouTube (http://www.youtube.com) has become such a force online that it was estimated in 2006 to account for a full tenth of the bandwidth by the entire Internet in the United States (WebProNews, 2007), and to use as much bandwidth in 2007 as the entire Internet had done in 2000 (Carter, 2008). Like many technological tools…

  18. Explosively Bonded Gun Tube Liner Development

    Science.gov (United States)

    2015-04-01

    level (MRL 10) measures aspects of lean practices and continuous improvement for systems in production. C.1 MRL 1: Basic Manufacturing Implications...the art is assessed through the use of Technology and Manufacturing Readiness Levels. 15. SUBJECT TERMS Ta alloys, gun-tube liners, explosive...bonding, firing tests, Technology Readiness Level, Manufacturing Readiness Level 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UU 18

  19. Models of Flux Tubes from Constrained Relaxation

    Indian Academy of Sciences (India)

    Α. Mangalam; V. Krishan

    2000-09-01

    We study the relaxation of a compressible plasma to an equilibrium with flow. The constraints of conservation of mass, energy, angular momentum, cross-helicity and relative magnetic helicity are imposed. Equilibria corresponding to the energy extrema while conserving these invariants for parallel flows yield three classes of solutions and one of them with an increasing radial density profile, relevant to solar flux tubes is presented.

  20. YouTube pranking across cultures

    OpenAIRE

    2015-01-01

    Online pranking videos are common online and popular among middle-school students, teens and young adults. When we examined 200 YouTube examples of the Scary Maze Game prank, we explored the relationship between perpetrator, victim and witness, finding that while American children under age 12 were commonly featured as victims in Scary Maze Game prank videos, only rarely were German children represented as victims. U.S. videos also lingered on the pain of prank victims, even looping the emoti...

  1. Emergency battlefield cricothyrotomy complicated by tube occlusion

    Science.gov (United States)

    Gallo, Andrew C; Adams, Bruce D

    2009-01-01

    Emergency cricothyrotomy is a technique used to secure an otherwise compromised or inaccessible airway and has been recommended for use in the battlefield under certain circumstances. This case reports an acute complication of emergency cricothyrotomy. An Iraqi soldier, injured in an improvised explosive device blast received an emergency battlefield cricothyrotomy. At the Combat Support Hospital, the patient became more difficult to ventilate and was taken to the operating room for tracheostomy. The cricothyrotomy tube was found to be occluded with blood. PMID:19561959

  2. YouTube Extension of Music Memory

    OpenAIRE

    Trena Jordanoska

    2014-01-01

    Individual work approach to collective cultural memory is marked by unprecedented digital tool – Internet. Social networks accelerated the exchange of music artifacts to extremely large numbers of participants. One of the important aspects of the new digital transition is that the improved transfer rates resulted in an audio quality approaching the limits of human hearing. YouTube counter is undoubtedly the best indicator for the presence of these artifacts in virtual reality. The records of ...

  3. PHASE CHANGE AROUND A FINNED TUBE

    OpenAIRE

    EREK, Aytunç

    2003-01-01

    This study presents the heat transfer enhancement in the thermal energy storage system by using radially finned tube. The solution of the system consists of the solving the equations of the heat transfer fluid (HTF), the pipe wall and fin, and the phase change material (PCM) as one domain. The control volume finite difference approach and the semi implicit solver (SIS) are used to solve the equations. Fully developed velocity distribution is taken in the HTF. Flow parameters (Re number and in...

  4. Hydrostatic Extrusion of 60mm Mortar Tubes

    Science.gov (United States)

    1974-10-01

    REPORT NUMBeRf 7. AUT.Oft(s) S. CONTRACrOft GRANT MUMSER(s) Richard S. DeFries 2. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PRPOGRA~m KIEMEr...8 hrs.) and sse~uently I0 Zte ftelle to costetc their preesing . 3 B3. Visual and Dimensional Check of Tubes The Inconel 718 alloy as-extruded and aged

  5. Dynamics of miscible displacements in round tubes

    Energy Technology Data Exchange (ETDEWEB)

    Meiburg, E.; Maxworthy, T.; Chen, C.Y. [Univ. of Southern California, Los Angeles, CA (United States); Petitjeans, P. [Ecole Superieure de Physique et de Chimie Industrielles, Paris (France)

    1995-12-31

    A combined experimental and numerical investigation of miscible two-phase flow in a capillary tube is reported. The fraction of fluid left behind on the wall is obtained as a function of the Peclet, Atwood, and Froude numbers. Scaling arguments are presented for two distinct flow regimes, dominated by diffusion and convection, respectively. In the latter one, an effective surface tension value can be estimated.

  6. Tension Pneumothorax and Subcutaneous Emphysema Complicating Insertion of Nasogastric Tube

    Directory of Open Access Journals (Sweden)

    Narjis AL Saif

    2015-01-01

    Full Text Available Nasogastric tube has a key role in the management of substantial number of hospitalized patients particularly the critically ill. In spite of the apparent simple insertion technique, nasogastric tube placement has its serious perhaps fatal complications which need to be carefully assessed. Pulmonary misplacement and associated complications are commonplace during nasogastric tube procedure. We present a case of tension pneumothorax and massive surgical emphysema in critically ill ventilated patient due to inadvertent nasogastric tube insertion and also discussed the risk factors, complication list, and arrays of techniques for safer tube placement.

  7. Study on Thermo-Conductive Plastic Finned Tube Radiators

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    This paper discusses thermo-conductive plastic finned tube radiators used in water saving type power stations.First,the development of thermo-conductive plastics is introduced.Second,in order to determine the rational geometric dimensions of thermo-conductive plastic finned tubes,an objective function which takes the minimum volume of the consumed material for making finned tubes as an object is introduced.On the basis of the function,the economy comparison between thermo-conductive plastic finned tubes and metal finned tubes is conducted.

  8. Some aspects of film condensation of steam on finned tubes

    OpenAIRE

    Coumes, James M.

    1989-01-01

    Approved for public release; distribution is unlimited Heat-transfer measurements were made for filmwise condensation of steam on smooth tubes and finned tubes with rectangular-shaped fins. The influence of fin root diameter on a single horizontal finned tube was examined by taking data for two families of tubes whose fin root diameters were 12.7 and 19.05 mm. Each family of tubes had fins that were 1 mm thick and 1 mm high but with fin spacings of 0.25, 0.50, 1.0, 1.5, 2.0, and 4.0 mm. ...

  9. Intraoperative wide bore nasogastric tube knotting: A rare incidence.

    Science.gov (United States)

    Lamba, Sangeeta; Sethi, Surendra K; Khare, Arvind; Saini, Sudheendra

    2016-01-01

    Nasogastric tubes are commonly used in anesthetic practice for gastric decompression in surgical patients intraoperatively. The indications for its use are associated with a number of potential complications. Knotting of small-bore nasogastric tubes is usually common both during insertion and removal as compared to wide bore nasogastric tubes. Knotting of wide bore nasogastric tube is a rare complication and if occurs usually seen in long standing cases. We hereby report a case of incidental knotting of wide bore nasogastric tube that occurred intraoperatively.

