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Applying a tapered electrode on a porous ceramic support tube by masking a band inside the tube and drawing in electrode material from the outside of the tube by suction
Vasilow, T.R.; Zymboly, G.E.
An electrode is deposited on a support by providing a porous ceramic support tube having an open end and closed end; masking at least one circumferential interior band inside the tube; evacuating air from the tube by an evacuation system, to provide a permeability gradient between the masked part and unmasked part of the tube; applying a liquid dispersion of solid electrode particles to the outside surface of the support tube, where liquid flows through the wall, forming a uniform coating over the unmasked support part and a tapered coating over the masked part. 2 figures.
Multiple tube premixing device
Uhm, Jong Ho; Naidu, Balachandar; Ziminksy, Willy Steve; Kraemer, Gilbert Otto; Yilmaz, Ertan; Lacy, Benjamin; Stevenson, Christian; Felling, David
The present application provides a premixer for a combustor. The premixer may include a fuel plenum with a number of fuel tubes and a burner tube with a number of air tubes. The fuel tubes extend about the air tubes.
Multiple tube premixing device
Uhm, Jong Ho; Varatharajan, Balachandar; Ziminsky, Willy Steve; Kraemer, Gilbert Otto; Yilmaz, Ertan; Lacy, Benjamin; Stevenson, Christian; Felling, David
The present application provides a premixer for a combustor. The premixer may include a fuel plenum with a number of fuel tubes and a burner tube with a number of air tubes. The fuel tubes extend about the air tubes.
Leung, Ka-Ngo (Hercules, CA); Lou, Tak Pui (Berkeley, CA); Reijonen, Jani (Oakland, CA)
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.
Suyama, Motohiro (Hamamatsu, JP); Fukasawa, Atsuhito (Hamamatsu, JP); Arisaka, Katsushi (Los Angeles, CA); Wang, Hanguo (North Hills, CA)
An electron tube of the present invention includes: a vacuum vessel including a face plate portion made of synthetic silica and having a surface on which a photoelectric surface is provided, a stem portion arranged facing the photoelectric surface and made of synthetic silica, and a side tube portion having one end connected to the face plate portion and the other end connected to the stem portion and made of synthetic silica; a projection portion arranged in the vacuum vessel, extending from the stem portion toward the photoelectric surface, and made of synthetic silica; and an electron detector arranged on the projection portion, for detecting electrons from the photoelectric surface, and made of silicon.
Foster, Kenneth G. (Livermore, CA); Frohwein, Eugene J. (San Ramon, CA); Taylor, Robert W. (Livermore, CA); Bowen, David W. (Livermore, CA)
A vermiculite insulated tube furnace is heated by a helically-wound resistance wire positioned within a helical groove on the surface of a ceramic cylinder, that in turn is surroundingly disposed about a doubly slotted stainless steel cylindrical liner. For uniform heating, the pitch of the helix is of shorter length over the two end portions of the ceramic cylinder. The furnace is of large volume, provides uniform temperature, offers an extremely precise programmed heating capability, features very rapid cool-down, and has a modest electrical power requirement.
Tapered pulse tube for pulse tube refrigerators
Swift, Gregory W. (Sante Fe, NM); Olson, Jeffrey R. (San Mateo, CA)
Thermal insulation of the pulse tube in a pulse-tube refrigerator is maintained by optimally varying the radius of the pulse tube to suppress convective heat loss from mass flux streaming in the pulse tube. A simple cone with an optimum taper angle will often provide sufficient improvement. Alternatively, the pulse tube radius r as a function of axial position x can be shaped with r(x) such that streaming is optimally suppressed at each x.
Tube-in-tube thermophotovoltaic generator
Ashcroft, J.; Campbell, B.; DePoy, D.
A thermophotovoltaic device includes at least one thermal radiator tube, a cooling tube concentrically disposed within each thermal radiator tube and an array of thermophotovoltaic cells disposed on the exterior surface of the cooling tube. A shell having a first end and a second end surrounds the thermal radiator tube. Inner and outer tubesheets, each having an aperture corresponding to each cooling tube, are located at each end of the shell. The thermal radiator tube extends within the shell between the inner tubesheets. The cooling tube extends within the shell through the corresponding apertures of the two inner tubesheets to the corresponding apertures of the two outer tubesheets. A plurality of the thermal radiator tubes can be arranged in a staggered or an in-line configuration within the shell. 8 figs.
A tube-in-tube thermophotovoltaic generator
Ashcroft, J.; Campbell, B.; Depoy, D.
A thermophotovoltaic device includes at least one thermal radiator tube, a cooling tube concentrically disposed within each thermal radiator tube and an array of thermophotovoltaic cells disposed on the exterior surface of the cooling tube. A shell having a first end and a second end surrounds the thermal radiator tube. Inner and outer tubesheets, each having an aperture corresponding to each cooling tube, are located at each end of the shell. The thermal radiator tube extends within the shell between the inner tubesheets. The cooling tube extends within the shell through the corresponding apertures of the two inner tubesheets to the corresponding apertures of the two outer tubesheets. A plurality of the thermal radiator tubes can be arranged in a staggered or an in-line configuration within the shell.
Microhole Tubing Bending Report
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Oglesby, Ken
A downhole tubing bending study was made and is reported herein. IT contains a report and 2 excel spreadsheets to calculate tubing bending and to estimate contact points of the tubing to the drilled hole wall (creating a new support point).
Microhole Tubing Bending Report
Oglesby, Ken
A downhole tubing bending study was made and is reported herein. IT contains a report and 2 excel spreadsheets to calculate tubing bending and to estimate contact points of the tubing to the drilled hole wall (creating a new support point).
A Prediction Model for Adiabatic and Diabatic Capillary Tubes with Alternative Refrigerants
Zhang, Yupeng
line) that exits the evaporator, which creates the so called capillary tube/suction line heat exchanger. Models to predict the mass flow in both adiabatic capillary tubes and capillary tube/suction line heat exchangers are developed in this thesis...
Conduction cooled tube supports
Worley, Arthur C. (Mt. Tabor, NJ); Becht, IV, Charles (Morristown, NJ)
In boilers, process tubes are suspended by means of support studs that are in thermal contact with and attached to the metal roof casing of the boiler and the upper bend portions of the process tubes. The support studs are sufficiently short that when the boiler is in use, the support studs are cooled by conduction of heat to the process tubes and the roof casing thereby maintaining the temperature of the stud so that it does not exceed 1400.degree. F.
Crow, W.
This document addresses safety concerns regarding the use of coiled tubing as it pertains to the preservation of personnel, environment and the wellbore.
MacDonald, P.E.; Shah, V.N.; Ward, L.W.; Ellison, P.G.
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.
Broader source: Energy.gov [DOE]
FEMP temporarily suspended its energy efficiency requirements for fluorescent tube lamps as it evaluates the market impact of the pending 2012 minimum efficiency standards for fluorescent lamps. The program will issue updated energy efficiency requirements when the market distribution of this product category stabilizes and when doing so has the potential to result in significant Federal energy savings.
Koppenberger, Peter K.
, and provide two driver sections to allow for dual shock capability. The tube was designed to accommodate a 2.5 MACH shockwave, and incorporated a factor of safety of 3 in the design. A modular approach to design was followed to allow further diversification...
Hull, D.E.
An induction plasma tube having a segmented, fluid-cooled internal radiation shield is disclosed. The individual segments are thick in cross-section such that the shield occupies a substantial fraction of the internal volume of the plasma enclosure, resulting in improved performance and higher sustainable plasma temperatures. The individual segments of the shield are preferably cooled by means of a counterflow fluid cooling system wherein each segment includes a central bore and a fluid supply tube extending into the bore. The counterflow cooling system results in improved cooling of the individual segments and also permits use of relatively larger shield segments which permit improved electromagnetic coupling between the induction coil and a plasma located inside the shield. Four embodiments of the invention, each having particular advantages, are disclosed.
Hull, Donald E. (Los Alamos, NM)
An induction plasma tube having a segmented, fluid-cooled internal radiation shield is disclosed. The individual segments are thick in cross-section such that the shield occupies a substantial fraction of the internal volume of the plasma enclosure, resulting in improved performance and higher sustainable plasma temperatures. The individual segments of the shield are preferably cooled by means of a counterflow fluid cooling system wherein each segment includes a central bore and a fluid supply tube extending into the bore. The counterflow cooling system results in improved cooling of the individual segments and also permits use of relatively larger shield segments which permit improved electromagnetic coupling between the induction coil and a plasma located inside the shield. Four embodiments of the invention, each having particular advantages, are disclosed.
DeJonghe, Lutgard; Jacobson, Craig; Tucker, Michael; Visco, Steven
Tubular objects having two or more concentric layers that have different properties are joined to one another during their manufacture primarily by compressive and friction forces generated by shrinkage during sintering and possibly mechanical interlocking. It is not necessary for the concentric tubes to display adhesive-, chemical- or sinter-bonding to each other in order to achieve a strong bond. This facilitates joining of dissimilar materials, such as ceramics and metals.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for RenewableSpeedingBiomassPPPOPetroleum Reserves Vision,4 Photomultiplier Tube Testing
Concentric tube support assembly
Rubio, Mark F.; Glessner, John C.
An assembly (45) includes a plurality of separate pie-shaped segments (72) forming a disk (70) around a central region (48) for retaining a plurality of tubes (46) in a concentrically spaced apart configuration. Each segment includes a support member (94) radially extending along an upstream face (96) of the segment and a plurality of annularly curved support arms (98) transversely attached to the support member and radially spaced apart from one another away from the central region for receiving respective upstream end portions of the tubes in arc-shaped spaces (100) between the arms. Each segment also includes a radial passageway (102) formed in the support member for receiving a fluid segment portion (106) and a plurality of annular passageways (104) formed in the support arms for receiving respective arm portions (108) of the fluid segment portion from the radial passageway and for conducting the respective arm portions into corresponding annular spaces (47) formed between the tubes retained by the disk.
Bruck, Gerald J.; Bartolomeo, Daniel R.
A reduced-vibration tube array is disclosed. The array includes a plurality of tubes in a fixed arrangement and a plurality of damping members positioned within the tubes. The damping members include contoured interface regions characterized by bracing points that selectively contact the inner surface of an associated tube. Each interface region is sized and shaped in accordance with the associated tube, so that the damping member bracing points are spaced apart a vibration-reducing distance from the associated tube inner surfaces at equilibrium. During operation, mechanical interaction between the bracing points and the tube inner surfaces reduces vibration by a damage-reducing degree. In one embodiment, the interface regions are serpentine shaped. In another embodiment, the interface regions are helical in shape. The interface regions may be simultaneously helical and serpentine in shape. The damping members may be fixed within the associated tubes, and damping member may be customized several interference regions having attributes chosen in accordance with desired flow characteristics and associated tube properties.
Tubing pressurized firing apparatus for a tubing conveyed perforating gun
Davies, D. L.
A tubing pressurized firing apparatus is shown for use with a tubing conveyed perforating gun of the type used to perforate a cased well bore. The firing apparatus has a tubular body with an upper end for connection in the well tubing string and with a lower end for connection to a well perforating gun. An inner mandrel is slidably mounted within the tubular body and has a ball seat formed in the interior bore thereof for receiving a ball dropped through the well tubing string. The ball and ball seat together form a pressure tight seal whereby tubing pressure in the well tubing string acts on the inner mandrel to slide the mandrel downwardly within the tubular body. A cocking mechanism located below the inner mandrel within the body includes a lockout member which is initially positioned between a detonating pin and a percussion detonator. The cocking mechanism is actuated by downward sliding movement of the inner mandrel to move the lockout member from between the detonating pin and percussion detonator whereby a subsequent release of tubing pressure and upward sliding movement of the inner mandrel exposes the detonating pin to the percussion detonator to actuate the detonator and fire the perforating gun.
Method of making straight fuel cell tubes
Borglum, Brian P. (Edgewood, PA)
A method and an apparatus for making straight fuel cell tubes are disclosed. Extruded tubes comprising powders of fuel cell material and a solvent are dried by rotating the extruded tubes. The rotation process provides uniform circumferential drying which results in uniform linear shrinkage of the tubes. The resultant dried tubes are very straight, thereby eliminating subsequent straightening steps required with conventional processes. The method is particularly useful for forming inner air electrode tubes of solid oxide fuel cells.
Korneev, Valeri A. (Lafayette, CA); Bakulin, Andrey (Houston, TX)
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.
Korneev, Valeri A [LaFayette, CA
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.
Steam generator tube rupture study
Free, Scott Thomas
This report describes our investigation of steam generator behavior during a postulated tube rupture accident. Our study was performed using the steam generator, thermal-hydraulic analysis code THERMIT-UTSG. The purpose ...
Opposed slant tube diabatic sorber
Erickson, Donald C.
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.
Apparatus for connecting aligned abutted tubes
Williams, R.E.
An apparatus for connecting abutted tubes and for maintaining their rotary alignment during connection. The apparatus comprises first and second tubes, a rotation prevention element, a collar and a retainer. Each tube has inside and outside walls, and first and second ends, each end having an inside and outside edge. The first tube has portions defining a first plurality of cavities located at the outside edge of its first end. An external threaded portion is on the outside wall of the first tube and next to the first plurality of cavities. The second tube has portions defining a second plurality of cavities located at the outside edge of its first end. The first plurality has a different number than the second plurality. The first ends of the first and second tubes have substantially the same outside diameter and are abutted during connection so that an orifice is formed whenever first and second tube cavities substantially overlap. A rotation prevension element is placed in the orifice to prevent rotation of the first and second tubes. A collar with an internal threaded portion is slidably disposed about the second tube. The internal threaded portion engages the external threaded portion of the first tube to connect the tubes. A lip connected to the collar prevents separation of the collar from the second tube.
Fracture compliance estimation using borehole tube waves
Bakku, Sudhish Kumar
We tested two models, one for tube-wave generation and the other for tube-wave attenuation at a fracture intersecting a borehole that can be used to estimate fracture compliance, fracture aperture, and lateral extent. In ...
Two phase flow in capillary tubes
Suo, Mikio
The flow of two phases, gas and liquid, has been studied in horizontal tubes of capillary diameter. The flow has been primarily studied in the regime where the gas flows as long bubbles separated from the wall of the tube ...
Performance of drift tubes under high radiation
Shi, Yue, S.B. Massachusetts Institute of Technology
In this thesis, the aging and the rejuvenation of an ATLAS proportional drift tube are described. Firstly, the Diethorn model of gain is tested using pressure and sense-wire voltage measurements. The drift tube was then ...
Stability of tube rows in crossflow. [LMFBR
Chen, S.S.; Jendrzejczyk, J.A.
A mathematical model for the instability of tube rows subjected to crossflow is examined. The theoretical model, based on the fluid-force data for a pitch-to-diameter ratio of 1.33, provides additional insight into the instability phenomenon. Tests are also conducted for three sets of tube rows. The effects of mass ratio, tube pitch, damping, detuning and finned tubes are investigated. Theoretical results and experimental data are in good agreement.
Spring/dimple instrument tube restraint
DeMario, E.E.; Lawson, C.N.
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.
Manual tube-to-tubesheet welding torch
Kiefer, Joseph H. (Tampa, FL); Smith, Danny J. (Tampa, FL)
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.
Studies of Degraded Smelt Spout Opening Tubes
Keiser, James R [ORNL; Kish, Joseph R. [Paprican; Willoughby, Adam W [ORNL; Longmire, Hu Foster [ORNL; Singbeil, Douglas [Paprican
Co-extruded type 304L stainless steel/SA210 carbon steel tubes have been used on the floors and lower walls of many black liquor recovery boilers to address the wall thinning problem that had been an issue for boiler owners and operators. Use of these tubes greatly reduced the corrosion issue, but corrosion was still sometimes observed and cracking was discovered in some tubes, particularly those that are bent to form the openings for smelt spouts. Because cracks in the opening tubes were sometimes observed to extend a significant distance into the tube wall and because these cracks were found fairly frequently, tubes made from a number of alternate cladding materials were tried in place of the 304L clad opening tubes. This paper describes the results of examinations of spout opening tubes of the standard 304L/carbon steel and of several of the alternate materials that have been tried. In addition to the corrosion and cracking seen in the spout opening tubes, another issue associated with these tubes has been observed. Preferential corrosion of the cap welds is sometimes seen on butt welds attaching the spout opening tubes made with alternate cladding materials to the standard 304L/carbon steel co-extruded wall tubes. Some information on the observations of this corrosion is also included in this paper.
Tubing carried perforating gun with insulation jacket
Donovan, J.F.; Yates, D.N.
This patent describes a method of insulating a tubing carried perforating gun which is run through a subterranean wellbore. It includes making up at the well surface a tubing string for introduction within the well, the tubing string carrying a perforating gun assembly.
Ionization tube simmer current circuit
Steinkraus, Jr., Robert F. (Livermore, CA)
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.
Ionization tube simmer current circuit
Steinkraus, R.F. Jr.
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.
Cold cathode vacuum discharge tube
Boettcher, Gordon E. (Albuquerque, NM)
A cold cathode vacuum discharge tube, and method for making same, with an interior surface of the trigger probe coated with carbon deposited by carbon vapor deposition (CVD) or diamond-like carbon (DLC) deposition. Preferably a solid graphite insert is employed in the probe-cathode structure in place of an aluminum bushing employed in the prior art. The CVD or DLC probe face is laser scribed to allow resistance trimming to match available trigger voltage signals and to reduce electrical aging.
Fluidized bed boiler convective zone tube replacement
Not Available
A major problem with the Georgetown University Atomspheric-Pressure, Fluidized-Bed Combustor-Boiler (GU AFBC) experienced during the first six years of operation was tube erosion. Previous corrective measures for in-bed tube erosion appeared to be effective, but excessive wear of the convective zone tubes was still occurring, and the entire heat transfer tube bundle in the boiler required replacement. In the planned project,the eroded tubes would be replaced, and the convective zone modified to eliminate the problem. Progress is discussed.
Turbine nozzle stage having thermocouple guide tube
Schotsch, Margaret Jones (Greer, SC); Kirkpatrick, Francis Lawrence (late of Galway, NY); Lapine, Eric Michael (Northwood, NH)
A guide tube is fixed adjacent opposite ends in outer and inner covers of a nozzle stage segment. The guide tube is serpentine in shape between the outer and inner covers and extends through a nozzle vane. An insert is disposed in the nozzle vane and has apertures to accommodate serpentine portions of the guide tube. Cooling steam is also supplied through chambers of the insert on opposite sides of a central insert chamber containing the guide tube. The opposite ends of the guide tube are fixed to sleeves, in turn fixed to the outer and inner covers.
Multi-tube arrangement for combustor and method of making the multi-tube arrangement
Ziminsky, Willy Steve (Simpsonville, SC)
A fuel injector tube includes a one piece, unitary, polygonal tube having an inlet end and an outlet end. The fuel injector tube further includes a fuel passage extending from the inlet end to the outlet end along a longitudinal axis of the polygonal tube, a plurality of air passages extending from the inlet end to the outlet end and surrounding the fuel passage, and a plurality of fuel holes. Each fuel hole connects an air passage with the fuel passage. The inlet end of the polygonal tube is formed into a fuel tube. A fuel injector includes a plurality of fuel injector tubes and a plate. The plurality of fuel tubes are connected to the plate adjacent the inlet ends of the plurality of fuel injector tubes.
Cold cathode vacuum discharge tube
Boettcher, G.E.
A cold cathode vacuum discharge tube, and method for making same, with an interior surface of the trigger probe coated with carbon deposited by chemical vapor deposition (CVD) or diamond-like carbon (DLC) deposition are disclosed. Preferably a solid graphite insert is employed in the probe-cathode structure in place of an aluminum bushing employed in the prior art. The CVD or DLC probe face is laser scribed to allow resistance trimming to match available trigger voltage signals and to reduce electrical aging. 14 figs.
Cold cathode vacuum discharge tube
Boettcher, G.E.
A cold cathode vacuum discharge tube, and method for making same, are disclosed with an interior surface of the trigger probe coated with carbon deposited by carbon vapor deposition (CVD) or diamond-like carbon (DLC) deposition. Preferably a solid graphite insert is employed in the probe-cathode structure in place of an aluminum bushing employed in the prior art. The CVD or DLC probe face is laser scribed to allow resistance trimming to match available trigger voltage signals and to reduce electrical aging. 15 figs.
Large Diameter Lasing Tube Cooling Arrangement
Hall, Jerome P.; Alger, Terry W.; Anderson, Andrew T.; Arnold, Philip A.
A cooling structure (16) for use inside a ceramic cylindrical tube (11) of a metal vapor laser (10) to cool the plasma in the tube (11), the cooling structure (16) comprising a plurality of circular metal members (17,31) and mounting members (18, 34) that position the metal members (17,31) coaxially in the tube (11) to form an annular lasing volume, with the metal members (17, 31) being axially spaced from each other along the length of the tube (11) to prevent the metal members from shorting out the current flow through the plasma in the tube (11) and to provide spaces through which the heat from localized hot spots in the plasma may radiate to the other side of the tube (11).
Large diameter lasing tube cooling arrangement
Hall, Jerome P. (Livermore, CA); Alger, Terry W. (Tracy, CA); Anderson, Andrew T. (Livermore, CA); Arnold, Phillip A. (Livermore, CA)
A cooling structure (16) for use inside a ceramic cylindrical tube (11) of a metal vapor laser (10) to cool the plasma in the tube (11), the cooling structure (16) comprising a plurality of circular metal members (17, 31) and mounting members (18, 34) that position the metal members (17, 31) coaxially in the tube (11) to form an annular lasing volume, with the metal members (17, 31) being axially spaced from each other along the length of the tube (11) to prevent the metal members from shorting out the current flow through the plasma in the tube (11) and to provide spaces through which the heat from localized hot spots in the plasma may radiate to the other side of the tube (11).
Tube support grid and spacer therefor
Ringsmuth, Richard J. (Solano Beach, CA); Kaufman, Jay S. (Del Mar, CA)
A tube support grid and spacers therefor provide radially inward preloading of heat exchange tubes to minimize stress upon base welds due to differential thermal expansion. The grid comprises a concentric series of rings and spacers with opposing concave sides for conforming to the tubes and V-shaped ends to provide resilient flexibility. The flexibility aids in assembly and in transmitting seismic vibrations from the tubes to a shroud. The tube support grid may be assembled in place to achieve the desired inwardly radial preloading of the heat exchange tubes. Tab and slot assembly further minimizes stresses in the system. The radii of the grid rings may be preselected to effect the desired radially inward preloading.
Eddy current measurement of tube element spacing
Latham, Wayne Meredith (Forest, VA); Hancock, Jimmy Wade (Lynchburg, VA); Grut, Jayne Marie (Madison Heights, VA)
A method of electromagnetically measuring the distance between adjacent tube elements in a heat exchanger. A cylindrical, high magnetic permeability ferrite slug is placed in the tube adjacent the spacing to be measured. A bobbin or annular coil type probe operated in the absolute mode is inserted into a second tube adjacent the spacing to be measured. From prior calibrations on the response of the eddy current coil, the signals from the coil, when sensing the presence of the ferrite slug, are used to determine the spacing between the tubes.
Pool boiling of R-114/oil mixtures from single tubes and tube bundles. Master's thesis
Murphy, T.J.
An apparatus was designed, fabricated, and operated for the testing of horizontal tube bundles for boiling of R-114 with various concentrations of oil. Preliminary data were taken on the top tube in the bundle, with and without the other tubes in operation. Results showed up to a 37% increase in the boiling heat-transfer coefficient as a result of the favorable bundle effect. In a separate single-tube apparatus, three enhanced tubes were tested at a saturation temperature of 2.2 C with oil mass concentrations of 0, 1, 2, 3, 6 and 10%. The tubes were: 1) a finned tube with 1024 fins per meter, 2) a finned tube with 1575 fins per meter and 3) a Turbo-B tube. These tubes resulted in enhancement ratios in pure refrigerant of 2.8, 3.8 and 5.2, respectively, at a practical heat flux of 30 kW/sq. meter. With 3% oil, these ratios were decreased to 2.6, 3.5 and 5, while with 10% oil, these ratios were further reduced to 2.6, 3.2 and 4.7, respectively. Based on these results, the use of Turbo-B tubes is expected to result in significant savings in weight and size of evaporators over the finned tubes presently in use on board some naval vessels.
Sampling Artifacts from Conductive Silicone Tubing
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.
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.
Horizontal Beam Tubes - HFIR Technical Parameters | ORNL Neutron...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Beam Tubes The reactor has four horizontal beam tubes that supply the neutrons to the neutron scattering instruments. Details for each beam tube and instrument can be found on...
Photomultiplier Tubes: Calibration and Neutrino Physics
Damon, Edward; Maricic, Jelena [Drexel University, Philadelphia, PA 19104 (United States)
Photomultiplier Tubes are devices designed to amplify very small light signals, on the order of single photons, to levels that are detectable by conventional electronics. Such a high level of amplification, however, comes with a quite a few potential problems, as the relationship between a light signal in and the current out- the response of the system- can be difficult to determine, meaning that photomultiplier tubes' use in scientific research requires a great deal of sensitive calibration. Once calibrated, the photomultiplier tube is a tool that can be used on a number of interesting problems, including the field of neutrino physics. This work deals with the use of photomultiplier tubes' use in the upcoming Double Chooz experiment to determine the mixing angle theta{sub 13}, between different neutrino mass eigenstates. Calibration of the tubes requires measurement of the charge characteristics, most notably, the gain, pedestal, and the dark rate of a tube. Moreover, for all modern tubes, there is an additional feature which can be used to calibrate the system, the single photo electron peak, which describes the response of the tube to a single photon. Some theories predict higher order effects, in addition to the single photoelectron peak, including things like incomplete multiplication of a single photon electron, features which are theoretically able to be determined by a detailed examination of the single photoelectron peak. This paper goes through the methods of calibrating a phototubes both with and without a single photoelectron peak, and is unable to determine conclusively whether or not partial multiplication is able to explain certain features of photomultiplier tubes with a single photoelectron peak.
Multi-tube fuel nozzle with mixing features
Hughes, Michael John
A system includes a multi-tube fuel nozzle having an inlet plate and a plurality of tubes adjacent the inlet plate. The inlet plate includes a plurality of apertures, and each aperture includes an inlet feature. Each tube of the plurality of tubes is coupled to an aperture of the plurality of apertures. The multi-tube fuel nozzle includes a differential configuration of inlet features among the plurality of tubes.
Scintillation probe with photomultiplier tube saturation indicator
Ruch, Jeffrey F. (Bethel Park, PA); Urban, David J. (Glassport, PA)
A photomultiplier tube saturation indicator is formed by supplying a supplemental light source, typically an light emitting diode (LED), adjacent to the photomultiplier tube. A switch allows the light source to be activated. The light is forwarded to the photomultiplier tube by an optical fiber. If the probe is properly light tight, then a meter attached to the indicator will register the light from the LED. If the probe is no longer light tight, and the saturation indicator is saturated, no signal will be registered when the LED is activated.
Resonant absorption in dissipative flux tubes
Safari, H; Karami, K; Sobouti, Y
Oscillations of coronal loops are believed to be the primary cause of the solar corona heating. We study the resonant absorbtion of MHD waves in magnetized flux tubes with graded densities across the cross section of the tube. Within the approximation that resistive and viscous processes are operative in thin layers surrounding the singularities of the MHD equations, we give the full spectrum of the eigenfrequencies, damping rates, as well as, the eigenfields of the normal MHD modes of the tube. Both surface and body modes are analyzed and the contribution of each class to heating of the corona is commented on.
Hydrogen Tube Trailers | Department of Energy
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AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page onYouTube YouTube Note: Since the.pdfBreaking of Blythe SolarContaminationCurrent Technology »Clean CoalTube Trailers
Alternative Electrostatic Green's Function for a Long Tube. ...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Alternative Electrostatic Green's Function for a Long Tube. Alternative Electrostatic Green's Function for a Long Tube. Abstract: This note describes an expression for the...
Electric and Gas Fired Radiant Tubes 'ERT'
Nilsen, E. K.
The paper covers a unique development by the Surface Division of Midland Ross of a radiant tube heating element which will heat an industrial furnace with either gas or electric without any down time or physical conversion required...
Electric and Gas Fired Radiant Tubes 'ERT'�
Nilsen, E. K.
The paper covers a unique development by the Surface Division of Midland Ross of a radiant tube heating element which will heat an industrial furnace with either gas or electric without any down time or physical conversion required...
Staged multi-tube premixing injector
Zuo, Baifang; Khan, Abdul Rafey; York, William David; Ziminsky, Willy Steve
A fuel injection nozzle includes a body member having an upstream wall opposing a downstream wall, and an internal wall disposed between the upstream wall and the downstream wall, a first chamber partially defined by the an inner surface of the upstream wall and a surface of the internal wall, a second chamber partially defined by an inner surface of the downstream wall and a surface of the internal wall a first gas inlet communicative with the first chamber operative to emit a first gas into the first chamber, a second gas inlet communicative with the second chamber operative to emit a second gas into the second chamber, and a plurality of mixing tubes, each of the mixing tubes having a tube inner surface, a tube outer surface, a first inlet communicative with an aperture in the upstream wall operative to receive a third gas.
Forced-convection condensation inside tubes
Traviss, Donald P.
High vapor velocity condensation inside a tube was studied analytically. The von Karman universal velocity distribution was applied to the condensate flow, pressure drops were calculated using the Lockhart- Martinelli ...
Fluidized bed combustor and tube construction therefor
De Feo, Angelo (Passaic, NJ); Hosek, William (Morris, NJ)
A fluidized bed combustor comprises a reactor or a housing which has a windbox distributor plate adjacent the lower end thereof which contains a multiplicity of hole and air discharge nozzles for discharging air and coal into a fluidized bed which is maintained above the distributor plate and below a take-off connection or flue to a cyclone separator in which some of the products of combustion are treated to remove the dust which is returned into the fluidized bed. A windbox is spaced below the fluidized bed and it has a plurality of tubes passing therethrough with the passage of combustion air and fluidizing air which passes through an air space so that fluidizing air is discharged into the reaction chamber fluidized bed at the bottom thereof to maintain the bed in a fluidized condition. A fluid, such as air, is passed through the tubes which extend through the windbox and provide a preheating of the combustion air and into an annular space between telescoped inner and outer tubes which comprise heat exchanger tubes or cooling tubes which extend upwardly through the distributor plate into the fluidized bed. The heat exchanger tubes are advantageously arranged so that they may be exposed in groups within the reactor in a cluster which is arranged within holding rings.
