WorldWideScience

Sample records for dimpled tube type

  1. Spring/dimple instrument tube restraint

    Science.gov (United States)

    DeMario, E.E.; Lawson, C.N.

    1993-11-23

    A nuclear fuel assembly for a pressurized water nuclear reactor has a spring and dimple structure formed in a non-radioactive insert tube placed in the top of a sensor receiving instrumentation tube thimble disposed in the fuel assembly and attached at a top nozzle, a bottom nozzle, and intermediate grids. The instrumentation tube thimble is open at the top, where the sensor or its connection extends through the cooling water for coupling to a sensor signal processor. The spring and dimple insert tube is mounted within the instrumentation tube thimble and extends downwardly adjacent the top. The springs and dimples restrain the sensor and its connections against lateral displacement causing impact with the instrumentation tube thimble due to the strong axial flow of cooling water. The instrumentation tube has a stainless steel outer sleeve and a zirconium alloy inner sleeve below the insert tube adjacent the top. The insert tube is relatively non-radioactivated inconel alloy. The opposed springs and dimples are formed on diametrically opposite inner walls of the insert tube, the springs being formed as spaced axial cuts in the insert tube, with a web of the insert tube between the cuts bowed radially inwardly for forming the spring, and the dimples being formed as radially inward protrusions opposed to the springs. 7 figures.

  2. Development and Field Trial of Dimpled-Tube Technology for Chemical Industry Process Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Yaroslav Chudnovsky; Aleksandr Kozlov

    2006-10-12

    Most approaches to increasing heat transfer rates in the convection sections of gas-fired process heaters involve the incorporation of fins, baffles, turbulizers, etc. to increase either the heat transfer surface area or turbulence or both. Although these approaches are effective in increasing the heat transfer rates, this increase is invariably accompanied by an associated increase in convection section pressure drop as well as, for heaters firing ‘dirty’ fuel mixtures, increased fouling of the tubes – both of which are highly undesirable. GTI has identified an approach that will increase heat transfer rates without a significant increase in pressure drop or fouling rate. Compared to other types of heat transfer enhancement approaches, the proposed dimpled tube approach achieves very high heat transfer rates at the lowest pressure drops. Incorporating this approach into convection sections of chemical industry fired process heaters may increase energy efficiency by 3-5%. The energy efficiency increase will allow reducing firing rates to provide the required heating duty while reducing the emissions of CO2 and NOx.

  3. Sacral Dimple.

    Science.gov (United States)

    Khairy, Sami; Azzubi, Moutasem

    2017-05-01

    A 5-month-old boy, the product of a normal, spontaneous, uncomplicated vaginal delivery, presented to a peripheral hospital with a 2-month history of recurrent fever, vomiting, seizures, and progressive lower limb weakness. He was discovered to have hydrocephalus secondary to a posterior fossa lesion. An external ventricular drain was inserted, and he was transferred to our hospital. Upon presentation, his head circumference was 45 cm (in the 90th percentile), pupils were equally reactive, and he was quadriparetic with the left side being weaker than the right. Spinal examination revealed a sacral dimple with purulent discharge on digital pressure. Magnetic resonance imaging revealed a brain abscess, a spinal dermoid cyst, and dermal sinus. He underwent craniotomy and abscess evacuation followed by untethering of the spinal cord, resection of the dermoid, and the skin sinus. He tolerated the procedure well, and his weakness improved. The antibiotic course was completed, and the external ventricular drain was removed. Follow-up after 2 years showed a normal neurologic examination. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Acute flaccid paralysis in a patient with sacral dimple

    OpenAIRE

    Mostafa, Mohammed; Nasef, Nehad; Barakat, Tarik; El-Hawary, Amany K; Abdel-Hady, Hesham

    2013-01-01

    Sacral dimples are the most common cutaneous anomaly detected during neonatal spinal examination. Congenital dermal sinus tract, a rare type of spinal dysraphism, occurs along the midline neuraxis from occiput down to the sacral region. It is often diagnosed in the presence of a sacral dimple together with skin signs, local infection, meningitis, abscess, or abnormal neurological examination. We report a case of acute flaccid paralysis with sensory level in a 4 mo old female infant with sacra...

  5. Acute flaccid paralysis in a patient with sacral dimple.

    Science.gov (United States)

    Mostafa, Mohammed; Nasef, Nehad; Barakat, Tarik; El-Hawary, Amany K; Abdel-Hady, Hesham

    2013-08-08

    Sacral dimples are the most common cutaneous anomaly detected during neonatal spinal examination. Congenital dermal sinus tract, a rare type of spinal dysraphism, occurs along the midline neuraxis from occiput down to the sacral region. It is often diagnosed in the presence of a sacral dimple together with skin signs, local infection, meningitis, abscess, or abnormal neurological examination. We report a case of acute flaccid paralysis with sensory level in a 4 mo old female infant with sacral dimple, diagnosed by magnetic resonance imaging to be a paraspinal subdural abscess. Surgical exploration revealed a congenital dermal sinus tract extending from the subdural abscess down to the sacral dimple and open to the exterior with a minute opening.

  6. Effect of the inertance tube on the performance of the Stirling type pulse tube refrigerator

    International Nuclear Information System (INIS)

    Hong, Yong Ju; Park, Seong Je; Kim, Hyo Bong; Kim, Yang Hoon; Choi, Young Don

    2002-01-01

    The Pulse Tube Refrigerator(PTR), which has no moving parts at its cold section, is attractive for obtaining higher reliability, simpler construction and lower vibration than in any other small cryocoolers. Commonly used mean to achieve optimum performance of the PTR are orifice or inertance tube. The Stirling type Pulse Tube Refrigerator in the experiments consists of a compressor driven by linear motors, which make pressure waves, a regenerator, a pulse tube with inertance tube, and a buffer. The pressures and temperature are measured to explore the dependency of inertance tube on the performance of the PTR. The results show the dependency of cool-down characteristics, no-load temperature on frequency of operation and inertance tube

  7. Investigation of the Effect of Dimple Bionic Nonsmooth Surface on Tire Antihydroplaning

    Directory of Open Access Journals (Sweden)

    Haichao Zhou

    2015-01-01

    Full Text Available Inspired by the idea that bionic nonsmooth surfaces (BNSS reduce fluid adhesion and resistance, the effect of dimple bionic nonsmooth structure arranged in tire circumferential grooves surface on antihydroplaning performance was investigated by using Computational Fluid Dynamics (CFD. The physical model of the object (model of dimple bionic nonsmooth surface distribution, hydroplaning model and SST k-ω turbulence model are established for numerical analysis of tire hydroplaning. By virtue of the orthogonal table L16(45, the parameters of dimple bionic nonsmooth structure design compared to the smooth structure were analyzed, and the priority level of the experimental factors as well as the best combination within the scope of the experiment was obtained. The simulation results show that dimple bionic nonsmooth structure can reduce water flow resistance by disturbing the eddy movement in boundary layers. Then, optimal type of dimple bionic nonsmooth structure is arranged on the bottom of tire circumferential grooves for hydroplaning performance analysis. The results show that the dimple bionic nonsmooth structure effectively decreases the tread hydrodynamic pressure when driving on water film and increases the tire hydroplaning velocity, thus improving tire antihydroplaning performance.

  8. A novel tribological study on DLC-coated micro-dimpled orthopedics implant interface.

    Science.gov (United States)

    Choudhury, Dipankar; Urban, Filip; Vrbka, Martin; Hartl, Martin; Krupka, Ivan

    2015-05-01

    This study investigates a tribological performance of diamond like carbon (DLC) coated micro dimpled prosthesis heads against ceramic cups in a novel pendulum hip joint simulator. The simulator enables determining friction coefficient and viscous effects of a concave shaped specimen interface (conformal contact). Two types of DLC such as hydrogenated amorphous carbon (a-C:H) and tetrahedral amorphous carbon (Ta-C) and one set of micro dimple (diameter of 300µm, depth of 70µm, and pitch of 900µm) were fabricated on metallic prosthesis heads. The experiment results reveal a significant friction coefficient reduction to the 'dimpled a-C:H/ceramic' prosthesis compared to a 'Metal (CoCr)/ceramic' prosthesis because of their improved material and surface properties and viscous effect. The post-experiment surface analysis displays that the dimpled a-C:H yielded a minor change in the surface roughness, and generated a larger sizes of wear debris (40-200nm sized, equivalent diameter), a size which could be certainly stored in the dimple, thus likely to reducing their possible third body abrasive wear rate. Thus, dimpled a:C-H can be used as a 'metal on ceramic hip joint interface', whereas the simulator can be utilized as an advanced bio-tribometer. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Panel type X-ray image intensifier tube

    International Nuclear Information System (INIS)

    Wang, S.P.

    1977-01-01

    A panel shaped, proximity type, X-ray image intensifier tube for medical X-ray diagnostic is disclosed. It has all linear components and yet a high brightness gain, in the range of 500 to 20,000 cd-sec/m 2 -R, the tube being comprised of a rugged metallic tube envelope, an inwardly concave metallic input window of full size output display screen, an alkaline-halide scintillator photocathode screen suspended on insulators within the envelope and in between the input window and the output screen, and a high Z glass output window to reduce X-ray backscatter inside and outside of the tube. An X-ray sensitive photographic camera for medical diagnostic use is also disclosed which includes an X-ray sensitive image intensifier means of the proximity type and a reduction type optical system having an effective foral length in excess of 100mm for focusing the emage generated on the output display screen of the image intensifier tube onto a small size but directly viewable photographic film. The parameters of the image intensifier, the optics and the film are specified and linked to each other in a manner which maximizes the image quality for a camera system of this type and at the same time restricts the system speed of the camera to a range of 500 to 5,000 R -1 for the film to achieve a net density of 1.0. (Auth.)

  10. A parabolic model for dimple potentials

    International Nuclear Information System (INIS)

    Aydin, Melike Cibik; Uncu, Haydar; Deniz, Coskun

    2013-01-01

    We study the truncated parabolic function and demonstrate that it is a representation of the Dirac δ function. We also show that the truncated parabolic function, used as a potential in the Schrödinger equation, has the same bound state spectrum, tunneling and reflection amplitudes as the Dirac δ potential, as the width of the parabola approximates to zero. Dirac δ potential is used to model dimple potentials which are utilized to increase the phase-space density of a Bose–Einstein condensate in a harmonic trap. We show that a harmonic trap with a δ function at the origin is a limiting case of the harmonic trap with a symmetric truncated parabolic potential around the origin. Hence, the truncated parabolic is a better candidate for modeling the dimple potentials. (paper)

  11. Direct view panel type X-ray image intensifier tube

    International Nuclear Information System (INIS)

    Yang, S.-P.; Robbins, C.D.; Merrit, E.

    1977-01-01

    A panel shaped, proximity type, X-ray image intensifier tube for medical X-ray fluoroscopy use is described. It has all linear components and yet a high brightness gain, in excess of 4,000 cd-sec/m 2 -R, the tube being comprised of a rugged metallic tube envelope, an inwardly concave metallic input window, a directly viewable full size output display screen, and a scintillator-photocathode screen having a thickness of at least 200 microns for a high X-ray photon utilization ability as well as X-ray stopping power, the scintillator-photocathode screen being suspended on insulators within the envelope and in between the input window and the output screen. The scintillator-photocathode screen is spaced from the output screen by at least 8mm to allow the application of a high negative potential at the scintillator-photocathode screen with respect to the output screen for high gain with low field emission, since all of the remaining components within the tube envelope are at neutral potential with respect to the output display screen. (Auth.)

  12. A new simple technique for making facial dimples.

    Science.gov (United States)

    Bao, Shiwei; Zhou, Chuande; Li, Senkai; Zhao, Muxin

    2007-01-01

    In Asia, especially in China, women think a dimple is an important part of a beautiful smiling face. The dimple can make them more confident. Unfortunately, not all women have dimples. Hence, with the development of the Chinese economy, there is an increasing demand among Chinese women for the creation of dimples. Most women hope the impairment of the operation will be slight and the period of recovery short so they can go to work as quickly as possible. Some of them want to have dimples only when they smile. The authors have used a new simple technique to form 56 dimples for 36 women. During the operation, they use a syringe needle to guide a monofilament nylon suture through the dermis and the active facial muscles (usually the buccinator). A sling is formed between the skin and the buccinator muscle. The knot is tied, and the dimple is created. After the operation, patients have been satisfied with the shape of the dimples. Furthermore, hematoma and infection never occurred. As a result, on the basis of their experience, the authors conclude that this technique is simple and easy to duplicate. Moreover, this technique has many benefits. For example, with this procedure, it is easy to adjust the bulk of dimples by adjusting the tension of the knot and the amount of dermis tissue the injection needle sutures. Because no tissue is resected, there is mild postoperative swelling. Consequently, patients can return to work or other activities 2 days after the operation.

  13. Core construction in a pressure tube type heavy water reactor

    International Nuclear Information System (INIS)

    Ueda, Makoto; Aoki, Katsutada.

    1975-01-01

    Object: To replace a centrally positioned fuel assembly of a fuel assembly unit with a reactor controlling machinery to decrease a distance between the fuel assemblies thereby saving use of heavy water and enhancing economy. Structure: A centrally positioned fuel assembly of a fuel assembly unit, which is composed of a plurality of fuel assemblies orderly arranged in lattice fashion, is replaced with a reactor controlling members such as control rods, poison tubes and the like to provide an arrangement of lattice-free type fuel assembly, thus reducing the pitch as small as possible. (Kamimura, M.)

  14. Sleeve type repair of degraded nuclear steam generator tubes

    International Nuclear Information System (INIS)

    Ayres, P.S.; Stark, L.E.; Feldstein, J.G.; Fu, T.

    1986-01-01

    A sealable sleeve is described for insertion into the repair of a degraded tube which consists of: a hollow core inner member of the same material as the degraded tube; a thinner outer member of substantially pure nickel and resistant to corrosive attack, the outer member being metallurgically bonded with the inner member; an expanded portion of the sleeve at one end for positioning in the tube within a tube sheet; a multiplicity of grooves formed in and adjacent to the other end of the sleeve which extends into the free-standing portion of the tube beyond the tube sheet, and a noble metal braze material contained in the grooves

  15. Facial dimple creation surgery: A review of literature

    Directory of Open Access Journals (Sweden)

    M Kiran Kumar

    2017-01-01

    Full Text Available Cosmetic surgery is not a new thing. The boom of cosmetic surgery is at its pace in India; people have been getting habituated to esthetics for so many years. Esthetic adjustment of various body parts such as rhinoplasty and lip modifications are more common nowadays. A dimple is a small depression on the surface of the body which can be easily noticeable; people appreciate the presence of dimple on the face and believe that it is a sign of good fortune and prosperity. With the advancements in the cosmetic surgery, there has been a upsurge in having artificial dimple on face. With this increased demand in having facial dimples in people, surgeons now are in an idea of creating an artificial dimple with dimple surgery or “dimpleplasty.” The procedure of dimpleplasty is as simple as making a cut in the skin, suturing the underside of the skin to a deeper layer to create a small depression. The suture creates a permanent scar which maintains the dimple. It is a thumb rule that any surgery has minor risks which are avoidable; the current review enumerates the various procedures for dimpleplasty and their outcomes. This article emphasizes on routine as well as recent procedures used for dimpleplasty and its relative complications.

  16. Nanoscale dimples for improved absorption in organic solar cells

    DEFF Research Database (Denmark)

    Goszczak, Arkadiusz Jaroslaw; Rubahn, Horst-Günter; Madsen, Morten

    Organic solar cells (OSC’s) have attracted much attention in the past years due to their potential low-cost, light-weight and mechanical flexibility. A method for improving the power conversion efficiencies of the devices is by incorporating structured electrodes in the solar cell architecture, a...... ordered and discorded dimple arrangement and their contribution to light management is presented. Such dimples can later be employed to fabricate nanostructured electrodes in P3HT/PCBM organic solar cells....

  17. Aerodynamic effects of dimples on soccer ball surfaces.

    Science.gov (United States)

    Hong, Sungchan; Asai, Takeshi

    2017-10-01

    Recently, the shape and design of the panel on the official ball used in the FIFA World Cup was considerably different from that of a conventional soccer ball (having 32 pentagonal and hexagonal panels). Depending on the number of different panels and their orientation, the aerodynamic force experienced by a ball is believed to change, which in turn changes the ball trajectory. However, not much is known about the impact of the surface forms of a ball on its aerodynamics. Therefore, in the present study, 10 different types of soccer balls were produced and their aerodynamic properties were studied by wind tunnel experiments. The results confirmed that the aerodynamic force acting on the ball varied considerably depending on the existence of dimples on the ball surface. In addition, the 4 types of soccer balls, which had different kinds of roughness, revealed that even balls having the same number and shapes of panels experienced greatly varying aerodynamic forces depending on the surface form of the balls.

  18. CFD simulation of dimpled sphere and its wind tunnel verification

    Directory of Open Access Journals (Sweden)

    Spálenský Vojtěch

    2017-01-01

    Full Text Available Paper deals with problems of CFD simulating airflow over a dimpled spherical surface and its verification by the wind tunnel measurement. The low-cost simulation approach was applied to be run on a common PC using the commercial software ANSYS CFX. The wind tunnel testing has been performed in the laboratory of aerodynamics at the Department of Air Force and Aircraft Technology of the University of Defence. Measured results of the drag coefficient versus the Reynolds number for smooth and dimpled spheres were compared and discussed. Presented simulation corresponds adequately to the experimental results. It can be stated that the CFD simulation is suitable for simulating the flow over the dimpled surfaces similar to sphere.

  19. Friction characteristics for density of micro dimples using photolithography

    International Nuclear Information System (INIS)

    Chae, Young Jun; Kim, Seock Sam

    2005-01-01

    Surface texturing of tribological application is another attractive technology of friction reducing. Also, reduction of friction is therefore considered to be a necessary requirement for improved efficiency of machine. In this paper attempts to investigate the effect of density for micro-scale dimple pattern using photolithography on bearing steel flat mated with pin-on-disk. We demonstrated the lubrication mechanism for a Stribeck curve, which has a relationship between the friction coefficient and a dimensionless parameter for lubrication condition. It is found that friction coefficient is depended on the density of surface pattern. It was thus verified that micro-scale dimple could affect the friction reduction considerably under mixed and hydrodynamic lubrication conditions from based on friction map. Lubrication condition regime has an influence on the friction coefficient induced the density of micro dimple

  20. Templated growth of gold satellites on dimpled silica cores.

    Science.gov (United States)

    Chomette, C; Duguet, E; Mornet, S; Yammine, E; Manoharan, V N; Schade, N B; Hubert, C; Ravaine, S; Perro, A; Tréguer-Delapierre, M

    2016-10-06

    We synthesize robust clusters of gold satellites positioned with tetrahedral symmetry on the surface of a patchy silica core by adsorption and growth of gold on the patches. First we conduct emulsion polymerization of styrene in the presence of 52 nm silica seeds whose surface has been modified with methacryloxymethyltriethoxysilane (MMS). We derive four-dimple particles from the resulting silica/polystyrene tetrapods. Polystyrene chains are covalently bound to the silica surface within the dimples due to the MMS grafts and they may be thiolated to induce adsorption of 12 nm gold particles. Using chloroauric acid, ascorbic acid and sodium citrate at room temperature, we grow gold from these 12 nm seeds without detachment from or deformation of the dimpled silica surface. We obtain gold satellites of tunable diameter up to 140 nm.

  1. Type I collagen from bullfrog (Rana catesbeiana) fallopian tube

    African Journals Online (AJOL)

    Jane

    2011-08-08

    Aug 8, 2011 ... Ultraviolet–visible spectroscopy (UV-vis) spectra. PSC sample was dissolved in 0.5 M acetic acid to obtain a concen- tration of 2 g/l. The UV-vis adsorption spectra of bullfrog fallopian tube collagen were recorded by a Hitachi spectrophotometer UV-. 2010 (Hitachi, Tokyo, Japan) from 200 to 400 nm and a ...

  2. Research on the application of vortex tube type of cooling jacket in coal mine

    Science.gov (United States)

    Zhai, Xiaojie

    2017-08-01

    The problem of heat damage in high temperature mine has been attached more and more concern to. In addition, the existing solutions also have problems which are large initial investment and poor safety performance. Vortex tube type of mine cooling jacket, studied in this paper, using vortex tube refrigeration principle. It used compressed exhaust gas as the gas source, which can solve the problem of the large-scale cooling equipment which rely on electricity, and may not emit toxic gases at the same time. Thereby, by using the method of observation and questionnaire survey, the parameters of the vortex tube were optimized for optimal cooling effect. In conclusion, the features of security, reliability, energy saving and environmental protection can be realized by the vortex tube type of cooling jacket. What's more important, we had investigated the feasibility of the application of vortex tube type of mine cooling jacket.

  3. Design and test of the Stirling-type pulse tube cryocooler

    Science.gov (United States)

    Hong, Yong-Ju; Ko, Junseok; Kim, Hyo-Bong; Yeom, Han-Kil; In, Sehwan; Park, Seong-Je

    2017-12-01

    Stirling type pulse tube cryocoolers are very attractive for cooling of diverse application because it has it has several inherent advantages such as no moving part in the cold end, low manufacturing cost and long operation life. To develop the Stirling-type pulse tube cryocooler, we need to design a linear compressor to drive the pulse tube cryocooler. A moving magnet type linear motor of dual piston configuration is designed and fabricated, and this compressor could be operated with the electric power of 100 W and the frequency up to 60 Hz. A single stage coaxial type pulse tube cold finger aiming at over 1.5 W at 80K is built and tested with the linear compressor. Experimental investigations have been conducted to evaluate their performance characteristics with respect to several parameters such as the phase shifter, the charging pressure and the operating frequency of the linear compressor.

  4. A research of heat transfer enhancement of rectangular channel with dimples

    Directory of Open Access Journals (Sweden)

    Fu Zhe

    2017-01-01

    Full Text Available this thesis is aimed to do numerical simulations on rectangular channel with a new model of dimple in different condition of channel height, dimple depth, dimple distance by using CFD program and RNG k-ε model. It is concluded that, the existence of dimple has changed the velocity and direction of the fluid, as well as the original flow status. Dimple increased the heat exchange area of rectangular channel and broke the boundary layer, enhanced the flow rate of fluid, as a result of enhanced heat transfer performance.

  5. Enhanced lubricant film formation through micro-dimpled hard-on-hard artificial hip joint: An in-situ observation of dimple shape effects.

    Science.gov (United States)

    Choudhury, Dipankar; Rebenda, David; Sasaki, Shinya; Hekrle, Pavel; Vrbka, Martin; Zou, Min

    2018-02-17

    This study evaluates the impact of dimple shapes on lubricant film formation in artificial hip joints. Micro-dimples with 20-50 µm lateral size and 1 ± 0.2 µm depths were fabricated on CrCoMo hip joint femoral heads using a picosecond laser. Tribological studies were performed using a pendulum hip joint simulator to apply continuous swing flexion-extension motions. The results revealed a significantly enhanced lubricant film thickness (≥ 500 nm) with micro-dimpled prosthesis heads at equilibrium position after the lubricant film has fully developed. The average lubricant film thickness of dimpled prostheses with square- and triangular-shaped dimple arrays over time is about 3.5 that of the non-dimpled prosthesis (204 nm). Remarkably, the prosthesis with square-shaped dimple arrays showed a very fast lubricant film formation reaching their peak values within 0.5 s of pendulum movement, followed by prosthesis with triangular-shaped dimple arrays with a transition period of 42.4 s. The fully developed lubricant film thicknesses (≥ 700 nm) are significantly higher than the surface roughness (≈ 25 nm) demonstrating a hydrodynamic lubrication. Hardly any scratches appeared on the post-experimental prosthesis with square-shaped dimple array and only a few scratches were found on the post-experimental prosthesis with triangular-shaped dimple arrays. Thus, prostheses with square-shaped dimple arrays could be a potential solution for durable artificial hip joints. Copyright © 2018 Elsevier Ltd. All rights reserved.

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

    CERN Document Server

    Gromov, V

    2001-01-01

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

  7. Type I collagen from bullfrog ( Rana catesbeiana ) fallopian tube ...

    African Journals Online (AJOL)

    Rana catesbeiana) with a yield of 16.4%, on a dry weight basis. Sodium dodecyl sulphate polyacylamide-gel electrophoresis (SDS-PAGE) showed that the PSC contained two alpha components (α1 and α2) and was classified as type I collagen ...

  8. Analysis of heat transfer in a heated tube with a different typed disc insertion

    OpenAIRE

    Turan Betül; Öztop Hakan F.

    2012-01-01

    Heat transfer and fluid flow can be controlled in a tube by inserting different typed passive elements. The main objective of this study is to control heat transfer and fluid flow using cutting edged disc in pipe. Governing equations of laminar, two-dimensional flow is solved via finite volume technique. The disc is adiabatic and its thickness is 5mm. It is located into axial axis of the tube. Three cases were applied based on the type of the disc as inclination angle of the top side is...

  9. Spine ultrasounds should not be routinely performed for patients with simple sacral dimples.

    Science.gov (United States)

    Albert, Gregory W

    2016-08-01

    Primary care providers commonly obtain spine ultrasounds for neonates with simple sacral dimples due to perceived concerns about underlying spinal dysraphism, despite a lack of scientific evidence. Nine papers addressing routine spine ultrasounds for children with sacral dimples showed that 3.4% of the 5166 patients had abnormal spine ultrasounds, compared with the 4.8% reported by another study for children without sacral dimples. Most of the abnormal findings in patients with sacral dimples were of no clinical significance. Sacral dimples do not predict underlying spinal cord malformations, and spine ultrasounds should not be performed for neonates with simple sacral dimples. ©2016 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  10. Flux tubes and the type-I/type-II transition in a superconductor coupled to a superfluid

    International Nuclear Information System (INIS)

    Alford, Mark G.; Good, Gerald

    2008-01-01

    We analyze magnetic-flux tubes at zero temperature in a superconductor that is coupled to a superfluid via both density and gradient ('entrainment') interactions. The example we have in mind is high-density nuclear matter, which is a proton superconductor and a neutron superfluid, but our treatment is general and simple, modeling the interactions as a Ginzburg-Landau effective theory with four-fermion couplings, including only s-wave pairing. We numerically solve the field equations for flux tubes with an arbitrary number of flux quanta and compare their energies. This allows us to map the type-I/type-II transition in the superconductor, which occurs at the conventional κ≡λ/ξ=1/√(2) if the condensates are uncoupled. We find that a density coupling between the condensates raises the critical κ and, for a sufficiently high neutron density, resolves the type-I/type-II transition line into an infinite number of bands corresponding to 'type-II(n)' phases, in which n, the number of quanta in the favored flux tube, steps from 1 to infinity. For lower neutron density, the coupling creates spinodal regions around the type-I/type-II boundary, in which metastable flux configurations are possible. We find that a gradient coupling between the condensates lowers the critical κ and creates spinodal regions. These exotic phenomena may not occur in nuclear matter, which is thought to be deep in the type-II region but might be observed in condensed-matter systems

  11. Type I fitting of copper tubes from a water distribution system

    CSIR Research Space (South Africa)

    Fernandes, PJL

    1998-03-01

    Full Text Available to pitting whilst in service were subjected to a detailed failure investigation. Analysis of the tubes showed that failure was a result of Type I pitting attack. While the exact cause of pitting was unknown, it was hypothesized that it could have been due...

  12. Inspection qualification as a tool to risk based ET ISI of VVER type SG tubes

    International Nuclear Information System (INIS)

    Horacek, L.

    2002-01-01

    A Pilot study on Eddy current inspection qualification of VVER 440 steam generator tubes, discussed in this paper, followed the ENIQ methodology principles and covered briefly the assumed scope of ET qualification, relevant elaborated qualification documents, known ISI limitations and a review of input information on component and defects determined for Eddy current inspection qualification of VVER 440 steam generator tubes. The information includes the fabrication of the test blocks with SG tube segments provided by intended defect simulations of realistic SCC type and basic data on the realistic SCC type defects manufacturing technology. Lessons learned from the development of manufacturing technology of SSC type of defects, regional blind tests, elaboration of the preliminary technical justification for Eddy current automated inspections, potential optimisation of inspection procedures, laboratory and practical open trials are summarised in the paper. The results of the Pilot study also especially in relation to POD curve being determined seem to be useful for practical operational ISI programme and Risk informed ISI decisions and the establishment of plugging criteria of VVER 440 and VVER 1000 type steam generator tubes. (orig.)

  13. A comparison of three types of pulse tube refrigerators: new methods for reaching 60K

    International Nuclear Information System (INIS)

    Radebaugh, R; Louie, B.; Smith, D.R.; Zimmermann, J.

    1986-01-01

    Pulse tube or thermoacoustic refrigerators require only one moving part--an oscillating piston or diaphragm at room temperature. Refrigeration occurs within a tube connected to the pressure wave generator when the thermal relaxation time between gas and tube is comparable to a half period. Three types have been discussed in the literature recently by Gifford, by Mikulin, and by Wheatley. A record low temperature of 60 K was achieved in our work using a single stage pulse tube similar to that of Mikulin. Previously 105 K was the lowest temperature achieved. Because of only one moving part, all three types have the potential for long life, but their efficiency and intrinsic limitations have never been investigated. This paper compares the three types with each other and with common refrigerators such as Joule-Thomson and Stirling refrigerators. An apparatus is described which can measure the intrinsic behavior of the different types from temperatures of about 30 K to 300 K. Overall cycle efficiency as well as sources of loss such as conduction and regenerator ineffectiveness are discussed and the advantages of various phase shifting techniques to increase refrigeration capacity are compared

  14. A conical-type X-ray guide tube for diffraction experiments with small crystals

    International Nuclear Information System (INIS)

    Nozaki, Hiroshi; Nakazawa, Hiromoto

    1986-01-01

    The divergence and intensity distribution of X-rays transported through a conical-type X-ray guide tube (XGT) were measured. Diverging X-rays from a point source were condensed by use of the conical-type XGT. The parallelism of X-rays through the XGT was better than that encountered for a cylindrical-type XGT proposed previously. The intensity of the X-ray beam around the central axis of the conical-type XGT was exceedingly high in comparison with that measured without the tube and almost uniform over a cross-sectional area 60 μm in diameter. The high intensity provides the possibility of performing diffraction experiments with crystals as small as 20 μm in diameter with a conventional X-ray diffraction system. (orig.)

  15. Analysis of heat transfer in a heated tube with a different typed disc insertion

    Directory of Open Access Journals (Sweden)

    Turan Betül

    2012-01-01

    Full Text Available Heat transfer and fluid flow can be controlled in a tube by inserting different typed passive elements. The main objective of this study is to control heat transfer and fluid flow using cutting edged disc in pipe. Governing equations of laminar, two-dimensional flow is solved via finite volume technique. The disc is adiabatic and its thickness is 5mm. It is located into axial axis of the tube. Three cases were applied based on the type of the disc as inclination angle of the top side is 45º and 0º. Calculations were performed for different Reynolds number in the range of 335 < Re < 845. Three cases were tested based on types of discs. It is observed that each position exhibits different heat transfer ratio according to studied Reynolds number. The highest heat transfer is formed when inlet flow impinges to flat side of the cutting edged baffle.

  16. Numerical study of a VM type multi-bypass pulse tube cryocooler operating at 4K

    Science.gov (United States)

    Pan, Changzhao; Zhang, Tong; Wang, Jue; Chen, Liubiao; Cui, Chen; Wang, Junjie; Zhou, Yuan

    2017-12-01

    VM cryocooler is one kind of Stirling type cryocooler working at low frequency. At present, we have obtained the liquid helium temperature by using a two-stage VM/pulse tube hybrid cryocooler. As a new kind of 4K cryocooler, there are many aspects need to be studied and optimized in detail. In order to reducing the vibration and improving the stability of this cryocooler, a pulse tube cryocooler was designed to get rid of the displacer in the first stage. This paper presents a detail numerical investigation on this pulse tube cryocooler by using the SAGE software. The low temperature phase shifters were adopted in this cryocooler, which were low temperature gas reservoir, low temperature double-inlet and multi-bypass. After optimizing, the structure parameters and the best diameters of orifice, multi-bypass and double-inlet were obtained. With the pressure ratio of about 1.6 and operating frequency 2Hz, this cryocooler could supply above 40mW cooling power at 4.2K, and the total input power needs no more than 60W at 77K. Based on the highest efficiency of 77K high capacity cryocooler, the overall efficiency of this VM type pulse tube cryocooler is above 0.5% relative Carnot efficient.

  17. Nanoscale Dimples for Improved Absorption in and Efficiency of Organic Solar Cells

    DEFF Research Database (Denmark)

    Goszczak, Arkadiusz Jaroslaw; Adam, Jost; Cielecki, Pawel Piotr

    are compared to FDTD calculations to further explain the mechanisms of light-trapping in these structures. The nanoscale dimples as light-trapping nanostructure are integrated into inverted P3HT/PCBM organic solar cell devices. The impact from the different dimple structures on the resulting power conversion...

  18. Three-dimensional topographies of water surface dimples formed by superhydrophobic water strider legs

    Science.gov (United States)

    Yin, W.; Zheng, Y. L.; Lu, H. Y.; Zhang, X. J.; Tian, Y.

    2016-10-01

    A water strider has a remarkable capability to stand and walk freely on water. Supporting forces of a water strider and a bionic robot have been calculated from the side view of pressed depth of legs to reconstruct the water surface dimples. However, in situ measurements of the multiple leg forces and significantly small leg/water contact dimples have not been realized yet. In this study, a shadow method was proposed to reconstruct the in situ three-dimensional topographies of leg/water contact dimples and their corresponding supporting forces. Results indicated that the supporting forces were affected by the depth, width, and length of the dimple, and that the maximum dimple depth was not proportional to the supporting forces. The shadow method also has advantages in disclosing tiny supporting force of legs in their subtle actions. These results are helpful for understanding the locomotion principles of water-walking insects and the design of biomimetic aquatic devices.

  19. Recent development status of stirling type pulse tube cryocooler for HTS

    International Nuclear Information System (INIS)

    Hiratsuka, Y; Nakano, K; Kato, T

    2014-01-01

    Sumitomo Heavy Industries, Ltd. (SHI) has been developing a high power stirling type pulse tube cryocooler. For the purpose of cooling high-temperature superconductor (HTS) devices, such as superconductor motor, SMES and current fault limiter, requested specifications from the devices to a cryocooler are compact size, light weight, high efficiency and high reliability. Especially, the cryocooler must be demanded COP > 0.1 in the efficiency. The experimental results of prototype pulse tube cryocooler were reported in June 2012 [1]. For an In-line type expander, the cooling capacity was 210 W at 77 K and the minimum temperature was 37 K when the compressor input power was 3.8 kW and the operating frequency was 49 Hz. Accordingly, COP was about 0.055. Moreover, for miniaturization a U type expander was tested and the performance is about 10 % less than that of an In-line type expander. After that, we have estimated that the cooling performance is influenced by the environment such as the effect of the pulse-tube inclination, the temperature and the flowing quantity of cooling water. The detailed results are reported in this paper.

  20. Surgical outcomes of membrane-tube-type glaucoma shunt device in indigenous West Africans

    OpenAIRE

    Olawoye, Olusola; Sarimiye, Tarela; Ashaye, Adeyinka; Hwang, Young Hoon; Han, Jong Chul; Ahn, Byung Heon

    2018-01-01

    Purpose The aim of this study was to report the safety and efficacy of the membrane-tube (MT)-type glaucoma shunt device (Finetube MT) in the management of refractory glaucoma in indigenous West Africans. Methods The Finetube MT was implanted into 25 eyes of 25 West African patients with refractory glaucoma. These patients had inadequate intraocular pressure (IOP) control despite maximum tolerable IOP-lowering medications with or without previous ocular surgeries. IOP, postoperative complicat...

  1. Boreside rotating ultrasonic tester for wastage determination of LMFBR-type steam generator tubes

    International Nuclear Information System (INIS)

    Neely, H.H.; Renger, H.L.

    1979-01-01

    Large sodium-water reaction (SWR) leak tests are being run in near-prototypic steam generators at prototypic plant conditions of the Liquid Metal Fast Breeder Reactor (LMFBR). These tests simulate various types of steam tube failure at predetermined locations. A SWR results in a highly energetic-exothermic-caustic reaction which erodes neighboring tubes. A boreside-rotating ultrasonic inspection device was developed to measure wall thickness and inside diameter of the 2/one quarter/Cr-1 Mo, 10.1 mm I.D. steam tubes. Rotation of the UT beam yields a complimentary scan of the full tube in a single pass. The UT system was designed with a 15 MHz transducer in pulse-echo compression-wave mode at a pulse rate of 10,000/second. The UT beam is rotated at 20 r/s on a 1.27 mm pitch. System outputs are diameter, wall thickness, attitude, and axial position. Measurements are processed, then fed to a CRT and computer for later retrieval and plotting

  2. Investigation of passive residual heat removal system for VVERs: Effects of finned type heat exchanger tubes

    International Nuclear Information System (INIS)

    Ayhan, Hüseyin; Sökmen, Cemal Niyazi

    2016-01-01

    Highlights: • Performance of passive residual heat removal system (PRHRS) of VVER type nuclear power plants is investigated. • Unit heat exchanger of PRHRS is designed to reject 4 MW heat amount from reactor via steam generator. • This study shows that decay heat can be rejected by 16 heat exchangers of PRHRS without any operator actions. - Abstract: After nuclear reactor shutdown, decay heat generation continues in the reactor core and it has the possibility to cause a severe accident. This residual heat has to be removed from the core sufficiently. In Water-Water Energetic Reactors (WWER) or VVERs, passive residual heat removal system is designed to remove decay heat after reactor shutdown. This system does not need any power operation, since ambient air is used as the cooling fluid in heat exchanger. The steam that is generated in the steam generators due to the heat released in the reactor core condenses and rejects its heat to the ambient air within this heat exchanger. The condensed liquid is returned back to the steam generator. The motion of the cooling medium occurs due to natural circulation. In the presented study, the original geometric design of passive residual heat removal system of VVER type nuclear power plants is introduced. The performance of this system is investigated. In the previous study, geometric design parameters for this system was determined for plain tubes of heat exchanger. Heat exchanger tubes were positioned as a helical in the previous study. With the knowledge of enhancing heat transfer using finned surfaces, geometrical design is modified in presented study. Circular type fin structures (having rectangular cross-section) are added to the outer surface of heat exchanger tubes. In the present heat exchanger model, tubes are positioned as a staggered bank. As the fin parameters, fin thickness, fin radius and total fin number are investigated in this study. Results are compared with the one obtained with plane tube (in tube

  3. Numerical simulation of dimples in airfoil using MATLAB

    Science.gov (United States)

    Booma Devi, P.; Shah, Dilip A.

    2017-05-01

    The Aircraft wing is a point of important research which poses greater challenge in terms of aerodynamic efficiency. The flow separation control method is addressed in classical aerodynamics methods. This study focuses on influence of dimples on controlling the flow and also increasing the aerodynamic efficiency. The periodic process of placing the cavities on the wing starting from root to tip controls the flow separation. The linear variation of characteristic curve provides the information about the flow separation and control of flow on upper surface of the airfoil.These different shapes are utilized viz., Square, Rectangle and Triangle. The numerical simulation is carried out in using MATLAB package. Preliminary analysis on the flow separation is carried out focuses on laminar flow separation, which has the influence on the overall lift generation and drag generation.

  4. Surface dimpling on rotating work piece using rotation cutting tool

    Science.gov (United States)

    Bhapkar, Rohit Arun; Larsen, Eric Richard

    2015-03-31

    A combined method of machining and applying a surface texture to a work piece and a tool assembly that is capable of machining and applying a surface texture to a work piece are disclosed. The disclosed method includes machining portions of an outer or inner surface of a work piece. The method also includes rotating the work piece in front of a rotating cutting tool and engaging the outer surface of the work piece with the rotating cutting tool to cut dimples in the outer surface of the work piece. The disclosed tool assembly includes a rotating cutting tool coupled to an end of a rotational machining device, such as a lathe. The same tool assembly can be used to both machine the work piece and apply a surface texture to the work piece without unloading the work piece from the tool assembly.

  5. Creep and creep rupture properties of cladding tube (type 316) in high temperature sodium

    International Nuclear Information System (INIS)

    Atsumo, H.

    1977-01-01

    The thin walled small sized seamless AISI 316 steel tubes, which are designated to be domestically used as the fuel cladding tube for sodium cooled fast breeder reactors in Japan, are irradiated in the following sodium of high temperature in the range of 370 deg. C to 700 deg. C, and receive gradually increased internal pressure caused by the fission produced gas generating from the nuclear fuel burn-up inside the cladding tube. Consequently, the creep behavior of fuel cladding tubes under a high temperature sodium environment is an important problem which must be determined and clarified together with their characteristic features under irradiation and in air. In relation to the creep performance of fuel cladding tubes made of AISI 316 steel and other comparable austenitic stainless steels, hardly any studies are found that are made systematically to examine the effect of sodium with sodium purity as parameter or any comparative studies with in-air data at various different temperatures. The present research work was aimed to obtain certain basic design data relating to in-sodium creep performance of the domestic made fuel cladding tubes for fast breeder reactors, and also to gain further date as considered necessary under several sodium conditions. That is, together with establishment of the technology for tensile creep test and internal pressure creep rupture test in flowing sodium of high temperature, a series of tests and studies were performed on the trial made cladding tubes of AISI Type-316 steel. In the first place, two kinds of purity conditions of sodium, close to the actual reactor-operating condition, (oxygen concentration of 10 ppm and 5 ppm respectively) were established, and then uniaxial tensile creep test and rupture test under various temperatures were performed and the resulting data were compared and evaluated against the in-air data. Then, secondly, an internal pressure creep rupture test was conducted under a single purity sodium environment

  6. Closed loop control of a cylindrical tube type Ionic Polymer Metal Composite (IPMC)

    Science.gov (United States)

    Mead, Benjamin T.

    The goal of this research is to provide a framework for the integration of tube type, cylindrical Ionic Polymer Metal-Composite (IPMC) into conventional devices. IPMCs are one of the most widely used types of electro-active polymer actuator, due to their low electric driving potential and large deformation range. For this research a tube type IPMC was investigated. This IPMC has a circular cross section with four separate electrodes on its surface and a hole through the middle. The four electrodes allow for biaxial bending and accurate control of the tip location. One of the main advantages of using this type of IPMC is the ability to embed a specific tool and accurately control the tool tip location using the large deflection range of the IPMC. This ability has widespread applications including in the biomedical field for use in active catheter procedures. First, this relatively new type of IPMC is investigated and characterized. The processes and materials used are described and the functional design is explored. Before the modeling process beings the basic functions of the IPMC are investigated. To this end force and displacement experiments are performed to describe the activation of the tube type IPMC. This data will be used later to verify and calibrate the mathematical simulations. Second, a three dimensional multi-physics finite element model is developed using COMSOL 4.3a. This model will automatically couple three physics packages and provide a description of the fluid interactions within the tube type IPMC. This model is then compared against the experimental displacement results to calibrate the simulation. Using this simulation design parameters are declared including, overall diameter, and tool hole size. The performance of the IPMC is then simulated while varying these parameters. Third, an electro-mechanical model of the IPMC is developed. This macroscopic model is used to relate the input voltage to an associated tip deflection. Several model types

  7. Evaluation of compression-type tube fittings for use at INEL

    International Nuclear Information System (INIS)

    McBride, J.

    1979-08-01

    INEL has been using mostly Swagelok compression-type tube fittings for more than 20 years. Suppliers of other similar lines of tube fittings have complained that fittings for warehouse stores should be purchased on a competitive bid basis. Previous studies on this subject have recommended the continued use of Swagelok on a sole-source basis. This policy has been maintained, but not formally stated to suppliers. Continuous marketing pressure from Gyrolok and Parker-Hannifin has resulted in a decision by the EG and G Idaho, Inc., Materiel Division and DOE-ID personnel to formulate a uniform policy on the warehousing of compression-type tube fittings. This report was prepared to give the EG and G Idaho, Inc., Materiel Division and DOE-ID management the best available information necessary to make a rational decision. It is concluded that the Swagelok fitting is the best available product of the three evaluated from the standpoints of technical adequacy and overall cost to the Government. It is recommended that INEL warehouse only the Swagelok brand

  8. Evaluation of cooling performance of impinging jet array over various dimpled surfaces

    Science.gov (United States)

    Kim, Sun-Min; Kim, Kwang-Yong

    2016-04-01

    Various configurations of an impinging jet-dimple array cooling system were evaluated in terms of their heat transfer and pressure drop performances. The steady incompressible laminar flow and heat transfer in the cooling system were analyzed using three-dimensional Navier-Stokes equations. The obtained numerical results were validated by a comparison with experimental data for the local Nusselt number distribution. The area-averaged Nusselt number on the projected area and the pressure drop through the system were selected as the performance parameters. Among the four tested configurations—inline concave, staggered concave, inline convex, and staggered convex—the staggered convex impinging jet-dimple array showed the best heat transfer performance whereas the staggered-concave configuration showed the lowest pressure drop. A parametric study with two geometric variables, i.e., the height of dimple and the diameter of dimple, was also conducted for the staggered-convex impinging jet-dimple array. As a result, the best heat transfer and pressure drop performances were achieved when the ratio of the height of dimple to the diameter of jet was 0.8. And, the increase in the ratio of the diameter of dimple to the diameter of jet yielded monotonous increase in the heat transfer performance.

  9. Heat transfer under transition and film boiling of liquids at dimpled spheres and cylinders

    Science.gov (United States)

    Zhukov, V. M.; Kuzma-Kichta, Yu. A.; Lavrikov, A. V.; Belov, K. I.; Len’kov, V. A.

    2018-03-01

    The article presents the results of studies of heat transfer and film and transition boiling mechanism of nitrogen, Refrigerant R-113, and water at spheres and vertical cylinders, which surfaces are covered with spherical dimples.. The data were obtained under the conditions of pool boiling and natural circulation in vertical 1.0 and 2.5 mm wide annular channels. Hemispherical dimples of 3 mm diameter (h/d = 0.17) were made on sample surfaces. The dimples occupied 45% of the sphere surface and 37% of the cylinder surface. In some tests, the dimpled surface was additionally covered with low-conductive coating (10 µm film). Minimal cooling time for the sphere with dimples and low-conductive coating took place under natural circulation in 2.5 mm annular gap and it was almost 2.5 times lower than that for a smooth sphere under pool boiling. It is shown that at pool boiling the presence of dimples and low-conductive coating leads to heat transfer enhancement at transition and film boiling regimes, while at natural circulation such an enhancement occurs at film boiling with high temperature differences. The tests at natural circulation in vertical annular channels of different width showed that in this case an intensity of boiling heat transfer is higher than that at pool boiling. High-speed filming of film boiling process on the surfaces with dimples was conducted.

  10. High efficiency 40 K single-stage Stirling-type pulse tube cryocooler

    Science.gov (United States)

    Wu, X. L.; Chen, L. B.; Pan, C. Z.; Cui, C.; Wang, J. J.; Zhou, Y.

    2017-12-01

    A high efficiency single-stage Stirling-type coaxial pulse tube cryocooler (SPTC) operating at around 40 K has been designed, built and tested. The double-inlet and the inertance tubes together with the gas reservoir were adopted as the phase shifters. Under the conditions of 2.5 MPa charging pressure and 30 Hz operating frequency, the prototype has achieved a no-load temperature of 23.8 K with 330 W of electric input power at a rejection temperature of 279 K. When the input power increases to 400 W, it can achieve a cooling capacity of 4.7 W/40 K while rejecting heat at 279 K yielding an efficiency of 7.02% relative to Carnot. It achieves a cooling capacity of 5 W/40 K with an input power of 450 W. It takes 10 minutes for the SPTC to cool to its no-load temperature of 40 K from 295 K.

  11. Acoustic emission characteristics of stress corrosion cracks in a type 304 stainless steel tube

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Woong Gi; Bae, Seung Gi; Lee, Bo Young [School of Aerospace and Mechanical Engineering, Korea Aerospace University, Goyang (Korea, Republic of); Kim, Jae Seong [Center for Robot Technology and Manufacturing, Institute for Advanced Engineering, Yongin (Korea, Republic of); Kang, Sung Sik [Dept. of Nuclear Safety Research, Daejeon (Korea, Republic of); Kwag, Nog Won [Ultrasonic Division, RM910, Byucksan Digital Valley II, Seoul (Korea, Republic of)

    2015-06-15

    Acoustic emission (AE) is one of the promising methods for detecting the formation of stress corrosion cracks (SCCs) in laboratory tests. This method has the advantage of online inspection. Some studies have been conducted to investigate the characteristics of AE parameters during SCC propagation. However, it is difficult to classify the distinct features of SCC behavior. Because the previous studies were performed on slow strain rate test or compact tension specimens, it is difficult to make certain correlations between AE signals and actual SCC behavior in real tube-type specimens. In this study, the specimen was a AISI 304 stainless steel tube widely applied in the nuclear industry, and an accelerated test was conducted at high temperature and pressure with a corrosive environmental condition. The study result indicated that intense AE signals were mainly detected in the elastic deformation region, and a good correlation was observed between AE activity and crack growth. By contrast, the behavior of accumulated counts was divided into four regions. According to the waveform analysis, a specific waveform pattern was observed during SCC development. It is suggested that AE can be used to detect and monitor SCC initiation and propagation in actual tubes.

  12. Acoustic emission characteristics of stress corrosion cracks in a type 304 stainless steel tube

    Directory of Open Access Journals (Sweden)

    Woonggi Hwang

    2015-06-01

    Full Text Available Acoustic emission (AE is one of the promising methods for detecting the formation of stress corrosion cracks (SCCs in laboratory tests. This method has the advantage of online inspection. Some studies have been conducted to investigate the characteristics of AE parameters during SCC propagation. However, it is difficult to classify the distinct features of SCC behavior. Because the previous studies were performed on slow strain rate test or compact tension specimens, it is difficult to make certain correlations between AE signals and actual SCC behavior in real tube-type specimens. In this study, the specimen was a AISI 304 stainless steel tube widely applied in the nuclear industry, and an accelerated test was conducted at high temperature and pressure with a corrosive environmental condition. The study result indicated that intense AE signals were mainly detected in the elastic deformation region, and a good correlation was observed between AE activity and crack growth. By contrast, the behavior of accumulated counts was divided into four regions. According to the waveform analysis, a specific waveform pattern was observed during SCC development. It is suggested that AE can be used to detect and monitor SCC initiation and propagation in actual tubes.

  13. A cryogen-free Vuilleumier type pulse tube cryocooler operating below 10 K

    Science.gov (United States)

    Wang, Yanan; Wang, Xiaotao; Dai, Wei; Luo, Ercang

    2018-03-01

    Vuilleumier (VM) type pulse tube cryocooler (PTC) utilizes the thermal compressor to drive the low temperature stage PTC. This paper presents the latest experimental results of a cryogen-free VM type PTC that operates in the temperature range below 10 K. Stirling type pre-coolers instead of liquid nitrogen provide the cooling power for the thermal compressor. Compared with previous configuration, the thermal compressor was improved with a higher output pressure ratio, and lead and HoCu2 spheres were packed within the regenerator for the low temperature stage PTC for a better match with targeted cold end temperature. A lowest no-load temperature of 7.58 K was obtained with a pressure ratio of 1.23, a working frequency of 3 Hz and an average pressure of 1.63 MPa. The experimental results show good consistency in terms of lowest temperature with the simulation under the same working condition.

  14. Study of Dimple Effect on the Friction Characteristics of a Journal Bearing using Taguchi Method

    Science.gov (United States)

    Murthy, A. Amar; Raghunandana, Dr.

    2018-02-01

    The effect of producing dimples using chemically etched techniques or by machining process on the surface of a journal bearing bushing to reduce the friction using Taguchi method is investigated. The data used in the present analysis is based on the results obtained by the series of experiments conducted to study the dimples effect on the Stribeck curve. It is statistically proved that producing dimples on the bushing surface of a journal bearing has significant effect on the friction coefficient when used with light oils. Also it is seen that there is an interaction effect between speeds-load and load-dimples. Hence the interaction effect, which are usually neglected should be considered during actual experiments that significantly contributes in reducing the friction in mixed lubrication regime. The experiments, if were conducted after Taguchi method, then the number of experiments would have been reduced to half of the actual set of experiments that were essentially conducted.