  10. Tension Pneumothorax and Subcutaneous Emphysema Complicating Insertion of Nasogastric Tube.

    Science.gov (United States)

    Al Saif, Narjis; Hammodi, Adel; Al-Azem, M Ali; Al-Hubail, Rasheed

    2015-01-01

    Nasogastric tube has a key role in the management of substantial number of hospitalized patients particularly the critically ill. In spite of the apparent simple insertion technique, nasogastric tube placement has its serious perhaps fatal complications which need to be carefully assessed. Pulmonary misplacement and associated complications are commonplace during nasogastric tube procedure. We present a case of tension pneumothorax and massive surgical emphysema in critically ill ventilated patient due to inadvertent nasogastric tube insertion and also discussed the risk factors, complication list, and arrays of techniques for safer tube placement.

  11. Esophageal rupture due to Sengstaken-Blakemore tube misplacement

    Institute of Scientific and Technical Information of China (English)

    Chee-Fah Chong

    2005-01-01

    The author presents three cases of esophageal rupture during the treatment of massive esophageal variceal bleeding with Sengstaken-Blakemore (SB) tube. In each case, simple auscultation was used to guide SB tube insertion, with chest radiograph obtained only after complete inflation of the gastric balloon. Two patients died of hemorrhagic shock and one died of mediastinitis.The author suggests that confirmation of SB tube placement by auscultation alone may not be adequate.Routine chest radiographs should be obtained before and after full inflation of the gastric balloon to confirm tube position and to detect tube dislocation.

  12. Optimization of the Single Staggered Wire and Tube Heat Exchanger

    OpenAIRE

    Arsana I Made; Susianto; Budhikarjono Kusno; Altway Ali

    2016-01-01

    Wire and tube heat exchanger consists of a coiled tube, and wire is welded on the two sides of it in normal direction of the tube. Generally,wire and tube heat exchanger uses inline wire arrangement between the two sides, whereas in this study, it used staggered wire arrangement that reduces the restriction of convection heat transfer. This study performed the optimization of single staggered wire and tube heat exchanger to increase the capacity and reduce the mass of the heat exchanger. Opti...

  13. Stable sonoluminescence within a water hammer tube.

    Science.gov (United States)

    Chakravarty, Avik; Georghiou, Theo; Phillipson, Tacye E; Walton, Alan J

    2004-06-01

    The sonoluminescence (SL) from the collapse of a single gas bubble within a liquid can be produced repetitively using an acoustic resonator. An alternative technique using a water hammer tube, producing SL from bubbles of greater size, is described here. A sealed vertical tube partly filled with a liquid and a gas at low pressure is subjected to vertical vibrations. The oscillation of the pressure within the liquid column, due to inertial forces, excites cavitation bubbles to grow and collapse. Rotation is used to confine the bubbles to the axis of the tube. Bright SL emissions were observed in a number of liquids. Repetitive emission was produced from bubbles in condensed phosphoric acid. Bubbles of 0.4 mm ambient radius (containing 2x 10(14) xenon atoms) were excited by vibration at 35 Hz. Approximately 10(12) photons were emitted per collapse in the range 400-700 nm (over four orders of magnitude greater than the brightest SL reported previously), corresponding to a 1% efficiency of the conversion of mechanical energy into light.

  14. Neural Tube Defects, Folic Acid and Methylation

    Directory of Open Access Journals (Sweden)

    Henk J. Blom

    2013-09-01

    Full Text Available Neural tube defects (NTDs are common complex congenital malformations resulting from failure of the neural tube closure during embryogenesis. It is established that folic acid supplementation decreases the prevalence of NTDs, which has led to national public health policies regarding folic acid. To date, animal studies have not provided sufficient information to establish the metabolic and/or genomic mechanism(s underlying human folic acid responsiveness in NTDs. However, several lines of evidence suggest that not only folates but also choline, B12 and methylation metabolisms are involved in NTDs. Decreased B12 vitamin and increased total choline or homocysteine in maternal blood have been shown to be associated with increased NTDs risk. Several polymorphisms of genes involved in these pathways have also been implicated in risk of development of NTDs. This raises the question whether supplementation with B12 vitamin, betaine or other methylation donors in addition to folic acid periconceptional supplementation will further reduce NTD risk. The objective of this article is to review the role of methylation metabolism in the onset of neural tube defects.

  15. MAGNETIC FLUX TUBE INTERCHANGE AT THE HELIOPAUSE

    Energy Technology Data Exchange (ETDEWEB)

    Florinski, V., E-mail: vaf0001@uah.edu [Department of Space Science and Center for Space Plasma and Aeronomic Research, University of Alabama in Huntsville, Huntsville, AL 35899 (United States)

    2015-11-01

    The magnetic field measured by Voyager 1 prior to its heliocliff encounter on 2012.65 showed an unexpectedly complex transition from the primarily azimuthal inner-heliosheath field to the draped interstellar field tilted by some 20° to the nominal azimuthal direction. Most prominent were two regions of enhanced magnetic field strength depleted in energetic charged particles of heliospheric origin. These regions were interpreted as magnetic flux tubes connected to the outer heliosheath that provided a path for the particles to escape. Despite large increases in strength, the field’s direction did not change appreciably at the boundaries of these flux tubes. Rather, the field’s direction changed gradually over several months prior to the heliocliff crossing. It is shown theoretically that the heliopause, as a pressure equilibrium layer, can become unstable to interchange of magnetic fields between the inner and the outer heliosheaths. The curvature of magnetic field lines and the anti-sunward gradient in plasma kinetic pressure provide conditions favorable for an interchange. Magnetic shear between the heliosheath and the interstellar fields reduces the growth rates, but does not fully stabilize the heliopause against perturbations propagating in the latitudinal direction. The instability could create a transition layer permeated by magnetic flux tubes, oriented parallel to each other and alternately connected to the heliosheath or the interstellar regions.

  16. Disinfection of Biofilms in Tubes with Ultraviolet Light

    DEFF Research Database (Denmark)

    Bak, Jimmy; Begovic, Tanja

    2009-01-01

    Bacterial biofilms on long-term catheters are a major source of infection. We demonstrate here the potential of UVC light emitting diodes (LED) for disinfection purposes in catheter like tubes contaminated with biofilm. We show that UVC Light propagation is possible through teflon tubes using...... that the UVC light attenuation inside the tube can be described by an exponential function depending of tube length and various loss mechanisms. The disinfection efficiency of the UVC diodes is demonstrated on tubes contaminated artificially with a Pseudomonas aeruginosa biofilm. The tubes were connected....../ml. The disinfection rates obtained were to close to 100 % (detection limit: 10 CFU/ml). Based on the our investigations we conclude that there is a potential of using LED UVC light sources for disinfection of tubes with thin or transparent biofilms....