Tube construction for fluidized bed combustor
De Feo, Angelo (Totowa, NJ); Hosek, William (Mt. Tabor, NJ)
A fluidized bed combustor comprises a reactor or a housing which has a windbox distributor plate adjacent the lower end thereof which contains a multiplicity of hole and air discharge nozzles for discharging air and coal into a fluidized bed which is maintained above the distributor plate and below a take-off connection or flue to a cyclone separator in which some of the products of combustion are treated to remove the dust which is returned into the fluidized bed. A windbox is spaced below the fluidized bed and it has a plurality of tubes passing therethrough with the passage of combustion air and fluidizing air which passes through an air space so that fluidizing air is discharged into the reaction chamber fluidized bed at the bottom thereof to maintain the bed in a fluidized condition. A fluid, such as air, is passed through the tubes which extend through the windbox and provide a preheating of the combustion air and into an annular space between telescoped inner and outer tubes which comprise heat exchanger tubes or cooling tubes which extend upwardly through the distributor plate into the fluidized bed. The heat exchanger tubes are advantageously arranged so that they may be exposed in groups within the reactor in a cluster which is arranged within holding rings.
Suction muffler for refrigeration compressor
Nelson, R.T.; Middleton, M.G.
A hermetic refrigeration compressor includes a suction muffler formed from two pieces of plastic material mounted on the cylinder housing. One piece is cylindrical in shape with an end wall having an aperture for receiving a suction tube connected to the cylinder head. The other piece fits over and covers the other end of the cylindrical piece, and includes a flaring entrance horn which extends toward the return line on the sidewall of the compressor shell. 5 figs.
Suction muffler for refrigeration compressor
Nelson, Richard T. (Worthington, OH); Middleton, Marc G. (West Jefferson, OH)
A hermetic refrigeration compressor includes a suction muffler formed from two pieces of plastic material mounted on the cylinder housing. One piece is cylindrical in shape with an end wall having an aperture for receiving a suction tube connected to the cylinder head. The other piece fits over and covers the other end of the cylindrical piece, and includes a flaring entrance horn which extends toward the return line on the sidewall of the compressor shell.
Automated Diagnosis and Classification of Steam Generator Tube Defects
Dr. Gabe V. Garcia
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.
Design and evaluate finned tube bundles
Ganapathy, V. [ABCO Industries, Abilene, TX (United States)
Finned tube bundles are widely used in heat exchangers, air coolers, waste heat boilers and fired heaters where energy transfer occurs between clean flue gases and a fluid with a high heat-transfer coefficient. They have several advantages including compactness, low gas pressure drop and low weight for a given duty compared to bare tube bundles. Choosing a fin type, arrangement and fin configuration requires a thorough analysis and economic evaluation. The solution is not unique since it depends on material and labor costs. Surface areas vary widely in finned tube designs for the same duty and gas pressure drop. Therefore, decisions should not be based on surface area alone. Plant engineers and consultants should consider operating costs in their evaluation because they accrue year after year. Selecting a boiler based on initial costs alone is not prudent. The paper discusses heat transfer and gas pressure drop with finned tubes, determining fin efficiency and effectiveness,g as pressure drop, tube wall and fin top temperatures, an example calculation, the effect of fin configuration on design, the effect of inline versus staggered arrangements and solid versus serrated fins, and concerns with high fin-density designs.
Alternate Materials for Recovery Boiler Superheater Tubes
Keiser, James R [ORNL; Kish, Joseph [McMaster University; Singbeil, Douglas [FPInnovations
The ever escalating demands for increased efficiency of all types of boilers would most sensibly be realized by an increase in the steam parameters of temperature and pressure. However, materials and corrosion limitations in the steam generating components, particularly the superheater tubes, present major obstacles to boiler designers in achieving systems that can operate under the more severe conditions. This paper will address the issues associated with superheater tube selection for many types of boilers; particularly chemical recovery boilers, but also addressing the similarities in issues for biomass and coal fired boilers. It will also review our recent study of materials for recovery boiler superheaters. Additional, more extensive studies, both laboratory and field, are needed to gain a better understanding of the variables that affect superheater tube corrosion and to better determine the best means to control this corrosion to ultimately permit operation of recovery boilers at higher temperatures and pressures.
Circumferential cracking of steam generator tubes
Karwoski, K.J.
On April 28, 1995, the U.S. Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 95-03, {open_quote}Circumferential Cracking of Steam Generator Tubes.{close_quote} GL 95-03 was issued to obtain information needed to verify licensee compliance with existing regulatory requirements regarding the integrity of steam generator tubes in domestic pressurized-water reactors (PWRs). This report briefly describes the design and function of domestic steam generators and summarizes the staff`s assessment of the responses to GL 95-03. The report concludes with several observations related to steam generator operating experience. This report is intended to be representative of significant operating experience pertaining to circumferential cracking of steam generator tubes from April 1995 through December 1996. Operating experience prior to April 1995 is discussed throughout the report, as necessary, for completeness.
Zero dead volume tube to surface seal
Benett, William J. (Livermore, CA); Folta, James A. (Livermore, CA)
A method and apparatus for connecting a tube to a surface that creates a dead volume seal. The apparatus is composed of three components, a body, a ferrule, and a threaded fitting. The ferrule is compressed onto a tube and a seal is formed between the tube and a device retained in the body by threading the fitting into the body which provides pressure that seals the face of the ferrule to a mating surface on the device. This seal can be used at elevated temperatures depending on the materials used. While the invention has been developed for use with micro-machined silicon wafers used in Capillary Gas Chromatograph (GC), it can be utilized anywhere for making a gas or fluid face seal to the surface of a device that has near zero dead volume.
Pulse tube coolers for Meteosat third generation
Butterworth, James; Aigouy, G�rald; Chassaing, Clement; Debray, Beno�t; Huguet, Alexandre [Air Liquide Advanced Technologies, 2 Rue de Cl�menci�re, F-38600 Sassenage (France)
Air Liquide's Large Pulse Tube Coolers (LPTC) will be used to cool the focal planes of the Infrared Sounder (IRS) and Flexible Combined Imager (FCI) instruments aboard the ESA/Eumetsat satellites Meteosat Third Generation (MTG). This cooler consists of an opposed piston linear compressor driving a pulse tube cold head and the associated drive electronics including temperature regulation and vibration cancellation algorithms. Preparations for flight qualification of the cooler are now underway. In this paper we present results of the optimization and qualification activities as well as an update on endurance testing.
A Flexural Mode Tuning Technique for Membraned Boiler Tubing
Quarry, M J; Chinn, D J; Rose, J L
Corrosion of tubing used in black-liquor recovery boilers is a major concern in all pulp and paper mills. Extensive corrosion in recovery boiler tubes can result in a significant safety and environmental hazard. Considerable plant resources are expended to inspect recovery boiler tubing. Currently, visual and ultrasonic inspections are primarily used during the annual maintenance shutdown to monitor corrosion rates and cracking of tubing. This project is developing guided acoustic waves for use on recovery boiler tubing. The feature of this acoustic technique is its cost-effectiveness in inspecting long lengths of tubes from a single inspection point. A piezoelectric or electromagnetic transducer induces guided waves into the tubes. The transducer detects fireside defects from the cold side or fireside of the tube. Cracking and thinning on recovery boiler tubes have been detected with this technique in both laboratory and field applications.
Digital radiographic systems detect boiler tube cracks
Walker, S. [EPRI, Charlotte, NC (United States)
Boiler water wall leaks have been a major cause of steam plant forced outages. But conventional nondestructive evaluation techniques have a poor track record of detecting corrosion fatigue cracking on the inside surface of the cold side of waterwall tubing. EPRI is performing field trials of a prototype direct-digital radiographic system that promises to be a game changer. 8 figs.
Wave guides: vacuum w/ tube of conductor
Hart, Gus
Wave guides: vacuum w/ tube of conductor boundary conditions for conductor Properties: non-transverse waves except TEM mode in coaxial cable speed normal modes (from Liouville problem) TE or TM TEM for coaxial cable cuto frequency otherwise evanescent waves separation into and components with 1 #12;B
Stress-Assisted Corrosion in Boiler Tubes
Preet M Singh; Steven J Pawel
A number of industrial boilers, including in the pulp and paper industry, needed to replace their lower furnace tubes or decommission many recovery boilers due to stress-assisted corrosion (SAC) on the waterside of boiler tubes. More than half of the power and recovery boilers that have been inspected reveal SAC damage, which portends significant energy and economic impacts. The goal of this project was to clarify the mechanism of stress-assisted corrosion (SAC) of boiler tubes for the purpose of determining key parameters in its mitigation and control. To accomplish this in-situ strain measurements on boiler tubes were made. Boiler water environment was simulated in the laboratory and effects of water chemistry on SAC initiation and growth were evaluated in terms of industrial operations. Results from this project have shown that the dissolved oxygen is single most important factor in SAC initiation on carbon steel samples. Control of dissolved oxygen can be used to mitigate SAC in industrial boilers. Results have also shown that sharp corrosion fatigue and bulbous SAC cracks have similar mechanism but the morphology is different due to availability of oxygen during boiler shutdown conditions. Results are described in the final technical report.
Composite Tube Trailer Design/Manufacturing Needs
composite tube trailers and can, therefore, address issues with: Design Materials Manufacturing in the system Lower cost of carbon fiber ($/strength) Identify material with lower net cost ($/strength) Identify lower cost resin system (raw material & manufacture) Reduce carbon fiber safety factor
Energies of Quantum QED Flux Tubes
H Weigel
In this talk I present recent studies on vacuum polarization energies and energy densities induced by QED flux tubes. I focus on comparing three and four dimensional scenarios and the discussion of various approximation schemes in view of the exact treatment.
Flux tubes in the SU(3) vacuum
Mario S. Cardaci; Paolo Cea; Leonardo Cosmai; Rossella Falcone; Alessandro Papa
We analyze the distribution of the chromoelectric field generated by a static quark-antiquark pair in the SU(3) vacuum. We find that the transverse profile of the flux tube resembles the dual version of the Abrikosov vortex field distribution and give an estimate of the London penetration length in the confined vacuum.
"Fine grain Nb tube for SRF cavities"
Robert E. Barber
Superconducting radio frequency (SRF) cavities used in charged particle linear accelerators, are currently fabricated by deep drawing niobium sheets and welding the drawn dishes together. The Nb sheet has a non-uniform microstructure, which leads to unpredictable cavity shape and surface roughness, and inconsistent "spring-back" during forming. In addition, weld zones cause hot spots during cavity operation. These factors limit linear accelerator performance and increase cavity manufacturing cost. Equal channel angular extrusion (ECAE) can be used to refine and homogenize the microstructure of Nb tube for subsequent hydroforming into SRF cavities. Careful selection of deformation and heat treatment conditions during the processing steps can give a uniform and consistent microstructure in the tube, leading to improved deformability and lower manufacturing costs. Favorable microstructures were achieved in short test samples of RRR Nb tube, which may be particularly suitable for hydroforming into SRF cavity strings. The approach demonstrated could be applicable to microstructure engineering of other tube materials including tantalum, titanium, and zirconium.
Math 13900 YouTube Quiz 2013 Find a video on YouTube that ...
Roames, Renee S
Find a video on YouTube that addresses the idea of symmetry � either for 2 dimensions or 3 as we have been studying in lessons 9 and 10. The video should be�...
Insulated laser tube structure and method of making same
Dittbenner, Gerald R. (4353 Findlay Way, Livermore, CA 94550)
An insulated high temperature ceramic laser tube having substantially uniform insulation along the length of the tube is disclosed having particulate ceramic insulation positioned between the outer wall of the ceramic laser tube and the inner surface of tubular ceramic fiber insulation which surrounds the ceramic laser tube. The particulate ceramic insulation is preferably a ceramic capable of sintering to the outer surface of the ceramic laser tube and to the inner surface of the tubular ceramic fiber insulation. The addition of the particulate ceramic insulation to fill all the voids between the ceramic laser tube and the fibrous ceramic insulation permits the laser tube to be operated at a substantially uniform temperature throughout the length of the laser tube.
Refrigerant forced-convection condensation inside horizontal tubes
Bae, Soonhoon
Condensing heat transfer rates inside a horizontal tube were investigated -for large quality changes across the tube. The proposed correlation is a modification of the work of Rohsenow, Webber and Ling [29]. The result of ...
Fouling of HVAC fin and tube heat exchangers
Siegel, Jeffrey; Carey, Van P.
air ? air ? part ? part FPI HVAC REFERENCES Anonymous, 1987,LBNL-47668 Fouling of HVAC Fin and Tube Heat ExchangersCIEE SPONSOR. FOULING OF HVAC FIN AND TUBE HEAT EXCHANGERS
Nonlinear axisymmetric deformations of an elastic tube under external pressure
Luo, Xiaoyu
tube subject to pressure on its external lateral boundaries and zero displacement on its ends) performed a numerical simulation of the post-buckling behaviour of tubes under external pressure
Heat transfer of finned tube bundles in crossflow
Stasiulevicius, J.; Skrinska, A.; Zukauskas, A.
This volume correlates findings on heat transfer and hydraulic drag of bundles of finned tubes in crossflow at Reynolds numbers from 10/sup 4/ to 10/sup 6/. These studies illustrate fin, local, and mean heat transfer coefficients; effects of geometric parameters of the fins; effect of tube location within the bundle on heat transfer and hydraulic drag; and resistance of finned tube bundles.
Iterative Learning Control Applications to High Power Microwave Tubes
day high-peak power microwave (HPM) sources typically operate in the * *single shot regime because commercial HPM systems that operate at modest repetition rates, two examples of* * which include a system the control algorithms on a * *physical tube in order to build a "smart tube" HPM source. By smart tube we
Investigation of pressure-tube and calandria-tube deformation following a single channel blockage event in ACR-700
Gerardi, Craig Douglas
The ACR-700 is an advanced pressure-tube (PT) reactor being developed by Atomic Energy of Canada Limited (AECL). As in conventional CANDU reactors, the PTs are horizontal. Each PT is surrounded by a calandria tube (CT), ...
Investigation of Pressure-Tube and Calandria-Tube Deformation Following a Single Channel Blockage Event in ACR-700
Gerardi, C.
The ACR-700 is an advanced pressure-tube (PT) reactor being developed by Atomic Energy of Canada Limited (AECL). As in conventional CANDU reactors, the PTs are horizontal. Each PT is surrounded by a calandria tube (CT), ...
Sheared bioconvection in a horizontal tube
Croze, O A; Bees, M A; 10.1088/1478-3975/7/4/046001
The recent interest in using microorganisms for biofuels is motivation enough to study bioconvection and cell dispersion in tubes subject to imposed flow. To optimize light and nutrient uptake, many microorganisms swim in directions biased by environmental cues (e.g. phototaxis in algae and chemotaxis in bacteria). Such taxes inevitably lead to accumulations of cells, which, as many microorganisms have a density different to the fluid, can induce hydrodynamic instabilites. The large-scale fluid flow and spectacular patterns that arise are termed bioconvection. However, the extent to which bioconvection is affected or suppressed by an imposed fluid flow, and how bioconvection influences the mean flow profile and cell transport are open questions. This experimental study is the first to address these issues by quantifying the patterns due to suspensions of the gravitactic and gyrotactic green biflagellate alga Chlamydomonas in horizontal tubes subject to an imposed flow. With no flow, the dependence of the domi...
Laced permanent magnet quadrupole drift tube magnets
Feinberg, B.; Behrsing, G.U.; Halbach, K.; Marks, J.S.; Morrison, M.E.; Nelson, D.H.
Twenty-three laced permanent magnet quadrupole drift tube magnets have been constructed, tested, and installed in the SuperHILAC heavy ion linear accelerator at LBL, marking the first accelerator use of this new type of quadrupole. The magnets consist of conventional tape-wound quadrupole electromagnets, using iron pole-pieces, with permanent magnet material (samarium cobalt) inserted between the poles to reduce the effects of saturation. The iron is preloaded with magnetic flux generated by the permanent magnet material, resulting in an asymmetrical saturation curve. Since the polarity of the individual quadrupole magnets in a drift tube linac is never reversed, we can take advantage of this asymmetrical saturation to provide about 20% greater focusing strength than is available with conventional quadrupoles, while replacing the vanadium permendur poletips with iron poletips. Comparisons between these magnets and conventional tape-wound quadrupoles will be presented. 3 refs., 5 figs.
Fission of a multiphase membrane tube
Jean-Marc Allain; Cornelis Storm; Aurelien Roux; Martine Ben Amar; Jean-Francois Joanny
A common mechanism for intracellular transport is the use of controlled deformations of the membrane to create spherical or tubular buds. While the basic physical properties of homogeneous membranes are relatively well-known, the effects of inhomogeneities within membranes are very much an active field of study. Membrane domains enriched in certain lipids in particular are attracting much attention, and in this Letter we investigate the effect of such domains on the shape and fate of membrane tubes. Recent experiments have demonstrated that forced lipid phase separation can trigger tube fission, and we demonstrate how this can be understood purely from the difference in elastic constants between the domains. Moreover, the proposed model predicts timescales for fission that agree well with experimental findings.
Ion sources for sealed neutron tubes
Burns, E.J.T. [Sandia National Labs., Albuquerque, NM (United States). Neutron Tube Dept.; Bischoff, G.C. [Lockheed Martin Specialty Components, Largo, FL (United States)
Fast and thermal neutron activation analysis with sealed neutron generators has been used to detect oil (oil logging), hazardous waste, fissile material, explosives, and contraband (drugs). Sealed neutron generators, used in the above applications, must be small and portable, have good electrical efficiency and long life. The ion sources used in the sealed neutron tubes require high gas utilization efficiencies or low pressure operation with high ionization efficiencies. In this paper, the authors compare a number of gas ion sources that can be used in sealed neutron tubes. The characteristics of the most popular ion source, the axial Penning discharge will be discussed as part of the zetatron neutron generator. Other sources to be discussed include the SAMIS source and RF ion source.
Coupled-cavity drift-tube linac
Billen, J.H.
A coupled-cavity drift-tube linac (CCDTL) combines features of the Alvarez drift-tube linac (DTL) and the {pi}-mode coupled-cavity linac (CCL). In one embodiment, each accelerating cavity is a two-cell, 0-mode DTL. The center-to-center distance between accelerating gaps is {beta}{lambda}, where {lambda} is the free-space wavelength of the resonant mode. Adjacent accelerating cavities have oppositely directed electric fields, alternating in phase by 180 degrees. The chain of cavities operates in a {pi}/2 structure mode so the coupling cavities are nominally unexcited. The CCDTL configuration provides an rf structure with high shunt impedance for intermediate velocity charged particles, i.e., particles with energies in the 20-200 MeV range. 5 figs.
Source Terms for HFIR Beam Tube Shielding Analyses, and a Complete Shielding Analysis of the HB-3 Tube
Bucholz, J.A.
The High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory is in the midst of a massive upgrade program to enhance experimental facilities. The reactor presently has four horizontal experimental beam tubes, all of which will be replaced or redesigned. The HB-2 beam tube will be enlarged to support more guide tubes, while the HB-4 beam tube will soon include a cold neutron source.
Sheared bioconvection in a horizontal tube
O. A. Croze; E. E. Ashraf; M. A. Bees
The recent interest in using microorganisms for biofuels is motivation enough to study bioconvection and cell dispersion in tubes subject to imposed flow. To optimize light and nutrient uptake, many microorganisms swim in directions biased by environmental cues (e.g. phototaxis in algae and chemotaxis in bacteria). Such taxes inevitably lead to accumulations of cells, which, as many microorganisms have a density different to the fluid, can induce hydrodynamic instabilites. The large-scale fluid flow and spectacular patterns that arise are termed bioconvection. However, the extent to which bioconvection is affected or suppressed by an imposed fluid flow, and how bioconvection influences the mean flow profile and cell transport are open questions. This experimental study is the first to address these issues by quantifying the patterns due to suspensions of the gravitactic and gyrotactic green biflagellate alga Chlamydomonas in horizontal tubes subject to an imposed flow. With no flow, the dependence of the dominant pattern wavelength at pattern onset on cell concentration is established for three different tube diameters. For small imposed flows, the vertical plumes of cells are observed merely to bow in the direction of flow. For sufficiently high flow rates, the plumes progressively fragment into piecewise linear diagonal plumes, unexpectedly inclined at constant angles and translating at fixed speeds. The pattern wavelength generally grows with flow rate, with transitions at critical rates that depend on concentration. Even at high imposed flow rates, bioconvection is not wholly suppressed and perturbs the flow field.
Sulphidation resistance of composite boiler tube materials
Kish, Joseph [McMaster University; Eng, Philip [FPInnovations; Singbeil, Douglas [FPInnovations; Keiser, James R [ORNL
A lab-based testing program was undertaken to generate data to better define the sulphidation resistance of composite tubes installed in the lower-furnace section of black liquor recovery boilers. All composite tube cladding alloys tested were observed to have an acceptable corrosion rate at normal operating temperatures (up to 400 C) in the synthetic lower-furnace gaseous environment tested (1% H{sub 2}S-99% N{sub 2}). This acceptable corrosion resistance is due to the expected formation of a relatively protective chromium-rich inner sulphide scale. An increase in temperature up to 560 C was found to significantly increase the corrosion rate. Of the various alloys tested, Alloy HR11N exhibited the lowest corrosion rate at each of the three temperatures tested. Moreover, the corrosion rate was found not to be strongly dependent on the fabrication route (weld overlay versus co-extruded). To minimize corrosion, operating conditions that promote prolonged exposure to elevated temperatures in the lower-furnace section of black liquor recovery boilers should be avoided, regardless of the type of composite tube installed.
Abbett, Bill
THE DYNAMIC EVOLUTION OF TWISTED MAGNETIC FLUX TUBES IN A THREE-DIMENSIONAL CONVECTING FLOW. I. UNIFORMLY BUOYANT HORIZONTAL TUBES Y. Fan High Altitude Observatory, National Center for Atmospheric-dimensional numerical simulations of the dynamic evolution of uniformly buoyant, twisted horizontal magnetic flux tubes
Tube cutter tool and method of use for coupon removal
Nachbar, Henry D. (Ballston Lake, NY); Etten, Jr., Marvin P. (Ballston Lake, NY); Kurowski, Paul A. (Scotia, NY)
A tube cutter tool is insertable into a tube for cutting a coupon from a damaged site on the exterior of the tube. Prior to using the tool, the damaged site is first located from the interior of the tube using a multi-coil pancake eddy current test probe. The damaged site is then marked. A fiber optic probe is used to monitor the subsequent cutting procedure which is performed using a hole saw mounted on the tube cutter tool. Prior to completion of the cutting procedure, a drill in the center of the hole saw is drilled into the coupon to hold it in place.
Tube cutter tool and method of use for coupon removal
Nachbar, H.D.; Etten, M.P. Jr.; Kurowski, P.A.
A tube cutter tool is insertable into a tube for cutting a coupon from a damaged site on the exterior of the tube. Prior to using the tool, the damaged site is first located from the interior of the tube using a multi-coil pancake eddy current test probe. The damaged site is then marked. A fiber optic probe is used to monitor the subsequent cutting procedure which is performed using a hole saw mounted on the tube cutter tool. Prior to completion of the cutting procedure, a drill in the center of the hole saw is drilled into the coupon to hold it in place. 4 figs.
Recirculating wedges for metal-vapor plasma tubes
Hall, J.P.; Sawvel, R.M.; Draggoo, V.G.
A metal vapor laser is disclosed that recycles condensed metal located at the terminal ends of a plasma tube back toward the center of the tube. A pair of arcuate wedges are incorporated on the bottom of the plasma tube near the terminal ends. The wedges slope downward toward the center so that condensed metal may be transported under the force of gravity away from the terminal ends. The wedges are curved to fit the plasma tube to thereby avoid forming any gaps within the tube interior. 8 figures.
Recirculating wedges for metal-vapor plasma tubes
Hall, Jerome P. (Livermore, CA); Sawvel, Robert M. (Modesto, CA); Draggoo, Vaughn G. (Livermore, CA)
A metal vapor laser is disclosed that recycles condensed metal located at the terminal ends of a plasma tube back toward the center of the tube. A pair of arcuate wedges are incorporated on the bottom of the plasma tube near the terminal ends. The wedges slope downward toward the center so that condensed metal may be transported under the force of gravity away from the terminal ends. The wedges are curved to fit the plasma tube to thereby avoid forming any gaps within the tube interior.
Segmented lasing tube for high temperature laser assembly
Sawicki, Richard H. (Danville, CA); Alger, Terry W. (Tracy, CA); Finucane, Raymond G. (Pleasanton, CA); Hall, Jerome P. (Livermore, CA)
A high temperature laser assembly capable of withstanding operating temperatures in excess of 1500.degree. C. is described comprising a segmented cylindrical ceramic lasing tube having a plurality of cylindrical ceramic lasing tube segments of the same inner and outer diameters non-rigidly joined together in axial alignment; insulation of uniform thickness surround the walls of the ceramic lasing tube; a ceramic casing, preferably of quartz, surrounding the insulation; and a fluid cooled metal jacket surrounds the ceramic casing. In a preferred embodiment, the inner surface of each of the ceramic lasing tube segments are provided with a pair of oppositely spaced grooves in the wall thereof parallel to the center axis of the segmented cylindrical ceramic lasing tube, and both of the grooves and the center axis of the segmented cylindrical ceramic lasing tube lie in a common plane, with the grooves in each ceramic lasing tube segment in circumferential alignment with the grooves in the adjoining ceramic lasing tube segments; and one or more ceramic plates, all lying in a common plane to one another and with the central axis of the segmented ceramic lasing tube, are received in the grooves to provide additional wall area in the segmented ceramic lasing tube for collision and return to ground state of metastable metal atoms within the segmented ceramic lasing tube.
Guided wave acoustic monitoring of corrosion in recovery boiler tubing
Quarry, M J; Chinn, D J
Corrosion of tubing used in black-liquor recovery boilers is a major concern in all pulp and paper mills. Extensive corrosion in recovery boiler tubes can result in a significant safety and environmental hazard. Considerable plant resources are expended to inspect recovery boiler tubing. Currently, visual and ultrasonic inspections are primarily used during the annual maintenance shutdown to monitor corrosion rates and cracking of tubing. This Department of Energy, Office of Industrial Technologies project is developing guided acoustic waves for use on recovery boiler tubing. The feature of this acoustic technique is its cost-effectiveness in inspecting long lengths of tubes from a single inspection point. A piezoelectric or electromagnetic transducer induces guided waves into the tubes. The transducer detects fireside defects from the coldside or fireside of the tube. Cracking and thinning on recovery boiler tubes have been detected with this technique in both laboratory and field applications. This technique appears very promising for recovery boiler tube application, potentially expediting annual inspection of tube integrity.
Synthesis and characterization of Fe(III)-silicate precipitation tubes
Parmar, K.; Pramanik, A.K. [National Metallurgical Laboratory, Council of Scientific and Industrial Research, Burmamines, Jamshedpur 831007 (India)] [National Metallurgical Laboratory, Council of Scientific and Industrial Research, Burmamines, Jamshedpur 831007 (India); Bandyopadhya, N.R. [Bengal Engineering and Science University, Shibpur, Howrah 711103 (India)] [Bengal Engineering and Science University, Shibpur, Howrah 711103 (India); Bhattacharjee, S., E-mail: email@example.com [National Metallurgical Laboratory, Council of Scientific and Industrial Research, Burmamines, Jamshedpur 831007 (India)
Fe(III)-silicate precipitation tubes synthesized through 'silica garden' route have been characterized using a number of analytical techniques including X-ray diffraction, infrared spectroscopy, atomic force microscopy, scanning and transmission electron microscopy. These tubes are brittle and amorphous and are hierarchically built from smaller tubes of 5-10 nm diameters. They remain amorphous at least up to 650 {sup o}C. Crystobalite and hematite are the major phases present in Fe(III)-silicate tubes heated at 850 {sup o}C. Morphology and chemical compositions at the external and internal walls of these tubes are remarkably different. These tubes are porous with high BET surface area of 291.2 m{sup 2}/g. Fe(III)-silicate tubes contain significant amount of physically and chemically bound moisture. They show promise as an adsorbent for Pb(II), Zn(II), and Cr(III) in aqueous medium.
The Benjamin Shock Tube Problem in KULL
Ulitsky, M
The goal of the EZturb mix model in KULL is to predict the turbulent mixing process as it evolves from Rayleigh-Taylor, Richtmyer-Meshkov, or Kelvin-Helmholtz instabilities. In this report we focus on a simple example of the Richtmyer-Meshkov instability (which occurs when a shock hits an interface between fluids of different densities) without the complication of reshock. The experiment by Benjamin et al. involving a Mach 1.21 incident shock striking an air / SF6 interface, is a good one to model and understand before moving onto shock tubes that follow the growth of the turbulent mixing zone from first shock through well after reshock.
Effects of grids in drift tubes
Okamura M.; Yamauchi, H.
In 2011, we upgraded a 201 MHz buncher in the proton injector for the alternating gradient synchrotron (AGS) - relativistic heavy ion collider (RHIC) complex. In the buncher we installed four grids made of tungsten to improve the transit time factor. The grid installed drift tubes have 32 mm of inner diameter and the each grid consists of four quadrants. The quadrants were cut out precisely from 1mm thick tungsten plates by a computerized numerically controlled (CNC) wire cutting electrical discharge machining (EDM). The 3D electric field of the grid was simulated.
Sound Coiled-Tubing Drilling Practices
Williams, Thomas; Deskins, Greg (Maurer Technology Inc.); Ward, Stephen L. (Advantage Energy Services Ltd); Hightower, Mel
This Coiled-Tubing Drilling (CTD) Sound Practices Manual provides tools needed by CTD engineers and supervisors to plan, design and perform safe, successful CTD operations. As emphasized throughout, both careful planning and attention to detail are mandatory for success. A bibliography of many useful CTD references is presented in Chapter 6. This manual is organized according to three processes: 1) Pre-Job Planning Process, 2) Operations Execution Process, and 3) Post-Job Review Process. Each is discussed in a logical and sequential format.