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

    International Nuclear Information System (INIS)

    Darsono; Suhartono; Suprapto; Elin Nuraini

    2015-01-01

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

  16. Design and Fabrication of Serpentine Tube Type Sodium to Air Heat Exchangers for PFBR SGDHR Circuits

    International Nuclear Information System (INIS)

    Pai, Aravinda; Mitra, Tarun Kumar; Loganathan, T.; Kumar, Prabhat

    2015-01-01

    Prototype Fast Breeder Reactor (PFBR) is a 500MWe pool type, sodium cooled nuclear reactor which is in advanced stage of construction by BHAVINI at Kalpakkam, India. The sodium to air heat exchanger (AHX) in the safety grade decay heat removal (SGDHR) loop transfers heat from the intermediate circuit sodium to atmospheric air by natural convection. As the operating temperature is high and AHX forms part of reactor SGDHR system, the boundaries of the AHX must possess a high degree of reliability against failure. This is achieved by comprehensive design, precise material selection, high standard quality control and quality assurance during manufacturing. The major material of construction of AHX is Modified 9Cr-1Mo steel (N&T). AHX has straight sodium inlet and outlet headers with 116 nos. of hot formed pullouts on its surface having OD38.1mmX2.6mm thickness which are connected to a finned tube bundle. Due to the many hot formed pullouts on the headers and complex geometry, the welding sequence, heat treatment and non-destructive examinations of the welds is an extremely difficult and challenging task. Various special tooling and fixtures were designed and developed for the manufacture of the AHXs. This paper provides details of the salient design aspects, challenges, innovations and success achieved during hot forming, welding and fabrication activities of the serpentine tube type AHXs for 500MWe Prototype Fast Breeder Reactor. (author)

  17. Neural tube defects in Waardenburg syndrome: A case report and review of the literature.

    Science.gov (United States)

    Hart, Joseph; Miriyala, Kalpana

    2017-09-01

    Waardenburg syndrome type 1 (WS1) is an autosomal dominant genetic condition characterized by sensorineural deafness and pigment abnormalities, and is caused by variants in the PAX3 homeodomain. PAX3 variants have been associated with severe neural tube defects in mice and humans, but the frequency and clinical manifestations of this symptom remain largely unexplored in humans. Consequently, the role of PAX3 in human neural tube formation remains a study of interest, for clinical as well as research purposes. Though the association between spina bifida and WS1 is now well-documented, no study has attempted to characterize the range of spina bifida phenotypes seen in WS. Spina bifida encompasses several diagnoses with a wide scope of clinical severity, ranging from spina bifida occulta to myelomeningocele. We present a patient with Waardenburg syndrome type 1 caused by a novel missense variant in PAX3, presenting with myelomeningocele, Arnold-Chiari malformation, and hydrocephalus at birth. Additionally, we review 32 total cases of neural tube defects associated with WS. Including this report, there have been 15 published cases of myelomeningocele, 10 cases of unspecified spina bifida, 3 cases of sacral dimples, 0 cases of meningocele, and 4 cases of miscellaneous other neural tube defects. Though the true frequency of each phenotype cannot be determined from this collection of cases, these results demonstrate that Waardenburg syndrome type 1 carries a notable risk of severe neural tube defects, which has implications in prenatal and genetic counseling. © 2017 Wiley Periodicals, Inc.

  18. The Optimum Selection and Drawing Output Program Development of Shell and Tube Type Oil Cooler

    International Nuclear Information System (INIS)

    Lee, Y. B.; Kim, T. S.; Ko, J. M

    2007-01-01

    Shell and Tube type Oil Cooler is widely used for hydraulic presses, die casting machines, generation equipments, machine tools and construction heavy machinery. Temperature of oil in the hydraulic system changes viscosity and thickness of oil film. They have a bad effect to performance and lubrication of hydraulic machinery, so it is important to know exactly the heat exchanging efficiency of oil cooler for controlling oil temperature. But most Korean manufacturers do not have test equipment for oil cooler, so they cannot carry out the efficiency test of oil cooler and it is impossible to verify its performance. This paper includes information of construction of necessary utilities for oil cooler test and design and manufacture of test equipment. One can select the optimum product by obtaining performance data through tests of various kinds of oil coolers. And also the paper developed a program which can be easily used for design of 2D and 3D drawings of oil cooler

  19. Loss Analysis of High Power Stirling-Type Pulse Tube Cryocooler

    International Nuclear Information System (INIS)

    Nakano, K; Hiratsuka, Y

    2015-01-01

    For the purpose of cooling high-temperature superconductor (HTS) devices, such as superconductor motors, superconducting magnetic energy storage (SMES) and current fault limiters, cryocoolers should be compact in size, light-weight, and have high efficiency and reliability. In order to meet the demand of HTS devices world-wide, the cryocooler needs to have COP efficiency >0.1. We have developed a high power Stirling-type pulse tube cryocooler (SPTC) with an in-line expander. The experimental results were reported in June 2012[1]. The cooling capacity was 210 W at 77 K and the minimum temperature was 37 K when the compressor input power was 3.8 kW. Accordingly, the COP was about 0.055. To further improve the efficiency, the energy losses in the cryocooler were analyzed. The experimental results and the numerical calculation results are reported in this paper. (paper)

  20. The in-vitro response of pollen germination and tube length to different types of acidity.

    Science.gov (United States)

    Paoletti, E; Bellani, L M

    1990-01-01

    Pollen germination and tube growth are among the most sensitive responses to atmospheric pollution. Both these are inhibited by the acidity of the growth medium. Pollen grains from two species (Pinus cembra L. and Sambucus nigra L.) were germinated in media over a range of pHs (5.0, 4.5, 4.0, 3.5, 3.0 and 2.5) and six types of acidity (H(2)SO(4), HNO(3), H(2)SO(4): HNO(3) in 1:1, 2:1, 3:1 and 5:1 ratio). Pollen of the Gymnosperm is shown to be more resistant to acidity in the medium. Sulphuric acid alone and the ratio 2:1 with nitric acid are demonstrated to be the more harmful for P. cembra and S. nigra, respectively. The latter species was sensitive to all mixtures, particularly in respect to germination percentage.

  1. Structural Pre-sizing of a Coaxial Double-tube Type Hot Gas Duct

    Energy Technology Data Exchange (ETDEWEB)

    Song, Kee Nam; Kim, Y-W [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2008-10-15

    The nuclear hydrogen system being researched at KAERI is planning to produce hydrogen in the order of 950 .deg. C by using nuclear energy and a thermo-chemical process, and helium gas is tentatively considered as the choice for the coolant. A hot gas duct (HGD) is a key component connecting the reactor pressure vessel and the intermediate heat exchanger (IHX) for the nuclear hydrogen system. The HGD is a unique component exclusively found in an HTR-module concept where a nuclear core and IHX are placed separately into two pressure vessels, which require a connecting duct between them. A coaxial double-tube type cross vessel is considered for the HGD structure of the nuclear hydrogen system because of its successive extensive experience. In this study, a structural pre-sizing for the primary HGD was carried out. These activities include a predecision on the geometric dimensions, a pre-evaluation on the strength, and a pre-selection on the material of the coaxial double-tube type cross vessel components. A predecision on the geometric dimensions was undertaken based on various engineering concepts, such as a constant flow velocity (CFV) model, a constant flow rate (CFR) model, a constant hydraulic head (CHH) model, and finally a heat balanced (HB) model. For the CFV model, CFR model, and CHH model, the HGD structure might be insensitive to a flow induced vibration (FIV) in the case where there are no pressure differences between the hot and cold helium regions. Also we compared the geometric dimensions from the various models.

  2. DEVELOPMENT OF A 4 K STIRLING-TYPE PULSE TUBE CRYOCOOLER FOR A MOBILE TERAHERTZ DETECTION SYSTEM

    International Nuclear Information System (INIS)

    Bradley, P. E.; Gerecht, E.; Radebaugh, R.; Garaway, I.

    2010-01-01

    We discuss in this paper the design and development of a 4 K Stirling-type pulse tube cryocooler for a mobile terahertz detection system. This system integrates new heterodyne detector technology at terahertz frequencies with advancements of Stirling-type pulse tube technology that brings the advent of cooled detector sensitivities in a mobile, compact, and long duration operation system without degradation of sensitivity. To achieve this goal we reduced overall system size, input power, and temperature fluctuations and mechanical vibrations in order to maintain the detector sensitivity. The Stirling-type pulse tube cryocooler developed for this system is a hybrid design employing a He-4 pulse-tube cryocooler operating at 60 Hz and 2.5 MPa average pressure that precools a He-3 pulse tube cryocooler operating at 30 Hz and 1.0 MPa average pressure to achieve 4 K cooling for the terahertz receiver. The He-4 cryocooler employs stainless steel mesh regenerators for the first stage and ErPr spheres for the second stage, while the He-3 cryocooler employs stainless mesh for the first stage and ErPr spheres for the second stage with a layered rare-earth third stage regenerator. Design details and cooler performance goals are discussed.

  3. A novel approach for preparation of micrometer-sized, monodisperse dimple and hemispherical polystyrene particles.

    Science.gov (United States)

    Tanaka, Takuya; Komatsu, Yoshifumi; Fujibayashi, Teruhisa; Minami, Hideto; Okubo, Masayoshi

    2010-03-16

    Micrometer-sized, monodisperse dimple and hemispherical polystyrene (PS) particles were successfully prepared by heating (55-70 degrees C) of spherical PS particles dispersed in methanol/water media (40/60 to 80/20, w/w) in the presence of decane droplets, and subsequent cooling down to room temperature. Decane was absorbed by the PS particles during the heating process. Decane-absorbed PS particles phase-separated into PS and decane phases in the inside during the cooling process, and eventually dimple and/or hemispherical particles were formed by removal of the decane phase from phase-separated PS/decane particles by evaporation. The size of the dimple, which is determined by the volume of decane phase-separated from decane-absorbed PS particles during the cooling process, increased with increases in the heating temperature and the methanol content.

  4. Safety of pull-type and introducer percutaneous endoscopic gastrostomy tubes in oncology patients: a retrospective analysis

    Directory of Open Access Journals (Sweden)

    Pelckmans Paul A

    2011-03-01

    Full Text Available Abstract Background Percutaneous endoscopic gastrostomy (PEG allows long-term tube feeding. Safety of pull-type and introducer PEG placement in oncology patients with head/neck or oesophageal malignancies is unknown. Methods Retrospective analysis of 299 patients undergoing PEG tube placement between January 2006 and December 2008 revealed 57 oncology patients. All patients with head/neck or oesophageal malignancy were treated with chemo- and radiotherapy. In case of high-grade stenosis introducer Freka® Pexact PEG tube was placed (n = 24 and in all other patients (n = 33 conventional pull-type PEG tube. Short-term complications and mortality rates were compared. Results Patients' characteristics and clinical status were comparable in both groups. Short-term complications were encountered in 11/24 (48% introducer PEG patients as compared to only 4/33 (12% pull-type PEG patients (P vs. 0/33 (0%, P vs. 3/33 (9%, NS. Finally, 3/24 gastrointestinal perforations (12% resulted from a difficult placement procedure vs. 1/33 (3%, leading to urgent surgical intervention and admission to ICU. Two introducer PEG patients died at ICU, resulting in an overall mortality rate of 8% vs. 0% (P = 0.091. Conclusion The introducer Freka® Pexact PEG procedure for long-term tube feeding may lead to significantly higher complication and mortality rates in patients with head/neck or oesophageal malignancies treated with chemo- and radiotherapy. It is suggested to use the conventional pull-type PEG tube placement in this group of patients, if possible.

  5. Contact splitting and the effect of dimple depth on static friction of textured surfaces.

    Science.gov (United States)

    Greiner, Christian; Schäfer, Michael; Popp, Uwe; Gumbsch, Peter

    2014-06-11

    The morphological texturing of surfaces has demonstrated its high potential to maximize adhesion as well as to reduce friction and wear. A key to understanding such phenomena is a principle known as contact splitting. Here, we extend this concept to the static friction behavior of dimpled surfaces. Our results indicate that contact splitting does exist for such structures and that with certain dimple sizes and depths static friction values significantly exceeding those of untextured surfaces can be obtained. These results can be applied to all surfaces where friction forces are to be tuned, from nanoelectromechanical systems up to combustion engines.

  6. Measurements and comparison of focal spot sizes of two types of x-ray tubes installed in simulators

    International Nuclear Information System (INIS)

    Wen, C.; Sorell, G.; Hille, N.

    1996-01-01

    Full text: Measurements of the effective focal spot size of two types of X-ray tubes installed in radiotherapeutic simulators (TOSHIBA and VARIAN-Ximatron) are presented. As recommended in ACPSEM Quality Assurance Protocols for Diagnostic X-ray Equipment [Heggie and Petty, APESM, Vol.8 No.1 1985], the effective focal spot size of X-ray tube is vital in determining the maximum resolution of radiographic and fluoroscopic images. Hence, the quality of clinical performance of diagnostic equipment is depended to a large extent upon the accuracy in measuring and maintaining the focal spot size of the X-ray tube and regular QA program. In determining the shape and the dimension of the effective focal spot that is located within the X-ray tube and can not be measured directly, a method developed by Spiegler and Breckinridge [Spiegler and Breckinrige, Radiation Physics, Vol. 102 Mar. 1972] was used. By irradiating a lead star pattern which is placed in a divert X-ray beam between the tube and a negative film, a magnified radiographic image of the test pattern can be obtained from a standard X-ray film. The actual shape of the effective focus is determined by tracing the locus of the image intensity inversion of the radial pattern where that is occurring when only a certain condition of spatial variation from a central ray-line is met. Then, the dimension of the focal spot can be calculated. In this measurements, three different test patterns (Typ 9/1, 5 deg Vertex Angle 0.03 mm Pb, Typ 9-2 deg-360 0.05 mmPb and Typ 9 Teilung 2 deg 0.05 mm Pb) with same diameter of 45 mm are used. Results from a series measurements which were carried out repetitively under same working condition of both simulators indicate that the effective focal spots of these two tubes are of similar rectangular shape. However, the dimensions of the focal spots are about 1.297 X 0.848 mm for the TOSHIBA tube and 0.692 X 0.532 mm for the Ximatron tube. The orientation of the focal spot for TOSHIBA tube is

  7. Switching process between bistable positons of multiquantum flux tubes in a thin-film type I superconductor

    International Nuclear Information System (INIS)

    Parisi, J.; Huebener, R.P.; Muhlemeier, B.

    1983-01-01

    A superconducting memory device based on a bistable vortex position represents an interesting storage medium for future Josephson computers. In order to study the operational mode of such a single-flux quantum memory cell, we use as a model system multiquantum flux tubes in a thin-film type I superconductor (Pb). By employing high-resolution stroboscopic magnetooptical flux detection, we are able to globally visualize both spatial and temporal behavior of rapidly switching individual flux tubes. All experimental results agree reasonably well with theoretical model considerations of the energy balance during the elementary switching process

  8. The study on a gas-coupled two-stage stirling-type pulse tube cryocooler

    Science.gov (United States)

    Wu, X. L.; Chen, L. B.; Zhu, X. S.; Pan, C. Z.; Guo, J.; Wang, J. J.; Zhou, Y.

    2017-12-01

    A two-stage gas-coupled Stirling-type pulse tube cryocooler (SPTC) driven by a linear dual-opposed compressor has been designed, manufactured and tested. Both of the stages adopted coaxial structure for compactness. The effect of a cold double-inlet at the second stage on the cooling performance was investigated. The test results show that the cold double-inlet will help to achieve a lower cooling temperature, but it is not conducive to achieving a higher cooling capacity. At present, without the cold double-inlet, the second stage has achieved a no-load temperature of 11.28 K and a cooling capacity of 620 mW/20 K with an input electric power of 450 W. With the cold double-inlet, the no-load temperature is lowered to 9.4 K, but the cooling capacity is reduced to 400 mW/20 K. The structure of the developed cryocooler and the influences of charge pressure, operating frequency and hot end temperature will also be introduced in this paper.

  9. Pseudohyperkalaemia in leukaemic patients: the effect of test tube type and form of transport to the laboratory.

    Science.gov (United States)

    Dastych, Milan; Cermáková, Zdenka

    2014-01-01

    The present study was aimed at determining the effect of the tube type used for primary sample collection and the manner of transport prior to assessment (either manual or by pneumatic tube) on the degree of pseudohyperkalaemia in leukaemic patients. Blood from six leukaemic patients was collected into seven primary sample tubes (Monovette®, Sarstedt): sample A, heparinized blood gas syringe (potassium reference value); sample B, plasma Li-heparin without separator gel; sample C, plasma Li-heparin with separator gel; and sample D, serum with separator gel. The primary sample tubes designated B, C and D were transported to the laboratory manually. Duplicates of the same sample tubes, B(PT), C(PT) and D(PT), were sent to the laboratory by pneumatic tube. In patients with chronic lymphocytic leukaemia (CLL), there was no increase in the concentration of potassium in samples B, C and D when compared to the reference value. Transport of the samples by pneumatic tube led to a pronounced increase in potassium concentration in samples B(PT) and C(PT), whereas there was no increase in sample D(PT) when compared to the reference value. In the patient with chronic myeloid leukaemia (CML), an increase in potassium concentration occurred in sample D and in samples B(PT), C(PT) and D(PT). A similar finding was observed in the patient with acute lymphocytic leukaemia (ALL), furthermore with an extremely high concentration of potassium in samples C and C(PT). Manual transport of non-coagulable blood (plasma Li-heparin without separator gel) to the laboratory results in the least possible artificial increase in potassium concentration in the sample.

  10. Numerical Thermodynamic Analysis of Two-Phase Solid-Liquid Abrasive Flow Polishing in U-Type Tube

    Directory of Open Access Journals (Sweden)

    Junye Li

    2014-08-01

    Full Text Available U-type tubes are widely used in military and civilian fields and the quality of the internal surface of their channel often determines the merits and performance of a machine in which they are incorporated. Abrasive flow polishing is an effective method for improving the channel surface quality of a U-type tube. Using the results of a numerical analysis of the thermodynamic energy balance equation of a two-phase solid-liquid flow, we carried out numerical simulations of the heat transfer and surface processing characteristics of a two-phase solid-liquid abrasive flow polishing of a U-type tube. The distribution cloud of the changes in the inlet turbulent kinetic energy, turbulence intensity, turbulent viscosity, and dynamic pressure near the wall of the tube were obtained. The relationships between the temperature and the turbulent kinetic energy, between the turbulent kinetic energy and the velocity, and between the temperature and the processing velocity were also determined to develop a theoretical basis for controlling the quality of abrasive flow polishing.

  11. Study of tensile test behavior of austenitic stainless steel type 347 seamless thin-walled tubes in cold worked condition

    Energy Technology Data Exchange (ETDEWEB)

    Terui, Clarice, E-mail: clarice.terui@marinha.mil.br [Centro Tecnológico da Marinha em São Paulo (CINA/CTMSP), Iperó, SP (Brazil). Centro Industrial Nuclear da Marinha; Lima, Nelson B. de, E-mail: nblima@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNE-SP), Sao Paulo, SP (Brazil)

    2017-07-01

    These austenitic stainless steel type 347 seamless thin-walled tubes are potential candidates to be used in fuel elements of nuclear power plants (as PWR - Pressurized Water Reactor). So, their metallurgical condition and mechanical properties, as the tensile strength and yield strength, normally are very restrict in demanding project and design requirements. Several full size tensile tests at room temperature and high temperature (315 deg C) were performed in these seamless tubes in cold-worked condition. The results of specified tensile and yield strengths were achieved but the elongation of the tube, in the geometry of the component, could not be measured at high temperature due to unconventional mode of rupture (helical mode without separation of parts). The average value of elongation was obtained from stress-strain curves of hot tensile tests and was around 5%. The results obtained in this research show that this behavior of the full size tensile test samples of thin-walled tube (wall thickness less than 0.5 mm) in high temperature (315°C) is due to the combination of the manufacturing process, the material (crystallographic structure and chemical composition) and the final geometry of the component. In other words, the strong crystallographic texture of material induced by tube drawing process in addition with the geometry of the component are responsible for the behavior in hot uniaxial tensile tests. (author)

  12. Preanalytics of urine sediment examination: effect of relative centrifugal force, tube type, volume of sample and supernatant removal.

    Science.gov (United States)

    Bunjevac, Amalija; Gabaj, Nora Nikolac; Miler, Marijana; Horvat, Anita

    2018-02-15

    Laboratories often modify procedures recommended by the European Urinalysis Guidelines for urine sediment analysis. The aim of this study was to compare the recommended protocol with our routine laboratory procedure and to evaluate the possible impact of modifications in the relative centrifugal force, type of tube, method of supernatant aspiration and urine volume on patient's results. Firstly, relative centrifugal force was investigated using 20 pairs of samples examined after centrifugation at 400xg and 1358xg. In phase two, 110 samples were examined, paired as: round bottom vs conical tube (N = 46), decanting vs suction of supernatant (N = 100) and 10 mL vs 5 mL of urine sample (N = 101). The number of erythrocytes, leukocytes and squamous epithelial cells was significantly lower after centrifugation at 400xg (P = 0.001, 0.002 and 0.004, respectively). The number of leukocytes was significantly lower in conical tubes (P = 0.010), after the suction of supernatant (P = 0.045) and in 5 mL urine (P urine (P urine. Lower results of leukocytes, erythrocytes, squamous cells and non-hyaline casts were recorded in recommended procedures (centrifugation at 400xg, suction of supernatant, conical tube, 5 mL of sample) than in routine procedure (centrifugation at 1358xg, decanting of supernatant, round bottom tube, 10 mL) used in our laboratory.

  13. Study of the flow field past dimpled aerodynamic surfaces: numerical simulation and experimental verification

    Science.gov (United States)

    Binci, L.; Clementi, G.; D’Alessandro, V.; Montelpare, S.; Ricci, R.

    2017-11-01

    This work presents the study of the flow field past of dimpled laminar airfoil. Fluid dynamic behaviour of these elements has been not still deeply studied in the scientific community. Therefore Computational Fluid-Dynamics (CFD) is here used to analyze the flow field induced by dimples on the NACA 64-014A laminar airfoil at Re = 1.75 · 105 at α = 0°. Reynolds Averaged Navier–Stokes (RANS) equations and Large-Eddy Simulations (LES) were compared with wind tunnel measurements in order to evaluate their effectiveness in the modeling this kind of flow field. LES equations were solved using a specifically developed OpenFOAM solver adopting an L–stable Singly Diagonally Implicit Runge–Kutta (SDIRK) technique with an iterated PISO-like procedure for handling pressure-velocity coupling within each RK stage. Dynamic Smagorinsky subgrid model was employed. LES results provided good agreement with experimental data, while RANS equations closed with \\[k-ω -γ -\\overset{}{\\mathop{{{\\operatorname{Re}}θ, \\text{t}}}} \\] approach overstimates laminar separation bubble (LSB) extension of dimpled and un–dimpled configurations. Moreover, through skin friction coefficient analysis, we found a different representation of the turbulent zone between the numerical models; indeed, with RANS model LSB seems to be divided in two different parts, meanwhile LES model shows a LSB global reduction.

  14. Numerical study on the lubrication performance of compression ring-cylinder liner system with spherical dimples.

    Science.gov (United States)

    Liu, Cheng; Lu, Yan-Jun; Zhang, Yong-Fang; Li, Sha; Müller, Norbert

    2017-01-01

    The effects of surface texture on the lubrication performance of a compression ring-cylinder liner system are studied in this paper. By considering the surface roughness of the compression ring and cylinder liner, a mixed lubrication model is presented to investigate the tribological behaviors of a barrel-shaped compression ring-cylinder liner system with spherical dimples on the liner. In order to determine the rupture and reformulation positions of fluid film accurately, the Jacoboson-Floberg-Olsson (JFO) cavitation boundary condition is applied to the mixed lubrication model for ensuring the mass-conservative law. On this basis, the minimum oil film thickness and average friction forces in the compression ring-cylinder liner system are investigated under the engine-like conditions by changing the dimple area density, radius, and depth. The wear load, average friction forces, and power loss of the compression ring-cylinder liner system with and without dimples are also compared for different compression ring face profiles. The results show that the spherical dimples can produce a larger reduction of friction in mixed lubrication region, and reduce power loss significantly in the middle of the strokes. In addition, higher reduction percentages of average friction forces and wear are obtained for smaller crown height or larger axial width.

  15. Experimental and numerical investigation of flow around a sphere with dimples for various flow regimes

    Directory of Open Access Journals (Sweden)

    Bogdanović-Jovanović Jasmina B.

    2012-01-01

    Full Text Available Flow over a sphere is a typical bluff-body flow with many engineering applications. However, it has not been studied in depth, as compared to flow over a circular cylinder, because of the difficulties in the experimental set-up as well as in the computational approach for studying flow over a sphere. The main challenges are to understand the flow hydrodynamics and to clarify the flow pattern around a dimpled sphere because the flow pattern complying with the dimple structure on its surface is very complicated. In this paper experimental and numerical investigations of the fluid flow around a sphere with dimples, are represented. The sphere with dimples is placed in a quadratic cross section duct (measuring section and numerical simulation results are obtained by solving RANS equations. Furthermore, experimental measurements are carried out using a Laser-Doppler Anemometer (LDA. Experimental and numerical results of flow velocity fields were compared for three different flow regimes (Re=8×103, 2×104 and 4×104. Numerical investigation was performed for wide range of Reynolds numbers (Re=270%106. The final purpose of this paper is experimental and numerical determination of velocity field, separation point, pressure and drag coefficient, the length of reverse flow region in the wake and RANS turbulent model which gives the best results for engineering practice.

  16. Experimental Study of Thermo-hydraulic Characteristics of Surfaces with In-line Dimple Arrangement

    Directory of Open Access Journals (Sweden)

    S. A. Burtsev

    2015-01-01

    Full Text Available The paper presents a conducted experimental study of the heat exchange intensification on the surfaces covered with a regular vortex-generating relief that is an in-line array of the shallow hemispherical dimples. Using 12 configuration options with the Reynolds numbers in the range of (0.2-7.0 106 as an example, it analyses how a longitudinal and cross step of the in-line dimple array (density dimples effects on the processes of heat exchange intensification and resistance.The monocomponent strain-gauge balance allows us to define a value of the resistance coefficient by direct weighing of models (located in parallel in a flow of "relief" and smooth "reference" ones being under study. Distribution fields of heat – transfer factor are determined by recording a cooling process of the surface of studied models having high spatial and temporary resolution. All researches were conducted with one-shot data record of these thermal and hydraulic measurements for the smooth (reference surfaces and the studied surfaces covered with a regular vortex-generating relief (dimples. The error of determined parameters was no more than ±5%.The oil-sooty method allows us to visualize flow around a regular relief and obtain a flow pattern for 12 options of dimples configuration. The analysis has been carried out and a compliance of the flow patterns with the field of heat-transfer factors has been obtained.It has been found that for the in-line configuration a Reynolds analogy factor for most models is nonlinearly dependent on the Reynolds number. The friction intensification, at first, falls (to some Reynolds number and, further, starts increasing, tending to the friction intensification value with self-similarity flow around. Thus with increasing Reynolds number, the heattransfer factor intensification falls (more slowly than resistance intensification.

  17. Pressure drop-flow rate curves for single-phase steam in Combustion Engineering type steam generator U-tubes during severe accidents

    Energy Technology Data Exchange (ETDEWEB)

    Fynan, Douglas A.; Ahn, Kwang-Il, E-mail: kiahn@kaeri.re.kr

    2016-12-15

    Highlights: • Pressure drop-flow rate curves for superheated steam in U-tubes were generated. • Forward flow of hot steam is favored in the longer and taller U-tubes. • Reverse flow of cold steam is favored in short U-tubes. • Steam generator U-tube bundle geometry and tube diameter are important. • Need for correlation development for natural convention heat transfer coefficient. - Abstract: Characteristic pressure drop-flow rate curves are generated for all row numbers of the OPR1000 steam generators (SGs), representative of Combustion Engineering (CE) type SGs featuring square bend U-tubes. The pressure drop-flow rate curves are applicable to severe accident natural circulations of single-phase superheated steam during high pressure station blackout sequences with failed auxiliary feedwater and dry secondary side which are closely related to the thermally induced steam generator tube rupture event. The pressure drop-flow rate curves which determine the recirculation rate through the SG tubes are dependent on the tube bundle geometry and hydraulic diameter of the tubes. The larger CE type SGs have greater variation of tube length and height as a function of row number with forward flow of steam favored in the longer and taller high row number tubes and reverse flow favored in the short low row number tubes. Friction loss, natural convection heat transfer coefficients, and temperature differentials from the primary to secondary side are dominant parameters affecting the recirculation rate. The need for correlation development for natural convection heat transfer coefficients for external flow over tube bundles currently not modeled in system codes is discussed.

  18. Compact ILU-type electron accelerators as a base for industrial 4-sided irradiation systems for cable and tubes

    International Nuclear Information System (INIS)

    Auslender, V.L.; Nekhaev, V.E.; Panfilov, A.D.; Tuvik, A.A.

    1999-01-01

    The ILU-type industrial electron accelerators are developed in BINP sins 1967. Their energy range is 0.7-4.0 MeV at beam power of 20-50 kW. The comparison of the irradiation results after bilateral and four-sided irradiation of cables and tubes is given. It is shown that the required electron energy and beam power in the case of four-sided irradiation are sufficiently lower than in the case of bilateral irradiation, resulting in an increase of productive rate of the process and improvement of treatment quality. The installations for four-sided irradiation of cables and tubes are based on the industrial electron accelerators type ILU

  19. Development and evaluation of one step single tube multiplex RT-PCR for rapid detection and typing of dengue viruses

    OpenAIRE

    Parida Manmohan; Shrivastava Ambuj; Santhosh SR; Dash Paban; Saxena Parag; Rao PV

    2008-01-01

    Abstract Background Dengue is emerging as a major public health concern in many parts of the world. The development of a one-step, single tube, rapid, and multiplex reverse transcription polymerase chain reaction (M-RT-PCR) for simultaneous detection and typing of dengue virus using serotype specific primers during acute phase of illness is reported. Results An optimal assay condition with zero background was established having no cross-reaction with closely related members of flavivirus (Jap...

  20. [Effectiveness of continuous infusion of tizanidine (Ternelin) via a feeding tube for patients with the mixed type of tetraplegia].

    Science.gov (United States)

    Hiejima, Ikuko; Kumada, Tomohiro; Nozaki, Fumihito; Hayasi, Anri; Miyajima, Tomoko; Fujii, Tatsuya

    2015-01-01

    Severe muscle hypertonia in patients with the mixed type of tetraplegia may be associated with significant deterioration in the quality of life of the patients. Intermittent use of oral muscle relaxant drugs, for example, Tizanidine (Ternelin), which is a fast-acting muscle relaxant, can provide relief from the severe hypertonia in these patients, but only for short durations. We conducted a retrospective study of the effect of continuous infusion of tizanidine via a feeding tube on the severe systemic muscle hypertonia in patients with the mixed type of tetraplegia. We mixed tizanidine with milk or other enteral nutrients and administered the mixture via a naso-duodenal tube at a constant infusion rate several hours to 5 patients with the mixed type of tetraplegia showing severe uncontrolled systemic hypertonia under intermittent treatment with oral muscle relaxant drugs. Significant relief from the systemic muscle hypertonia was obtained in 4 of the 5 patients with improvement of the quality of life of the patients, e. g., they could get adequate sleep. There were no serious side effects in any of the cases. We consider that continuous infusion of tizanidine via a feeding tube would be useful for the treatment of severe systemic hypertonia in patients in whom the symptom cannot be adequately controlled by intermittent use of oral muscle relaxant drugs.

  1. Control of diesel gaseous and particulate emissions with a tube-type wet electrostatic precipitator.

    Science.gov (United States)

    Saiyasitpanich, Phirun; Keener, Tim C; Lu, Mingming; Liang, Fuyan; Khang, Soon-Jai

    2008-10-01

    In this study, experiments were performed with a bench-scale tube-type wet electrostatic precipitator (wESPs) to investigate its effectiveness for the removal of mass- and number-based diesel particulate matter (DPM), hydrocarbons (HCs), carbon monoxide (CO), and oxides of nitrogen (NOx) from diesel exhaust emissions. The concentration of ozone (O3) present in the exhaust that underwent a nonthermal plasma treatment process inside the wESP was also measured. A nonroad diesel generator operating at varying load conditions was used as a stationary diesel emission source. The DPM mass analysis was conducted by means of isokinetic sampling and the DPM mass concentration was determined by a gravimetric method. An electrical low-pressure impactor (ELPI) was used to quantify the DPM number concentration. The HC compounds, n-alkanes, and polycyclic aromatic hydrocarbons (PAHs) were collected on a moisture-free quartz filter together with a PUF/XAD/PUF cartridge and extracted in dichloromethane with sonication. Gas chromatography (GC)/mass spectroscopy (MS) was used to determine HC concentrations in the extracted solution. A calibrated gas combustion analyzer (Testo 350) and an O3 analyzer were used for quantifying the inlet and outlet concentrations of CO and NOx (nitric oxide [NO] + nitrogen dioxide [NO2]), and O3 in the diesel exhaust stream. The wESP was capable of removing approximately 67-86% of mass- and number-based DPM at a 100% exhaust volumetric flow rate generated from 0- to 75-kW engine loads. At 75-kW engine load, increasing gas residence time from approximately 0.1 to 0.4 sec led to a significant increase of DPM removal efficiency from approximately 67 to more than 90%. The removal of n-alkanes, 16 PAHs, and CO in the wESP ranged from 31 to 57% and 5 to 38%, respectively. The use of the wESP did not significantly affect NOx concentration in diesel exhaust. The O3 concentration in diesel exhaust was measured to be less than 1 ppm. The main mechanisms

  2. Crystal structure and self-interaction of the type VI secretion tail-tube protein from enteroaggregative Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Badreddine Douzi

    Full Text Available The type VI secretion system (T6SS is a widespread machine used by bacteria to control their environment and kill or disable bacterial species or eukaryotes through toxin injection. The T6SS comprises a central tube formed of stacked hexamers of hemolysin co-regulated proteins (Hcp and terminated by a trimeric valine-glycine repeat protein G (VgrG component, the cell puncturing device. A contractile tail sheath, formed by the TssB and TssC proteins, surrounds this tube. This syringe-like machine has been compared to an inverted phage, as both Hcp and VgrG share structural homology with tail components of Caudovirales. Here we solved the crystal structure of a tryptophan-substituted double mutant of Hcp1 from enteroaggregative Escherichia coli and compared it to the structures of other Hcps. Interestingly, we observed that the purified Hcp native protein is unable to form tubes in vitro. To better understand the rationale for observation, we measured the affinity of Hcp1 hexamers with themselves by surface plasmon resonance. The intra-hexamer interaction is weak, with a KD value of 7.2 µM. However, by engineering double cysteine mutants at defined positions, tubes of Hcp1 gathering up to 15 stacked hexamers formed in oxidative conditions. These results, together with those available in the literature regarding TssB and TssC, suggest that assembly of the T6SS tube differs significantly from that of Sipho- or Myoviridae.

  3. Design of a PC Based Pressure Indicator Using Inductive Pick-up Type Transducer and Bourdon Tube Sensor

    OpenAIRE

    S. C. BERA; N. MANDAL; R. SARKAR; S. MAITY

    2009-01-01

    Bourdon tube is a mechanical type pressure sensor and the bourdon gauge measures gauge pressure of a process pipe line or a process tank. But it is a local indicator and special costlier techniques are required to transmit the reading of bourdon gauge to a remote distance. In the present paper, a very simple inductive pick-up type technique has been developed to transmit the reading of bourdon gauge to a remote distance in the form of 1-5 Volt D.C. signal. This signal has been optically isola...

  4. Microstructure, elastic deformation behavior and mechanical properties of biomedical β-type titanium alloy thin-tube used for stents.

    Science.gov (United States)

    Tian, Yuxing; Yu, Zhentao; Ong, Chun Yee Aaron; Kent, Damon; Wang, Gui

    2015-05-01

    Cold-deformability and mechanical compatibility of the biomedical β-type titanium alloy are the foremost considerations for their application in stents, because the lower ductility restricts the cold-forming of thin-tube and unsatisfactory mechanical performance causes a failed tissue repair. In this paper, β-type titanium alloy (Ti-25Nb-3Zr-3Mo-2Sn, wt%) thin-tube fabricated by routine cold rolling is reported for the first time, and its elastic behavior and mechanical properties are discussed for the various microstructures. The as cold-rolled tube exhibits nonlinear elastic behavior with large recoverable strain of 2.3%. After annealing and aging, a nonlinear elasticity, considered as the intermediate stage between "double yielding" and normal linear elasticity, is attributable to a moderate precipitation of α phase. Quantitive relationships are established between volume fraction of α phase (Vα) and elastic modulus, strength as well as maximal recoverable strain (εmax-R), where the εmax-R of above 2.0% corresponds to the Vα range of 3-10%. It is considered that the "mechanical" stabilization of the (α+β) microstructure is a possible elastic mechanism for explaining the nonlinear elastic behavior. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Needle subcision: a conservative treatment for facial dimpling after elimination of odontogenic infection source: a technical note.

    Science.gov (United States)

    Rahpeyma, Amin; Khajehahmadi, Saeedeh

    2014-12-01

    Extraoral skin fistula after resolution of odontogenic infection often resolves spontaneously, but in some cases, facial dimpling occur which needs revision surgery. This article evaluates the result of needle subcision for treatment of this condition, with or without dermal filler injection. Five patients with facial dimpling that was remained after elimination of odontogenic infection origin were evaluated. Subcision alone was used in four patients, and needle subcision followed by dermal filler was done in a patient. Facial dimpling in the chin (a case), mandibular lower border (two cases) as well as cheek skin (two cases) were treated by this method. All patients were satisfied with the cosmetic results. Six month after surgery, treatment outcomes were stable. Needle subcision is a simple and conservative method for correction of facial dimpling after elimination of odontogenic infection source.

  6. Modelling of the ultrasonic inspection of steel tubes with longitudinal defects; Modelisation du controle ultrasonore de tubes d`acier presentant des defauts de type ``entaille longitudinale``

    Energy Technology Data Exchange (ETDEWEB)

    Mephane, M

    1998-12-31

    A model has been developed in order to simulate the ultrasonic inspection of steel tubes in the Vallourec control configuration. The model permits to simulate the control of steel tubes showing longitudinal defects located near the internal or external surface of tubes which appear during the rolling process. To detect this kind of defect, the probe is placed in an incident place perpendicular to the tube`s axis. The probe is in front of the external surface of the tube. The main characteristics of the model is to assume that the field radiated in the material does not depend on the probe`s position. This assumption permits to treat separately the field retracted in the material and the interaction between the defect and the ultrasonic beam. The focal plane is located in the material, so the plane waves approximation is applied where the waves front are assumed plane and parallel. The parallel refracted beam becomes divergent after reflection on the internal surface of tube. To treat the beam divergence, an amplitude weighting coefficient is then calculated by mean of the energy conservation of a tube of rays before and after reflection, following the Snell laws. This model can predict the edge diffraction echoes, the echoes issued from the corner effect, and also the mode conversion echoes. It has been validated on artificial notches, and on some natural defects. A comparison between experimental and modelling results shows a good agreement. (author) 39 refs.

  7. Enhancement of Dimple Formability in Sheet Metals by 2-Step Forming

    International Nuclear Information System (INIS)

    Kim, Hasung; Kim, Minsoo; Lee, Hyungyil; Kim, Naksoo; Kim, Dongchoul

    2013-01-01

    In this study, a 2-step stamping model with an additional 1st stamping tool is proposed to reduce stamping flaws in the curved parts of a dimple in a nuclear fuel spacer grid. First, the strains of curved part of dimple are characterized via a comparison with strain solutions in pure bending. A reference 2a finite element (FE) model of 1-step stamping is then established, and the corresponding maximum strain is obtained. By varying the values of design variables of the 1st stamping tool in the 2-step stamping model, FE solutions are obtained to express the strain as a function of process variables, which provides the optimum values of process variables. Finally, applying these optimum values to a 3a FE model, we demonstrate the enhanced formability of the proposed 2-step stamping model

  8. Enhancement of Dimple Formability in Sheet Metals by 2-Step Forming

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hasung; Kim, Minsoo; Lee, Hyungyil; Kim, Naksoo; Kim, Dongchoul [Sogang Univ., Seoul (Korea, Republic of)

    2013-07-15

    In this study, a 2-step stamping model with an additional 1st stamping tool is proposed to reduce stamping flaws in the curved parts of a dimple in a nuclear fuel spacer grid. First, the strains of curved part of dimple are characterized via a comparison with strain solutions in pure bending. A reference 2a finite element (FE) model of 1-step stamping is then established, and the corresponding maximum strain is obtained. By varying the values of design variables of the 1st stamping tool in the 2-step stamping model, FE solutions are obtained to express the strain as a function of process variables, which provides the optimum values of process variables. Finally, applying these optimum values to a 3a FE model, we demonstrate the enhanced formability of the proposed 2-step stamping model.

  9. Nasal dimple as part of the 22q11.2 deletion syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Gripp, K.W.; Reed, L.A. [Children`s Hospital of Philadelphia, PA (United States); Emanuel, B.S. [Children`s Hospital of Philadelphia, PA (United States)]|[Univ. of Pennsylvania School of Medicine, Philadelphia, PA (United States)] [and others

    1997-03-31

    The phenotype of the 22q11.2 microdeletion syndrome is quite variable. We describe 2 patients with a 22q11.2 deletion and a dimpled nasal tip, which, we suggest can be the extreme of the broad or bulbous nose commonly found in the 22q11.2 deletion syndrome, and should not be confused with the more severe nasal abnormalities seen in frontonasal dysplasia. 11 refs., 2 figs.

  10. Numerical investigation of the effect of sphere dimples on the drag crisis and the Magnus effect

    Science.gov (United States)

    Li, Jing; Tsubokura, Makoto; Tsunoda, Masaya

    2015-11-01

    The present study investigates the flow over a golf ball and a smooth sphere around the critical Reynolds numbers under both stationary and self-spinning conditions by conducting Large-eddy simulations (LES) based on high resolution unstructured grids. For the stationary cases, the present calculation results validate the promotion of the drag crisis at a relatively lower Reynolds number due to the golf ball dimples. It also shows that the golf ball dimples have a limited effect on the time-dependent lateral force development in the subcritical regime, whereas the dimples are beneficial in suppressing the lateral force oscillations in the supercritical regimes. With spin parameter Γ = 0.1, the drag coefficients for the spinning smooth sphere increase slightly in all Reynolds number regimes when compared to the stationary cases, whereas for the spinning golf ball, the drag force decreases in the critical regime and increases in the supercritical regime. For both spinning models, the inverse Magnus effect was reproduced in the critical regime, whereas in the supercritical regime the ordinary Magnus force was generated. Relatively weaker lift forces were also observed in the cases of the spinning golf balls when compared to the spinning smooth spheres.

  11. Numerical investigation of the tribological performance of micro-dimple textured surfaces under hydrodynamic lubrication.

    Science.gov (United States)

    Li, Kangmei; Jing, Dalei; Hu, Jun; Ding, Xiaohong; Yao, Zhenqiang

    2017-01-01

    Surface texturing is an important approach for controlling the tribological behavior of friction pairs used in mechanical and biological engineering. In this study, by utilizing the method of three-dimensional computational fluid dynamics (CFD) simulation, the lubrication model of a friction pair with micro-dimple array was established based on the Navier-Stokes equations. The typical pressure distribution of the lubricant film was analyzed. It was found that a positive hydrodynamic pressure is generated in the convergent part of the micro-dimple, while a negative hydrodynamic pressure is generated in the divergent part. With suitable parameters, the total integration of the pressure is positive, which can increase the load-carrying capacity of a friction pair. The effects of the micro-dimple parameters as well as fluid properties on tribological performance were investigated. It was concluded that under the condition of hydrodynamic lubrication, the main mechanism for the improvement in the tribological performance is the combined effects of wedging and recirculation. Within the range of parameters investigated in this study, the optimum texture density is 13%, while the optimum aspect ratio varies with the Reynolds number. For a given Reynolds number, there exists a combination of texture density and aspect ratio at which the optimum tribological performance could be obtained. Conclusions from this study could be helpful for the design of texture parameters in mechanical friction components and even in artificial joints.

  12. Nonlinear buckling behaviour of spherical shells: barriers and symmetry-breaking dimples.

    Science.gov (United States)

    Hutchinson, John W; Thompson, J Michael T

    2017-05-13

    The nonlinear axisymmetric post-buckling behaviour of perfect, thin, elastic spherical shells subject to external pressure and their asymmetric bifurcations are characterized, providing results for a structure/loading combination with an exceptionally nonlinear buckling response. Immediately after the onset of buckling, the buckling mode localizes into a dimple at the poles. The relations among the pressure, the dimple amplitude and the change in volume of the shell are determined over a large range of pole deflections. These results allow accurate evaluation of criteria such as the Maxwell condition for which the energies in the unbuckled and buckled states are the same and evaluation of the influences of pressure versus volume-controlled loadings. Non-axisymmetric bifurcation from the axisymmetric state, which occurs deep into the post-buckling regime in the form of multi-lobed dimples, is also established and discussed.This article is part of the themed issue 'Patterning through instabilities in complex media: theory and applications.' © 2017 The Author(s).

  13. Leak-before-break concept for evaluation of flows detected in pressure tubes in a Candu type reactor

    International Nuclear Information System (INIS)

    Crespi, J.C.

    1992-01-01

    This paper reviews the role of the Leak-Before-Break concept for evaluation of flaws detected in cold-worked Zr 2.5% Nb pressure tubes in a CANDU type reactors. The acceptance criteria are intended to prevent failure by brittle fracture, plastic collapse of the ligament and delayed hydride cracking. The methodology developed here was of great help in order to establish the operative conditions for fuel channel garter springs repositioning by means of the SLA Rette tool at Embalse Nuclear Generating Station, Cordoba, Argentina. (author)

  14. Decorating Waste Cloth via Industrial Wastewater for Tube-Type Flexible and Wearable Sodium-Ion Batteries.

    Science.gov (United States)

    Zhu, Yun-Hai; Yuan, Shuang; Bao, Di; Yin, Yan-Bin; Zhong, Hai-Xia; Zhang, Xin-Bo; Yan, Jun-Min; Jiang, Qing

    2017-04-01

    To turn waste into treasure, a facile and cost-effective strategy is developed to revive electroless nickel plating wastewater and cotton-textile waste toward a novel electrode substrate. Based on the substrate, a binder-free PB@GO@NTC electrode is obtained, which exhibits superior electrochemical performance. Moreover, for the first time, a novel tube-type flexible and wearable sodium-ion battery is successfully fabricated. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Stress corrosion cracking of steam generator tube and primary pipe in PWR type nuclear power plants

    International Nuclear Information System (INIS)

    Zhang Weiguo; Gao Fengqin; Zhou Hongyi

    1993-01-01

    The behavior of stress corrosion cracking (SCC) is studied by slow strain rate test (SSRT), constant load test (CLT) and low frequency cyclic loading test (LFCLT). The purpose of these tests is to get the test data for evaluating the integrity of pressurized boundary of pipes in Qinshan and Guangdong nuclear power plants. Tested materials are 316 nuclear grade stainless steel (SS) for primary pipes in welded heat affected zone (WHAZ) and steam generator tubes, such as Incoloy-800, Inconel-600, Inconel-690 and 321 SS which are used for steam generator in PWR. The effects of material metallurgy, shot-peening treatment, tensile load, strain rate, cyclic load and water chemistry on the behavior of SCC are investigated

  16. Stress corrosion cracking of steam generator tube and primary pipe in PWR type nuclear power plants

    International Nuclear Information System (INIS)

    Zhang Weiguo; Gao Fengqin; Zhou Hongyi

    1992-03-01

    The behavior of stress corrosion cracking (SCC) was studied by slow strain rate test (SSRT), constant load test (CLT) and low frequency cyclic loading test (LFCLT). The purpose of these tests is to get the test data for evaluating the integrity of pressurized boundary of pipes in Qinshan and Guangdong nuclear power plants (NPPs). Tested materials are 316 nuclear grade stainless steel (SS) for primary pipes in welded heat affected zone (WHAZ) and tubes of heat transfer, such as Incoloy-800, Inconel-600 and 321 SS which are used for steam generator in PWR NPPs. The effects of material metallurgy, shot peening treatment, tensile load, strain rate, cyclic load and water chemistry on the behavior of SCC were considered

  17. Numerical Analysis of Shell-and-Tube Type Latent Thermal Energy Storage Performance with Different Arrangements of Circular Fins

    Directory of Open Access Journals (Sweden)

    Sebastian Kuboth

    2017-02-01

    Full Text Available Latent thermal energy storage (LTS systems are versatile due to their high-energy storage density within a small temperature range. In shell-and-tube type storage systems fins can be used in order to achieve enhanced charging and discharging power. Typically, circular fins are evenly distributed over the length of the heat exchanger pipe. However, it is yet to be proven that this allocation is the most suitable for every kind of system and application. Consequently, within this paper, a simulation model was developed in order to examine the effect of different fin distributions on the performance of shell-and-tube type latent thermal storage units at discharge. The model was set up in MATLAB Simulink R2015b (The MathWorks, Inc., Natick, MA, USA based on the enthalpy method and validated by a reference model designed in ANSYS Fluent 15.0 (ANSYS, Inc., Canonsburg, PA, USA. The fin density of the heat exchanger pipe was increased towards the pipe outlet. This concentration of fins was implemented linearly, exponentially or suddenly with the total number of fins remaining constant during the variation of fin allocations. Results show that there is an influence of fin allocation on storage performance. However, the average storage performance at total discharge only increased by three percent with the best allocation compared to an equidistant arrangement.

  18. Experimental Investigation of Average Heat-Transfer and Friction Coefficients for Air Flowing in Circular Tubes Having Square-Thread-Type Roughness

    Science.gov (United States)

    Sams, E. W.

    1952-01-01

    An investigation of forced-convection heat transfer and associated pressure drops was conducted with air flowing through electrically heated Inconel tubes having various degrees of square-thread-type roughness, an inside diameter of 1/2 inch, and a length of 24 inches. were obtained for tubes having conventional roughness ratios (height of thread/radius of tube) of 0 (smooth tube), 0.016, 0.025, and 0.037 over ranges of bulk Reynolds numbers up to 350,000, average inside-tube-wall temperatures up to 1950deg R, and heat-flux densities up to 115,000 Btu per hour per square foot. Data The experimental data showed that both heat transfer and friction increased with increase in surface roughness, becoming more pronounced with increase in Reynolds number; for a given roughness, both heat transfer and friction were also influenced by the tube wall-to-bulk temperature ratio. Good correlation of the heat-transfer data for all the tubes investigated was obtained by use of a modification of the conventional Nusselt correlation parameters wherein the mass velocity in the Reynolds number was replaced by the product of air density evaluated at the average film temperature and the so-called friction velocity; in addition, the physical properties of air were evaluated at the average film temperature. The isothermal friction data for the rough tubes, when plotted in the conventional manner, resulted in curves similar to those obtained by other investigators; that is, the curve for a given roughness breaks away from the Blasius line (representing turbulent flow in smooth tubes) at some value of Reynolds number, which decreases with increase in surface roughness, and then becomes a horizontal line (friction coefficient independent of Reynolds number). A comparison of the friction data for the rough tubes used herein indicated that the conventional roughness ratio is not an adequate measure of relative roughness for tubes having a square-thread-type element. The present data, as well

  19. Bio-inspired low frictional surfaces having micro-dimple arrays prepared with honeycomb patterned porous films as wet etching masks.

    Science.gov (United States)

    Saito, Y; Yabu, H

    2015-01-27

    Some kinds of snakes have micro-dimple arrays on their skins and show low frictional properties. Cost-effective and simple preparation methods of surfaces having micro-dimple arrays without burrs have been required. In this study, micro-dimple arrays were successfully prepared on aluminum plates and pipes by using honeycomb patterned porous films as wet etching masks. Resulting surfaces having 5 and 8 μm dimple diameters show low frictional coefficients compared with polished surfaces at a fluid lubrication regime.