  17. Quasistatic Modeling of Concentric Tube Robots with External Loads.

    Science.gov (United States)

    Lock, Jesse; Laing, Genevieve; Mahvash, Mohsen; Dupont, Pierre E

    2010-12-03

    Concentric tube robots are a subset of continuum robots constructed by combining pre-curved elastic tubes. As the tubes are rotated and translated with respect to each other, their curvatures interact elastically, enabling control of the robot's tip configuration as well as the curvature along its length. This technology is projected to be useful in many types of minimally invasive medical procedures. Because these robots are flexible by design, they deflect considerably when applying forces to the external environment. Thus, in contrast to rigid-link robots, their kinematic and static force models are coupled. This paper derives a multi-tube quasistatic model that relates tube rotations and translations together with externally applied loads to robot shape and tip configuration. The model can be applied in robot design, procedure planning as well as control. For validation, the multi-tube model is compared experimentally to a computationally-efficient single-tube approximate model.

  18. Deadly pressure pneumothorax after withdrawal of misplaced feeding tube

    DEFF Research Database (Denmark)

    Andresen, Erik Nygaard; Frydland, Martin; Usinger, Lotte

    2016-01-01

    BACKGROUND: Many patients have a nasogastric feeding tube inserted during admission; however, misplacement is not uncommon. In this case report we present, to the best of our knowledge, the first documented fatality from pressure pneumothorax following nasogastric tube withdrawal. CASE PRESENTATION......: An 84-year-old Caucasian woman with dysphagia and at risk of aspiration underwent routine insertion of a nasogastric feeding tube; however, shortly after insertion she developed respiratory distress. A chest X-ray showed the tube had been misplaced into our patient's right lung. The tube was removed......, but our patient died less than an hour after withdrawal. The autopsy report stated that cause of death was tension pneumothorax, which developed following withdrawal of the misplaced feeding tube. CONCLUSIONS: The indications for insertion of nasogastric feeding tubes are many and the procedure...

  19. 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.

  20. Virtual Community Based Destination Marketing with YouTube

    DEFF Research Database (Denmark)

    Sambhanthan, Arunasalam; Thelijjagoda, Samantha; Good, Alice

    2016-01-01

    YouTube has now evolved into a powerful medium for social interaction. Utilizing YouTube for enhancing marketing endeavours is a strategy practiced by marketing professionals across several industries. This paper rationalizes on the different strategies of leveraging YouTube-based platforms for e...... are reported under the five broad clusters of virtual communities. More broadly, the typology of virtual communities is adapted to evaluate the YouTube platform for effective destination marketing.......YouTube has now evolved into a powerful medium for social interaction. Utilizing YouTube for enhancing marketing endeavours is a strategy practiced by marketing professionals across several industries. This paper rationalizes on the different strategies of leveraging YouTube-based platforms...

  1. Particle-scale simulation of fluidized bed with immersed tubes

    Institute of Scientific and Technical Information of China (English)

    Yongzhi ZHAO; Maoqiang JIANG; Yi CHENG

    2008-01-01

    In order to simulate gas-solids flows with complex geometry,the boundary element method was incorporated into the implementation of a combined model of computational fluid dynamics and discrete element method.The resulting method was employed to simulate hydrodynamics in a fluidized bed with immersed tubes.The transient simulation results showed particle and bubble dynamics.The bubble coalescence and break-up behavior when passing the immersed tubes was successfully predicted.The gas-solid flow pattern in the fluidized bed is changed greatly because of the immersed tubes.As particles and gas are come in contact with the immersed tubes,the gas bubbles will be deformed.The collisions between particles arid tubes will make the tubes sur-rounded by air pockets most of the time and this is unfavorable for the heat transfer between particles and tubes.

  2. Fabrication of stainless steel clad tubing. [gas pressure bonding

    Science.gov (United States)

    Kovach, C. W.

    1978-01-01

    The feasibility of producing stainless steel clad carbon steel tubing by a gas pressure bonding process was evaluated. Such a tube product could provide substantial chromium savings over monolithic stainless tubing in the event of a serious chromium shortage. The process consists of the initial assembly of three component tubesets from conventionally produced tubing, the formation of a strong metallurgical bond between the three components by gas pressure bonding, and conventional cold draw and anneal processing to final size. The quality of the tubes produced was excellent from the standpoint of bond strength, mechanical, and forming properties. The only significant quality problem encountered was carburization of the stainless clad by the carbon steel core which can be overcome by further refinement through at least three different approaches. The estimated cost of clad tubing produced by this process is greater than that for monolithic stainless tubing, but not so high as to make the process impractical as a chromium conservation method.

  3. Parsimonious evaluation of concentric-tube continuum robot equilibrium conformation.

    Science.gov (United States)

    Rucker, Daniel Caleb; Webster Iii, Robert J

    2009-09-01

    Dexterous at small diameters, continuum robots consisting of precurved concentric tubes are well-suited for minimally invasive surgery. These active cannulas are actuated by relative translations and rotations applied at the tube bases, which create bending via elastic tube interaction. An accurate kinematic model of cannula shape is required for applications in surgical and other settings. Previous models are limited to circular tube precurvatures, and neglect torsional deformation in curved sections. Recent generalizations account for arbitrary tube preshaping and bending and torsion throughout the cannula, providing differential equations that define cannula shape. In this paper, we show how to simplify these equations using Frenet-Serret frames. An advantage of this approach is the interpretation of torsional components of the preset tube shapes as "forcing functions" on the cannula's differential equations. We also elucidate a process for numerically solving the differential equations, and use it to produce simulations illustrating the implications of torsional deformation and helical tube shapes.

  4. Heat transfer enhancement through inner grooved copper tubes with different tube parameters

    Directory of Open Access Journals (Sweden)

    M. M. Rahman, Y. M. Ling, G. W. Soon, G. A. Kuan

    2012-01-01

    Full Text Available This paper presents the evaluation of heat transfer coefficients for the flow of R22 through internally grooved copper tubes. A series of tests were conducted using two types of tubes namely Tube A and Tube B, which have different tube parameters. The straight and horizontal test section of the test apparatus with a length of 3.67 m was heated or cooled by water circulated in a surrounding annulus. Condensation tests were conducted at mass flux rates of 180 to 537 kg/m2s and the vapor qualities ranged from a nominal value of 83% at the test section inlet to 6% at the outlet. Evaporation tests were conducted at mass flux rates of 110 to 404 kg/m2s and the nominal vapor qualities at the inlet and outlet were 0 and 85%, respectively. For both the condensation and evaporation tests, the heat transfer coefficients are found to increase as the mass flux rate increases.

  5. 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

  6. 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

  7. Myringotomy versus ventilation tubes in secretory otitis media: eardrum pathology, hearing, and eustachian tube function 25 years after treatment

    DEFF Research Database (Denmark)

    Caye-Thomasen, P.; Stangerup, S.E.; Jorgensen, G.