The Monitored Drift Tube Chambers of Atlas
Ventura, S. [INFN - Laboratori Nazionali di Frascati (Italy)
The Atlas experiment has been designed to explore the high energy physics frontier at the TeV energy scale and to investigate on the physics of the Standard Model and beyond at the Large Hadron Collider (LHC) at Cern. The Muon Spectrometer represents the most part of the Atlas detector. It has been designed to provide standalone measurement of the transverse muon momenta with a relative accuracy of 3% over a wide momentum range up to 10% for momenta of 1 TeV. This high accuracy is provided by the Monitored Drift-Tube chambers (MDT) which can determine the track trajectory with a precision of 40 {mu}m.
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Fuel cell tubes and method of making same
Borglum, Brian P. (Edgewood, PA)
A method of manufacturing porous ceramic tubes for fuel cells with improved properties and higher manufacturing yield is disclosed. The method involves extruding a closed end fuel cell tube, such as an air electrode of a solid oxide fuel cell, in which the closed end also functions as the sintering support. The resultant fuel cell tube has a superior porosity distribution which allows improved diffusion of oxygen at the closed end of the tube during operation of the fuel cell. Because this region has the highest current density, performance enhancement and improved reliability of the fuel cell tube result. Furthermore, the higher manufacturing yield associated with the present method decreases the overall fuel cell cost. A method of manufacturing porous ceramic tubes for fuel cells with improved properties and higher manufacturing yield is disclosed. The method involves extruding a closed end fuel cell tube, such as an air electrode of a solid oxide fuel cell, in which the closed end also functions as the sintering support. The resultant fuel cell tube has a superior porosity distribution which allows improved diffusion of oxygen at the closed end of the tube during operation of the fuel cell. Because this region has the highest current density, performance enhancement and improved reliability of the fuel cell tube result. Furthermore, the higher manufacturing yield associated with the present method decreases the overall fuel cell cost.
Laced permanent magnet quadrupole drift tube magnets
Feinberg, B.; Behrsing, G.U.; Halbach, K.; Marks, J.S.; Morrison, M.E.; Nelson, D.H.
A laced permanent magnet quadrupole drift tube magnet has been constructed for a proof-of-principle test. The magnet is a conventional tape-wound quadrupole electromagnet, using iron pole- pieces, with the addition of permanent magnet material (neodymium iron) between the poles to reduce the effects of saturation. The iron is preloaded with magnetic flux generated by the permanent magnet material, resulting in an asymmetrical saturation curve. Since the polarity of the quadrupole magnets in a drift tube linac is not reversed we can take advantage of this asymmetrical saturation to provide greater focusing strength. The magnet configuration has been optimized and the vanadium permendur poles needed in a conventional quadrupole have been replaced with iron poles. The use of permanent magnet material has allowed us to increase the focusing strength of the magnet by about 20% over that of a conventional tape-wound quadrupole. Comparisons will be made between this magnet and the conventional tape-wound quadrupole. 3 refs., 5 figs.
Heat transfer in bundles of finned tubes in crossflow
Stasiulevicius, J.; Skrinska, A.; Zukauskas, A.; Hewitt, G.F.
This book provides correlations of heat transfer and hydraulic data for bundles of finned tubes in crossflow at high Reynolds numbers. Results of studies of the effectiveness of the fin, local, and mean heat transfer coefficients are presented. The effect of geometric parameters of the fins and of the location of tubes in the bundle on heat transfer and hydraulic drag are described. The resistance of the finned tube bundles under study and other factors are examined.
alloy pressure tubes: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
employed by India during this CRP and Indias performance on flaw detection and sizing in pressure tube samples. Based on the analysis of inspection results, the most...
Penetrameter positioner for bore-side radiography of tubes
Davis, E.V.; Foster, B.E.
A positioner is provided for placing plaque or wire penetrameters, as used in radiographic inspection, in close proximity with the inner wall of tubing at any desired location along the tubing. The positioner head carrying the penetrameter is inflatable whereby it is positioned in tte deflated condition, inflated to place the penetrameter against a weld to be inspected in the tubing wall, and then deflated during removal. If desired, the penetrameter holder may be used to center the radiographic source on the axis of the tube.
Method Of Making Closed End Ceramic Fuel Cell Tubes
Borglum, Brian P. (Edgewood, PA)
A method of manufacturing closed end ceramic fuel cell tubes with improved properties and higher manufacturing yield is disclosed. The method involves bonding an unfired cap to a hollow unfired tube to form a compound joint. The assembly is then fired to net shape without subsequent machining. The resultant closed end tube is superior in that it provides a leak-tight seal and its porosity is substantially identical to that of the tube wall. The higher manufacturing yield associated with the present method decreases overall fuel cell cost significantly.
Bore tube assembly for steam cooling a turbine rotor
DeStefano, Thomas Daniel (Ballston Lake, NY); Wilson, Ian David (Clifton Park, NY)
An axial bore tube assembly for a turbine is provided to supply cooling steam to hot gas components of the turbine wheels and return the spent cooling steam. A pair of inner and outer tubes define a steam supply passage concentric about an inner return passage. The forward ends of the tubes communicate with an end cap assembly having sets of peripheral holes communicating with first and second sets of radial tubes whereby cooling steam from the concentric passage is supplied through the end cap holes to radial tubes for cooling the buckets and return steam from the buckets is provided through the second set of radial tubes through a second set of openings of the end cap into the coaxial return passage. A radial-to-axial flow transitioning device, including anti-swirling vanes is provided in the end cap. A strut ring adjacent the aft end of the bore tube assembly permits axial and radial thermal expansion of the inner tube relative to the outer tube.
Glass heat pipe evacuated tube solar collector
McConnell, Robert D. (Lakewood, CO); Vansant, James H. (Tracy, CA)
A glass heat pipe is adapted for use as a solar energy absorber in an evacuated tube solar collector and for transferring the absorbed solar energy to a working fluid medium or heat sink for storage or practical use. A capillary wick is formed of granular glass particles fused together by heat on the inside surface of the heat pipe with a water glass binder solution to enhance capillary drive distribution of the thermal transfer fluid in the heat pipe throughout the entire inside surface of the evaporator portion of the heat pipe. Selective coatings are used on the heat pipe surface to maximize solar absorption and minimize energy radiation, and the glass wick can alternatively be fabricated with granular particles of black glass or obsidian.
Flash photolysis-shock tube studies
Michael, J.V. [Argonne National Laboratory, IL (United States)
Even though this project in the past has concentrated on the measurement of thermal bimolecular reactions of atomic species with stable molecules by the flash or laser photolysis-shock tube (FP- or LP-ST) method using atomic resonance absorption spectrometry (ARAS) as the diagnostic technique, during the past year the authors have concentrated on studies of the thermal decompositions of selected chlorocarbon molecules. These studies are necessary if the degradation of chlorine containing organic molecules by incineration are to be understood at the molecular level. Clearly, destruction of these molecules will not only involve abstraction reactions, when possible, but also thermal decomposition followed by secondary reactions of the initially formed atoms and radicals. Studies on the thermal decomposition of CH{sub 3}Cl are complete, and the curve-of-growth for Cl-atom atomic resonance absorption has been determined. The new thermal decomposition studies are similar to those already reported for CH{sub 3}Cl.
Variable-energy drift-tube linear accelerator
Swenson, Donald A. (Los Alamos, NM); Boyd, Jr., Thomas J. (Los Alamos, NM); Potter, James M. (Los Alamos, NM); Stovall, James E. (Los Alamos, NM)
A linear accelerator system includes a plurality of post-coupled drift-tubes wherein each post coupler is bistably positionable to either of two positions which result in different field distributions. With binary control over a plurality of post couplers, a significant accumlative effect in the resulting field distribution is achieved yielding a variable-energy drift-tube linear accelerator.
Analysis of tubes filled with charged electron gas
Stefan Karrmann
We show that tubes filled with electron gas, as presented by A.Bolonkin, are not possible with current materials. First, the pressure of the charges on the outer surface cancel almost all of the electrostatic pressure of the inner electrons. Second, due to the mutually repulsion most of the electrons are in the outmost shell of the tube and not individually free.
Aquifer Sampling Tube Results for Fiscal Year 2003
Hartman, Mary J.; Peterson, Robert E.
This report presents and discusses results of the fiscal year 2003 sampling event associated with aquifer tubes along the Columbia River in the northern Hanford Site. Aquifer tube data help define the extent of groundwater contamination near the river, determine vertical variations in contamination, monitor the performance of interim remedial actions near the river, and support impact studies.
Drift tube suspension for high intensity linear accelerators
Liska, D.J.; Schamaun, R.G.; Clark, D.C.; Potter, R.C.; Frank, J.A.
The disclosure relates to a drift tube suspension for high intensity linear accelerators. The system comprises a series of box-sections girders independently adjustably mounted on a linear accelerator. A plurality of drift tube holding stems are individually adjustably mounted on each girder.
The effect of roughness on aerosol deposition in tubes
Chavez, Mario Cesar
Experimental measurements of simulated roughness within tubes and the subsequent aerosol penetration performance through these tubes were conducted for a aerosol particle size range of 5 nm to 20 nm and a flow rate range of 28 L/min to 169.9 L...
Erosion of heat exchanger tubes in fluidized beds
Johnson, E.K.; Flemmer, R.L.C.
This final report describes the activities of the 3-year project entitled Erosion of Heat Exchanger Tubes In Fluidized Beds.'' which was completed at the end of 1990. Project accomplishments include the collection of a substantial body of wear data In a 24in. [times] 24in. fluidized bed, comparative wear results In a 6in. [times] 6in. fluidized bed, the development of a dragometer and the collection of a comprehensive set of drag force data in the 24in. [times] 24in. bed, Fast Fourier Transform (FFT) analysis of bubble probe data to establish dominant bubble frequencies in the 24in. [times] 24in. bed, the use of a heat flux gauge for measurement of heat transfer coefficients in the 24in. [times] 24in. bed and the modeling of the tube wear in the 24in. [times] 24in. bed. Analysis of the wear data from the 24in. square bed indicates that tube wear increases with increase in superficial velocity, and with increase in tube height. The latter effect is a result of the tubes higher up in the bed seeing greater movement of dense phase than tubes lower down In the bed. In addition, tube wear was found to decrease with increase in particle size, for constant superficial velocity. Three models of tube wear were formulated and provided acceptable prediction of wear when compared with the experimental data.
Heat exchanger with leak detecting double wall tubes
Bieberbach, George (Tampa, FL); Bongaards, Donald J. (Seminole, FL); Lohmeier, Alfred (Tampa, FL); Duke, James M. (St. Petersburg, all of, FL)
A straight shell and tube heat exchanger utilizing double wall tubes and three tubesheets to ensure separation of the primary and secondary fluid and reliable leak detection of a leak in either the primary or the secondary fluids to further ensure that there is no mixing of the two fluids.
Iterative Learning Control Applications to High Power Microwave Tubes
high�peak power microwave (HPM) sources typically operate in the single shot regime because commercial HPM systems that operate at modest repetition rates, two examples of which include a system based is then to implement the control algorithms on a physical tube in order to build a ``smart tube'' HPM source. By smart
Iterative Learning Control Applications to High Power Microwave Tubes
high-peak power microwave (HPM) sources typically operate in the single shot regime because commercial HPM systems that operate at modest repetition rates, two examples of which include a system based is then to implement the control algorithms on a physical tube in order to build a "smart tube" HPM source. By smart
Effects of hydrophilic surface treatment on evaporation heat transfer at the outside wall of horizontal tubes
Kim, Ho-Young
of horizontal tubes H.-Y. Kim a , B.H. Kang b,* a Thermal/Flow Control Research Center, Korea Institute hydrophilic treatment induces film flow on the tubes while sessile drops are formed on untreated tubes liquid film on horizontal low-finned tubes is 60�100% more efficient than that on plain tubes. When
Hierarchical Part-Based Detection of 3D Flexible Tubes: Application to CT Colonoscopy
Barbu, Adrian
operations (region growing). Fig. 1. The rectal tubes are flexible and have variable shape and appearance and tube segments to the whole flexible tube. To increase the speed of the algorithm, can- didate parts are generated using a voting strategy. The detected tube segments are combined into a flexible tube using
Proceedings: International Conference on Boiler Tube Failures and Heat Recovery Steam Generator (HRSG) Tube Failures and Inspections
Tube failures remain the leading cause of availability loss in conventional fossil plants and combined cycle/heat recovery steam generator (HRSG) plants. These conference proceedings address state-of-the-art practices and techniques worldwide for understanding and reducing tube failures.
Microhole Coiled Tubing Bottom Hole Assemblies
Don Macune
The original objective of the project, to deliver an integrated 3 1/8-inch diameter Measurement While Drilling (MWD) and Logging While Drilling (LWD) system for drilling small boreholes using coiled tubing drilling, has been achieved. Two prototype systems have been assembled and tested in the lab. One of the systems has been successfully tested downhole in a conventional rotary drilling environment. Development of the 3 1/8-inch system has also lead to development and commercialization of a slightly larger 3.5-inch diameter system. We are presently filling customer orders for the 3.5-inch system while continuing with commercialization of the 3 1/8-inch system. The equipment developed by this project will be offered for sale to multiple service providers around the world, enabling the more rapid expansion of both coiled tubing drilling and conventional small diameter drilling. The project was based on the reuse of existing technology whenever possible in order to minimize development costs, time, and risks. The project was begun initially by Ultima Labs, at the time a small company ({approx}12 employees) which had successfully developed a number of products for larger oil well service companies. In September, 2006, approximately 20 months after inception of the project, Ultima Labs was acquired by Sondex plc, a worldwide manufacturer of downhole instrumentation for cased hole and drilling applications. The acquisition provided access to proven technology for mud pulse telemetry, downhole directional and natural gamma ray measurements, and surface data acquisition and processing, as well as a global sales and support network. The acquisition accelerated commercialization through existing Sondex customers. Customer demand resulted in changes to the product specification to support hotter (150 C) and deeper drilling (20,000 psi pressure) than originally proposed. The Sondex acquisition resulted in some project delays as the resistivity collar was interfaced to a different MWD system and also as the mechanical design was revised for the new pressure requirements. However, the Sondex acquisition has resulted in a more robust system, secure funding for completion of the project, and more rapid commercialization.
Condensation of Refrigerant-11 on the outside of horizontal and inclined enhanced tubes
Domingo, N.
Heat transfer condensation tests with Refrigerant-11 were performed on the outside of a smooth tube and a variety of enhanced tubes oriented horizontally and at various tube inclinations. One smooth tube and seven enhanced (externally fluted, roped, spiraled, and externally finned) tubes of 2.54-cm (1-in.) nominal outside diameter and 1.17-m (4-ft) length were tested. Several of the tested tubes featured internal enhanced geometries, which were caused by the heat transfer enhancing geometry on the tube's external surface. Condensing heat transfer coefficients are reported as composite coefficients, which combine the resistance of the condensing film and the tube wall, and are based on total tube outside surface area. Results show that in the horizontal condensing mode, the rank order (best to worst) of the tube geometries tested was spiral-shaped tubes, rope-shaped tubes, smooth tube, externally finned tube, and externally fluted tube. For a spiral-shaped tube, horizontal composite coefficients were up to 2.0 times the corresponding horizontal smooth tube values. For tilt angles greater than or equal to 60/sup 0/ from the horizontal, the condensing performance of the externally fluted tube was best of all the tubes tested.
MURPHY, JAMES E [University of Nevada, Reno] [University of Nevada, Reno
The objective of this research project is to produce single crystal niobium (Nb) tubes for use as particle accelerator cavities for the Fermi laboratory�s International Linear Collider project. Single crystal Nb tubes may have superior performance compared to a polycrystalline tubes because the absence of grain boundaries may permit the use of higher accelerating voltages. In addition, Nb tubes that are subjected to the high temperature, high vacuum crystallization process are very pure and well annealed. Any impurity with a significantly higher vapor pressure than Nb should be decreased by the relatively long exposure at high temperature to the high vacuum environment. After application of the single crystal process, the surfaces of the Nb tubes are bright and shiny, and the tube resembles an electro polished Nb tube. For these reasons, there is interest in single crystal Nb tubes and in a process that will produce single crystal tubes. To convert a polycrystalline niobium tube into a single crystal, the tube is heated to within a few hundred ?C of the melting temperature of niobium, which is 2477 ?C. RF heating is used to rapidly heat the tube in a narrow zone and after reaching the operating temperature, the hot zone is slowly passed along the length of the tube. For crystallization tests with Nb tubes, the traverse rate was in the range of 1-10 cm per hour. All the crystallization tests in this study were performed in a water-cooled, stainless steel chamber under a vacuum of 5 x10-6 torr or better. In earliest tests of the single crystal growth process, the Nb tubes had an OD of 1.9 cm and a wall thickness of 0.15 mm. With these relatively small Nb tubes, the single crystal process was always successful in producing single crystal tubes. In these early tests, the operating temperature was normally maintained at 2200 ?C, and the traverse rate was 5 cm per hour. In the next test series, the Nb tube size was increased to 3.8 cm OD and the wall thickness was increased 0.18 mm and eventually to 0.21 mm. Again, with these larger tubes, single crystal tubes were usually produced by the crystallization process. The power supply was generally operated at full output during these tests, and the traverse rate was 5 cm per hour. In a few tests, the traverse rate was increased to 10 cm per hour, and at the faster traverse rate, single crystal growth was not achieved. In these tests with a faster traverse rate, it was thought that the tube was not heated to a high enough temperature to achieve single crystal growth. In the next series of tests, the tube OD was unchanged at 3.8 cm and the wall thickness was increased to 0.30 mm. The increased wall thickness made it difficult to reach an operating temperature above 2,000 ?C, and although the single crystal process caused a large increase in the crystal grains, no single crystal tubes were produced. It was assumed that the operating temperature in these tests was not high enough to achieve single crystal growth. In FY 2012, a larger power supply was purchased and installed. With the new power supply, temperatures above the melting point of Nb were easily obtained regardless of the tube thickness. A series of crystallization tests was initiated to determine if indeed the operating temperature of the previous tests was too low to achieve single crystal growth. For these tests, the Nb tube OD remained at 3.8 cm and the wall thickness was 0.30 mm. The first test had an operating temperature of 2,000 ?C. and the operating temperature was increased by 50 ?C increments for each successive test. The final test was very near the Nb melting temperature, and indeed, the Nb tube eventually melted in the center of the tube. These tests showed that higher temperatures did yield larger grain sizes if the traverse rate was held constant at 5 cm per hour, but no single crystal tubes were produced even at the highest operating temperature. In addition, slowing the traverse rate to as low as 1 cm per hour did not yield a single crystal tube regardless of operating temperature. At this time, it
Mining data on usage of electronic nicotine delivery systems (ENDS) from YouTube videos
Talbot, Prue
systems (ENDS) from YouTube videos My Hua, Henry Yip, PrueENDS) and conventional cigarettes in YouTube videos.Methods Video data from YouTube videos were analysed to
Benchmarking gyrokinetic simulations in a toroidal flux-tube
Chen, Y.; Parker, S. E.; Wan, W. [University of Colorado at Boulder, Boulder, Colorado 80309 (United States)] [University of Colorado at Boulder, Boulder, Colorado 80309 (United States); Bravenec, R. [Fourth-State Research, Austin, Texas 78704 (United States)] [Fourth-State Research, Austin, Texas 78704 (United States)
A flux-tube model is implemented in the global turbulence code GEM [Y. Chen and S. E. Parker, J. Comput. Phys. 220, 839 (2007)] in order to facilitate benchmarking with Eulerian codes. The global GEM assumes the magnetic equilibrium to be completely given. The initial flux-tube implementation simply selects a radial location as the center of the flux-tube and a radial size of the flux-tube, sets all equilibrium quantities (B, ?B, etc.) to be equal to the values at the center of the flux-tube, and retains only a linear radial profile of the safety factor needed for boundary conditions. This implementation shows disagreement with Eulerian codes in linear simulations. An alternative flux-tube model based on a complete local equilibrium solution of the Grad-Shafranov equation [J. Candy, Plasma Phys. Controlled Fusion 51, 105009 (2009)] is then implemented. This results in better agreement between Eulerian codes and the particle-in-cell (PIC) method. The PIC algorithm based on the v{sub ||}-formalism [J. Reynders, Ph.D. dissertation, Princeton University, 1992] and the gyrokinetic ion/fluid electron hybrid model with kinetic electron closure [Y. Chan and S. E. Parker, Phys. Plasmas 18, 055703 (2011)] are also implemented in the flux-tube geometry and compared with the direct method for both the ion temperature gradient driven modes and the kinetic ballooning modes.
Residual stresses in weld overlay tubes: A finite element study
Taljat, B.; Zacharia, T.; Wang, X.L.; Keiser, J.R. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.; Feng, Z. [Edison Welding Inst., Columbus, OH (United States); Jirinec, M.J. [Welding Services, Inc., Norcross, GA (United States)
Residual stresses and strains in a tube with circumferential weld overlay were analyzed by the finite element (FE) method. The objective of this work was to develop and verify a FE model, to determine the magnitude and distribution of residual stresses in the weld overlay tube, and to evaluate the significance of two contributing factors to residual stress: (1) difference in material properties between tube and weld material, and (2) thermal gradients in the weld. An axisymmetric FE model was developed to simulate the circumferential two-layer welding process of alloy 625 overlay on SA210 tube. The first layer was modeled as a gas metal arc welding process with filler metal, whereas the autogenous gas tungsten arc welding process was modeled for the second layer. Neutron diffraction technique was used to experimentally determine residual elastic strains in the weld overlay tube. Comparison with the FE results shows overall good agreement. Both the experimental and FE results show high compressive stresses at the inside tube surface and high tensile stresses in the weld overlay. This suggests that weld overlay may be used to relieve tensile or produce compressive stresses at the inside tube surface, which is significant for applications where crack initiation is found at the root pass of the joining weld.
The effect of charcoal tube geometry on breakthrough volume
Strange, Jay B.
on the breakthrough volume using parameters established by the National Institute for Occupational Safety and Health (NIOSH). Glass tubes with internal diameters of 2, 4 and 6 mm, each containing 100 mg of charcoal, were exposed to acetone concentrations... of approximately 1500, 750 and 375 ppm at flowrates of 200, 100 and 50 cc/min. The average bed lengths for the 2, 4 and 6 mm tubes were 57. 1, 14. 3 and 6. 3 mm respectively. Eighty-one hand packed charcoal tubes were used in twenty-seven experimental runs...
Why Do Kraft Recovery Boiler Composite Floor Tubes Crack?
Keiser, J.R.
Cracks were first reported in 1992 in co-extruded 304L stainless steel/SA210 Gd Al carbon steel floor tubes of North American black liquor recovery boilers. Since then, a considerable amount of information has been collected on the tube environment, crack characteristics, the stress state of the tubes, and the crack initiation and propagation mechanisms. These studies have identified both operating procedures that apparently can greatly lessen the likelihood of crack formation in the stainless steel layer and alternate materials that appear to be much more resistant to cracking than is 304L stainless.
Composite Tube Trailer Design/Manufacturing Needs | Department of Energy
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
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Heat transfer from a finned circular tube and from a finned streamlined tube by forced convection
Adams, David Michael
Ilimansions P/J' " Units 4. oj. Air static pressure drop a r oas I!. VV' not ele Ai. r static pressure drop across tost section and test chambe. Air stat' pressure drop across t'est acct~ on Air static pressure drop across L lenSth of duct.... ty of water Mass of dry air flowing through nozzle and duct Mass of water flowing through test section Reynolds Number over test section Reynolds Number over finned circular tube based on D' Nusselt Number for Dimensions L2 Units Used 2...
Coiled tubing drilling with supercritical carbon dioxide
Kolle , Jack J. (Seattle, WA)
A method for increasing the efficiency of drilling operations by using a drilling fluid material that exists as supercritical fluid or a dense gas at temperature and pressure conditions existing at a drill site. The material can be used to reduce mechanical drilling forces, to remove cuttings, or to jet erode a substrate. In one embodiment, carbon dioxide (CO.sub.2) is used as the material for drilling within wells in the earth, where the normal temperature and pressure conditions cause CO.sub.2 to exist as a supercritical fluid. Supercritical carbon dioxide (SC--CO.sub.2) is preferably used with coiled tube (CT) drilling equipment. The very low viscosity SC--CO.sub.2 provides efficient cooling of the drill head, and efficient cuttings removal. Further, the diffusivity of SC--CO.sub.2 within the pores of petroleum formations is significantly higher than that of water, making jet erosion using SC--CO.sub.2 much more effective than water jet erosion. SC--CO.sub.2 jets can be used to assist mechanical drilling, for erosion drilling, or for scale removal. A choke manifold at the well head or mud cap drilling equipment can be used to control the pressure within the borehole, to ensure that the temperature and pressure conditions necessary for CO.sub.2 to exist as either a supercritical fluid or a dense gas occur at the drill site. Spent CO.sub.2 can be vented to the atmosphere, collected for reuse, or directed into the formation to aid in the recovery of petroleum.
Aluminum Tape Evaluation for Sealable Aluminum Tubes Containing Mark 22 Fuel Tubes
As part of the HEU Blend Down project, aluminum tape is required to seal aluminum tubes that will hold contaminated Mark 22 fuel tubes for dissolution. From a large field of candidate tapes, Avery Dennison's Fasson 0802 tape (synthetic rubber adhesive system) was found to be acceptable for this application. This tape will disentangle in the normal H-Canyon dissolver solution and have no detrimental effect on the H-Canyon process. Upon placement of Fasson 0802 tape into the dissolver solution, nitric acid will attack and disentangle the block copolymer network and destroy the adhesive nature of the material, resulting in insoluble particles that can be removed via centrifuge operations (cake weight increase of no more than 1 percent). The addition of the tape will not generate off-gas products and the resultant solution characteristics (surface tension, viscosity, density, and disengagement time) will be unaffected. Further, the potential effect on the down-stream evaporation system is negligible. Since the tape will not be placed in a high radiation environment, radiation stability is not an issue. Through detailed discussions with Avery Dennison chemists and based on analytical tests, a fairly detailed understanding of the constituents comprising the proprietary adhesive system has been assembled. Most importantly, chlorine was not detected in the aluminum tape (neutron activation analysis detection limit is 16 ppm). Finally, application of this tape will not impact LEU specifications.
Pool boiling heat transfer enhancement over cylindrical tubes with water at atmospheric pressure, Part I: Experimental results
Kandlikar, Satish
tubes are generated by performing further pro- cesses on the finned tubes. They tested these surfaces and was fairly similar for all tubes. Huebner and Kuenstler [4] tested similar tubes with n-hexane and propane
automatic tube current: Topics by E-print Network
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G. S. Bali; K. Schilling 1997-09-25 100 Observation of flux tube crossings in the solar wind CERN Preprints Summary: Current sheets are ubiquitous in the solar wind.They are a...
Pressure tube testing test plan document production assurance program
Zaloudek, F.R. [Pacific Northwest Lab., Richland, WA (United States); Ruff, E.S. [UNC Nuclear Industries, Richland, WA (United States)
UNC Nuclear Industries (UNC) has initiated a plan for the manufacture of zirconium alloy pressure tubes required for the future operation of N-Reactor. As part of this plan, UNC is establishing a program to qualify and develop a manufacturing process capable of fabricating these pressure tubes to the requirements of UNC specification HWS 6502, REV 4, Amendment 1. The objective of the task described in this test plan is to support the UNC program by performing physical/chemical testing on prototype tubes sections produced or procured during FY-1986, 1987 and 1988 and to test samples from production runs after 1988 as may be required. The types of tests included in this pressure tube testing task will be as follows: (1) Tensile tests; (2) Burst testing; (3) Tests to evaluate fracture properties; (4) Corrosion tests; (5) Spectrographic analysis of chemical composition; (6) Metallographic evaluation of grain size and oxide layer thickness.
Design and Test of Tube & Shell Heat Exchangers for Potential
Design and Test of Tube & Shell Heat Exchangers for Potential OTEC Application Jeong-Tae Kwon1 University, South Korea 2Department of Mechanical Engineering, Sunmoon University, South Korea 3Offshore CCS
Midcontinent well operators learn advantages of coiled-tubing techniques
Lyle, D.
From well cleanup to velocity strings to squeeze jobs, more Midcontinent operators are adding coiled-tubing methods to their oilfield techniques. The advantages of these techniques are discussed.
Eddy sensors for small diameter stainless steel tubes.
Skinner, Jack L.; Morales, Alfredo Martin; Grant, J. Brian; Korellis, Henry James; LaFord, Marianne Elizabeth; Van Blarigan, Benjamin; Andersen, Lisa E.
The goal of this project was to develop non-destructive, minimally disruptive eddy sensors to inspect small diameter stainless steel metal tubes. Modifications to Sandia's Emphasis/EIGER code allowed for the modeling of eddy current bobbin sensors near or around 1/8-inch outer diameter stainless steel tubing. Modeling results indicated that an eddy sensor based on a single axial coil could effectively detect changes in the inner diameter of a stainless steel tubing. Based on the modeling results, sensor coils capable of detecting small changes in the inner diameter of a stainless steel tube were designed, built and tested. The observed sensor response agreed with the results of the modeling and with eddy sensor theory. A separate limited distribution SAND report is being issued demonstrating the application of this sensor.
Pressure drop with surface boiling in small-diameter tubes
Dr?mer, Thomas
Pressure drop for water flowing in small-diameter tubes under isothermal, nonboiling, and surface-boiling conditions was investigated. Experimental results for local pressure gradient and heattransfer coefficients are ...
Defect specific maintenance of SG tubes -- How safe is it?
Cizelj, L.; Mavko, B.; Dvorsek, T. [Jozef Stefan Institute, Ljubljana (Slovenia)
The efficiency of the defect specific plugging criterion for outside diameter stress corrosion cracking at tube support plates is assessed. The efficiency is defined by three parameters: (1) number of plugged tubes, (2) probability of steam generator tube rupture and (3) predicted accidental leak rate through the defects. A probabilistic model is proposed to quantify the probability of tube rupture, while procedures available in literature were used to define the accidental leak rates. The defect specific plugging criterion was then compared to the performance of traditional (45%) plugging criterion using realistic data from Krsko nuclear power plant. Advantages of the defect specific approach over the traditional one are clearly shown. Some hints on the optimization of safe life of steam generator are also given.