  20. Comparative study on the influence of depth, number and arrangement of dimples on the flow and heat transfer characteristics at turbulent flow regimes

    Science.gov (United States)

    Nazari, Saeed; Zamani, Mahdi; Moshizi, Sajad A.

    2018-03-01

    The ensuing study is dedicated to a series of numerical investigations concerning the effects of various geometric parameters of dimpled plates on the flow structure and heat transfer performance in a rectangular duct compared to the smooth plate. These parameters are the arrangement, number and depth of dimples. Two widely used staggered and square patterns in addition to a triangular arrangement, and three dimple depths (Δ = δ/d = 0.25, 0.375 and 0.5) have been chosen for this particular study. All studies have been conducted at three different Reynolds numbers Re = 25,000, 50,000 and 100,000. In order to capture the flow structures in the vicinity of dimples and contributing phenomena related to the boundary layer interactions, fully structured grids with y+ rims of dimples are the causes for improved average Nusselt number in the dimpled surface in comparison to the smooth plate. However, more pressure loss due to the higher friction drag and recirculation zones inside dimples will exist as a drawback in this system. Moreover, for all arrangements increasing dimple ratio Δ has a negative impact on the heat transfer augmentation and also deteriorates the pressure loss, which leads to this fact that Δ = 0.25 serves as the best option for the dimple depth.

  1. Design of a PC Based Pressure Indicator Using Inductive Pick-up Type Transducer and Bourdon Tube Sensor

    Directory of Open Access Journals (Sweden)

    S. C. BERA

    2009-08-01

    Full Text Available Bourdon tube is a mechanical type pressure sensor and the bourdon gauge measures gauge pressure of a process pipe line or a process tank. But it is a local indicator and special costlier techniques are required to transmit the reading of bourdon gauge to a remote distance. In the present paper, a very simple inductive pick-up type technique has been developed to transmit the reading of bourdon gauge to a remote distance in the form of 1-5 Volt D.C. signal. This signal has been optically isolated to design a PC based pressure indicator using Labtech Note Book Pro software. The theoretical analysis of the whole technique has been presented in the paper. The instrument developed using this technique has been experimentally tested and the experimental results are reported in the paper. A good linearity and repeatability of the instrument has been observed.

  2. Tribological investigation of diamond-like carbon coated micro-dimpled surface under bovine serum and osteoarthritis oriented synovial fluid

    Science.gov (United States)

    Ghosh, Subir; Choudhury, Dipankar; Roy, Taposh; Mamat, Azuddin Bin; Masjuki, H. H.; Pingguan-Murphy, Belinda

    2015-06-01

    Osteoarthritis-oriented synovial fluid (OASF), i.e., that typical of a patient with osteoarthritis, has different physical and biological characteristics than bovine serum (BS), a lubricant widely used in biotribological investigations. Micro-dimpled and diamond-like carbon- (DLC) coated surfaces are key emerging interfaces for orthopedic implants. In this study, tribological performances of dimpled surfaces, with and without DLC coating, have been investigated under both BS and OASF. The friction tests were performed utilizing a pin on a disk tribometer, whereas contact pressure, speed, and temperature were simulated to a ‘medium walking gait’ of hip joint conditions. The mechanical properties of the specimen and the physical properties of the lubricant were characterized before the friction test. Raman analysis was conducted to identify the coating condition both before and after the test. The DLC-coated dimpled surface showed maximum hardness and residual stress. A DLC-coated dimpled surface under an OASF lubricated condition yielded a lower friction coefficient and wear compared to those of plain and dimpled specimens. The higher graphitization of coated materials with increasing load was confirmed by Raman spectroscopy.

  3. Tribological investigation of diamond-like carbon coated micro-dimpled surface under bovine serum and osteoarthritis oriented synovial fluid

    International Nuclear Information System (INIS)

    Ghosh, Subir; Roy, Taposh; Pingguan-Murphy, Belinda; Choudhury, Dipankar; Bin Mamat, Azuddin; Masjuki, H H

    2015-01-01

    Osteoarthritis-oriented synovial fluid (OASF), i.e., that typical of a patient with osteoarthritis, has different physical and biological characteristics than bovine serum (BS), a lubricant widely used in biotribological investigations. Micro-dimpled and diamond-like carbon- (DLC) coated surfaces are key emerging interfaces for orthopedic implants. In this study, tribological performances of dimpled surfaces, with and without DLC coating, have been investigated under both BS and OASF. The friction tests were performed utilizing a pin on a disk tribometer, whereas contact pressure, speed, and temperature were simulated to a ‘medium walking gait’ of hip joint conditions. The mechanical properties of the specimen and the physical properties of the lubricant were characterized before the friction test. Raman analysis was conducted to identify the coating condition both before and after the test. The DLC-coated dimpled surface showed maximum hardness and residual stress. A DLC-coated dimpled surface under an OASF lubricated condition yielded a lower friction coefficient and wear compared to those of plain and dimpled specimens. The higher graphitization of coated materials with increasing load was confirmed by Raman spectroscopy. (paper)

  4. Tribological investigation of diamond-like carbon coated micro-dimpled surface under bovine serum and osteoarthritis oriented synovial fluid

    Science.gov (United States)

    Ghosh, Subir; Choudhury, Dipankar; Roy, Taposh; Bin Mamat, Azuddin; Masjuki, H H; Pingguan-Murphy, Belinda

    2015-01-01

    Osteoarthritis-oriented synovial fluid (OASF), i.e., that typical of a patient with osteoarthritis, has different physical and biological characteristics than bovine serum (BS), a lubricant widely used in biotribological investigations. Micro-dimpled and diamond-like carbon- (DLC) coated surfaces are key emerging interfaces for orthopedic implants. In this study, tribological performances of dimpled surfaces, with and without DLC coating, have been investigated under both BS and OASF. The friction tests were performed utilizing a pin on a disk tribometer, whereas contact pressure, speed, and temperature were simulated to a ‘medium walking gait’ of hip joint conditions. The mechanical properties of the specimen and the physical properties of the lubricant were characterized before the friction test. Raman analysis was conducted to identify the coating condition both before and after the test. The DLC-coated dimpled surface showed maximum hardness and residual stress. A DLC-coated dimpled surface under an OASF lubricated condition yielded a lower friction coefficient and wear compared to those of plain and dimpled specimens. The higher graphitization of coated materials with increasing load was confirmed by Raman spectroscopy. PMID:27877803

  5. Numerical and Experimental Investigation for Heat Transfer Enhancement by Dimpled Surface Heat Exchanger in Thermoelectric Generator

    Science.gov (United States)

    Wang, Yiping; Li, Shuai; Yang, Xue; Deng, Yadong; Su, Chuqi

    2016-03-01

    For vehicle thermoelectric exhaust energy recovery, the temperature difference between the heat exchanger and the coolant has a strong influence on the electric power generation, and ribs are often employed to enhance the heat transfer of the heat exchanger. However, the introduction of ribs will result in a large unwanted pressure drop in the exhaust system which is unfavorable for the engine's efficiency. Therefore, how to enhance the heat transfer and control the pressure drop in the exhaust system is quite important for thermoelectric generators (TEG). In the current study, a symmetrical arrangement of dimpled surfaces staggered in the upper and lower surfaces of the heat exchanger was proposed to augment heat transfer rates with minimal pressure drop penalties. The turbulent flow characteristics and heat transfer performance of turbulent flow over the dimpled surface in a flat heat exchanger was investigated by numerical simulation and temperature measurements. The heat transfer capacity in terms of Nusselt number and the pressure loss in terms of Fanning friction factors of the exchanger were compared with those of the flat plate. The pressure loss and heat transfer characteristics of dimples with a depth-to-diameter ratio ( h/D) at 0.2 were investigated. Finally, a quite good heat transfer performance with minimal pressure drop heat exchanger in a vehicle TEG was obtained. And based on the area-averaged surface temperature of the heat exchanger and the Seeback effect, the power generation can be improved by about 15% at Re = 25,000 compared to a heat exchanger with a flat surface.

  6. Friction pressure drop and heat transfer coefficient of two-phase flow in helically coiled tube once-through steam generator for integrated type marine water reactor

    International Nuclear Information System (INIS)

    Nariai, Hideki; Kobayashi, Michiyuki; Matsuoka, Takeshi.

    1982-01-01

    Two-phase friction pressure drop and heat transfer coefficients in a once-through steam generator with helically coiled tubes were investigated with the model test rig of an integrated type marine water reactor. As the dimensions of the heat transfer tubes and the thermal-fluid conditions are almost the same as those of real reactors, the data applicable directly to the real reactor design were obtained. As to the friction pressure drop, modified Kozeki's prediction which is based on the experimental data by Kozeki for coiled tubes, agreed the best with the experimental data. Modified Martinelli-Nelson's prediction which is based on Martinelli-Nelson's multiplier using Ito's equation for single-phase flow in coiled tube, agreed within 30%. The effect of coiled tube on the average heat transfer coefficients at boiling region were small, and the predictions for straight tube could also be applied to coiled tube. Schrock-Grossman's correlation agreed well with the experimental data at the pressures of lower than 3.5 MPa. It was suggested that dryout should be occurred at the quality of greater than 90% within the conditions of this report. (author)

  7. The evaluation of the micro-tracks and micro-dimples on the tribological characteristics of thrust ball bearings.

    Science.gov (United States)

    Amanov, Auezhan; Pyoun, Young-Shik; Cho, In-Shik; Lee, Chang-Soon; Park, In-Gyu

    2011-01-01

    One of the primary remedies for tribological problems is surface modification. The reduction of the friction between the ball and the raceway of bearings is a very important goal of the development of bearing technology. A low friction has a positive effect in terms of the extension of the fatigue life, avoidance of a temperature rise, and prevention of premature failure of bearings. Therefore, this research sought to investigate the effects of micro-tracks and micro-dimples on the tribological characteristics at the contact point between the ball and the raceway of thrust ball bearings (TBBs). The ultrasonic nanocrystal surface modification (UNSM) technology was applied using different intervals (feed rates) to the TBB raceway surface to create micro-tracks and micro-dimples. The friction coefficient after UNSM at 50 microm intervals showed marked sensitivity and a significant reduction of 30%. In this study, the results showed that more micro-dimples yield a lower friction coefficient.

  8. Study of cyclic thermal aging of tube type receivers as a function of the duration of the cycle

    Science.gov (United States)

    Setien, Eneko; Fernández-Reche, Jesús; Ariza, María Jesús; Álvarez-de-Lara, Mónica

    2017-06-01

    The tube type receivers are exposed to variable duration cyclic operating conditions, which can jeopardize its reliability, and make it hard to estimate its long term performance. The designers have to deal with this problem and estimate the receiver long term performance based on the poor available litterature and the data sheets of the material. In order to help the designer better estimate the performance of the receivers, in this paper the cyclic thermal aging is analyzed as a function of the cycle duration. For this purpose, coated and uncoated Inconel alloy 625 tubular samples, similar to those used in the commercial receivers, are cyclically aged with different thermal cycle duration. The aging of these samples has been analyzed by means of oxidation kinetics, microstructure examination and mechanical and optical properties. The effect of the thermal cycle duration is studied and discussed by comparison of the results.

  9. Sacral Dimple

    Science.gov (United States)

    ... A very mild form of this condition, called spina bifida occulta, occurs when the spine doesn't close properly ... remains within the spinal canal. In most cases, spina bifida occulta causes no symptoms. Tethered cord syndrome. The spinal ...

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  11. Enhancement of dimple formability in sheet metals by 2-step forming

    International Nuclear Information System (INIS)

    Kim, Minsoo; Bang, Sungsik; Lee, Hyungyil; Kim, Naksoo; Kim, Dongchoul

    2014-01-01

    Highlights: • Suggested 2-step model aims at a lower susceptibility to cracking. • Strain at weak point could be reduced by 16% compared to 1-step model. • A more uniform thickness distribution is achieved by the 2-step model. • The maximum stress in the FLSD and the GTN damage variable reduced at the weak point. • The 2-step model provides an enhanced formability compared to the 1-step model. - Abstract: In this study, a 2-step stamping model with an additional 1st stamping tool is proposed to reduce stamping flaws in the curved parts of dimples in nuclear fuel spacer grids. First, the strains in the curved part of the dimple are analyzed and compared with strain solutions for pure bending. A reference 2D FE (finite element) model of the 1-step stamping is established, and the corresponding maximum strain is obtained. FE solutions are obtained for various process variable values for the 1st stamping tool used in the 2-step stamping model. Based on these solutions and applying the RSM (response surface method), strains are expressed as a function of process variables. This function then serves to evaluate optimum process variable values. Finally, by transferring these optimum values to a 3D FE model, we confirm the enhanced formability of the proposed 2-step stamping model

  12. A Maugis-Dugdale cohesive solution for adhesion of a surface with a dimple.

    Science.gov (United States)

    Papangelo, A; Ciavarella, M

    2017-02-01

    We study the adhesion of a surface with a 'dimple' which shows a mechanism for a bi-stable adhesive system in surfaces with spaced patterns of depressions, leading to adhesion enhancement, high dissipation and hysteresis. Recent studies were limited mainly to the very short range of adhesion (the so-called JKR regime), while we generalize the study to a Maugis cohesive model. A 'generalized Tabor parameter', given by the ratio of theoretical strength to elastic modulus, multiplied by the ratio of dimple width to depth has been found. It is shown that bistability disappears for generalized Tabor parameter less than about 2. Introduction of the theoretical strength is needed to have significant results when the system has gone in full contact, unless one postulates alternative limits to full contact, such as air entrapment, contaminants or fine scale roughness. Simple equations are obtained for the pull-off and for the full contact pressure in the entire set of the two governing dimensionless parameters. A qualitative comparison with results of recent experiments with nanopatterned bioinspired dry adhesives is attempted in light of the present model. © 2017 The Author(s).

  13. An elastic dimpling instability with Kosterlitz-Thouless character and a precursor role in creasing

    Science.gov (United States)

    Engstrom, Tyler; Paulsen, Joseph; Schwarz, Jennifer

    Creasing instability, also known as sulcification, occurs in a variety of quasi-2d elastic systems subject to compressive plane strain, and has been proposed as a mechanism of brain folding. While the dynamics of pre-existing creases can be understood in terms of crack propagation, a detailed critical phenomena picture of the instability is lacking. We show that surface dimpling is an equilibrium phase transition, and can be described in a language of quasi-particle excitations conceptualized as ``ghost fibers'' within the shear lag model. Tension-compression pairs (dipoles) of ghost fibers are energetically favorable at low strains, and the pairs unbind at a critical compressive plane strain, analogously to vortices in the Kosterlitz-Thouless transition. This dimpling transition bears strong resemblance to the creasing instability. We argue that zero-length creases are ghost fibers, which are a special case of ``ghost slabs''. Critical strain of a ghost slab increases linearly with its length, and is independent of both shear modulus and system thickness.

  14. Strategies to prevent ventilation-associated pneumonia: the effect of cuff pressure monitoring techniques and tracheal tube type on aspiration of subglottic secretions: an in-vitro study.

    Science.gov (United States)

    Carter, Eleanor L; Duguid, Alasdair; Ercole, Ari; Matta, Basil; Burnstein, Rowan M; Veenith, Tonny

    2014-03-01

    Ventilation-associated pneumonia (VAP) is the commonest nosocomial infection in intensive care. Implementation of a VAP prevention care bundle is a proven method to reduce its incidence. The UK care bundle recommends maintenance of the tracheal tube cuff pressure at 20 to 30  cmH₂O with 4-hourly pressure checks and use of tracheal tubes with subglottic aspiration ports in patients admitted for more than 72  h. To evaluate the effects of tracheal tube type and cuff pressure monitoring technique on leakage of subglottic secretions past the tracheal tube cuff. Bench-top study. Laboratory. A model adult trachea with simulated subglottic secretions was intubated with a tracheal tube with the cuff inflated to 25  cmH₂O. Experiments were conducted using a Portex Profile Soft Seal tracheal tube with three cuff pressure monitoring strategies and using a Portex SACETT tracheal tube with intermittent cuff pressure checks. Rate of simulated secretion leakage past the tracheal tube cuff. Mean ± SD leakage of fluid past the Profile Soft Seal tracheal tube cuff was 2.25 ± 1.49  ml  min⁻¹ with no monitoring of cuff pressure, 2.98 ± 1.63  ml  min⁻¹ with intermittent cuff pressure monitoring and 3.83 ± 2.17  ml  min⁻¹ with continuous cuff pressure monitoring (P aspiration port and aspirating the simulated secretions prior to intermittent cuff pressure checks reduced the leakage rate to 0.50 ± 0.48  ml  min⁻¹ (P aspiration port. Further evaluation of medical device performance is needed in order to design more effective VAP prevention strategies.

  15. The effect of priming solutions and storage time on plasticizer migration in different PVC tubing types--implications for wet storage of ECMO systems.

    Science.gov (United States)

    Horne, David C; Torrance, Ida; Modine, Thomas; Gourlay, Terence

    2009-12-01

    The wet priming of extracorporeal membrane oxygenation systems and storage of these systems for rapid deployment is common practice in many clinical centers. This storage policy is, however, seen by many to be controversial due to the potential adverse effects associated with the migration of the di(2-ethylhexyl) phthalate plasticizer (DEHP) from the polyvinyl chloride (PVC) circuit tubing and issues surrounding the maintenance of sterility. This study was performed to evaluate the effects of both short and long-term storage and priming fluid type on plasticizer migration from four commonly used PVC tubes in extracorporeal membrane oxygenation therapy circuits. The four tubes incorporating three plasticizers, two DEHP, one tri(2-ethylhexyl) trimellitate (TOTM), and one dioctyl adipate (DOA) were exposed to each of the three priming fluids for a period of 28 days. Samples were taken at time intervals of 1, 4, 8, 24, and 48 hours, followed by samples at 7, 14, and 28 days. Each sample was processed using a spectrophotomer and the concentration of plasticizer leaching into each solution at each time-point determined. There was a time dependent increase in plasticizer leached from each tube. The migration was greatly affected by both the priming fluid and tubing type. The migration of DEHP was higher than that of TOTM and DOA over both the short and long-term exposure levels. Plasticizer migration occurs from all of the tubes tested over the long term. The TOTM and DOA tubes performed better than the DEHP counterparts in the short term. Selection of priming fluid has a major bearing on plasticizer migration with significant lipid and protein containing fluids promoting higher migration than simple sodium chloride .9% solution prime. The results suggest that DOA tubing and sodium chloride. 9% solution priming fluid should be selected if wet primed perfusion circuits are to be used over short terms of storage.

  16. Development and evaluation of one step single tube multiplex RT-PCR for rapid detection and typing of dengue viruses

    Directory of Open Access Journals (Sweden)

    Parida Manmohan

    2008-01-01

    Full Text Available Abstract Background Dengue is emerging as a major public health concern in many parts of the world. The development of a one-step, single tube, rapid, and multiplex reverse transcription polymerase chain reaction (M-RT-PCR for simultaneous detection and typing of dengue virus using serotype specific primers during acute phase of illness is reported. Results An optimal assay condition with zero background was established having no cross-reaction with closely related members of flavivirus (Japanese encephalitis, West Nile, Yellow fever and alphavirus (Chikungunya. The feasibility of M-RT-PCR assay for clinical diagnosis was validated with 620 acute phase dengue patient sera samples of recent epidemics in India. The comparative evaluation vis a vis conventional virus isolation revealed higher sensitivity. None of the forty healthy serum samples screened in the present study revealed any amplification, thereby establishing specificity of the reported assay for dengue virus only. Conclusion These findings clearly suggested that M-RT-PCR assay reported in the present study is the rapid and cost-effective method for simultaneous detection as well as typing of the dengue virus in acute phase patient serum samples. Thus, the M-RT-PCR assay developed in this study will serve as a very useful tool for rapid diagnosis and typing of dengue infections in endemic areas.

  17. Studying the heat transfer in chess-type bundles of smooth and ribbed tubes in boiling layers

    International Nuclear Information System (INIS)

    Zhitomirskaya, I.V.; Migaj, V.K.; Rassudov, N.S.; Shemyakin, V.N.

    1982-01-01

    Heat transfer between horizontal bundles of steel smooth and ribbed tubes and fluidized bed of large-dispersed packing of balls from 2.8 upto 4 mm in diameter is investigated. The heat transfer has been investigated by stationary methods by means of alpha calorimeters representing parts of the investigated tubes with electric heaters mounted inside them. The results obtained show that the heat removal per carrying tube surface increases by 1.92 times at the ribbing coefficient equal to 3.6. This testifies to the decrease in heat transfer coefficient per total surface of the tube. The conclusion is drawn on the efficiency of ribbed tube application in small size heat exchangers and necessity of further investigations in the direction of search for optimal configuration of tube bundles with a developed external surface

  18. Numerical and model validation of uncovered nanofluid sheet and tube type photovoltaic thermal solar system

    International Nuclear Information System (INIS)

    Rejeb, Oussama; Sardarabadi, Mohammad; Ménézo, Christophe; Passandideh-Fard, Mohammad; Dhaou, Mohamed Houcine; Jemni, Abdelmajid

    2016-01-01

    Highlights: • A numerical model applied to analyze an uncovered nanofluid based PVT collector. • The model included nanoparticle concentration, types and different base fluids. • Numerical model are performed on Al 2 O 3 and CuO nanoparticles (1, 2 and 4 wt %). - Abstract: In this paper, an experimental and numerical study is performed to evaluate the performance of a photovoltaic thermal (PV/T) nanofluid based collector. A two-dimensional numerical model is established to study the effects of using nanofluids as working fluid in PV/T collector. The model is validated experimentally by comparing the simulations with the experimental results. The influence of concentration (0.1, 0.2 and 0.4 wt.%), types of nanoparticles (Al 2 O 3 and Cu) and different base fluids (pure water and ethylene glycol) on the electrical and thermal performance of the collector is investigated. Also, the model is applied to predict the annual electrical and thermal output of the PV/T for three different cities: Lyon (France), Mashhad (Iran) and Monastir (Tunisia). The results indicated that using pure water as a base fluid provides a higher performance in comparison with ethylene glycol. Using Cu/water gives the best thermal and electrical efficiency in comparison to Cu/ethylene glycol, Al 2 O 3 /water and Al 2 O 3 /ethylene glycol. It is also found that the thermal and electrical energy output for Monastir (Tunisia) climate condition is higher than that of Mashhad (Iran) and Lyon (France).

  19. Proposed examination of defect detection of magnetic tube where alternating probe in type of insertion is used

    International Nuclear Information System (INIS)

    Kiya, Atsushi; Gotoh, Yuji; Sakurai, Kenta

    2008-01-01

    In various plants in the thermal power plant and the nuclear plant, a lot of steel tubes are used for various places such as heat exchangers, and these steel tubes should inspect regular for a healthy securing of the plant. Then, the outer side defect inspection of the magnetic substance steel tube using an electromagnetic phenomenon was examined in this research. It is shown that the inspection of the outer side defect on a steel tube with baffle is possible using the proposed method. (author)

  20. Nanoscale aluminum dimples for light-trapping in organic thin-films

    DEFF Research Database (Denmark)

    Goszczak, Arkadiusz Jaroslaw; Adam, Jost; Cielecki, Pawel Piotr

    absorption improvement in the active layer of the devices. A prospective, cheap and large-scale compatible method for structuring the electrodes in OSCs arises by the use of anodic aluminum oxide (AAO) membranes. In the present work, aluminum films of high purity and low roughness are formed via e......-beam evaporation of a few nanometers of aluminum followed by a micrometer layer of aluminum formed via sputter deposition. The samples are then anodized to form nano-scale pores of controlled sizes. The anodization of the prepared samples occurs in an electrochemical cell in H2SO4, H2C2O4 and H3PO4 solutions....... Electrolyte solution variation and anodization parameters (sample temperature, voltage) control, allows for AAO pore diameter and interpore distance tuning. The fabricated AAO is selectively etched in H2CrO4/H3PO4 mixtures, in order to reveal the underlying aluminum nanoscale dimples, which are present...

  1. Dimple coalescence and liquid droplets distributions during phase separation in a pure fluid under microgravity.

    Science.gov (United States)

    Oprisan, Ana; Oprisan, Sorinel A; Hegseth, John J; Garrabos, Yves; Lecoutre-Chabot, Carole; Beysens, Daniel

    2014-09-01

    Phase separation has important implications for the mechanical, thermal, and electrical properties of materials. Weightless conditions prevent buoyancy and sedimentation from affecting the dynamics of phase separation and the morphology of the domains. In our experiments, sulfur hexafluoride (SF6) was initially heated about 1K above its critical temperature under microgravity conditions and then repeatedly quenched using temperature steps, the last one being of 3.6 mK, until it crossed its critical temperature and phase-separated into gas and liquid domains. Both full view (macroscopic) and microscopic view images of the sample cell unit were analyzed to determine the changes in the distribution of liquid droplet diameters during phase separation. Previously, dimple coalescences were only observed in density-matched binary liquid mixture near its critical point of miscibility. Here we present experimental evidences in support of dimple coalescence between phase-separated liquid droplets in pure, supercritical, fluids under microgravity conditions. Although both liquid mixtures and pure fluids belong to the same universality class, both the mass transport mechanisms and their thermophysical properties are significantly different. In supercritical pure fluids the transport of heat and mass are strongly coupled by the enthalpy of condensation, whereas in liquid mixtures mass transport processes are purely diffusive. The viscosity is also much smaller in pure fluids than in liquid mixtures. For these reasons, there are large differences in the fluctuation relaxation time and hydrodynamics flows that prompted this experimental investigation. We found that the number of droplets increases rapidly during the intermediate stage of phase separation. We also found that above a cutoff diameter of about 100 microns the size distribution of droplets follows a power law with an exponent close to -2, as predicted from phenomenological considerations.

  2. Feeding Tubes

    Science.gov (United States)

    ... the TPN. Tubes Used for Enteral Feeds NG (Nasogastric Tube) A flexible tube is placed via the nose, ... portion of the small intestine Naso – nose NG – Nasogastric Tube -ostomy – new opening Percutaneous – through the skin PEJ – ...

  3. Experimental investigation of effect of spacer on two phase turbulent mixing rate in subchannels of pressure tube type BWR

    Energy Technology Data Exchange (ETDEWEB)

    Verma, Shashi Kant; Sinha, S.L. [National Institute of Technology, Raipur (India). Mechanical Engineering Dept.; Chandraker, D.K. [Bhabha Atomic Research Centre, Mumbai (India). Reactor Design and Development Group

    2017-11-15

    Turbulent mixing rate between adjacent subchannels in a two-phase flow has been known to be strongly dependent on the flow pattern. The most important aspect of turbulent motion is that the velocity and pressure at a fixed point do not remain constant with time even in steady state but go through very irregular high frequency fluctuations. These fluctuations influence the diffusion of scalar and vector quantities. The Advanced Heavy Water Reactor (AHWR) is a vertical pressure tube type, heavy water moderated and boiling light water cooled natural circulation based reactor. The fuel bundle of AHWR contains 54 fuel rods set in three concentric rings of 12, 18 and 24 fuel rods. This fuel bundle is divided into number of imaginary interacting flow channel called subchannels. Alteration from single phase to two phase flow situation occurs in reactor rod bundle with raise in power. The two phase flow regimes like bubbly, slug-churn, and annular flow are generally encountered in reactor rod bundle. Prediction of thermal margin of the reactor has necessitated the investigation of turbulent mixing rate of coolant between these subchannels under these flow regimes. Thus, it is fundamental to estimate the effect of spacer grids on turbulent mixing between subchannels of AHWR rod bundle.

  4. Modeling of heating and cooling performance of counter flow type vortex tube by using artificial neural network

    Energy Technology Data Exchange (ETDEWEB)

    Kocabas, Fikret [Bartin University, Faculty of Engineering, Civil Engineering Department, Bartin (Turkey); Korkmaz, Murat [Hacettepe University, Vocational High School, Department of Machinery, Polatli, Ankara (Turkey); Sorgucu, Ugur [Bartin University, Faculty of Engineering, Electrical and Electronics Engineering Department, Bartin (Turkey); Donmez, Senayi [Karatekin University Technical and Business College, Civil Engineering Department, Cankiri (Turkey)

    2010-08-15

    In this study, the effect of the nozzle number and the inlet pressures, which vary from 150 to 700 kPa with 50 kPa increments, on the heating and cooling performance of the counter flow type vortex tube has been modeled with an artificial neural network (ANN) and multi-linear regression (MLR) models by using the experimentally obtained data. In the developed system output parameter temperature gradiant between the cold and hot outlets ({delta}T) has been determined using inlet parameters such as the inlet pressure (P{sub inlet}), nozzle number (N), cold mass fraction ({mu}{sub c}) and inlet mass flow rate (m{sub inlet}). The back-propagation learning algorithm with variant which is Levenberg-Marquardt (LM) and Sigmoid transfer function have been used in the network. In addition, the statistical validity of the developed model has been determined by using the coefficient of determination (R{sup 2}), the root means square error (RMSE), and the relative absolute errors (RAE). R{sup 2}, RMSE and RAE have been determined for {delta}T as 0.9989, 0.5016, 0.0540 respectively. (author)

  5. Lifetime prediction and reliability estimation methodology for Stirling-type pulse tube refrigerators by gaseous contamination accelerated degradation testing

    Science.gov (United States)

    Wan, Fubin; Tan, Yuanyuan; Jiang, Zhenhua; Chen, Xun; Wu, Yinong; Zhao, Peng

    2017-12-01

    Lifetime and reliability are the two performance parameters of premium importance for modern space Stirling-type pulse tube refrigerators (SPTRs), which are required to operate in excess of 10 years. Demonstration of these parameters provides a significant challenge. This paper proposes a lifetime prediction and reliability estimation method that utilizes accelerated degradation testing (ADT) for SPTRs related to gaseous contamination failure. The method was experimentally validated via three groups of gaseous contamination ADT. First, the performance degradation model based on mechanism of contamination failure and material outgassing characteristics of SPTRs was established. Next, a preliminary test was performed to determine whether the mechanism of contamination failure of the SPTRs during ADT is consistent with normal life testing. Subsequently, the experimental program of ADT was designed for SPTRs. Then, three groups of gaseous contamination ADT were performed at elevated ambient temperatures of 40 °C, 50 °C, and 60 °C, respectively and the estimated lifetimes of the SPTRs under normal condition were obtained through acceleration model (Arrhenius model). The results show good fitting of the degradation model with the experimental data. Finally, we obtained the reliability estimation of SPTRs through using the Weibull distribution. The proposed novel methodology enables us to take less than one year time to estimate the reliability of the SPTRs designed for more than 10 years.

  6. Probable causes of damage of heat-exchange tubes of low-pressure-exchanges of PND-3 type and repair methods

    Science.gov (United States)

    Trifonov, N. N.; Esin, S. B.; Nikolaenkova, E. K.; Sukhorukov, Yu. G.; Svyatkin, F. A.; Sintsova, T. G.; Modestov, V. S.

    2017-08-01

    The structures of low-pressure heaters (LPH), which are installed at nuclear power plants with the K-1000-60/1500 type turbine plants are considered. It was revealed that only the PND-3 type low-pressure heaters have the damages of the heat exchange tubes. For a short operation life, the number of the damaged heat-exchange tubes of PND-3 is approximately 50 pcs for Kalinin NPP and 100-150 pcs for Balakovo NPP. The low-pressure heaters were manufactured at AO Ural Plant of Chemical Machine-Building "Uralkhimmash," OAO Taganrog Boiler-Making Works "Krasny Kotelshchik," and Vitkovice Machinery Group, but the damage nature of the heat-exchange tubes is identical for all PND-3. The damages occur in the place of passage of the heat exchange tubes through the first, the second, and the third partitions over the lower tube plate (the first path of the turbine condensate). Hydraulic shocks can be one of the possible causes of the damage of the heat-exchange tubes of PND-3. The analysis of the average thermal and dynamic loads of the tube systems of PND-1-PND-4 revealed that PND-3 by the thermal power are loaded 1.4-1.6 times and by the dynamic effects are loaded 1.8-2.0 times more than the remaining LPHs. Another possible cause of damage can be the cascaded drain of the separate into PND-4 and then through the drainage heat exchange into PND-3. An additional factor can be the structure of the condensate drainage unit. The advanced system of the heating steam flow and pumping scheme of the separate drain using the existing drainage pumps of PND-3 for K-1000-60/1500 turbine plants for Balakovo and Kalinin NPPs were proposed. The considered decisions make it possible to reduce the flow rate of the heating steam condensate from PND-3 into PND-4 and the speed of the heating steam in the tube space of PND-3 and eliminate the occurrence of hydraulic shocks and damages of the heat exchanger tubes.

  7. Steam drum level dynamics in a multiple loop natural circulation system of a pressure-tube type boiling water reactor

    International Nuclear Information System (INIS)

    Jain, Vikas; Kulkarni, P.P.; Nayak, A.K.; Vijayan, P.K.; Saha, D.; Sinha, R.K.

    2011-01-01

    Highlights: → We have highlighted the problem of drum level dynamics in a multiple loop type NC system using RELAP5 code. → The need of interconnections in steam and liquid spaces close to drum is established. → The steam space interconnections equalize pressure and liquid space interconnections equalize level. → With this scheme, the system can withstand anomalous conditions. → However, the controller is found to be inevitable for inventory balance. - Abstract: Advanced Heavy Water Reactor (AHWR) is a pressure tube type boiling water reactor employing natural circulation as the mode of heat removal under all the operating conditions. Main heat transport system (MHTS) of AHWR is essentially a multi-loop natural circulation system with all the loops connected to each other. Each loop of MHTS has a steam drum that provides for gravity based steam-water separation. Steam drum level is a very critical parameter especially in multi-loop natural circulation systems as large departures from the set point may lead to ineffective separation of steam-water or may affect the driving head. However, such a system is susceptible to steam drum level anomalies under postulated asymmetrical operating conditions among the different quadrants of the core like feedwater flow distribution anomaly among the steam drums or power anomaly among the core quadrants. Analyses were carried out to probe such scenarios and unravel the underlying dynamics of steam drum level using system code RELAP5/Mod3.2. In addition, a scheme to obviate such problem in a passive manner without dependence on level controller was examined. It was concluded that steam drums need to be connected in the liquid as well as steam space to make the system tolerant to asymmetrical operating conditions.

  8. Dynamics of tubes in fluid with tube-baffle interaction

    International Nuclear Information System (INIS)

    Chen, S.S.; Jendrzejczyk, J.A.; Wambsganss, M.W.

    1983-09-01

    Three series of tests are performed to evaluate the effects of tube to tube-support-plate (TSP) clearance on tube dynamic characteristics and instability phenomena for tube arrays in crossflow. Test results show that, for relatively large clearances, tubes may possess TSP-inactive modes in which the tubes rattle inside some of the tube-support-plate holes, and that the natural frequencies of TSP-inactive modes are lower than those of TSP-active modes, in which the support plates provide knife-edge type support. Tube response characteristics associated with TSP-inactive modes are sensitive to tube-to-TSP clearance, TSP thickness, excitation amplitude, tube alignment, and the fluid inside the clearance. In addition, tube response is intrinsically nonlinear, with the dominance of TSP-inactive or TSP-active modes depending on the magnitudes of different system parameters. In general, such a system is difficult to model; only a full-scale test can provide all the necessary characteristics. A tube array supported by TSPs with relatively large clearances may be subjected to dynamic instability in some of the TSP-inactive modes; tube response characteristics and impact forces on TSPs for a tube row are studied in detail in this report. Tube displacements associated with the instability of a TSP-inactive mode are small; however, impacts of the tube against TSPs may result in significant damage in a relatively short time. 52 figures

  9. 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)

  10. Design and Computational Fluid Dynamics Optimization of the Tube End Effector for Reactor Pressure Vessel Head Type VVER-1000

    International Nuclear Information System (INIS)

    Novosel, D.

    2006-01-01

    In this paper is presented development and optimization of the tube end effector design which should consist of 4 ultrasonic transducers, 4 Eddy Current's transducers and Radiation Proof Dot Camera. Basically, designing was conducted by main input requests, such as: inner diameter of a tested reactor pressure vessel head penetration tube, dimensions of a transducers and maximum allowable vertical movement of a manipulator connection rod in order to cover all inner tube surface. As is obvious, for ultrasonic testing should be provided the thin layer of liquid material (in our case water was chosen) which is necessary to make physical contact between transducer surface and investigated inner tube surface. By help of Computational Fluid Dynamics, determined were parameters of geometry, as the most important factor of transducer housing, hydraulically parameters for water supply and primary drain together implemented into this housing, movement of the end effectors (vertical and cylindrical) and finally, necessary equipment which has to provide all hydraulically and pneumatic requirements. As the cylindrical surface of the inner tube diameter was liquefied and contact between transducer housing and tested tube wasn't ideally covered, water leakage could occur in downstream direction. To reduce water leakage, which is highly contaminated, developed was second water drain by diffuser assembly which is driven by Venturi pipe, commercially called vacuum generator. Using the Computational Fluid Dynamic, obtained was optimized geometry of diffuser control volume with the highest efficiency, in other words, unobstructed fluid flux. Afterwards, the end effectors system was synchronized to the existing operable system for NDT methods all invented and designed by INETEC. (author)

  11. CFD modeling and experimental verification of oscillating flow and heat transfer processes in the micro coaxial Stirling-type pulse tube cryocooler operating at 90-170 Hz

    Science.gov (United States)

    Zhao, Yibo; Yu, Guorui; Tan, Jun; Mao, Xiaochen; Li, Jiaqi; Zha, Rui; Li, Ning; Dang, Haizheng

    2018-03-01

    This paper presents the CFD modeling and experimental verifications of oscillating flow and heat transfer processes in the micro coaxial Stirling-type pulse tube cryocooler (MCSPTC) operating at 90-170 Hz. It uses neither double-inlet nor multi-bypass while the inertance tube with a gas reservoir becomes the only phase-shifter. The effects of the frequency on flow and heat transfer processes in the pulse tube are investigated, which indicates that a low enough frequency would lead to a strong mixing between warm and cold fluids, thereby significantly deteriorating the cooling performance, whereas a high enough frequency would produce the downward sloping streams flowing from the warm end to the axis and almost puncturing the gas displacer from the warm end, thereby creating larger temperature gradients in radial directions and thus undermining the cooling performance. The influence of the pulse tube length on the temperature and velocity when the frequencies are much higher than the optimal one are also discussed. A MCSPTC with an overall mass of 1.1 kg is worked out and tested. With an input electric power of 59 W and operating at 144 Hz, it achieves a no-load temperature of 61.4 K and a cooling capacity of 1.0 W at 77 K. The changing tendencies of tested results are in good agreement with the simulations. The above studies will help to thoroughly understand the underlying mechanism of the inertance MCSPTC operating at very high frequencies.

  12. Multi-objective parametric optimization of Inertance type pulse tube refrigerator using response surface methodology and non-dominated sorting genetic algorithm

    Science.gov (United States)

    Rout, Sachindra K.; Choudhury, Balaji K.; Sahoo, Ranjit K.; Sarangi, Sunil K.

    2014-07-01

    The modeling and optimization of a Pulse Tube Refrigerator is a complicated task, due to its complexity of geometry and nature. The aim of the present work is to optimize the dimensions of pulse tube and regenerator for an Inertance-Type Pulse Tube Refrigerator (ITPTR) by using Response Surface Methodology (RSM) and Non-Sorted Genetic Algorithm II (NSGA II). The Box-Behnken design of the response surface methodology is used in an experimental matrix, with four factors and two levels. The diameter and length of the pulse tube and regenerator are chosen as the design variables where the rest of the dimensions and operating conditions of the ITPTR are constant. The required output responses are the cold head temperature (Tcold) and compressor input power (Wcomp). Computational fluid dynamics (CFD) have been used to model and solve the ITPTR. The CFD results agreed well with those of the previously published paper. Also using the results from the 1-D simulation, RSM is conducted to analyse the effect of the independent variables on the responses. To check the accuracy of the model, the analysis of variance (ANOVA) method has been used. Based on the proposed mathematical RSM models a multi-objective optimization study, using the Non-sorted genetic algorithm II (NSGA-II) has been performed to optimize the responses.

  13. Superparamagnetic iron oxide nanoparticle attachment on array of micro test tubes and microbeakers formed on p-type silicon substrate for biosensor applications

    Directory of Open Access Journals (Sweden)

    Raja Sufi

    2011-01-01

    Full Text Available Abstract A uniformly distributed array of micro test tubes and microbeakers is formed on a p-type silicon substrate with tunable cross-section and distance of separation by anodic etching of the silicon wafer in N, N-dimethylformamide and hydrofluoric acid, which essentially leads to the formation of macroporous silicon templates. A reasonable control over the dimensions of the structures could be achieved by tailoring the formation parameters, primarily the wafer resistivity. For a micro test tube, the cross-section (i.e., the pore size as well as the distance of separation between two adjacent test tubes (i.e., inter-pore distance is typically approximately 1 μm, whereas, for a microbeaker the pore size exceeds 1.5 μm and the inter-pore distance could be less than 100 nm. We successfully synthesized superparamagnetic iron oxide nanoparticles (SPIONs, with average particle size approximately 20 nm and attached them on the porous silicon chip surface as well as on the pore walls. Such SPION-coated arrays of micro test tubes and microbeakers are potential candidates for biosensors because of the biocompatibility of both silicon and SPIONs. As acquisition of data via microarray is an essential attribute of high throughput bio-sensing, the proposed nanostructured array may be a promising step in this direction.

  14. High-power stirling-type pulse tube cooler for power engineering applications of high temperature superconductivity

    International Nuclear Information System (INIS)

    Dietrich, Marc

    2015-12-01

    For the cooling of high temperature superconducting 4 MVA machines (motors or generators), a single-stage Stirling-type pulse-tube cryocooler was built. The cooling power, which the cryocooler was aimed for, is 80 - 100 W at 30 K with an electrical input power of 10 kW (8 kW pV-power). The advantages of this cooler type compared to traditional cooling concepts are an increased reliability and long maintenance intervals. While single-stage Stirling-type pulse-tube cryocoolers for the temperature range of liquid nitrogen (77 K) are already commercially available, there exist currently no commercial systems for the temperature range near 30 K, which is the important range for applications of high-temperature superconductivity. The experimental setup consisted of a 10 kW linear compressor, type 2S297W, from CFIC Inc. which was used as the pressure wave generator. The compressor was operated by a Micromaster 440 frequency inverter from Siemens, which was controlled by a custom-made computer program. The cold head was made in inline configuration, in order to avoid deflection losses. During the first cool-downs tests a temperature inhomogeneity occurred in the regenerator at low temperature and high pV-power, which was attributed to a constant mass flow (circular dc-flow) within the regenerator. This firstly observed dc-flow, generates a net energy flow from the hot end to the cold end of the regenerator, which reduces the cooling capacity considerably and hence the minimum attainable temperature is severely increased. For the design and optimization of the cold-head, a cryocooler model was initially created using the commercial simulation software Sage, which did not include the regenerator inhomogeneity seen in the experiment. For the modeling of the observed streaming inhomogeneity caused by the dc-flow, the regenerator was replaced by two identical parallel regenerators with variable transverse thermal coupling. In the inhomogeneous case (without dc-flow) the

  15. Microstructure and mechanical characteristics of laser coating-texturing alloying dimples

    International Nuclear Information System (INIS)

    Wan Daping; Chen Bingkui; Shao Yimin; Wang Shilong; Hu Dejin

    2008-01-01

    A novel laser coating-texturing (LCT) technique was proposed to achieve appropriate surface topographies and frictional behaviour. The LCT process was realized by applying laser pulses at very high repetition rate to produce innumerable micro-craters with required shape profile on the surface of the workpiece. Moreover, surface alloying of the dimples was carried out by melting submicron WC-TiC-Co alloy powder on the substrates. Morphology and microstructures of the texturing layers were characterised using optical microscopy (OM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). Mechanical properties of the textured samples were evaluated by abrasive resistance tests and microhardness measurement. Experimental results show that good fusion bonding between the texturing layers and the substrate has been formed, and the texturing layers are mainly composed of dense and hard fine-grained structures. The abrasive wear resistance of the laser coating-textured surface was 10 times higher than that of the substrates. The average surface microhardness values were as high as 830 HV.

  16. Experimental investigation of the performance of an elbow-bend type heat exchanger with a water tube bank used as a heater or cooler in alpha-type Stirling machines

    Energy Technology Data Exchange (ETDEWEB)

    El-Ehwany, A.A.; Hennes, G.M. [Mech. Power Dept., Faculty of Eng., Ain Shams University, Cairo (Egypt); Eid, E.I. [Mech. Dept., Faculty of Ind. Education, Suez Canal University, Suez 43515 (Egypt); El-Kenany, E. [The Specialized Studies Academy, Workers University, Tech. Dept., Mansura (Egypt)

    2011-02-15

    In this work the effect of the elbow-bend geometry and the effect of the tube arrangement on the performance of air-to-water heat exchanger is studied experimentally. In elbow-bend heat exchanger, the direction of the working fluid is bended at 90 degrees to its inlet direction. The heating or cooling fluid flows inside straight tubes while the working fluid flows past the tubes along an elbow pass. Three different types of the geometry of the elbow with three different tube bank arrangements were studied. The results were plotted and analyzed to clarify the effects of the elbow-bend geometry, the tube bank arrangements and the dead volume in the heat exchanger on the heat transfer and pressure drop. Two empirical correlations were deduced for each design, one to predict the relation between Nusselt and Reynolds numbers, while the other relation is between the friction factor and Reynolds number. This work was done to select the more suitable design to be used as a heater or a cooler in Stirling machines. (author)

  17. Comparative transcriptome analysis links distinct peritoneal tumor spread types, miliary and non-miliary, with putative origin, tubes and ovaries, in high grade serous ovarian cancer.

    Science.gov (United States)

    Auer, Katharina; Bachmayr-Heyda, Anna; Aust, Stefanie; Grunt, Thomas W; Pils, Dietmar

    2017-03-01

    High grade serous ovarian cancer (HGSOC) is characterized by extensive local, i.e. peritoneal, tumor spread, manifested in two different clinical presentations, miliary (many millet sized peritoneal implants) and non-miliary (few large exophytically growing peritoneal nodes), and an overall unfavorable outcome. HGSOC is thought to arise from fallopian tube secretory epithelial cells, via so called serous tubal intraepithelial carcinomas (STICs) but an ovarian origin was never ruled out for at least some cases. Comparative transcriptome analyses of isolated tumor cells from fresh HGSOC tissues and (immortalized) ovarian surface epithelial and fallopian tube secretory epithelial cell lines revealed a close relation between putative origin and tumor spread characteristic, i.e. miliary from tubes and non-miliary from ovaries. The latter were characterized by more mesenchymal cell characteristics, more adaptive tumor immune infiltration, and a favorable overall survival. Several molecular sub-classification systems (Crijns' overall survival signature, Yoshihara's subclasses, and a collagen-remodeling signature) seem to already indicate origin. Putative origin alone is a significant independent predictor for HGSOC outcome, validated in independent patient cohorts. Characteristics of both spread types could guide development of new targeted therapeutics, which are urgently needed. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. 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,

  19. Influence of Different Types of Obstacles on the Propagation of Premixed Methane-Air Flames in a Half-Open Tube

    Directory of Open Access Journals (Sweden)

    Quan Wang

    2017-11-01

    Full Text Available To understand the propagation characteristics of methane-air deflagration flames and in an obstacle-filled tube, a high-speed color video camera, photoelectric sensors, and pressure transducers were used to test the deflagration flame propagating parameters. The tests were run in a 1500 mm long plexiglass tube with a 100 × 100 mm square cross-section. The obstacles included four types of repeated baffles and five forms of solid structure obstacles. The results showed that: (1 the flame front was constantly distorted, stretched, and deformed by different types of obstacles and, consequently, the flame propagating parameters increased; (2 plates and triple prisms increased the speed of the flame and overpressure to the highest extent, whereas cuboids and quadrangulars exerted an intermediate effect. However, the effect of cylindrical obstacles was comparatively limited. It was suggested that the obstacle’s surface edge mutation or curvature changes were the main factors stimulating the flame acceleration; (3 the peak pressure of deflagration was relatively low near the ignition end, increased gradually until it reached the maximum at the middle of the tube, and decreased rapidly near the open end; and (4 the fixed obstacles in front of the flame exhibited a blocking effect on flame propagation during the initial stages; the flame speed and overpressure increased when the flame came into contact with the obstacles. This study is of significance because it explains the methane-air propagation mechanism induced by different types of obstacles. The findings have value for preventing or controlling gas explosion disasters.

  20. CRL X-ray tube

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  1. CRL X-RAY TUBE

    OpenAIRE

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

    2015-01-01

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

  2. Mineral Grains, Dimples, and Hot Volcanic Organic Streams: Dynamic Geological Backstage of Macromolecular Evolution.

    Science.gov (United States)

    Skoblikow, Nikolai E; Zimin, Andrei A

    2018-03-28

    The hypothesis of hot volcanic organic stream as the most probable and geologically plausible environment for abiogenic polycondensation is proposed. The primary synthesis of organic compounds is considered as result of an explosive volcanic (perhaps, meteorite-induced) eruption. The eruption was accompanied by a shock wave propagating in the primeval atmosphere and resulting in the formation of hot cloud of simple organic compounds-aldehydes, alcohols, amines, amino alcohols, nitriles, and amino acids-products, which are usually obtained under the artificial conditions in the spark-discharge experiments. The subsequent cooling of the organic cloud resulted in a gradual condensation and a serial precipitation of organic compounds (in order of decreasing boiling point values) into the liquid phase forming a hot, viscous and muddy organic stream (named "lithorheos"). That stream-even if the time of its existence was short-is considered here as a geologically plausible environment for abiogenic polycondensation. The substances successively prevailing in such a stream were cyanamide, acetamide, formamide, glycolonitrile, acetonitrile. An important role was played by mineral (especially, phosphate-containing) grains (named "lithosomes"), whose surface was modified with heterocyclic nitrogen compounds synthesized in the course of eruption. When such grains got into hot organic streams, their surface catalytic centers (named "lithozymes") played a decisive role in the emergence, facilitation and maintenance of prebiotic reactions and key processes characteristic of living systems. Owing to its cascade structure, the stream was a factor underlying the formation of mineral-polymeric aggregates (named "lithocytes") in the small natural streambed cavities (dimples)-as well as a factor of their further spread within larger geological locations which played a role of chemo-ecological niches. All three main stages of prebiotic evolution (primary organic synthesis

  3. Research on the internal pressure behavior of metal gas distribution pipelines with different types of tubing defects

    Directory of Open Access Journals (Sweden)

    Filip Stefan Mihai

    2017-01-01

    Full Text Available The paper aims to approach an important subject related to natural gas distribution networks which, depending on the expansion of the localities, are composed of intercommunicating pipes, pressure reducing stations and branch connections fittings. The urban networks are the most complex ones and the rural areas networks are the simplest. However, irrespective of their installation, they must meet the safety operating requirements as much as possible. According to standards, all these components must be tight and pressure resistant. In this regard, we intend to approach a very important issue related to the behavior of the tubular steel material showing corrosion and/or material defects, and to the internal stress caused by the gas pressure on the walls of the tubing material.

  4. Efficient charge separation based on type-II g-C3N4/TiO2-B nanowire/tube heterostructure photocatalysts.

    Science.gov (United States)

    Chen, Hongmei; Xie, Yinghao; Sun, Xiaoqin; Lv, Meilin; Wu, Fangfang; Zhang, Lei; Li, Li; Xu, Xiaoxiang

    2015-08-07

    Separation of photo-generated charges has played a crucial role in controlling the actual performance of a photocatalytic system. Here we have successfully fabricated g-C3N4/TiO2-B nanowire/tube heterostructures through facile urea degradation reactions. Owing to the effective separation of photo-generated charges associated with the type-II band alignment and intimate interfacial contacts between g-C3N4 and TiO2-B nanowires/tubes, such heterostructures demonstrate an improved photocatalytic activity over individual moieties. Synthetic conditions such as hydrothermal temperatures for the preparation of TiO2-B and the weight ratio of TiO2-B to urea were systematically investigated. A high crystallinity of TiO2-B as well as the proper growth of g-C3N4 on its surface are critical factors for a better performance. Our simple synthetic method and the prolonged lifetime of photo-generated charges signify the importance of type-II heterostructures in the photocatalytic applications.