    2008-01-01

    . At the last evaluation, the eustachian tube function was evaluated by the 9-step test. RESULTS: 1) Myringosclerosis and late atrophy were more prevalent in tube ears. 2) Prevalence of eardrum retraction decreased over time, whereas that of sclerosis remained unchanged in tube ears and increased in myringotomy...... ears. 3) Prevalence of atrophy increased over time in tube ears. 4) Extension of myringosclerosis increased, whereas that of atrophy and tensa retraction decreased over time, regardless of treatment. 5) Hearing was better in the tube ear during, but not after treatment. 6) Tympanometric findings were...

  8. CFD simulation of the gas flow in a pulse tube cryocooler with two pulse tubes

    Science.gov (United States)

    Yin, C. L.

    2015-12-01

    In this paper, in order to instruct the next optimization work, a two-dimension Computational Fluid Dynamics (CFD) model is developed to simulate temperature distribution and velocity distribution of oscillating fluid in the DPTC by individual phase-shifting. It is found that the axial temperature distribution of regenerator is generally uniform and the temperatures near the center at the same cross setion of two pulse tubes are obviously higher than their near wall temperatures. The wall temperature difference about 0-7 K exists between the two pulse tubes. The velocity distribution near the center of the regenerator is uniform and there is obvious injection stream coming at the center of the pulse tubes from the hot end. The formation reason of temperature distribution and velocity distribution is explained.

  9. Self-shielding flex-circuit drift tube, drift tube assembly and method of making

    Energy Technology Data Exchange (ETDEWEB)

    Jones, David Alexander

    2016-04-26

    The present disclosure is directed to an ion mobility drift tube fabricated using flex-circuit technology in which every other drift electrode is on a different layer of the flex-circuit and each drift electrode partially overlaps the adjacent electrodes on the other layer. This results in a self-shielding effect where the drift electrodes themselves shield the interior of the drift tube from unwanted electro-magnetic noise. In addition, this drift tube can be manufactured with an integral flex-heater for temperature control. This design will significantly improve the noise immunity, size, weight, and power requirements of hand-held ion mobility systems such as those used for explosive detection.

  10. Techno-economic analysis of single U-tube and double U-tube heat exchangers in Chongqing area

    Institute of Scientific and Technical Information of China (English)

    王勇; 郭凯生; 田荣; 韩传璞; 赖道新; 徐峰

    2009-01-01

    On the basis of practical projects in Chongqing,the thermal performance of heat exchangers (single U-tube type and double U-tube type) of the ground-source heat pump (GSHP) system in the hot summer was obtained and analyzed. The data obtained from test could match with the result deduced from theoretical calculation. From the test results,the cooling capacity of double U-tube is 1.6 times that of single U-tube. Taking cost per depth per watt Clq as the evaluation standard,Clq of single U-tube is 4.69 RMB$/W,and Clq of double U-tube is 3.14 RMB$/W. The double U-tube heat exchangers usage should be prioritized.

  11. Pneumatic tube-transported blood samples in lithium heparinate gel separator tubes may be more susceptible to haemolysis than blood samples in serum tubes.

    Science.gov (United States)

    Böckel-Frohnhöfer, Nicole; Hübner, Ulrich; Hummel, Björn; Geisel, Jürgen

    2014-10-01

    Pneumatic tube systems are widely used in hospitals. Advantages are high speed and rapid availability of the samples. However, the transportation by pneumatic tube promotes haemolysis. Haemolysis interferes with many spectrophotometric assays and is a common problem in clinical laboratories. The haemolysis index (HI) as a semi-quantitative representation of the level of haemolysis was compared in unpaired tube-transported and hand-delivered routine lithium heparinate plasma samples (n = 1368 and n = 837, respectively). Additionally, the HI distribution was measured in lithium heparinate plasma samples with a HI above the threshold value of 20 and in paired serum samples after transportation by pneumatic tube system. HI values above 20 can interfere with the selected assays: Creatine kinase (CK), creatine kinase-MB (CK-MB) and alanine aminotransferase (ALT) activities. These parameters were determined to demonstrate how haemolysis affects the results. 17.5% of the tube-transported plasma samples and 2.6% of the hand-delivered plasma samples had a HI above 20. The median HI in pneumatic tube-transported lithium heparinate plasma was 85 and 33 in the paired serum samples. The median HI difference between paired plasma and serum was 46. Blood samples in lithium heparinate tubes may be substantially more susceptible to haemolysis by pneumatic tube transportation than serum tube samples. Although our results cannot be universally applied to laboratories with different pneumatic tube systems, it is recommended that each laboratory evaluate carefully the degree of haemolysis after the transportation by the own pneumatic tube system and in terms of the sample type.

  12. Separation of gaseous hydrogen from a water-hydrogen mixture in a fuel cell power system operating in a weightless environment

    Science.gov (United States)

    Romanowski, William E. (Inventor); Suljak, George T. (Inventor)

    1989-01-01

    A fuel cell power system for use in a weightless environment, such as in space, includes a device for removing water from a water-hydrogen mixture condensed from the exhaust from the fuel cell power section of the system. Water is removed from the mixture in a centrifugal separator, and is fed into a holding, pressure operated water discharge valve via a Pitot tube. Entrained nondissolved hydrogen is removed from the Pitot tube by a bleed orifice in the Pitot tube before the water reaches the water discharge valve. Water discharged from the valve thus has a substantially reduced hydrogen content.

  13. Heat Transfer Studies in Tube Banks with Integral Wake Splitters

    Directory of Open Access Journals (Sweden)

    Suzairin Md Seri

    2009-09-01

    Full Text Available This paper reports the findings from heat transfer studies with the presence of extended surfaces from tube banks which are termed as integral wake splitter plates. Employing this type of fins, investigations on heat transfer characteristics on a single circular tube as well as tube banks were carried out in cross flow of air in a rectangular duct. Experiments were carried out in the Reynolds number range 5 x 103 to 105 on a single cylinder of various splitter length-to-tube diameter ratios, L/D = 0.5, 1.0, 1.5 and 2.0. Further, tube banks consisting of 12 rows and 3 tubes per row in equilateral triangle arrangements with transverse pitch to diameter ratio, a = 2, were also investigated, the banks being made up of plain tubes or tubes with splitters. Heat transfer characteristics were studied for tubes with L/D = 0, 0.5 and 1.0 under constant heat flux conditions. Tube banks with L/D = 1.0 yielded the highest heat transfer rates. Findings from this work may be adopted to be utilized in various industrial applications such as economizer of a steam boiler, air-conditioning coils or waste heat recovery systems.