TiN Coatings on Fuel Cladding Tube�
Yu, Zhichao 1987-
demonstrate this new design and deposite TiN on the tubes. A systematic physical property study including surface characterization (SEM), mechanical testing (hardness and scratch test), thermal cycle test and thermal conductivity measurements, was conducted...
Design and fabrication of pressure-compensating compliant tubes
Martin, Ian (Ian P.)
Different fabrication methods are evaluated for producing pressure-compensating tubes for use in low-pressure drip irrigation systems. Such devices would allow drip irrigation systems to operate at driving pressures much ...
Flow of Navier-Stokes Fluids in Cylindrical Elastic Tubes
Sochi, Taha
Analytical expressions correlating the volumetric flow rate to the inlet and outlet pressures are derived for the time-independent flow of Newtonian fluids in cylindrically-shaped elastic tubes using a one-dimensional Navier-Stokes flow model with two pressure-area constitutive relations. These expressions for elastic tubes are the equivalent of Poiseuille and Poiseuille-type expressions for rigid tubes which were previously derived for the flow of Newtonian and non-Newtonian fluids under various flow conditions. Formulae and procedures for identifying the pressure field and tube geometric profile are also presented. The results are validated by a finite element method implementation. Sensible trends in the analytical and numerical results are observed and documented.
alloy clad tubes: Topics by E-print Network
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the reversal requires a certain relative velocity difference between plasma inside the flux tube and the environment, the ins... Holzwarth, Volkmar 2008-01-01 99 Liquid-core...
Continuous Flow Coupling and Decarboxylation Reactions Promoted by Copper Tubing
Zhang, Yun
A convenient and efficient flow method for Ullmann condensations, Sonogashira couplings, and decarboxylation reactions using a commercially available copper tube flow reactor (CTFR) is described. The heated CTFR effects ...
ab electronic tubes: Topics by E-print Network
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advanced pressure-tube (PT) reactor being developed by Atomic Energy of Canada Limited (AECL). As in conventional CANDU reactors, the PTs are horizontal. Each PT is surrounded by a...
aspiration neural tube: Topics by E-print Network
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advanced pressure-tube (PT) reactor being developed by Atomic Energy of Canada Limited (AECL). As in conventional CANDU reactors, the PTs are horizontal. Each PT is surrounded by a...
aluminium alloy tubes: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
advanced pressure-tube (PT) reactor being developed by Atomic Energy of Canada Limited (AECL). As in conventional CANDU reactors, the PTs are horizontal. Each PT is surrounded by a...
alloy tubes application: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
advanced pressure-tube (PT) reactor being developed by Atomic Energy of Canada Limited (AECL). As in conventional CANDU reactors, the PTs are horizontal. Each PT is surrounded by a...
advanced ceramic tube: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
advanced pressure-tube (PT) reactor being developed by Atomic Energy of Canada Limited (AECL). As in conventional CANDU reactors, the PTs are horizontal. Each PT is surrounded by a...
Refrigerant forced-convection condensation inside horizontal tubes
Bae, Soonhoon
High vapor velocity condensation inside a tube was studied theoretically. The heat transfer coefficients were calculated by the momentum and heat transfer analogy. The Von Karman universal velocity distribution was applied ...
Refrigerant forced-convection condensation inside horizontal tubes
Bae, Soonhoon
High vapor velocity condensation inside a tube was studied theoretically. The heat transfer coefficients were calculated by the momentum and heat transfer analogy. The Von Karman universal velocity distribution was applied ...
assessing tube wall: Topics by E-print Network
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tube drawing is a metal Paris-Sud XI, Universit de 35 LIFE CYCLE ASSESSMENT OF A HEMP CONCRETE WALL: IMPACT OF THICKNESS AND COATING. Physics Websites Summary: to reduce...
X-ray tube with magnetic electron steering
Reed, Kim W. (Albuquerque, NM); Turman, Bobby N. (Albuquerque, NM); Kaye, Ronald J. (Albuquerque, NM); Schneider, Larry X. (Albuquerque, NM)
An X-ray tube uses a magnetic field to steer electrons. The magnetic field urges electrons toward the anode, increasing the proportion of electrons emitted from the cathode that reach desired portions of the anode and consequently contribute to X-ray production. The magnetic field also urges electrons reflected from the anode back to the anode, further increasing the efficiency of the tube.
Methanation in catalyst-sprayed tube wall reactors: a review
Pennline, H. W.; Schehl, R. R.; Haynes, W. P.; Forney, A. J.
The design and operation of catalyst-sprayed tube wall reactors for methanation are discussed. Reactor tubes were either coated on the inner surface or on the outer surface with a Raney nickel catalyst. A liquid coolant, which was opposite the catalyst-reactant gas-side, removed the heat of methanation. Catalyst performance, reactor operating conditions, spent catalyst analyses, and other results are presented for five PDU tests.
Methods for batch fabrication of cold cathode vacuum switch tubes
Walker, Charles A. (Albuquerque, NM); Trowbridge, Frank R. (Albuquerque, NM)
Methods are disclosed for batch fabrication of vacuum switch tubes that reduce manufacturing costs and improve tube to tube uniformity. The disclosed methods comprise creating a stacked assembly of layers containing a plurality of adjacently spaced switch tube sub-assemblies aligned and registered through common layers. The layers include trigger electrode layer, cathode layer including a metallic support/contact with graphite cathode inserts, trigger probe sub-assembly layer, ceramic (e.g. tube body) insulator layer, and metallic anode sub-assembly layer. Braze alloy layers are incorporated into the stacked assembly of layers, and can include active metal braze alloys or direct braze alloys, to eliminate costs associated with traditional metallization of the ceramic insulator layers. The entire stacked assembly is then heated to braze/join/bond the stack-up into a cohesive body, after which individual switch tubes are singulated by methods such as sawing. The inventive methods provide for simultaneously fabricating a plurality of devices as opposed to traditional methods that rely on skilled craftsman to essentially hand build individual devices.
Recomplete deep hot wells successfully with coiled tubing
Garner, T.; Fleckenstein, W. [Bechtel Petroleum Operations, Tupman, CA (United States); Shelley, B. [Halliburton Energy Services, Bakersfield, CA (United States)
A squeeze reperforation procedure in the Elk Hills, California field using coiled tubing included contaminating excess cement and jetting it from the well bore to eliminate the need to drill out cement before shooting new perforations. The 324-7R well was producing 260 b/d of oil through 2 7/8-in. production tubing, with a 20,000-scf/bbl gas-oil ratio (GOR). Bottomhole static temperature was 250 F. After pumping a cement squeeze to 9,000 ft trough 1{1/2}-in. coiled tubing (CT) run inside the production tubing, oil production increased to 550 b/d of oil, and the GOR decreased to 5,000 scf/bbl when new perforations were shot. Cement was pumped 9,000 ft through the CT and circulated back through the production tubing/CT annulus. Operation cost was estimated at 20% less than for a comparable job performance with conventional tubing. Cost of the CT squeeze was recovered by 58 days incremental production.
Colour flux-tubes in static Pentaquark systems
Pedro Bicudo; Nuno Cardoso; Marco Cardoso
The colour fields created by the static tetraquark and pentaquark systems are computed in quenched SU(3) lattice QCD, with gauge invariant lattice operators, in a 24^3 x 48 lattice at beta=6.2 . We generate our quenched configurations with GPUs, and detail the respective benchmanrks in different SU(N) groups. While at smaller distances the coulomb potential is expected to dominate, at larger distances it is expected that fundamental flux tubes, similar to the flux-tube between a quark and an antiquark, emerge and confine the quarks. In order to minimize the potential the fundamental flux tubes should connect at 120o angles. We compute the square of the colour fields utilizing plaquettes, and locate the static sources with generalized Wilson loops and with APE smearing. The tetraquark system is well described by a double-Y-shaped flux-tube, with two Steiner points, but when quark-antiquark pairs are close enough the two junctions collapse and we have an X-shaped flux-tube, with one Steiner point. The pentaquark system is well described by a three-Y-shaped flux-tube where the three flux the junctions are Steiner points.
Observations of erosion of in-bed tubes in the Great Lake AFBC
Kantesaria, P.P.; Jukkola, G.D.
Erosion measurements have been made on evaporator tubes, superheater tubes and front wall tubes in the atmospheric, fluidised-bed combustor, demonstration plant at Great Lakes Naval Base, Chicago. A brief indication of the results obtained is given. High erosion rates on vertical tube surfaces were attributed to the tendency of bubbles rising through the bed to follow preferred paths along the vertical surfaces.
Apparatus and method for controlling heat transfer between a fluidized bed and tubes immersed therein
Hodges, James L. (3 Hilltop Ave., Vernon, CT 06066); Cerkanowicz, Anthony E. (8 Fieldstone Dr., Livingston, NJ 07039)
In a fluidized bed of solid particles having one or more heat exchange tubes immersed therein, the rate of heat transfer between the fluidized particles and a fluid flowing through the immersed heat exchange tubes is controlled by rotating an arcuate shield apparatus about each tube to selectively expose various portions of the tube to the fluidized particles.
Apparatus and method for controlling heat transfer between a fluidized bed and tubes immersed therein
Hodges, James L. (3 Hilltop Ave., Vernon, CT 06066); Cerkanowicz, Anthony E. (8 Fieldstone Dr., Livingston, NJ 07039)
In a fluidized bed of solid particles having one or more heat exchange tubes immersed therein, the rate of heat transfer between the fluidized particles and a fluid flowing through the immersed heat exchange tubes is controlled by rotating an arcuate shield apparatus about each tube to selectively expose various portions of the tube to the fluidized particles.
Method and apparatus for selective retraction of a tubing carried perforating gun
Rubbo, R.P.
This patent describes apparatus for telescopically retracting a subterranean well tubing carried perforating gun.
Facilitation of macroalgae by the sedimentary tube forming polychaete Diopatra cuprea
McGlathery, Karen
). Seventy percent of the number of mudflat macroalgae were found incorporated into protruding D. cuprea tube
Residual stress in laser welded dissimilar steel tube-to-tube joints
Sun, Zheng (Technical Research Centre of Finland, Espoo (Finland). Lab. of Production Engineering)
Austenitic-ferritic dissimilar steel joints are widely used in power generation systems. Their utilization has proved to be efficient in terms of satisfactory properties and the economics. These types of joints have usually been produced using conventional welding processes, such as tungsten inert gas (TIG) welding. With the rapid development of high power lasers, laser welding has received considerable attention. Laser welding offers many advantages over conventional welding processes, e.g. low heat input, small heat-affected zone (HAZ), small distortion, and welding in an exact and reproducible manner. Residual stress distribution in laser welds may also differ from those made by conventional welding processes due to its special features. Residual stress, particularly tensile residual stress in the weld, can be very important factor in controlling the quality and service life of the welded structure. The formation of tensile residual stress in the weld may result in the initiation of fatigue cracking, stress corrosion cracking or other types of fractures. It is useful, therefore, to understand the distribution of residual stress in austenitic-ferritic laser welds, and thus evaluate the quality of the joints. Although residual stress distribution in the welded joints has been extensively investigated, little data are available for the residual stress distribution in laser welds. The aim of the work was to examine residual stress distribution along laser welds of dissimilar steel tube-to-tube joints, which were made by both autogeneous welding and welding with filler wire. The results were also compared with the joints made by plasma arc and TIG welding.
Los Alamos National Laboratory W76 Pit Tube Lifetime Study
Abeln, Terri G. [Los Alamos National Laboratory
A metallurgical study was requested as part of the Los Alamos National Laboratory (LANL) W76-1 life-extension program (LEP) involving a lifetime analysis of type 304 stainless steel pit tubes subject to repeat bending loads during assembly and disassembly operations at BWXT/Pantex. This initial test phase was completed during the calendar years of 2004-2006 and the report not issued until additional recommended tests could be performed. These tests have not been funded to this date and therefore this report is considered final. Tubes were reportedly fabricated according to Rocky Flats specification P14548 - Seamless Type 304 VIM/VAR Stainless Steel Tubing. Tube diameter was specified as 0.125 inches and wall thickness as 0.028 inches. A heat treat condition is not specified and the hardness range specification can be characteristic of both 1/8 and 1/4 hard conditions. Properties of all tubes tested were within specification. Metallographic analysis could not conclusively determine a specified limit to number of bends allowable. A statistical analysis suggests a range of 5-7 bends with a 99.95% confidence limit. See the 'Statistical Analysis' section of this report. The initial phase of this study involved two separate sets of test specimens. The first group was part of an investigation originating in the ESA-GTS [now Gas Transfer Systems (W-7) Group]. After the bend cycle test parameters were chosen (all three required bends subjected to the same amount of bend cycles) and the tubes bent, the investigation was transferred to Terri Abeln (Metallurgical Science and Engineering) for analysis. Subsequently, another limited quantity of tubes became available for testing and were cycled with the same bending fixture, but with different test parameters determined by T. Abeln.
Reliability of steam generator tubes with axial cracks
Cizelj, L.; Mavko, B. [Jozef Stefan Inst., Ljubljana (Slovenia). Reactor Engineering Div.; Vencelj, P. [Univ. of Ljubljana (Slovenia). Faculty of Mathematics and Physics
An approach for estimating the failure probability of tubes containing through-wall axial cracks has already been proposed by the authors. It is based on probabilistic fracture mechanics and accounts for scatter in tube geometry and material properties, scatter in residual and operational stresses responsible for crack propagation, and characteristics of nondestructive examination and plugging procedures (e.g., detection probability, sizing accuracy, human errors). Results of preliminary tests demonstrated wide applicability of this approach and triggered some improvements. The additions to the model are extensively discussed in this paper. Capabilities are demonstrated by results of analysis of steam generator no. 1 in Slovenian nuclear power plant located in Krsko after the 1992 inspection and plugging campaign. First, the number of cracked tubes and the crack length distribution were estimated using data obtained by the 100% motorized pancake coil inspection. The inspection and plugging activities were simulated in the second step to estimate the efficiency of maintenance in terms of single and multiple-tube rupture probabilities. They were calculated as a function of maximum allowable crack length. The importance of human errors and some limitations of present nondestructive examination techniques were identified. The traditional wall thickness and crack-length-based plugging criteria are compared. The crack-length-based criterion is shown to be more efficient and more safe, especially because of strong suppression effect on probability of multiple-tube rupture. The results are considered to be important for safety and maintenance of existing plants and for further research.
The Dynamics of Flux Tubes in a High Beta Plasma
E. T. Vishniac
We suggest a new model for the structure of a magnetic field embedded high $\\beta$ turbulent plasma, based on the popular notion that the magnetic field will tend to separate into individual flux tubes. We point out that interactions between the flux tubes will be dominated by coherent effects stemming from the turbulent wakes created as the fluid streams by the flux tubes. Balancing the attraction caused by shielding effects with turbulent diffusion we find that flux tubes have typical radii comparable to the local Mach number squared times the large scale eddy length, are arranged in a one dimensional fractal pattern, have a radius of curvature comparable to the largest scale eddies in the turbulence, and have an internal magnetic pressure comparable to the ambient pressure. When the average magnetic energy density is much less than the turbulent energy density the radius, internal magnetic field and curvature scale of the flux tubes will be smaller than these estimates. Realistic resistivity does not alter the macroscopic properties of the fluid or the large scale magnetic field. In either case we show that the Sweet-Parker reconnection rate is much faster than an eddy turnover time. Realistic stellar plasmas are expected to either be in the ideal limit (e.g. the solar photosphere) or the resistive limit (most of the solar convection zone). All current numerical simulations of three dimensional MHD turbulence are in the viscous regime and are inapplicable to stars or accretion disks.
An improved model for flashing flow in short tubes
Tilton, J.D.; Kornhauser, A.A. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Mechanical Engineering
Short tube restrictors are commonly used as expansion devices in refrigeration and heat pumping systems. Flashing flow through short tubes is choked, i.e. independent of downstream conditions. Flow rate is typically predicted by empirically correcting the flow rate of compressed liquid from upstream pressure to saturation pressure at upstream temperature. The empirical correction factors depend on pressure and temperature, on short tube geometry, and on the refrigerant used. This work extends and improves a model of short tube flow based on the physics of the observed flow phenomena. Short tube flow is believed to consist of a core of superheated liquid surrounded by an annulus of vapor. Evaporation is driven by heat transfer form the core to tine interface, and the flow is choked by the evaporated vapor. Flow rate is modeled by calculating the heat transfer rate, the evaporation rate, and the choking effect of the vapor. The model attempts to improve on previous work by improving the accuracy with which thermodynamic properties are approximated, by improving the heat transfer model, and by including the effects of frictional heating of the liquid. In comparisons with experimental data it is found that the improved thermodynamic modeling increases accuracy, but the change to the heat transfer model reduces accuracy. For the data examined the effects of the frictional heating are small. The heat transfer model is based on an existing analytic solution with a mixing-length turbulence model. It appears that this model must be further improved, perhaps through empirical modification.
Heat exchanger performance calculations for enhanced-tube condenser applications
Rabas, T.J.
The lack of a prediction method is sometimes used for the rejection of enhanced tubes for some condenser applications even though there is ample data from single-tube condensing experiments. Three methods are discussed that can be used to rate and/or size these multitube units based on the single-tube experimental results. The Kern vertical-number correction appears to be quite adequate for most operating conditions, the exceptions being large sizes and/or deep vacuum operation. The bundle-factor method is preferred for these applications; however, field test results are required to obtain this factor. If performance data are not available, pointwise or numerical methods are required but special care must be taken to insure that the adverse effects of noncondensable gas pockets and the saturation-temperature depression are properly addressed.
Heat exchanger performance calculations for enhanced-tube condenser applications
Rabas, T.J.
The lack of a prediction method is sometimes used for the rejection of enhanced tubes for some condenser applications even though there is ample data from single-tube condensing experiments. Three methods are discussed that can be used to rate and/or size these multitube units based on the single-tube experimental results. The Kern vertical-number correction appears to be quite adequate for most operating conditions, the exceptions being large sizes and/or deep vacuum operation. The bundle-factor method is preferred for these applications; however, field test results are required to obtain this factor. If performance data are not available, pointwise or numerical methods are required but special care must be taken to insure that the adverse effects of noncondensable gas pockets and the saturation-temperature depression are properly addressed.
Friction Factor Measurements in an Equally Spaced Triangular Tube Array
Vassallo P, Symolon P
Friction factor data for adiabatic cross-flow of water in a staggered tube array was obtained over a Reynolds number range (based on hydraulic diameter and gap velocity) of about 10,000 to 250,000. The tubes were 12.7mm (0.5 inch) outer diameter, in a uniformly spaced triangular arrangement with a pitch-to-diameter ratio of 1.5. The friction factor was compared to several literature correlations, and was found to be best matched by the Idelchik correlation. Other correlations were found to vary significantly from the test data. Based on the test data, a new correlation is proposed for this tube bundle geometry which covers the entire Reynolds number range tested.
Thermal Behavior of Floor Tubes in a Kraft Recovery Boiler
Barker, R.E.; Choudhury, K.A.; Gorog, J.P.; Hall, L.M.; Keiser, J.R.; Sarma, G.B.
The temperatures of floor tubes in a slope-floored black liquor recovery boiler were measured using an array of thermocouples located on the tube crowns. It was found that sudden, short duration temperature increases occurred with a frequency that increased with distance from the spout wall. To determine if the temperature pulses were associated with material falling from the convective section of the boiler, the pattern of sootblower operation was recorded and compared with the pattern of temperature pulses. During the period from September, 1998, through February, 1999, it was found that more than 2/3 of the temperature pulses occurred during the time when one of the fast eight sootblowers, which are directed at the back of the screen tubes and the leading edge of the first superheater bank, was operating.
Improving Efficiency of Tube Drawing Bench | Department of Energy
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Method for forming a layer of synthetic corrosion products on tubing surfaces
Lane, Michael H. (Clifton Park, NY); Salamon, Eugene J. M. (Clifton Park, NY)
A method is provided for forming a synthetic corrosion product layer on tube surfaces. The method utilizes two dissimilar materials with different coefficients of thermal expansion. An object tube and sacrificial tube are positioned one inside the other such that an annular region is created between the two tubes' surfaces. A slurry of synthetic corrosion products is injected into this annular region and the assembly is heat treated. This heat causes the tubes to expand, the inner tube with the higher coefficient of expansion expanding more than the outer tube, thereby creating internal pressures which consolidate the corrosion products and adhere the corrosion products to the tubing surfaces. The sacrificial tube may then be removed by conventional chemical etching or mechanical methods.
Replacement of Mushroom Cage Gastrostomy Tube Using a Modified Technique to Allow Percutaneous Replacement with an Endoscopic Tube in Patients with Amyotrophic Lateral Sclerosis
Ammar, Thoraya [King's College Hospital, Department of Radiology (United Kingdom); Rio, Alan [King's College Hospital, Department of Dietetics (United Kingdom); Ampong, Mary Ann [King's College Hospital, Department of Neurosciences (United Kingdom); Sidhu, Paul S., E-mail: email@example.com [King's College Hospital, Department of Radiology (United Kingdom)
Radiologic inserted gastrostomy (RIG) is the preferred method in our institution for enteral feeding in amyotrophic lateral sclerosis (ALS). Skin-level primary-placed mushroom cage gastrostomy tubes become tight with weight gain. We describe a minimally invasive radiologic technique for replacing mushroom gastrostomy tubes with endoscopic mushroom cage tubes in ALS. All patients with ALS who underwent replacement of a RIG tube were included. Patients were selected for a modified replacement when the tube length of the primary placed RIG tube was insufficient to allow like-for-like replacement. Replacement was performed under local anesthetic and fluoroscopic guidance according to a preset technique, with modification of an endoscopic mushroom cage gastrostomy tube to allow percutaneous placement. Assessment of the success, safety, and durability of the modified technique was undertaken. Over a 60-month period, 104 primary placement mushroom cage tubes in ALS were performed. A total of 20 (19.2%) of 104 patients had a replacement tube positioned, 10 (9.6%) of 104 with the modified technique (male n = 4, female n = 6, mean age 65.5 years, range 48-85 years). All tubes were successfully replaced using this modified technique, with two minor complications (superficial wound infection and minor hemorrhage). The mean length of time of tube durability was 158.5 days (range 6-471 days), with all but one patient dying with a functional tube in place. We have devised a modification to allow percutaneous replacement of mushroom cage gastrostomy feeding tubes with minimal compromise to ALS patients. This technique allows tube replacement under local anesthetic, without the need for sedation, an important consideration in ALS.
Method and apparatus for remote tube crevice detection by current and voltage probe resistance measurement
Kikta, T.J.; Mitchell, R.D.
A method and apparatus for determining the extent of contact between an electrically conducting tube and an electrically conductive tubesheet surrounding the tube, based upon the electrical resistance of the tube and tubesheet. A constant current source is applied to the interior of the electrically conducting tube by probes and a voltmeter is connected between other probes to measure the voltage at the point of current injection, which is inversely proportional to the amount of contact between the tube and tubesheet. Namely, the higher the voltage measured by the voltmeter, the less contact between the tube and tubesheet. 4 figs.
Fouling characteristics of compact heat exchangers and enhanced tubes.
Panchal, C. B.; Rabas, T. J.
Fouling is a complex phenomenon that (1) encompasses formation and transportation of precursors, and (2) attachment and possible removal of foulants. A basic understanding of fouling mechanisms should guide the development of effective mitigation techniques. The literature on fouling in complex flow passages of compact heat exchangers is limited; however, significant progress has been made with enhanced tubes.
Novel rotating field probe for inspection of tubes
Xin, J.; Tarkleson, E.; Lei, N.; Udpa, L.; Udpa, S. S. [Nondestructive Evaluation Laboratory, Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, 48824 (United States)
Inspection of steam generator tubes in nuclear power plants is extremely critical for safe operation of the power plant. In the nuclear industry, steam generator tube inspection using eddy current techniques has evolved over the years from a single bobbin coil, to rotating probe coil (RPC) and array probe, in an attempt to improve the speed and reliability of inspection. The RPC probe offers the accurate spatial resolution but involves complex mechanical rotation. This paper presents a novel design of eddy current probes based on rotating fields produced by three identical coils excited by a balanced three-phase supply. The sensor thereby achieves rotating probe functionality by electronic means and eliminates the need for mechanical rotation. The field generated by the probe is largely radial that result in induced currents that flow circularly around the radial axis and rotating around the tube at a synchronous speed effectively producing induced eddy currents that are multidirectional. The probe will consequently be sensitive to cracks of all orientations in the tube wall. The finite element model (FEM) results of the rotating fields and induced currents are presented. A prototype probe is being built to validate simulation results.
Field stability in two-stem drift-tube linacs
Billen, J.H.; Spalek, G.; Shapiro, A.H.
Drift tubes supported by two stems have been considered for cryogenic drift-tube linacs (DTLs) to reduce vibrations and to minimize drift-tube deflections upon cool down. We investigated rf properties of two-stem DTL structures at room temperature and low power. Even apart is inherently more stable against tuning errors than a similar structure with single stems. The increased stability is higher for DTLs with shorter drift tubes. Ordinary quarter-wavelength-long post couplers actually destabilize the two-stem DTL fields; the extra stem raises the post coupler frequency compared to the frequency of the same post coupler extended beyond the tank wall into coaxial stub tuners. Adjustment of the stub lengths tunes the post-coupler frequencies, but post-coupler lengths in the tank have no effect, which suggests a field pattern different from traditional post couplers. The stabilized DTL resembles multiple-stem DTLs in which the angle between stems is varied to achieve stabilization. Adjusting the coaxial stub length is mechanically simpler than changing the stem azimuth angle. 5 refs., 6 figs., 1 tab.
Etching of Copper Coated Mylar Tubes With CF-4 Gas
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Ecklund, Karl M.; Hartman, Keith W.; Hebert, Michael J.; Wojcicki, Stanley G.
Using 5 mm diameter copper coated mylar straw tubes at a potential of 2.30 KV relative to a concentric 20 (mu)m diameter gold-plated tungsten anode, it has been observed that with very low flow rates of CF4-based gases the conductive copper cathode material may be removed entirely from the mylar surface.
Visualizing YouTube Video Clusters Derek Thrasher
Mountziaris, T. J.
Visualizing YouTube Video Clusters Derek Thrasher University of Massachusetts Amherst REU Student Faculty Adviser: Lixin Gao Abstract In recent years, video streaming has become a significant part of our everyday lives. Advertisers, media companies, and video up-loaders are interested in what makes a video
Surface Evolution of Crystalline Tubes Fuqian Yang a
Zhang, Jun
of lattice diffusion and linear stability analysis. Without surface disturbance the annular tube will shrink on the dependence of perturbation growth rate on perturbation frequency. The perturbation will grow when the perturbation frequency is less than the critical frequency, which is equal to the inverse of the inner surface
Behaviour of Magnetic Tubes in Neutron Star's Interior
R. S. Singh; B. K. Sinha; N. K. Lohani
It is found from Maxwell's equations that the magnetic field lines are good analogues of relativistic strings. It is shown that the super-conducting current in the neutron star's interior causes local rotation of magnetic flux tubes carrying quantized flux.
DOE/ANL/HTRI heat exchanger tube vibration data bank
Halle, H.; Chenoweth, J.M.; Wambsganss, M.W.
This addendum to the DOE/ANL/HTRI Heat Exchanger Tube Vibration Data Bank includes 16 new case histories of field experiences. The cases include several exchangers that did not experience vibration problems and several for which acoustic vibration was reported.
Ultrasonic Concentration in a Line-Driven Cylindrical Tube
G.R. Goddard
The fractionation of particles from their suspending fluid or noninvasive micromanipulation of particles in suspension has many applications ranging from the recovery of valuable reagents from process flows to the fabrication of microelectromechanical devices. Techniques based on size, density, solubility, or electromagnetic properties exist for fulfilling these needs, but many particles have traits that preclude their use such as small size, neutral buoyancy, or uniform electromagnetic characteristics. While separation by those techniques may not be possible, often compressibility differences exist between the particle and fluid that would allow fractionation by acoustic forces. The potential of acoustic separation is known, but due to inherent difficulties in achieving and maintaining accurate alignment of the transduction system, it is rarely utilized. The objective of this project is to investigate the use of structural excitation as a potentially efficient concentration/fractionation method for particles in suspension. It is demonstrated that structural excitation of a cylindrically symmetric cavity, such as a tube, allows non-invasive, fast, and low power concentration of particles suspended in a fluid. The inherent symmetry of the system eliminates the need for careful alignment inherent in current acoustic concentration devices. Structural excitation distributes the acoustic field throughout the volume of the cavity, which also significantly reduces temperature gradients and acoustic streaming in the fluid; cavitation is no longer an issue. The lowest-order coupled modes of a long cylindrical glass tube and fluid-filled cavity, driven by a line contact, are tuned, via material properties and aspect ratio, to achieve a coupled dipolar vibration of the system, shown to generate efficient concentration of particles to the central axis of the tube. A two dimensional elastodynamic model of the system was developed and subsequently utilized to optimize particle concentration within the system. The effects of tubing, fluid, and particle material properties, tube geometry, fluid flow, and tube length on the structural excitation and consequently power requirements and concentration quality within the tube were investigated theoretically and experimentally. Limitations of the method are discussed, as well as ways to minimize or compensate for deleterious effects. Finally a preliminary demonstration of the efficacy of acoustic concentration is presented.
Groundwater contaminated with hexavalent chromium, strontium-90, and uranium discharges into the Columbia River along approximately 16 km (10 mi) of the shoreline. Various treatment systems have and will continue to be implemented to eliminate the impact of Hanford Site contamination to the river. To optimize the various remediation strategies, it is important to understand interactions between groundwater and the surface water of the Columbia River. An automated system to record water levels in aquifer sampling tubes installed in the hyporheic zone was designed and tested to (1) gain a more complete understanding of groundwater/river water interactions based on gaining and losing conditions ofthe Columbia River, (2) record and interpret data for consistent and defensible groundwater/surface water conceptual models that may be used to better predict subsurface contaminant fate and transport, and (3) evaluate the hydrodynamic influence of extraction wells in an expanded pump-and-treat system to optimize the treatment system. A system to measure water levels in small-diameter aquifer tubes was designed and tested in the laboratory and field. The system was configured to allow manual measurements to periodically calibrate the instrument and to permit aquifer tube sampling without removing the transducer tube. Manual measurements were collected with an e-tape designed and fabricated especially for this test. Results indicate that the transducer system accurately records groundwater levels in aquifer tubes. These data are being used to refine the conceptual and numeric models to better understand interactions in the hyporheic zone of the Columbia River and the adjacent river water and groundwater, and changes in hydrochemistry relative to groundwater flux as river water recharges the aquifer and then drains back out in response to changes in the river level.