  5. The effect of dimple error on the horizontal launch angle and side spin of the golf ball during putting.

    Science.gov (United States)

    Richardson, Ashley K; Mitchell, Andrew C S; Hughes, Gerwyn

    2017-02-01

    This study aimed to examine the effect of the impact point on the golf ball on the horizontal launch angle and side spin during putting with a mechanical putting arm and human participants. Putts of 3.2 m were completed with a mechanical putting arm (four putter-ball combinations, total of 160 trials) and human participants (two putter-ball combinations, total of 337 trials). The centre of the dimple pattern (centroid) was located and the following variables were measured: distance and angle of the impact point from the centroid and surface area of the impact zone. Multiple regression analysis was conducted to identify whether impact variables had significant associations with ball roll variables, horizontal launch angle and side spin. Significant associations were identified between impact variables and horizontal launch angle with the mechanical putting arm but this was not replicated with human participants. The variability caused by "dimple error" was minimal with the mechanical putting arm and not evident with human participants. Differences between the mechanical putting arm and human participants may be due to the way impulse is imparted on the ball. Therefore it is concluded that variability of impact point on the golf ball has a minimal effect on putting performance.

  6. Comparative Neutronics Analysis of DIMPLE S06 Criticality Benchmark with Contemporary Reactor Core Analysis Computer Code Systems

    Directory of Open Access Journals (Sweden)

    Wonkyeong Kim

    2015-01-01

    Full Text Available A high-leakage core has been known to be a challenging problem not only for a two-step homogenization approach but also for a direct heterogeneous approach. In this paper the DIMPLE S06 core, which is a small high-leakage core, has been analyzed by a direct heterogeneous modeling approach and by a two-step homogenization modeling approach, using contemporary code systems developed for reactor core analysis. The focus of this work is a comprehensive comparative analysis of the conventional approaches and codes with a small core design, DIMPLE S06 critical experiment. The calculation procedure for the two approaches is explicitly presented in this paper. Comprehensive comparative analysis is performed by neutronics parameters: multiplication factor and assembly power distribution. Comparison of two-group homogenized cross sections from each lattice physics codes shows that the generated transport cross section has significant difference according to the transport approximation to treat anisotropic scattering effect. The necessity of the ADF to correct the discontinuity at the assembly interfaces is clearly presented by the flux distributions and the result of two-step approach. Finally, the two approaches show consistent results for all codes, while the comparison with the reference generated by MCNP shows significant error except for another Monte Carlo code, SERPENT2.

  7. Determination of eustachius tube ventilation functioning among benign type chronic suppurative otitis media and non-otitis media subjects using sonotubometry

    Science.gov (United States)

    Ikhwan, M.; Hafil, A. F.; Bramanthyo, B.

    2017-08-01

    The Eustachian tube (ET) is responsible for the ventilation, protection, and cleaning of the middle ear. ET dysfunction plays an important role in the pathogenesis of otitis media cases, and thus the treatment and prognosis of these cases is extremely dependent on adequate ET function, which can ultimately affect the success rate of middle ear reconstruction practices. Data research on the ET’s ventilation function is needed to ensure the success of therapy and surgery treatments in the case of Chronic Suppurative Otitis Media (CSOM) patients. This study aims to investigate ET ventilation functioning in benign type CSOM and non-otitis media subjects and to develop another modality to measure ET ventilation functioning in patients with intact and perforated tympanic membranes. A comparative cross-sectional study of 36 benign type CSOM patients and 80 non-otitis media subjects will be conducted using sonotubometry and the rated parameter measurements of ET opening frequency, amplitude and ET opening duration. Malfunctioning ventilation of the ET is more common among benign type CSOM subjects (47%) than among non-otitis media subjects (18.75%). There is a significant difference (p = 0.002) between the ET ventilation functioning of benign type CSOM subjects and non-otitis media subjects—benign type CSOM subjects have rates of malfunctioning ET ventilation that are 3.88 times higher than those of non-otitis media subjects. Patients with benign type CSOM are more likely to experience malfunctioning ET ventilation than are non-otitis media subjects.

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

    Science.gov (United States)

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

    2017-12-25

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

  9. Biomineralization and biosignatures of coralloid-type speleothems from lava tubes of Galapagos Islands: evidences on the fossil record of prokaryotes

    Science.gov (United States)

    Miller, Ana Z.; Garcia-Sanchez, Angela M.; Pereira, Manuel F. C.; Gazquez, Fernando; Calaforra, José M.; Forti, Paolo; Toulkeridis, Theofilos; Martínez-Frías, Jesús; Saiz-Jimenez, Cesareo

    2016-04-01

    Lava tubes have traditionally been considered of little interest from a mineralogical point of view. Recently, this type of volcanic caves has received particular attention because lava tubes have been described on Mars. Speleothems, or secondary mineral deposits in lava tubes are mainly composed of siliceous minerals. Coralloid-type speleothems are found either on basaltic cave walls or on the surface of other speleothems. Several authors attribute a microbially mediated origin to their formation. This type of speleothems was recorded within Royal Palm Cave of Santa Cruz Island in Galapagos Archipelago (Ecuador), a lava tube 600 m long, 5 to 15 m height and 2 to 10 m width. The Galapagos Islands are an archipelago of 19 volcanic islands located some 1500 km west of Ecuador, in the Pacific Ocean. These islands host one of the most biodiverse settings on Earth, studied by Charles Darwin. Beige and greyish small coralloids were collected in Royal Palm Cave and analysed by field emission scanning electron microscopy with energy dispersive X-ray spectroscopy (FESEM-EDS), X-ray micro-computed tomography (micro-CT) and mineralogical analyses for morphological, 3D microstructural and compositional characterization, as well as for assessing microbe-mineral interactions and biogenicity. In addition, 16S rRNA gene analyses were performed to identify microbial communities associated with the coralloid-type speleothems. The coralloids showed internal compositional zonation along the growth direction of the speleothems, according to micro-CT data. Internal layering was clearly discernable by the differences in opacity of the distinct mineralogical phases to X-rays, being dominated by alteration products of siliceous composition, whereas more opaque phases, usually Ca-rich minerals, were dominant in the outermost part of the speleothems. X-ray diffraction and infrared spectroscopy reinforced that the first stage of deposition is mainly composed of opal A and clay minerals

  10. Acute complications associated with bedside placement of feeding tubes.

    Science.gov (United States)

    Baskin, William N

    2006-02-01

    Several types of feeding tubes can be placed at a patient's bedside; examples include nasogastric, nasointestinal, gastrostomy, and jejunostomy tubes. Nasoenteral tubes can be placed blindly at bedside or with the assistance of placement devices. Nasoenteric tubes can also be placed via fluoroscopy and endoscopy. Gastrostomy and jejunostomy tubes can be placed using endoscopic techniques. This paper will describe the indications and contraindications for different types of tubes that can be placed at the bedside and complications associated with tube placement. Complications associated with nasoenteral tubes include inadvertent malpositioning of the tube, epistaxis, sinusitis, inadvertent tube removal, tube clogging, tube-feeding-associated diarrhea, and aspiration pneumonia. Complications from percutaneous gastrostomy and jejunostomy tube placements include procedure-related mishaps, site infection, leakage, buried bumper syndrome, tube malfunction, and inadvertent removal. These complications will be reviewed, along with a discussion of incidence, cause, treatment, and prevention approaches.

  11. Conceptual design of a passive moderator cooling system for a pressure tube type natural circulation boiling water cooled reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Mukesh [Reactor Engineering Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Pal, Eshita, E-mail: eshi.pal@gmail.com [Homi Bhabha National Institute, Anushaktinagar, Mumbai 400 094 (India); Nayak, Arun K.; Vijayan, Pallipattu K. [Reactor Engineering Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

    2015-09-15

    Highlights: • Passive moderator cooling system is designed to cool moderator passively during SBO. • PMCS is a system of two natural circulation loops, coupled via a heat exchanger. • RELAP5 analyses show that PMCS maintains moderator within safe limits for 7 days. - Abstract: The recent Fukushima accident has raised strong concern and apprehensions about the safety of reactors in case of a prolonged Station Black Out (SBO) continuing for several days. In view of this, a detailed study was performed simulating this condition in Advanced Heavy Water Reactor. In this study, a novel concept of moderator cooling by passive means has been introduced in the reactor design. The Passive Moderator Cooling System (PMCS) consists of a shell and tube heat exchanger designed to remove 2 MW heat from the moderator inside Calandria. The heat exchanger is located at a suitable elevation from the Calandria of the reactor, such that the hot moderator rises due to buoyancy into the heat exchanger and upon cooling from shell side water returns to Calandria forming a natural circulation loop. The shell side of the heat exchanger is also a natural circulation loop connected to an overhead large water reservoir, namely the GDWP. The objective of the PMCS is to remove the heat from the moderator in case of an SBO and maintaining its temperature below the permissible safe limit (100 °C) for at least 7 days. The paper first describes the concept of the PMCS. The concept has been assessed considering a prolonged SBO for at least 7 days, through an integrated analysis performed using the code RELAP5/MOD3.2 considering all the major components of the reactor. The analysis shows that the PMCS is able to maintain the moderator temperature below boiling conditions for 7 days.

  12. SU-G-IeP2-05: Effect of Localizer Type and Patient Off-Centering On CT Radiation Dose with Use of Automatic Tube Current Modulation

    International Nuclear Information System (INIS)

    Ruan, C; Sodickson, A; Hamberg, L

    2016-01-01

    Purpose: Apparent patient size in CT localizers varies with localizer type and patient positioning, resulting in variation in effective mAs as guided by Tube Current Modulation (TCM). Our aim was to investigate the effects of vertical off-centering on CTDI-vol when using different localizer types and TCM strengths. Methods: A CTDI body phantom was scanned using an abdominal protocol with three TCM strengths (Siemens Definition AS40, CAREDose4D; very weak, average, very strong). Data was acquired at 11 table height positions; with phantom center at isocenter and at 10 other positions between 142mm below and 53mm above. At each position, scans were acquired using 5 different localizer types: PA, AP, Lateral, PA+Lateral, and Lateral+PA. CTDI-vol was recorded for the 165 combinations of table height, localizer type, and TCM strength, and magnification factors measured from localizer images. Results: Magnification factors from AP and PA localizers ranged from 0.79–1.11 and 1.35–0.91, respectively from lowest to highest positions (highest with phantom located closest to X-ray tube), with a smaller impact when using Lateral, PA+Lateral, Lateral+PA localizer types, all of which behaved similarly. For an average TCM strength and PA localizer, CTDI-vol ranged from 75% higher to 12% lower than the isocenter value for the lowest to highest table positions, respectively. For table positions ranging from lowest to highest, CTDI-vol ranged from −23% to 17% for AP, from −8% to 0.3% for lateral and from −7% to 1% for a combination of PA and Lateral in either order. Similar behavior was found for different TCM strengths, but effects were more pronounced for very strong compared with very weak modulation strengths. Conclusion: Patient off-centering substantially impacts radiation dose, which depends on the amount of vertical offcentering and type of the localizer used. The combination of PA and Lateral localizers is most robust against effects of patient off-centering.

  13. SU-G-IeP2-05: Effect of Localizer Type and Patient Off-Centering On CT Radiation Dose with Use of Automatic Tube Current Modulation

    Energy Technology Data Exchange (ETDEWEB)

    Ruan, C; Sodickson, A; Hamberg, L [Brigham and Women’s Hospital, Boston, MA (United States)

    2016-06-15

    Purpose: Apparent patient size in CT localizers varies with localizer type and patient positioning, resulting in variation in effective mAs as guided by Tube Current Modulation (TCM). Our aim was to investigate the effects of vertical off-centering on CTDI-vol when using different localizer types and TCM strengths. Methods: A CTDI body phantom was scanned using an abdominal protocol with three TCM strengths (Siemens Definition AS40, CAREDose4D; very weak, average, very strong). Data was acquired at 11 table height positions; with phantom center at isocenter and at 10 other positions between 142mm below and 53mm above. At each position, scans were acquired using 5 different localizer types: PA, AP, Lateral, PA+Lateral, and Lateral+PA. CTDI-vol was recorded for the 165 combinations of table height, localizer type, and TCM strength, and magnification factors measured from localizer images. Results: Magnification factors from AP and PA localizers ranged from 0.79–1.11 and 1.35–0.91, respectively from lowest to highest positions (highest with phantom located closest to X-ray tube), with a smaller impact when using Lateral, PA+Lateral, Lateral+PA localizer types, all of which behaved similarly. For an average TCM strength and PA localizer, CTDI-vol ranged from 75% higher to 12% lower than the isocenter value for the lowest to highest table positions, respectively. For table positions ranging from lowest to highest, CTDI-vol ranged from −23% to 17% for AP, from −8% to 0.3% for lateral and from −7% to 1% for a combination of PA and Lateral in either order. Similar behavior was found for different TCM strengths, but effects were more pronounced for very strong compared with very weak modulation strengths. Conclusion: Patient off-centering substantially impacts radiation dose, which depends on the amount of vertical offcentering and type of the localizer used. The combination of PA and Lateral localizers is most robust against effects of patient off-centering.

  14. Fuel composition optimization in a 78-element fuel bundle for use in a pressure tube type supercritical water-cooled reactor

    International Nuclear Information System (INIS)

    Hummel, D.W.; Novog, D.R.

    2012-01-01

    A 78-element fuel bundle containing a plutonium-thorium fuel mixture has been proposed for a Generation IV pressure tube type supercritical water-cooled reactor. In this work, using a lattice cell model created with the code DRAGON,the lattice pitch, fuel composition (fraction of PuO 2 in ThO 2 ) and radial enrichment profile of the 78-element bundle is optimized using a merit function and a metaheuristic search algorithm.The merit function is designed such that the optimal fuel maximizes fuel utilization while minimizing peak element ratings and coolant void reactivity. A radial enrichment profile of 10 wt%, 11 wt% and 20 wt% PuO 2 (inner to outer ring) with a lattice pitch of 25.0 cm was found to provide the optimal merit score based on the aforementioned criteria. (author)

  15. Fuel composition optimization in a 78-element fuel bundle for use in a pressure tube type supercritical water-cooled reactor

    Energy Technology Data Exchange (ETDEWEB)

    Hummel, D.W.; Novog, D.R. [McMaster Univ., Hamilton, Ontario (Canada)

    2012-07-01

    A 78-element fuel bundle containing a plutonium-thorium fuel mixture has been proposed for a Generation IV pressure tube type supercritical water-cooled reactor. In this work, using a lattice cell model created with the code DRAGON,the lattice pitch, fuel composition (fraction of PuO{sub 2} in ThO{sub 2}) and radial enrichment profile of the 78-element bundle is optimized using a merit function and a metaheuristic search algorithm.The merit function is designed such that the optimal fuel maximizes fuel utilization while minimizing peak element ratings and coolant void reactivity. A radial enrichment profile of 10 wt%, 11 wt% and 20 wt% PuO{sub 2} (inner to outer ring) with a lattice pitch of 25.0 cm was found to provide the optimal merit score based on the aforementioned criteria. (author)

  16. Comparative study between the Phramongkutklao's diabetic blenderized diets and commercial diabetic diets on glycemic variability in continuous tube fed patients with type 2 diabetes.

    Science.gov (United States)

    Tiyapanjanit, Teeranun; Boonyavarakul, Apussanee

    2014-11-01

    Rapid glucose fluctuations over daily period play an important role on diabetic complications. To compare glycemic variability, mean plasma glucose, number ofcapillary blood glucose tests, and cost between the Phramongkutklao's diabetic formula and commercial diabetic formula in continuous tube fed patients with stable condition in type 2 diabetes. A cross-over design study was performed between October 2010 and February 2011 in the medical department in Phramongkutklao Hospital. The researchers enrolled type 2 diabetic patients with stable condition who were on continuous tube fed. Seventy-two-hour continuous subcutaneous glucose monitoring was performed in all patients. Comparison ofmean amplitude ofglycemic excursions (MAGE), mean plasma glucose, cost, and number of capillary blood glucose tests were analyzed by using non-parametric Wilcoxon signed-rank test. Significance was defined as pDiabetic Formula resulted in significantly lower mean plasma glucose (122±26.25 vs. 144.68±36.91 mg/dL, p = 0.022), cost (550.1±33.57 vs. 797.81±42.29 baht, p = 0.004), and number of capillary blood glucose tests (5±0.94 vs. 5.3±0.82 times, p = 0.083) when compared with commercial diabetic formula, but no significant difference in MAGE level (5.86±2.78 vs. 7.71±4.34 mg/dL, p = 0.333). The Phramongkutklao's diabetic formula has significantly lower mean plasma glucose, less number of capillary blood glucose tests, and is less expensive than commercial diabetic formula. The glucose variability (MAGE) of the Phramongkutklao diabetic formula has also less than commercial diabetic formula, but does not reach statistical significance. The level ofplasma glucose was lower than 180 mg/dL in both formulas.

  17. Characterization of tube support alloys

    International Nuclear Information System (INIS)

    Vaia, A.R.

    1985-01-01

    The involvement and relationship of carbon steel corrosion products in the tube denting phenomenon promoted an intensive research effort to: 1) understand, reproduce, and arrest the denting process, and 2) evaluate alternative tube support materials to provide additional corrosion resistance. The paper summarizes a corrosion testing program for the verification of type 405 stainless steel under acid or all volatile treatment conditions

  18. Numerical and experimental study of an annular pulse tube used in the pulse tube cooler

    Science.gov (United States)

    Pang, Xiaomin; Chen, Yanyan; Wang, Xiaotao; Dai, Wei; Luo, Ercang

    2017-12-01

    Multi-stage pulse tube coolers normally use a U-type configuration. For compactness, it is attractive to build a completely co-axial multi-stage pulse tube cooler. In this way, an annular shape pulse tube is inevitable. Although there are a few reports about previous annular pulse tubes, a detailed study and comparison with a circular pulse tube is lacking. In this paper, a numeric model based on CFD software is carried out to compare the annular pulse tube and circular pulse tube used in a single stage in-line type pulse tube cooler with about 10 W of cooling power at 77 K. The length and cross sectional area of the two pulse tubes are kept the same. Simulation results show that the enthalpy flow in the annular pulse tube is lower by 1.6 W (about 11% of the enthalpy flow) compared to that in circular pulse tube. Flow and temperature distribution characteristics are also analyzed in detail. Experiments are then conducted for comparison with an in-line type pulse tube cooler. With the same acoustic power input, the pulse tube cooler with a circular pulse tube obtains 7.88 W of cooling power at 77 K, while using an annular pulse tube leads to a cooling power of 7.01 W, a decrease of 0.9 W (11.4%) on the cooling performance. The study sets the basis for building a completely co-axial two-stage pulse tube cooler.

  19. Ear Tubes

    Science.gov (United States)

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

  20. Dimpled/grooved face on a fuel injection nozzle body for flame stabilization and related method

    Science.gov (United States)

    Uhm, Jong Ho; Johnson, Thomas Edward; Kim, Kwanwoo; Zuo, Baifang

    2013-08-20

    A fuel injection head for a fuel nozzle used in a gas turbine combustor includes a substantially hollow body formed with an upstream end face, a downstream end face and a peripheral wall extending therebetween. A plurality of pre-mix tubes or passages extend axially through the hollow body with inlets at the upstream end face and outlets at the downstream end face. An exterior surface of the downstream end face is formed with three-dimensional surface features that increase a total surface area of the exterior surface as compared to a substantially flat, planar downstream end face.

  1. Neutron tubes

    Science.gov (United States)

    Leung, Ka-Ngo [Hercules, CA; Lou, Tak Pui [Berkeley, CA; Reijonen, Jani [Oakland, CA

    2008-03-11

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

  2. Failure analysis of boiler tube

    International Nuclear Information System (INIS)

    Mehmood, K.; Siddiqui, A.R.

    2007-01-01

    Boiler tubes are energy conversion components where heat energy is used to convert water into high pressure superheated steam, which is then delivered to a turbine for electric power generation in thermal power plants or to run plant and machineries in a process or manufacturing industry. It was reported that one of the tubes of a fire-tube boiler used in a local industry had leakage after the formation of pits at the external surface of the tube. The inner side of the fire tube was working with hot flue gasses with a pressure of 10 Kg/cm/sup 2/ and temperature 225 degree C. The outside of the tube was surrounded by feed water. The purpose of this study was to determine the cause of pits developed at the external surface of the failed boiler tube sample. In the present work boiler tube samples of steel grade ASTM AI61/ASTM A192 were analyzed using metallographic analysis, chemical analysis, and mechanical testing. It was concluded that the appearance of defects on the boiler tube sample indicates cavitation type corrosion failure. Cavitation damage superficially resembled pitting, but surface appeared considerably rougher and had many closely spaced pits. (author)

  3. 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.

  4. 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.

  5. Effect of Loop Configuration on Steam Drum Level Control for a Multiple Drum Interconnected Loops Pressure Tube Type Boiling Water Reactor

    Science.gov (United States)

    Gaikwad, Avinash J.; Vijayan, P. K.; Iyer, Kannan; Bhartiya, Sharad; Kumar, Rajesh; Lele, H. G.; Ghosh, A. K.; Kushwaha, H. S.; Sinha, R. K.

    2009-12-01

    For AHWR (Advanced Heavy Water Reactor), a pressure tube type Boiling Water Reactor (BWR) with parallel inter-connected loops, the Steam Drum (SD) level control is closely related to Main Heat Transport (MHT) coolant inventory and sustained heat removal through natural circulation, hence overall safety of the power plant. The MHT configuration with multiple (four) interconnected loops influences the SD level control in a manner which has not been previously addressed. The MHT configuration has been chosen based on comprehensive overall design requirements and certain Postulated Initiated Event (PIEs) for Loss of Coolant Accident (LOCA), which postulates a double ended break in the four partitioned Emergency Core Cooling System (ECCS) header. A conventional individual three-element SD level controller can not account for the highly coupled and interacting behaviors, of the four SD levels. An innovative three-element SD level control scheme is proposed to overcome this situation. The response obtained for a variety of unsymmetrical disturbances shows that the SD levels do not diverge and quickly settle to the various new set points assigned. The proposed scheme also leads to enhanced safety margins for most of the PIEs considered with a little influence on the 100% full power steady-state design conditions.

  6. Performance Study of a Cylindrical Parabolic Concentrating Solar Water Heater with Nail Type Twisted Tape Inserts in the Copper Absorber Tube

    Directory of Open Access Journals (Sweden)

    Amit K. Bhakta

    2018-01-01

    Full Text Available This paper reports the overall thermal performance of a cylindrical parabolic concentrating solar water heater (CPCSWH with inserting nail type twisted tape (NTT in the copper absorber tube for the nail twist pitch ratios, 4.787, 6.914 and 9.042, respectively. The experiments are conducted for a constant volumetric water flow rate and during the time period 9:00 a.m. to 15:00 p.m. The useful heat gain, hourly solar energy collected and hourly solar energy stored in this solar water heater were found to be higher for the nail twist pitch ratio 4.787. The above said parameters were found to be at a peak at noon and observed to follow the path of variation of solar intensity. At the start of the experiment, the value of charging efficiency was observed to be maximum, whereas the maximum values of instantaneous efficiency and overall thermal efficiency were observed at noon. The key finding is that the nail twist pitch ratio enhances the overall thermal performance of the CPCSWH.

  7. Advances in single- and multi-stage Stirling-type pulse tube cryocoolers for space applications in NLIP/SITP/CAS

    Science.gov (United States)

    Dang, Haizheng; Tan, Jun; Zha, Rui; Li, Jiaqi; Zhang, Lei; Zhao, Yibo; Gao, Zhiqian; Bao, Dingli; Li, Ning; Zhang, Tao; Zhao, Yongjiang; Zhao, Bangjian

    2017-12-01

    This paper presents a review of recent advances in single- and multi-stage Stirling-type pulse tube cryocoolers (SPTCs) for space applications developed at the National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences (NLIP/SITP/CAS). A variety of single-stage SPTCs operating at 25-150 K have been developed, including several mid-sized ones operating at 80-110 K. Significant progress has been achieved in coolers operating at 30-40 K which use common stainless steel meshes as regenerator matrices. Another important advance is the micro SPTCs with an overall mass of 300-800 g operating at high frequencies varying from 100 Hz to 400 Hz. The main purpose of developing two-stage SPTCs is to simultaneously acquire cooling capacities at both stages, obviating the need for auxiliary precooling in various applications. The three-stage SPTCs are developed mainly for applications at around 10 K, which are also used for precooling the J-T coolers to achieve further lower temperatures. The four-stage SPTCs are developed to directly achieve the liquid helium temperature for cooling space low-Tc superconducting devices and for the deep space exploration as well. Several typical development programs are described and an overview of the cooler performances is presented.

  8. DEVELOPMENT OF AN ANALYTICAL METHOD TO EVALUATE THE INTEGRITY OF A CALANDRIA TUBE IN THE CASE OF PRESSURE TUBE RUPTURE

    OpenAIRE

    森下 善嗣

    1990-01-01

    An analytical method which consists of two‐dimensional thermal‐hydraulic analysis and three‐dimensional structural analysis has been proposed to evaluate the integrity of a calandria tube in the case of pressure tube rupture in a pressure tube type reactor.In order to validate the method,experiments were carried out with coaxially arranged double tubes simulating a pressure tube and a calandria tube.Experimental data were also comparedwith analytical results with the proposed method.

  9. Preliminary design study of removable integral steam generator units of the multiple helically wound tube type for a 1250 MW(th) H.T.G.C. reactor

    International Nuclear Information System (INIS)

    Gilli, P.V.; Fritz, K.; Lippitsch, J.; Sandri, A.H.; Weiss, B.

    1965-11-01

    The possibilities of designing a multiple steam generator for a 1250 MW(th) High Temperature Gas-Cooled Reactor, consisting of 18 units which are able to pass through 5 ft diam. holes in the integral prestressed concrete pressure vessel are investigated. A lay-out and design with bundles of multi-start helical tubes is evolved, particular attention being paid to the questions of tube blanking and removal of the unit, and of selection of materials for superheater and reheater tubes. Thermal and stress calculations have been carried out, using the Waagner-Biro Computer Code ADURHELIX. (author)

  10. Single-Tube Dodecaplex PCR Panel of Polymorphic Microsatellite Markers Closely Linked to theDMPKCTG Repeat for Preimplantation Genetic Diagnosis of Myotonic Dystrophy Type 1.

    Science.gov (United States)

    Lian, Mulias; Zhao, Mingjue; Lee, Caroline G; Chong, Samuel S

    2017-06-01

    Preimplantation genetic diagnosis (PGD) of myotonic dystrophy type 1 (DM1) currently uses conventional PCR to detect nonexpanded dystrophia myotonica protein kinase ( DMPK ) alleles or triplet-primed PCR to detect the CTG-expanded alleles, coupled with analysis of linked microsatellite markers to increase diagnostic accuracy. We aimed to simplify the process of identification and selection of informative linked markers for application to DM1 PGD. An in silico search was performed to identify all markers within 1-1.5 Mb flanking the DMPK gene. Five previously known (D19S559, APOC2, D19S543, D19S112, and BV209569) and 7 novel (DM45050, DM45178, DM45209, DM45958, DM46513, DM46892, and DM47004.1) markers with potentially high heterozygosity values and polymorphism information content were selected and optimized in a single-tube multiplex PCR panel. Analysis of 184 DNA samples of Chinese and Caucasian individuals (91 from unrelated, anonymized cord blood of Chinese babies born at the National University Hospital, Singapore, and 93 Caucasian DNA samples from the Human Variation Panel HD100CAU) confirmed the high polymorphism indices of all markers (polymorphism information content >0.5), with observed heterozygosity values ranging from 0.62-0.93. All individuals were heterozygous for at least 6 markers, with 99.5% of individuals heterozygous for at least 2 markers on either side of the DMPK CTG repeat. The dodecaplex marker assay was successfully validated on 42 single cells and 12 whole genome amplified single cells. The DM1 multiplex PCR panel is suitable for use in DM1 PGD either as a standalone linkage-based assay or as a complement to DMPK CTG repeat expansion-mutation detection. © 2017 American Association for Clinical Chemistry.

  11. 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.

  12. Tracheostomy tube - eating

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000464.htm Tracheostomy tube - eating To use the sharing features on ... when you swallow foods or liquids. Eating and Tracheostomy Tubes When you get your tracheostomy tube, or ...

  13. Eustachian tube patency

    Science.gov (United States)

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

  14. 42 CFR 84.152 - Breathing tube test; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing tube test; minimum requirements. 84.152... Respirators § 84.152 Breathing tube test; minimum requirements. (a)(1) Type A and Type B supplied-air respirators shall employ one or two flexible breathing tubes of the nonkinking type which extend from the...

  15. Flux tubes at finite temperature

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-06-07

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

  16. Heat exchanger tube mounts

    Science.gov (United States)

    Wolowodiuk, W.; Anelli, J.; Dawson, B.E.

    1974-01-01

    A heat exchanger in which tubes are secured to a tube sheet by internal bore welding is described. The tubes may be moved into place in preparation for welding with comparatively little trouble. A number of segmented tube support plates are provided which allow a considerable portion of each of the tubes to be moved laterally after the end thereof has been positioned in preparation for internal bore welding to the tube sheet. (auth)

  17. Tube holding system

    International Nuclear Information System (INIS)

    Cunningham, R.C.

    1978-01-01

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

  18. 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.

  19. High-power stirling-type pulse tube cooler for power engineering applications of high temperature superconductivity; Hochleistungspulsrohrkuehler vom Stirling-Typ fuer energietechnische Anwendungen der Hochtemperatursupraleitung

    Energy Technology Data Exchange (ETDEWEB)

    Dietrich, Marc

    2015-12-15

    For the cooling of high temperature superconducting 4 MVA machines (motors or generators), a single-stage Stirling-type pulse-tube cryocooler was built. The cooling power, which the cryocooler was aimed for, is 80 - 100 W at 30 K with an electrical input power of 10 kW (8 kW pV-power). The advantages of this cooler type compared to traditional cooling concepts are an increased reliability and long maintenance intervals. While single-stage Stirling-type pulse-tube cryocoolers for the temperature range of liquid nitrogen (77 K) are already commercially available, there exist currently no commercial systems for the temperature range near 30 K, which is the important range for applications of high-temperature superconductivity. The experimental setup consisted of a 10 kW linear compressor, type 2S297W, from CFIC Inc. which was used as the pressure wave generator. The compressor was operated by a Micromaster 440 frequency inverter from Siemens, which was controlled by a custom-made computer program. The cold head was made in inline configuration, in order to avoid deflection losses. During the first cool-downs tests a temperature inhomogeneity occurred in the regenerator at low temperature and high pV-power, which was attributed to a constant mass flow (circular dc-flow) within the regenerator. This firstly observed dc-flow, generates a net energy flow from the hot end to the cold end of the regenerator, which reduces the cooling capacity considerably and hence the minimum attainable temperature is severely increased. For the design and optimization of the cold-head, a cryocooler model was initially created using the commercial simulation software Sage, which did not include the regenerator inhomogeneity seen in the experiment. For the modeling of the observed streaming inhomogeneity caused by the dc-flow, the regenerator was replaced by two identical parallel regenerators with variable transverse thermal coupling. In the inhomogeneous case (without dc-flow) the

  20. AN EXPERIMENTAL STUDY FOR HEAT TRANSFER ENHANCEMENT BY LAMINAR FORCED CONVECTION FROM HORIZONTAL AND INCLINED TUBE HEATED WITH CONSTANT HEAT FLUX, USING TWO TYPES OF POROUS MEDIA

    Directory of Open Access Journals (Sweden)

    Thamir K. Jassem

    2015-02-01

    Full Text Available An experimental forced laminar study was presented in this research for an air flowing through a circular channel for different angles ( ,30o,45o,60o, the channel was heated at constant heat flux , the channel also was packed with steel and glass spheres respectively . The tests were done for three values of Peclets number (2111.71,3945.42,4575.47 with changing the heat flux for each case and five times for each number.The results showed that the dimensionless temperature distribution  will decrease with increasing the dimensionless channel length for all cases with changing Peclet number, heat flux and inclination angles, and its lowest value will be for glass spheres at highest flux, while at lower flux for , and the decreasing in dimensionless temperature was closed for both types of packed at other inclination angles.The study declared that the local Nusselt number decreases with increasing the dimensionless length of the channel for both packeds and for different applied heat flux, also through this study it was declared that the average Nusselt increases as Peclet number increases for both packed. Its value for the glass spheres is greater than the steel spheres with percentage (98.3% at small Peclet, and percentage (97.2% at large Peclet number for the horizontal tube, and (98.3% at small Peclet number and (97.8% at large Peclet number at  .Through this study its was found that average Nusselt number increases along the channel as the heat flux increases, because the bulk temperature will increase as the flow proceeds toward the end of the channel , so the heat transfer coefficient will increase.  It was declared from this study that in the case of the steel packed the heat transfer will occur mainly by conduction, while in the case of glass packed the heat transfer will occur mainly by laminar forced convection, where the lowest Nusselt number (Nu=3.8 was found when the pipe is horizontal and lowest heat flux and lowest Peclet number.  

  1. Residual stresses estimation in tubes after rapid heating of surface

    International Nuclear Information System (INIS)

    Serikov, S.V.

    1992-01-01

    Results are presented on estimation of residual stresses in tubes of steel types ShKh15, EhP836 and 12KIMF after heating by burning pyrotechnic substance inside tubes. External tube surface was heated up to 400-450 deg C under such treatment. Axial stresses distribution over tube wall thickness was determined for initial state, after routine heat treatment and after heating with the use of fireworks. Inner surface heating was shown to essentially decrease axial stresses in tubes

  2. Automated Diagnosis and Classification of Steam Generator Tube Defects

    International Nuclear Information System (INIS)

    Garcia, Gabe V.

    2004-01-01

    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

  3. 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.

  4. Drift tubes of Linac 2

    CERN Multimedia

    CERN PhotoLab

    1977-01-01

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

  5. Detailed Root Cause Analysis of SG Tube ODSCC Indications within the Tube Sheets of NPP Biblis Unit A

    Science.gov (United States)

    Kilian, R.; Beck, J.; Lang, H.; Schönherr, T.; Widera, M.

    Biblis Unit A is a Siemens/KWU type four loop PWR equipped with SG tubing made from Stainless Steel Alloy 800, operating from 1975 until the shutdown in 2011 due to the German political decision of a quick nuclear phase out. During the regular SG tubing inspections using eddy current testing in 2005 and 2006, a few SG tube indications were detected within the tube sheet between upper and lower mechanical tube expansion. These indications were limited to the outer tube bundle periphery. As a consequence two tubes with EC indications were pulled in 2006 for further investigations. The destructive examinations revealed axially oriented cracks starting from the outer tube surface (ODSCC). The analysis of the debris from the upper expansion area clearly indicated the presence of secondary side water in the volume between tube sheet and SG tube. Penetration of secondary side water is only possible by a penetration path along the upper expansion.

  6. An Accounting Mechanism of the Protrusion Effect in the Annular Channel When Calculating the Leontiev Tube

    Directory of Open Access Journals (Sweden)

    N. A. Kiselev

    2017-01-01

    Full Text Available The paper analyses a technique to calculate the Leontiev tube and shows that there are several ways to increase operating efficiency of this device of gas-dynamic energy separation. Application of regular relief (dimples and protrusions on the wall between supersonic and subsonic channels is one of them.Analyses the results available in publications of experimentally numerically investigated influence of semi-spherical protrusions in the slot channels on the enhancement of heat transfer and drag coefficients at various Reynolds numbers.Shows that at the laminar flow owing to semi-spherical protrusions in the slot channel a heat transfer coefficient can be 1.1‑2.6 times increased with simultaneous 1.7‑4.8 times growth of drag coefficient (as compared to the smooth channel.At transition and turbulent flows the heat transfer enhancement, because of shallow dimples (depth-to-print diameter ratio is from 0.1 to 0.25, can reach 1.1‑2.4 times, with simultaneous 1.2‑7.9 times growth of the drag coefficient (as compared to smooth channel.Using the higher protrusions can provide up to 3.0‑3.5 times heat transfer intensification, but in this case there is an outrunning growth of the drag coefficient.It is shown that the staggered array of the shallow spherical protrusions is advisable to use for heat transfer enhancement in the subsonic channel of the Leontiev tube. The shallow spherical dimples correspond to them and operate as heat transfer intensifiers in the supersonic channel.The paper proposes a mechanism that enables taking into consideration an impact of the protrusions in the slot channel on the intensification of the heat transfer and momentum processes when calculating the gas-dynamic energy separation device (Leontiev tube using the known (earlier published technique.The study has been implemented under supporting Grant no. 15-08-08428 of the Russian Foundation for Basic Research.

  7. Tracheostomy tube - speaking

    Science.gov (United States)

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

  8. X-ray tubes

    International Nuclear Information System (INIS)

    Young, R.W.

    1979-01-01

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

  9. Neural Tube Defects

    Science.gov (United States)

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

  10. Jejunostomy feeding tube

    Science.gov (United States)

    ... may replace the tube every now and then. Cleaning the Skin Around the J-tube To clean ... this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial ...

  11. The effects of frost thickness on the heat transfer of finned tube heat exchanger subject to the combined influence of fan types

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Jeng-Min; Hsieh, Wen-Chien; Ke, Xin-Ji [Department of Refrigeration, Air Conditioning National Chin-Yi University of Technology, Taichung County, Taiping City 411 (China); Wang, Chi-Chuan [Energy and Environment Research Laboratories, Industrial Technology Research Institute, Hsinchu 310 (China)

    2008-05-15

    This study conducts a numerical study concerning the effect of frost thickness on the heat transfer performance of a four rows plate finned tube heat exchanger. Calculations are made under constant air volume and variable air volume conditions. It is found that the initial surge of heat transfer rate in the frosted finned tube heat exchanger is mainly associated with the critical radius effect rather than the surface roughness. The frost thermal conductivity plays an important role in the surge phenomenon. There is hardly any initial surge when frost thermal conductivity is below 0.1 W m{sup -1} K{sup -1}. It is also recommended that a refrigerator should defrost when half of a single flow channel area is blocked by frost. The calculations also reveal that a centrifugal fan is recommended with a small fin-pitch heat exchanger. However, if a long term operation at a thick frost situation is unavoidable, an axial fan should be selected. There is no great difference between selection of an axial fan or centrifugal fan for a larger fin pitch heat exchanger. (author)

  12. Nasogastric and feeding tubes.

    Science.gov (United States)

    Gharib, Ahmed M; Stern, Eric J; Sherbin, Vandy L; Rohrmann, Charles A

    1996-05-01

    Preview The authors' experience in a radiology department suggested to them that there is a wide range of beliefs among practitioners regarding proper placement of nasogastric and feeding tubes. Improper positioning can cause serious problems, as they explain. Indications for different tube positions, complications of incorrect tube placement, and directions for proper positioning are discussed and illustrated.

  13. Microbial Contamination of Orthodontic Buccal Tubes from Manufacturers

    Directory of Open Access Journals (Sweden)

    Kok-Gan Chan

    2010-09-01

    Full Text Available This study aimed to test the sterility of new unused orthodontic buccal tubes received from manufacturers. Four different types of buccal tubes were used straight from the manufactures package without any additional sterilizing step. Of these buccal tubes tested, three genera of bacteria, implicated as opportunistic pathogens, namely Micrococcus luteus, Staphylococcus haemolyticus and Acinetobacter calcoaceticus were recovered from these buccal tubes. Our data showing microbial contamination on buccal tubes highlights the need of sterilization before clinical use. We also suggest that manufacturers should list the sterility state of orthodontic buccal tubes on their packaging or instructions stating the need for sterilization.

  14. 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...

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

    Science.gov (United States)

    2010-04-01

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

  16. Shape Modeling of a Concentric-tube Continuum Robot

    DEFF Research Database (Denmark)

    Bai, Shaoping; Xing, Charles Chuhao

    2012-01-01

    Concentric-tube continuum robots feature with simple and compact structures and have a great potential in medical applications. The paper is concerned with the shape modeling of a type of concentric-tube continuum robot built with a collection of super-elastic NiTiNol tubes. The mechanics...

  17. X-ray tubes for computed tomography

    International Nuclear Information System (INIS)

    Kotabe, Munenori; Sado, Noriyuki; Tachiki, Shigeru; Kitsuya, Minoru

    1979-01-01

    The X-ray tomography by computer processing (CT) is rapidly spreading because of the capabilities to obtain useful diagnostic information quantitatively, which was not able to be obtained by conventional X-ray photography, and to perform no-intrusion inspection, because it can picture the difference of X-ray absorption coefficient of several per cent in the soft tissues inside craniums. As the X-ray tubes to meet these requirements, the fixed anode X-ray tubes having high continuous rating are required for head CT, while the rotary anode X-ray tubes having the large cumulative heat capacity of anodes for whole body CT. Hitachi Ltd. has developed the X-ray tubes of type H 7129 of 4 kW rating for head CT and of type UJ-6FC-05V of 300 kHU (heat unit) for whole body CT. The specifications required for respective X-ray tubes include several items, and the maximum working tube voltage, focusing dimensions, long or short term maximum input and others are reported for the above described tubes. The performance centering around the loading life-time is described. In the tubes for whole body CT, repeated loading is also investigated. For the assumed input of 70,000 HU/slice, repeated loading of 10 times or more is possible in both cases when the input is repeatedly applied at loading intervals of 90 and 120 sec. (Wakatsuki, Y.)

  18. NEI You Tube Videos: Amblyopia

    Medline Plus

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

  19. NEI You Tube Videos: Amblyopia

    Medline Plus

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

  20. NEI You Tube Videos: Amblyopia

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

  1. Everything the nurse practitioner should know about pediatric feeding tubes.

    Science.gov (United States)

    Hannah, Erin; John, Rita Marie

    2013-11-01

    To provide an overview of the current feeding tubes in use in the pediatric population including feeding tube complications, and specific guidance for patients at the initiation, throughout the use of, and at the discontinuation of tube feeding. A review of the literature was performed using multiple databases including PubMed, CINAHL, Ovid Medline, and Cochrane Library. Key words used included pediatric gastrostomy (G) tubes, nasogastric (NG) tubes, gastrojejunostomy (GJ) tubes, enteral access, and nurse practitioner (NP). Any child who cannot obtain nutrition orally is a candidate for enteral feeding tube access. Tube feeding is the recommended care guideline for children that are undernourished or unable to safely take-in oral nutrition. Tube feeding has been known to improve health-related quality of life. There are a number of different forms of feeding tubes that can be used in children, including NG, orogastric, G, and GJ tubes. Children are being sent home regularly with enteral feeding tube access and NPs will encounter these patients in everyday practice. It is important that NPs know the risks and benefits of tube feeding as well as the types of tubes currently in use and their indications, advantages, disadvantages, and complications. ©2013 The Author(s) ©2013 American Association of Nurse Practitioners.

  2. Flux Tube Dynamics in the Dual Superconductor

    International Nuclear Information System (INIS)

    Lampert, M.; Svetitsky, B.

    1999-01-01

    We have studied plasma oscillations in a flux tube created in a dual superconductor. The theory contains an Abelian gauge field coupled magnetically to a Higgs field that confines electric charge via the dual Meissner effect. Starting from a static flux tube configuration, with electric charges at either end, we release a fluid of electric charges in the system that accelerate and screen the electric field. The weakening of the electric field allows the flux tube to collapse, and the inertia of the charges forces it open again. We investigate both Type I and Type II superconductors, with plasma frequencies both above and below the threshold for radiation into the Higgs vacuum. (The parameters appropriate to QCD are in the Type II regime; the plasma frequency depends on the mass taken for the fluid constituents.) The coupling of the plasma oscillations to the Higgs field making up the flux tube is the main new feature in our work

  3. Fluid heating by current injection tubes; Chauffage de fluides par tubes a passage de courant

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, L.S. [Societe Parmilleux (France)

    1999-04-01

    Current injection tube technology may be applied in compact fluid heating installation with a very low level of thermal inertia. The technology is particularly suitable for heating heat-sensitive fluids or those with a tendency to foul other types of installations. Specific advantages of current injection tubes include the elimination of cold spots and their reduced volume requirements. (author)

  4. Coke from small-diameter tubes analyzed

    International Nuclear Information System (INIS)

    Albright, L.F.

    1988-01-01

    The mechanism for coke deposit formation and the nature of the coke itself can vary with the design of the ethylene furnace tube bank. In this article, coke deposits from furnaces with small-diameter pyrolysis tubes are examined. The samples were taken from four furnaces of identical design (Plant B). As in both the first and second installments of the series, the coke deposits were examined using a scanning electron microscope (SEM) and an energy dispersive X-ray analyzer (EDAX). The deposits from the small-diameter tubes are compared with the coke deposits from the furnace discussed in earlier articles. Analysis of the coke in both sets of samples are then used to offer recommendations for improved decoking procedures, operating procedures, better feed selection, and better selection of the metallurgy used in furnace tubes, to extend the operating time of the furnace tubes by reducing the amount and type of coke build up

  5. Lunar Lava Tube Sensing

    Science.gov (United States)

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

    1992-01-01

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

  6. Steam generator tube performance

    International Nuclear Information System (INIS)

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

    1983-08-01

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

  7. X-ray tube target

    International Nuclear Information System (INIS)

    Weber, R.G.

    1980-01-01

    A target with an improved heat emissive surface for use in a rotating anode type x-ray tube is described. The target consists of a body having a first surface portion made of x-ray emissive material and a second surface portion made of a heat emissive material comprising at least one of hafnium boride, hafnium oxide, hafnium nitride, hafnium silicide, and hafnium aluminide. (U.K.)

  8. 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.

  9. Working session 1: Tubing degradation

    International Nuclear Information System (INIS)

    Kharshafdjian, G.; Turluer, G.

    1997-01-01

    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 MESSclose 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

  10. Manual tube welding torch

    International Nuclear Information System (INIS)

    Kiefer, J.H.; Smith, D.J.

    1981-01-01

    In a welding torch which fits over a tube intermediate the ends thereof for welding the juncture between the tube and a boss on the back side of a tube plate, a split housing encloses a tungsten electrode, a filler wire duct and a fiber optic bundle arranged to observe the welding process. A shielding gas duct is provided in the housing. A screw is provided for setting electrode/work distance. Difficult remote tube welding operations can be performed with the apparatus. (author)

  11. Steam generator tube performance

    International Nuclear Information System (INIS)

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

    1984-10-01

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

  12. Wound tube heat exchanger

    Science.gov (United States)

    Ecker, Amir L.

    1983-01-01

    What is disclosed is a wound tube heat exchanger in which a plurality of tubes having flattened areas are held contiguous adjacent flattened areas of tubes by a plurality of windings to give a double walled heat exchanger. The plurality of windings serve as a plurality of effective force vectors holding the conduits contiguous heat conducting walls of another conduit and result in highly efficient heat transfer. The resulting heat exchange bundle is economical and can be coiled into the desired shape. Also disclosed are specific embodiments such as the one in which the tubes are expanded against their windings after being coiled to insure highly efficient heat transfer.

  13. Sapphire tube pressure vessel

    Science.gov (United States)

    Outwater, John O.

    2000-01-01

    A pressure vessel is provided for observing corrosive fluids at high temperatures and pressures. A transparent Teflon bag contains the corrosive fluid and provides an inert barrier. The Teflon bag is placed within a sapphire tube, which forms a pressure boundary. The tube is received within a pipe including a viewing window. The combination of the Teflon bag, sapphire tube and pipe provides a strong and inert pressure vessel. In an alternative embodiment, tie rods connect together compression fittings at opposite ends of the sapphire tube.

  14. 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.

  15. Cadherin-6 type 2, K-cadherin (CDH6) is regulated by mutant p53 in the fallopian tube but is not expressed in the ovarian surface.

    Science.gov (United States)

    Karthikeyan, Subbulakshmi; Lantvit, Daniel D; Chae, Dam Hee; Burdette, Joanna E

    2016-10-25

    High-grade serous ovarian cancer (HGSOC) is the most lethal gynecological malignancy and may arise in either the fallopian tube epithelium (FTE) or ovarian surface epithelium (OSE). A mutation in p53 is reported in 96% of HGSOC, most frequently at R273 and R248. The goal of this study was to identify specific gene targets in the FTE that are altered by mutant p53, but not in the OSE. Gene analysis revealed that both R273 and R248 mutant p53 reduces CDH6 expression in the oviduct, but CDH6 was not detected in murine OSE cells. p53R273H induced SLUG and FOXM1 while p53R248W did not induce SLUG and only modestly increased FOXM1, which correlated with less migration as compared to p53R273H. An oviduct specific PAX8Cre/+/p53R270H/+ mouse model was created and confirmed that in vivo mutant p53 repressed CDH6 but was not sufficient to stabilize p53 expression alone. Overexpression of mutant p53 in the p53 null OVCAR5 cells decreased CDH6 levels indicating this was a gain-of-function. SLUG knockdown in murine oviductal cells with p53R273H restored CDH6 repression and a ChIP analysis revealed direct binding of mutant p53 on the CDH6 promoter. NSC59984, a small molecule that degrades mutant p53R273H, rescued CDH6 expression. In summary, CDH6 is expressed in the oviduct, but not the ovary, and is repressed by mutant p53. CDH6 expression with further validations may aide in establishing markers that inform upon the cell of origin of high grade serous tumors.

  16. Tube vibration in industrial size test heat exchanger

    International Nuclear Information System (INIS)

    Halle, H.; Wambsganss, M.W.

    1980-03-01

    Tube vibration data from tests of a specially built and instrumented, industrial-type, shell-and-tube heat exchanger are reported. The heat exchanger is nominally 0.6 m (2 ft) in dia and 3.7 m (12 ft) long. Both full tube and no-tubes-in-window bundles were tested for inlet/outlet nozzles of different sizes and with the tubes supported by seven, equally-spaced, single-segmental baffles. Prior to water flow testing, natural frequencies and damping of representative tubes were measured in air and water. Flow testing was accomplished by increasing the flow rates in stepwise fashion and also by sweeping through a selected range of flow rates. The primary variables measured and reported are tube accelerations and/or displacements and pressure drop through the bundle. Tests of the full tube bundle configuration revealed tube rattling to occur at intermediate flow rates, and fluidelastic instability, with resultant tube impacting, to occur when the flow rate exceeded a threshold level; principally, the four-span tubes were involved in the regions immediately adjacent to the baffle cut. For the range of flow rates tested, fluidelastic instability was not achieved in the no-tubes-in-window bundle; in this configuration the tubes are supported by all seven baffles and are, therefore, stiffer

  17. 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.

  18. Steam generator tube failures

    International Nuclear Information System (INIS)

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

    1996-04-01

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

  19. Rejection index for pressure tubes

    International Nuclear Information System (INIS)

    Mitchell, A.B.; Meneley, D.

    1989-10-01

    The objective of the present study was to establish a set of criteria (or Rejection Index) which could be used to decide whether a zirconium-2 1/2 w/o niobium pressure tube in a CANDU reactor should be removed from service due to in-service degradation. A critique of key issues associated with establishing a realistic rejection index was prepared. Areas of uncertainty in available information were identified and recommendations for further analysis and laboratory testing made. A Rejection Index based on the following limits has been recommended: 1) Limits related to design intent and normal operation: any garter spring must remain within the tolerance band specified for its design location; the annulus gas system must normally be operated in a circulating mode with a procedure in place for purging to prevent accumulation of deuterium. It must remain sensitive to leaks into any part of the systems; and pressure tube dimensions and distortions must be limited to maintain the fuel channels within the original design intent; 2) Limits related to defect tolerance: adequate time margins between occurrence of a leaking crack and unstable failure must be demonstrated for all fuel channels; long lap-type flaws are unacceptable; crack-like defects of any size are unacceptable; and score marks, frat marks and other defects with contoured profiles must fall below certain depth, length and stress intensity limits; and 3) Limits related to property degradation: at operating temperature each pressure tube must be demonstrated to have a critical length in excess of a stipulated value; the maximum equivalent hydrogen level in any pressure tube should not exceed a limit which should be defined taking into account the known history of that tube; the maximum equivalent hydrogen level in any rolled joint should not exceed a limit which is presently recommended as 200 ppm equivalent hydrogen; and the maximum diametral creep strain should be limited to less than 5%

  20. Chest Tube Thoracostomy

    Science.gov (United States)

    ... in the space around the lungs (called a pleural effusion) . A chest tube may also be needed when a patient has ... or chest CT are also done to evaluate pleural fluid. If the X-ray shows a need for a chest tube to drain fluid or air, the procedure is ...