  14. A preliminary investigation of the neoprene tube finger extension splint.

    Science.gov (United States)

    Clark, E N

    1997-01-01

    Neoprene tube finger extension splints were analyzed to determine the production, amounts, and directions of force magnitude on the proximal interphalangeal joint during the flexing of the tube up to angles of 80 degrees. The tubes were examined in their empty form, with a human digit inserted into the tube, and with portions of the tube on the volar and dorsal surfaces removed. Upward forces ranged from less than 100 g to 225 g in the empty tubes. Upon insertion of a human digit into the tubes, forces increased from 125 g at 10 degrees to 650 g at 80 degrees flexion. Removal of a 2-cm square portion on the dorsal surface over the PIP joint did not significantly affect the tube's ability to lift upward demonstrating little or no downward pressure in the device. The tube had little or no upward force following removal of a 2-cm square encompassing the angle of the device on the volar surface. Positive effectiveness of the tubes were examined in case reports.

  15. Visual beam tube inspection at the TRIGA reactor Vienna

    Energy Technology Data Exchange (ETDEWEB)

    Boeck, H.; Musilek, A.; Villa, M. [Vienna University of Technology, Atominstitut of the Austrian Universities, Vienna (Austria)], E-mail: boeck@ati.ac.at

    2006-07-01

    Of the four TRIGA beam tubes two have been visually inspected in 1985. Prior to the inspection the reactor was shut down for 3 weeks. The fuel elements around the beam tubes were removed. Stainless steel dummy elements were inserted in the fuel positions to shield the core radiation. The active part of the Fast Rabbit Tube was removed into the beam tube loading device and transferred to an interim storage: Front dose rate was {approx} 50 mSv/h. Generally the beam tube was very clean, after the last inspection about 30 years ago. A1 cm cut was observed at the beam tube front end. A rigid endoscope was used to check the beam tube's inner surface using a 90 degree deflection objective and photo- and video equipment. The direct dose rate in front of the beam tube was about 30 mSv/h. The beam tube was vacuum cleaned. A corroded shielding tank containing boric acid has leaked. A wooden collimator partially disintegrating due to extreme temperature was removed from beam tube D. Documentation of the inspection for visible defects is produced for later comparison.

  16. Experiments with micro-fin tube in single phase

    Energy Technology Data Exchange (ETDEWEB)

    Copetti, J.B.; Macagnan, M.H.; De Souza, D.; Oliveski, R.D.C. [Universidade do Vale do Rio dos Sinos, Sao Leopoldo (Brazil). Department of Mechanical Engineering

    2004-12-01

    This work shows heat transfer and friction characteristics for water single-phase flow in micro-fin tubes. The analysis of thermal and hydraulic behavior from a laminar to a turbulent flow was carried out in an experimental setup with a 9.52 mm diameter micro-fin tube. The tube was wrapped up with an electrical resistance tape to supply a constant heat flux to its surface. Different operational conditions were considered in the heating tests. The inlet and outlet temperatures, differential wall temperatures along the tube, pressure drop and flow rate were measured. The relationships of heat flux and flow rate with heat transfer coefficient and pressure drop were analyzed. Under the same conditions, comparative experiments with an internally smooth tube were conducted. The micro-fin tube provides higher heat transfer performance than the smooth tube (in turbulent flow h{sub micro-fin}/h{sub smooth}=2.9). In spite of the increase in pressure drop ({delta}p{sub micro-fin}/{delta}p{sub smooth}=1.7) the heat transfer results were significantly higher (about 80%). This shows the advantages of this enhanced configuration in thermal performance related to conventional tubes. The smooth tube results were validated by the comparison with the Dittus-Boelter and Gnielinski correlations. For the micro-fin tube an empirical correlation to the heat transfer coefficient adjusted from the set of measured data is proposed. The values obtained are in conformity with experimental results. (author)

  17. Accurate measurement method for tube's endpoints based on machine vision

    Science.gov (United States)

    Liu, Shaoli; Jin, Peng; Liu, Jianhua; Wang, Xiao; Sun, Peng

    2017-01-01

    Tubes are used widely in aerospace vehicles, and their accurate assembly can directly affect the assembling reliability and the quality of products. It is important to measure the processed tube's endpoints and then fix any geometric errors correspondingly. However, the traditional tube inspection method is time-consuming and complex operations. Therefore, a new measurement method for a tube's endpoints based on machine vision is proposed. First, reflected light on tube's surface can be removed by using photometric linearization. Then, based on the optimization model for the tube's endpoint measurements and the principle of stereo matching, the global coordinates and the relative distance of the tube's endpoint are obtained. To confirm the feasibility, 11 tubes are processed to remove the reflected light and then the endpoint's positions of tubes are measured. The experiment results show that the measurement repeatability accuracy is 0.167 mm, and the absolute accuracy is 0.328 mm. The measurement takes less than 1 min. The proposed method based on machine vision can measure the tube's endpoints without any surface treatment or any tools and can realize on line measurement.

  18. Accurate Measurement Method for Tube's Endpoints Based on Machine Vision

    Institute of Scientific and Technical Information of China (English)

    LIU Shaoli; JIN Peng; LIU Jianhua; WANG Xiao; SUN Peng

    2017-01-01

    Tubes are used widely in aerospace vehicles,and their accurate assembly can directly affect the assembling reliability and the quality of products.It is important to measure the processed tube's endpoints and then fix any geometric errors correspondingly.However,the traditional tube inspection method is time-consuming and complex operations.Therefore,a new measurement method for a tube's endpoints based on machine vision is proposed.First,reflected light on tube's surface can be removed by using photometric linearization.Then,based on the optimization model for the tube's endpoint measurements and the principle of stereo matching,the global coordinates and the relative distance of the tube's endpoint are obtained.To confirm the feasibility,11 tubes are processed to remove the reflected light and then the endpoint's positions of tubes are measured.The experiment results show that the measurement repeatability accuracy is 0.167 mm,and the absolute accuracy is 0.328 mm.The measurement takes less than 1 min.The proposed method based on machine vision can measure the tube's endpoints without any surface treatment or any tools and can realize on line measurement.

  19. Accurate measurement method for tube's endpoints based on machine vision

    Science.gov (United States)

    Liu, Shaoli; Jin, Peng; Liu, Jianhua; Wang, Xiao; Sun, Peng

    2016-08-01

    Tubes are used widely in aerospace vehicles, and their accurate assembly can directly affect the assembling reliability and the quality of products. It is important to measure the processed tube's endpoints and then fix any geometric errors correspondingly. However, the traditional tube inspection method is time-consuming and complex operations. Therefore, a new measurement method for a tube's endpoints based on machine vision is proposed. First, reflected light on tube's surface can be removed by using photometric linearization. Then, based on the optimization model for the tube's endpoint measurements and the principle of stereo matching, the global coordinates and the relative distance of the tube's endpoint are obtained. To confirm the feasibility, 11 tubes are processed to remove the reflected light and then the endpoint's positions of tubes are measured. The experiment results show that the measurement repeatability accuracy is 0.167 mm, and the absolute accuracy is 0.328 mm. The measurement takes less than 1 min. The proposed method based on machine vision can measure the tube's endpoints without any surface treatment or any tools and can realize on line measurement.