Vertical-tube aqueous LiBr falling film absorption using advanced surfaces
Miller, W.A. [Oak Ridge National Lab., TN (United States); Perez-Blanco, H. [Pennsylvania State Univ., University Park, PA (United States)
A heat and mass transfer test stand was fabricated and used to investigate nonisothermal falling film absorption of water vapor into a solution of aqueous lithium bromide. The absorber was made of borosilicate glass for visual inspection of the failing film. Experiments were conducted on internally cooled tubes of about 0.019 m outside diameter and of 1.53 m length. Testing evaluated a single absorber tube`s performance at varying operating conditions, namely different cooling-water flow rates, solution flow rates, pressures, temperatures, and concentrations. Advanced surfaces were identified that enhanced absorber load and the mass of absorbed vapor. A pin-fin tube with 6.4mm pitch absorbed about 225% more mass than did a smooth tube. A grooved tube was the d best performer with 175% enhancement over the smooth tube. Increasing the cooling water flow rate to 1.893 {times} 10{sup {minus}4} m{sup 3}/s caused about a 300% increase in the mass absorbed for the grooved tube compared with the smooth tube. Results showed that the pin-fin tube with 6.4-mm pitch and the grooved tubes may enhance absorption to levels comparable to chemical enhancement in horizontal smooth tube absorbers. Absorber load, the transport coefficients, and pertinent absorption data are presented as functions of dimensionless numbers. These experimental data will prove useful in formulating analytical tools to predict vertical-tube absorber performance.
Ion-induced swelling of ODS ferritic alloy MA957 tubing to 500...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Ion-induced swelling of ODS ferritic alloy MA957 tubing to 500 dpa. Ion-induced swelling of ODS ferritic alloy MA957 tubing to 500 dpa. Abstract: In order to study the potential...
Computer Physics Communications 1 Aging Studies for the Large Honeycomb Drift Tube System of the
Tracker consists of drift tubes folded from polycarbonate foil and is operated with Ar/CF4/CO2 as drift for the drift tubes (surface conductivity, drift gas, production materials) have been developed and validated
Computer Physics Communications 1 Aging Studies for the Large Honeycomb Drift Tube System of the
of drift tubes folded from polycarbonate foil and is operated with Ar/CF 4 /CO 2 as drift gas. The detector tubes (surface conductivity, drift gas, production materials) have been developed and validated for use
An overview of the nondestructive inspection techniques for coiled tubing and pipe
Stanley, R.K. [Quality Tubing, Inc., Houston, TX (United States)
Coiled steel tubing and pipe in the diameter range 20--90 mm (0.75--3.5 in.) are replacing conventional oilfield materials for a variety of purposes including workovers, drilling, production tubing, umbilicals, and flowlines. They offer all the advantages of long tubes with no threaded connections. Because coiled tubing is being produced to high quality standards, it is lasting longer than ever before, and the need has arisen for careful nondestructive inspection at frequent intervals to determine accumulated damage to the string and the need for repair. Currently, derating of used coiled tubing using nondestructive testing (NDT) is not performed. While NDT devices for oilfield tubulars have been well documented, little has been written regarding the NDT of coiled tubing. This paper outlines the current NDT methods used during the manufacture of new tubing and the inspection of used coiled tubing.
DOE - Office of Legacy Management -- U S Steel Co National Tube...
Office of Legacy Management (LM)
CO., NATIONAL TUBE DIV., CHRISTY PARK WORKS PA.35-1 - NLO Trip Report; Halcomb to Quigley; Subject: Trip Report to National Tube Division, Christy Park Works, McKeesport,...
Tube vibration in industrial-size test heat exchanger (90/sup 0/ square layout)
Halle, H.; Wambsganss, M.W.
Tube vibrations in heat exchangers are being systematically investigated in a series of tests performed with an industrial-size test exchanger. Results from waterflow tests of eleven different tube bundles, in six- and eight-crosspass configurations on a 90/sup 0/ square layout with a pitch-to-diameter ratio of 1.25 are reported. The test cases include full tube bundles, no-tubes-in-window bundles, finned tube bundles, and proposed field and design fixes. The testing focused on identification of the lowest critical flowrate to initiate fluidelastic instability (large amplitude tube motion) and the location within the bundle of the tubes which first experience instability. The test results are tabulated to permit comparison with results obtained from previous tests with a 30/sup 0/ triangular layout tube bundle. Instability criteria are evaluated preliminarily. Pressure drop data are also generated and reported.
Investigation of heat transfer augmentation through use of internally finned and roughened tubes : final summary report
Bergles A. E.
This report summarizes a three-year program concerned with obtaining basic design information for tubes having a random roughness on the inside wall (RID) and tubing having continuous internal fins (Forge Fin). Test apparatus ...
Film boiling of saturated liquid flowing upward through a heated tube : high vapor quality range
Laverty, W. F.
Film boiling of saturated liquid flowing upward through a uniformly heated tube has been studied for the case in which pure saturated liquid enters the tube and nearly saturated vapor is discharged. Since a previous study ...
A Prediction Model for Adiabatic and Diabatic Capillary Tubes with Alternative Refrigerants�
Zhang, Yupeng
The capillary tube is a very common throttling device located between the condenser and evaporator in a refrigeration system. In some refrigerant systems, a section of the capillary tube is connected to a section of the ...
Eddy Current Signature Classification of Steam Generator Tube Defects Using A Learning Vector Quantization Neural Network
Gabe V. Garcia
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.
A Transformer Coupling Method for Imaging Defects in Concentrically Arranged Steel Tubes
Miller, G.; Hussin, H.; Fernandes, B.; Zaid, M.; Gaydecki, P.; El-Madaani, F. [School of Electrical and Electronic Engineering, University of Manchester, PO Box 88, Manchester M60 1QD (United Kingdom)
This paper describes the development of a system that uses a transformer coupling method for imaging defects in the outer tube of a concentric steel tube pair. Transformer coupling is employed where a receiver is mounted opposite to the transmitter. Magnetic field coupling is used, in which the field propagates through the inner steel tube towards the outer steel tube. Defects in the outer section distort the field and the change is detected by the receiver.
contains recent developments on a dynamic heat transfer model for a mono-tube steam cavity boiler, which
SciTech Connect: Numerical solution of shock tube divertor and...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Publication: United States Language: English Subject: N70300* --Physics--Controlled Thermonuclear Research-- Kinetics (General); *DIVERTORS-- MATHEMATICAL MODELS; *SHOCK TUBES--...
Heat Transfer Measurements for a Horizontal Micro-Tube Using Liquid Crystal Thermography
Ghajar, Afshin J.
62 TC02-007 Heat Transfer Measurements for a Horizontal Micro-Tube Using Liquid Crystal thermography (LCT) method was developed for surface temperature measurements on a horizontal 2000m macro-tube and 1000m micro-tube. In the single-phase heat transfer experiments, the fully-developed flow heat transfer
Tube foot preservation in the Devonian crinoid Codiacrinus from the Lower Devonian Hunsruck Slate, Germany
Kammer, Thomas
Tube foot preservation in the Devonian crinoid Codiacrinus from the Lower Devonian Hunsruck Slate.W. 2013: Tube foot preservation in the Devonian crinoid Codiacrinus from the Lower Devonian Hunsruck Slate Follmann from the Lower Devonian Hunsruck Slate of Germany. This is the first definitive proof of tube feet
Film condensation of R-113 on in-line bundles of horizontal finned tubes
Honda, H. (Kyushu Univ., Fukuoka (Japan)); Uchima, B.; Nozu, S.; Nakata, H.; Torigoe, E. (Okayama Univ. (Japan))
Film condensation of R-113 on in-line bundles of horizontal finned tubes with vertical vapor downflow was experimentally investigated. Two tubes with flat-sided annular fins and four tubes with three-dimensional fins were tested. The test sections were 3 {times} 15 tube bundles with and without two rows of inundation tubes at the top. Heat transfer measurements were carried out on a row-by-row basis. The heat transfer enhancement due to vapor shear was much less for a finned tube bundle than for a smooth tube bundle. The decrease in heat transfer due to condensate inundation was more marked for a three-dimensional fin tube than for a flat-sided fin tube. The predictions of the previous theoretical model for a bundle of flat-sided fin tubes agreed well with the measured data for low vapor velocity and a small to medium condensate inundation rate. Among the six tubes tested, the highest heat transfer performance was provided by the flat-sided fin tube with fin dimensions close to the theoretically determined optimum values.
New Regenerator Materials for use in pulse tube coolers
A. Kashani; B.P.M. Helvensteijn; P. Kittel; K.A. Gschneidner,jr; V.K. Pecharsky; A.O. Pecharsky
A two-stage pulse tube cooler driven by a linear compressor is being developed to provide cooling at 20 K. The first stage of the cooler will have the conventional stainless steel screen regenerator matrix. The matrix for the second stage regenerator (<60 K) will be made from a new class of Er based alloys which was recently developed at Ames Laboratory, in Ames, Iowa. These alloys exhibit heat capacities that exceed that of all other materials, including lead, over a Wide range in temperature (15 K < T C 85 K). The performance of one such alloy was shown to be better than lead when tested in a single-stage pulse tube cooler driven by a G-M compressor and operating at 2 Hz. An effort is underway to establish their suitability at frequencies above 40 IIZ. An approach to testing these alloys at low temperatures while using a low-power linear compressor is presented.
Low Power Photomultiplier Tube Circuit And Method Thereor
Bochenski, Edwin B. (Tracy, CA); Skinner, Jack L. (Brentwood, CA); Dentinger, Paul M. (Sunol, CA); Lindblom, Scott C. (Tracy, CA)
An electrical circuit for a photomultiplier tube (PMT) is disclosed that reduces power consumption to a point where the PMT may be powered for extended periods with a battery. More specifically, the invention concerns a PMT circuit comprising a low leakage switch and a high voltage capacitor positioned between a resistive divider and each of the PMT dynodes, and a low power control scheme for recharging the capacitors.
Automatic Tube Cleaning Systems for Condensers and Heat Exchangers
Someah, K.
and wiping action of the balls which prevents the de position of scale forming deposits inside the tube surface. The balls are collected by means of a special strainer installed in the outlet part of the condenser. The balls are then recirculated... and re injected back into the supply line. The major components of this type of cleaning systems are the ball strainer, the ball recirculation system and the control system. The ball collection is accomplished by two half sized electrical screens...
Rotor for processing liquids using movable capillary tubes
Johnson, W.F.; Burtis, C.A.; Walker, W.A.
A rotor assembly for processing liquids, especially whole blood samples, is disclosed. The assembly includes apparatus for separating non-liquid components of whole blood samples from liquid components, apparatus for diluting the separated liquid component with a diluent and apparatus for transferring the diluted sample to an external apparatus for analysis. The rotor assembly employs several movable capillary tubes to handle the sample and diluents. A method for using the rotor assembly to process liquids is also described. 5 figs.
Rotor for processing liquids using movable capillary tubes
Johnson, Wayne F. (Loudon, TN); Burtis, Carl A. (Oak Ridge, TN); Walker, William A. (Knoxville, TN)
A rotor assembly for processing liquids, especially whole blood samples, is disclosed. The assembly includes apparatus for separating non-liquid components of whole blood samples from liquid components, apparatus for diluting the separated liquid component with a diluent and apparatus for transferring the diluted sample to an external apparatus for analysis. The rotor assembly employs several movable capillary tubes to handle the sample and diluents. A method for using the rotor assembly to process liquids is also described.
Rotor for processing liquids using movable capillary tubes
Johnson, Wayne F. (Loudon, TN); Burtis, Carl A. (Oak Ridge, TN); Walker, William A. (Knoxville, TN)
A rotor assembly for processing liquids, especially whole blood samples, is disclosed. The assembly includes apparatus for separating non-liquid components of whole blood samples from liquid components, apparatus for diluting the separated liquid component with a diluent and apparatus for transferring the diluted sample to an external apparatus for analysis. The rotor assembly employs several movable capillary tubes to handle the sample and diluents. A method for using the rotor assembly to process liquids is also described.
Determination of the Number of Tube Rows to Obtain Closure for Volume Averaging Theory Based Model of Fin-and-Tube Heat Exchangers
Zhou, Feng; Hansen, Nicholas E; Geb, David J; Catton, Ivan
can be evaluated for a representative elementary volume (and-tube heat exchanger, representative elementary volumeand (2) on a selected representative elementary volume (REV)
Confinement and the Short Type I' Flux Tube
Shyamoli Chaudhuri
We show that the recent world-sheet analysis of the quantum fluctuations of a short flux tube in type II string theory leads to a simple and precise description of a pair of stuck D0branes in an orientifold compactification of the type I' string theory. The existence of a stable type I' flux tube of sub-string-scale length is a consequence of the confinement of quantized flux associated with the scalar dualized ten-form background field strength *F_{10}, evidence for a -2brane in the BPS spectrum of M theory. Using heterotic-type I duality, we infer the existence of an M2brane of finite width O(\\sqrt{\\alpha'}) in M-theory, the strong coupling resolution of a spacetime singularity in the D=9 twisted and toroidally compactified E_8 x E_8 heterotic string. This phenomenon has a bosonic string analog in the existence of a stable short electric flux tube arising from the confinement of photons due to tachyon field dynamics. The appendix clarifies the appearance of nonperturbative states and enhanced gauge symmetry in toroidal compactifications of the type I' string. We account for all of the known disconnected components of the moduli space of theories with sixteen supercharges, in striking confirmation of heterotic-type I duality.
Experimental study of curved guide tubes for pellet injection
Combs, S.K.; Baylor, L.R.; Foust, C.R.; Gouge, M.J.; Jernigan, T.C.; Milora, S.L.
The use of curved guide tubes for transporting frozen hydrogen pellets offers great flexibility for pellet injection into plasma devices. While this technique has been previously employed, an increased interest in its applicability has been generated with the recent ASDEX Upgrade experimental data for magnetic high-field side (HFS) pellet injection. In these innovative experiments, the pellet penetration appeared to be significantly deeper than for the standard magnetic low-field side injection scheme, along with corresponding greater fueling efficiencies. Thus, some of the major experimental fusion devices are planning experiments with HFS pellet injection. Because of the complex geometries of experimental fusion devices, installations with multiple curved guide tube sections will be required for HFS pellet injection. To more thoroughly understand and document the capability of curved guide tubes, an experimental study is under way at the Oak Ridge National Laboratory (ORNL). In particular, configurations and pellet parameters applicable for the DIII-D tokamak and the International Thermonuclear Experimental Reactor (ITER) were simulated in laboratory experiments. Initial test results with nominal 2.7- and 10-mm-diam deuterium pellets are presented and discussed.
Superior Corrosion Resistance Properties of TiN-Based Coatings on Zircaloy Tubes in Supercritical Water
Fauzia Khatkhatay; Liang Jiao; Jie Jian; Zhijie Jiao; Hongbin Zhang; Jian Gan; Haiyan Wang; Wenrui Zhang; Xinghang Zhang
Thin films of TiN and Ti0.35Al0.65N nanocomposite were deposited on polished Zircaloy-4 tubes. After exposure to supercritical water for 48 h, the coated tubes are remarkably intact, while the bare uncoated tube shows severe oxidation and breakaway corrosion. X-ray diffraction patterns, secondary electron images, backscattered electron images, and energy dispersive X-ray spectroscopy data from the tube surfaces and cross-sections show that a protective oxide, formed on the film surface, effectively prevents further oxidation and corrosion to the Zircaloy-4 tubes. This result demonstrates the effectiveness of thin film ceramics as protective coatings under extreme environments.
Direct Measurements of Pore Fluid Density by Vibrating Tube Densimetry
Gruszkiewicz, Miroslaw {Mirek} S [ORNL; Rother, Gernot [ORNL; Wesolowski, David J [ORNL; Cole, David R [ORNL; Wallacher, Dirk [Helmholtz-Zentrum Berlin
The densities of pore-confined fluids were measured for the first time by means of a vibrating tube method. Isotherms of total adsorption capacity were measured directly making the method complementary to the conventional gravimetric or volumetric/piezometric adsorption techniques, which yield the excess adsorption (the Gibbsian surface excess). A custom-made high-pressure, high-temperature vibrating tube densimeter (VTD) was used to measure the densities of subcritical and supercritical propane (between 35 C and 97 C) and supercritical carbon dioxide (between 32 C and 50 C) saturating hydrophobic silica aerogel (0.2 g/cm3, 90% porosity) synthesized inside Hastelloy U-tubes. Additionally, excess adsorption isotherms for supercritical CO2 and the same porous solid were measured gravimetrically using a precise magnetically-coupled microbalance. Pore fluid densities and total adsorption isotherms increased monotonically with increasing density of the bulk fluid, in contrast to excess adsorption isotherms, which reached a maximum at a subcritical density of the bulk fluid, and then decreased towards zero or negative values at supercritical densities. Compression of the confined fluid significantly beyond the density of the bulk liquid at the same temperature was observed at subcritical temperatures. The features of the isotherms of confined fluid density are interpreted to elucidate the observed behavior of excess adsorption. The maxima of excess adsorption were found to occur below the critical density of the bulk fluid at the conditions corresponding to the beginning of the plateau of total adsorption, marking the end of the transition of pore fluid to a denser, liquid-like pore phase. The results for propane and carbon dioxide showed similarity in the sense of the principle of corresponding states. No measurable effect of pore confinement on the liquid-vapor critical point was found. Quantitative agreement was obtained between excess adsorption isotherms determined from VTD total adsorption results and those measured gravimetrically at the same temperature, confirming the validity of the vibrating tube measurements. Vibrating tube densimetry was demonstrated as a novel experimental approach capable of providing the average density of pore-confined fluids.
Final Report: Guided Acoustic Wave Monitoring of Corrosion in Recovery Boiler Tubing
Chinn, D J; Quarry, M J; Rose, J L
Corrosion of tubing used in black-liquor recovery boilers is a major concern in all pulp and paper mills. Extensive corrosion in recovery boiler tubes can result in a significant safety and environmental hazard. Considerable plant resources are expended to inspect recovery boiler tubing. Currently, visual and ultrasonic inspections are primarily used during the annual maintenance shutdown to monitor corrosion rates and cracking of tubing. This Department of Energy, Office of Industrial Technologies project is developing guided acoustic waves for use on recovery boiler tubing. The feature of this acoustic technique is its cost-effectiveness in inspecting long lengths of tubes from a single inspection point. A piezoelectric or electromagnetic transducer induces guided waves into the tubes. The transducer detects fireside defects from the cold side or fireside of the tube. Cracking and thinning on recovery boiler tubes have been detected with this technique in both laboratory and field applications. This technique appears very promising for recovery boiler tube application, potentially expediting annual inspection of tube integrity.
Tube vibration in industrial size test heat exchanger (30/sup 0/ triangular layout - six crosspass configuration)
Wambsganss, M.W.; Halle, H.; Lawrence, W.P.
Tube vibrations in heat exchangers are being systematically studied in a series of tests performed with an industrial-size test exchanger. Results from flow tests of nine different tube bundles, in a basic 5-baffle, 6-crosspass configuration on a 30/sup 0/-triangular layout with a pitch-to-diameter ratio of 1.25, are reported. the test cases include a full tube bundle, no-tubes-in-window bundle, finned tube bundle, and several proposed field fixes. The testing focused on identification of the lowest critical flowrate to initiate fluidelastic instability (large amplitude tube motion) and the location within the bundle of the tubes which first experience instability. The threshold flowrates are determined from a combination of methods based on sensory observations, vibration amplitude data, and frequency response information. Pressure drop data are also generated and reported.
The influence of multiple tubes on the tube-to-bed heat transfer in a fluidised bed L.M. Armstrong, S. Gu
The influence of multiple tubes on the tube-to-bed heat transfer in a fluidised bed L.M. Armstrong Keywords: CFD Heat transfer Fluidised bed Eulerian a b s t r a c t There have been few studies modelling both flow and heat transfer in fluidised beds. The kinetic theory of granular flow (KTGF) has been used
Incidence of Dental Caries in Tube-Fed Children and Tube-fed Children Receiving Oral Feeding Therapy: A Retrospective Analysis
Morgan, Benjamin P
69-70. 25. Blackman JA, Nelson CL. Reinstituting oral feedings in children fed by gastrostomy tube. Clin Pediatr (Phila) 1985;24(8):434-8. 26. Schauster H. Transition from Tube Feedings to Feedings by Mouth in Children Preventing Eating...
Advanced Mud System for Microhole Coiled Tubing Drilling
Kenneth Oglesby
An advanced mud system was designed and key components were built that augment a coiled tubing drilling (CTD) rig that is designed specifically to drill microholes (less than 4-inch diameter) with advanced drilling techniques. The mud system was tailored to the hydraulics of the hole geometries and rig characteristics required for microholes and is capable of mixing and circulating mud and removing solids while being self contained and having zero discharge capability. Key components of this system are two modified triplex mud pumps (High Pressure Slurry Pumps) for advanced Abrasive Slurry Jetting (ASJ) and a modified Gas-Liquid-Solid (GLS) Separator for well control, flow return and initial processing. The system developed also includes an additional component of an advanced version of ASJ which allows cutting through most all materials encountered in oil and gas wells including steel, cement, and all rock types. It includes new fluids and new ASJ nozzles. The jetting mechanism does not require rotation of the bottom hole assembly or drill string, which is essential for use with Coiled Tubing (CT). It also has low reactive forces acting on the CT and generates cuttings small enough to be easily cleaned from the well bore, which is important in horizontal drilling. These cutting and mud processing components and capabilities compliment the concepts put forth by DOE for microhole coiled tubing drilling (MHTCTD) and should help insure the reality of drilling small diameter holes quickly and inexpensively with a minimal environmental footprint and that is efficient, compact and portable. Other components (site liners, sump and transfer pumps, stacked shakers, filter membranes, etc.. ) of the overall mud system were identified as readily available in industry and will not be purchased until we are ready to drill a specific well.
Particle seeding flow system for horizontal shock tube
Johnston, Stephen [Los Alamos National Laboratory; Garcia, Nicolas J. [Los Alamos National Laboratory; Martinez, Adam A. [Los Alamos National Laboratory; Orlicz, Gregory C. [Los Alamos National Laboratory; Prestridge, Katherine P. [Los Alamos National Laboratory
The Extreme Fluids Team in P-23, Physics Division, studies fluid dynamics at high speeds using high resolution diagnostics. The unsteady forces on a particle driven by a shock wave are not well understood, and they are difficult to model. A horizontal shock tube (HST) is being modified to collect data about the behavior of particles accelerated by shocks. The HST has been used previously for studies of Richtmyer-Meshkov instability using Planar Laser-Induced Fluorescence (PLIF) as well as Particle Image Velocimetry (PIV), diagnostics that measure density and velocity. The purpose of our project is to design a flow system that will introduce particles into the HST. The requirements for this particle flow system (PFS) are that it be non-intrusive, be able to introduce either solid or liquid particles, have an exhaust capability, not interfere with existing diagnostics, and couple with the existing HST components. In addition, the particles must flow through the tube in a uniform way. We met these design criteria by first drawing the existing shock tube and diagnostics and doing an initial design of the ducts for the PFS. We then estimated the losses through the particle flow system from friction and researched possible fans that could be used to drive the particles. Finally, the most challenging component of the design was the coupling to the HST. If we used large inlets, the shock would lose strength as it passed by the inlet, so we designed a novel coupling inlet and outlet that minimize the losses to the shock wave. Our design was reviewed by the Extreme Fluids Team, and it is now being manufactured and built based upon our technical drawings.
Experimental Analysis of the Single-Phase Heat Transfer and Friction Factor inside the Horizontal Internally Micro-Fin Tube
Ghajar, Afshin J.
; micro-fin tube I. INTRODUCTION Single-phase liquid flow in internally enhanced tubes is becoming more of tube is widely used in high flow rate applications because the heat transfer enhancement in high flow that the secondary flow inside the tube with longitudinal fins was insignificant in the laminar flow and the thermal
Uranium Neutron Coincidence Collar Model Utilizing Boron-10 Lined Tubes
Rogers, Jeremy L.; Ely, James H.; Kouzes, Richard T.; Lintereur, Azaree T.; Siciliano, Edward R.
The Department of Energy Office of Nuclear Safeguards and Security (NA-241) is supporting the project Coincidence Counting With Boron-Based Alternative Neutron Detection Technology at Pacific Northwest National Laboratory (PNNL) for the development of a 3He proportional counter alternative neutron coincidence counter. The goal of this project is to design, build and demonstrate a system based upon 10B-lined proportional tubes in a configuration typical for 3He-based coincidence counter applications. This report, providing results for model development of Alternative Boron-Based Uranium Neutron Coincidence Collar (ABUNCL) designs, is a deliverable under Task 2 of the project.
Automatic Tube Cleaning Systems for Condensers & Heat Exchangers
Someah, K.
.0001 h'ft .0F/Btu in the condenser-tube fouling thermal resistance causes a corresponding increase of 1.1% in the compressor power requirement (2). A significant factor affecting the heat transfer capability of water-cooled condensers and heat... available space - that is, the length of piping The operation of rubber balt cleaning for the strainer section. The strainer spool with systems is based on the circulation of a single screen will occupy twice the pipe length. elastomeric, slightly...
Composite Tube Trailer Design/Manufacturing Needs | Department of Energy
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: Theof"Wave the WhiteNational|ofSeptember 3, 2013Composite Tube Trailer
Short-Pulse Beam Transport Tube - Laboratory for Laser Energetics
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItemResearch > TheNuclearHomelandMultivariate Metal-OrganicPulse Beam Transport Tube -
DOE - Office of Legacy Management -- Wolverine Tube Division - MI 05
Office of Legacy Management (LM)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA group currentBradleyTableSelling Corp -KWatertown Arsenal -Center -Wolverine Tube
Flow visualization using momentum and energy transport tubes and applications to turbulent flow in wind farms
Meyers, Johan
As a generalization of the mass-flux based classical stream-tube, the concept of momentum and energy transport tubes is discussed as a flow visualization tool. These transport tubes have the property, respectively, that no fluxes of momentum or energy exist over their respective tube mantles. As an example application using data from large-eddy simulation, such tubes are visualized for the mean-flow structure of turbulent flow in large wind farms, in fully developed wind-turbine-array boundary layers. The three-dimensional organization of energy transport tubes changes considerably when turbine spacings are varied, enabling the visualization of the path taken by the kinetic energy flux that is ultimately available at any given turbine within the array.
Retention sleeve for a thermal medium carrying tube in a gas turbine
Lathrop, Norman Douglas (Ballston Lake, NY); Czachor, Robert Paul (Cincinnati, OH)
Multiple tubes are connected to steam supply and spent cooling steam return manifolds for supplying cooling steam to buckets and returning spent cooling steam from the buckets to the manifolds, respectively. The tubes are prevented from axial movement in one direction by flanges engaging end faces of the spacer between the first and second-stage wheels. Retention sleeves are disposed about cantilevered ends of the tubes. One end of the retention sleeve engages an enlarged flange on the tube, while an opposite end is spaced axially from an end face of the adjoining wheel, forming a gap, enabling thermal expansion of the tubes and limiting axial displacement of the tube in the opposite direction.
Microhole High-Pressure Jet Drill for Coiled Tubing
Ken Theimer; Jack Kolle
Tempress Small Mechanically-Assisted High-Pressure Waterjet Drilling Tool project centered on the development of a downhole intensifier (DHI) to boost the hydraulic pressure available from conventional coiled tubing to the level required for high-pressure jet erosion of rock. We reviewed two techniques for implementing this technology (1) pure high-pressure jet drilling and (2) mechanically-assisted jet drilling. Due to the difficulties associated with modifying a downhole motor for mechanically-assisted jet drilling, it was determined that the pure high-pressure jet drilling tool was the best candidate for development and commercialization. It was also determined that this tool needs to run on commingled nitrogen and water to provide adequate downhole differential pressure and to facilitate controlled pressure drilling and descaling applications in low pressure wells. The resulting Microhole jet drilling bottomhole assembly (BHA) drills a 3.625-inch diameter hole with 2-inch coil tubing. The BHA consists of a self-rotating multi-nozzle drilling head, a high-pressure rotary seal/bearing section, an intensifier and a gas separator. Commingled nitrogen and water are separated into two streams in the gas separator. The water stream is pressurized to 3 times the inlet pressure by the downhole intensifier and discharged through nozzles in the drilling head. The energy in the gas-rich stream is used to power the intensifier. Gas-rich exhaust from the intensifier is conducted to the nozzle head where it is used to shroud the jets, increasing their effective range. The prototype BHA was tested at operational pressures and flows in a test chamber and on the end of conventional coiled tubing in a test well. During instrumented runs at downhole conditions, the BHA developed downhole differential pressures of 74 MPa (11,000 psi, median) and 90 MPa (13,000 psi, peaks). The median output differential pressure was nearly 3 times the input differential pressure available from the coiled tubing. In a chamber test, the BHA delivered up to 50 kW (67 hhp) hydraulic power. The tool drilled uncertified class-G cement samples cast into casing at a rate of 0.04 to 0.17 m/min (8 to 33 ft/hr), within the range projected for this tool but slower than a conventional PDM. While the tool met most of the performance goals, reliability requires further improvement. It will be difficult for this tool, as currently configured, to compete with conventional positive displacement downhole motors for most coil tubing drill applications. Mechanical cutters on the rotating nozzle head would improve cutting. This tool can be easily adapted for well descaling operations. A variant of the Microhole jet drilling gas separator was further developed for use with positive displacement downhole motors (PDM) operating on commingled nitrogen and water. A fit-for-purpose motor gas separator was designed and yard tested within the Microhole program. Four commercial units of that design are currently involved in a 10-well field demonstration with Baker Oil Tools in Wyoming. Initial results indicate that the motor gas separators provide significant benefit.