  1. Rapid genetic typing of diarrheagenic Escherichia coli using a two-tube modified molecular beacon based multiplex real-time PCR assay and its clinical application.

    Science.gov (United States)

    Chen, Qingliang; Shi, Xiaolu; Li, Yinghui; Jiang, Yixiang; Lin, Yiman; Qiu, Yaqun; Li, Qingge; Hu, Qinghua

    2014-07-15

    Diarrheagenic Escherichia coli (DEC), including Enterotoxigenic E.coli (ETEC), Enteroaggregative E.coli (EAEC), Enteropathogenic E.coli (EPEC), Enterohemolysin E.coli (EHEC) and Enteroinvasive E.coli (EIEC) causes diarrhea or hemolytic uremic syndromes among infants and travelers around the world. A rapid, reliable and repeatable method is urgent for identifying DEC so as to provide the reference for responding to diarrheal disease outbreak and the treatment of the diarrheal patients associated with DEC. In this study, specific primers and modified molecular beacon probes of nine specific virulence genes, whose 5'end were added with homo tail sequence, were designed; and a two-tube modified molecular beacon based multiplex real-time PCR (rtPCR) assay for the identification of five Escherichia coli pathotypes, including ETEC, EAEC, EPEC, EHEC and EIEC was developed and optimized. Totally 102 bacterial strains, including 52 reference bacterial strains and 50 clinical strains were detected to confirm whether the target genes selected were specific. Then detection limits of the assay were tested. Lastly, the assay was applied to the detection of 11860 clinical samples to evaluate the specificity and sensitivity of the developed assay compared with the conventional PCR. The target genes were 100% specific as assessed on 102 bacterial strains since no cross-reactions were observed. The detection limits ranged from 88 CFU/mL (EHEC) to 880 CFU/mL (EPEC). Compared with the conventional PCR, the specificity and sensitivity of the multiplex rtPCR was 100% and over 99%, respectively. The coefficient of variation (CV) for each target gene ranged from 0.45% to 1.53%. 171 positive clinical samples were mostly identified as ETEC (n = 111, 64.9%) and EPEC (n = 38, 22.2%), which were the dominating pathotypes of DEC strains. The developed multiplex rtPCR assay for the identification of DEC was high sensitive and specific and could be applied to the rapid identification of

  2. Ventricular tachycardia following tube thoracotomy.

    Science.gov (United States)

    Hibbert, Benjamin; Lim, Toon Wei; Hibbert, Rebecca; Green, Martin; Gollob, Michael H; Davis, Darryl R

    2010-10-01

    Arrhythmias provoked by tube thoracotomy are a rare complication. We report a ventricular tachycardia after chest tube insertion for a device-related pneumothorax. Sinus rhythm was restored only by removal of the chest tube and insertion of a pliable pleural drain. Identification of the chest tube as an arrhythmic trigger following tube thoracotomy is essential in definitive management of refractory arrhythmias.

  3. 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.

  4. 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...

  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. The Type VI Secretion TssEFGK-VgrG Phage-Like Baseplate Is Recruited to the TssJLM Membrane Complex via Multiple Contacts and Serves As Assembly Platform for Tail Tube/Sheath Polymerization.

    Directory of Open Access Journals (Sweden)

    Yannick R Brunet

    2015-10-01

    Full Text Available The Type VI secretion system (T6SS is a widespread weapon dedicated to the delivery of toxin proteins into eukaryotic and prokaryotic cells. The 13 T6SS subunits assemble a cytoplasmic contractile structure anchored to the cell envelope by a membrane-spanning complex. This structure is evolutionarily, structurally and functionally related to the tail of contractile bacteriophages. In bacteriophages, the tail assembles onto a protein complex, referred to as the baseplate, that not only serves as a platform during assembly of the tube and sheath, but also triggers the contraction of the sheath. Although progress has been made in understanding T6SS assembly and function, the composition of the T6SS baseplate remains mostly unknown. Here, we report that six T6SS proteins-TssA, TssE, TssF, TssG, TssK and VgrG-are required for proper assembly of the T6SS tail tube, and a complex between VgrG, TssE,-F and-G could be isolated. In addition, we demonstrate that TssF and TssG share limited sequence homologies with known phage components, and we report the interaction network between these subunits and other baseplate and tail components. In agreement with the baseplate being the assembly platform for the tail, fluorescence microscopy analyses of functional GFP-TssF and TssK-GFP fusion proteins show that these proteins assemble stable and static clusters on which the sheath polymerizes. Finally, we show that recruitment of the baseplate to the apparatus requires initial positioning of the membrane complex and contacts between TssG and the inner membrane TssM protein.

  7. Automation in tube finishing bay

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  8. 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)

  9. Intermediate heat exchanger tube vibration induced by cross and parallel mixed flow

    International Nuclear Information System (INIS)

    Kawamura, Koji

    1986-01-01

    The characteristics of pool type LMFBR intermediate heat exchanger (IHX) tube vibrations induced by cross and parallel mixed flow were basically investigated. Secondary coolant in IHX tube bundle is mixed flow of parallel jit flow along the tube axis through flow holes in baffle plates and cross flow. By changing these two flow rate, flow distributions vary in the tube bundle. Mixed flow also induces vibrations which cause fretting wear and fatigue of tube. It is therefore very important to evaluate the tube vibration characteristics for estimating the tube integrity. The results show that the relationships between tube vibrations and flow distributions in the tube bundle were cleared, and mixed flow induced tube vibration could be evaluated on the base of the characteristics of both parallel and cross flow induced vibration. From these investigations it could be concluded that the characteristics of tube vibration for various flow distributions can be systematically evaluated. (author)

  10. X-ray tube

    International Nuclear Information System (INIS)

    Webley, R.S.

    1975-01-01

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

  11. Tube Alinement for Machining

    Science.gov (United States)

    Garcia, J.

    1984-01-01

    Tool with stepped shoulders alines tubes for machining in preparation for welding. Alinement with machine tool axis accurate to within 5 mils (0.13mm) and completed much faster than visual setup by machinist.

  12. Steam generator tube performance

    International Nuclear Information System (INIS)

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

    1982-04-01

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

  13. Ear tube insertion

    Science.gov (United States)

    ... mastoiditis) or the brain, or that damages nearby nerves Injury to the ear after sudden changes in ... does not heal after the tube falls out. Most of the time, these problems DO NOT last long. They also ...

  14. Tube Feeding Troubleshooting Guide

    Science.gov (United States)

    ... the diameter is measured in units known as French sizes, or “Fr”; a low profile tube also ... your quality of life. You are encouraged to speak with your physician, dietitian, home care company, or ...

  15. Measurements of absorbed heat flux and water-side heat transfer coefficient in water wall tubes

    Science.gov (United States)

    Taler, Jan; Taler, Dawid; Kowal, Andrzej

    2011-04-01

    The tubular type instrument (flux tube) was developed to identify boundary conditions in water wall tubes of steam boilers. The meter is constructed from a short length of eccentric tube containing four thermocouples on the fire side below the inner and outer surfaces of the tube. The fifth thermocouple is located at the rear of the tube on the casing side of the water-wall tube. The boundary conditions on the outer and inner surfaces of the water flux-tube are determined based on temperature measurements at the interior locations. Four K-type sheathed thermocouples of 1 mm in diameter, are inserted into holes, which are parallel to the tube axis. The non-linear least squares problem is solved numerically using the Levenberg-Marquardt method. The heat transfer conditions in adjacent boiler tubes have no impact on the temperature distribution in the flux tubes.

  16. Hydroformability study of seamless tube using Gurson-Tvergaard-Needleman (GTN) fracture model

    Science.gov (United States)

    Harisankar, K. R.; Omar, A.; Narasimhan, K.

    2017-09-01

    Tube hydroforming process is an advanced manufacturing process in which tube acting as blank is placed in between the dies and deformed with the help of hydraulic pressure. It has several advantages over conventional stamping process such as high strength to weight ratio, higher reliability, less tooling cost etc. Fracture surface investigation of tube hydroformed samples reveal dimple formation in the form of void coalescence which is a characteristic feature of ductile fracture. Hence, in order to accurately predict the limiting strains at fracture it is important to model the process using ductile damage criteria. Fracture criteria are broadly classified into two, microscopic and macroscopic. In the present work Gurson-Tvergaard-Neeedleman (GTN) model, which is a microscopic based ductile damage criteria, was used for predicting the limiting strains at fracture for seamless steel tubes and implemented in explicit finite element software, ABAQUS, for variety of strain path and boundary conditions to obtain fracture based forming limit diagram. The original void porosity, the critical porosity and fracture porosity of the Gurson-Tvergaard-Needleman model were determined by image analysis of scanning electron micrographs of the specimen at different testing conditions of the uniaxial tensile test. The other parameters of the model were determined by using inverse approach combined with uniaxial tensile test and simulation. Predicted FLD is found to be in good agreement with the experimental FLD. Furthermore, numerical simulation based parametric study was carried out to understand the impact of various GTN parameters on different aspects of formability parameters such as bursting pressure, bulge height, principal strains and strain path to develop the understanding of deformation and fracture behaviour at the micro-level during tube hydroforming process.

  17. 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

  18. Effect of impurity on electronic properties of carbon nano tubes

    International Nuclear Information System (INIS)

    Jalili, S.; Jafari, M.; Habibian, J.

    2008-01-01

    We have studied the effect of impurity on electronic properties of single-walled carbon nano tubes using Density Functional Theory. Electronic band structures and density of states of (4, 4) and (7, 0) carbon nano tubes in the presence of different amount of B and N impurities were calculated. It was found that these impurities have significant effect on the conductivity of carbon nano tubes. The metallic (4, 4) nano tube remains to be metallic after doping with B and N. The electronic properties of small gap semiconducting (7, 0) tube can extensively change in the presence of impurity. Our results indicate that B-doped and N-doped (7, 0) carbon nano tubes can be p-type and n-type semiconductors, respectively

  19. Evaluation of the Effect of Tube Pitch and Surface Alterations on Temperature Field at Sprinkled Tube Bundle

    Science.gov (United States)

    Kracík, Petr; Copek, Tomáš; Zachar, Martin; Pospíšil, Jiří

    2015-05-01

    Water flowing on a sprinkled tube bundle forms three basic modes: It is the Droplet mode (liquid drips from one tube to another), the Jet mode (with an increasing flow rate droplets merge into a column) and the Membrane (Sheet) mode (with further increasing of falling film liquid flow rate columns merge and create sheets between the tubes. With sufficient flow rate sheets merge at this state and the tube bundle is completely covered by a thin liquid film). There are several factors influencing the individual mode types as well as heat transfer. Beside the above mentioned falling film liquid flow rate they are for instance tube diameters, tube pitches in a tube bundle or a physical condition of a falling film liquid. This paper presents a summary of data measured at atmospheric pressure at a tube bundle consisting of copper tubes of 12 milimeters diameter and of the studied tube length one meter. The tubes are positioned horizontally one above another with the tested pitches of 15, 20, 25 and 30 mm and there is a distribution tube placed above them with water flowing out. The thermal gradient of 15-40 has been tested with all pitches where the falling film liquid's temperature at the inlet of the distribution tube was 15 °C. The liquid was heated during the flow through the exchanger and the temperature of the sprinkled (heater) liquid at the inlet of the exchanger with a constant flow rate about 7.2 litres per minute was 40 °C. The tested flow of the falling film liquid ranged from 1.0 to 13.0 litres per minute. Sequences of 180 exposures have been recorded in partial flow rate stages by thermographic camera with record frequency of 30 Hz which were consequently assessed using the Matlab programme. This paper presents results achieved at the above mentioned pitches and at three types of tube bundle surfaces.

  20. Evaluation of the Effect of Tube Pitch and Surface Alterations on Temperature Field at Sprinkled Tube Bundle

    Directory of Open Access Journals (Sweden)

    Kracík Petr

    2015-01-01

    Full Text Available Water flowing on a sprinkled tube bundle forms three basic modes: It is the Droplet mode (liquid drips from one tube to another, the Jet mode (with an increasing flow rate droplets merge into a column and the Membrane (Sheet mode (with further increasing of falling film liquid flow rate columns merge and create sheets between the tubes. With sufficient flow rate sheets merge at this state and the tube bundle is completely covered by a thin liquid film. There are several factors influencing the individual mode types as well as heat transfer. Beside the above mentioned falling film liquid flow rate they are for instance tube diameters, tube pitches in a tube bundle or a physical condition of a falling film liquid. This paper presents a summary of data measured at atmospheric pressure at a tube bundle consisting of copper tubes of 12 milimeters diameter and of the studied tube length one meter. The tubes are positioned horizontally one above another with the tested pitches of 15, 20, 25 and 30 mm and there is a distribution tube placed above them with water flowing out. The thermal gradient of 15–40 has been tested with all pitches where the falling film liquid’s temperature at the inlet of the distribution tube was 15 °C. The liquid was heated during the flow through the exchanger and the temperature of the sprinkled (heater liquid at the inlet of the exchanger with a constant flow rate about 7.2 litres per minute was 40 °C. The tested flow of the falling film liquid ranged from 1.0 to 13.0 litres per minute. Sequences of 180 exposures have been recorded in partial flow rate stages by thermographic camera with record frequency of 30 Hz which were consequently assessed using the Matlab programme. This paper presents results achieved at the above mentioned pitches and at three types of tube bundle surfaces.

  1. Gastrostomy feeding tube - pump - child

    Science.gov (United States)

    ... tube feeding; PEG tube care; Feeding - gastrostomy tube - pump; G-tube - pump; Gastrostomy button - pump; Bard Button - pump; MIC-KEY - pump ... Gather supplies: Feeding pump (electronic or battery powered) Feeding ... pump (includes a feeding bag, drip chamber, roller clamp, ...

  2. NEI You Tube Videos: Amblyopia

    Medline Plus

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

  3. Development of a sealing process of capsules for surveillance test tubes of the vessel in nuclear power plants

    International Nuclear Information System (INIS)

    Romero C, J.; Fernandez T, F.; Perez R, N.; Rocamontes A, M.; Garcia R, R.

    2007-01-01

    The surveillance capsule is composed by the support, three capsules for impact test tubes, five capsules for tension test tubes and one porta dosemeters. The capsules for test tubes are of two types: rectangular capsule for Charpy test tubes and cylindrical capsule for tension test tubes. This work describes the development of the welding system to seal the capsules for test tubes that should contain helium of ultra high purity to a pressure of 1 atmosphere. (Author)

  4. Development of stabilizers for steam generator tube repair

    International Nuclear Information System (INIS)

    Au-Yang, M.K.

    1987-01-01

    Fluidelastic stability, turbulence-induced and vortex-induced vibration analysis of different types of stabilizers for repairing steam generator tubes are presented. The performances of the different designs are compared with that of a common basis - the virgin tube. It was found that in addition to permitting the stabilized tubes to remain in operation, the sleeve has the additional merit of being the best performer of all the designs. In addition, it is adaptable to remote installation. (orig.)

  5. Investigations on high-pressure ribbed tubes

    Energy Technology Data Exchange (ETDEWEB)

    Kling, G.

    1942-05-01

    During hydrogenation of coal, the reactants (coal paste and hydrogen) had to be heated to reaction temperature partly by heat exchange with products and partly by heating in hairpin tubes of a preheater. These hairpin tubes were heated externally by hot circulating gases. In order to improve heat transfer from the gases to the tubes, various types of metal ribbing were welded to the tubes to catch more heat and transfer it to the tubes. This report detailed some studies on the best shapes and dimensions and numbers of plates to be used. The report was limited to flat, rectangular-cross-section plates attached perpendicularly, instead of including flat circular plates, spiral plates, or other configurations. The advantage of greater surface area to catch more heat had to be balanced off against the disadvantage of greater surface area to absorb more heat in internal resistance to heat flow. The report described the experimental conditions, the modifications tested, and the shape decided upon as best for flat plates. Some of the diagrams illustrating temperature distributions around the tubes and ribs were presented in imitation three-dimenional formats. 16 figures.

  6. 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.

  7. Theoretical and experimental investigations on the cooling capacity distributions at the stages in the thermally-coupled two-stage Stirling-type pulse tube cryocooler without external precooling

    Science.gov (United States)

    Tan, Jun; Dang, Haizheng

    2017-03-01

    The two-stage Stirling-type pulse tube cryocooler (SPTC) has advantages in simultaneously providing the cooling powers at two different temperatures, and the capacity in distributing these cooling capacities between the stages is significant to its practical applications. In this paper, a theoretical model of the thermally-coupled two-stage SPTC without external precooling is established based on the electric circuit analogy with considering real gas effects, and the simulations of both the cooling performances and PV power distribution between stages are conducted. The results indicate that the PV power is inversely proportional to the acoustic impedance of each stage, and the cooling capacity distribution is determined by the cold finger cooling efficiency and the PV power into each stage together. The design methods of the cold fingers to achieve both the desired PV power and the cooling capacity distribution between the stages are summarized. The two-stage SPTC is developed and tested based on the above theoretical investigations, and the experimental results show that it can simultaneously achieve 0.69 W at 30 K and 3.1 W at 85 K with an electric input power of 330 W and a reject temperature of 300 K. The consistency between the simulated and the experimental results is observed and the theoretical investigations are experimentally verified.

  8. Compounded Apixaban Suspensions for Enteral Feeding Tubes.

    Science.gov (United States)

    Caraballo, Maria L; Donmez, Seda; Nathan, Kobi; Zhao, Fang

    2017-07-01

    Objective: There is limited information on compounded apixaban formulations for administration via enteral feeding tubes. This study was designed to identify a suitable apixaban suspension formulation that is easy to prepare in a pharmacy setting, is compatible with commonly used feeding tubes, and has a beyond-use date of 7 days. Methods: Apixaban suspensions were prepared from commercially available 5-mg Eliquis tablets. Several vehicles and compounding methods were screened for ease of preparation, dosage accuracy, and tube compatibility. Two tubing types, polyurethane and polyvinyl chloride, with varying lengths and diameters, were included in the study. They were mounted on a peg board during evaluation to mimic the patient body position. A 7-day stability study of the selected formulation was also conducted. Results: Vehicles containing 40% to 60% Ora-Plus in water all exhibited satisfactory flowability through the tubes. The mortar/pestle compounding method was found to produce more accurate and consistent apixaban suspensions than the pill crusher or crushing syringe method. The selected formulation, 0.25 mg/mL apixaban in 50:50 Ora-Plus:water, was compatible with both tubing types, retaining >98% drug in posttube samples. The stability study also confirmed that this formulation was stable physically and chemically over 7 days of storage at room temperature. Conclusions: A suitable apixaban suspension formulation was identified for administration via enteral feeding tubes. The formulation consisted of 0.25 mg/mL apixaban in 50:50 Ora-Plus:water. The stability study results supported a beyond-use date of 7 days at room temperature.

  9. Fill tube fitted spheres

    International Nuclear Information System (INIS)

    Ives, B.H.

    1981-01-01

    The high temperature diffusion technique for fuel filling of some future direct drive cryogenic ICF targets may be unacceptable. The following describes a technique of fitting a 1 mm diameter x 6 μm thick glass microsphere with an approx. 50 μm O.D. glass fill tube. The process of laser drilling a 50 μm diameter hole in the microsphere wall, technique for making the epoxy joint between the sphere and fill tube, as well as the assembly procedure are also discussed

  10. Effect of Blood Collection Tube Type and Time to Processing on the Enumeration and High-Content Characterization of Circulating Tumor Cells Using the High-Definition Single-Cell Assay.

    Science.gov (United States)

    Rodríguez-Lee, Mariam; Kolatkar, Anand; McCormick, Madelyn; Dago, Angel D; Kendall, Jude; Carlsson, Nils Anders; Bethel, Kelly; Greenspan, Emily J; Hwang, Shelley E; Waitman, Kathryn R; Nieva, Jorge J; Hicks, James; Kuhn, Peter

    2018-02-01

    - As circulating tumor cell (CTC) assays gain clinical relevance, it is essential to address preanalytic variability and to develop standard operating procedures for sample handling in order to successfully implement genomically informed, precision health care. - To evaluate the effects of blood collection tube (BCT) type and time-to-assay (TTA) on the enumeration and high-content characterization of CTCs by using the high-definition single-cell assay (HD-SCA). - Blood samples of patients with early- and advanced-stage breast cancer were collected into cell-free DNA (CfDNA), EDTA, acid-citrate-dextrose solution, and heparin BCTs. Time-to-assay was evaluated at 24 and 72 hours, representing the fastest possible and more routine domestic shipping intervals, respectively. - We detected the highest CTC levels and the lowest levels of negative events in CfDNA BCT at 24 hours. At 72 hours in this BCT, all CTC subpopulations were decreased with the larger effect observed in high-definition CTCs and cytokeratin-positive cells smaller than white blood cells. Overall cell retention was also optimal in CfDNA BCT at 24 hours. Whole-genome copy number variation profiles were generated from single cells isolated from all BCT types and TTAs. Cells from CfDNA BCT at 24-hour TTA exhibited the least noise. - Circulating tumor cells can be identified and characterized under a variety of collection, handling, and processing conditions, but the highest quality can be achieved with optimized conditions. We quantified performance differences of the HD-SCA for specific preanalytic variables that may be used as a guide to develop best practices for implementation into patient care and/or research biorepository processes.

  11. Pressure loss characteristics of LSTF steam generator heat-transfer tubes. Pressure loss increase due to tube internal instruments

    International Nuclear Information System (INIS)

    Suzuki, Mitsuhiro

    1994-11-01

    The steam generator of the Large-Scale Test Facility (LSTF) includes 141 heat-transfer U-tubes with different lengths. Six U-tubes among them are furnished with 15 or 17 probe-type instruments (conduction probe with a thermocouple; CPT) protuberant into the primary side of the U-tubes. Other 135 U-tubes are not instrumented. This results in different hydraulic conditions between the instrumented and non-instrumented U-tubes with the same length. A series of pressure loss characteristics tests was conducted at a test apparatus simulating both types of U-tube. The following pressure loss coefficient (K CPT ) was reduced as a function of Reynolds number (Re) from these tests under single-phase water flow conditions. K CPT =0.16 5600≤Re≤52820, K CPT =60.66xRe -0.688 2420≤Re≤5600, K CPT =2.664x10 6 Re -2.06 1371≤Re≤2420. The maximum uncertainty is 22%. By using these results, the total pressure loss coefficients of full length U-tubes were estimated. It is clarified that the total pressure loss of the shortest instrumented U-tube is equivalent to that of the middle-length non-instrumented U-tube and also that a middle-length instrumented U-tube is equivalent to the longest non-instrumented U-tube. Concludingly. it is important to take account of the CPT pressure loss mentioned above in estimation of fluid behavior at the non-instrumented U-tubes either by using the LSTF experiment data from the CPT-installed U-tubes or by using any analytical codes. (author)

  12. Manipulation and functionalization of nano-tubes: application to boron nitride nano-tubes

    International Nuclear Information System (INIS)

    Maguer, A.

    2007-01-01

    This PhD work is divided into two parts dealing with boron nitride (BNNT) and carbon nano-tubes. The first part is about synthesis, purification and chemical functionalization of BNNT. Single-walled BNNT are synthesized by LASER ablation of a hBN target. Improving the synthesis parameters first allowed us to limit the byproducts (hBN, boric acid). A specific purification process was then developed in order to enrich the samples in nano-tubes. Purified samples were then used to develop two new chemical functionalization methods. They both involve chemical molecules that present a high affinity towards the BN network. The use of long chain-substituted quinuclidines and borazines actually allowed the solubilization of BNNT in organic media. Purification and functionalization were developed for single-walled BNNT and were successfully applied to multi-walled BNNT. Sensibility of boron to thermic neutrons finally gave birth to a study about covalent functionalization possibilities of the network. The second part of the PhD work deals with separation of carbon nano-tubes depending on their properties. Microwave irradiation of carbon nano-tubes first allowed the enrichment of initially polydisperse samples in large diameter nano-tubes. A second strategy involving selective interaction between one type of tubes and fullerene micelles was finally envisaged to selectively solubilize carbon nano-tubes with specific electronic properties. (author) [fr

  13. 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.

  14. Steam generator tube vibration study

    International Nuclear Information System (INIS)

    Enderlin, W.I.

    1986-01-01

    Chemical cleaning has been proposed to remove magnetite buildup in some pressurized water reactor steam generators. The US Nuclear Regulatory Commission (NRC) has expressed concern that such cleaning would combine with the tube denting caused by magnetite formation to enlarge tube/tube support plate clearances, increasing the level of flow-induced vibrations that could lead to unacceptably high tube wear and failure rates. In support of NRC, the Pacific Northwest Laboratory investigated whether such increased clearances would exacerbate tube fretting wear. Using a full-length scale model of a steam generator tube bundle, flow tests were conducted at an instrumented location through clearances representing as-built and post-cleaned tube conditions. Test results indicated little potential for increased tube wear as a result of chemical cleaning, under normal operating conditions at tube support locations similar to that tested

  15. Identification and characterization of a viroid resembling apple dimple fruit viroid in fig (Ficus carica L.) by next generation sequencing of small RNAs.

    Science.gov (United States)

    Chiumenti, M; Torchetti, E M; Di Serio, F; Minafra, A

    2014-08-08

    Viroids are small (246-401 nt) circular and non coding RNAs infecting higher plants. They are targeted by host Dicer-like enzymes (DCLs) that generate small RNAs of 21-24 nt (sRNAs), which are involved in the host RNA silencing pathways. The accumulation in plant tissues of such viroid-derived small RNAs (vd-sRNAs) is a clear sign of an ongoing viroid infection. In this study, next generation sequencing of a sRNAs library and assembling of the sequenced vd-sRNAs were instrumental for the identification of a viroid resembling apple dimple fruit viroid (ADFVd) in a fig accession. After confirming by molecular methods the presence of this viroid in the fig tree, its population was characterized, showing that the ADFVd master sequence from fig diverges from that of the ADFVd reference variant from apple. Moreover, since this viroid accumulates at a low level in fig, a semi-nested RT-PCR assay was developed for detecting it in other fig accessions. ADFVd seems to have a wider host range than thought before and this poses questions about its epidemiology. A further characterization of ADFVd-sRNAs showed similar accumulation of (+) or (-) vd-sRNAs that mapped on the viroid genome generating hotspot profiles. Moreover, similarly to other nuclear-replicating viroids, vd-sRNAs of 21, 22 and 24 nt in size prevailed in the distribution profiles. Altogether, these data support the involvement of double-stranded RNAs and different DCLs, targeting the same restricted viroid regions, in the genesis of ADFVd-sRNAs. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Fuel assembly for pressure tube type reactor

    International Nuclear Information System (INIS)

    Wakabayashi, Toshio.

    1990-01-01

    For providing a effect of burnable poisons without worsening local power peaking, it is effective to dispose conventional fuel rods incorporated with burnable poisons uniformly to the outermost layer of a fuel assembly in which fuel rods are disposed concentrically in a multilayered state. However, since the irradiation is applied to the outermost layer with high neutron fluxes in this case, the burnable poisons are eliminated rapidly and excess reactivity suppression effect does not last sufficiently. Then, according to the present invention, pellets of a dual layer structure comprising a pellet containing burnable poisons disposed at the center and nuclear fuel materials composed of plutonium-uranium mixed oxides or uranium oxides coated therearound are disposed. In view of the above, it is possible to obtain a fuel assembly which does not increase the suppression of excess reactivity at the initial stage and does not promote the elimination of burnable poisons, without lowering the local power peaking. (T.M.)

  17. Flow-through microsensor array based on semipermeable dialysis tubing

    Science.gov (United States)

    Bohm, Sebastian; Olthuis, Wouter; Bergveld, Piet

    1999-11-01

    In this contribution, a flow-through potentiometric micro sensor is described which is based on semi-permeable tubing. Basically the proposed ion selective electrodes are of the liquid membrane type having an internal electrolyte. Sensors were constructed by guiding 0.3 mm diameter dialysis tube from an artificial kidney through a cavity, precision machined in PerspexTM.

  18. Eddy current testing of steam generator tubes

    International Nuclear Information System (INIS)

    Neumaier, P.

    1981-01-01

    A rotating probe is described for improving the inspection of tubes and end plate in steam generators. The method allows a representation of the whole defect, consequently the observer is able to determine directly the type of defect, signal processing in-line or off-line is possible [fr

  19. Noncontact measurement of electrostatic fields: Verification of modeled potentials within ion mobility spectrometer drift tube designs

    International Nuclear Information System (INIS)

    Scott, Jill R.; Tremblay, Paul L.

    2007-01-01

    The heart of an ion mobility spectrometer is the drift region where ion separation occurs. While the electrostatic potentials within a drift tube design can be modeled, no method for independently validating the electrostatic field has previously been reported. Two basic drift tube designs were modeled using SIMION 7.0 to reveal the expected electrostatic fields: (1) A traditional alternating set of electrodes and insulators and (2) a truly linear drift tube. One version of the alternating electrode/insulator drift tube and two versions of linear drift tubes were then fabricated. The stacked alternating electrodes/insulators were connected through a resistor network to generate the electrostatic gradient in the drift tube. The two linear drift tube designs consisted of two types of resistive drift tubes with one tube consisting of a resistive coating within an insulating tube and the other tube composed of resistive ferrites. The electrostatic fields within each type of drift tube were then evaluated by a noncontact method using a Kelvin-Zisman type electrostatic voltmeter and probe (results for alternative measurement methods provided in supplementary material). The experimental results were then compared with the electrostatic fields predicted by SIMION. Both the modeling and experimental measurements reveal that the electrostatic fields within a stacked ion mobility spectrometer drift tube are only pseudo-linear, while the electrostatic fields within a resistive drift tube approach perfect linearity

  20. Mineralization of Alvinella polychaete tubes at hydrothermal vents.

    Science.gov (United States)

    Georgieva, M N; Little, C T S; Ball, A D; Glover, A G

    2015-03-01

    Alvinellid polychaete worms form multilayered organic tubes in the hottest and most rapidly growing areas of deep-sea hydrothermal vent chimneys. Over short periods of time, these tubes can become entirely mineralized within this environment. Documenting the nature of this process in terms of the stages of mineralization, as well as the mineral textures and end products that result, is essential for our understanding of the fossilization of polychaetes at hydrothermal vents. Here, we report in detail the full mineralization of Alvinella spp. tubes collected from the East Pacific Rise, determined through the use of a wide range of imaging and analytical techniques. We propose a new model for tube mineralization, whereby mineralization begins as templating of tube layer and sublayer surfaces and results in fully mineralized tubes comprised of multiple concentric, colloform, pyrite bands. Silica appeared to preserve organic tube layers in some samples. Fine-scale features such as protein fibres, extracellular polymeric substances and two types of filamentous microbial colonies were also found to be well preserved within a subset of the tubes. The fully mineralized Alvinella spp. tubes do not closely resemble known ancient hydrothermal vent tube fossils, corroborating molecular evidence suggesting that the alvinellids are a relatively recent polychaete lineage. We also compare pyrite and silica preservation of organic tissues within hydrothermal vents to soft tissue preservation in sediments and hot springs. © 2014 The Authors. Geobiology Published by John Wiley & Sons Ltd.

  1. Estimating probable flaw distributions in PWR steam generator tubes

    International Nuclear Information System (INIS)

    Gorman, J.A.; Turner, A.P.L.

    1997-01-01

    This paper describes methods for estimating the number and size distributions of flaws of various types in PWR steam generator tubes. These estimates are needed when calculating the probable primary to secondary leakage through steam generator tubes under postulated accidents such as severe core accidents and steam line breaks. The paper describes methods for two types of predictions: (1) the numbers of tubes with detectable flaws of various types as a function of time, and (2) the distributions in size of these flaws. Results are provided for hypothetical severely affected, moderately affected and lightly affected units. Discussion is provided regarding uncertainties and assumptions in the data and analyses

  2. Characteristics and theory of operation of the controlatron neutron tube

    International Nuclear Information System (INIS)

    Volk, R.D.

    1977-01-01

    The Controlatron (or Type 26E) neutron tube was developed by General Electric under contract to Sandia Laboratories in 1961 to be used in a neutron activation analysis experiment on the lunar surface. It was subsequently employed as a very stable laboratory neutron source for neutron detector calibration within the ERDA complex. The Controlatron is a gas filled neutron tube using a titanium target, Penning type cold cathode ion source, and self-contained reservoir. The general theory of operation of this type of neutron tube utilizing the D-T nuclear reaction is presented

  3. 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.

  4. A New Resonance Tube

    Science.gov (United States)

    Bates, Alan

    2017-01-01

    The measurement of the speed of sound in air with the resonance tube is a popular experiment that often yields accurate results. One approach is to hold a vibrating tuning fork over an air column that is partially immersed in water. The column is raised and lowered in the water until the generated standing wave produces resonance: this occurs at…

  5. Thoughts of accelerator tubes

    International Nuclear Information System (INIS)

    Larson, J.D.

    1977-01-01

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

  6. Thoughts of accelerator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Larson, J D

    1977-01-01

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

  7. Eustachian Tube Dysfunction

    Science.gov (United States)

    ... When it is inflated, the balloon opens a pathway for mucus and air to flow through the tube. This can help it function properly. FDA warning The U.S. Food and Drug Administration (FDA) advises against the use of ear candles. ...

  8. Tube-dwelling invertebrates

    NARCIS (Netherlands)

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

    2015-01-01

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

  9. Chest tube insertion

    Science.gov (United States)

    ... of your chest cavity. This is called the pleural space. It is done to allow your lungs to fully expand. ... pneumothorax ) Fluid buildup in the chest (called a pleural ... in the esophagus (the tube that allows food to go from the mouth ...

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

    Science.gov (United States)

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

    2014-01-01

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

  11. Self-assembling segmented coiled tubing

    Science.gov (United States)

    Raymond, David W.

    2016-09-27

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

  12. Fireside carburization of stainless steel furnace tubes

    Energy Technology Data Exchange (ETDEWEB)

    Mirabal, E.; Molina, C. [PDVSA-Refineria Isla, Curayao (Netherlands); Mayorga, A.; Hau, J.L. [PDVSA-Intevep, Caracas (Venezuela)

    1999-11-01

    Most heavy Venezuelan crudes are recognized for having a high total acid number (TAN) that is usually associated with a high tendency to produce naphthenic acid corrosion. To resist this type of corrosion in vacuum heaters, 9Cr-1Mo steel and stainless steels containing molybdenum are usually recommended. In 1993 the original 5Cr-1/2Mo roof tubes of the furnace in a vacuum unit were replaced by stainless steel 316Ti to minimize tube replacement and increase heater reliability. Unexpectedly, some of the new tubes failed after only three years of service, and just one year after undergoing the last turnaround inspection. The damage occurred in the form of deep holes and perforations, starting from the outside tube surface on the fireside. Coke build-up occurred due to severe operating conditions, overheating the tubes on the fireside, above 675 C (1250 F). Metallographic and Scanning Electron Microscopic (SEM) examination revealed internal and external carburization of the material due to the presence of coke and combustion ashes, respectively. The increase in the skin metal temperature facilitated the diffusion of carbon from these carbon-rich deposits into the low carbon content material (0.023 O/O).Depletion of chromium at the grain boundaries due to the massive formation of chromium carbides, resulted in a severe intergranular corrosion attack by molten salts rich in vanadium and sulfur due to asphalt burning. Normal operating practice demands the use of steam for the heater tubes to control coke build-up. This practice had been first reduced and then eliminated, during the past two years prior to the failure, because of economic incentives. This paper describes the root cause analysis conducted to account for these premature tube failures.

  13. Drift tubes of Linac 2

    CERN Multimedia

    Photographic Service

    1977-01-01

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

  14. Rubens Flame-Tube Demonstration.

    Science.gov (United States)

    Ficken, George W.; Stephenson, Francis C.

    1979-01-01

    Investigates and explains the phenomenon associated with Rubens flame-tube demonstration, specifically the persistance of flames at regular intervals along the tube for few minutes after the gas is turned off. (GA)

  15. Prospects for stronger calandria tubes

    International Nuclear Information System (INIS)

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

    1990-12-01

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

  16. Expansion lyre-shaped tube

    International Nuclear Information System (INIS)

    Andro, Jean.

    1973-01-01

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

  17. Innovative phase shifter for pulse tube operating below 10 K

    Science.gov (United States)

    Duval, Jean-Marc; Charles, Ivan; Daniel, Christophe; André, Jérôme

    2016-09-01

    Stirling type pulse tubes are classically based on the use of an inertance phase shifter to optimize their cooling power. The limitations of the phase shifting capabilities of these inertances have been pointed out in various studies. These limitations are particularly critical for low temperature operation, typically below about 50 K. An innovative phase shifter using an inertance tube filled with liquid, or fluid with high density or low viscosity, and separated by a sealed metallic diaphragm has been conceived and tested. This device has been characterized and validated on a dedicated test bench. Operation on a 50-80 K pulse tube cooler and on a low temperature (below 8 K) pulse tube cooler have been demonstrated and have validated the device in operation. These developments open the door for efficient and compact low temperature Stirling type pulse tube coolers. The possibility of long life operation has been experimentally verified and a design for space applications is proposed.

  18. Development of a discharge-heated plasma tube

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Byung Heon; Jin, J. T.; Nam, S. M.; Lee, S. M.; Choi, H. L.; Ko, D. K.; Kim, S. H.; Lee, Y. B.; Choi, Y. S.; Lee, J. M.; Lee, C. K.; Lee, H. G.; Lee, H. C.; Jung, S. M.; Kim, Y. J.; Choi, G. S.; Son, N. G

    1999-12-01

    A discharge-heated type plasma tube was designed and constructed. The structure of the laser plasma tube was designed to be easy in maintenance. The inside plasma tube was made of a high purity alumina and the thermal insulator tube was made of a porous alumina. The electrode made of tungsten was chosen for the endurance of high discharge voltage. AR coated windows were used as laser windows. A proto-type laser plasma tube was tested with a pulse modulator. An average laser output power was 32 W at the discharge voltage of 28 kV, the electric input power of 4.6 kW, and the pulse repetition rates of 10 kHz. (author)

  19. NEI You Tube Videos: Amblyopia

    Science.gov (United States)

    ... NEI YouTube Videos: Amblyopia Listen NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia Animations Blindness Cataract Convergence Insufficiency Diabetic Eye Disease Dilated Eye Exam Dry Eye For Kids Glaucoma Healthy Vision Tips Leber Congenital Amaurosis Low ...

  20. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... NEI YouTube Videos: Amblyopia Listen NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia Animations Blindness Cataract Convergence Insufficiency Diabetic Eye Disease Dilated Eye Exam Dry Eye For Kids Glaucoma Healthy Vision Tips Leber Congenital Amaurosis Low ...

  1. Neutron image intensifier tubes

    International Nuclear Information System (INIS)

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

    1983-01-01

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

  2. 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.

  3. Fluting Modes in Transversely Nonuniform Solar Flux Tubes

    Science.gov (United States)

    Soler, Roberto

    2017-12-01

    Magnetohydrodynamic waves of different types are frequently observed in magnetic flux tubes of the solar atmosphere and are often modeled using simple models. In the standard flux tube model made of a straight uniform tube with an abrupt boundary, transverse wave modes are classified according to their azimuthal wavenumber, m. Sausage (m = 0) and kink (m = 1) modes produce pulsations of the cross section and transverse oscillations of tube axis, respectively. Both sausage and kink modes have been observed in the solar atmosphere. Fluting (m≥slant 2) modes produce perturbations that are essentially confined around the boundary of the tube, I.e., they have a strong surface-like character. Unlike sausage and kink modes, the detection of fluting modes remains elusive. Here we show that the inclusion of transverse inhomogeneity in the flux tube model dramatically affects the properties of fluting modes. Even in a thin tube, kink and fluting modes are no longer degenerate in frequency when the tube has a smooth boundary. In addition, fluting modes become heavily damped by resonant absorption in a timescale shorter than the oscillation period. The perturbations loose their global shape and their distinctive surface-like appearance. As a consequence of that, we argue that nonuniform flux tubes with smooth boundaries may not be able to support fluting-like perturbations as coherent, global modes.

  4. Corrosion and Rupture of Steam Generator Tubings in PWRs

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Seong Sik; Kim, Hong Pyo

    2007-08-15

    This report is intended to provide corrosion engineers in the filed of nuclear energy with information on the corrosion and rupture behavior of steam generator tubing in PWRs. Various types of corrosion in PWR steam generator tubing have been reported all around the world, and countermeasures such as the addition of corrosion inhibitors, a water chemistry control, a tube plugging and sleeving have been applied. Steam generators equipped with alloy 600 tubing, which are not so resistant to a stress corrosion cracking (SCC), have generally been replaced with new steam generators made of alloy 690 TT (Thermally treated). Pull tube examination results which were performed of KAERI are summarized. The tubes were affected by a pitting, SCC, and a denting. Nondestructive examination method for the tubes and repair techniques are also reviewed. In addition, the regulatory guidance of some countries are reviewed. As a part of a tube integrity project in Korea, some results on a tube rupture and leak behaviors for axial cracks are also mentioned.

  5. [Development of an Independent Heater for Ventilator Tube].

    Science.gov (United States)

    Liu, Ruhan; Wang, Guoyou

    2016-01-01

    Nowadays, normal humidifier is used to heat and humidify the gas before sending to ventilator tube. A new type of ventilator which offers both breathing tube with heater and humidifier is incorporate. In the light of this, patients already bought ventilator still confront this problem. Therefore, this paper mainly introduces a new manufactural method which is controlling the temperature and humidity of gas sent by breathing machine online by a temperature controller which consist of Silica gel hotline and microcomputer. As a matter of fact, the controller is adaptable in various types of breathing tube and can accurately control the humidity and temperature of gas sent into bodies.

  6. Should Children With Cleft Palate Receive Early Long-Term Tympanostomy Tubes: One Institution's Experience.

    Science.gov (United States)

    Shaffer, Amber D; Ford, Matthew D; Choi, Sukgi S; Jabbour, Noel

    2018-03-01

    To determine whether children with cleft palate might benefit from early long-term tympanostomy tubes with the hypothesis that receiving multiple tubes is associated with shorter duration of first tubes. Retrospective cohort study. Tertiary care children's hospital. Records from 401 consecutive children with cleft palate ± cleft lip, born April 2005 to April 2010, were reviewed. After exclusion of children with cleft repair at an outside hospital, no follow-up after 5 years of age, intact secondary palate, no tubes, or tube replacement at palatoplasty, 105 children remained. Number of tubes. Armstrong grommet tubes were placed at a median age of 6.7 months (range 2.3-19.6 months). Tubes were replaced in 55.3% of patients, with 34.0% receiving ≥3 sets. Duration of first tubes was significantly longer for children with 1 set of tubes compared with those with multiple sets (median 26 vs 19 months, P = .004). Otorrhea, but not perforation, was associated with longer duration of first tubes (median 27 vs 20.5 months, P = .028). Cleft type did not impact the proportion of patients with multiple tubes. Median age at last tube placement for children with multiple tubes was 5.0 years (range 1.9-8.7 years). Short duration of first tubes is associated with receiving multiple tubes. Because most patients require repeat tubes and many require tubes until school age, there is a significant need for controlled, prospective trials of early long-term tube placement in this population.

  7. Eddy Current Signature Classification of Steam Generator Tube Defects Using A Learning Vector Quantization Neural Network

    International Nuclear Information System (INIS)

    Garcia, Gabe V.

    2005-01-01

    A major cause of failure in nuclear steam generators is degradation of their tubes. Although seven primary defect categories exist, one of the principal causes of tube failure is intergranular attack/stress corrosion cracking (IGA/SCC). This type of defect usually begins on the secondary side surface of the tubes and propagates both inwards and laterally. In many cases this defect is found at or near the tube support plates

  8. Eddy Current Signature Classification of Steam Generator Tube Defects Using A Learning Vector Quantization Neural Network

    Energy Technology Data Exchange (ETDEWEB)

    Gabe V. Garcia

    2005-01-03

    A major cause of failure in nuclear steam generators is degradation of their tubes. Although seven primary defect categories exist, one of the principal causes of tube failure is intergranular attack/stress corrosion cracking (IGA/SCC). This type of defect usually begins on the secondary side surface of the tubes and propagates both inwards and laterally. In many cases this defect is found at or near the tube support plates.

  9. Experiments on vibration of heat exchanger tube arrays in cross flow

    International Nuclear Information System (INIS)

    Blevins, R.D.; Gibert, R.J.; Villard, B.

    1981-08-01

    A series of tests have been made at the Commissariat a l'Energie Atomique, in cooperation with General Atomic Company, SAN DIEGO (U.S.A.) on the flow-induced vibration of heat exchanger tube bundles in cross flow. These tests were made in air on tube bundles which simulated heat exchangers in the high temperature gas cooled reactors. The tests were of two types. In the first type, an instrumented tube was inserted at various locations into a tube bundle. Measurements were made of pressure at a number of points along the tube and about the circumference of the tube. These measurements were processed to obtain the spectra of turbulent pressure fluctuations on the tube, the spanwise correlation and the lift force. The second set of tests was made on tube bundles with flexible tubes. As the flow velocity was increased, these tests clearly show an instability. Nine tube configurations were tested with both plastic and metallic tubes and the effect of tube-to-tube difference in natural frequency was investigated

  10. A Role for YouTube in Telerehabilitation

    Directory of Open Access Journals (Sweden)

    M. Hunter Manasco

    2010-10-01

    Full Text Available YouTube is a free video sharing website that allows users to post and view videos. Although there are definite limitations in the applicability of this website to telerehabilitation, there are possible uses that should not be overlooked. Certain types of therapy, such as errorless learning therapy for certain language and cognitive deficits can be provided remotely via YouTube. In addition, negative emotional reactions to deficits are known to delay or halt recovery. The social networking capability YouTube provides enables individuals with health problems that may be unable to leave their houses an opportunity to gain valuable emotional support by meeting and communicating with others with similar problems. This article address the benefits and limitations of YouTube in the context of telerehabilitation and reports patient feedback on errorless learning therapy for aphasia delivered via videos posted on YouTube

  11. A Role for YouTube in Telerehabilitation.

    Science.gov (United States)

    Manasco, M Hunter; Barone, Nicholas; Brown, Amanda

    2010-01-01

    YouTube (http://youtube.com) is a free video sharing website that allows users to post and view videos. Although there are definite limitations in the applicability of this website to telerehabilitation, the YouTube technology offers potential uses that should not be overlooked. For example, some types of therapy, such as errorless learning therapy for certain language and cognitive deficits can be provided remotely via YouTube. In addition, the website's social networking capabilities, via the asynchronous posting of comments and videos in response to posted videos, enables individuals to gain valuable emotional support by communicating with others with similar health and rehabilitation challenges. This article addresses the benefits and limitations of YouTube in the context of telerehabilitation and reports patient feedback on errorless learning therapy for aphasia delivered via videos posted on YouTube.

  12. Test tube systems with cutting/recombination operations

    Energy Technology Data Exchange (ETDEWEB)

    Freund, R. [Technische Universitaet Wien (Austria); Csuhaj-Varju, E. [Computer and Automation Institute, Budapest (Hungary); Wachtler, F. [Universitaet Wien (Austria)

    1996-12-31

    We introduce test tube systems based on operations that are closely related to the splicing operations, i.e. we consider the operations of cutting a string at a specific site into two pieces with marking them at the cut ends and of recombining two strings with specifically marked endings. Whereas in the splicing of two strings these strings are cut at specific sites and the cut pieces are recombined immediately in a crosswise way, in CR(cutting/recombination)-schemes cutting can happen independently from recombining the cut pieces. Test tube systems based on these operations of cutting and recombination turn out to have maximal generative power even if only very restricted types of input filters for the test tubes are used for the redistribution of the contents of the test tubes after a period of cuttings and recombinations in the test tubes. 10 refs.

  13. Vortex Tube Modeling Using the System Identification Method

    Energy Technology Data Exchange (ETDEWEB)

    Han, Jaeyoung; Jeong, Jiwoong; Yu, Sangseok [Chungnam Nat’l Univ., Daejeon (Korea, Republic of); Im, Seokyeon [Tongmyong Univ., Busan (Korea, Republic of)

    2017-05-15

    In this study, vortex tube system model is developed to predict the temperature of the hot and the cold sides. The vortex tube model is developed based on the system identification method, and the model utilized in this work to design the vortex tube is ARX type (Auto-Regressive with eXtra inputs). The derived polynomial model is validated against experimental data to verify the overall model accuracy. It is also shown that the derived model passes the stability test. It is confirmed that the derived model closely mimics the physical behavior of the vortex tube from both the static and dynamic numerical experiments by changing the angles of the low-temperature side throttle valve, clearly showing temperature separation. These results imply that the system identification based modeling can be a promising approach for the prediction of complex physical systems, including the vortex tube.

  14. Incidence of Sinusitis Associated With Endotracheal and Nasogastric Tubes: NIS Database.

    Science.gov (United States)

    Metheny, Norma A; Hinyard, Leslie J; Mohammed, Kahee A

    2018-01-01

    Endotracheal and nasogastric tubes are recognized risk factors for nosocomial sinusitis. The extent to which these tubes affect the overall incidence of nosocomial sinusitis in acute care hospitals is unknown. To use data for 2008 through 2013 from the Nationwide Inpatient Sample database to compare the incidence of sinusitis in patients with nasogastric tubes with that in patients with an endotracheal tube alone or with both an endotracheal tube and a nasogastric tube. Patients' data with any of the following International Classification of Disease, Ninth Revision, Clinical Modification codes were abstracted from the database: (1) 96.6, enteral infusion of concentrated nutritional substances; (2) 96.07, insertion of other (naso-)gastric tube; or (3) 96.04, insertion of an endotracheal tube. Sinusitis was defined by the appropriate codes. Weighted and unweighted frequencies and weighted percentages were calculated, categorical comparisons were made by χ 2 test, and logistic regression was used to examine odds of sinusitis development by tube type. Of 1 141 632 included cases, most (68.57%) had an endotracheal tube only, 23.02% had a nasogastric tube only, and 8.41% had both types of tubes. Sinusitis was present in 0.15% of the sample. Compared with patients with only a nasogastric tube, the risk for sinusitis was 41% greater in patients with an endotracheal tube and 200% greater in patients with both tubes. Despite the low incidence of sinusitis, a significant association exists between sinusitis and the presence of an endotracheal tube, especially when a nasogastric tube is also present. ©2018 American Association of Critical-Care Nurses.

  15. Evaluation of reliability of EC inspection of VVER SG tubes

    International Nuclear Information System (INIS)

    Stanic, D.