  20. Design Methods for Geotextile Tubes Application in Dike Construction

    Institute of Scientific and Technical Information of China (English)

    YAN Yue; YAN Shu-wang; QIU Chang-lin; ZHENG Gang

    2008-01-01

    The technique of geotextile tubes used to construct dikes for land reclamation has been widely used. The tubes are usually filled with slurry of soil, such as sand, silt or clay. The tensile stress developed in the geotextile during filling the tube is the dominant factor for construction of a safe dike. The existing design methods are good for designing sausage shaped tubes and can not be directly applied for designing flat tubes, which are commonly used in dike construction. This paper presents a procedure that can determine the relationship among the tube size, the pumping pressure, the unit weight of the slurry, and the tensile stress developed in the geotextile during the tube filing. When the tubes are piling up to form the dike, the tubes in the bottom will sustain the load from the weight of the upper ones. A procedure is also developed to calculate the changes of the mechanical and geometrical behavior of the tubes under the load with a similar method. All these approaches have been programmed, which can help dike designers to select the suitable geotextile and determine the profile of the dike.

  1. Comparison of cuffed and uncuffed preformed oral pediatric tracheal tubes.

    Science.gov (United States)

    Weiss, Markus; Bernet, Vera; Stutz, Katharina; Dullenkopf, Alexander; Maino, Paolo

    2006-07-01

    In preformed cuffed tracheal tubes the position of the cuff within the airway is given by its distance to the tube bend placed at the lower teeth. The aim of this study was to compare the design of cuffed and uncuffed preformed pediatric oral tracheal tubes with regard to anatomical landmarks. Complete series of cuffed and uncuffed preformed oral pediatric tracheal tubes sized from internal diameter 3.0-7.0 mm if available were ordered from five different manufacturers. The distance from the bend to the distal tube tip and to the upper border of the cuff were measured and compared with anatomical airway landmarks in the developing child. Between cuffed and uncuffed tracheal preformed tubes up to 37 mm differences in the bend-to-tracheal tube tip distances were found for given age groups. Thus uncuffed preformed tracheal tubes were more at risk for inadvertent endobronchial intubation than cuffed preformed tracheal tubes. Comparison of bend-to-upper border of the cuff distances with teeth-to-vocal cord distances calculated from anatomical data revealed that several of the tracheal tube cuffs become positioned within the subglottic larynx or even within the vocal cords when inserted according to the bend. There is a need for improvement in cuffed preformed pediatric tracheal tubes, namely a standard bend-to-tracheal tube tip distance to allow a safe insertion depth, a short cuff placed on the tube shaft as distally as possible and an intubation depth mark to verify a proper position of the cuff in the trachea.

  2. Fast cooldown coaxial pulse tube microcooler

    Science.gov (United States)

    Nast, T.; Olson, J. R.; Champagne, P.; Roth, E.; Kaldas, G.; Saito, E.; Loung, V.; McCay, B. S.; Kenton, A. C.; Dobbins, C. L.

    2016-05-01

    We report the development and initial testing of the Lockheed Martin first-article, single-stage, compact, coaxial, Fast Cooldown Pulse Tube Microcryocooler (FC-PTM). The new cryocooler supports cooling requirements for emerging large, high operating temperature (105-150K) infrared focal plane array sensors with nominal cooling loads of ~300 mW @105K @293K ambient. This is a sequel development that builds on our inline and coaxial pulse tube microcryocoolers reported at CEC 20137, ICC188,9, and CEC201510. The new FC-PTM and the prior units all share our long life space technology attributes, which typically have 10 year life requirements1. The new prototype microcryocooler builds on the previous development by incorporating cold head design improvements in two key areas: 1) reduced cool-down time and 2) novel repackaging that greatly reduces envelope. The new coldhead and Dewar were significantly redesigned from the earlier versions in order to achieve a cooldown time of 2-3 minutes-- a projected requirement for tactical applications. A design approach was devised to reduce the cold head length from 115mm to 55mm, while at the same time reducing cooldown time. We present new FC-PTM performance test measurements with comparisons to our previous pulse-tube microcryocooler measurements and design predictions. The FC-PTM exhibits attractive small size, volume, weight, power and cost (SWaP-C) features with sufficient cooling capacity over required ambient conditions that apply to an increasing variety of space and tactical applications.

  3. Power Generation Capabilities of Tie Tube Assemblies

    Science.gov (United States)

    Gunn, Stanley V.; Hedstrom, James; Hundal, Rolv

    1994-07-01

    Second generation nuclear thermal rocket engine designs, employing solid core reactors and expander engine cycles, generally rely on some form of nuclear-driven heater to supply the major portion of thermal energy required to preheat the turbine-drive gases. If adequate heat transfer occurs, not only will efficiency-enhancing turbine-inlet temperatures be realized, but sufficient energy will be available to enable engine operation at chamber pressures ranging to at least 2,000 psia. For the case of reactor cores employing prismatic fuel elements, the utilization of tie tube assemblies, as first employed in the core-support subsystem of the Phoebus II reactor, can provide the basis of an array of propellant (hydrogen) preheaters that offer an ample supply of energy and temperature to enable candidate expander engine cycles over a wide range of operating parameters, without reducing the total enthalpy of the core-exit gas and its attendant effect on specific impulse. By modifying the tie tube design concept set forth in LASL's Nuclear Rocket Engine definition study, a powerful, weight and packaging-effective, preheater assembly can be realized. The design features of these tie tube assemblies reflect their functional objectives, core criticality considerations, and space constraints. Since the core pressure and inertial mass loads are carried by these assemblies, the structural tubular element(s) also provide coolant passage(s) for the hydrogen. The transfer of heat to the coolant surfaces is controlled by the effective thermal conductivity of the filler structure and ``insulating sleeves,'' which surround the tubular elements and are in controlled thermal contact with the surrounding core fuel elements. An option exists to further increase the transported heat to the coolant walls by the selective loading of the filler structure, ``insulating sleeves,'' and the moderator annular element with fissionable material.

  4. Solid-particle erosion in the tube end of the tube sheet of a shell-and-tube heat exchanger

    Science.gov (United States)

    Habib, M. A.; Badr, H. M.; Said, S. A. M.; Ben-Mansour, R.; Al-Anizi, S. S.

    2006-03-01

    Erosion is one of the major problems in many industrial processes, and in particular, in heat exchangers. The effects of flow velocity and sand particle size on the rate of erosion in a typical shell-and-tube heat exchanger were investigated numerically using the Lagrangian particle-tracking method. Erosion and penetration rates were obtained for sand particles of diameters ranging from 10 to 500 μm and for inlet flow velocities ranging from 0.197 to 2.95 m/s. A flow visualization experiment was conducted with the objective of verifying the accuracy of the continuous phase calculation procedure. Comparison with available experimental data of penetration rates was also conducted. These comparisons resulted in a good agreement. The results show that the location and number of eroded tubes depend mainly on the particle size and velocity magnitude at the header inlet. The rate of erosion depends exponentially on the velocity. The particle size shows negligible effect on the erosion rate at high velocity values and the large-size particles show less erosion rates compared to the small-size particles at low values of inlet flow velocities. The results indicated that the erosion and penetration rates are insignificant at the lower end of the velocity range. However, these rates were found to increase continuously with the increase of the inlet flow velocity for all particle sizes. The particle size creating the highest erosion rate was found to depend on the flow velocity range.