Numerical Study on Behavior of Hydrogen Ice Pellet in Drift Tube
Yokomine, Takehiko [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University (Japan); Yonemoto, Yukihiro [Hitachi Industries Co. Ltd. (Japan); Ebara, Shinji [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University (Japan); Shimizu, Akihiko [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University (Japan)
Pellet injection with a bent drift tube is considered as one of the flexible methods to have a variety of fueling locations and injection angles in fusion plasma. Since both pellet mass and velocity greatly affect the plasma properties, mass loss and velocity attenuation of the pellet in the drift tube should be evaluated properly. We focused on the impact of the pellet on the tube wall and numerically estimated the mass loss and the velocity attenuation.
Synchrotron radiation and beam tube vacuum in a Very Large Hadron Collider; Stage 1 VLHC
Pivi, M.; Turner, W.C.
Synchrotron Radiation and Beam Tube Vacuum in a Very Large94720 Abstract Synchrotron radiation induced photodesorptionvacuum. The synchrotron radiation power in the Stage 1 VLHC,
Thermal stress analysis of eccentric tube receiver using concentrated solar radiation
Wang, Fuqiang; Shuai, Yong; Yuan, Yuan; Yang, Guo; Tan, Heping [School of Energy Science and Engineering, Harbin Institute of Technology, 92, West Dazhi Street, Harbin 150001 (China)
In the parabolic trough concentrator with tube receiver system, the heat transfer fluid flowing through the tube receiver can induce high thermal stress and deflection. In this study, the eccentric tube receiver is introduced with the aim to reduce the thermal stresses of tube receiver. The ray-thermal-structural sequential coupled numerical analyses are adopted to obtain the concentrated heat flux distributions, temperature distributions and thermal stress fields of both the eccentric and concentric tube receivers. During the sequential coupled numerical analyses, the concentrated heat flux distribution on the bottom half periphery of tube receiver is obtained by Monte-Carlo ray tracing method, and the fitting function method is introduced for the calculated heat flux distribution transformation from the Monte-Carlo ray tracing model to the CFD analysis model. The temperature distributions and thermal stress fields are obtained by the CFD and FEA analyses, respectively. The effects of eccentricity and oriented angle variation on the thermal stresses of eccentric tube receiver are also investigated. It is recommended to adopt the eccentric tube receiver with optimum eccentricity and 90 oriented angle as tube receiver for the parabolic trough concentrator system to reduce the thermal stresses. (author)
Text-Alternative Version: CALiPER: Troffers, Kits, and Tubes Webcast
Broader source: Energy.gov [DOE]
Below is the text-alternative version of the "CALiPER: Troffers, Kits, and Tubes" webcast, held June 20, 2013.
Riemannian geometry of twisted magnetic flux tubes in almost helical plasma flows
Garcia de Andrade, L.C. [Departamento de Fisica Teorica, Instituto de Fisica-UERJ Rua Sao Fco. Xavier 524, Rio de Janeiro, RJ Maracana, CEP:20550-003 (Brazil)
Riemannian geometry of curves applied recently by Ricca [Fluid Dyn. Res 36, 319 (2005)] in the case of inflectional disequilibrium of twisted magnetic flux tubes is used here to compute the magnetic helicity force-free field case. Here the application of Lorentz force-free to the magnetic flux tube in tokamaks allows one to obtain an equation that generalizes the cylindrical tokamak equation by a term that contains the curvature of the magnetic flux tube. Another example of the use of the magnetic flux tube is done by taking the electron magnetohydrodynamics (MHD) fluid model (EMHD) of plasma physics that allows one to compute the velocity of the fluid in helical and almost helical flows in terms of the Frenet torsion of thin magnetic flux tubes. The cases of straight and curved twisted tubes are examined. Second-order effects on the Frenet torsion arise on the poloidal component of the magnetic field, while curvature effects appear in the toroidal component. The magnetic fields are computed in terms of the penetration depth used in superconductors. The ratio between poloidal and toroidal components of the magnetic field depends on the torsion and curvature of the magnetic flux tube. It is shown that the rotation of the almost helical plasma flow contributes to the twist of the magnetic flux tube through the total Frenet torsion along the tube.
Tube-wave Seismic Imaging and Monitoring Method for Oil Reservoirs...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Tube-wave Seismic Imaging and Monitoring Method for Oil Reservoirs and Aquifers Lawrence Berkeley National Laboratory Contact LBL About This Technology Real-Time Reservoir...
Air feed tube support system for a solid oxide fuel cell generator
Doshi, Vinod B. (Monroeville, PA); Ruka, Roswell J. (Pittsburgh, PA); Hager, Charles A. (Zelienople, PA)
A solid oxide fuel cell generator (12), containing tubular fuel cells (36) with interior air electrodes (18), where a supporting member (82) containing a plurality of holes (26) supports oxidant feed tubes (51), which pass from an oxidant plenum (52") into the center of the fuel cells, through the holes (26) in the supporting member (82), where a compliant gasket (86) around the top of the oxidant feed tubes and on top (28) of the supporting member (82) helps support the oxidant feed tubes and center them within the fuel cells, and loosen the tolerance for centering the air feed tubes.
Structural Integrity Assessment of Steam Generator Tubes Using a New EPRI Statistical Approach
Jesus Miranda, Carlos Alexandre de; Mattar Neto, Miguel [IPEN-CNEN/SP, inst. pesquisas energeticas nucleares, 05499 Sao Paulo (Brazil)
A fundamental step in tube plugging management of a Steam Generator (SG), in a Nuclear Power Plant (NPP), is the tube structural integrity evaluation. The degradation of SG tubes may be considered one of the most serious problems found in PWRs operation, mainly when the tube material is the Inconel 600. The first repair criterion was based on the degradation mode where a uniform tube wall thickness corrosion thinning occurred. Thus, a requirement of a maximum depth of 40% of the tube wall thickness was imposed for any type of tube damage. A new approach considers different defects arising from different degradation modes, which comes from the in-service inspections (NDE) and how to consider the involved uncertainties. It is based on experimental results, using statistics to consider the involved uncertainties, to assess structural limits of PWR SG tubes. In any case, the obtained results, critical defect dimensions, are within the regulatory limits. In this paper this new approach will be discussed and it will be applied to two cases (two defects) using typical data of SG tubes of one Westinghouse NPP. The obtained results are compared with 'historical' approaches and some comments are addressed from the results and their comparison. (authors)
Investigation of a steam generator tube rupture sequence using VICTORIA
Bixler, N.E.; Erickson, C.M. [Sandia National Labs., Albuquerque, NM (United States); Schaperow, J.H. [Nuclear Regulatory Commission, Washington, DC (United States)
VICTORIA-92 is a mechanistic computer code for analyzing fission product behavior within the reactor coolant system (RCS) during a severe reactor accident. It provides detailed predictions of the release of radionuclides and nonradioactive materials from the core and transport of these materials within the RCS. The modeling accounts for the chemical and aerosol processes that affect radionuclide behavior. Coupling of detailed chemistry and aerosol packages is a unique feature of VICTORIA; it allows exploration of phenomena involving deposition, revaporization, and re-entrainment that cannot be resolved with other codes. The purpose of this work is to determine the attenuation of fission products in the RCS and on the secondary side of the steam generator in an accident initiated by a steam generator tube rupture (SGTR). As a class, bypass sequences have been identified in NUREG-1150 as being risk dominant for the Surry and Sequoyah pressurized water reactor (PWR) plants.
An Advanced simulation Code for Modeling Inductive Output Tubes
Thuc Bui; R. Lawrence Ives
During the Phase I program, CCR completed several major building blocks for a 3D large signal, inductive output tube (IOT) code using modern computer language and programming techniques. These included a 3D, Helmholtz, time-harmonic, field solver with a fully functional graphical user interface (GUI), automeshing and adaptivity. Other building blocks included the improved electrostatic Poisson solver with temporal boundary conditions to provide temporal fields for the time-stepping particle pusher as well as the self electric field caused by time-varying space charge. The magnetostatic field solver was also updated to solve for the self magnetic field caused by time changing current density in the output cavity gap. The goal function to optimize an IOT cavity was also formulated, and the optimization methodologies were investigated.
Measurement reports for the cryogenically-cooled drift tube quadrupoles
This compilation contains quadrupole measurement reports for LANL type A and type E drift tube cryoquads. The cryoquad information gives s/n, vendor, field strength, phase, b3/b2, b4/b2, b5/b2, b6/b2, center wire location. The measurements for the harmonic measuring system gives time and date of measurements, magnet p/n, coil p/n, coil radii, coil turns, low and high gain, and temperature. Quadrupole information includes effective B` X L, and magnetic center. Bucked and unbucked calculations give signal in {mu}V{center_dot}sec, field in Tesla{center_dot}meter, B(n)/B(2), absolute and relative phase.
Field Demonstraton of Existing Microhole Coiled Tubing Rig (MCTR) Technology
Kent Perry; Samih Batarseh; Sheriff Gowelly; Thomas Hayes
The performance of an advanced Microhole Coiled Tubing Rig (MCTR) has been measured in the field during the drilling of 25 test wells in the Niobrara formation of Western Kansas and Eastern Colorado. The coiled tubing (CT) rig designed, built and operated by Advanced Drilling Technologies (ADT), was documented in its performance by GTI staff in the course of drilling wells ranging in depth from 500 to nearly 3,000 feet. Access to well sites in the Niobrara for documenting CT rig performance was provided by Rosewood Resources of Arlington, VA. The ADT CT rig was selected for field performance evaluation because it is one of the most advanced commercial CT rig designs that demonstrate a high degree of process integration and ease of set-up and operation. Employing an information collection protocol, data was collected from the ADT CT rig during 25 drilling events that encompassed a wide range of depths and drilling conditions in the Niobrara. Information collected included time-function data, selected parametric information indicating CT rig operational conditions, staffing levels, and field observations of the CT rig in each phase of operation, from rig up to rig down. The data obtained in this field evaluation indicates that the ADT CT rig exhibited excellent performance in the drilling and completion of more than 25 wells in the Niobrara under varied drilling depths and formation conditions. In the majority of the 25 project well drilling events, ROP values ranged between 300 and 620 feet per hour. For all but the lowest 2 wells, ROP values averaged approximately 400 feet per hour, representing an excellent drilling capability. Most wells of depths between 500 and 2,000 feet were drilled at a total functional rig time of less than 16 hours; for wells as deep at 2,500 to 3,000 feet, the total rig time for the CT unit is usually well under one day. About 40-55 percent of the functional rig time is divided evenly between drilling and casing/cementing. The balance of time is divided among the remaining four functions of rig up/rig down, logging, lay down bottomhole assembly, and pick up bottomhole assembly. Observations made during all phases of CT rig operation at each of the project well installations have verified a number of characteristics of the technology that represent advantages that can produce significant savings of 25-35 percent per well. Attributes of the CT rig performance include: (1) Excellent hole quality with hole deviation amounting to 1-2 degrees; (2) Reduced need for auxiliary equipment; (3) Efficient rig mobilization requiring only four trailers; (4) Capability of ''Zero Discharge'' operation; (5) Improved safety; and, (6) Measurement while drilling capability. In addition, commercial cost data indicates that the CT rig reduces drilling costs by 25 to 35% compared to conventional drilling technology. Widespread commercial use of the Microhole Coiled Tubing technology in the United States for onshore Lower-48 drilling has the potential of achieving substantially positive impacts in terms of savings to the industry and resource expansion. Successfully commercialized Microhole CT Rig Technology is projected to achieve cumulative savings in Lower-48 onshore drilling expenditures of approximately 6.8 billion dollars by 2025. The reduced cost of CT microhole drilling is projected to enable the development of gas resources that would not have been economic with conventional methods. Because of the reduced cost of drilling achieved with CT rig technology, it is estimated that an additional 22 Tcf of gas resource will become economic to develop. In the future, the Microhole Coiled Tubing Rig represents an important platform for the continued improvement of drilling that draws on a new generation of various technologies to achieve goals of improved drilling cost and reduced impact to the environment.
Superconducting and Spinning Non-Abelian Flux Tubes
Y. Brihaye; Y. Verbin
We find new non-Abelian flux tube solutions in a model of $N_f$ scalar fields in the fundamental representation of SU(N)xU(1) with $N \\leq N_f$ (the ``extended non-Abelian Higgs model''), and study their main properties. Among the solutions there are spinning strings as well as superconducting ones. The solutions exist only in a non trivial domain of the parameter space defined by the ratio between the SU(N) and U(1) coupling constants, the scalar self-interaction coupling constants, the magnetic fluxes (Abelian as well as non-Abelian) and the ``twist parameter'' which is a non-trivial relative phase of the Higgs fields.
Suction recirculation and its effects upon axial-flow pump power consumption
Prince, Tony M.
strainer containing a metal screen cartridge is installed and acts as a water filter. Two gate valves are placed at the suction and the discharge and are used to throttle the flow. Two tubular flow straighteners, made of 1/2 inch diameter copper tubings...
A Numerical Estimate of Flexible Short-tube Flow and Deformation with R-134a and R-410a
Bassiouny, R.; O'Neal, D.
440 �2008 ASHRAE ABSTRACT A finite element model was used to estimate the refrigerant flow through flexible short-tubes for two refrigerants and three moduli of elasticity. The short-tubes were 14.5 mm (0.57 in.) in length with an inlet diameter...-diverg- ing nozzle. A chamfered-like shape was seen at both the inlet and outlet of the short-tube. This shape reduced the large pres- sure drop at the vena contracta downstream of the tube inlet found in rigid short-tubes. However, flexible short-tubes showed...
Effects of Radiative Diffusion on Thin Flux Tubes in Turbulent Solar-like Convection
Weber, Maria A
We study the combined effects of convection and radiative diffusion on the evolution of thin magnetic flux tubes in the solar interior. Radiative diffusion is the primary supplier of heat to convective motions in the lower convection zone, and it results in a heat input per unit volume of magnetic flux tubes that has been ignored by many previous thin flux tube studies. We use a thin flux tube model subject to convection taken from a rotating spherical shell of turbulent, solar-like convection as described by Weber, Fan, and Miesch (2011, Astrophys. J., 741, 11; 2013, Solar Phys., 287, 239), now taking into account the influence of radiative heating on flux tubes of large-scale active regions. Our simulations show that flux tubes of less than or equal to 60 kG subject to solar-like convective flows do not anchor in the overshoot region, but rather drift upward due to the increased buoyancy of the flux tube earlier in its evolution as a result of the inclusion of radiative diffusion. Flux tubes of magnetic fie...
Radiative Heating and the Buoyant Rise of Magnetic Flux Tubes in the Solar Interior
California at Berkeley, University of
Radiative Heating and the Buoyant Rise of Magnetic Flux Tubes in the Solar Interior Y. Fan National the e ect of radiative heating on the evolution of thin magnetic ux tubes in the solar interior Solar Observatoryy, 950 N. Cherry Ave., Tucson, AZ 85719. G. H. Fisher Space Sciences Laboratory, Univ
Congrs Franais de Mcanique Besanon, 29 aot au 2 septembre 2011 Laminage de tubes ODS
Paris-Sud XI, Universit� de
20�me Congr�s Fran�ais de M�canique Besan�on, 29 ao�t au 2 septembre 2011 1 Laminage de tubes ODS K travail porte sur la mise en oeuvre de proc�d� de fabrication de tubes pour des nuances ODS par laminage � ODS � l'�chelle de laboratoire puis � l'�chelle industrielle, nous traiterons du choix des lois de
Fracture analysis of axially cracked pressure tube of pressurized heavy water reactor
Krishnan, S.; Bhasin, V.; Mahajan, S.C. [Bhabha Atomic Research Centre, Bombay (India)] [and others
Three Dimensional (313) finite element elastic plastic fracture analysis was done for through wall axially cracked thin pressure tubes of 220 MWe Indian Pressurized Heavy Water Reactor. The analysis was done for Zr-2 and Zr-2.5Nb pressure tubes operating at 300{degrees}C and subjected to 9.5 Mpa internal pressure. Critical crack length was determined based on tearing instability concept. The analysis included the effect of crack face pressure due to the leaking fluid from tube. This effect was found to be significant for pressure tubes. The available formulae for calculating J (for axially cracked tubes) do not take into account the effect of crack face pressure. 3D finite element analysis also gives insight into variation of J across the thickness of pressure tube. It was observed that J is highest at the mid-surface of tube. The results have been presented in the form of across the thickness average J value and a peak factor on J. Peak factor on J is ratio of J at mid surface to average J value. Crack opening area for different cracked lengths was calculated from finite element results. The fracture assessment of pressure tubes was also done using Central Electricity Generating Board R-6 method. Ductile tearing was considered.
Field Applications of Concrete-Filled FRP Tubes for Marine Piles
SP�215-9 Field Applications of Concrete-Filled FRP Tubes for Marine Piles by A. Fam. R. Greene. and S. Rizkalla Synopsis: This paper presents eight field applications of an innovative composite pile in marine environments. The pile consists of a concrete-filled circular fiber-reinforced polymer (FRP) tube
An experimental investigation of convection heat transfer to supercritical carbon dioxide in miniature tubes
Zhao, Tianshou
dioxide in heated horizontal and vertical miniature tubes are reported in this paper. Stainless steel horizontal and upward flow was enhanced. The experimental results further indicate that in all the flow transfer to supercritical carbon dioxide in both horizontal and vertical miniature heated tubes. � 2002
Russell, Christopher T.
and Astronomy, University of Iowa, Iowa City, IA 52242, USA ABSTRACT On the initial pass by Io the Galileo that they were depleted in their energy content. These tubes have not been seen on every return to the Io torus balance with neighboring flux tubes in steady state. Figure 1 shows such pressure balance. The magnitude
High amplitude wave propagation in collapsible tubes. II. Forerunners and high amplitude waves
Paris-Sud XI, Université de
773 High amplitude wave propagation in collapsible tubes. II. Forerunners and high amplitude waves that, under certain circumstances, a pressure wave of large amplitude which propagates in a fluid feature of such a shock wave propagation inside an initially collapsed tube is the presence ofwavelets
Collector surface for a microwave tube comprising a carbon-bonded carbon-fiber composite
Lauf, Robert J. (Oak Ridge, TN); McMillan, April D. (Knoxville, TN); Johnson, Arvid C. (Lake in the Hills, IL); Moorhead, Arthur J. (Knoxville, TN)
In a microwave tube, an improved collector surface coating comprises a porous carbon composite material, preferably a carbon-bonded carbon fiber composite having a bulk density less than about 2 g/cc. Installation of the coating is readily adaptable as part of the tube manufacturing process.
Thermomechanical Loading Applied on the Cladding Tube During the Pellet Cladding
Thermomechanical Loading Applied on the Cladding Tube During the Pellet Cladding Mechanical the evolution of the ther- momechanical loading applied on the cladding tube during the Pellet- Cladding fuel pellets [1]. As a conse- quence, the pellets from the surrounding fuel rods expand suddenly, which
Development of a new type shock tube without a diaphragm for gas-dynamic laser research
Boyer, Edmond
tube are shown in Fig.2. The cylinder sections C and D are filled with a higher pressure gas than A to the left side, and this makes the high pressure gas in the driver section flowing into the driven sectionDevelopment of a new type shock tube without a diaphragm for gas-dynamic laser research S.Kugimiya1
Design of Batch Tube Reactor 377 Applied Biochemistry and Biotechnology Vol. 9193, 2001
California at Riverside, University of
Design of Batch Tube Reactor 377 Applied Biochemistry and Biotechnology Vol. 91�93, 2001 Copyright unparalleled environmental, economic, and strategic benefits. However, low-cost, high-yield technologies for varying reaction con- ditions. In this article, heat transfer for batch tubes is analyzed to derive
Sensor-less Vibration Suppression and Scan Compensation for Piezoelectric Tube Nanopositioners
Fleming, Andrew J.
) (b) Fig. 2. (a) Charge driven tube scanner. (b) Voltage equivalent circuit. introduces two simple nonSensor-less Vibration Suppression and Scan Compensation for Piezoelectric Tube Nanopositioners-fabrication. Much research has proceeded with the aim of reducing hysteresis and vibration, the foremost problems
Enhanced shell-and-tube heat eschangers for the power and process industries. Final report
Bergles, A.E.; Jensen, M.K.; Somerscales, E.F.; Curcio, L.A. Jr.; Trewin, R.R.
Single-tube pool boiling tests were performed with saturated pure refrigerants and binary mixtures of refrigerants. Generally, with pure refrigerants, the High Flux surface performed better at the higher heat fluxes compared to the Turbo-B tube, and both enhanced surfaces performed significantly better than smooth surface. In tests of R-11/R-113 mixtures, the enhanced surfaces had much less degradation in heat transfer coefficient due to mixture effects compared to smooth tubes; the largest degradation occurred at a mixture of 25% R-11/75% R-113. Under boiling in saturated aqueous solution of calcium sulfate, with a single tube, effects of fouling were more pronounced at the higher heat fluxes for all surfaces. Two staggered tube bundles were tested with tube pitch-diameter ratios of 1.17 and 1.50. For the pure refrigerant, tests on the smooth-tube bundle indicated that the effects on the heat transfer coefficient of varying mass flux, quality, and tube-bundle geometry were small, except at low heat fluxes. Neither enhanced surface showed any effect with changing mass flux or quality. The binary mixture bundle-boiling tests had results that were very similar to those obtained with the pure refrigerants. When boiling a refrigerant-oil mixture, all three surfaces (smooth, High Flux, and Turbo-B) experienced a degradation in its heat transfer coefficient; no surface studied was found to be immune or vulnerable to the presence of oil than another surface.
Design and analysis of a 5-MW vertical-fluted-tube condenser for geothermal applications
Llewellyn, G.H.
The design and analysis of an industtial-sized vertical-fluted-tube condenser. The condenser is used to condense superheated isobutane vapor discharged from a power turbine in a geothermal test facility operated for the US Department of Energy. The 5-MW condenser has 1150 coolant tubes in a four-pass configuration with a total heat transfer area of 725 m/sup 2/ (7800 ft/sup 2/). The unit is being tested at the Geothermal Components Test Facility in the Imperial Valley of East Mesa, California. The condenser design is based on previous experimental research work done at the Oak Ridge National Laboratory on condensing refrigerants on a wide variety of single vertical tubes. Condensing film coefficients obtained on the high-performance vertical fluted tubes in condensing refrigerants are as much as seven times greater than those obtained with vertical smooth tubes that have the same diameter and length. The overall heat transfer performance expected from the fluted tube condenser is four to five times the heat transfer obtained from the identical units employing smooth tubes. Fluted tube condensers also have other direct applications in the Ocean Thermal Energy Conversion (OTEC) program in condensing ammonia, in the petroleum industry in condensing light hydrocarbons, and in the air conditioning and refrigeration industry in condensing fluorocarbon vapors.
Investigation of pressure drop in capillary tube for mixed refrigerant Joule-Thomson cryocooler
Ardhapurkar, P. M. [Mechanical Engineering Department, Indian Institute of Technology Bombay, Mumbai, MS 400 076 India and S. S. G. M. College of Engineering Shegaon, MS 444 203 (India); Sridharan, Arunkumar; Atrey, M. D. [Mechanical Engineering Department, Indian Institute of Technology Bombay, Mumbai, MS 400 076 (India)
A capillary tube is commonly used in small capacity refrigeration and air-conditioning systems. It is also a preferred expansion device in mixed refrigerant Joule-Thomson (MR J-T) cryocoolers, since it is inexpensive and simple in configuration. However, the flow inside a capillary tube is complex, since flashing process that occurs in case of refrigeration and air-conditioning systems is metastable. A mixture of refrigerants such as nitrogen, methane, ethane, propane and iso-butane expands below its inversion temperature in the capillary tube of MR J-T cryocooler and reaches cryogenic temperature. The mass flow rate of refrigerant mixture circulating through capillary tube depends on the pressure difference across it. There are many empirical correlations which predict pressure drop across the capillary tube. However, they have not been tested for refrigerant mixtures and for operating conditions of the cryocooler. The present paper assesses the existing empirical correlations for predicting overall pressure drop across the capillary tube for the MR J-T cryocooler. The empirical correlations refer to homogeneous as well as separated flow models. Experiments are carried out to measure the overall pressure drop across the capillary tube for the cooler. Three different compositions of refrigerant mixture are used to study the pressure drop variations. The predicted overall pressure drop across the capillary tube is compared with the experimentally obtained value. The predictions obtained using homogeneous model show better match with the experimental results compared to separated flow models.
Collector surface for a microwave tube comprising a carbon-bonded carbon-fiber composite
Lauf, R.J.; McMillan, A.D.; Johnson, A.C.; Moorhead, A.J.
In a microwave tube, an improved collector surface coating comprises a porous carbon composite material, preferably a carbon-bonded carbon fiber composite having a bulk density less than about 2 g/cc. Installation of the coating is readily adaptable as part of the tube manufacturing process. 4 figs.
The effects of sliding pressure operation on utility boiler tube integrity
Dewitt-Dick, D.B.; Wangerin, M.C. [Ashland Chemical Co., Boonton, NJ (United States). Ashland Chemical Co.
Sliding pressure operation is employed by utilities to optimize efficiency during periods of reduced load demand. However, this mode of operation can lead to a deterioration in boiler tube integrity. The various mechanisms involved and their effects on tube integrity are discussed. Case histories are also provided, which illustrate these phenomena.
A theoretical model of film condensation in a bundle of horizontal low finned tubes
Honda, H.; Nozu, S.; Takeda, Y. (Okayama Univ. (Japan))
The previous theoretical model of film condensation on a single horizontal low finned tube is extended to include the effect of condensate inundation. Based on the flow characteristics of condensate on a vertical column of horizontal low finned tubes, two major flow modes, the column mode and the sheet mode, are considered. In the column mode, the surface of the lower tubes is divided into the portion under the condensate column where the condensate flow is affected by the impinging condensate from the upper tubes, and the portion between the condensate columns where the condensate flow is not affected by the impinging condensate. In the sheet mode, the whole tube surface is assumed to be affected by the impinging condensate. Sample calculations for practical conditions show that the effects of the fin spacing and the number of vertical tube rows on the heat transfer performance is significant for R-12, while the effects are small for steam. The predicted value of the heat transfer coefficient for each tube row compares well with available experimental data, including four fluids and five tube bundles.
Shell-side condensation heat transfer of R-134a. Part 1: Finned-tube performance
Huber, J.B.; Rewerts, L.E.; Pate, M.B. [Iowa State Univ., Ames, IA (United States). Dept. of Mechanical Engineering
Shell-side condensation coefficient data are presented for the condensation of refrigerant R-134a on tube bundles constructed from 26-fin-per-inch (fpi) and 40-fpi tubes. The tube bundles tested are five rows wide by five rows deep and have a staggered tube arrangement with a horizontal pitch of 22.2 mm (0.875 in.) and a vertical pitch of 19.1 mm (0.75 in.). The data were obtained at a refrigerant saturation temperature of 35 C (95 F) over a bundle heat flux range of 18,000 to 40,000 W/m{sup 2} (5,700 to 12,700 Btu/[h {center_dot} ft {sup 2}]). Average condensing heat transfer coefficients for the bundle as well as average condensing heat transfer coefficients for the middle tube of each row were calculated. The data show that the 40-fpi tube performs better than the 26-fpi tube. The data also show a marked difference in the row to-row heat transfer coefficient trends between the two tube geometries.
Flow-induced tube vibration thresholds in heat exchangers from shellside water tests
Halle, H.; Chenoweth, J.M.; Wambsganss, M.W.
Typical industrial shell-and-tube heat exchanger configurations are investigated experimentally for the occurrence of potentially damaging tube vibration as a function of flowrate. The effort is part of a program to develop vibration avoidance criteria to be integrated and optimized with the advanced thermal, hydraulic, and mechanical design methods now available. The tests use a 0.6-m (2-ft)-diameter, 3.7-m (12-ft)-long shell containing a removable tube bundle whose components are readily rearranged or replaced. The 15 different full tube bundle configurations tested represent various combinations of parameters: triangular or square tube layout patterns with different orientations to the flow, number of crosspasses, sizes of nozzles, plain or finned tubes. All bundles have 19-mm (0.75-in.)-diameter tubes spaced with a pitch-to-diameter ratio of 1.25. The heat exchanger is tested with waterflow on the shellside to determine a critical threshold, above which a small increase in the flowrate initiates a fluidelastic instability resulting in large amplitude vibration. The test conditions, the critical flowrates, the vibration frequencies, and the locations of the tubes most susceptible to vibration are presented. The given data are used for a comparison with a presently recognized method of vibration prediction and will permit updated evaluations as more advanced methods become available in the future.
Flux tubes as the origin of Net Circular Polarization in Sunspot Penumbrae
J. M. Borrero; L. R. Bellot Rubio; D. A. N. Mueller
We employ a 3-dimensional magnetohydrostatic model of a horizontal flux tube, embedded in a magnetic surrounding atmosphere, to successfully reproduce the azimuthal and center-to-limb variations of the Net Circular Polarization observed in sunspot penumbrae. This success is partly due to the realistic modeling of the interaction between the flux tube and the surrounding magnetic field.
Erosion of heat exchanger tubes in fluidized beds. Annual report, 1990
Johnson, E.K.; Flemmer, R.L.C.
This final report describes the activities of the 3-year project entitled ``Erosion of Heat Exchanger Tubes In Fluidized Beds.`` which was completed at the end of 1990. Project accomplishments include the collection of a substantial body of wear data In a 24in. {times} 24in. fluidized bed, comparative wear results In a 6in. {times} 6in. fluidized bed, the development of a dragometer and the collection of a comprehensive set of drag force data in the 24in. {times} 24in. bed, Fast Fourier Transform (FFT) analysis of bubble probe data to establish dominant bubble frequencies in the 24in. {times} 24in. bed, the use of a heat flux gauge for measurement of heat transfer coefficients in the 24in. {times} 24in. bed and the modeling of the tube wear in the 24in. {times} 24in. bed. Analysis of the wear data from the 24in. square bed indicates that tube wear increases with increase in superficial velocity, and with increase in tube height. The latter effect is a result of the tubes higher up in the bed seeing greater movement of dense phase than tubes lower down In the bed. In addition, tube wear was found to decrease with increase in particle size, for constant superficial velocity. Three models of tube wear were formulated and provided acceptable prediction of wear when compared with the experimental data.