    2001-01-01

    Evaluation of eddy current data collected during inspection of VVER steam generators is very complex task because of numerous parameters which have affect on eddy current signals. That was the reason that recently ago INETEC has started related scientific project in order to evaluate the reliability of eddy current (EC) inspection of VVER steam generator (SG) tubing. In the scope of project the following objectives will be investigated: 1. Determination of POD (Probability of detection) of various types degradation cracks, where their basic parameters are variables (basic parameters are depth, length, width, orientation, number) on three different sets of tubes (clean ideal tubes, tubes with pilgering, tubes electroplated with copper) 2. Sizing quality (accuracy, repeatability) (same data sets as defined in 1.) 3. Effect of fill factor on POD and sizing quality. 4. Effect of tube bends on POD and sizing quality. 5. Effect of other tube geometry variations on POD and sizing quality (tube ovality, transition zone region, expanded (rolled) part of tube, dents, dings). Investigation will start with bobbin probe technique which is the most used technique for general purpose VVER tube examination. Since INETEC is the only world company which successfully developed and applied rotating probe technique for VVER SG tubes, scope of the project will be extended on rotating probe technique utilizing 'pancake' and 'point' coil. Method reliability will be investigated first on the huge set of EDM notches representing various defect morphologies and simulating different factors, and the second part will be investigated on sets of degradation defects obtained by artificial corrosion. In the scope of the project the measures for enhancing the method reliability have to be determined. This considers the proper definition of parameters of examination system, as well as establishment of the suitable analysis procedures. This article presents the temporary results of the first part of

  16. Free compression tube. Applications

    Science.gov (United States)

    Rusu, Ioan

    2012-11-01

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

  17. Shock tube Multiphase Experiments

    Science.gov (United States)

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

    2017-11-01

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

  18. Explosively Bonded Gun Tube Liner Development

    Science.gov (United States)

    2015-04-01

    that waterjet cutting will be the best approach to rifling the tube due to cost considerations. This technology can be rated at an MRL of 3. If the...WA), which had experience cutting grooves in both metallic and ceramic materials, was awarded a Phase 1 SBIR to investigate the use of waterjet ... cutting to rifle the liner. Waterjet uses a stream of abrasive particles entrained in water to cut through many types of materials. The primary question

  19. Damping in heat exchanger tube bundles. A review

    International Nuclear Information System (INIS)

    Iqbal, Qamar; Khushnood, Shahab; Ghalban, Ali Roheim El; Sheikh, Nadeem Ahmed; Malik, Muhammad Afzaal; Arastu, Asif

    2007-01-01

    Damping is a major concern in the design and operation of tube bundles with loosely supported tubes in baffles for process shell and tube heat exchangers and steam generators which are used in nuclear, process and power generation industries. System damping has a strong influence on the amplitude of vibration. Damping depends upon the mechanical properties of the tube material, geometry of intermediate supports and the physical properties of shell-side fluid. Type of tube motion, number of supports, tube frequency, vibration amplitude, tube mass or diameter, side loads, support thickness, higher modes, shell-side temperature etc., affect damping in tube bundles. The importance of damping is further highlighted due to current trend of larger exchangers with increased shell-side velocities in modern units. Various damping mechanisms have been identified (Friction damping, Viscous damping, Squeeze film damping, Support damping. Two-Phase damping, and very recent-Thermal damping), which affect the performance of process exchangers and steam generators with respect to flow induced vibration design, including standard design guidelines. Damping in two-phase flow is very complex and highly void fraction, and flow-regime dependent. The current paper focuses on the various known damping mechanisms subjected to both single and two-phase cross-flow in process heat exchangers and steam generators and formulates the design guidelines for safer design. (author)

  20. Instrumented tube burns: theoretical and experimental observations

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-01-01

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

  1. Bacterial Biofilms in Jones Tubes.

    Science.gov (United States)

    Ahn, Eric S; Hauck, Matthew J; Kirk Harris, Jonathan; Robertson, Charles E; Dailey, Roger A

    To investigate the presence and microbiology of bacterial biofilms on Jones tubes (JTs) by direct visualization with scanning electron microscopy and polymerase chain reaction (PCR) of representative JTs, and to correlate these findings with inflammation and/or infection related to the JT. In this study, prospective case series were performed. JTs were recovered from consecutive patients presenting to clinic for routine cleaning or recurrent irritation/infection. Four tubes were processed for scanning electron microscopy alone to visualize evidence of biofilms. Two tubes underwent PCR alone for bacterial quantification. One tube was divided in half and sent for scanning electron microscopy and PCR. Symptoms related to the JTs were recorded at the time of recovery. Seven tubes were obtained. Five underwent SEM, and 3 out of 5 showed evidence of biofilms (60%). Two of the 3 biofilms demonstrated cocci and the third revealed rods. Three tubes underwent PCR. The predominant bacteria identified were Pseudomonadales (39%), Pseudomonas (16%), and Staphylococcus (14%). Three of the 7 patients (43%) reported irritation and discharge at presentation. Two symptomatic patients, whose tubes were imaged only, revealed biofilms. The third symptomatic patient's tube underwent PCR only, showing predominantly Staphylococcus (56%) and Haemophilus (36%) species. Two of the 4 asymptomatic patients also showed biofilms. All symptomatic patients improved rapidly after tube exchange and steroid antibiotic drops. Bacterial biofilms were variably present on JTs, and did not always correlate with patients' symptoms. Nevertheless, routine JT cleaning is recommended to treat and possibly prevent inflammation caused by biofilms.

  2. 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.

  3. Radiation-resistant camera tube

    International Nuclear Information System (INIS)

    Kuwahata, Takao; Manabe, Sohei; Makishima, Yasuhiro

    1982-01-01

    It was a long time ago that Toshiba launched on manufacturing black-and-white radiation-resistant camera tubes employing nonbrowning face-plate glass for ITV cameras used in nuclear power plants. Now in compliance with the increasing demand in nuclear power field, the Company is at grips with the development of radiation-resistant single color-camera tubes incorporating a color-stripe filter for color ITV cameras used under radiation environment. Herein represented are the results of experiments on characteristics of materials for single color-camera tubes and prospects for commercialization of the tubes. (author)

  4. 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…

  5. Advances in Valveless Piezoelectric Pump with Cone-shaped Tubes

    Science.gov (United States)

    Zhang, Jian-Hui; Wang, Ying; Huang, Jun

    2017-07-01

    This paper reviews the development of valveless piezoelectric pump with cone-shaped tube chronologically, which have widely potential application in biomedicine and micro-electro-mechanical systems because of its novel principles and deduces the research direction in the future. Firstly, the history of valveless piezoelectric pumps with cone-shaped tubes is reviewed and these pumps are classified into the following types: single pump with solid structure or plane structure, and combined pump with parallel structure or series structure. Furthermore, the function of each type of cone-shaped tubes and pump structures are analyzed, and new directions of potential expansion of valveless piezoelectric pumps with cone-shaped tubes are summarized and deduced. The historical argument, which is provided by the literatures, that for a valveless piezoelectric pump with cone-shaped tubes, cone angle determines the flow resistance and the flow resistance determines the flow direction. The argument is discussed in the reviewed pumps one by one, and proved to be convincing. Finally, it is deduced that bionics is pivotal in the development of valveless piezoelectric pump with cone-shaped tubes from the perspective of evolution of biological structure. This paper summarizes the current valveless piezoelectric pumps with cone-shaped tubes and points out the future development, which may provide guidance for the research of piezoelectric actuators.

  6. Predicting the need for nonstandard tracheostomy tubes in critically ill patients.

    Science.gov (United States)

    Pandian, Vinciya; Hutchinson, Christoph T; Schiavi, Adam J; Feller-Kopman, David J; Haut, Elliott R; Parsons, Nicole A; Lin, Jessica S; Gorbatkin, Chad; Angamuthu, Priya G; Miller, Christina R; Mirski, Marek A; Bhatti, Nasir I; Yarmus, Lonny B

    2017-02-01

    Few guidelines exist regarding the selection of a particular type or size of tracheostomy tube. Although nonstandard tubes can be placed over the percutaneous kit dilator, clinicians often place standard tracheostomy tubes and change to nonstandard tubes only after problems arise. This practice risks early tracheostomy tube change, possible bleeding, or loss of the airway. We sought to identify predictors of nonstandard tracheostomy tubes. In this matched case-control study at an urban, academic, tertiary care medical center, we reviewed 1220 records of patients who received a tracheostomy. Seventy-seven patients received nonstandard tracheostomy tubes (cases), and 154 received standard tracheostomy tubes (controls). Sex, endotracheal tube size, severity of illness, and computed tomography scan measurement of the distance from the trachea to the skin at the level of the superior aspect of the anterior clavicle were significant predictors of nonstandard tracheostomy tubes. Specifically, trachea-to-skin distance >4.4 cm and endotracheal tube sizes ≥8.0 were associated with nonstandard tracheostomy. The findings suggest that clinicians should consider using nonstandard tracheostomy tubes as the first choice if the patient is male with an endotracheal tube size ≥8.0 and has a trachea-to-skin distance >4.4 cm on the computed tomography scan. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Experimental and numerical studies of choked flow through adiabatic and diabatic capillary tubes

    International Nuclear Information System (INIS)

    Deodhar, Subodh D.; Kothadia, Hardik B.; Iyer, K.N.; Prabhu, S.V.

    2015-01-01

    Capillary tubes are extensively used in several cooling applications like refrigeration, electronic cooling etc. Local pressure variation in adiabatic straight capillary tube (mini channel) is studied experimentally and numerically with R134a as the working fluid. Experiments are performed on two straight capillary tubes. It is found that the diameter is the most sensitive design parameter of the capillary tube. Experiments are performed on five helically coiled capillary tubes to quantify the effect of pitch and curvature of helically coiled capillary tube on the pressure drop. Non dimensionalized factor to account coiling of capillary tube is derived to calculate mass flow rate in helically coiled capillary tubes. Flow visualization in adiabatic capillary tube confirms the bubbly nature of two phase flow. Numerical and experimental investigations in diabatic capillary tube suggest that the use of positive displacement pump and choking at the exit of the channel ensures flow stability. - Highlights: • Model is developed to design capillary tube in adiabatic and diabatic condition. • Effect of coil curvature on pressure drop is studied experimentally. • Correlation is developed to predict mass flow rate in helical capillary tubes. • Flow visualization is carried out to check the type of two phase flow. • Effect of choked flow on diabatic capillary tubes is studied experimentally.

  8. Tube to tube excursive instability - sensitivities and transients

    International Nuclear Information System (INIS)

    Brown, M.; Layland, M.W.

    1980-01-01

    A simple basic analysis of excursive instability in a boiler tube shows how it depends upon operating conditions and physical properties. A detailed mathematical model of an AGR boiler is used to conduct a steady state parameter sensitivity survey. It is possible from this basis to anticipate the effects of changes in operating conditions and changes in design parameters upon tube to tube stability. Dynamic responses of tubes operating near the stability threshold are examined using a mathematical model. Simulated excursions are triggered by imparting small abrupt pressure changes on the boiler inlet pressure. The influences of the magnitude of the pressure change, waterside friction factor and gas side coupling between tubes are examined. (author)

  9. 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.

  10. CFD simulations of heat transfer in internally helically ribbed tubes

    Directory of Open Access Journals (Sweden)

    Majewski Karol

    2016-06-01

    Full Text Available Heating surfaces in power boilers are exposed to very high heat flux. For evaporator protection against overheating, internally helically ribbed tubes are used. The intensification of the heat transfer and the maintenance of the thin water layer in the intercostal space, using ribbed tubes, enables better protection of the power boiler evaporator than smooth pipes. Extended inner surface changes flow and thermal conditions by influencing the linear pressure drop and heat transfer coefficient. This paper presents equations that are used to determine the heat transfer coefficient. The results of total heat transfer, obtained from CFD simulations, for two types of internally ribbed and plain tubes are also presented.

  11. A New Resonance Tube

    Science.gov (United States)

    Bates, Alan

    2017-12-01

    The measurement of the speed of sound in air with the resonance tube is a popular experiment that often yields accurate results. One approach is to hold a vibrating tuning fork over an air column that is partially immersed in water. The column is raised and lowered in the water until the generated standing wave produces resonance: this occurs at the point where sound is perceived to have maximum loudness, or at the point where the amplitude of the standing wave has maximum value, namely an antinode. An antinode coincides with the position of the tuning fork, beyond the end of the air column, which consequently introduces an end correction. One way to minimize this end correction is to measure the distance between consecutive antinodes.

  12. 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.

  13. Pressure tube reactor

    International Nuclear Information System (INIS)

    Matsumoto, Tomoyuki; Fujino, Michihira.

    1980-01-01

    Purpose: To equalize heavy water flow distribution by providing a nozzle for externally injecting heavy water from a vibration preventive plate to the upper portion to feed the heavy water in a pressure tube reactor and swallowing up heavy water in a calandria tank to supply the heavy water to the reactor core above the vibration preventive plate. Constitution: A moderator injection nozzle is mounted on the inner wall of a calandria tank. Heavy water is externally injected above the vibration preventive plate, and heavy water in the calandria tank is swallowed up to supply the heavy water to the core reactor above the vibration preventive plate. Therefore, the heavy water flow distribution can be equalized over the entire reactor core, and the distribution of neutron absorber dissolved in the heavy water is equalized. (Yoshihara, H.)

  14. 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.

  15. SPIRAL COUNTER-CURRENT CHROMATOGRAPHY OF SMALL MOLECULES, PEPTIDES AND PROTEINS USING THE SPIRAL TUBING SUPPORT ROTOR

    OpenAIRE

    Knight, Martha; Finn, Thomas M.; Zehmer, John; Clayton, Adam; Pilon, Aprile

    2011-01-01

    An important advance in countercurrent chromatography (CCC) carried out in open flow-tubing coils, rotated in planetary centrifuges, is the new design to spread out the tubing in spirals. More spacing between the tubing was found to significantly increase the stationary phase retention, such that now all types of two-phase solvent systems can be used for liquid-liquid partition chromatography in the J-type planetary centrifuges. A spiral tubing support (STS) frame with circular channels was c...

  16. TJC: plan and prepare for the transition to new tubing connectors to minimize the risk of dangerous misconnections, clinician frustration.

    Science.gov (United States)

    2014-12-01

    To reduce the risk of dangerous tubing misconnections, the ISO is rolling out new tubing connector standards that will eventually make it nearly impossible for tubing associated with one delivery system to be connected to a delivery system that serves a different purpose. Experts welcome the change, noting that tubing misconnections that cause injury and even death have been happening for years. However, TJC has issued a Sentinel Event Alert, warning that health care organizations need to be vigilant in managing the risk posed by these misconnections during the phased-in transition to the new connectors. Experts explain that tubing misconnections occur because many different types of tubing utilize the same Leur connector, making it possible for a clinician to mistakenly connect a tube to the wrong delivery system. The most common type of tubing misconnection reported to the ISMP is when a clinician wants to administer something to a patient through a feeding tube, but accidently administers the substance through an IV tube instead. The first new connector, called the ENFit, is going to be for enteral feeding tubes. It will not connect to IV tubing, making that type of misconnection unlikely. The new connector should be available early next year. Since hospitals will continue to use older tubing until their supplies are exhausted, manufacturers will temporarily provide adapters capable of making new administration sets compatible with older tubing.

  17. The root caused analysis of leakaged heat exchanger tube; Ursachenanalyse einer Leckage an einem Waermeuebertraegerrohr

    Energy Technology Data Exchange (ETDEWEB)

    Shamsudin, Shaiful Rizam; Salleh, M.A.A. Mohd; Rahmat, Azmi; Anuar, Mohd Arif [Universiti Malaysia Perlis (UniMAP) (Malaysia). Center of Excellence Geopolymer and Green Technology (CEGeoGTech); Harun, Mohd; Zayid, Hafizal [Malaysian Nuclear Agency, Selangor (Malaysia). Industry Technology Div.; Noor, Mazlee Mohd [Universiti Malaysia Perlis (UniMAP) (Malaysia). School of Materials Engineering

    2015-05-01

    AISI type 316L stainless steel was used as a heat exchanger tube material in an inter-cooler column. After less than a year of operation, severe corrosion failures occurred and a transverse opening leakage was observed on one of the heat exchanger tubes. The failed tube was carefully analyzed using various metallurgical laboratory equipments. The root cause of the tube leakage was believed due to the presence of horizontal micro and macro pores as a hydrogen gas entrapment during casting of the parent ingot. The overlapped and gaping pores formed notch on the shell side of the tube surface, and it increasingly evident when the use of a high-energy water-jet and metal brush as cleaning procedure results in an establishment of pitting type local-action corrosion cells penetrated the tube wall. As a result, corrosive fluid in the tube side dissolved into the cooling water, accelerating the corrosion process.

  18. Carcinome du tube collecteur de Bellini: une nouvelle observation ...

    African Journals Online (AJOL)

    Le carcinome du tube collecteur de Bellini est un type très rare des carcinomes à cellules rénales (CCR), sa fréquence est inférieure à 1%. Il dérive de la partie distale du néphron, plus précisément du tube collecteur. Ses aspects morphologiques sont extrêmement variables, rendant son diagnostic difficile. Nous rapportons ...

  19. A Role for YouTube in Telerehabilitation

    OpenAIRE

    Manasco, M. Hunter; Barone, Nicholas; Brown, Amanda

    2010-01-01

    YouTube is a free video sharing website that allows users to post and view videos. Although there are definite limitations in the applicability of this website to telerehabilitation, there are possible uses that should not be overlooked. Certain types of therapy, such as errorless learning therapy for certain language and cognitive deficits can be provided remotely via YouTube. In addition, negative emotional reactions to deficits are known to delay or halt recovery. The social networking cap...

  20. Hydro-osmotic Instabilities in Active Membrane Tubes

    Science.gov (United States)

    Al-Izzi, Sami C.; Rowlands, George; Sens, Pierre; Turner, Matthew S.

    2018-03-01

    We study a membrane tube with unidirectional ion pumps driving an osmotic pressure difference. A pressure-driven peristaltic instability is identified, qualitatively distinct from similar tension-driven Rayleigh-type instabilities on membrane tubes. We discuss how this instability could be related to the function and biogenesis of membrane bound organelles, in particular, the contractile vacuole complex. The unusually long natural wavelength of this instability is in agreement with that observed in cells.

  1. 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,

  2. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... Amaurosis Low Vision Refractive Errors Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded video for NEI YouTube Videos: Amblyopia NEI Home Contact Us A-Z Site Map NEI on Social Media Information in Spanish (Información en español) Website, ...

  3. Automated Identification and Reconstruction of YouTube Video Access

    Directory of Open Access Journals (Sweden)

    Jonathan Patterson

    2012-06-01

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

  4. 27 CFR 40.352 - Cigarette tubes.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Cigarette tubes. 40.352... OF THE TREASURY (CONTINUED) TOBACCO MANUFACTURE OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND PROCESSED TOBACCO Manufacture of Cigarette Papers and Tubes Taxes § 40.352 Cigarette tubes. Cigarette tubes...

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

    International Nuclear Information System (INIS)

    Lemoine, Th.

    2009-01-01

    This article gives an overview of the basic technologies of electronic tubes: cathodes, electronic optics, vacuum and high voltage. Then the grid tubes, klystrons and inductive output tubes (IOT) are introduced. Content: 1 - context and classification; 2 - electronic tube technologies: cathodes, electronic optics, magnetic confinement (linear tubes), periodic permanent magnet (PPM) focussing, collectors, depressed collectors; 3 - vacuum technologies: vacuum quality, surface effects and interaction with electrostatic and RF fields, secondary emission, multipactor effect, thermo-electronic emission; 4 - grid tubes: operation of a triode, tetrodes, dynamic operation and classes of use, 'common grid' and 'common cathode' operation, ranges of utilisation and limitations, operation of a tetrode on unadjusted load, lifetime of a tetrode, uses of grid tubes; 5 - klystrons: operation, impact of space charge, multi-cavity klystrons, interaction efficiency, extended interaction klystrons, relation between interaction efficiency, perveance and efficiency, ranges of utilization and power limitations, multi-beam klystrons and sheet beam klystrons, operation on unadjusted load, klystron band pass and lifetime, uses; 6 - IOT: principle of operation, ranges of utilisation and limitations, interaction efficiency and depressed collector IOT, IOT lifetime and uses. (J.S.)

  6. Pulsed Drift Tube Accelerator

    International Nuclear Information System (INIS)

    Faltens, A.

    2004-01-01

    The pulsed drift-tube accelerator (DTA) concept was revived by Joe Kwan and John Staples and is being considered for the HEDP/WDM application. It could be used to reach the full energy or as an intermediate accelerator between the diode and a high gradient accelerator such as multi-beam r.f. In the earliest LBNL HIF proposals and conceptual drivers it was used as an extended injector to reach energies where an induction linac with magnetic quadrupoles is the best choice. For HEDP, because of the very short pulse duration, the DTA could provide an acceleration rate of about 1MV/m. This note is divided into two parts: the first, a design based on existing experience; the second, an optimistic extrapolation. The first accelerates 16 parallel K + beams at a constant line charge density of 0.25(micro) C/m per beam to 10 MeV; the second uses a stripper and charge selector at around 4MeV followed by further acceleration to reach 40 MeV. Both benefit from more compact sources than the present 2MV injector source, although that beam is the basis of the first design and is a viable option. A pulsed drift-tube accelerator was the first major HIF experiment at LBNL. It was designed to produce a 2(micro)s rectangular 1 Ampere C s + beam at 2MeV. It ran comfortably at 1.6MeV for several years, then at lower voltages and currents for other experiments, and remnants of that experiment are in use in present experiments, still running 25 years later. The 1A current, completely equivalent to 1.8A K + , was chosen to be intermediate between the beamlets appropriate for a multi-beam accelerator, and a single beam of, say, 10A, at injection energies. The original driver scenarios using one large beam on each side of the reactor rapidly fell out of favor because of the very high transverse and longitudinal fields from the beam space charge, circa 1MV/cm and 250 kV/cm respectively, near the chamber and because of aberrations in focusing a large diameter beam down to a 1mm radius spot at a

  7. Conditioning and breakdown phenomena in accelerator tubes

    International Nuclear Information System (INIS)

    Skorka, S.J.

    1979-01-01

    Important breakdown mechanisms in accelerator tubes are reviewed, and discharge phenomena in NEC tubes are deduced from the surface appearance of the electrodes and insulators of a used tube. Microphotos of these surfaces are shown

  8. Eddy current signal comparison for tube identification

    Science.gov (United States)

    Glass, S. W.; Vojvodic, R.

    2015-03-01

    Inspection of nuclear power plant steam generator tubes is required to justify continued safe plant operation. The steam generators consist of thousands of tubes with nominal diameters of 15 to 22mm, approximately 1mm wall thickness, and 20 to 30m in length. The tubes are inspected by passing an eddy current probe through the tubes from tube end to tube end. It is critical to know exactly which tube identification (row and column) is associated with each tube's data. This is controlled by a precision manipulator that provides the tube ID to the eddy current system. Historically there have been some instances where the manipulator incorrectly reported the tube ID. This can have serious consequences including lack of inspection of a tube, or if a pluggable indication is detected, the tube is likely to be mis-plugged thereby risking a primary to secondary leak.

  9. Some Observations on Carbon Nano tubes Susceptibility to Cell Phagocytosis

    International Nuclear Information System (INIS)

    Fraczek-Szczypta, A.; Menaszek, E.; Blazewicz, S.; Menaszek, E.

    2011-01-01

    The aim of this study was to assess the influence of different types of carbon nano tubes (CNTs) on cell phagocytosis. Three kinds of carbon nano tubes: single-walled carbon nano horns (SWCNHs), multi walled carbon nano tubes (MWCNTs), and ultra-long single-walled carbon nano tubes (ULSWCNTs) before and after additional chemical functionalization were seeded with macrophage cell culture. Prior to biological testing, the CNTs were subjected to dispersion process with the use of phosphate buffered solution (PBS) and PBS containing surfactant (Tween 20) or dimethyl sulfoxide (DMSO). The results indicate that the cells interaction with an individual nano tube is entirely different as compared to CNTs in the form of aggregate. The presence of the surfactant favors the CNTs dispersion in culture media and facilitates phagocytosis process, while it has disadvantageous influence on cells morphology. The cells phagocytosis is a more effective for MWCNTs and SWCNHs after their chemical functionalization. Moreover, these nano tubes were well dispersed in culture media without using DMSO or surfactant. The functionalized carbon nano tubes were easily dispersed in pure PBS and seeded with cells

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

    International Nuclear Information System (INIS)

    Splichal, K.; Otruba, J.; Keilova, E.; Krhounek, V.; Turek, J.

    1996-01-01

    The leakage and plugging limits were derived for WWER steam generators based on leak and burst tests using tubes with axial part-through and through-wall defects. The following conclusions were arrived at: (i) The permissible primary-to-secondary leak rate with respect to the permissible through-wall defect size of WWER-440 and WWER-1000 steam generator tubes is 8 l/h. (ii) The primary-to-secondary leak rate is reduced by the blocking of the tube cracks by corrosion product particles and other substances. (iii) The rate of crack penetration through the tube wall is higher than the crack widening. (iv) The validity of the criterion of instability for tubes with through-wall cracks was confirmed experimentally. For the WWER-440 and WWER-1000 steam generators, the critical size of axial through-wall cracks, for the threshold primary-to-secondary pressure difference, is 13.8 and 12.0 mm, respectively. (v) The calculated leakage for the rupture of one tube and for the assumed extreme defects is two orders and one order of magnitude, respectively, higher than the proposed primary water leakage limit of 8 l/h. (vi) The experiments gave evidence that the use of the permissible thinning limit of 80% for the heat exchange tube plugging does not bring about uncontrollable leakage or unstable crack growth. This is consistent with experience gained at WWER-440 type nuclear power plants. 4 tabs., 5 figs., 9 refs

  11. mouseTube

    Science.gov (United States)

    Torquet, Nicolas; de Chaumont, Fabrice; Faure, Philippe; Bourgeron, Thomas; Ey, Elodie

    2016-01-01

    Ultrasonic vocalisation is a broadly used proxy to evaluate social communication in mouse models of neuropsychiatric disorders. The efficacy and robustness of testing these models suffer from limited knowledge of the structure and functions of these vocalisations as well as of the way to analyse the data. We created mouseTube , an open database with a web interface, to facilitate sharing and comparison of ultrasonic vocalisations data and metadata attached to a recording file. Metadata describe 1) the acquisition procedure, e.g ., hardware, software, sampling frequency, bit depth; 2) the biological protocol used to elicit ultrasonic vocalisations; 3) the characteristics of the individual emitting ultrasonic vocalisations ( e.g. , strain, sex, age). To promote open science and enable reproducibility, data are made freely available. The website provides searching functions to facilitate the retrieval of recording files of interest. It is designed to enable comparisons of ultrasonic vocalisation emission between strains, protocols or laboratories, as well as to test different analysis algorithms and to search for protocols established to elicit mouse ultrasonic vocalisations. Over the long term, users will be able to download and compare different analysis results for each data file. Such application will boost the knowledge on mouse ultrasonic communication and stimulate sharing and comparison of automatic analysis methods to refine phenotyping techniques in mouse models of neuropsychiatric disorders.

  12. X-ray tube

    International Nuclear Information System (INIS)

    Mayo, B.J.

    1980-01-01

    An x-ray tube in which the x-ray origin is scanned on a circle around the patient, comprises a ring-shaped anode, an electron beam travelling along a circular path being deflected onto the anode at the desired positions. The electron beam path may be in a plane parallel to the anode and perhaps at the same radius. It may be in the same plane as a transmission target/anode and at a greater radius. The anode should extend over at least 180 0 although it may extend to 360 0 . Electrostatic means may be provided to constrain the beam to the circular path and further electrostatic means deflect it to the anode of the beam and ensure it is focused at the point of incidence. Collimators provide a planar fan-shaped beam and the anode may be shaped to attenuate side lobes of the radiation. Electrode collects electrons not deflected. The focal regions may be adjacent or otherwise. Coils may provide periodic focusing to overcome space charge dispersion and dynamic adjustment of the focusing before deflection ensures focusing at target incidence. Focusing may be absent near the deflection region, and current in the coil section near the focal region should be zero. (author)

  13. Three-in-one resonance tube for harmonic series sound wave experiments

    Science.gov (United States)

    Jaafar, Rosly; Nazihah Mat Daud, Anis; Ali, Shaharudin; Kadri Ayop, Shahrul

    2017-07-01

    In this study we constructed a special three-in-one resonance tube for a harmonic series sound waves experiment. It is designed for three different experiments: both-open-end, one-closed-end and both-closed-end tubes. The resonance tube consists of a PVC conduit with a rectangular hole, rubber tube, plastic stopper with an embedded microphone and a plastic stopper. The resonance tube is utilized with visual analyser freeware to detect, display and measure the resonance frequencies for each harmonic series. The speeds of sound in air, v, are determined from the gradient of the 2(L+e) versus n fn-1 , 4(L+e) versus n fn-1 and 2L versus n fn-1 graphs for both-open-end, one-closed-end and both-closed-end tubes, respectively. The compatibility of a resonance tube for a harmonic series experiment is determined by comparing the experimental and standard values of v. The use of a resonance tube produces accurate results for v within a 1.91% error compared to its standard value. It can also be used to determine the values of end correction, e, in both-open-end and one-closed-end tubes. The special resonance tube can also be used for the values of n for a harmonic series experiment in the three types of resonance tubes: both-open-end, one-closed-end and both-closed-end tubes.

  14. Molecular pathogenesis of serous Fallopian tube and ovarian carcinoma

    NARCIS (Netherlands)

    Nowee, M.E.

    2009-01-01

    Serous type Fallopian tube carcinoma (FTC) and ovarian carcinoma (OVCA) are gynaecological malignancies with a poor prognosis. Although most of the encountered tumours are sporadic, a positive family history is an important risk factor. Both tumour types have been linked to mutations in the BRCA1

  15. 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.

  16. Rigid inflatable gastrostomy tube malposition

    Directory of Open Access Journals (Sweden)

    Timothy E. Murray, MB, MCh, MRCS, FFR

    2017-12-01

    Full Text Available Rigid inflatable gastrostomy (RIG tubes are widely used in contemporary clinical practice for a variety of indications. Insertion of RIG tubes is associated with a high technical success rate and low incidence of mortality. In this case report, a procedural pitfall associated with intraperitoneal-extragastric malposition is described. Rigorous assessment of abdominal radiographs, as well as awareness of the expected appearance of the RIG tube and gastropexy T-fasteners, allows the abdominal radiologist to detect early RIG position in the early postprocedural period. Abdominal radiography is a widely available and inexpensive technique. The high spatial resolution it provides makes it a valuable tool in determining hardware position.

  17. Expansion tube test time predictions

    Science.gov (United States)

    Gourlay, Christopher M.

    1988-01-01

    The interaction of an interface between two gases and strong expansion is investigated and the effect on flow in an expansion tube is examined. Two mechanisms for the unsteady Pitot-pressure fluctuations found in the test section of an expansion tube are proposed. The first mechanism depends on the Rayleigh-Taylor instability of the driver-test gas interface in the presence of a strong expansion. The second mechanism depends on the reflection of the strong expansion from the interface. Predictions compare favorably with experimental results. The theory is expected to be independent of the absolute values of the initial expansion tube filling pressures.

  18. Operative behaviour of a condenser tube under ETA chemistry

    International Nuclear Information System (INIS)

    Chocron, Mauricio; Burkart, Arturo; Rodriguez, Ivanna; Raul, Manera; Diego, Quinteros

    2012-09-01

    Among the various recommendations for the surveillance of the integrity of the materials of the Secondary Cycle (Balance of Plant) it is the periodic removal of a steam generator tube and a condenser tube and their analysis. It considers assessment of the water chemistry, corrosion and the reciprocal effect on or from other components of the cycle. Embalse N.P.P. is a CANDU 6 type, Pressurized Heavy Water Reactor, located in Cordoba Province, Argentina. Previous papers have shown results on tubes removed from the steam generators (Bordoni et al., NPC'08, September 15-18, 2008, Berlin, Germany; 6 th Canadian Nuclear Society - Steam Generators Conference, November 8-11, 2009, Toronto, Canada). Considering that the Embalse BOP has mixed metallurgy, i.e., steam generator tubes made of A800, piping made of ferrous alloys and condenser tubes made of Admiralty Brass and also taking into account that the chemistry has been modified from Morpholine control to ETA control (Fernandez et. al, NPC'2010, October 3-7, Quebec City, Canada), it has been decided to remove and analyze a condenser tube that has been placed in operation coincidently with the establishment of the ETA chemical control. The extraction is dated along with the November 2011 Plant Programmed Outage. Objectives are assessing the operative behavior of the tube performing visual and optical microscope inspection, SEM analysis of the oxides and deposits in exposed surfaces and occluded locations like tube sheet and other tests as well. Results are compared to the same analysis performed on a new tube in storage and integrated with the chemical operative figures of the cycle during the period: chemical data and corrosion products transport. (authors)

  19. Overview of steam generator tube degradation and integrity issues

    International Nuclear Information System (INIS)

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

    1996-10-01

    The degradation of steam generator tubes in pressurized water nuclear reactors continues to be a serious problem. Primary water stress corrosion cracking is commonly observed at the roll transition zone at U-bends, at tube denting locations, and occasionally in plugs and sleeves. Outer-diameter stress corrosion cracking and intergranular attack commonly occur near the tube support plate crevice, near the tube sheet in crevices or under sludge piles, and occasionally in the free span. A particularly troubling recent trend has been the increasing occurrence of circumferential cracking at the RTZ on both the primary and secondary sides. Segmented axial cracking at the tubes support plate crevices is also becoming more common. Despite recent advances in in-service inspection technology, a clear need still exists for quantifying and improving the reliability of in- service inspection methods with respect to the probability of detection of the various types of flaws and their accurate sizing. Improved inspection technology and the increasing occurrence of such degradation modes as circumferential cracking, intergranular attack, and discontinuous axial cracking have led to the formulation of a new performance-based steam generator rule. This new rule would require the development and implementation of a steam generator management program that monitors tube condition against accepted performance criteria to ensure that the tubes perform the required safety function over the next operating cycle. The new steam generator rule will also be applied to severe accident conditions to determine the continued serviceability of a steam generator with degraded tubes in the event of a severe accident. Preliminary analyses are being performed for a hypothetical severe accident scenario to determine whether failure will occur first in the steam generator tubes, which would lead to containment bypass, or instead in the hot leg nozzle or surge line, which would not

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

    International Nuclear Information System (INIS)

    Habert, M.

    2009-04-01

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

  1. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... and Aging Program African American Program Training and Jobs Fellowships NEI Summer Intern Program Diversity In Vision ... DIVRO) Student Training Programs To search for current job openings visit HHS USAJobs Home >> NEI YouTube Videos >> ...

  2. 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.

  3. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... and Aging Program African American Program Training and Jobs Fellowships NEI Summer Intern Program Diversity In Vision ... DIVRO) Student Training Programs To search for current job openings visit HHS USAJobs Home > NEI YouTube Videos > ...

  4. 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.

  5. 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 ...

  6. Conditioning of NEC accelerator tubes

    International Nuclear Information System (INIS)

    Yntema, J.L.

    1979-01-01

    The conditioning process of NEC tubes was investigated by recording the fluctuations observed with a residual gas analyzer for a fixed mass and a simultaneous recording of the current fluctuations in background pressure

  7. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... Disease Education Program Glaucoma Education Program Low Vision Education Program Hispanic/Latino ... To search for current job openings visit HHS USAJobs Home » NEI YouTube ...

  8. Adjustable rare earth quadrupole drift tube magnets

    International Nuclear Information System (INIS)

    Feinberg, B.; Tanabe, J.; Halbach, K.; Koehler, G.; Green, M.I.

    1987-03-01

    A prototype permanent-magnet drift tube quadrupole with adjustable field strength has been constructed and tested. The magnet uses iron pole pieces to provide the required field shape along with rare earth permanent-magnet material (samarium cobalt) to energize the magnet. A unique feature of the configuration is the adjustability of the field, accomplished by rotating the outer rings consisting of permanent magnets and iron. In contrast with a previous prototype magnet, this new design uses ball bearings in place of slide bearings to eliminate potential failures. The rotation is now achieved with a bevel gear mechanism. The prototype design also incorporates a new drift tube shell vacuum seal to allow easy disassembly. Tests were made of the magnetic properties and the mechanical performance of this magnet. Field errors are extremely small, and the magnet passed an accelerated ten year lifetime test. It is planned to use this type of magnet to replace 24 of the SuperHILAC prestripper drift tubes

  9. Theoretical-experimental assessment of the variables affecting fretting of Atucha I nuclear power plant utility steam generators tubes

    International Nuclear Information System (INIS)

    Kulichevsky, Raul M.

    1995-01-01

    Fretting wear of Steam Generator tubes caused by flow induced vibrations generates uncertainty on their integrity. The knowledge of the controlling variables of the wear process may give a criterion to evaluate the tubes residual life. Information on vibratory response and dynamic interaction between tubes and their supports are prerequisites for understanding the relationship between fretting wear and tube vibration. Experimental results of the vibratory response of an Atucha-I nuclear power plant type U-tube, the influence of tube/support clearance on this response and a study of tube/support dynamic interaction, which allow the verification of a finite element model of this type of tubes, are presented in this work. Also wear results for the Incoloy 800/DIN 1.4550 austenitic stainless steel pair of materials and a first evaluation of the wear constant of this pair are presented. (author)

  10. Eddy current tube testing unit

    International Nuclear Information System (INIS)

    Dufayet, J.P.; Duret, G.

    1975-01-01

    The unit described can check a wide variety of tubes in quick succession and its modular design gives it a high degree of versability. Suitably defined working conditions and specific fittings enable most of the faults encountered in the manufacture of a tube to be detected. By appropriate means of selection based on signal amplitude, phase and frequency analyses it is possible to adapt selection criteria to the seriousness of the different categories of defect [fr

  11. Electronics for proportional drift tubes

    International Nuclear Information System (INIS)

    Fremont, G.; Friend, B.; Mess, K.H.; Schmidt-Parzefall, W.; Tarle, J.C.; Verweij, H.; CERN-Hamburg-Amsterdam-Rome-Moscow Collaboration); Geske, K.; Riege, H.; Schuett, J.; CERN-Hamburg-Amsterdam-Rome-Moscow Collaboration); Semenov, Y.; CERN-Hamburg-Amsterdam-Rome-Moscow Collaboration)

    1980-01-01

    An electronic system for the read-out of a large number of proportional drift tubes (16,000) has been designed. This system measures deposited charge and drift-time of the charge of a particle traversing a proportional drift tube. A second event can be accepted during the read-out of the system. Up to 40 typical events can be collected and buffered before a data transfer to a computer is necessary. (orig.)

  12. The YouTube reader

    OpenAIRE

    Snickars, Pelle; Vonderau, Patrick

    2009-01-01

    YouTube has come to epitomize the possibilities of digital culture. With more than seventy million unique users a month and approximately eighty million videos online, this brand-name video distribution platform holds the richest repository of popular culture on the Internet. As the fastest growing site in the history of the Web, YouTube promises endless new opportunities for amateur video, political campaigning, entertainment formats, and viral marketing—a clip culture that has seemed to out...

  13. Multiphysics Numerical Modeling of a Fin and Tube Heat Exchanger

    DEFF Research Database (Denmark)

    Singh, Shobhana; Sørensen, Kim; Condra, Thomas Joseph

    2015-01-01

    In the present research work, a modeling effort to predict the performance of a liquid-gas type fin and tube heat exchanger design is made. Three dimensional (3D) steady state numerical model is developed using commercial software COMSOL Multiphysics based on finite element method (FEM). For the ......In the present research work, a modeling effort to predict the performance of a liquid-gas type fin and tube heat exchanger design is made. Three dimensional (3D) steady state numerical model is developed using commercial software COMSOL Multiphysics based on finite element method (FEM...

  14. The influence of chest tube size and position in primary spontaneous pneumothorax

    DEFF Research Database (Denmark)

    Riber, Sara S.; Riber, Lars P S; Olesen, Winnie H.

    2017-01-01

    patients admitted with PSP over a 5-year period. Traumatic, iatrogenic and secondary pneumothoraxes were excluded. Gender, age, smoking habits, type and size of chest tube used (pigtail catheter or surgical chest tube) were recorded from the patients' charts. All chest X-rays upon admittance......Background: Optimal chest tube position in the pleural cavity is largely unexplored for the treatment of primary spontaneous pneumothorax (PSP). We investigated whether type, size and position of chest tubes influenced duration of treatment for PSP. Methods: A retrospective follow-up study of all...... and immediately following chest tube placement were retrieved and re-evaluated for size of pneumothorax (categorized into five groups) and location of the chest tube tip (categorized as upper, middle or lower third of the pleural cavity). All data were analysed in a Cox proportional hazards regression model...

  15. Development and performance of resistive seamless straw-tube gas chambers

    International Nuclear Information System (INIS)

    Takubo, Y.; Aoki, M.; Ishihara, A.; Ishii, J.; Kuno, Y.; Maeda, F.; Nakahara, K.; Nosaka, N.; Sakamoto, H.; Sato, A.; Terai, K.; Igarashi, Y.; Yokoi, T.

    2005-01-01

    A new straw-tube gas chamber which is made of seamless straw-tubes, instead of ordinary wound-type straw-tubes is developed. Seamless straw-tubes have various advantages over ordinary wound-type ones, in particular, in terms of mechanical strength and lesser wall thickness. Our seamless straw-tubes are fabricated to be resistive so that the hit positions along the straw axis can be read by cathode planes placed outside the straw-tube chambers, where the cathode strips run transverse to the straw axis. A beam test was carried out at KEK to study their performance. As a result of the beam test, the position resolution of the cathode strips of 220μm is achieved, and an anode position resolution of 112μm is also obtained

  16. Multi-anode wire straw tube tracker

    International Nuclear Information System (INIS)

    Oh, S.H.; Ebenstein, W.L.; Wang, C.W.

    2011-01-01

    We report on a test of a straw tube detector design having several anode (sense) wires inside a straw tube. The anode wires form a circle inside the tube and are read out independently. This design could solve several shortcomings of the traditional single wire straw tube design such as double hit capability and stereo configuration.

  17. 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 tube is a device consisting of a hollow copper tube intended to take an impression of a single tooth... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Impression tube. 872.6570 Section 872.6570 Food...

  18. 27 CFR 41.35 - Cigarette tubes.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Cigarette tubes. 41.35... OF THE TREASURY (CONTINUED) TOBACCO IMPORTATION OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND PROCESSED TOBACCO Taxes Tax Rates § 41.35 Cigarette tubes. Cigarette tubes are taxed at the following rates...

  19. Tubing vs. buckets: a cost comparison

    Science.gov (United States)

    Neil K. Huyler

    1975-01-01

    Equipment investment for tubing-vacuum systems was significantly less than that for bucket systems. Tubing-vacuum systems required about 22 percent less labor input, the major labor input being completed before sap-flow periods. Annual cost of operation was less for tubing-vacuum than the bucket system. Small tubing-vacuum operations showed more profit potential than...

  20. Development of a sealing process of capsules for surveillance test tubes of the vessel in nuclear power plants; Desarrollo de proceso de sellado de capsulas para probetas de vigilancia de la vasija en nucleoelectricas

    Energy Technology Data Exchange (ETDEWEB)

    Romero C, J.; Fernandez T, F.; Perez R, N.; Rocamontes A, M.; Garcia R, R. [ININ, Km 36.5 Carretera Mexico-Toluca, 52750 La Marquesa, Estado de Mexico (Mexico)

    2007-07-01

    The surveillance capsule is composed by the support, three capsules for impact test tubes, five capsules for tension test tubes and one porta dosemeters. The capsules for test tubes are of two types: rectangular capsule for Charpy test tubes and cylindrical capsule for tension test tubes. This work describes the development of the welding system to seal the capsules for test tubes that should contain helium of ultra high purity to a pressure of 1 atmosphere. (Author)

  1. Steam generator tube fitness-for-service guidelines

    International Nuclear Information System (INIS)

    Gorman, J.A.; Harris, J.E.; Lowenstein, D.B.

    1995-07-01

    The objectives of this project were to characterize defect mechanisms which could affect the integrity of steam generator tubes, to review and critique state-of-the-art Canadian and international steam generator tube fitness-for-service criteria and guidelines, and to obtain recommendations for criteria that could be used to assess fitness-for service guidelines for steam generator tubes containing defects in Canadian power plant service. Degradation mechanisms, that could affect CANDU steam generator tubes in Canada, have been characterized. The design standards and safety criteria that apply to steam generator tubing in nuclear power plant service in Canada and in Belgium, France, Japan, Spain, Sweden, and the USA have been reviewed and described. The fitness-for-service guidelines used for a variety of specific defect types in Canada and internationally have been evaluated and described in detail in order to highlight the considerations involved in developing such defect specific guidelines. Existing procedures for defect assessment and disposition have been identified, including inspection and examination practices. The approaches used in Canada and in Belgium, France, Japan, Spain, Sweden, and the USA for fitness-for-service guidelines were compared and contrasted for a variety of defect mechanisms. The strengths and weaknesses of the various approaches have been assessed. The report presents recommendations on approaches that may be adopted in the development of fitness-for-service guidelines for use in the dispositioning of steam generator tubing defects in Canada. (author). 175 refs., 2 tabs., 28 figs

  2. Analysis of forming limit in tube hydroforming

    International Nuclear Information System (INIS)

    Kim, Chan Il; Yang, Seung Hang; Kim, Young Suk

    2013-01-01

    The automotive industry has shown increasing interest in tube hydroforming. Despite many automobile structural parts being produced from cylindrical tubes, failures frequently occur during tube hydroforming under improper forming conditions. These problems include wrinkling, buckling, folding back, and bursting. We perform analytical studies to determine forming limits in tube hydroforming and demonstrate how these forming limits are influenced by the loading path. Theoretical results for the forming limits of wrinkling and bursting are compared with experimental results for an aluminum tube.

  3. MHD Sausage Waves in Compressible Magnetically Twisted Flux Tubes

    Science.gov (United States)

    Fedun, Viktor

    Recent high-resolution satellites clearly prove the existence of various types of theoretically predicted MHD waves in solar atmospheric magnetic structures (loops, arcades ets). Oscillations of magnetic flux tubes are of great importance as they contain information about the geometry and fine structure of the flux tubes. In this work we study the details of the effects caused by the presence of magnetic twist in flux tubes. The propagation of surface and body linear MHD modes in a twisted magnetic flux tube embedded in a magnetically twisted plasma environment is considered. We derive and analytically solve the linear governing equations of wave propagation for sausage surface and body modes of a magnetically-twisted compressible flux tube embedded in a compressible uniformly-magnetized plasma environment in cylindrical geometry in terms of Kummer's functions. Numerical solutions for the phase velocity are obtained for a wide range of wavenumbers and for varying magnetic twist. The effect of magnetic twist on the period of oscillations of sausage surface modes for different values of the wavenumber and vertical magnetic field strength is calculated for representative photospheric and coronal conditions. These results generalize and extend previous studies of MHD waves obtained for incompressible or compressible but non-twisted flux tubes. It is found that magnetic twist may change the period of sausage surface waves by the order of a few per cent when compared to counterparts in straight non-twisted flux tubes. This information will be most relevant, when high-resolution observations are used for diagnostic exploration of MHD wave guides in analogy to solar-interior studies by means of global eigenoscillations in helioseismology. Further detailed analysis is necessary in order to find the dispersion relation for more realistic cases, where the magnetic twist diminishes with distance from the tube. Finally, observational relevances will be discussed in light of the

  4. 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...

  5. The C-terminal hypervariable domain targets Aradopsis ROP9 to the invaginated pollen tube plasma membrane

    Science.gov (United States)

    Rop9 is a small GTPase of the Type II class, whereas the often studied type I Rops play roles during pollen tube growth. In pollen, Rop9 is located at the invaginated plasma membrane that surrounds the sperm cells, whereas type I Rops are located at the apical membrane of the pollen tube. The C-ter...

  6. Study on Acoustic Catheter of Boiler Tube Leakage Monitoring Systems

    Science.gov (United States)

    Lv, Yongxing; Feng, Qiang

    Boiler tube leakage is the major reason of affecting the safe operation of the unit now, there are 3 methods of the "four tube" leakage detection: Traditional method, filtering method and acoustic spectrum analysis, acoustic spectrum analysis is the common method, but this method have low sensitivity and the sensor damage easily. Therewith, designed the special acoustic catheter with acoustic resonance cavity type, proved by experiments, the acoustic catheter with acoustic resonance cavity type can enhance leakage sound, can accurately extract leakage signals, has high sensitivity, and can avoid the effect of sensor by fire and hot-gas when the furnace is in positive pressure situation, reduce the installation and maintenance costs of the boiler tube leakage monitor system.

  7. Optimal tilt-angles of all-glass evacuated tube solar collectors

    International Nuclear Information System (INIS)

    Tang, Runsheng; Gao, Wenfeng; Yu, Yamei; Chen, Hua

    2009-01-01

    In this paper, a detailed mathematical procedure is developed to estimate daily collectible radiation on single tube of all-glass evacuated tube solar collectors based on solar geometry, knowledge of two-dimensional radiation transfer. Results shows that the annual collectible radiation on a tube is affected by many factors such as collector type, central distance between tubes, size of solar tubes, tilt and azimuth angles, use of diffuse flat reflector (DFR, in short); For collectors with identical parameters, T-type collectors (collectors with solar tubes tilt-arranged) annually collect slightly more radiation than H-type collectors (those with solar tubes horizontally arranged) do. The use of DFR can significantly improve the energy collection of collectors. Unlike the flat-plate collectors, all-glass evacuated tube solar collectors should be generally mounted with a tilt-angle less than the site latitude in order to maximize the annual energy collection. For most areas with the site latitude larger than 30 o in China, T-type collectors should be installed with a tilt-angle about 10 o less than the site latitude, whereas for H-type collectors without DFR, the reasonable tilt-angle should be about 20 o less than the site latitude. Effects of some parameters on the annual collectible radiation on the collectors are also presented.

  8. The pulsed-gas tube, statement and perspectives; Le tube a gaz pulse, bilan et perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Domblides, J.P.; Neveau, P.; Castaing-Lasvignottes, J. [Laboratoire du froid du CNAM, 75 - Paris (France)

    1997-12-31

    The pulsed-gas tube has several advantages with respect to the other types of cryo-refrigerating machineries classically used to reach very low temperatures: no mobile parts moving at very low temperatures and no vibrations. However, this system discovered in 1963 is handicapped by its lack of power and by its low energy efficiency. Todays researches about pulsed-gas tubes concern: the technical adaptation of existing systems to applications where its simplicity makes it competitive, the improvement of its energetic performances (refrigerating power and range of temperatures of use), and the development of numerical models in order to better understand the functioning of the system and to optimize it. (J.S.) 19 refs.

  9. On hydraulics of capillary tubes

    Directory of Open Access Journals (Sweden)

    N.G. Aloyan

    2016-03-01

    Full Text Available The article considers the laws of motion of water in the capillary tubes, taken as a model for flowing well, on the analogical net count device. For capillary tube the lower limit value of flow rate is empirically determined above which the total hydraulic resistance of the capillary is practically constant. The specificity of the phenomenon is that the regime of motion, by a Reynolds number, for a given flow rate still remains laminar. This circumstance can perplex the specialists, so the author invites them to the scientific debate on the subject of study. Obviously, to identify the resulting puzzle it is necessary to conduct a series of experiments using capillaries of different lengths and diameters and with different values of overpressure. The article states that in tubes with very small diameter the preliminary magnitude of capillary rise of water in the presence of flow plays no role and can be neglected.

  10. Patient identification and tube labelling

    DEFF Research Database (Denmark)

    van Dongen-Lases, Edmée C; Cornes, Michael P; Grankvist, Kjell

    2016-01-01

    of phlebotomy procedures with the CLSI H3-A6 guideline was unacceptably low, and that patient identification and tube labelling are amongst the most critical steps in need of immediate attention and improvement. The process of patient identification and tube labelling is an essential safety barrier to prevent......Venous blood sampling (phlebotomy) is the most common invasive procedure performed in patient care. Guidelines on the correct practice of phlebotomy are available, including the H3-A6 guideline issued by the Clinical Laboratory Standards Institute (CLSI). As the quality of practices and procedures...... patient identity mix-up. Therefore, the EFLM Working Group aims to encourage and support worldwide harmonisation of patient identification and tube labelling procedures in order to reduce the risk of preanalytical errors and improve patient safety. With this Position paper we wish to raise awareness...

  11. Cathode uniformity of new square photomultiplier tubes

    International Nuclear Information System (INIS)

    Brenner, R.; Chou, H.P.; Strauss, M.G.; Winiecki, A.L.