  5. PHASE CHANGE AROUND A FINNED TUBE

    Directory of Open Access Journals (Sweden)

    Aytunç EREK

    2003-01-01

    Full Text Available This study presents the heat transfer enhancement in the thermal energy storage system by using radially finned tube. The solution of the system consists of the solving the equations of the heat transfer fluid (HTF, the pipe wall and fin, and the phase change material (PCM as one domain. The control volume finite difference approach and the semi implicit solver (SIS are used to solve the equations. Fully developed velocity distribution is taken in the HTF. Flow parameters (Re number and inlet temperature of coolant and fin parameters (the number of fins, fin length, fin thickness are found to influence solidification fronts and the total stored energy.

  6. Floating point processor for photomultiplier tube signals

    Energy Technology Data Exchange (ETDEWEB)

    Baron, P.; Joudon, A.; Lugiez, F.; Rouger, M. [C.E.A. Saclay, Gif sur Yvette (France)

    1995-08-01

    A chip was provided to read out the channels of the Shower Maximum Detector (SMD) in the electromagnetic calorimeter (EMC) of the S.D.C. experiment (solenoidal Detector Collaboration) at the Superconducting Super Collider project and shape of the electromagnetic shower with better precision than can be done by the EMC alone. A fast digital readout system has been designed for synchronous processing of the current signals delivered by a 64-channel multichannel photomultiplier tube (MCPMT) associated with fast scintillators. This mixed analog digital full custom chip uses a 1.2{micro}m A.M.S. CMOS process.

  7. Drift Tube Linac Conditioning of Tank1

    CERN Document Server

    Shafqat, N; Toor, W A

    2014-01-01

    Tank1 of the Drift Tube Linac (DTL) of the Linac4 has been conditioned at the Linac4 tunnel. The tank was tuned for resonance at 352.2 MHz, and stable operation has been achieved with 725 µs long RF pulses at a repetition rate of 1 Hz. The maximum RF level that has been reached is 810 kW with a pulse width of 600 µs. Since this was the first RF structure exclusively conditioned in the Linac4 tunnel with the operation and control software of Linac4, some related issues and limitations had to be taken into account.

  8. 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.

  9. Traveling wave tube and method of manufacture

    Science.gov (United States)

    Vancil, Bernard K. (Inventor)

    2004-01-01

    A traveling wave tube includes a glass or other insulating envelope having a plurality of substantially parallel glass rods supported therewithin which in turn support an electron gun, a collector and an intermediate slow wave structure. The slow wave structure itself provides electrostatic focussing of a central electron beam thereby eliminating the need for focussing magnetics and materially decreasing the cost of construction as well as enabling miniaturization. The slow wave structure advantageously includes cavities along the electron beam through which the r.f. energy is propagated, or a double, interleaved ring loop structure supported by dielectric fins within a ground plane cylinder disposed coaxially within the glass envelope.

  10. The Crystals Cave in a test tube

    Science.gov (United States)

    Puig, C.; Romero, M. L.

    2012-04-01

    It's quite easy to understand formation of crystals in Nature by evaporation of the solutions that contain minerals, but many times we have realised that our pupils hardly understand that precipitation is a process mostly caused by changing parameters in a solution, like pH, temperature, etc. and not necessarily depending on evaporation. We propose a hands-on activity using the context of the Cave of the Crystals in Naica's mine, Mexico. The Crystals Cave is a wonderful place where giant crystals of selenite (gypsum) have grown feeding from a supersaturated anhydrite solution1. Miners discovered the cave filled with hot water, and drained it to explore the gallery. The cave is now a giant laboratory where scientists are looking for the keys to understand geological processes. Teaching sequence (for students 15 years old) is as follows: DISCOVERING A MARVELLOUS PLACE: We showed our pupils several images and a short video of the Cave of the Crystals and ask them about the process that may have caused the phenomenon. Whole-class discussion. PRESENTING A CHALLENGE TO OUR STUDENTS: "COULD WE CREATE A CRYSTALS CAVE IN A TEST TUBE?" EXPERIMENTING TO IMITATE NATURE: Students tried to grow crystals simulating the same conditions as those in Naica's mine. We have chosen KNO3, a salt more soluble than gypsum. We added 85 g of salt to 200 ml of water (solubility of KNO3 at 25°C is 36 g per 100 gr of water) and heated it until it is dissolved. Afterwards, we poured the solution into some test tubes and other recipients and let them cool at room temperature. And they got a beautiful crystals cave!! THINKING A LITTLE MORE: we asked pupils some questions to make them think about the process and to predict what would happen in different situations. For example: a) What would happen with crystals if we heated the tubes again? or b) What would happen if we took the remaining solution from the tubes and keep it in the fridge? PROVING A NEW HYPOTHESIS: Pupils collected the remaining

  11. Fermion confinement by a relativistic flux tube

    CERN Document Server

    Olsson, M G; Williams, K; Olsson, M G; Veseli, S; Williams, K

    1996-01-01

    We formulate the description of the dynamic confinement of a single fermion by a flux tube. The range of validity extends from the relativistic corrections of a slowly moving quark to the ultra-relativistic motion in a heavy-light meson. The reduced Salpeter equation, also known as the no-pair equation, provides the framework for our discussion. The Regge structure is that of a Nambu string with one end fixed. Numerical solutions are found giving very good fits to heavy-light meson masses. The Isgur-Wise function with a zero recoil slope of \\xi'(1)\\simeq -1.23 is obtained.

  12. Electron accelerating unit for streak image tubes

    Indian Academy of Sciences (India)

    Fangke Zong; Qinlao Yang; Houzhi Cai; Li Gu; Xiang Li; Jingjin Zhang

    2015-12-01

    An electron accelerating unit is proposed for use in streak image tubes (SITs). An SIT with this new accelerating unit was simulated using the Monte Carlo method. The simulation results show that the accelerating unit improves both the spatial and temporal resolution. Compared to a traditional SIT, the transit time spread for electrons in the cathode-to-mesh region is reduced from 247 to 162 fs, the line width of the electron beam on the image surface is reduced from 42.7 to 26.1 m, and the temporal resolution is improved from 515 to 395 fs.

  13. Inductive Output Tubes -- Status and Future Direction

    Science.gov (United States)

    Bohlen, Heinz

    2002-08-01

    Invented in 1938, at the same time as the klystron, it took the Inductive Output Tube (IOT) more than 40 years to surface as a useful device. Its progress after that event was rapid. Though plagued by teething problems in the beginning, it has since replaced the klystron as a TV amplifier in UHF, and it holds its own against the solid-state competition in that application. The IOT also shows much promise as a high-power amplifier, but early developments in this direction have remained solitary events so far. The paper discusses the causes and the potential of the device for future high-power applications.