Effects of winglets to augment tube wall heat transfer in louvered fin heat exchangers
Thole, Karen A.
Effects of winglets to augment tube wall heat transfer in louvered fin heat exchangers Paul A transfer along the tube wall of the compact heat exchanger through the use of winglets placed of attack, aspect ratio, direction, and shape, were all evaluated based on heat transfer augmentation
Bond Graph Model of a Vertical U-Tube Steam Condenser Coupled with a Heat Exchanger
Paris-Sud XI, Universit� de
turbines, distillation industries using water as a solvent, etc. System-level modeling of steam condensersBond Graph Model of a Vertical U-Tube Steam Condenser Coupled with a Heat Exchanger K. Medjaher1+ A A simulation model for a vertical U-tube steam condenser in which the condensate is stored at the bottom well
Portals to an Architecture: Design of a temporary structure with paper tube arches Steven J. Preston
Bank, Lawrence C.
2011 Keywords: Architecture Structure Engineering Sculpture Sustainability Paper tubes a b s t r a cPortals to an Architecture: Design of a temporary structure with paper tube arches Steven J t Sustainable recyclable paper and composite materials can be ideal choices for the construction of tempo- rary
Simulation of dynamics-coupling in piezoelectric tube scanners by reduced order finite element analysis
Fleming, Andrew J.
and imperfections during the manufactur- ing process of the tube on the dynamics-coupling-caused errors in openSimulation of dynamics-coupling in piezoelectric tube scanners by reduced order finite element as the compensation of dynamics-coupling effects. The present article gives a detailed description of the fully
Friction and Heat Transfer Characteristics of Silica and CNT Nanofluids in a Tube Flow
Kostic, Milivoje M.
Friction and Heat Transfer Characteristics of Silica and CNT Nanofluids in a Tube Flow MILIVOJE M of nanofluids in tube flow has been developed, instrumented and computerized. It has been calibrated using) nanofluids show peculiar results with substantial friction drag reduction and heat transfer enhancement
for intended deployment in large arrays of dishes, with steam directed to a central large steam turbine powerDYNAMIC SIMULATION OF MONO-TUBE CAVITY RECEIVERS FOR DIRECT STEAM GENERATION Jos� Zapata 1 , John dish has been in operation since 2010 with a mono-tube steam cavity receiver, the SG4 system
Effect of conformations on charge transport in a thin elastic tube
Balakrishnan, Radha
We study the effect of conformations on charge transport in a thin elastic tube. Using the Kirchhoff model for a tube with any given Poisson ratio, cross-sectional shape and intrinsic twist, we obtain a class of exact solutions for its conformation. The tube's torsion is found in terms of its intrinsic twist and its Poisson ratio, while its curvature satisfies a nonlinear differential equation which supports exact {\\it periodic} solutions in the form of Jacobi elliptic functions, which we call {\\it conformon lattice} solutions. These solutions typically describe conformations with loops. Each solution induces a corresponding quantum effective {\\it periodic} potential in the Schr\\"{o}dinger equation for an electron in the tube. The wave function describes the delocalization of the electron along the central axis of the tube. We discuss some possible applications of this novel mechanism of charge transport.
Effect of conformations on charge transport in a thin elastic tube
Radha Balakrishnan; Rossen Dandoloff
We study the effect of conformations on charge transport in a thin elastic tube. Using the Kirchhoff model for a tube with any given Poisson ratio, cross-sectional shape and intrinsic twist, we obtain a class of exact solutions for its conformation. The tube's torsion is found in terms of its intrinsic twist and its Poisson ratio, while its curvature satisfies a nonlinear differential equation which supports exact {\\it periodic} solutions in the form of Jacobi elliptic functions, which we call {\\it conformon lattice} solutions. These solutions typically describe conformations with loops. Each solution induces a corresponding quantum effective {\\it periodic} potential in the Schr\\"{o}dinger equation for an electron in the tube. The wave function describes the delocalization of the electron along the central axis of the tube. We discuss some possible applications of this novel mechanism of charge transport.
Roll Wave Effects on Annular Condensing Heat Transfer in Horizontal PCCS Condenser Tube
Masaya Kondo; Hideo Nakamura; Yoshinari Anoda [Japan Atomic Energy Research Institute, Tokai-mura 319-1195 (Japan); Sadanori Saishu; Hiroyuki Obata; Rumi Shimada [Japan Atomic Power Company (Japan); Shinichi Kawamura [Tokyo Electric Power Company, Incorporated, 1-3, Uchisaiwai-cho 1-chome, Chiyoda-ku, Tokyo, 1008560 (Japan)
A horizontal in-tube condensation heat exchanger is under investigation to be used for a passive containment cooling system (PCCS) of a next generation-type BWR. The flow conditions in the horizontal condenser tube were observed both visually and by local void fraction fluctuation. The observed flow regimes at a rated condition were annular flow at the tube inlet, and turned gradually into wavy flow and smooth stratified flow along the length of the tube. It was found further that frequency of the roll waves that appear on the liquid film in the annular flow is closely related to the measured local condensation heat transfer coefficient. Based on the flow observation, the roll wave frequency and measured condensation heat transfer coefficient, a model is proposed which predicts the condensation heat transfer coefficient particularly for annular flows around the tube inlet region. The proposed heat transfer model predicts well the influences of pressure, local gas-phase velocity and film thickness. (authors)
Steam generator tube integrity program: Annual report, August 1995--September 1996. Volume 2
Diercks, D.R.; Bakhtiari, S.; Kasza, K.E.; Kupperman, D.S.; Majumdar, S.; Park, J.Y.; Shack, W.J. [Argonne National Lab., IL (United States)
This report summarizes work performed by Argonne National Laboratory on the Steam Generator Tube Integrity Program from the inception of the program in August 1995 through September 1996. The program is divided into five tasks: (1) assessment of inspection reliability, (2) research on ISI (inservice-inspection) technology, (3) research on degradation modes and integrity, (4) tube removals from steam generators, and (5) program management. Under Task 1, progress is reported on the preparation of facilities and evaluation of nondestructive evaluation techniques for inspecting a mock-up steam generator for round-robin testing, the development of better ways to correlate failure pressure and leak rate with eddy current (EC) signals, the inspection of sleeved tubes, workshop and training activities, and the evaluation of emerging NDE technology. Results are reported in Task 2 on closed-form solutions and finite-element electromagnetic modeling of EC probe responses for various probe designs and flaw characteristics. In Task 3, facilities are being designed and built for the production of cracked tubes under aggressive and near-prototypical conditions and for the testing of flawed and unflawed tubes under normal operating, accident, and severe-accident conditions. Crack behavior and stability are also being modeled to provide guidance for test facility design, develop an improved understanding of the expected rupture behavior of tubes with circumferential cracks, and predict the behavior of flawed and unflawed tubes under severe accident conditions. Task 4 is concerned with the acquisition of tubes and tube sections from retired steam generators for use in the other research tasks. Progress on the acquisition of tubes from the Salem and McGuire 1 nuclear plants is reported.
Sabau, Adrian S [ORNL] [ORNL; Wright, Ian G. [WrightHT, Inc.] [WrightHT, Inc.; Shingledecker, John P. [Electric Power Research Institute (EPRI)] [Electric Power Research Institute (EPRI); Tortorelli, Peter F [ORNL] [ORNL
A model based on a concept of fraction of exfoliated area as a function of oxide scale strain energy was developed to predict the extent of exfoliation of steam-side scale from boiler tube superheater loops. As compared with the Armitt diagram, which can be used to predict when scale damage and exfoliation would be likely to occur, a fraction of exfoliated area approach provides an estimation of mass of scale released and the fraction of tube likely to be blocked by the exfoliation. This paper show results for the extent of blockage expected in a single bend of a superheater loop was predicted as a function of operating time, bend geometry, and outlet steam temperature under realistic service conditions that include outages. The deposits of exfoliated scale were assumed to be distributed horizontally the tubes bends. Three types of bends were considered: regular bends, short bends, and hairpin bends. The progressive increase in steam and tube temperatures along a single loop of superheater tubing and the ensuing variation of oxide scale thickness are considered. Numerical simulation results for a superheater loop made of TP347H austenitic steel indicated that tube blockage fractions larger than 50% are likely to occur within the first two years of boiler operation (with regularly scheduled outages) for outlet tube temperatures of 540-570oC, which is consistent with practical experience. Higher blockage fractions were predicted for tubes with short bends and hairpin bends than for tubes with regular bends, of length that are larger than five internal tube diameters. Finally, the blockage model presented can be used with some confidence to devise operating schedules for managing the consequences of oxide scale exfoliation based on projections of time to some critical blockage fraction for specific boiler operating conditions.
Testing of a 7-tube palladium membrane reactor for potential use in TEP
Carlson, Bryan J [Los Alamos National Laboratory; Trujillo, Stephen [Los Alamos National Laboratory; Willms, R. Scott [Los Alamos National Laboratory
A Palladium Membrane Reactor (PMR) consists of a palladium/silver membrane permeator filled with catalyst (catalyst may be inside or outside the membrane tubes). The PMR is designed to recover tritium from the methane, water, and other impurities present in fusion reactor effluent. A key feature of a PMR is that the total hydrogen isotope content of a stream is significantly reduced as (1) methane-steam reforming and/or water-gas shift reactions proceed on the catalyst bed and (2) hydrogen isotopes are removed via permeation through the membrane. With a PMR design matched to processing requirements, nearly complete hydrogen isotope removals can be achieved. A 3-tube PMR study was recently completed. From the results presented in this study, it was possible to conclude that a PMR is appropriate for TEP, perforated metal tube protectors function well, platinum on aluminum (PtA) catalyst performs the best, conditioning with air is probably required to properly condition the Pd/Ag tubes, and that CO/CO{sub 2} ratios maybe an indicator of coking. The 3-tube PMR had a permeator membrane area of 0.0247 m{sup 2} and a catalyst volume to membrane area ratio of 4.63 cc/cm{sup 2} (with the catalyst on the outside of the membrane tubes and the catalyst only covering the membrane tube length). A PMR for TEP will require a larger membrane area (perhaps 0.35 m{sup 2}). With this in mind, an intermediate sized PMR was constructed. This PMR has 7 permeator tubes and a total membrane area of 0.0851 m{sup 2}. The catalyst volume to membrane area ratio for the 7-tube PMR was 5.18 cc/cm{sup 2}. The total membrane area of the 7-tube PMR (0.0851 m{sup 2}) is 3.45 times larger than total membrane area of the 3-tube PMR (0.0247 m{sup 2}). The following objectives were identified for the 7-tube PMR tests: (1) Refine test measurements, especially humidity and flow; (2) Refine maintenance procedures for Pd/Ag tube conditioning; (3) Evaluate baseline PMR operating conditions; (4) Determine PMR scaling method; (5) Evaluate PMR with realistic feed compositions; (6) Evaluate PMR performance with varying permeate pressures; (7) Study coking-related issues; and (8) Identify any unexpected behavior that may require further investigation (used to study transient behavior). This report presents the tests results defined by these objectives.
Life Estimation of PWR Steam Generator U-Tubes Subjected to Foreign Object-Induced Fretting Wear
Jo, Jong Chull; Jhung, Myung Jo; Kim, Woong Sik; Kim, Hho Jung [Korea Institute of Nuclear Safety (Korea, Republic of)
This paper presents an approach to the remaining life prediction of steam generator (SG) U-tubes, which are intact initially, subjected to fretting-wear degradation due to the interaction between a vibrating tube and a foreign object in operating nuclear power plants. The operating SG shell-side flow field conditions are obtained from a three-dimensional SG flow calculation using the ATHOS3 code. Modal analyses are performed for the finite element models of U-tubes to get the natural frequency, corresponding mode shape, and participation factor. The wear rate of a U-tube caused by a foreign object is calculated using the Archard formula, and the remaining life of the tube is predicted. Also discussed in this study are the effects of the tube modal characteristics, external flow velocity, and tube internal pressure on the estimated results of the remaining life of the tube.
Revised: 12.23.2013 Bb9 (SP13): Embedding YouTube Videos in Blackboard p. 1 of 5 YouTube is a repository of video content on the Web where instructors may find useful content
Qiu, Weigang
Revised: 12.23.2013 Bb9 (SP13): Embedding YouTube Videos in Blackboard p. 1 of 5 YouTube is a repository of video content on the Web where instructors may find useful content for instructional purposes. If you find a video on YouTube that you would like to include in a Blackboard course site, you can either
Proposal for the award of thin-walled precision aluminium alloy tubes for the Atlas Muon Spectrometer
Proposal for the award of thin-walled precision aluminium alloy tubes for the Atlas Muon Spectrometer
Bound States for Nano-Tubes with a Dislocation
Rainer Hempel; Martin Kohlmann; Marko Stautz; J�rgen Voigt
As a model for an interface in solid state physics, we consider two real-valued potentials $V^{(1)}$ and $V^{(2)}$ on the cylinder or tube $S=\\mathbb R \\times (\\mathbb R/\\mathbb Z)$ where we assume that there exists an interval $(a_0,b_0)$ which is free of spectrum of $-\\Delta+V^{(k)}$ for $k=1,2$. We are then interested in the spectrum of $H_t = -\\Delta + V_t$, for $t \\in \\mathbb R$, where $V_t(x,y) = V^{(1)}(x,y)$, for $x > 0$, and $V_t(x,y) = V^{(2)}(x+t,y)$, for $x < 0$. While the essential spectrum of $H_t$ is independent of $t$, we show that discrete spectrum, related to the interface at $x = 0$, is created in the interval $(a_0, b_0)$ at suitable values of the parameter $t$, provided $-\\Delta + V^{(2)}$ has some essential spectrum in $(-\\infty, a_0]$. We do not require $V^{(1)}$ or $V^{(2)}$ to be periodic. We furthermore show that the discrete eigenvalues of $H_t$ are Lipschitz continuous functions of $t$ if the potential $V^{(2)}$ is locally of bounded variation.
LANSCE Drift Tube Linac Water Control System Refurbishment
Marroquin, Pilar S. [Los Alamos National Laboratory
There are several refurbishment projects underway at the Los Alamos National Laboratory LANSCE linear accelerator. Systems involved are: RF, water cooling, networks, diagnostics, timing, controls, etc. The Drift Tube Linac (DTL) portion of the accelerator consists of four DTL tanks, each with three independent water control systems. The systems are about 40 years old, use outdated and non-replaceable equipment and NIM bin control modules, are beyond their design life and provide unstable temperature control. Insufficient instrumentation and documentation further complicate efforts at maintaining system performance. Detailed design of the replacement cooling systems is currently in progress. Previous design experience on the SNS accelerator water cooling systems will be leveraged, see the SNS DTL FDR. Plans call for replacement of water piping, manifolds, pumps, valves, mix tanks, instrumentation (flow, pressure and temperature) and control system hardware and software. This presentation will focus on the control system design with specific attention on planned use of the National Instruments Compact RIO platform with the Experimental Physics and Industrial Control system (EPICS) software toolkit.
Photomultiplier tube failure under hydrostatic pressure in future neutrino detectors
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Chambliss, K.; Diwan, M.; Simos, N.; Sundaram, S. K.
Failure of photomultiplier tubes (PMTs) under hydrostatic pressure is a concern in neutrino detection, specifically, in the proposed Long-Baseline Neutrino Experiment project. Controlled hydrostatic implosion tests were performed on prototypic PMT bulbs of 10-inch diameter and recorded using high speed filming techniques to capture failures in detail. These high-speed videos were analyzed frame-by-frame in order to identify the origin of a crack, measure the progression of individual crack along the surface of the bulb as it propagates through the glass, and estimate crack velocity. Crack velocity was calculated for each individual crack, and an average velocity was determined for allmore��measurable cracks on each bulb. Overall, 32 cracks were measured in 9 different bulbs tested. Finite element modeling (FEM) of crack formation and growth in prototypic PMT shows stress concentration near the middle section of the PMT bulbs that correlates well with our crack velocity measurements in that section. The FEM model predicts a crack velocity value that is close to the terminal crack velocity reported. Our measurements also reveal significantly reduced crack velocities compared to terminal crack velocities measured in glasses using fracture mechanics testing and reported in literature.��less
Neutron tube design study for boron neutron capture therapy application
Verbeke, J.M.; Lee, Y.; Leung, K.N.; Vujic, J.; Williams, M.D.; Wu, L.K.; Zahir, N.
Radio-frequency (RF) driven ion sources are being developed in Lawrence Berkeley National Laboratory (LBNL) for sealed-accelerator-tube neutron generator application. By using a 5-cm-diameter RF-driven multicusp source H{sup +} yields over 95% have been achieved. These experimental findings will enable one to develop compact neutron generators based on the D-D or D-T fusion reactions. In this new neutron generator, the ion source, the accelerator and the target are all housed in a sealed metal container without external pumping. Recent moderator design simulation studies have shown that 14 MeV neutrons could be moderated to therapeutically useful energy ranges for boron neutron capture therapy (BNCT). The dose near the center of the brain with optimized moderators is about 65% higher than the dose obtained from a typical neutron spectrum produced by the Brookhaven Medical Research Reactor (BMRR), and is comparable to the dose obtained by other accelerator-based neutron sources. With a 120 keV and 1 A deuteron beam, a treatment time of {approx}35 minutes is estimated for BNCT.
Photomultiplier tube failure under hydrostatic pressure in future neutrino detectors
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Chambliss, K. [Alfred Univ., Alfred, NY (United States). Multifunctional Materials Lab, Kazuo Inamori School of Engineering; Diwan, M. [Alfred Univ., Alfred, NY (United States). Multifunctional Materials Lab, Kazuo Inamori School of Engineering; Simos, N. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Sundaram, S. K. [Alfred Univ., Alfred, NY (United States). Brookhaven National Laboratory (BNL), Upton, NY (United States)
Failure of photomultiplier tubes (PMTs) under hydrostatic pressure is a concern in neutrino detection, specifically, in the proposed Long-Baseline Neutrino Experiment project. Controlled hydrostatic implosion tests were performed on prototypic PMT bulbs of 10-inch diameter and recorded using high speed filming techniques to capture failures in detail. These high-speed videos were analyzed frame-by-frame in order to identify the origin of a crack, measure the progression of individual crack along the surface of the bulb as it propagates through the glass, and estimate crack velocity. Crack velocity was calculated for each individual crack, and an average velocity was determined for all measurable cracks on each bulb. Overall, 32 cracks were measured in 9 different bulbs tested. Finite element modeling (FEM) of crack formation and growth in prototypic PMT shows stress concentration near the middle section of the PMT bulbs that correlates well with our crack velocity measurements in that section. The FEM model predicts a crack velocity value that is close to the terminal crack velocity reported. Our measurements also reveal significantly reduced crack velocities compared to terminal crack velocities measured in glasses using fracture mechanics testing and reported in literature.
JAEA Fatigue Analysis of EBR-II Duplex Tubing
J. H. Jackson; D. L. Porter; W. R. Lloyd
This work addresses questions brought up concerning the mechanisms associated with fatigue crack growth retardation and/or arrest within the nickel bond layer in duplex 2� Cr-1Mo steel superheater tubes. Previous work performed at the Idaho National Laboratory (INL) indicated that the nickel bond layer did not function as a crack arrestor during fatigue crack propagation with the exception of one, isolated case involving an exceptionally low fatigue load and a high temperature (400 0C) environment. Since it is atypical for a fatigue crack to propagate from a relatively soft material (the nickel bond layer) to a harder material (the 2� Cr-1Mo steel) there has been speculation that the nickel bond layer was hardened in service. Additionally, there are questions surrounding the nature of the fatigue crack propagation within the nickel bond layer; specifically with regard to the presence of voids seen on micrographs of the bond layer and oxidation within the steel along the edge of the nickel bond layer. There is uncertainty as to the effect of these voids and/or oxide barriers with respect to potential fatigue crack arrest.
Examination of Babcock and Wilcox tubes after exposure in an industrial waste incinerator
Keiser, J.R.; Ferber, M.K.; Longmire, H.F.; Walker, L.R.; Hindman, D.L.
Seven ceramic tubes provided by, and in most cases manufactured by, Babcock and Wilcox were exposed in E. I. DuPont`s Wilmington, Delaware, hazardous waste incinerator. These tubes were subsequently examined at Oak Ridge National Laboratory to determine the effect of exposure on the strength and microstructural integrity of the tube materials. An unexposed tube section of one of the materials was also examined. Evaluation methods included c-ring compression tests, light microscopy, and electron microprobe spectroscopy. The c-ring compression tests revealed a very wide range in the strengths of the materials tested; the strongest was DuPont Lanxide Composites (DLC) silicon carbide particulate-strengthened alumina, and the weakest was the DLC Type B mixed-oxide material. The only material for which data on unexposed samples were available showed lower strength than the exposed material. Microstructural examination of the samples yielded minimal evidence of interaction of most of the tube materials with the components of the environment. Microprobe examination showed some segregation of yttrium in the matrix and along the surface of one of the PRD166/zirconia tubes and limited interaction of the fibers in the same tube with the components of the environment.
Feasibility of cooling positrons via conduction in conductive micro-tubes
Khamehchi, M. A., E-mail: email@example.com; Baker, C. J.; Weber, M. H.; Lynn, K. G., E-mail: firstname.lastname@example.com [Center for Materials Research, Washington State University, Pullman, Washington 99164-2814 (United States)
A first order perturbation with respect to velocity has been employed to find the frictional damping force imposed on a single moving charge inside a conductive cylindrical micro-tube. The tensorial relationship between the force and velocity is derived and numerically estimated. Our results asymptotically match that of a flat geometry presented in the literature. Using the single particle analysis the cooling is formulated for an arbitrary density ensemble. It is shown that no further cooling via conduction occurs in the well-established non-neutral plasma equilibrium state. Also, the cooling rate for a weakly interacting ensemble is estimated. It is shown micro-tubes can be employed to cool down low density positron ensembles and/or to improve the beam emittance. A pack of tens of thousands of individual micro-tubes, each cooling only tens of positrons, is capable of cooling hundreds of thousands of particles in each cooling cycle. For example, with tens of particles per micro-tube in a 5?cm long micro-tube stack with the resistivity of 0.46??m and the tubes of radius 50??m, hundreds of thousands of positrons can be cooled down with a time constant of 103??s in longitudinal and 7??s in perpendicular direction. However, it must be noted that the cooling does not guarantee long term storage of particles in micro-tubes.
A Built for Purpose Micro-Hole Coiled Tubing Rig (MCTR)
Bart Patton
This report will serve as the final report on the work performed from the contract period October 2005 thru April 2007. The project 'A Built for Purpose Microhole Coiled Tubing Rig (MCTR)' purpose was to upgrade an existing state-of-the-art Coiled Tubing Drilling Rig to a Microhole Coiled Tubing Rig (MCTR) capable of meeting the specifications and tasks of the Department of Energy. The individual tasks outlined to meet the Department of Energy's specifications are: (1) Concept and development of lubricator and tool deployment system; (2) Concept and development of process control and data acquisition; (3) Concept and development of safety and efficiency improvements; and (4) Final unit integration and testing. The end result of the MCTR upgrade has produced a unit capable of meeting the following requirements: (1) Capable of handling 1-inch through 2-3/8-inch coiled tubing (Currently dressed for 2-3/8-inch coiled tubing and capable of running up to 3-1/2-inch coiled tubing); (2) Capable of drilling and casing surface, intermediate, production and liner hole intervals; (3) Capable of drilling with coiled tubing and has all controls and installation piping for a top drive; (4) Rig is capable of running 7-5/8-inch range 2 casing; and (5) Capable of drilling 5,000 ft true vertical depth (TVD) and 6,000 ft true measured depth (TMD).
Fabrication of fine-grain tantalum diffusion barrier tube for Nb{sub 3}Sn conductors
Hartwig, K. T.; Balachandran, S.; Mezyenski, R.; Seymour, N. [Department of Mechanical Engineering, Texas A and M University, TX 77843 (United States); Robinson, J.; Barber, R. E. [Shear Form Inc, 207 Dellwood St, Bryan 77801 (United States)
Diffusion barriers used in Nb{sub 3}Sn wire are often fabricated by wrapping Ta sheet into a tube with an overlap seam. A common result of such practice is non-uniform deformation in the Ta sheet as it thins by wire drawing because of non-uniform grain size and texture in the original Ta sheet. Seamless Ta tube with a fine-grain and uniform microstructure would be much better for the diffusion barrier application, but such material is expensive and difficult to manufacture. This report presents results on a new fabrication strategy for Ta tube that shows promise for manufacture of less costly tube with an improved microstructure. The fabrication method begins with seam-welded tube but gives a fine-grain uniform microstructure with little difference between the longitudinal seam weld region and the parent metal after post-weld processing. Severe plastic deformation processing (SPD) applied by area reduction extrusion and tube equal channel angular extrusion (tECAE) are used to refine and homogenize the microstructure. Microstructure and mechanical property results are presented for Ta tubes fabricated by this new processing strategy.
Directly connected heat exchanger tube section and coolant-cooled structure
Chainer, Timothy J; Coico, Patrick A; Graybill, David P; Iyengar, Madhusudan K; Kamath, Vinod; Kochuparambil, Bejoy J; Schmidt, Roger R; Steinke, Mark E
A cooling apparatus for an electronics rack is provided which includes an air-to-liquid heat exchanger, one or more coolant-cooled structures and a tube. The heat exchanger, which is associated with the electronics rack and disposed to cool air passing through the rack, includes a plurality of distinct, coolant-carrying tube sections, each tube section having a coolant inlet and a coolant outlet, one of which is coupled in fluid communication with a coolant loop to facilitate flow of coolant through the tube section. The coolant-cooled structure(s) is in thermal contact with an electronic component(s) of the rack, and facilitates transfer of heat from the component(s) to the coolant. The tube connects in fluid communication one coolant-cooled structure and the other of the coolant inlet or outlet of the one tube section, and facilitates flow of coolant directly between that coolant-carrying tube section of the heat exchanger and the coolant-cooled structure.
Mechanical Design of Steel Tubing for Use in Black Liquor Recovery Boilers
Taljat, B.; Zacharaia, T.; Wang, X.; Kesier, J.; Swindeman, R.; Hubbard, C.
Finite element models were developed for thermal-mechanical analysis of black liquor recovery boiler floor tubes. Residual stresses in boiler floors due to various manufacturing processes were analyzed. The modeling results were verified by X-ray and neutron diffraction measurements at room temperature on as-manufactured tubes as well as tubes after service. The established finite element models were then used to evaluate stress conditions during boiler operation. Using these finite element models, a parametric response surface study was performed to investigate the influence of material properties of the clad layer on stresses in the floor tubes during various boiler operating conditions, which yielded a generalized solution of stresses in the composite tube floors. The results of the study are useful for identifying the mechanisms of cracking experienced by recovery boilers. Based on the results of the response surface study, a recommendation was made for more suitable materials in terms of the analyzed mechanical properties. Alternative materials and manufacturing processes are being considered to improve the resistance to cracking and the in-service life of composite tubes. To avoid numerous FE stress-strain analyses of composite tubes made of different material combinations, a response surface study was performed that considered two essential mechanical properties of the clad material - coefficient of thermal expansion and yield stress - as independent variables. The response surface study provided a generalized solution of stresses in the floor in terms of the two selected parameters.
Experimental and computational modeling of oscillatory flow within a baffled tube containing periodic-tri-orifice baffle geometries
Gomez, Hector
Experimental and computational modeling of oscillatory flow within a baffled tube containing describes numerical simulation and matching experimental results for oscillatory flow within a baffled tube the basic mechanism of OFM in a horizontal single-orifice baffled tube. As the fluid passes through
PATENT/DISCLOSURE LIST (1) A. Bindal, "Sidewall Lithography for Growing Horizontal Carbon Nano Tubes and a
Eirinaki, Magdalini
Tubes and a Process Flow for Complementary Carbon Nano Tube Field Effect Transistor (CCFET) FabricationPATENT/DISCLOSURE LIST (1) A. Bindal, "Sidewall Lithography for Growing Horizontal Carbon Nano for Manufacturing Nano-Interconnects and Catalyst Islands for Growing Carbon Nano Tubes", provisional patent
Composite tube cracking in kraft recovery boilers: A state-of-the-art review
Singbeil, D.L.; Prescott, R. [Pulp and Paper Research Inst. of Canada, Vancouver, British Columbia (Canada); Keiser, J.R.; Swindeman, R.W. [Oak Ridge National Lab., TN (United States)
Beginning in the mid-1960s, increasing energy costs in Finland and Sweden made energy recovery more critical to the cost-effective operation of a kraft pulp mill. Boiler designers responded to this need by raising the steam operating pressure, but almost immediately the wall tubes in these new boilers began to corrode rapidly. Test panels installed in the walls of the most severely corroding boiler identified austenitic stainless steel as sufficiently resistant to the new corrosive conditions, and discussions with Sandvik AB, a Swedish tube manufacturer, led to the suggestion that coextruded tubes be used for water wall service in kraft recovery boilers. Replacement of carbon steel by coextruded tubes has solved most of the corrosion problems experienced by carbon steel wall tubes, however, these tubes have not been problem-free. Beginning in early 1995, a multidisciplinary research program funded by the US Department of Energy was established to investigate the cause of cracking in coextruded tubes and to develop improved materials for use in water walls and floors of kraft recovery boilers. One portion of that program, a state-of-the-art review of public- and private-domain documents related to coextruded tube cracking in kraft recovery boilers is reported here. Sources of information that were consulted for this review include the following: tube manufacturers, boiler manufacturers, public-domain literature, companies operating kraft recovery boilers, consultants and failure analysis laboratories, and failure analyses conducted specifically for this project. Much of the information contained in this report involves cracking problems experienced in recovery boiler floors and those aspects of spout and air-port-opening cracking not readily attributable to thermal fatigue. 61 refs.