    1981-01-01

    Square photomultiplier tubes (PMTs) should have better light collection than round PMTs when used in square or rectangular Anger-type #betta#-ray or neutron position detectors. Photocathode response uniformity of new RCA square PMTs type S83003E (51.5 x 51.5 mm 2 ) was measured and compared with conventional round PMTs. The PMTs were scanned with a small scintillation source while the anode signal amplitudes were processed in a computer-based multichannel analyzer. The analyzer was programmed in a mode which virtually eliminates effects due to statistical fluctuations in source rate and output amplitude. Pulse heights as a function of source position on the PMT face are shown for typical tubes. The response uniformity of 64 square PMTs and 21 round ones was evaluated. It is shown that the center region of the square PMTs is as uniform as that of the round ones and that the response in the corners is comparable to that in the center. Thus square PMTs appear to have an advantage for use in square or rectangular position detectors

  12. Studies on heat shrinkage PVC tubes

    International Nuclear Information System (INIS)

    Pyun, Hyung Chick; Kim, Ki Yup; Nho, Young Chang

    1991-01-01

    Radiation crosslinking of PVC was investigated for the purpose of obtaining a suitable formulation for heat shrinkable tube. PVC was not only compounded with various crosslinking agents and plasticizers to evaluate their effects on the radiation sensitivity, heat shrinkable property and other mechanical properties, but also mixed with NBR, crosslinking agents and plasticizers to obtain efficient crosslinking yield and suitable mechanical properties for heat shrinkable tube. Gel yield of PVC increased with increasing unsaturation levels per molecular weight of crosslinking agents. Among crosslinking agents tested, TMPTMA with three unsaturated groups showed highest gel yield, while PVC containing NBR was more sensitive to crosslinking than PVC itself regardless the types of crosslinking agents and plasticizers. Tensile strength was increased with increasing radiation dose and gel percent, but elongation decreased. It was found that gel percent was increased with increasing radiation dose, heat transformation was decreased with increasing gel percent. When NBR was mixed with PVC, the radiation dosage required for enhancing yield of gel percent and heat transformation were found to be much smaller comparing with the case containing no NBR. Therefore, the addition of NBR to PVC was very effective to increase heat-resisting property of PVC. Heat shrinkage was not much varied with radiation dose, the types of crosslinking agents and plasticizers, but it was increased remarkably with decreasing stretching temperature and increasing annealing temperature. (Author)

  13. Nasogastric tube feeding: a safe option for patients?

    Science.gov (United States)

    Williams, Trish

    2016-01-01

    This article will show that fine-bore nasogastric tube feeding can be facilitated for patients when long term percutaneous endoscopic gastrostomy (PEG) or radiologically inserted gastrostomy (RIG) options are not suitable. How the safe replacement of these tubes is facilitated, and what instructions the patient and the nursing home are given to support patient care and safety are also discussed. The decision to support this type of feeding must be completely individualised, considering home and external support agencies available to each patient. The risk assessment completed to facilitate this has been based on the patients' individual circumstances, and a nasogastric tube home passport developed to help in the assessment and decision-making process. For fine-bore nasogastric tube feeding to be safe, it does have to be supported once the patient is discharged from the hospital. A good knowledge of the home support and carer support agencies, and what is available, should be discussed. Multidisciplinary team support is essential in ensuring a safe discharge can be planned and managed. Good patient risk assessment and nursing considerations are discussed to show how the challenges that may prevent a patient discharge with this type of feed are managed. This article will show how two very different patients discharges were facilitated by safe fine-bore nasogastric tube feeding in the community. Patient assessment and nursing considerations are discussed, as well as the importance of a multidisciplinary approach to show how this was successfully achieved in a local district hospital.

  14. Navier–Stokes flow in converging–diverging distensible tubes

    Directory of Open Access Journals (Sweden)

    Taha Sochi

    2015-09-01

    Full Text Available We use a method based on the lubrication approximation in conjunction with a residual-based mass-continuity iterative solution scheme to compute the flow rate and pressure field in distensible converging–diverging tubes for Navier–Stokes fluids. We employ an analytical formula derived from a one-dimensional version of the Navier–Stokes equations to describe the underlying flow model that provides the residual function. This formula correlates the flow rate to the boundary pressures in straight cylindrical elastic tubes with constant-radius. We validate our findings by the convergence toward a final solution with fine discretization as well as by comparison to the Poiseuille-type flow in its convergence toward analytic solutions found earlier in rigid converging–diverging tubes. We also tested the method on limiting special cases of cylindrical elastic tubes with constant-radius where the numerical solutions converged to the expected analytical solutions. The distensible model has also been endorsed by its convergence toward the rigid Poiseuille-type model with increasing the tube wall stiffness. Lubrication-based one-dimensional finite element method was also used for verification. In this investigation five converging–diverging geometries are used for demonstration, validation and as prototypes for modeling converging–diverging geometries in general.

  15. Miniature X-Ray Tubes

    Science.gov (United States)

    Bearman, Gregory H.

    1995-01-01

    Miniature x-ray tubes proposed for use in portable instruments used to analyze minerals. Electrons from field emitter (instead of thermionic emitter) accelerated to target to generate x-rays. Fabricated from silicon wafers, micromachined field emitters (MFEs) not subject to breakage or restrictions on lifetimes, and tolerate vacuums that filaments cannot. Miniature x-ray tubes very robust, immune to shock and vibration, and permanently sealed with getter for continued pumping. Combined with solid-state x-ray detectors for analysis of x-ray fluorescence.

  16. Working session 3: Tubing integrity

    International Nuclear Information System (INIS)

    Cueto-Felgueroso, C.; Strosnider, J.

    1997-01-01

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

  17. Opposed slant tube diabatic sorber

    Science.gov (United States)

    Erickson, Donald C.

    2004-01-20

    A sorber comprised of at least three concentric coils of tubing contained in a shell with a flow path for liquid sorbent in one direction, a flow path for heat transfer fluid which is in counter-current heat exchange relationship with sorbent flow, a sorbate vapor port in communication with at least one of sorbent inlet or exit ports, wherein each coil is coiled in opposite direction to those coils adjoining it, whereby the opposed slant tube configuration is achieved, with structure for flow modification in the core space inside the innermost coil.

  18. YouTube and Facebook

    DEFF Research Database (Denmark)

    Robertson, Scott P.; Vatrapu, Ravi; Medina, Richard

    This paper examines the links to YouTube from the Facebook “walls” of Barack Obama, Hillary Clinton, and John McCain over two years prior to the 2008 U.S. Presidential election. User-generated linkage patterns show how participants in these politically-related social networking dialogues used...... online video to make their points. We show a strong integration of the Web 2.0 and new media technologies of social networking and online video. We argue that political discussion in social networking environments can no longer be viewed as primarily textual, and that neither Facebook nor YouTube can...

  19. 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...... 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...

  20. Deconstructing Pediatric Blenderized Tube Feeding: Getting Started and Problem Solving Common Concerns.

    Science.gov (United States)

    Zettle, Stacey

    2016-12-01

    Blenderized tube feeding has been steadily gaining in popularity among parents and caregivers of tube-fed children. Numerous websites and social media accounts are devoted to the topic, and the parent may be the one to initially broach the subject of implementing this type of feeding plan. This article discusses several different approaches to planning a blenderized tube feeding. As practitioners build their knowledge of and familiarity with blenderized tube feeding, they may feel more comfortable recommending this method to a wider variety of patients.

  1. Application of radioisotope methods of investigation and control techniques in tube production

    International Nuclear Information System (INIS)

    Chizh, V.A.; Drabkin, L.A.

    1975-01-01

    Various spheres of radioactive isotopes application of closed and open type in tube production are described. Due to the usage of radioactive indicator method in combination with physicochemical methods and metallography new data are obtained in the theory and practice of tube centrifugal casting, rolling and pressing. Adsorption properties of lubricants and element distribution in the joint weld region of the big diameter tubes are investigated. The application of radioactive isotopes as ionizing radiation source made it possible to develop some radioisotope methods and instruments for tube wall thickness and the wall thickness difference control. Short characteristics of such instruments are given

  2. Numerical research of the swirling supersonic gas flows in the self-vacuuming vortex tube

    Science.gov (United States)

    Volov, V. T.; Lyaskin, A. S.

    2018-03-01

    This article presents the results of simulation for a special type of vortex tubes – self-vacuuming vortex tube (SVVT), for which extreme values of temperature separation and vacuum are realized. The main results of this study are the flow structure in the SVVT and energy loss estimations on oblique shock waves, gas friction, instant expansion and organization of vortex bundles in SVVT.

  3. Sieve tube geometry in relation to phloem flow

    NARCIS (Netherlands)

    Mullendore, D.L.; Windt, C.W.; As, van H.; Knoblauch, M.

    2010-01-01

    Sieve elements are one of the least understood cell types in plants. Translocation velocities and volume flow to supply sinks with photoassimilates greatly depend on the geometry of the microfluidic sieve tube system and especially on the anatomy of sieve plates and sieve plate pores. Several models

  4. Stability of fluid flow through deformable tubes and channels: An ...

    Indian Academy of Sciences (India)

    S¯adhan¯a Vol. 40, Part 3, May 2015, pp. 925–943. c Indian Academy of Sciences. Stability of fluid flow through deformable tubes and channels: An overview ... tic solid models. All these studies predict several types of instabilities in flow past deformable surfaces. This paper will attempt to place the various theoretical ...

  5. Theory and design of heat exchanger : shell and tube condenser and reboiler

    International Nuclear Information System (INIS)

    Min, Ui Dong

    1996-02-01

    This book gives descriptions of shell and tube heat exchanger including from, sorts, structure like shell and shell side, channel, and sliding bar, basic design of heat exchanger, flow-induced vibration, shell side condenser, tube side condenser and design of basic structure of condenser by types, selection of reboiler type, kettle type reboiler, internal reboiler, pump through reboiler, design of reboiler like kettle and internal reboiler, and horizontal and vertical thermosyphon reboiler.

  6. Social media addiction: What is the role of content in YouTube?

    Science.gov (United States)

    Balakrishnan, Janarthanan; Griffiths, Mark D

    2017-09-01

    Background YouTube, the online video creation and sharing site, supports both video content viewing and content creation activities. For a minority of people, the time spent engaging with YouTube can be excessive and potentially problematic. Method This study analyzed the relationship between content viewing, content creation, and YouTube addiction in a survey of 410 Indian-student YouTube users. It also examined the influence of content, social, technology, and process gratifications on user inclination toward YouTube content viewing and content creation. Results The results demonstrated that content creation in YouTube had a closer relationship with YouTube addiction than content viewing. Furthermore, social gratification was found to have a significant influence on both types of YouTube activities, whereas technology gratification did not significantly influence them. Among all perceived gratifications, content gratification had the highest relationship coefficient value with YouTube content creation inclination. The model fit and variance extracted by the endogenous constructs were good, which further validated the results of the analysis. Conclusion The study facilitates new ways to explore user gratification in using YouTube and how the channel responds to it.

  7. Detecting Enteral Nutrition Residues and Microorganism Proliferation in Feeding Tubes via Real-Time Imaging.

    Science.gov (United States)

    Yamaoka, Ippei; Kagawa, Tomohiro; Mizugai, Kazuya; Ebisu, Goro

    2017-04-01

    Enteral nutrition (EN) residues that persist in feeding tubes provide substrates for microorganisms to proliferate and occlude the tubes. Visible EN residues in tubes are easily identified, but smaller residues can persist. We developed a new imaging technique to visualize EN residues and proliferation of microorganisms in feeding tubes. (1) Feeding tubes containing EN labeled with fluorescent dye and either with or without various types or amounts of thickeners were flushed once with water and then seeded with Pseudomonas aeruginosa Xen05 with recombinant luciferase DNA. (2) Because EN fluoresces intrinsically, EN in the feeding tubes without fluorescent dye was repeatedly flushed until the intrinsic fluorescence levels reached background levels. Fluorescent images of EN residues and bioluminescent images of microorganisms were acquired via an optical imaging system. (1) Fluorescence images showed that the amount of EN residues increased at various sites in tubes depending on EN viscosity and the thickening agent, and bioluminescence images showed that microorganism proliferation was associated with a commensurate increase in EN residues. (2) The intrinsic fluorescence of EN also enabled the detection of EN residues in tubes even in the absence of fluorescence dye. Higher EN viscosity required more flushes to reach undetectable levels. EN residues and microorganism proliferation in enteral feeding tubes were detected on fluorescence and bioluminescence images, respectively. This simplified approach allowed the real-time visualization of EN residues and microorganisms in feeding tubes.

  8. Study on antioxidant experiment on forged steel tube sheet and tube hole for steam generator

    International Nuclear Information System (INIS)

    Zong Hai; Wang Detai; Ding Yang

    2012-01-01

    Antioxidant experiment on forged steel tube sheet and tube hole for steam generator was studied and the influence of different simulated heat treatments on the antioxidant performance of tube sheet and tube hole was made. The influence of different antioxidant methods on the size of tube hole was drawn. Furthermore, the change of size and weight of 18MnD5 forged steel tube sheet on the condition of different simulated heat treatments was also studied. The analytical results have proved reference information for the use of 18MnD5 material and for key processes of processing tube hole and wearing and expanding U-style tube. (authors)

  9. Self-sensing concrete-filled FRP tubes using FBG strain sensors

    Science.gov (United States)

    Yan, Xin; Li, Hui

    2007-07-01

    Concrete-filled fiber-reinforced polymer (FRP) tube is a type of newly developed structural column. It behaves brittle failure at its peak strength, and so the health monitoring on the hoop strain of the FRP tube is essential for the life cycle safety of the structure. Herein, three types of FRP tubes including 5-ply tube, 2-ply tube with local reinforcement and FRP-steel composite tube were embedded with the optic fiber Bragg grating (FBG) strain sensors in the inter-ply of FRP or the interface between FRP and steel in the middle height and the hoop direction. The compressive behaviors of the concrete-filled FRP tubes were experimentally studied. The hoop strains of the FRP tubes were recorded in real time using the embedded FBG strain sensors as well as the embedded or surface electric resistance strain gauges. Results indicated that the FBG strain sensors can faithfully record the hoop strains of the FRP tubes in compression as compared with the embedded or surface electric resistance strain gauges, and the strains recorded can reach more than μɛ.

  10. Mechanical support for straw tubes

    International Nuclear Information System (INIS)

    Joestlein, H.

    1990-01-01

    A design is proposed for mounting a large number of straw tubes to form an SSC central tracking chamber. The assembly is precise and of very low mass. The fabrication is modular and can be carried out with a minimum of tooling and instrumentation. Testing of modules is possible prior to the final assembly. 4 figs

  11. 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

  12. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... Program Vision and Aging Program African American Program Training and Jobs Fellowships NEI Summer Intern Program Diversity In Vision Research & Ophthalmology (DIVRO) Student Training Programs To search for current job openings visit HHS USAJobs Home >> NEI YouTube Videos >> ...

  13. Case of nasogastric tube dysfunction.

    Science.gov (United States)

    Rainer, Florian; Prenner, Guenther; Binder, Lukas Peter; Fickert, Peter; Plank, Johannes

    2018-01-05

    An elderly female patient was admitted to intensive care for prolonged vasopressor therapy and mechanical ventilation after cardiac arrest and acute percutaneous coronary intervention. Antiplatelet, thyroid hormone replacement and statin therapies were administered through a 14-French nasogastric tube (Nestlé Health Science) and enteral feeding was initiated. Correct position of the nasogastric tube was confirmed radiologically. On the seventh day in the intensive care, our patient was seen to regurgitate soft crumbs into her mouth. The blocked nasogastric tube was removed, but attempts to reinsert another tube failed.Upper GI endoscopy revealed an obstruction of the oesophagus with a milky-yellowish caseous substance 20 cm from the incisors (figure 1). The proximal part of the mass showed a central hole and ring-shaped layers resembling the cut face of a tree trunk.gutjnl;gutjnl-2017-315619v1/F1F1F1Figure 1Obstruction of the oesophagus with a milky-yellowish caseous substance. What caused the obstruction?How should we manage such a problem? © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  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. Steam generator tube integrity program

    International Nuclear Information System (INIS)

    Diercks, D.R.; Shack, W.J.

    1996-01-01

    The degradation of steam generator tubes in pressurized water nuclear reactors continues to be a serious problem, and the US Nuclear Regulatory Commission (NRC) is developing a performance-based rule and regulatory guide for steam generator tube integrity. To support the evaluation of industry-proposed implementation of these performance-based criteria, the NRC is sponsoring a new research program at Argonne National Laboratory on steam generator tubing degradation. The objective of the new program is to provide the necessary experimental data and predictive correlations and models that will permit the NRC to independently evaluate the integrity of steam generator tubes. The technical work in the program is divided into four tasks, (1) assessment of inspection reliability, (2) research on in-service inspection technology, (3) research on degradation modes and integrity, and (4) development of methodology and technical assessments for current and emerging regulatory issues. The objectives of and planned research activities under each of these four tasks are described here. (orig.)

  16. Tube in shell heat exchangers

    International Nuclear Information System (INIS)

    Hayden, O.; Willby, C.R.; Sheward, G.E.; Ormrod, D.T.; Firth, G.F.

    1980-01-01

    An improved tube-in-shell heat exchanger to be used between liquid metal and water is described for use in the liquid metal coolant system of fast breeder reactors. It is stated that this design is less prone to failures which could result in sodium water reactions than previous exchangers. (UK)

  17. Tubing with high corrosion resistance

    Science.gov (United States)

    Ioffe, A. V.; Tetyueva, T. V.; Vyboyshchik, M. A.; Trifonova, E. A.; Lutsenko, E. S.

    2010-07-01

    The optimum chemical composition and the regime for heat treatment of heat-resistant steel 15Kh5M are determined for the production of tubing with strength of group L80 (API 5CT) and high cold resistance and resistance to carbon dioxide and sulfurated hydrogen corrosion at low alloying additives of chromium and molybdenum.

  18. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... Macular Degeneration Amblyopia Animations Blindness Cataract Convergence Insufficiency Diabetic Eye Disease Dilated Eye Exam Dry Eye For Kids Glaucoma Healthy Vision Tips Leber Congenital Amaurosis Low Vision Refractive Errors Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube ...

  19. 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.

  20. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... and Aging Program African American Program Training and Jobs Fellowships NEI Summer Intern Program Diversity In Vision ... DIVRO) Student Training Programs To search for current job openings visit HHS USAJobs Home » NEI YouTube Videos » ...

  1. 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 part...

  2. On Poor Separation in Magnetically Driven Shock Tube

    DEFF Research Database (Denmark)

    Chang, C.T.

    1973-01-01

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

  3. Pressure effect on the sensitivity of quartz Bourdon tube gauges.

    Science.gov (United States)

    Szaniszlo, A. J.

    1972-01-01

    The sensitivity change for a commercial fused quartz Bourdon tube precision pressure gauge, due to a change in absolute pressure level, has been analytically computed and experimentally confirmed. The computed differential pressure error is 2.5% of full scale at a 100 atm absolute pressure level. The experimental method compared the fused quartz Bourdon tube gauge digital output to the results obtained from a nitrogen gas pressure system which had a high pressure, well-type mercury manometer as the differential pressure reference.

  4. Investigations into the dynamic behaviour of finned tube heat exchangers

    International Nuclear Information System (INIS)

    Sandbrink, J.; Stegemann, D.

    1981-01-01

    Atmospheric disturbances due to thunder storms, side wind effects on the shell or ground inversion can impair the heat dissipation of a cooling tower. These effects react on the overall power plant, which is reflected in the varied electrical output. This uncontrolled behaviour has been investigated in detail for the case of a boiling water reactor nuclear power station with indirect natural draught dry cooling and compared with controlled performance. A computer model, which has been checked out by means of experimental investigations on three different types of tube, is presented to describe the dynamic behaviour of finned tube heat exchangers. (orig.) [de

  5. Shell-and-double concentric-tube heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Bougriou, Cherif; Baadache, Khireddine [University of Batna, Department of Mechanics, Batna (Algeria)

    2010-03-15

    This study concerns a new type of heat exchangers, which is that of shell-and-double concentric-tube heat exchangers. These heat exchangers can be used in many specific applications such as air conditioning, waste heat recovery, chemical processing, pharmaceutical industries, power production, transport, distillation, food processing, cryogenics, etc. The case studies include both design calculations and performance calculations. It is demonstrated that the relative diameter sizes of the two tubes with respect to each other are the most important parameters that influence the heat exchanger size. (orig.)

  6. Schizophrenia on YouTube.

    Science.gov (United States)

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

    2017-01-01

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

  7. Preparation of metallic uranium tubes

    International Nuclear Information System (INIS)

    Lerouge, G.; Decours, J.

    1964-01-01

    The production furnace is an induction heated vacuum furnace having a capacity at the moment of 250 kg. Previously the crucible was heated by the inductor, the mould being outside the inductor. The tubes thus produced contained cavities, the alloy structure was fine; this was cold-mould casting, At the moment the top of the moulds are pre-heated, this is the so called hot-mould casting. This method has the advantage of eliminating the cavities but leads to a less fine microstructure. The alloy used for the 18 x 40 mm and 23 x 43 mm tubes is U-Mo (1.1 per cent). Since the moulds are now heated at the top, the solidification of the metal is very slow in this zone leading to a pronounced γ grain, whereas towards the base the faster cooling leads to a smaller γ grain. The γ structure depends essentially on the solidification rate and on the time spent in this zone. In order to obtain a fine and homogeneous grain along the whole length of the tube, a controlled cooling treatment is effected. It consists in heating the uranium tubes in the γ place and then in cooling them at a rate of between 20 and 50 deg C/mm down to 400 deg C. The 77 x 95 mm and 54 x 70 mm annular elements are at the moment being produced for research purposes. Their preparation is similar to that of 18 x 40 mm and 23 x 43 mm elements. The 77 x 95 mm tubes are at the moment made from U-Cr alloy (0.1 per cent); because of their size, their preparation is carried out in 600 mm diameter furnaces. (authors) [fr

  8. Improving the calandria tubes for CANDU reactors

    International Nuclear Information System (INIS)

    Coleman, C.E.; Fong, R.W.L.; Doubt, G.L.

    1997-01-01

    CANDU calandria tubes are made from annealed Zircaloy-2 sheet formed into a cylinder and welded along its length to make the tube. The current calandria tubes have given exemplary service for many years. With more stringent regulations and the need to accommodate warm cooling water in tropical countries, we started a development program to increase the margins for failure during postulated accidents. These improvements involve increasing the tube strength and optimising the heat-transfer from an excessively hot fuel channel to the cool moderator. If the postulated accident involves a pressure tube break, it would be desirable if the calandria tube withstood the full pressure of the heat-transport system. The weakest link in current calandria tubes is the weld. Thickening the weld can increase the strength by 20% while seamless tubes can be 45% stronger than current tubes. The latter tubes can hold full system pressure for many hours without failure. If during the postulated accident the fuel and pressure tube become excessively hot but do not touch the calandria tube, the radiant heat loss must be maximised. Current calandria tubes have an absorptivity (emissivity) of about 0.2. To protect the fuel and the fuel channel we have devised a finish to the inside surface of the calandria tube that increases the emissivity to 0.7. If during the postulated accident the hot pressure tube touches the cool calandria tube, the contact conductance and the critical heat flux must be optimised to ensure nucleate boiling of the moderator at the outside surface of the calandria tube and therefore efficient exploitation of the moderator as a heat sink. In laboratory tests small ridges on the inside surface and roughening of the outside surface have been shown to increase the margins against failure and increase the possible moderator temperatures thus providing the opportunity to decrease the cost of the moderator heat-exchange system and remove restrictions on reactor operation in

  9. A case of a 'lost' nasogastric tube.

    Science.gov (United States)

    Sankar, V; Shakeel, M; Keh, S; Ah-See, K W

    2012-12-01

    To present the case of a 'lost' nasogastric tube and to highlight the importance of imaging and/or chest X-ray after nasogastric tube insertion, especially in unreliable patients. A 50-year-old man, undergoing radiotherapy treatment for squamous cell carcinoma of the tongue base, was admitted for pain control and nasogastric tube feeding. This patient required multiple nasogastric tubes over a two-week period. The patient repeatedly denied pulling the nasogastric tube out and we were unable to establish the exact mode of nasogastric tube removal. On one such occasion another tube was inserted and a check X-ray showed two feeding tubes; the latest one was lying in the left main bronchus and the old nasogastric tube was observed in the oesophagus, with its upper end jutting above the hypopharynx. It was apparent that the patient had somehow cut the tube and swallowed it. This case not only illustrates the importance of flexible nasendoscopy and/or chest X-ray for checking the position of the nasogastric tube, but also highlights that some patients are not tolerant of nasogastric tubes. The use of nasogastric tubes should be avoided in these patients to prevent any self-inflicted injury.

  10. Review of damages of nuclear power plants steam generator's tubes and way of detecting by using eddy current method

    International Nuclear Information System (INIS)

    Stanic, D.

    1996-01-01

    Steam generator tubing integrity is very important factor for reliable and safe operation of NPP. Several different types of tube degradation mechanisms were experienced in SG operation. To avoid possible tube rupture and primary-to-secondary leak, the EC examination of tubing should be performed. Different eddy current techniques may be used for detecting defects and theirs characterization. A comparison of data analysis results with pulled tube destructive metallography results can provide valuable insights in determining the capability of existing technology and provide guidance for procedure or technology improvements. (author)

  11. [Tracheal intubation with Parker Flex-Tip tubes assisted by tube-guiding devices].

    Science.gov (United States)

    Mizuno, Ju; Morita, Shigeho; Suzuki, Maya; Arita, Hideko; Hanaoka, Kazuo

    2010-04-01

    In tracheal intubation assisted by tube-guiding devices passing through the tube, such as fiberoptic scopes, bougies, tracheal tube exchange catheters, and light wands, passage of the tube-guiding device, by itself, is often easy. But advancing a tracheal tube with a conventional distal tip over these tube-guiding devices is frequently difficult or impossible, because its rigid, side-beveled tip frequently catches on anatomical features of the airway. A novel tracheal tube, the Parker Flex-Tip tube (Parker Medical, Colorado, USA) has a centered, curved, tapered and flexible distal tip that passes through the airway faster and easier than conventional tracheal tubes. As it is advanced along a tube-guiding device, the tip of the Parker tube travels along the midline of the airway, without the gap that usually exists between the distal edge of a conventional tracheal tube and the tube-guiding device. The gapless, midline travel of the Parker tube leads to a greater incidence of first-attempt intubation success with tube-guiding devices, because there is less risk of tube tip hang-ups on the arytenoids and the vocal cords. Clinically, use of the Parker tube is helpful for oral and nasal intubations, especially in patients with difficult airways.

  12. A Study on the Development of Nonglass Solar Vacuum Tube Collector

    International Nuclear Information System (INIS)

    Oh, Seung Jin

    2008-02-01

    Nature has been providing us energy from the beginning of the world. However human has hardly used it wisely. Solar energy is a kind of renewable energy from the nature. This study has been carried out to study the use of solar energy as it is harnessed in the form of thermal energy. Solar energy is one of the most promising energy resources such as hydrogen, biomass, wind and geothermal energy, because it is clean and inexhaustible. Space heating in buildings can be provided from solar energy by systems that are similar in many respects to water heater systems. By tapping into solar energy, we can not only solve the problem of energy shortage, but also can protect the environment and benefit the human beings. There are currently two types of evacuated tube; a single glass tube and a double glass tube. The former consists of a single glass tube which contains a flat or curved aluminium plate attached to a copper heat pipe or water flow pipe. The latter consists of rows of parallel transparent glass tubes, each of which contains an absorber tube. Evacuated tube collectors introduced above, however, pose some problems as they break rather easily under mechanical stresses. This paper introduces some preliminary results in design and fabrication of a non-glass solar vacuum tube collector in which the thermosyphon(heat pipe)made of copper is used as a heat transfer device. A series of tests have been performed to assess the ability of a non-glass solar vacuum tube collector. The series of experiments are as follows: 1)Vacuum level inside a vacuum tube. 2)Effects of the air remaining inside a vacuum tube on the temperature on the absorber plate. 3)Comparison of a non-glass vacuum solar collector with a single glass evacuated tube(SEIDO 5). Different vacuum levels inside non-glass vacuum tubes were applied to check any leakage or unexpected physical or chemical developments with time. The vacuum level changed from 10 -2 torr to 5torr in 5 days due to air infiltration from

  13. Outcomes of Infants with Home Tube Feeding: Comparing Nasogastric Versus Gastrostomy Tubes

    Science.gov (United States)

    Khalil, Syed Tariq; Uhing, Michael R.; Duesing, Lori; Visotcky, Alexis; Tarima, Sergey; Nghiem-Rao, T. Hang

    2017-01-01

    Background Determine the tube-related complications and feeding outcomes of infants discharged home from the NICU with nasogastric (NG) tube feeding or gastrostomy (G-tube) feeding. Material & Methods We performed a chart review of 335 infants discharged from our NICU with home NG tube or G-tube feeding between January 2009 – December 2013. The primary outcome was the incidence of feeding tube-related complications requiring emergency department (ED) visits, hospitalizations, or deaths. Secondary outcome was feeding status at 6 months post-discharge. Univariate and multivariate analyses were conducted. Results There were 322 infants discharged with home enteral tube feeding, 84 NG tube and 238 G-tube, with available out-patient data for the 6 month post-discharge period. A total of 115 ED visits, 28 hospitalizations, and 2 deaths were due to a tube-related complication. The incidence of tube-related complications requiring an ED visit was significantly higher in the G-tube group compared to the NG tube group (33.6% vs 9.5%, p tube related complication. By 6 months post-discharge, full oral feeding was achieved in 71.4% of infants in the NG tube group compared to 19.3% in the G-tube group (p tube and percentage of oral feeding at discharge were significantly associated with continued tube feeding at 6 months post-discharge. Conclusion Home NG tube feeding is associated with fewer ED visits for tube-related complications compared to home G-tube feeding. There may be some infants who could benefit from a trial home NG tube feeding. PMID:27647478

  14. Outcomes of Infants With Home Tube Feeding: Comparing Nasogastric vs Gastrostomy Tubes.

    Science.gov (United States)

    Khalil, Syed Tariq; Uhing, Michael R; Duesing, Lori; Visotcky, Alexis; Tarima, Sergey; Nghiem-Rao, T Hang

    2017-11-01

    The aim of this study was to determine the tube-related complications and feeding outcomes of infants discharged home from the neonatal intensive care unit (NICU) with nasogastric (NG) tube feeding or gastrostomy (G-tube) feeding. We performed a chart review of 335 infants discharged from our NICU with home NG tube or G-tube feeding between January 2009 and December 2013. The primary outcome was the incidence of feeding tube-related complications requiring emergency department (ED) visits, hospitalizations, or deaths. Secondary outcome was feeding status at 6 months postdischarge. Univariate and multivariate analyses were conducted. There were 322 infants discharged with home enteral tube feeding (NG tube, n = 84; G-tube, n = 238), with available outpatient data for the 6-month postdischarge period. A total of 115 ED visits, 28 hospitalizations, and 2 deaths were due to a tube-related complication. The incidence of tube-related complications requiring an ED visit was significantly higher in the G-tube group compared with the NG tube group (33.6% vs 9.5%, P tube-related complication. By 6 months postdischarge, full oral feeding was achieved in 71.4% of infants in the NG tube group compared with 19.3% in the G-tube group ( P tube and percentage of oral feeding at discharge were significantly associated with continued tube feeding at 6 months postdischarge. Home NG tube feeding is associated with fewer ED visits for tube-related complications compared with home G-tube feeding. Some infants could benefit from a trial home NG tube feeding.

  15. In service inspection for steam generator tubes

    International Nuclear Information System (INIS)

    Comby, R.; Eyrolles, Ph.

    1988-01-01

    In this paper the authors show the means putting in place for examination of steam generators tubes. These means (eddy current probes, ultrasonic testing) associated with a knowledge on degradation phenomena allow mapping controlled tubes and limiting undesirable obturations [fr

  16. X-ray tube current control

    International Nuclear Information System (INIS)

    Dupuis, W.A.; Resnick, T.A.

    1982-01-01

    A closed loop feedback system for controlling the current output of an x-ray tube. The system has circuitry for improving the transient response and stability of the x-ray tube current over a substantial nonlinear portion of the tube current production characteristic. The system includes a reference generator for applying adjustable step function reference signals representing desired tube currents. The system also includes means for instantaneous sensing of actual tube current. An error detector compares the value of actual and reference tube current and produces an error signal as a function of their difference. The system feedback loop includes amplification circuitry for controlling x-ray tube filament dc voltage to regulate tube current as a function of the error signal value. The system also includes compensation circuitry, between the reference generator and the amplification circuitry, to vary the loop gain of the feedback control system as a function of the reference magnitude

  17. 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.

  18. Chemical cleaning specification: few tube test model

    International Nuclear Information System (INIS)

    Hampton, L.V.; Simpson, J.L.

    1979-09-01

    The specification is for the waterside chemical cleaning of the 2 1/4 Cr - 1 Mo steel steam generator tubes. It describes the reagents and conditions for post-chemical cleaning passivation of the evaporator tubes

  19. Prestressed Carbon Fiber Composite Overwrapped Gun Tube

    National Research Council Canada - National Science Library

    Littlefield, Andrew; Hyland, Edward

    2006-01-01

    .... Using composite materials not only directly removes weight from the gun tube but, by better balancing the tube, allows the use of smaller drive systems, thus further enhancing the system weight loss...

  20. High grade serous ovarian carcinomas originate in the fallopian tube.

    Science.gov (United States)

    Labidi-Galy, S Intidhar; Papp, Eniko; Hallberg, Dorothy; Niknafs, Noushin; Adleff, Vilmos; Noe, Michael; Bhattacharya, Rohit; Novak, Marian; Jones, Siân; Phallen, Jillian; Hruban, Carolyn A; Hirsch, Michelle S; Lin, Douglas I; Schwartz, Lauren; Maire, Cecile L; Tille, Jean-Christophe; Bowden, Michaela; Ayhan, Ayse; Wood, Laura D; Scharpf, Robert B; Kurman, Robert; Wang, Tian-Li; Shih, Ie-Ming; Karchin, Rachel; Drapkin, Ronny; Velculescu, Victor E

    2017-10-23

    High-grade serous ovarian carcinoma (HGSOC) is the most frequent type of ovarian cancer and has a poor outcome. It has been proposed that fallopian tube cancers may be precursors of HGSOC but evolutionary evidence for this hypothesis has been limited. Here, we perform whole-exome sequence and copy number analyses of laser capture microdissected fallopian tube lesions (p53 signatures, serous tubal intraepithelial carcinomas (STICs), and fallopian tube carcinomas), ovarian cancers, and metastases from nine patients. The majority of tumor-specific alterations in ovarian cancers were present in STICs, including those affecting TP53, BRCA1, BRCA2 or PTEN. Evolutionary analyses reveal that p53 signatures and STICs are precursors of ovarian carcinoma and identify a window of 7 years between development of a STIC and initiation of ovarian carcinoma, with metastases following rapidly thereafter. Our results provide insights into the etiology of ovarian cancer and have implications for prevention, early detection and therapeutic intervention of this disease.

  1. Production and testing of tubes for nuclear boiler steam generators

    International Nuclear Information System (INIS)

    Jacson, M.

    1977-01-01

    Vallourec, second pipe manufacturer in Europe, has developed a workshop for the production of nuclear heat exchanger tubes in its Montbard plant. This workshop, by its special construction, production engineering and handling procedures, has attained nuclear standards and can produce U-bended tubes from diameter 12 to 25 mm with a maximum length of 36 meters. Its annual out-put is 1.500.000 meters. The final dimensions are obtained by a cold rolling procedure, followed by an outside and inside degreasing, a solution annealing in a controlled atmosphere continuous type furnace, a surface grinding and an inside surface conditionning. The non-destructive tests: eddy currents, ultrasonic tests and thickness mesures are recorded on a single tube basis. The curving and packing procedures have been specially developed for this production [fr

  2. Endurance of Damping Properties of Foam-Filled Tubes

    Directory of Open Access Journals (Sweden)

    Matteo Strano

    2015-07-01

    Full Text Available The favorable energy-absorption properties of metal foams have been frequently proposed for damping or anti-crash applications. The aim of this paper is to investigate the endurance of these properties for composite structures, made by a metal or a hybrid metal-polymeric foam used as the core filling of a tubular metal case. The results of experimental tests are shown, run with two types of structures: 1 square steel tubes filled with aluminum or with hybrid aluminum-polymer foams; 2 round titanium tubes filled with aluminum foams. The paper shows that the damping properties of a foam-filled tube change (improve with the number of cycles, while all other dynamic properties are nearly constant. This result is very important for several potential applications where damping is crucial, e.g., for machine tools.

  3. Endurance of Damping Properties of Foam-Filled Tubes.

    Science.gov (United States)

    Strano, Matteo; Marra, Alessandro; Mussi, Valerio; Goletti, Massimo; Bocher, Philippe

    2015-07-07

    The favorable energy-absorption properties of metal foams have been frequently proposed for damping or anti-crash applications. The aim of this paper is to investigate the endurance of these properties for composite structures, made by a metal or a hybrid metal-polymeric foam used as the core filling of a tubular metal case. The results of experimental tests are shown, run with two types of structures: 1) square steel tubes filled with aluminum or with hybrid aluminum-polymer foams; 2) round titanium tubes filled with aluminum foams. The paper shows that the damping properties of a foam-filled tube change (improve) with the number of cycles, while all other dynamic properties are nearly constant. This result is very important for several potential applications where damping is crucial, e.g., for machine tools.

  4. Burst pressure and leak rate from fretted SG tubes

    International Nuclear Information System (INIS)

    Hwang, Seong Sik; Jung, Man Kyo; Kim, Hong Pyo; Kim, Joung Soo

    2005-01-01

    Steam generator(SG) tubes of a pressurized water reactor(PWR) have suffered from various types of corrosion, such as pitting, wastage and stress corrosion cracking (SCC) on both the primary and secondary side. Recently, fretting/wear degradation at the tube support region has been reported in some Korean nuclear power plants. In order to prevent the primary coolant from leaking to the secondary side, the tubes are repaired by a sleeving or plugging. It is important to establish the repair criteria to assure a reactor integrity and yet maintain the plugging ratio within the limits needed for an efficient operation. The objective of the burst test is to obtain a relationship between the burst/leak rate and the shape of the fretted flaws machined with an electro discharge machining (EDM)

  5. Repair technology for steam generator tubes

    International Nuclear Information System (INIS)

    Kim, Seung Ho; Jung, Hyun Kyu; Jung, Seung Ho; Kim, Chang Hoi; Jung, Young Moo; Seo, Yong Chil; Kim, Jung Su; Seo, Moo Hong

    2001-02-01

    The most commonly used sleeving materials are thermally treated Alloy 600 and thermally treated Alloy 690 Alloy. Currently, thermally treated Alloy 690 and Alloy 800 are being offered although Alloy 800 has not been licensed in the US. To install sleeve, joint strength, leak tightness, PWSCC resistance, evaluation on process parameter range and the effect of equipments and procedures on repair plan and radiation damage have to be investigated before sleeving. ABB CE provides three type of leak tight Alloy 690 TIG welded and PLUSS sleeve. Currently, Direct Tube Repair technique using Nd:YAG laser has been developed by ABB CE and Westinghouse. FTI has brazed and kinetic sleeve designs for recirculating steam generator and hydraulic and rolled sleeve designs for one-through steam generators. Westinghouse provides HEJ, brazed and laser welded sleeve design. When sleeve is installed in order to repair the damaged S/G tubes, it is certain that defects can be occurred due to the plastic induced stress and thermal stress. Therefore it is important to minimize the residual stress. FTI provides the electrosleeve technique as a future repair candidate using electroplating

  6. Repair technology for steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung Ho; Jung, Hyun Kyu; Jung, Seung Ho; Kim, Chang Hoi; Jung, Young Moo; Seo, Yong Chil; Kim, Jung Su; Seo, Moo Hong

    2001-02-01

    The most commonly used sleeving materials are thermally treated Alloy 600 and thermally treated Alloy 690 Alloy. Currently, thermally treated Alloy 690 and Alloy 800 are being offered although Alloy 800 has not been licensed in the US. To install sleeve, joint strength, leak tightness, PWSCC resistance, evaluation on process parameter range and the effect of equipments and procedures on repair plan and radiation damage have to be investigated before sleeving. ABB CE provides three type of leak tight Alloy 690 TIG welded and PLUSS sleeve. Currently, Direct Tube Repair technique using Nd:YAG laser has been developed by ABB CE and Westinghouse. FTI has brazed and kinetic sleeve designs for recirculating steam generator and hydraulic and rolled sleeve designs for one-through steam generators. Westinghouse provides HEJ, brazed and laser welded sleeve design. When sleeve is installed in order to repair the damaged S/G tubes, it is certain that defects can be occurred due to the plastic induced stress and thermal stress. Therefore it is important to minimize the residual stress. FTI provides the electrosleeve technique as a future repair candidate using electroplating.

  7. Neutron generator tube ion source control apparatus

    International Nuclear Information System (INIS)

    Bridges, J.R.

    1982-01-01

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

  8. Detection of steam generator tube leaks in pressurized water reactors

    International Nuclear Information System (INIS)

    Roach, W.H.

    1985-01-01

    This report addresses the early detection of small steam generator tube leaks in pressurized water reactors. It discusses the third, and final, year's work on an NRC-funded project examining diagnostic instrumentation in water reactors. The first two years were broad in coverage, concentrating on anticipatory measurements for detection of potential problems in both pressurized- and boiling-water reactors, with recommendations for areas of further study. One of these areas, the early detection of small steam tube leaks in PWRs, formed the basis of study for the last year of the project. Four tasks are addressed in this study of the detection of steam tube leaks. (1) Determination of which physical parameters indicate the onset of steam generator tube leaks. (2) Establishing performance goals for diagnostic instruments which could be used for early detection of steam generator tube leaks. (3) Defining the diagnostic instrumentation and their location which satisfy Items 1 and 2 above. (4) Assessing the need for diagnostic data processing and display. Parameters are identified, performance goals established, and sensor types and locations are specified in the report, with emphasis on the use of existing instrumentation with a minimum of retrofitting. A simple algorithm is developed which yields the leak rate as a function of known or measurable quantities. The conclusion is that leak rates of less than one-tenth gram per second should be detectable with existing instrumentation. (orig./HP)

  9. Replaceable Jejunal Feeding Tubes in Severely Ill Children

    Directory of Open Access Journals (Sweden)

    Tabea Pang

    2017-01-01

    Full Text Available Long-term enteral nutrition in chronically ill, malnourished children represents a clinical challenge if adequate feeding via nasogastric or gastrostomy tubes fails. We evaluated the usefulness and complications of a new type of surgical jejunostomy that allows for easier positioning and replacement of the jejunal feeding tube in children. We surgically inserted replaceable jejunal feeding tubes (RJFT connected to a guide thread which exited through a separate tiny opening of the abdominal wall. In a retrospective case series, we assessed the effectiveness and complications of this technique in severely ill children suffering from malnutrition and complex disorders. Three surgical complications occurred, and these were addressed by reoperation. Four children died from their severe chronic disorders within the study period. The RJFT permitted continuous enteral feeding and facilitated easy replacement of the tube. After the postoperative period, jejunal feeding by RJFT resulted in adequate weight gain. This feeding access represents an option for children in whom sufficient enteral nutrition by nasogastric tubes or gastrostomy proved impossible. Further studies are required to investigate the safety and effectiveness of this surgical technique in a larger case series.

  10. Tube and column agglutination technology for autocontrol testing.

    Science.gov (United States)

    Courtney, J E; Vincent, J L; Indrikovs, A J

    2001-01-01

    The incidence of positive autocontrol test results with column agglutination technology is a concern. This study investigates the incidence and significance of positive autocontrols in the ID Micro Typing System (gel) and the Gamma ReACT (ReACT). The study encompassed a total of 1021 randomly selected samples from patients and 95 samples from donors collected during 1 month. The autocontrol testing was carried out according to the manufacturer's instructions for the column agglutination tests. The tube method was carried out using low-ionic-strength solution (LISS). The direct antiglobulin test (DAT) was performed using the tube method, and further investigated with elution studies if warranted. Seventy-nine patient's samples (7.74%) had a positive autocontrol: the gel test, 72 (91.13%); ReACT, 21 (26.58%); and the tube method, 27 (34.18%). Of the 79 positive autocontrols, 44 samples had a negative DAT. Of the samples with positive DAT results, only one possessed a clinically significant antibody, anti-D. Moreover, the same sample also tested positive in all three methods. Column agglutination techniques have increased sensitivity for a positive autocontrol beyond the conventional tube method. However, ReACT and gel tests differ significantly in their frequency of positives. Investigation of the significance of a positive autocontrol in column agglutination technology when the conventional tube method is also positive is suggested.

  11. Recurrent white thrombi formation in hemodialysis tubing: a case report.

    Science.gov (United States)

    Sathe, Kiran P; Yeo, Wee-Song; Liu, Isaac Desheng; Ekambaram, Sudha; Azar, Mohammed; Yap, Hui-Kim; Ng, Kar-Hui

    2015-01-15

    While the appearance of red clots in the dialyzer is a common phenomenon in every hemodialysis unit, the occurrence of white thrombi in the tubing is relatively rare. We describe an adolescent male with recurrent white thrombi formation in the hemodialysis tubing. This patient had chronic renal failure from focal segmental glomerulosclerosis, but was no longer nephrotic at the time of the thrombi formation. He had a history of recurrent thrombosis of his vascular access. However, no pro-thrombotic risk factors could be identified. White particulate matter, measuring 1 to 3mm in size, and adherent to the arterial and venous blood tubing lines was found during the rinse back of a hemodialysis session. This was associated with a 60% decrease in his platelet count. Light microscopic examination of the deposits revealed the presence of platelet aggregates. He subsequently developed thrombosis of his arteriovenous graft six hours later. The white thrombi recurred at the next dialysis session, as well as six months later. These episodes occurred regardless of the type of dialysis machine or tubing, and appeared to resolve with an increase in heparin dose. Recurrent white thrombi formation can occur in the hemodialysis tubing of a patient with no identifiable pro-thrombotic factors. The white thrombi may be a harbinger of arteriovenous graft thrombosis and may be prevented by an increase in heparin dose.

  12. Preservative loss from silicone tubing during filling processes.

    Science.gov (United States)

    Saller, Verena; Matilainen, Julia; Rothkopf, Christian; Serafin, Daniel; Bechtold-Peters, Karoline; Mahler, Hanns-Christian; Friess, Wolfgang

    2017-03-01

    Significant loss of preservative was observed during filling of drug products during filling line stops. This study evaluated the losses of three commonly used preservatives in protein drugs, i.e. benzyl alcohol, phenol, and m-cresol. Concentration losses during static incubation were quantified and interpreted with regard to the potential driving forces for the underlying sorption, diffusion, and desorption steps. Partitioning from the solution into the silicone polymer was identified as the most decisive parameter for the extent of preservative loss. Additionally, the influence of tubing inner diameter, starting concentration as well as silicone tubing type was evaluated. Theoretical calculations assuming equilibrium between solution and tubing inner surface and one-directional diffusion following Fick's first law were used to approximate experimental data. Since significant losses were found already after few minutes, adequate measures must be taken to avoid deviations during filling of preservative-containing protein solutions that may impact product quality or antimicrobial efficacy. As a possible alternative to the highly permeable silicone tubing, a specific make of fluoropolymer tubing was identified being suitable for peristaltic pumps and not showing any preservative losses. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Thermal analysis on x-ray tube for exhaust process

    Science.gov (United States)

    Kumar, Rakesh; Rao Ratnala, Srinivas; Veeresh Kumar, G. B.; Shivakumar Gouda, P. S.

    2018-02-01

    It is great importance in the use of X-rays for medical purposes that the dose given to both the patient and the operator is carefully controlled. There are many types of the X- ray tubes used for different applications based on their capacity and power supplied. In present thesis maxi ray 165 tube is analysed for thermal exhaust processes with ±5% accuracy. Exhaust process is usually done to remove all the air particles and to degasify the insert under high vacuum at 2e-05Torr. The tube glass is made up of Pyrex material, 95%Tungsten and 5%rhenium is used as target material for which the melting point temperature is 3350°C. Various materials are used for various parts; during the operation of X- ray tube these waste gases are released due to high temperature which in turn disturbs the flow of electrons. Thus, before using the X-ray tube for practical applications it has to undergo exhaust processes. Initially we build MX 165 model to carry out thermal analysis, and then we simulate the bearing temperature profiles with FE model to match with test results with ±5%accuracy. At last implement the critical protocols required for manufacturing processes like MF Heating, E-beam, Seasoning and FT.

  14. Ceramic vacuum tubes for geothermal well logging

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, R.D.

    1977-01-01

    Useful design data acquired in the evaluation of ceramic vacuum tubes for the development of a 500/sup 0/C instrumentation amplifier are presented. The general requirements for ceramic vacuum tubes are discussed for application to the development of high temperature well logs. Commercially available tubes are described and future contract activities that specifically relate to ceramic vacuum tubes are detailed. Supplemental data are presented in the appendix.

  15. Manual tube-to-tubesheet welding torch

    Science.gov (United States)

    Kiefer, Joseph H.; Smith, Danny J.

    1982-01-01

    A welding torch made of a high temperature plastic which fits over a tube intermediate the ends thereof for welding the juncture between the tube and the back side of a tube plate and has a ballooned end in which an electrode, filler wire guide, fiber optic bundle, and blanketing gas duct are disposed.

  16. Heat exchanger with a removable tube section

    Science.gov (United States)

    Wolowodiuk, W.; Anelli, J.

    1975-07-29

    A heat exchanger is described in which the tube sheet is secured against primary liquid pressure, but which allows for easy removal of the tube section. The tube section is supported by a flange which is secured by a number of shear blocks, each of which extends into a slot which is immovable with respect to the outer shell of the heat exchanger. (auth)

  17. The Fuge Tube Diode Array Spectrophotometer

    Science.gov (United States)

    Arneson, B. T.; Long, S. R.; Stewart, K. K.; Lagowski, J. J.

    2008-01-01

    We present the details for adapting a diode array UV-vis spectrophotometer to incorporate the use of polypropylene microcentrifuge tubes--fuge tubes--as cuvettes. Optical data are presented validating that the polyethylene fuge tubes are equivalent to the standard square cross section polystyrene or glass cuvettes generally used in…

  18. Feasibility Test with a STS304 tube of the Eddy Current Test using a Bobbin Probe for the SMART SG Tube Inspection

    International Nuclear Information System (INIS)

    Lee, Yoon Sang; Jung, Hyun Kyu; Choung, Yun Hang

    2010-01-01

    The SMART SG tubes will be made of Alloy 690. The outside diameter will be 17 mm and the thickness will be 2.5 mm. They will be assembled helically around, and their innermost diameter will be about 600 mm and the total length will be about 32 meters. For the sake of safety, SMART SG tubes are designed for use with thick tubes such as 2.5 mm thickness compared to about 1 mm thickness of normal Korean standard pressurized water reactor tubes. Due to using thick tubes such as the 2.5 mm varieties, it was doubted that the Eddy Current Testing Method (ECT) would be a feasible method. Therefore we are trying to check the feasibility of the ECT using the substitute material STS304 tube instead of Alloy 690 tubes with the bobbin type ECT probe. The previous paper reported the feasibility of the ECT using modeling, but this paper will report the preliminary experimental results and comparison with the previous results of the modeling for the STS304 tube

  19. Morphomechanics: transforming tubes into organs.

    Science.gov (United States)

    Taber, Larry A

    2014-08-01

    After decades focusing on the molecular and genetic aspects of organogenesis, researchers are showing renewed interest in the physical mechanisms that create organs. This review deals with the mechanical processes involved in constructing the heart and brain, concentrating primarily on cardiac looping, shaping of the primitive brain tube, and folding of the cerebral cortex. Recent studies suggest that differential growth drives large-scale shape changes in all three problems, causing the heart and brain tubes to bend and the cerebral cortex to buckle. Relatively local changes in form involve other mechanisms such as differential contraction. Understanding the mechanics of organogenesis is central to determining the link between genetics and the biophysical creation of form and structure. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Microwave discharges in capillary tubes

    International Nuclear Information System (INIS)

    Dervisevic, Emil

    1984-01-01

    This research thesis aims at being a contribution to the study of microwave discharge by a surface wave, and more precisely focusses on the discharge in capillary tubes filled with argon. The author first present theoretical models which describe, on the one hand, the propagation of the surface wave along the plasma column, and, on the other hand, longitudinal and radial profiles of the main discharge characteristics. The second part addresses the study of the influence of parameters (gas pressure and tube radius) on discharge operation and characteristics. Laws of similitude as well as empirical relationships between argon I and argon II emission line intensities, electron density, and electric field in the plasma have been established [fr

  1. Scintillation counter: photomultiplier tube alignment

    International Nuclear Information System (INIS)

    Olson, R.E.