  14. Strong boundedness of analytic functions in tubes

    Directory of Open Access Journals (Sweden)

    Richard D. Carmichael

    1979-01-01

    Full Text Available Certain classes of analytic functions in tube domains TC=ℝn+iC in n-dimensional complex space, where C is an open connected cone in ℝn, are studied. We show that the functions have a boundedness property in the strong topology of the space of tempered distributions g′. We further give a direct proof that each analytic function attains the Fourier transform of its spectral function as distributional boundary value in the strong (and weak topology of g′.

  15. Sound Coiled-Tubing Drilling Practices

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Thomas; Deskins, Greg (Maurer Technology Inc.); Ward, Stephen L. (Advantage Energy Services Ltd); Hightower, Mel

    2001-09-30

    This Coiled-Tubing Drilling (CTD) Sound Practices Manual provides tools needed by CTD engineers and supervisors to plan, design and perform safe, successful CTD operations. As emphasized throughout, both careful planning and attention to detail are mandatory for success. A bibliography of many useful CTD references is presented in Chapter 6. This manual is organized according to three processes: 1) Pre-Job Planning Process, 2) Operations Execution Process, and 3) Post-Job Review Process. Each is discussed in a logical and sequential format.

  16. A two-stage Stirling-type pulse tube cryocooler with a cold inertance tube

    Science.gov (United States)

    Gan, Z. H.; Fan, B. Y.; Wu, Y. Z.; Qiu, L. M.; Zhang, X. J.; Chen, G. B.

    2010-06-01

    A thermally coupled two-stage Stirling-type pulse tube cryocooler (PTC) with inertance tubes as phase shifters has been designed, manufactured and tested. In order to obtain a larger phase shift at the low acoustic power of about 2.0 W, a cold inertance tube as well as a cold reservoir for the second stage, precooled by the cold end of the first stage, was introduced into the system. The transmission line model was used to calculate the phase shift produced by the cold inertance tube. Effect of regenerator material, geometry and charging pressure on the performance of the second stage of the two-stage PTC was investigated based on the well known regenerator model REGEN. Experimental results of the two-stage PTC were carried out with an emphasis on the performance of the second stage. A lowest cooling temperature of 23.7 K and 0.50 W at 33.9 K were obtained with an input electric power of 150.0 W and an operating frequency of 40 Hz.

  17. Practical acoustic thermometry with twin-tube and single-tube sensors

    Energy Technology Data Exchange (ETDEWEB)

    De Podesta, M.; Sutton, G.; Edwards, G.; Stanger, L.; Preece, H. [National Physical Laboratory, Teddington, (United Kingdom)

    2015-07-01

    Accurate measurement of high temperatures in a nuclear environment presents unique challenges. All secondary techniques inevitably drift because the thermometric materials in thermocouples and resistance sensors are sensitive not just to temperature, but also their own chemical and physical composition. The solution is to use primary methods that rely on fundamental links between measurable physical properties and temperature. In the nuclear field the best known technique is the measurement of Johnson Noise in a resistor (See Paper 80 at this conference). In this paper we describe the measurement of temperature in terms of the speed of sound in a gas confined in a tube - an acoustic waveguide. Acoustic thermometry is the most accurate technique of primary thermometry ever devised with the best uncertainty of measurement below 0.001 C. In contrast, the acoustic technique described in this work has a much larger uncertainty, approximately 1 deg. C. But the cost and ease of use are improved by several orders of magnitude, making implementation eminently practical. We first describe the basic construction and method of operation of thermometers using twin-tubes and single tubes. We then present results using a twin-tube design showing that showing long term stability (i.e. no detectable drift) at 700 deg. C over periods of several weeks. We then outline how the technique may be developed for different nuclear applications. (authors)

  18. Determination of the Mechanical Properties of Friction Welded Tube Yoke and Tube Joint

    Directory of Open Access Journals (Sweden)

    Efe Işık

    2016-01-01

    Full Text Available This paper deals with the friction welding of the tube yoke and the tube of the drive shaft used in light commercial vehicles. Tube yoke made from hot forged microalloyed steel and the tube made from cold drawn steel, with a ratio (thickness/outside diameter ratio of less than 0.1, were successfully welded by friction welding method. Hardness distributions on both sides of the welded joint across the welding interface were determined and the microstructure of the joint was investigated. Furthermore, joint strength was tested under tensile, static torsional, and torsional fatigue loadings. The tested data were analyzed by Weibull distribution. The maximum hardness value along the welded joint was detected as 553 Hv1. The lowest detected tensile strength of the joint was 13% less than the base materials’ tensile strength. The torsional load carrying capacity of the friction welded thin walled tubular joint without any damage was obtained as 4.252,5 Nm in 95% confidence interval. After conducting fully reversed torsional fatigue tests, the fatigue life of friction welded tubular joints was detected as 220.066,3 cycles.

  19. Failure of a MEA reclaimer tube bundle due to corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Shaban, H.; Abdo, M.S.E.; Lal, D.P.

    1988-08-01

    The removal of sulphur compounds from natural gas used in ammonia production is carried out by scrubbing with monoethanol amine (MEA). To avoid build up of corrosion and degradation products, a portion of the circulating MEA solution is passed through a reclaimer. This is essentially a kettle-type reboiler with a tube bundle made of 316L stainless steel. Occasional failures of the tube bundle due to pitting corrosion have been reported. It is suggested that the excessive pitting corrosion observed on the upper rows of the tube bundle could be partly due to high steam temperature but mainly due to the liquid level falling below the tubes leaving an accumulation of corrosive degradation products on the exposed surfaces, normally these corrosive products remain diluted in the MEA solution and cause little corrosion of the covered tubes. Their concentration on the dry upper layers of the hot metal tubes, however, leads to excessive corrosion. (U.K.).

  20. Flow and heat transfer of petal shaped double tube

    Science.gov (United States)

    Shakouchi, Toshihiko; Kawashima, Yuki; Tsujimoto, Koichi; Ando, Toshitake

    2014-06-01

    In this study, the flow and heat transfer characteristics of petal-shaped double tube with 6 petals are examined experimentally for a compact heat exchanger. As results, the heat transfer rate, Q, of the 6 petal shaped double tube (6-p tube) is much larger than that, Qp, of conventional circular double tube in all Reynolds number Rein,h (where, the reference length is hydraulic diameter) ranges. For example, at Rein,h =(0.5~1.0)× 104 it is about 4 times of Qp. The heat transfer enhancement of 6-p tube is by the increase of heat transfer area, wetting perimeter, and a highly fluctuating flow, and Q of the 6-p tube can be expressed by Q [kW/m] = 0.54Rein,h + 2245.