    1975-01-01

    A scintillation counter, particularly for counting gamma ray photons, includes a massive lead radiation shield surrounding a sample-receiving zone. The shield is disassembleable into a plurality of segments to allow facile installation and removal of a photomultiplier tube assembly, the segments being so constructed as to prevent straight-line access of external radiation through the shield into the sample receiving zone. Provisions are made for accurately aligning the photomultiplier tube with respect to one or more sample-transmitting bores extending through the shield to the sample receiving zone. A sample elevator, used in transporting samples into the zone, is designed to provide a maximum gamma-receiving aspect to maximize the gamma detecting efficiency. (auth)

  2. Ionization tube simmer current circuit

    Science.gov (United States)

    Steinkraus, R.F. Jr.

    1994-12-13

    A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current. 6 figures.

  3. ATLAS Muon Drift Tube Electronics

    Energy Technology Data Exchange (ETDEWEB)

    Arai, Y [KEK, High Energy Accelerator Research Organisation, Tsukuba (Japan); Ball, B; Chapman, J W; Dai, T; Ferretti, C; Gregory, J [University of Michigan, Department of Physics, Ann Arbor, MI (United States); Beretta, M [INFN Laboratori Nazionali di Frascati, Frascati (Italy); Boterenbrood, H; Jansweijer, P P M [Nikhef National Institute for Subatomic Physics, Amsterdam (Netherlands); Brandenburg, G W; Fries, T; Costa, J Guimaraes da; Harder, S; Huth, J [Harvard University, Laboratory for Particle Physics and Cosmology, Cambridge, MA (United States); Ceradini, F [INFN Roma Tre and Universita Roma Tre, Dipartimento di Fisica, Roma (Italy); Hazen, E [Boston University, Physics Department, Boston, MA (United States); Kirsch, L E [Brandeis University, Department of Physics, Waltham, MA (United States); Koenig, A C [Radboud University Nijmegen/Nikhef, Dept. of Exp. High Energy Physics, Nijmegen (Netherlands); Lanza, A [INFN Pavia, Pavia (Italy); Mikenberg, G [Weizmann Institute of Science, Department of Particle Physics, Rehovot (Israel)], E-mail: brandenburg@physics.harvard.edu (and others)

    2008-09-15

    This paper describes the electronics used for the ATLAS monitored drift tube (MDT) chambers. These chambers are the main component of the precision tracking system in the ATLAS muon spectrometer. The MDT detector system consists of 1,150 chambers containing a total of 354,000 drift tubes. It is capable of measuring the sagitta of muon tracks to an accuracy of 60 {mu}m, which corresponds to a momentum accuracy of about 10% at p{sub T}= 1 TeV. The design and performance of the MDT readout electronics as well as the electronics for controlling, monitoring and powering the detector will be discussed. These electronics have been extensively tested under simulated running conditions and have undergone radiation testing certifying them for more than 10 years of LHC operation. They are now installed on the ATLAS detector and are operating during cosmic ray commissioning runs.

  4. ATLAS Muon Drift Tube Electronics

    CERN Document Server

    Arai, Y; Beretta, M; Boterenbrood, H; Brandenburg, G W; Ceradini, F; Chapman, J W; Dai, T; Ferretti, C; Fries, T; Gregory, J; Guimarães da Costa, J; Harder, S; Hazen, E; Huth, J; Jansweijer, P P M; Kirsch, L E; König, A C; Lanza, A; Mikenberg, G; Oliver, J; Posch, C; Richter, R; Riegler, W; Spiriti, E; Taylor, F E; Vermeulen, J; Wadsworth, B; Wijnen, T A M

    2008-01-01

    This paper describes the electronics used for the ATLAS monitored drift tube (MDT) chambers. These chambers are the main component of the precision tracking system in the ATLAS muon spectrometer. The MDT detector system consists of 1,150 chambers containing a total of 354,000 drift tubes. It is capable of measuring the sagitta of muon tracks to an accuracy of 60 microns, which corresponds to a momentum accuracy of about 10% at pT = 1 TeV. The design and performance of the MDT readout electronics as well as the electronics for controlling, monitoring and powering the detector will be discussed. These electronics have been extensively tested under simulated running conditions and have undergone radiation testing certifying them for more than 10 years of LHC operation. They are now installed on the ATLAS detector and are operating during cosmic ray commissioning runs.

  5. Origami interleaved tube cellular materials

    International Nuclear Information System (INIS)

    Cheung, Kenneth C; Tachi, Tomohiro; Calisch, Sam; Miura, Koryo

    2014-01-01

    A novel origami cellular material based on a deployable cellular origami structure is described. The structure is bi-directionally flat-foldable in two orthogonal (x and y) directions and is relatively stiff in the third orthogonal (z) direction. While such mechanical orthotropicity is well known in cellular materials with extruded two dimensional geometry, the interleaved tube geometry presented here consists of two orthogonal axes of interleaved tubes with high interfacial surface area and relative volume that changes with fold-state. In addition, the foldability still allows for fabrication by a flat lamination process, similar to methods used for conventional expanded two dimensional cellular materials. This article presents the geometric characteristics of the structure together with corresponding kinematic and mechanical modeling, explaining the orthotropic elastic behavior of the structure with classical dimensional scaling analysis. (paper)

  6. The comparison of corrosion resistance between Baosteel's alloy 690 tube and foreign alloy 690 tube

    International Nuclear Information System (INIS)

    Ma Mingjuan; Zhang Lefu; Li Yan

    2012-01-01

    Alloy 690 having excellent corrosion resistance is widely used for SG tubes. The intergranular corrosion and pitting corrosion resistance of Baosteel's alloy 690 tube, Country A alloy 690 tube and Country B alloy 690 tube have been analysed by comparison. It shows that: The intergranular corrosion of Baosteel's alloy 690 tube tested complied with ASTM G28 Standard could satisfy the technical requirement. However.some of Baosteel's alloy 690 tube in intergranular corrosion resistance had less performance than Country A. In addition, pitting corrosion tested with ASTM G48 Standard shown the Baosteel's alloy 690 tube better than Country B. (authors)

  7. Dynamic characteristics of heat exchanger tubes vibrating in a tube support plate inactive mode

    International Nuclear Information System (INIS)

    Jendrzejczyk, J.A.

    1985-01-01

    Tubes in shell-and-tube heat exchangers, including nuclear plant steam generators, derive their support from longitudinally positioned tube support plates (TSPs). Typically there is a clearance between the tube and TSP hole. Depending on design and fabrication tolerances, the tube may or may not contact all of the TSPs. Noncontact results in an inactive TSP which can lead to detrimental flow induced tube vibrations under certain conditions dependent on the resulting tube-TSP interaction dynamics and the fluid excitation forces. The purpose of this study is to investigate the tube-TSP interaction dynamics. Results of an experimental study of damping and natural frequency as functions of tube-TSP diametral clearance and TSP thickness are reported. Calculated values of damping ratio and frequency of a tube vibrating within an inactive TSP are also presented together with a comparison of calculated and experimetnal quantities

  8. Advanced pressure tube sampling tools

    International Nuclear Information System (INIS)

    Wittich, K.C.; King, J.M.

    2002-01-01

    Deuterium concentration is an important parameter that must be assessed to evaluate the Fitness for service of CANDU pressure tubes. In-reactor pressure tube sampling allows accurate deuterium concentration assessment to be made without the expenses associated with fuel channel removal. This technology, which AECL has developed over the past fifteen years, has become the standard method for deuterium concentration assessment. AECL is developing a multi-head tool that would reduce in-reactor handling overhead by allowing one tool to sequentially sample at all four axial pressure tube locations before removal from the reactor. Four sets of independent cutting heads, like those on the existing sampling tools, facilitate this incorporating proven technology demonstrated in over 1400 in-reactor samples taken to date. The multi-head tool is delivered by AECL's Advanced Delivery Machine or other similar delivery machines. Further, AECL has developed an automated sample handling system that receives and processes the tool once out of the reactor. This system retrieves samples from the tool, dries, weighs and places them in labelled vials which are then directed into shielded shipping flasks. The multi-head wet sampling tool and the automated sample handling system are based on proven technology and offer continued savings and dose reduction to utilities in a competitive electricity market. (author)

  9. Neutron noise to detect BWR-4 in-core instrument tube vibrations and impacting

    International Nuclear Information System (INIS)

    Fry, D.N.; Kryter, R.C.; Mathis, M.V.; Mott, J.E.; Robinson, J.C.

    1979-01-01

    Noise analysis was used to investigate in-core instrument tube vibrations in boiling water reactor-4 (BWR-4)-type reactors. Neutron noise signals from in-core fission chambers and acoustic noise signals from externally mounted accelerometers were used in these studies. The results show that neutron noise can be used to detect vibration and, more important, impacting of instrument tubes against adjacent fuel channel boxes. Externally mounted accelerometers detect impacting but not rubbing of instrument tubes against fuel channel boxes. Accelerometers can monitor impacting only on the particular instrument tube where the accelerometer is mounted. Surveillance for instrument tube impacts can be accomplished using standard BWR-4 in-core power range neutron flux detectors at all instrument tube locations containing these detectors. Ex-vessel accelerometers can then be used to monitor instrument tubes that lack power range neutron flux detectors. However, noise on axial flux profiles obtained with movable in-core detectors is not a reliable indicator of impacting because the recorder used to plot the flux profiles does not respond adequately to the noise frequency generated by impacting. Neutron noise signatures show that modification of the bypass cooling by plugging preexisting holes and drilling new holes in the fuel assembly lower tie plate greatly reduces instrument tube vibration and eliminates impacting of instrument tubes against fuel boxes

  10. The Effects of Glucose Therapy Agents-Apple Juice, Orange Juice, and Cola-on Enteral Tube Flow and Patency.

    Science.gov (United States)

    Steinberg, Daphna J; Montreuil, Jasmine; Santoro, Andrea L; Zettas, Antonia; Lowe, Julia

    2016-06-01

    To develop evidence-based hypoglycemia treatment protocols in patients receiving total enteral nutrition, this study determined the effect on enteral tube flow of glucose therapy agents: apple juice, orange juice, and cola, and it also examined the effects of tube type and feed type with these glucose therapy agents. For this study, 12 gastrostomy tubes (6 polyethylene and 6 silicone) were set at 50 mL/h. Each feeding set was filled with Isosource HN with fibre or Novasource Renal. Each tube was irrigated with 1 glucose therapy agent, providing approximately 20 g of carbohydrate every 4 h. Flow-rate measurements were collected at 2 h intervals. The results showed that the glucose therapy agent choice affected flow rates: apple juice and cola had higher average flow rates than orange juice (P = 0.01). A significant difference was found between tube type and enteral formula: polyethylene tubes had higher average flow rates than silicone tubes (P juice and cola have less tube clogging potential than orange juice, and thus may be considered as primary treatment options for hypoglycemia in enterally fed patients. Polyethylene tubes and Isosource HN with fibre were less likely to clog than silicone tubes and Novasource Renal.

  11. The Impact of Tympanostomy Tubes on Speech and Language Development in Children with Cleft Palate.

    Science.gov (United States)

    Shaffer, Amber D; Ford, Matthew D; Choi, Sukgi S; Jabbour, Noel

    2017-09-01

    Objective Describe the impact of hearing loss, tympanostomy tube placement before palatoplasty, and number of tubes received on speech outcomes in children with cleft palate. Study Design Case series with chart review. Setting Tertiary care children's hospital. Subjects and Methods Records from 737 children born between April 2005 and April 2015 who underwent palatoplasty at a tertiary children's hospital were reviewed. Exclusion criteria were cleft repair at an outside hospital, intact secondary palate, absence of postpalatoplasty speech evaluation, sensorineural or mixed hearing loss, no tubes, first tubes after palatoplasty, or first clinic after 12 months of age. Data from 152 patients with isolated cleft palate and 166 patients with cleft lip and palate were analyzed using Wilcoxon rank-sum, χ 2 , and Fisher exact test and logistic regression. Results Most patients (242, 76.1%) received tubes before palatoplasty. Hearing loss after tubes, but not before, was associated with speech/language delays at 24 months ( P = .005) and language delays ( P = .048) and speech sound production disorders (SSPDs, P = .040) at 5 years. Receiving tubes before palatoplasty was associated with failed newborn hearing screen ( P = .001) and younger age at first posttubes type B tympanogram with normal canal volume ( P = .015). Hearing loss after tubes ( P = .021), language delays ( P = .025), SSPDs ( P = .003), and velopharyngeal insufficiency ( P = .032) at 5 years and speech surgery ( P = .022) were associated with more tubes. Conclusion Continued middle ear disease, reflected by hearing loss and multiple tubes, may impair speech and language development. Inserting tubes before palatoplasty did not mitigate these impairments better than later tube placement.

  12. Česká YouTube scéna

    OpenAIRE

    NEMRAVOVÁ, Barbora

    2017-01-01

    The aim of this bachelor thesis is to introduce Czech YouTubers, the internet celebrities, to the readers. It is focused on marketing strategies by which it is possible to earn money on YouTube. The thesis studies methods like collaborations with companies, sponsoring and YouTube Partner Program in more details. There is a brief history of YouTube mentioned in this thesis and how the webpage works for the users. Also there are described types of videos and types of YouTubers divided by orient...

  13. Tube entrance lens focus control

    Science.gov (United States)

    Weisser, D. C.; Fifield, L. K.; Kitchen, T. F. G.; Tunningley, T. B.; Lobanov, N. R.; Muirhead, A. G.

    2013-02-01

    The entrance of the accelerator tube in a large electrostatic accelerator imposes a strong lens that dominates the beam optics. The magnification of the lens is large because of the low injection energy, the high voltage gradient of the acceleration tube and the long distance to the terminal. In the absence of the acceleration, the magnification would produce an unacceptably large beam spot at the terminal. The tyranny of the lens is especially irksome when the accelerator is required to operate at a lower terminal voltage than the one corresponding to the nominal gradient at high voltage. One way around the difficulty, used in NEC Pelletron accelerators, is to insert a series of nylon and steel rods that short together units of the acceleration structure at the terminal leaving the ones near the entrance close to the nominal gradient for optimum transmission. This operation takes time and risks the loss of insulating gas. Another alternative used in the 25URC at Oak Ridge National Laboratory, is to focus the beam at the tube entrance, substantially diluting the effect of the entrance lens. The beam then diverges and so requires an additional lens part way to the terminal. This solution is only partially effective and still necessitates use of shorting rods for low voltage operation. The fact that these elaborate strategies are used is evidence that the alternative of lowering the injection energy as the terminal voltage is lowered imposes enough problems that it is not used in practice. We have modeled a solution that controls the voltage gradient at the tube entrance using an external power supply. This not only maintains the focusing effect of the lens but provides the opportunity to tune the beam by adjusting the entrance lens. A 150 kV power supply outside the pressure vessel feeds a controllable voltage through a high voltage feed-through to the fifth electrode of the accelerator tube. Thus 150 kV on this electrode creates the nominal gradient of 30 kV per

  14. 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.

  15. 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.

  16. Oxymetazoline is equivalent to ciprofloxacin in preventing postoperative otorrhea or tympanostomy tube obstruction.

    Science.gov (United States)

    Kumar, Veena V; Gaughan, John; Isaacson, Glenn; Szeremeta, Wasyl

    2005-02-01

    To compare the effectiveness of ciprofloxacin and oxymetazoline solutions instilled after tympanostomy tube placement in the prevention of postoperative otorrhea and tube occlusion. Prospective cross-sectional series. We reviewed all bilateral myringotomy and tube placement operations performed by two full-time attending pediatric otolaryngologists during a 9 month period. Data from 488 patients who underwent surgery for otitis media were collected. Demographic and clinical variables including age, sex, number of tube insertions in the past, previous adenoidectomy, type of effusion present at surgery, and type of drop prescribed postoperatively were recorded. All patients were evaluated in the office 2 to 4 weeks postoperatively. Multivariate logistic regression analysis was used to estimate the relationship of these variables with the occurrence of otorrhea and tube patency. Odds ratios were calculated. No significant differences in postoperative otorrhea or tube patency were found between ciprofloxacin (Ciloxan) and oxymetazoline solutions (Afrin, Visine LR). Oxymetazoline and ciprofloxacin solutions are equivalent in the prevention of postoperative otorrhea and tube occlusion after tympanostomy tube placement. The implications for medication cost and potential adverse reactions are discussed.

  17. Eddy current test of fin tubes for a heat exchanger

    International Nuclear Information System (INIS)

    KIm, Young Joo; Lee, Se Kyung; Chung, Min Hwa

    1992-01-01

    Eddy current probes were designed for the test of fin tubes. Fin tubes, often used for heat exchangers, have uneven outer and inner surfaces to enhance the heat emission. The surface roughness make it difficult to detect flaws employing eddy current test(ECT). In order to overcome the difficulties we performed two types of works, one is the delopment of ECT probes, and the other is the signal processing including fast Fourier transform and digital filtering. In the development of ECT probes, we adopted empirical design method. Our ECT probes for fin tubes are inside diameter type. And we are specially concerned about geometric features such as the widths of the coils composing an ECT probe. We fabricated four probes with various coil widths. Eddy current test was performed using those ECT probes on specimens with artificial flaws. After analyzing the output signals, we found that, in order for the effective testing, the width of a coil should be determined considering the pitch of the fins of a tube. And we also learned that the frequency filtering could improve the s/n ratio.

  18. Non-destructive evaluation of stream generator tubes and pressure tubes from the PHWR reactors, using the rotating magnetic field method

    International Nuclear Information System (INIS)

    Premel, D.; Placko, D.; Grimberg, R.; Savin, A.

    2001-01-01

    This work presents a new type of eddy current transducer with a rotating magnetic field devoted to the inspection of steam generator tubes and pressure tubes from the PHWR reactors. A theoretical model has been developed that permits the calculations of the emf induced in the reception coils in the presence of the copper or magnetite deposits, anti-vibration railing and garter springs. (authors)

  19. Method for estimating off-axis pulse tube losses

    Science.gov (United States)

    Fang, T.; Mulcahey, T. I.; Taylor, R. P.; Spoor, P. S.; Conrad, T. J.; Ghiaasiaan, S. M.

    2017-12-01

    Some Stirling-type pulse tube cryocoolers (PTCs) exhibit sensitivity to gravitational orientation and often exhibit significant cooling performance losses unless situated with the cold end pointing downward. Prior investigations have indicated that some coolers exhibit sensitivity while others do not; however, a reliable method of predicting the level of sensitivity during the design process has not been developed. In this study, we present a relationship that estimates an upper limit to gravitationally induced losses as a function of the dimensionless pulse tube convection number (NPTC) that can be used to ensure that a PTC would remain functional at adverse static tilt conditions. The empirical relationship is based on experimental data as well as experimentally validated 3-D computational fluid dynamics simulations that examine the effects of frequency, mass flow rate, pressure ratio, mass-pressure phase difference, hot and cold end temperatures, and static tilt angle. The validation of the computational model is based on experimental data collected from six commercial pulse tube cryocoolers. The simulation results are obtained from component-level models of the pulse tube and heat exchangers. Parameter ranges covered in component level simulations are 0-180° for tilt angle, 4-8 for length to diameter ratios, 4-80 K cold tip temperatures, -30° to +30° for mass flow to pressure phase angles, and 25-60 Hz operating frequencies. Simulation results and experimental data are aggregated to yield the relationship between inclined PTC performance and pulse tube convection numbers. The results indicate that the pulse tube convection number can be used as an order of magnitude indicator of the orientation sensitivity, but CFD simulations should be used to calculate the change in energy flow more accurately.

  20. Cases of fallopian tube prolapse

    Directory of Open Access Journals (Sweden)

    Sushil Chawla

    2015-01-01

    Full Text Available Fallopian tube prolapse post hysterectomy is rarely reported complication which can lead to doubts in the mind of young and experienced surgeons alike. This leads to patient morbidity and gets different medical treatments ranging from antibiotics to local applications of copper sulphate, without relief. The use of proper surgical technique, prevention of post operative hematoma and infection go a long way in its prevention.We hereby present two cases, which were manged successfully to relieve the patients of their agony.

  1. Eddy current inspection of tubing

    International Nuclear Information System (INIS)

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

    1966-01-01

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

  2. Measurement of Work Generation and Improvement in Performance of a Pulse Tube Engine

    Science.gov (United States)

    Hamaguchi, Kazuhiro; Futagi, Hiroaki; Yazaki, Taichi; Hiratsuka, Yoshikatsu

    Apart from double acting type engines, Stirling engines have either 2 pistons in 2 cylinders or 2 pistons in a single cylinder. Typically, the heater, regenerator and cooler are installed between the 2 pistons. The pulse tube engine, on the other hand, consists of a single piston in a single cylinder, a pulse tube, a heater, a regenerator, a cooler and a second cooler. For this paper, a simple prototype engine that uses air at normal atmospheric pressure as the working gas was fabricated. The oscillating velocity of the working gas in the pulse tube was measured using LDV, and the work flow emitting out of the pulse tube was observed. In addition, the effect of inserting heat storage material in the pulse tube on shaft power and indicated power was examined experimentally. A dramatic increase in the shaft power was achieved.

  3. Viability of use of PVC tubes in solar collectors: an analysis of materials

    Directory of Open Access Journals (Sweden)

    Luiz Guillherme Meira de Souza

    2003-06-01

    Full Text Available This paper presents a study of the inherent degradations of PVC tubes due to the thermal effect and ultraviolet solar radiation. The approach relates its causes and its effect of use of the PVC tubes as elements to absorption, forming a coil, in solar collectors for water heating. It is demonstrated that such degradations can be burst through the use of an outflow and an appropriate regimen of work, as well as of a protective layer for the tubes, in this case black ink used to magnify its absorption. The results of the properties of tubes that had been exposed to the degradation effect for up to five years are presented. The viability of use of this type of collector is demonstrated through comparative analysis of tubes exposed and not exposed to the sun, concluding for the low cost, easy assembly and maintenance of the system.

  4. Study of Temperature Fields at Sprinkled Smooth and Sandblasted Tube Bundle

    Directory of Open Access Journals (Sweden)

    Kracík Petr

    2014-03-01

    Full Text Available The paper focuses on the influence of sprinkled tube surface on distribution of temperature fields, i.e. the heat transfer coefficient on the tubes surface. Two types of tubes have been tested, a smooth one and a sandblasted one in particular. A tube bundle comprises of thirteen copper tubes divided into two rows and it is located in a low pressure chamber where vacuum is generated using an exhauster via ejector. The liquid tested was water at an absolute pressure in a chamber in between 97 kPa up to 10 kPa and a thermal gradient 55 to 30 °C. The flow of the falling film liquid ranged between zero and 17 litres per minute.

  5. Temperature control of thermal-gas-dynamical installation in cleaning oil-well tubes

    Science.gov (United States)

    Penner, V. A.; Martemyanov, D. B.; Pshenichnikova, V. V.

    2017-08-01

    The article provides the study results of cleaning oil-well tubes, the oil-well tube failure reasons for service by their types have been considered. The chemical method of cleaning oil-well tubes as the least expensive has been reviewed when acid solution moves to the interptube space mixing up with oil and liquidates paraffin and pitches deposits on the internal pipe surface. Except the chemical method of pipes cleaning the mechanical one was considered as well. Also the disadvantages -such as the low productivity of cleaning and design complexity- of this deposits removal method on the internal oil-well tube surface have been considered. An effective method for cleaning oil-well tubing from paraffin and pitches by the thermodynamic plant based on the aircraft engine has been introduced for the first time. The temperature distribution graph in the gas stream at the engine output has been given.

  6. The efficacy of test tube warming devices used during oocyte retrieval for IVF.

    Science.gov (United States)

    Yeung, Queenie Sum Yee; Briton-Jones, Christine May; Tjer, Grace Ching Ching; Chiu, Tony Tak Yu; Haines, Christopher

    2004-10-01

    To investigate whether commonly used test tube warming devices maintain a constant temperature in follicular fluid aspirates. By using a digital thermocouple, temperature was measured and comparisons were made between an analog dry block heater, a digital dry block heater, and a thermostatic test tube heater. For small fluid volumes, temperature in the block heaters increased above 37 degrees C after being in the block for over 2 min. The thermostatic heater maintained a constant temperature, but this was below the factory setting of 36.9 degrees C. Temperature maintenance was influenced by fluid volume in each tube. One of the key factors in the handling of gametes and embryos is the maintenance of constant temperature. Test tube warming devices require verification of their ability to maintain fluid at the desired temperature. Temperature may vary with fluid volume and the type of test tube warming device used.

  7. Multi-walled carbon nano-tubes for energy storage and production applications

    International Nuclear Information System (INIS)

    Andrews, R.; Jacques, D.; Likpa, S.; Qian, D.; Rantell, T.; Anthony, J.

    2005-01-01

    pattern both n-type and p-type MWNTs on suitable electrode substrates, with most effort concentrated on patterning these nano-tube arrays on transparent or flexible substrates. Work bas included the preparation of inter-digitated arrays of p-type and n-type nano-tubes, or arrays of n-type nano-tubes intermixed with p-type organic semiconductor, for studies of photovoltaic properties of such systems. In this presentation, the synthesis, characterization and use of differing types of nano-tube materials will be described, as well as their performance in photovoltaic applications. Particular emphasis will be placed on large scale growth methods for in situ device formation, control of the nano-tube interface, and chemical functionalization of nano-tubes to improve system performance. (authors)

  8. Survival times with and without tube feeding in patients with dementia or psychiatric diseases in Japan.

    Science.gov (United States)

    Takayama, Keiko; Hirayama, Keisuke; Hirao, Akihiko; Kondo, Keiko; Hayashi, Hideki; Kadota, Koichi; Asaba, Hiroyuki; Ishizu, Hideki; Nakata, Kenji; Kurisu, Kairi; Oshima, Etsuko; Yokota, Osamu; Yamada, Norihito; Terada, Seishi

    2017-11-01

    It is widely supposed that there has been no evidence of increased survival in patients with advanced dementia receiving enteral tube feeding. However, more than a few studies have reported no harmful outcome from tube feeding in dementia patients compared to in patients without dementia. This was a retrospective study. Nine psychiatric hospitals in Okayama Prefecture participated in this survey. All inpatients fulfilling the entry criteria were evaluated. All subjects suffered from difficulty with oral intake. Attending physicians thought that the patients could not live without long-term artificial nutrition. The physicians decided whether to make use of long-term artificial nutrition between January 2012 and December 2014. We evaluated 185 patients. Their mean age was 76.6 ± 11.4 years. Of all subjects, patients with probable Alzheimer's disease (n = 78) formed the biggest group, schizophrenia patients (n = 44) the second, and those with vascular dementia (n = 30) the third. The median survival times were 711 days for patients with tube feeding and 61 days for patients without tube feeding. In a comparison different types of tube feeding, median survival times were 611 days for patients with a nasogastric tube and more than 1000 days for those with a percutaneous endoscopic gastrostomy tube. Patients with tube feeding survived longer than those without tube feeding, even among dementia patients. This study suggests that enteral nutrition for patients with dementia prolongs survival. Additionally, percutaneous endoscopic gastrostomy tube feeding may be safer than nasogastric tube feeding among patients in psychiatric hospitals. © 2017 Japanese Psychogeriatric Society.

  9. Heat transfer performance of condenser tubes in an MSF desalination system

    International Nuclear Information System (INIS)

    Galal, T.; Kalendar, A.; Al Saftawi, A.; Zedan, M.

    2010-01-01

    The present research examines the amount of condensed fresh water off the outer-side surface of heat exchangers in an MSF system. The quantitative modeling of condensed water on the outer surface of comparable tubes, enhanced and plain, in a simulated MSF technique is investigated. An adapted simulation design on a test-rig facility, accounting for the condenser tubing in actual industrial desalination plate-form, is used with corrugated and smooth aluminum-brass material tubes 1100mm long and 23mm bore. A single phase flow of authentic brine water that typifies real fouling is utilized to simulate the actual environmental life of a multi-stage flashing desalination system, with coolant flow velocity 0.1 m/s in the two delineated types of condenser tubing. It is demonstrated that the condensate water amount from the specified enhanced tube is about 1.22 times the condensate water amount from the smooth tube, adaptive for 140 running hours under deliberated constrains. The topic covers a comparative analysis of thermal performance. Comparing results with fresh water confirm the effect of fouling on significantly lowering the value of the overall heat transfer coefficient versus time. Fouling resistance R f is reported with the critical coolant flow speed of 0.1 m/s. Comparison between the fouling resistance for both smooth and corrugated tubes versus time is performed. The fouling thermal resistance of the corrugated tube is 0.56 of the fouling thermal resistance of the smooth tube after140 running hours of the experiment are concluded. Overall, in the case of real brine, results prove that heat performance for the corrugated tube is superior to the plain tube over the studied time period (140 hrs) for the chosen range of flow speeds

  10. Unjoined primary and secondary neural tubes: junctional neural tube defect, a new form of spinal dysraphism caused by disturbance of junctional neurulation.

    Science.gov (United States)

    Eibach, Sebastian; Moes, Greg; Hou, Yong Jin; Zovickian, John; Pang, Dachling

    2017-10-01

    Primary and secondary neurulation are the two known processes that form the central neuraxis of vertebrates. Human phenotypes of neural tube defects (NTDs) mostly fall into two corresponding categories consistent with the two types of developmental sequence: primary NTD features an open skin defect, an exposed, unclosed neural plate (hence an open neural tube defect, or ONTD), and an unformed or poorly formed secondary neural tube, and secondary NTD with no skin abnormality (hence a closed NTD) and a malformed conus caudal to a well-developed primary neural tube. We encountered three cases of a previously unrecorded form of spinal dysraphism in which the primary and secondary neural tubes are individually formed but are physically separated far apart and functionally disconnected from each other. One patient was operated on, in whom both the lumbosacral spinal cord from primary neurulation and the conus from secondary neurulation are each anatomically complete and endowed with functioning segmental motor roots tested by intraoperative triggered electromyography and direct spinal cord stimulation. The remarkable feature is that the two neural tubes are unjoined except by a functionally inert, probably non-neural band. The developmental error of this peculiar malformation probably occurs during the critical transition between the end of primary and the beginning of secondary neurulation, in a stage aptly called junctional neurulation. We describe the current knowledge concerning junctional neurulation and speculate on the embryogenesis of this new class of spinal dysraphism, which we call junctional neural tube defect.

  11. X-ray tube transformer

    International Nuclear Information System (INIS)

    1980-01-01

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

  12. 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.

  13. Fluoroscopic placement of jejunal feeding tubes

    International Nuclear Information System (INIS)

    Hoffer, F.; Mandell, V.S.; Sandler, R.H.; Leichner, A.; Kaplan, L.C.; Haynie, M.

    1992-01-01

    Over a two-and-one-half year period, 50 children underwent placements of jejunal tubes through a nasal route (NJ, n=47) or through an existing gastrostomy site (GJ, n=119). There were four attempted placements (98% success rate). The NJ tubes remained in place an average of 13 days, and the GJ tubes remained in place an average of 37 days. Fluoroscopic time for placement of an NJ tube an averaged 6 min (29 cases) and for a GJ tube 8 minutes (91 cases). In spite of the limited retention time, fluoroscopic time, and availability of alternative methods, fluoroscopically placed jejunal feedings tubes are still playing an active role in this institution. (orig.)

  14. Tube bundle vibrations in transversal flow

    International Nuclear Information System (INIS)

    Gibert, R.J.; Sagner, M.

    1978-01-01

    This study gives important information concerning characteristic parameters about lock-in and whirling instability phenomena, in the case of tube arrays. The work is mainly an experimental one though models are also developed: 1) an equilateral pitch bundle (p=1,5 D with D=tube diameter) is tested. Tube damping (epsilon) and first eigenfrequency (f), flow velocity are explored in a large domain. Vibratory level of the tubes are measured and critical points are ploted on the fluidelastic parameters diagram. Several bundles with various usual pitches and arrangements (in line or staggered) are tested. Critical velocities are measured and the whirling instability characteristic coefficient is tabulated. A complementary experiment is made on tube rows with various pitches. This gives valuable informations concerning the look-in domain in VR and A'R diagram. Furthermore this puts in evidence the important effect of a frequency difference between two adjacent tubes on the whirling critical velocity

  15. Why do aged fluorescent tubes flicker?

    Science.gov (United States)

    Plihon, Nicolas; Ferrand, Jérémy; Guyomar, Tristan; Museur, Flavien; Taberlet, Nicolas

    2017-11-01

    Our everyday experience of aged and defective fluorescent tubes or bulbs informs us that they may flicker and emit a clicking sound while struggling to light up. In this article, the physical mechanisms controlling the initial illumination of a functioning fluorescent tube are investigated using a simple and affordable experimental setup. Thermionic emission from the electrodes of the tube controls the startup of fluorescent tubes. The origin of the faulty startup of aged fluorescent tubes is discussed and flickering regimes using functional tubes are artificially produced using a dedicated setup that decreases electron emission by the thermionic effect in a controlled manner. The physical parameters controlling the occurrence of flickering light are discussed, and their temporal statistics are reported.

  16. Detection of steam generator tube leaks in pressurized water reactors

    International Nuclear Information System (INIS)

    Roach, W.H.

    1984-11-01

    This report addresses the early detection of small steam generator tube leaks in pressurized water reactors. It identifies physical parameters, establishes instrumentation performance goals, and specifies sensor types and locations. It presents a simple algorithm that yields the leak rate as a function of known or measurable quantities. Leak rates of less than one-tenth gram per second should be detectable with existing instrumentation

  17. Some characteristics of the long straw drift tubes

    International Nuclear Information System (INIS)

    Bychkov, V.N.; Kekelidze, G.D.; Ivanov, A.B.; Livinskij, V.V.; Lobastov, S.P.; Lysan, V.M.; Mishin, S.V.; Peshekhonov, V.D.

    1998-01-01

    This article represents the construction and testing of the long straw drift tubes of different types. The diameter and the length of each straw were equal to 15 mm and 3 m respectively. The cathode resistance of these straws has a small value, i.e. about 100 Ohm/m. Thus, they do not have a large attenuation length. Installation of the spacers reduces the effective straw length by 0.5 % per meter, at least

  18. Automated addition of Chelex solution to tubes containing trace items

    DEFF Research Database (Denmark)

    Stangegaard, Michael; Hansen, Thomas Møller; Hansen, Anders Johannes

    2011-01-01

    Extraction of DNA from trace items for forensic genetic DNA typing using a manual Chelex based extraction protocol requires addition of Chelex solution to sample tubes containing trace items. Automated of addition of Chelex solution may be hampered by high viscosity of the solution and fast...... sedimentation rate of the Chelex beads. Here, we present a simple method that can be used on an Eppendorf epMotion liquid handler resolving these issues...

  19. Investigation of Turbulators for Fire Tube Boilers Using Exergy Analysis

    OpenAIRE

    AYHAN, Betül

    2001-01-01

    In this paper, an experimental study of five different types of ``turbulator" inserts for fire tube boilers is presented. The experimental setup was constructed in the Department of Mechanical Engineering Laboratory of Karadeniz Technical University. It was tested to evaluate the boiler efficiency according to TS 4040 standard, and to evaluate the second law efficiency of thermodynamics for the cases with and without inserts under the same operating conditions. Four new typ...

  20. Importance of crevices formed between tubes and tube plate for the operational behaviour of heat exchangers

    International Nuclear Information System (INIS)

    Achten, N.; Herbsleb, G.; Wieling, N.

    1986-01-01

    It must be guaranteed by construction and manufacture of heat exchangers that primary and secondary medium are completely separated from each other. When this requirement is fullfilled, the operational use of heat exchangers can be impaired by corrosion reactions within the crevice formed between tube and tube plate which may result in corrosion damage. The various techniques which are in use to connect tubes and tube plate and which are described in the present report, must be valued with respect to the tightness of the connection as well as to the formation of crevices between tubes and tube plate. Corrosion resistant copperbase alloys and stainless steels are the most important materials which are in use for the construction of heat exchangers. The mechanisms of crevice corrosion with unalloyed and low alloy carbon steels, stainless steels, and mixed connections between tube and tube plate with these materials are described in detail. Crevice corrosion may be caused also by the formation of galvanic cells between materials of differing electrochemical response. Furthermore, the concentration of aggressive media in crevices between tubes and tube plate can lead to corrosion damage of heat exchanger tubes. For the service operation of heat exchangers without any hazard of corrosion damage in crevices between tubes and tube plate, such crevices must be avoided by proper construction and manufacture. As a model for suitable measures to avoid crevices, the manufacture of steam generators for PWR's is described. (orig.) [de

  1. Method of evaluation of stress corrosion cracking susceptibility of clad fuel tubes

    International Nuclear Information System (INIS)

    Takase, Iwao; Yoshida, Toshimi; Ikeda, Shinzo; Masaoka, Isao; Nakajima, Junjiro.

    1986-01-01

    Purpose: To determine, by an evaluation in out-pile test, the stress corrosion cracking susceptibility of clad fuel tubes in the reactor environment. Method: A plurality of electrodes are mounted in the circumferential direction on the entire surface of cladding tubes. Of the electrodes, electrodes at two adjacent places are used as measuring terminals and electrodes at another two places adjacent thereto are used as constant-current terminals. With a specific current flowing in the constant-current terminals, measurements are made of a potential difference between the terminals to be measured, and from a variation in the potential difference the depth of cracking of the cladding tube surface is presumed to determine the stress corrosion cracking susceptibility of the cladding tube. To check the entire surface of the cladding tube, the cladding tube is moved by each block in the circumferential direction by a contact changeover system, repeating the measurements of the potential difference. Contact type electrodes are secured with an insulator and held in uniform contact with the cladding tube by a spring. It is detachable by use of a locking system and movable as desired. Thus the stress corrosion cracking susceptibility can be determined without mounting the cladding tube through and also a fuel failure can be prevented. (Horiuchi, T.)

  2. Preparation of nitrogen-doped carbon tubes

    Science.gov (United States)

    Chung, Hoon Taek; Zelenay, Piotr

    2015-12-22

    A method for synthesizing nitrogen-doped carbon tubes involves preparing a solution of cyanamide and a suitable transition metal-containing salt in a solvent, evaporating the solvent to form a solid, and pyrolyzing the solid under an inert atmosphere under conditions suitable for the production of nitrogen-doped carbon tubes from the solid. Pyrolyzing for a shorter period of time followed by rapid cooling resulted in a tubes with a narrower average diameter.

  3. Vibrations of tube arrays in transversal flow

    International Nuclear Information System (INIS)

    Gibert, R.J.; Doyen, R.

    1981-08-01

    In this study the local forces per unit length acting in a tube in a single row and in bundle have been measured. Their modification by a given harmonic motion of the tube itself or of an adjacent tube has been particularly studied. Some complementary experiments have been performed to extend the whirling coefficient tabulation and also to precise the effect of the upstream velocity profile on the whirling critical velocities [fr

  4. Flow of Jeffrey Fluid through Narrow Tubes

    OpenAIRE

    Nallapu, Santhosh; Radhakrishnamacharya, G.

    2014-01-01

    The present paper deals with a two-fluid model for the flow of Jeffrey fluid in tubes of small diameters. It is assumed that the core region consists of Jeffrey fluid and Newtonian fluid in the peripheral region. Analytical expressions for velocity, effective viscosity, core hematocrit and mean hematocrit have been derived. The effects of various parameters, namely, Jeffrey parameter ({\\lambda}1), tube hematocrit (H0) and tube radius (a) on effective viscosity, core hematocrit and mean hemato...

  5. Shape optimization of draft tubes for Agnew microhydro turbines

    International Nuclear Information System (INIS)

    Shojaeefard, Mohammad Hasan; Mirzaei, Ammar; Babaei, Ali

    2014-01-01

    Highlights: • The draft tube of Agnew microhydro turbine was optimized. • Pareto optimal solutions were determined by neural networks and NSGA-II algorithm. • The pressure recovery factor increases with height and angle over design ranges. • The loss coefficient reaches the minimum values at angles about 2 o . • Swirl of the incoming flow has great influence on the optimization results. - Abstract: In this study, the shape optimization of draft tubes utilized in Agnew type microhydro turbines has been discussed. The design parameters of the draft tube such as the cone angle and the height above the tailrace are considered in defining an optimization problem whose goal is to maximize the pressure recovery factor and minimize the energy loss coefficient of flow. The design space is determined by considering the experimental constraints and parameterized by the method of face-centered uniform ascertain distribution. The numerical simulations are performed using the boundary conditions found from laboratory tests and the obtained results are analyzed to create and validate a feed-forward neural network model, which is implemented as a surrogate model. The optimal Pareto solutions are finally determined using the NSGA-II evolutionary algorithm and compared for different inlet conditions. The results predict that the high swirl of the incoming flow drastically reduces the performance of the draft tube

  6. Tritium application: self-luminous glass tube(SLGT)

    International Nuclear Information System (INIS)

    Kim, K.; Lee, S.K.; Chung, E.S.; Kim, K.S.; Kim, W.S.; Nam, G.J.

    2005-01-01

    To manufacture SLGTs (self-luminous glass tubes), 4 core technologies are needed: coating technology, tritium injection technology, laser sealing/cutting technology and tritium handling technology. The inside of the glass tubes is coated with greenish ZnS phosphor particles with sizes varying from 4∝5 [μm], and Cu, and Al as an activator and a co-dopant, respectively. We also found that it would be possible to produce a phosphor coated glass tube for the SLGT using the well established cold cathode fluorescent lamp (CCFL) bulb manufacturing technology. The conceptual design of the main process loop (PL) is almost done. A delicate technique will be needed for the sealing/cutting of the glass tubes. Instead of the existing torch technology, a new technology using a pulse-type laser is under investigation. The design basis of the tritium handling facilities is to minimize the operator's exposure to tritium uptake and the emission of tritium to the environment. To fulfill the requirements, major tritium handling components are located in the secondary containment such as the glove boxes (GBs) and/or the fume hoods. The tritium recovery system (TRS) is connected to a GB and PL to minimize the release of tritium as well as to remove the moisture and oxygen in the GB. (orig.)

  7. An anti vimentin antibody promotes tube formation

    DEFF Research Database (Denmark)

    Jørgensen, Mathias Lindh; Møller, Carina Kjeldahl; Rasmussen, Lasse

    2017-01-01

    antibody technology, promotes tube formation of endothelial cells in a 2D matrigel assay. By binding vimentin, the antibody increases the tube formation by 21% after 5 hours of incubation. Addition of the antibody directly to cultured endothelial cells does not influence endothelial cell migration...... or proliferation. The enhanced tube formation can be seen for up to 10 hours where after the effect decreases. It is shown that the antibody-binding site is located on the coil 2 domain of vimentin. To our knowledge this is the first study that demonstrates an enhanced tube formation by binding vimentin in a 2D...

  8. Stresses in pin-loaded tubes

    Science.gov (United States)

    Ahmad, Ishtiaq

    This thesis deals with a parametric 3-dimensional photoelastic study of the stresses in pin-loaded tubes, commonly used in securing an aircraft engine into the air frame. Among the geometric variables studied (normalised with reference to the outer tube diameter) are included form values of the ratio of pin-hole diameter to outer tube diameter (0.10, 0.20, 0.40 and 0.60), four different hole-centre positions relative to the tube end and six values of the ratio of tube thickness to outer tube diameter (0.04, 0.08, 0.16, 0.25, 0.32 and 0.50). The other variables investigated are clearance between pin and hole, pin stiffness and lubrication. Some combinations of pairs of pins, either parallel or "crossed" have also been studied, and the effects of different modes of tensile loading, compressive loading, bending loading and torsional loading have been assessed. The results include details of the distribution of normalised changes in tube diameter along the planes of symmetry, the distribution of stress indices around the tube ends, the distribution of stress indices along planes of symmetry and the distribution of stress indices around the pin-loaded holes. The work is discussed in detail. The results provide a valuable reference in the design of pin-loaded tubes.

  9. Failure Analysis of a Service Tube

    Science.gov (United States)

    Xie, Zhongdong; Cai, Weiguo; Li, Zhenxing; Guan, YiMing; Zhang, Baocheng; Yang, XiaoTong

    2017-12-01

    One tube was cracked used in the primary reformer furnace in a fertilizer plant for two and half years. In order to find out the causes of cracking, the methods for chemical composition analysis, macro- and microstructure analysis, penetrant testing, weld analysis, crack and surface damage analysis, mechanics property analysis, high temperature endurance performance analysis, stress and wall thickness calculation were adopted. The integrated assessment results showed that the carbon content of the tube was in the lower limit of the standard range; the tube effective wall thickness was too small; local overheating leads to tube cracking in use process.

  10. Bottom nozzle to guide tube connection

    International Nuclear Information System (INIS)

    Bryan, W.J.

    1991-01-01

    This patent describes a nuclear fuel assembly which includes an upper end fitting and a lower end fitting spaced therefrom and connected thereto by elongated guide tubes of one alloy having an open upper end and a closed lower end with spaced fuel element retaining grids mounted on the guide tubes therebetween, the closed lower ends of the guide tubes including a threaded central passageway and the attachment of the guide tubes to the lower end fitting of another alloy. It comprises: an externally threaded bolt with a first end threadably received in the threaded central passageway of the lower end of the guide tube and a head at the other end of the side of the lower end fitting opposite the guide tube; an interruption in the external threads of the bolt which forms a groove which communicates the interior of the guide tube with the side of the lower end fitting opposite the guide tube and enhances its frictional engagement with the threaded central passageway, thereby to hold and attach the guide tube and lower end fitting firmly together, even through a series of temperature cycles

  11. Chapter 5. Capacitance sensors for use in access tubes

    International Nuclear Information System (INIS)

    Evett, S.; Cepuder, P.

    2008-01-01

    Several manufacturers produce capacitance type sensors for use in plastic access tubes. Some are intended for long term data acquisition with sensors fixed in place, while others are intended to be portable with measurements triggered manually by the user (Fig. 5.1). The common characteristics of this type of sensor include the use of a capacitor consisting of two hollow cylindrical metal electrodes arranged coaxially but separated by several millimetres with an insulating plastic (Fig. 5.2), and the use of an electronic oscillator that produces a sinusoidal waveform. The capacitor forms part of the oscillating circuit, and the electrodes are arranged so as to be very close to the inside of the access tube, the idea being that the fringing field of the capacitor will interact with the soil outside of the tube such that the capacitance is influenced by the soil bulk electrical permittivity and thus by soil water content. In any of these systems, the frequency of oscillation decreases as soil water content increases. Such sensors are also known as frequency domain sensors. All of the sensors in this class are to some extent similar to the early design of Dean and Bell (Dean et al., 1987; Bell et al., 1987). The following discussion will concern systems from three manufacturers: Delta-T, Sentek and Troxler (see Section 1a for manufacturer details). The EnviroSCAN and Diviner 2000 from Sentek are two frequency domain measurement systems based on similar electronics but having very different uses. The Diviner 2000 employs a single capacitance type sensor housed in a cylindrical plastic probe, which is inserted into a plastic access tube and withdrawn in order to obtain 16 readings at depths from 10 to 160 cm in 10 cm increments. The instrument is intended only for manual use. Readings are stored in a datalogger and can later be transferred to a personal computer. The EnviroSCAN uses capacitance sensors of similar design, which are fixed by the user to a plastic

  12. Some Research Experiences in Microwave Tubes 1946 to 1961; From the TWT to the First Laser

    International Nuclear Information System (INIS)

    Birdsall, Charles K.

    2003-01-01

    The period 1946-1961 was a special era for microwave tubes, just after WWII, up until invention of the laser. Low noise, broadband, high power, high efficiency, from 60 MHz to 300 GHz, all done without modern computers (IC's invented in 1959). The major universities and industrial research labs all had active microwave tube research, which was well supported. Beam type tubes of all kinds were invented and experimented with. The Pierce analytic approach became the norm for linear analysis. Time from conception to experiment was short from new guns to new circuits. This paper is one person's experience at three universities and two industrial firms. Challenging, productive and rewarding

  13. How to operate safely steam generators with multiple tube through-wall defects

    International Nuclear Information System (INIS)

    Hernalsteen, P.

    1993-01-01

    For a Nuclear Power Plant (NPP) of the Pressurized Water Reactor (PWR) type, the Steam Generator (SG) tube bundle represents the major but also the thinnest part of the primary pressure boundary. To the extent that no tube material has yet been identified to be immune to corrosion, defects may initiate in service and easily propagate through wall. While not a desirable feature, a Through Wall Deep (TWD) defect does not necessarily pose a threat to either the structural integrity or leaktightness and this paper shows how SG can (and indeed, do) operate safely and reliably while having many tubes affected by deep and even TWD defects

  14. Integrity evaluation for steam generator tube of system integrated modular advanced reactor

    International Nuclear Information System (INIS)

    Kim, J. S.; Jin, T. E.; Jeong, M. J.; Choi, Y. H.; Jeo, J. C.

    2003-01-01

    In this study, the structural integrity for SG tube of system integrated modular advanced reactor, which is subjected to dominant external pressure as well as helical type, is evaluated using the commercial finite element package ABAQUS and the American petrochemical industry code API 579 Appendix B. First of all, the crack behavior under the assumption of local heating is assessed using ABAQUS. And, the buckling behavior of tube with 40% wall thinning is assessed using API 579 Appendix B. As a result, it is found that the crack closure phenomenon occurs under external pressure and the buckling doesn't occur even if 40% wall thinning exists in tube

  15. A Refined Model for Calculation of the Vortex Tube Thermal Characteristics

    Science.gov (United States)

    Biryuk, V. V.; Gorshkalev, A. A.; Uglanov, D. A.; Urlapkin, V. V.; Korneev, S. S.

    2018-01-01

    The article deals with the main types of vortex tubes, provides a brief description of the fundamental principles of the vortex interaction hypothesis. A physical process is represented reflecting the physical essence of the gas flow energetic separation process in the vortex tube due to the intensive turbulent heat exchange from the forced vortex to the free one. A method for refinement of the design characteristics for the cold and hot gas temperatures in a vortex tube through the employment of the gas-dynamic and thermodynamic corrections is proposed. A refined calculation method allows reaching close agreement between the cold gas temperature and the experimental values.

  16. Working session 2: Tubing inspection

    International Nuclear Information System (INIS)

    Guerra, J.; Tapping, R.L.

    1997-01-01

    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

  17. Paramecium swimming in capillary tube

    Science.gov (United States)

    Jana, Saikat; Um, Soong Ho; Jung, Sunghwan

    2012-04-01

    Swimming organisms in their natural habitat need to navigate through a wide range of geometries and chemical environments. Interaction with boundaries in such situations is ubiquitous and can significantly modify the swimming characteristics of the organism when compared to ideal laboratory conditions. We study the different patterns of ciliary locomotion in glass capillaries of varying diameter and characterize the effect of the solid boundaries on the velocities of the organism. Experimental observations show that Paramecium executes helical trajectories that slowly transition to straight lines as the diameter of the capillary tubes decreases. We predict the swimming velocity in capillaries by modeling the system as a confined cylinder propagating longitudinal metachronal waves that create a finite pressure gradient. Comparing with experiments, we find that such pressure gradient considerations are necessary for modeling finite sized ciliary organisms in restrictive geometries.

  18. Atmospheres in a Test Tube

    Science.gov (United States)

    Claudi, R.; Erculiani, M. S.; Giro, E.; D'Alessandro, M.; Galletta, G.

    2013-09-01

    The "Atmosphere in a Test Tube" project is a laboratory experiment that will be able to reproduce condition of extreme environments by means of a simulator. These conditions span from those existing inside some parts of the human body to combinations of temperatures, pressures, irradiation and atmospheric gases present on other planets. In this latter case the experiments to be performed will be useful as preliminary tests for both simulation of atmosphere of exoplanets and Solar System planets and Astrobiology experiments that should be performed by planetary landers or by instruments to be launched in the next years. In particular at INAF Astronomical Observatory of Padova Laboratory we are approaching the characterization of extrasolar planet atmospheres taking advantage by innovative laboratory experiments with a particular focus on low mass Neptunes and Super earths and low mass M dwarfs primaries.

  19. 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

  20. Observation of "YouTube" Language Learning Videos ("YouTube" LLVS)

    Science.gov (United States)

    Alhamami, Munassir

    2013-01-01

    This paper navigates into the "YouTube" website as one of the most usable online tools to learn languages these days. The paper focuses on two issues in creating "YouTube" language learning videos: pedagogy and technology. After observing the existing "YouTube" LLVs, the study presents a novel rubric that is directed…