Flow distribution analysis on the cooling tube network of ITER thermal shield
Nam, Kwanwoo; Chung, Wooho; Noh, Chang Hyun; Kang, Dong Kwon; Kang, Kyoung-O; Ahn, Hee Jae; Lee, Hyeon Gon [ITER Korea, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of)
Thermal shield (TS) is to be installed between the vacuum vessel or the cryostat and the magnets in ITER tokamak to reduce the thermal radiation load to the magnets operating at 4.2K. The TS is cooled by pressurized helium gas at the inlet temperature of 80K. The cooling tube is welded on the TS panel surface and the composed flow network of the TS cooling tubes is complex. The flow rate in each panel should be matched to the thermal design value for effective radiation shielding. This paper presents one dimensional analysis on the flow distribution of cooling tube network for the ITER TS. The hydraulic cooling tube network is modeled by an electrical analogy. Only the cooling tube on the TS surface and its connecting pipe from the manifold are considered in the analysis model. Considering the frictional factor and the local loss in the cooling tube, the hydraulic resistance is expressed as a linear function with respect to mass flow rate. Sub-circuits in the TS are analyzed separately because each circuit is controlled by its own control valve independently. It is found that flow rates in some panels are insufficient compared with the design values. In order to improve the flow distribution, two kinds of design modifications are proposed. The first one is to connect the tubes of the adjacent panels. This will increase the resistance of the tube on the panel where the flow rate is excessive. The other design suggestion is that an orifice is installed at the exit of tube routing where the flow rate is to be reduced. The analysis for the design suggestions shows that the flow mal-distribution is improved significantly.
Two-Phase Flow of Two HFC Refrigerant Mixtures Through Short Tube Orifices, Draft Final Report�
Payne, W. V.; O'Neal, D. L.
to commercially available short tubes in residential air conditioners or heat pumps. Figure 2.2 shows the schematic of the orifice test section for routine performance tests. The short tube was made from brass which was bored and reamed to insure a smooth...) measurements of the effects of oil concentration on performance. Conditions were chosen to cover a wide range of operating conditions for a short tube expansion device found in a typical residential heat pump or air-conditioner. The experimental variables...
Reactance simulation for the defects in steam generator tube with outside ferrite sludge
Ryu, Kwon-sang; Kima, Yong-il [Division of Metrology for Quality Life, KRISS, Daejeon, 305-600 (Korea, Republic of); Son, Derac [Department of Physics, Hannam University, Daejeon, 336-840 (Korea, Republic of); Park, Duck-gun [Nuclear Material Technique Development Team, KAERI, Daejeon, 305-353 (Korea, Republic of); Jung, Jae-kap [Division of Physical Metrology, KRISS, Daejeon, 305-600 (Korea, Republic of)
A magnetic sludge is partly produced around the tube sheet outside a steam generator due to stress and heat. The sludge with magnetite is one of the important factors affecting eddy current signals. It causes trouble for the safety of the steam generator tubes and is difficult to detect by conventional eddy current methods. A new type of probe is needed to detect the signals for the magnetic sludge. We designed a new U-type yoke which has two kinds of coils--a magnetizing coil and the other a detecting coil--and we simulated the signal induced by the ferromagnetic sludge in the Inconel 600 tube.
Observations of erosion of in-bed tubes in the Great Lakes AFBC
Not Available
Initially, the atmospheric fluidized-bed combustor demonstration plant experienced erosion difficulties with low bed temperature, high heat transfer rates, low combustion efficiencies and high elutriation rates. Some of the blame for these problems was attributed to the bed particle size being finer than originally intended. The vertical surfaces exhibited high wear rates, and several of the tubes were polished with visible signs of wear. These high erosion rates were attributed to the tendency of bubbles rising through the bed to follow preferred paths along the vertical tube surface. One approach being considered to combat this problem is the use of fins transverse to the tube axis to disrupt the bubble flow pattern.
Application of the embedded polariscope photoelastic technique to the stress analysis of flanged tubes
Aiken, William Byron
of the internal stresses as do the previously mentioned methods. Another method which has been successfully used to test flanged tubes is the brittle model technique in which a brittle model is loaded to failure. This method is useful for testing flanged... be used to measure stresses in flanged tubes, flanged tube models of typical and extreme dimen- sions were tested under two extreme conditions of load- ing: (1) zero internal pressure, and (2) zero seal force. In each model, a polariscope was embedded...
Waterproofed Photomultiplier Tube Assemblies for the Daya Bay Reactor Neutrino Experiment
Chow, Ken; Edwards, Emily; Edwards, William; Ely, Ry; Hoff, Matthew; Lebanowski, Logan; Li, Bo; Li, Piyi; Lin, Shih-Kai; Liu, Dawei; Liu, Jinchang; Luk, Kam-Biu; Miao, Jiayuan; Napolitano, Jim; Ochoa-Ricoux, Juan Pedro; Peng, Jen-Chieh; Qi, Ming; Steiner, Herbert; Stoler, Paul; Stuart, Mary; Wang, Lingyu; Yang, Changgen; Zhong, Weili
In the Daya Bay Reactor Neutrino Experiment 960 20-cm-diameter waterproof photomultiplier tubes are used to instrument three water pools as Cherenkov detectors for detecting cosmic-ray muons. Of these 960 photomultiplier tubes, 341 are recycled from the MACRO experiment. A systematic program was undertaken to refurbish them as waterproof assemblies. In the context of passing the water leakage check, a success rate better than 97% was achieved. Details of the design, fabrication, testing, operation, and performance of these waterproofed photomultiplier-tube assemblies are presented.
Utilization of endless coiled tubing and nitrogen gas in geothermal well system maintenance
McReynolds, A.S.; Maxson, H.L.
The use of endless coiled tubing and nitrogen gas combine to offer efficient means of initiating and maintaining geothermal and reinjection well productivity. Routine applications include initial flashing of wells in addition to the surging of the formation by essentially the same means to increase production rates. Various tools can be attached to the tubing for downhole measurement purposes whereby the effectiveness of the tools is enhanced by this method of introduction to the well bore. Remedial work such as scale and fill removal can also be accomplished in an efficient manner by using the tubing as a work string and injecting various chemicals in conjunction with specialized tools to remedy downhole problems.
VFLOW2D - A Vorte-Based Code for Computing Flow Over Elastically Supported Tubes and Tube Arrays
A numerical flow model is developed to simulate two-dimensional fluid flow past immersed, elastically supported tube arrays. This work is motivated by the objective of predicting forces and motion associated with both deep-water drilling and production risers in the oil industry. This work has other engineering applications including simulation of flow past tubular heat exchangers or submarine-towed sensor arrays and the flow about parachute ribbons. In the present work, a vortex method is used for solving the unsteady flow field. This method demonstrates inherent advantages over more conventional grid-based computational fluid dynamics. The vortex method is non-iterative, does not require artificial viscosity for stability, displays minimal numerical diffusion, can easily treat moving boundaries, and allows a greatly reduced computational domain since vorticity occupies only a small fraction of the fluid volume. A gridless approach is used in the flow sufficiently distant from surfaces. A Lagrangian remap scheme is used near surfaces to calculate diffusion and convection of vorticity. A fast multipole technique is utilized for efficient calculation of velocity from the vorticity field. The ability of the method to correctly predict lift and drag forces on simple stationary geometries over a broad range of Reynolds numbers is presented.
Using coiled tubing in HP/HT corrosive gas wells
High-yield-strength (100,000 psi) coiled tubing (CT) material has allowed for CT intervention in Mobile Bay Norphlet completions. These wells are approximately 22,000-ft-vertical-depth, high-pressure, hydrogen sulfide (H{sub 2}S) gas wells. Operations performed on the Norphlet wells include a scale cleanout to approximately 22,000 ft, a hydrochloric acid (HCl) job at 415 F, and buildup removal from a safety valve. The scale cleanout was performed first with a spiral wash tool. The well was killed with 10-lbm/gal sodium bromide (NaBr) brine; the same brine was used for cleanout fluid. Cost savings of 60% were realized. A HCl matrix acid job at 415 F was performed next, followed by a scale cleanout across the downhole safety valve. The safety valve was cleared of debris in 1 operational day. Estimated cost of the CT operation was 5 to 10% less than that of a rig workover. The 100,000-psi-yield Ct material used for the Mobile Bay operations does not comply with the (NACE) Standard MR-0175. But on the basis of extensive laboratory testing by the CT manufacturer, the decision was made that the material would pass a modified test performed with decreased H{sub 2}S levels. A maximum level of 400 ppm H{sub 2}S was determined as the safe working limit. Because the maximum H{sub 2}S content in the wells described later was 120 ppm, the risk of sulfide-stress cracking (SSC) was considered acceptably low. Elevated bottomhole temperatures (BHT`s) increase the corrosion rate of metals exposed to corrosives. Extensive laboratory testing of corrosion inhibitors allowed for design of a matrix-acidizing treatment to remove near-wellbore damage caused by lost zinc bromide (ZnBr) completion brine.
Synthesis and characterization of a novel tube-in-tube nanostructured PPy/MnO{sub 2}/CNTs composite for supercapacitor
Li, Juan, E-mail: firstname.lastname@example.com [College of Chemistry and Chemical Engineering, Xinjiang University, Urumqi 830046 (China) [College of Chemistry and Chemical Engineering, Xinjiang University, Urumqi 830046 (China); Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Que, Tingli [College of Chemistry and Chemical Engineering, Xinjiang University, Urumqi 830046 (China)] [College of Chemistry and Chemical Engineering, Xinjiang University, Urumqi 830046 (China); Huang, Jianbin, E-mail: firstname.lastname@example.com [College of Chemistry and Chemical Engineering, Xinjiang University, Urumqi 830046 (China) [College of Chemistry and Chemical Engineering, Xinjiang University, Urumqi 830046 (China); Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China)
Graphical abstract: A novel tube-in-tube nanostructured PPy/MnO{sub 2}/CNTs composite have been successfully fabricated. Its inner tubules are CNTs and the outer tubules are template-synthesized PPy. Most MnO{sub 2} nanoparticles are sandwiched between the inner and outer wall, some relatively large particles are also latched onto the outside wall of the PPy tube. The composite yields a good electrochemical reversibility through 1000 cycles� cyclic voltammogram (CV) test and galvanostatic charge�discharge experiments at different current densities. Display Omitted Highlights: ? We fabricate a ternary organic�inorganic complex of PPy/MnO{sub 2}/CNTs composite. ? We characterize its morphological structures and properties by several techniques. ? The composite possesses the typical tube-in-tube nanostructures. ? Most MnO{sub 2} nanoparticles are sandwiched between the inner CNTs and outer PPy wall. ? The composite has good electrochemical reversibility for supercapacitor. -- Abstract: Ternary organic�inorganic complex of polypyrrole/manganese dioxide/carbon nanotubes (PPy/MnO{sub 2}/CNTs) composite was prepared by in situ chemical oxidation polymerization of pyrrole in the host of inorganic matrix of MnO{sub 2} and CNTs, using complex of methyl orange (MO)/FeCl{sub 3} was used as a reactive self-degraded soft-template. The morphological structures of the composite were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopic (HRTEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD), respectively. All the results indicate that the PPy/MnO{sub 2}/CNTs composite possesses the typical tube-in-tube nanostructures: the inner tubules are CNTs and the outer tubules are template-synthesized PPy. MnO{sub 2} nanoparticles may either sandwich the space between the inner and outer tubules or directly latch onto the wall of the PPy tubes. The composite yields a good electrochemical reversibility through 1000 cycles� cyclic voltammogram (CV) test in the potential range of ?0.6 to 0.4 V and its specific capacitance was up to 402.7 F g{sup ?1} at a current density of 1 A g{sup ?1} in galvanostatic charge�discharge experiment.
Failure analysis of an {alpha}-SiC tube subjected to thermal cycling in an oxygen-steam atmosphere
Breder, K.; Keiser, J.R.
Failure analysis of a 0.965 m long closed end {alpha}-SiC tube which failed during thermal cycling in an oxygen-steam atmosphere was conducted. The tube failed during heating after having survived several cycles. The shattered tube was re-assembled and the fracture origin was determined to be a flaw in the lower part of the tube on the outer surface. The flaw was likely an oxidation pit produced during the previous cycles. The stresses in the tube at the time of failure were a combination of stresses from the internal pressure and from thermal gradients.
An experimental study of a vertical tube gas-fluidized bed
Mandich, Kevin Matthew
acceleration constant. This fixed bed is illustrated infrom the low-velocity fixed bed to the flat slug regime seenvertical tube such that the fixed bed height lay between the
Supply and demand in the material recovery system for cathode ray tube glass
Nadeau, Marie-Claude
This paper presents an analysis of the material recovery system for leaded glass from cathode ray tubes (CRTs). In particular, the global mass flow of primary and secondary CRT glass and the theoretical capacities for using ...
Commissioning of a Coupled Earth Tube and Natural Ventilation System at the Acceptance Phase
Pan, S.; Zheng, M.; Yoshida, H.
In this paper, the environment and energy performance of an actual coupled earth tube and natural ventilation system in a gymnasium was measured during the acceptance phase in two operation states: no ventilation and natural ventilation. From...
Determination of explosive blast loading equivalencies with an explosively driven shock tube
Jackson, Scott I [Los Alamos National Laboratory; Hill, Larry G [Los Alamos National Laboratory; Morris, John S [Los Alamos National Laboratory
Recently there has been significant interest in evaluating the potential of many different non-ideal energetic materials to cause blast damage. We present a method intended to quantitatively compare the blast loading generated by different energetic materials through use of an explosively driven shock tube. The test explosive is placed at the closed breech end of the tube and initiated with a booster charge. The resulting shock waves are then contained and focused by the tube walls to form a quasi-one-dimensional blast wave. Pressure transducers along the tube wall measure the blast overpressure versus distance from the source and allow the use of the one-dimensional blast scaling relationship to determine the energy deposited into the blast wave per unit mass of test explosive. These values are then compared for different explosives of interest and to other methods of equivalency determination.
Shared Experiences and Collective Production: Note Card Confessions on YouTube
Fowlds, Kelli
New media are continuously changing the way in which youth communicate. Social media and online production, especially, are rapidly evolving. This research analyzes note card confession videos found on the popular video site, YouTube. It looks...
all-glass evacuated tube: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
21 22 23 24 25 Next Page Last Page Topic Index 1 Study on Design of an Evacuated Tube Solar Collector for High Temperature Steam Generation CiteSeer Summary: AbstractThe...
The Characterization and Feasibility of a Low-Duty-Cycle Diaphragmless Shock Tube
Taylor, David Christopher
The feasibility and characterization of a novel diaphragmless shock tube was examined at the National Aerothermochemistry Laboratory at Texas A&M University. The goal was to design a facility that reliably produces shock waves through air in a...
Sensing system for detection and control of deposition on pendant tubes in recovery and power boilers
Kychakoff, George; Afromowitz, Martin A; Hugle, Richard E
A system for detection and control of deposition on pendant tubes in recovery and power boilers includes one or more deposit monitoring sensors operating in infrared regions and about 4 or 8.7 microns and directly producing images of the interior of the boiler. An image pre-processing circuit (95) in which a 2-D image formed by the video data input is captured, and includes a low pass filter for performing noise filtering of said video input. An image segmentation module (105) for separating the image of the recovery boiler interior into background, pendant tubes, and deposition. An image-understanding unit (115) matches derived regions to a 3-D model of said boiler. It derives a 3-D structure the deposition on pendant tubes in the boiler and provides the information about deposits to the plant distributed control system (130) for more efficient operation of the plant pendant tube cleaning and operating systems.
Applications of the Strong Heat Transformation by Pulse Flow in the Shell and Tube Heat Exchanger�
Chen, Y.; Zhao, J.
This article deals with the heat exchange coefficient varied with pulse frequency in the pulsation tube with different flow forms. The findings show that heat can be exchanged coefficient with the pulse frequency, and it has an optimal frequency...
THERMAL-HYDRAULIC STUDIES IN SUPPORT OF THE ARIES-CS T-TUBE DIVERTOR DESIGN S. I. ABDEL-KHALIK,*a L and engineering optimization. This paper focuses on the thermal-hydraulic analyses and experiments performed
Applications of the Strong Heat Transformation by Pulse Flow in the Shell and Tube Heat Exchanger
Chen, Y.; Zhao, J.
This article deals with the heat exchange coefficient varied with pulse frequency in the pulsation tube with different flow forms. The findings show that heat can be exchanged coefficient with the pulse frequency, and it has an optimal frequency...
Flooding Experiments with Steam and Water in a Large Diameter Vertical Tube
Williams, Susan Nicole
of the surge line and steam generator tubes. Currently no satisfactory mechanistic ooding models exist yet, so current safety analysis codes employ empirical correlations to predict ooding. With their default ooding models, the SCDAP/RELAP5, MELCOR and MAAP...
Characterization of an Aerosol Shock Tube Facility for Heterogeneous Combustion Studies
Sandberg, Lori Marie
tube prior to running the experiment. An incident shock wave vaporizes the liquid fuel droplets, then the reflected shock wave initiates ignition of the mixture. This study presents the characterization of an aerosol fuel injection method to the shock...
EA-1131: Relocation of Neutron Tube Target Loading Operation, Los Alamos Laboratory, Los Alamos, New Mexico
Broader source: Energy.gov [DOE]
This EA evaluates the environmental impacts of the proposal to relocate the Neutron Tube Target Loading operations at the U.S. Department of Energy Los Alamos National Laboratory in New Mexico from...
Multi-tube thermal fuse for nozzle protection from a flame holding or flashback event
Lacy, Benjamin Paul; Davis, Jr., Lewis Berkley; Johnson, Thomas Edward; York, William David
A protection system for a pre-mixing apparatus for a turbine engine, includes: a main body having an inlet portion, an outlet portion and an exterior wall that collectively establish a fuel delivery plenum; and a plurality of fuel mixing tubes that extend through at least a portion of the fuel delivery plenum, each of the plurality of fuel mixing tubes including at least one fuel feed opening fluidly connected to the fuel delivery plenum; at least one thermal fuse disposed on an exterior surface of at least one tube, the at least one thermal fuse including a material that will melt upon ignition of fuel within the at least one tube and cause a diversion of fuel from the fuel feed opening to at least one bypass opening. A method and a turbine engine in accordance with the protection system are also provided.
Design of Plate-Fin Tube Dehumidifiers for Humidification-Dehumidification Desalination Systems
Sievers, Martin
A two-dimensional numerical model of a plate-fin tube heat exchanger for use as a dehumidifier in a humidification-dehumidification (HDH) desalination systems is developed, because typical heating, ventilating, and air ...
Conceptual Design of a Large, Passive Pressure-Tube Light Water Reactor
Hejzlar, P.
A design for a large, passive, light water reactor has been developed. The proposed concept is a pressure tube reactor of similar design to CANDU reactors, but differing in three key aspects. First, a solid SiC-coated ...
concepts to the field of high power microwave (HPM) tubes. These concepts are well known to the control systems community, but have not yet been fully exploited within the HPM community. The simpler
Transcriptional analysis of the healing response of wounded nerves treated with collagen and silicone tubes
Wong, Matthew Q
This study examines the transcriptional differences between nerve wounds treated with silicone tubes and those treated with collagen nerve regeneration templates. The primary motivation for the study is to test the hypothesis ...
Keywordscondensation tube, surface modification, waste heat and condensation water recovery system
Leu, Tzong-Shyng "Jeremy"
Keywordscondensation tube, surface modification, waste heat and condensation water recovery techniques is waste heat and condensation water recovery system. Waste heat and condensation water recovery system is one of the most important facilities in power plants. High efficiency waste heat
Generation of Cold Argon Plasma Jet at the End of Flexible Plastic Tube
Kostov, Konstantin G; Prysiazhnyi, Vadym
This brief communication reports a new method for generation of cold atmospheric pressure plasma jet at the downstream end of a flexible plastic tube. The device consists of a small chamber where dielectric barrier discharge (DBD) is ignited in Argon. The discharge is driven by a conventional low frequency AC power supply. The exit of DBD reactor is connected to a commercial flexible plastic tube (up to 4 meters long) with a thin floating Cu wire inside. Under certain conditions an Ar plasma jet can be extracted from the downstream tube end and there is no discharge inside the plastic tube. The jet obtained by this method is cold enough to be put in direct contact with human skin without electric shock and can be used for medical treatment and decontamination.
Fluoroscopically Guided Feeding Tube Insertion for Relief of Postoperative Gastrointestinal Anastomotic Obstruction and Leakage
Han, Young-Min [Chonbuk National University Medical School and Hospital, Department of Radiology (Korea, Republic of)], E-mail: firstname.lastname@example.com; Kim, Chan-Young; Yang, Doo-Hyun [Chonbuk National University Medical School and Hospital, Department of Surgery (Korea, Republic of); Kwak, Hyo-Sung; Jin, Gong-Yong [Chonbuk National University Medical School and Hospital, Department of Radiology (Korea, Republic of)
Purpose. To evaluate the feasibility and effectiveness of feeding tube insertion and enteral feeding for the treatment of postoperative gastrointestinal anastomotic obstruction and leakage. Materials and Methods. From June 1999 to June 2002, thirty-four cases of postoperative gastrointestinal anastomotic obstruction and leakage after surgery for gastric carcinoma were treated by insertion of a feeding tube under fluoroscopic guidance. Twenty-one patients were male and 13 were female. The patients' ages ranged from 39 to 74 years (mean age: 61 years). All the patients experienced vomiting, and 15 patients had anastomotic site or duodenal stump leakage. We evaluated the feasibility of feeding tube insertion for enteral feeding to improve the obstruction and facilitate leakage site closure, and the patients' nutritional benefit was also evaluated by checking the serum albumin level between pre- and post-enteral feeding via the feeding tube.Results. Thirty-two patients (94%) were successfully managed by feeding tube insertion, but the remaining two were not managed, and this was due to severe angulations at the anastomotic site. The procedure times for feeding tube insertion ranged from 15 to 60 minutes (mean time: 45 minutes). Twenty-eight patients experienced symptomatic relief of gastrointestinal obstruction, and they were able to resume a normal regular diet after feeding tube removal. Three patients underwent stent insertion due to recurrent symptoms, and one patient underwent jejunostomy feeding due to the presence of a persistent leakage site. Eleven patients achieved leakage site closure after enteral feeding via a feeding tube. The serum albumin level was significant, increased from pre-enteral feeding (2.65 {+-} 0.37 g/dL) to the post-enteral feeding (3.64 {+-} 0.58 g/dL) via the feeding tube (p < 0.001). The duration of follow-up ranged from one to 53 months (mean: 23 months). Conclusion. The insertion of a feeding tube for enteral feeding under fluoroscopic guidance is safe, and it provides effective relief from gastrointestinal anastomotic site obstruction and leakage after gastric surgery. Moreover, our findings indicate that feeding tube insertion for enteral feeding may be used as the primary procedure to treat postoperative anastomotic obstruction and leakage.
Enhanced tubes for steam condensers. Volume 1, Summary of condensation and fouling; Volume 2, Detailed study of steam condensation
Webb, R.L.; Chamra, L.; Jaber, H.
Electric utility steam condensers typically use plain tubes made of titanium, stainless steel, or copper alloys. Approximately two-thirds of the total thermal resistance is on the water side of the plain tube. This program seeks to conceive and develop a tube geometry that has special enhancement geometries on the tube (water) side and the steam (shell) side. This ``enhanced`` tube geometry, will provide increased heat transfer coefficients. The enhanced tubes will allow the steam to condense at a lower temperature. The reduced condensing temperature will reduce the turbine heat rate, and increase the plant peak load capability. Water side fouling and fouling control is a very important consideration affecting the choice of the tube side enhancement. Hence, we have consciously considered fouling potential in our selection of the tube side surface geometry. Using appropriate correlations and theoretical models, we have designed condensation and water side surface geometries that will provide high performance and be cleanable using sponge ball cleaning. Commercial tube manufacturers have made the required tube geometries for test purposes. The heat transfer test program includes measurement of the condensation and water side heat transfer coefficients. Fouling tests are being run to measure the waterside fouling resistance, and to the test the ability of the sponge ball cleaning system to clean the tubes.
Studies of the steam generator degraded tubes behavior on BRUTUS test loop
Chedeau, C.; Rassineux, B. [EDF/DER/MTC, Moret Sur Loing (France); Flesch, B. [EDF/EPN/DMAINT, Paris (France)] [and others
Studies for the evaluation of steam generator tube bundle cracks in PWR power plants are described. Global tests of crack leak rates and numerical calculations of crack opening area are discussed in some detail. A brief overview of thermohydraulic studies and the development of a mechanical probabilistic design code is also given. The COMPROMIS computer code was used in the studies to quantify the influence of in-service inspections and maintenance work on the risk of a steam generator tube rupture.
New tube bundle heat transfer correlations and flow regime maps for a Once Through Steam Generator
Blanchat, Thomas Kevin
completed which allow the user to input the pitch and tube o. d. for the system. Predicted RELAP5/MOD2 heat transfer coefficients from correlations have been reviewed for single phase liquid convection, subcooled, and saturated nu- cleate boiling... of the OTSG model to determine the "model efFects" prior to changing any thermal ? hydraulic correlations. These studies inves- tigated the effects of hydraulic diameter, tube bundle surface heat transfer area, snd inlet feedwater subcooling, in addition...
Tuning gain and bandwidth of traveling wave tubes using metamaterial beam-wave interaction structures
Lipton, Robert, E-mail: firstname.lastname@example.com; Polizzi, Anthony, E-mail: email@example.com [Department of Mathematics, Louisiana State University, Baton Rouge, Louisiana 70803-4918 (United States)
We employ metamaterial beam-wave interaction structures for tuning the gain and bandwidth of short traveling wave tubes. The interaction structures are made from metal rings of uniform cross section, which are periodically deployed along the length of the traveling wave tube. The aspect ratio of the ring cross sections is adjusted to control both gain and bandwidth. The frequency of operation is controlled by the filling fraction of the ring cross section with respect to the size of the period cell.
The effects of driver gas contamination on shock tube test time
Hawkins, Garry Owen
THE EFFECTS OF DRIVER GAS CONTAMINATION ON SHOCK TUBE TEST TIME A Thesis by CARRY OWEN HAWKINS Approved as to style and content by: (Chairman of Committee) (Head of Department) (Memb e r) (Member) (Member) (Membe r) (Member) December 1970... AB S TRACT The Effects of Driver Gas Contamination on Shock Tube Test Time. (December 1970) Garry 0. Hawkins, B. S. , Texas A&M University; Directed by: Dr. Richard E. Thomas The effects of driver gas contamination are manifested in a change...
Conceptual design of a pressure tube light water reactor with variable moderator control
Rachamin, R.; Fridman, E. [Reactor Safety Div., Inst. of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, POB 51 01 19, 01314 Dresden (Germany); Galperin, A. [Dept. of Nuclear Engineering, Ben-Gurion Univ. of the Negev, POB 653, Beer Sheva 84105 (Israel)
This paper presents the development of innovative pressure tube light water reactor with variable moderator control. The core layout is derived from a CANDU line of reactors in general, and advanced ACR-1000 design in particular. It should be stressed however, that while some of the ACR-1000 mechanical design features are adopted, the core design basics of the reactor proposed here are completely different. First, the inter fuel channels spacing, surrounded by the calandria tank, contains a low pressure gas instead of heavy water moderator. Second, the fuel channel design features an additional/external tube (designated as moderator tube) connected to a separate moderator management system. The moderator management system is design to vary the moderator tube content from 'dry' (gas) to 'flooded' (light water filled). The dynamic variation of the moderator is a unique and very important feature of the proposed design. The moderator variation allows an implementation of the 'breed and burn' mode of operation. The 'breed and burn' mode of operation is implemented by keeping the moderator tube empty ('dry' filled with gas) during the breed part of the fuel depletion and subsequently introducing the moderator by 'flooding' the moderator tube for the 'burn' part. This paper assesses the conceptual feasibility of the proposed concept from a neutronics point of view. (authors)
Four pin mounting system for nuclear reactor control rod guide tubes
Balog, L.J.; Boyle, D.E.
This paper describes a nuclear reactor having a control rod guide tube and an upper core plate, a pin-type mounting system for removably mounting the lower flange of a control rod guide tube over an opening in the upper core plate. It comprises: a pair of resilient pin members formed of stainless steel, mounted in passages formed through first opposing sides of the guide tube lower flange and resiliently and slidably receivable in a first pair of opposing bores formed on first opposing sides of the opening in the upper core plate to permit deflection thereof when the guide tube is subject to the usual shear loads associated with the operation of the nuclear reactor, the resilient pin members bearing substantially all of the usual shear load to which the guide tube is subjected. A paid of reinforcing pin members formed to stainless steel mounted on second opposing sides of the guide tube lower flange and slidably receivable in a second pair of bores formed on second opposing sides of the opening in the upper core plate.
High heat flux testing of a two-tube copper panel specimen for LLNL at ASURF
Easoz, J.R.; Sink, D.A.
This letter documents the results of the test program conducted for Lawrence Livermore National Laboratory (LLNL) by Westinghouse Advanced Energy Systems Division (AESD) in fulfillment of the Third Amendment to Subcontract 9125401. The original test matrix of 20,000 heating cycles on two test articles called for in the contract was not technically feasible due to the inability of the test articles supplied by LLNL to perform successfully at the required test conditions. Burnout occurred in one of the tubes of a two-tube target during the first series of tests. As a result, the work scope was changed by LLNL such that the tests on the milled copper plate panel specimen were replaced by a second set of heating tests on the second tube of the two-tube copper panel specimen to confirm the conditions for burnout failure. The testing requirements were completed following failure of the second tube at nominally identical conditions under which the first tube failed, and verification of these conditions. This letter completes all contractual obligations by serving as the final report on the test program.
Thermal-hydraulic instabilities in pressure tube graphite-moderated boiling water reactors
Tsiklauri, G.; Schmitt, B.
Thermally induced two-phase instabilities in non-uniformly heated boiling charmers in RBMK-1000 reactor have been analyzed using RELAP5/MOD3 code. The RELAP5 model of a RBMK-1000 reactor was developed to investigate low flow in a distribution group header (DGH) supplying 44 fuel pressure tubes. The model was evaluated against experimental data. The results of the calculations indicate that the period of oscillation for the high power tube varied from 3.1s to 2.6s, over the power range of 2.0 MW to 3.0 MW, respectively. The amplitude of the flow oscillation for the high powered tube varied from +100% to {minus}150% of the tube average flow. Reverse flow did not occur in the lower power tubes. The amplitude of oscillation in the subcooled region at the inlet to the fuel region is higher than in the saturated region at the outlet. In the upper fuel region and outlet connectors the flow oscillations are dissipated. The threshold of flow instability for the high powered tubes of a RBMK reactor is compared to Japanese data and appears to be in good agreement.
Shallow gas well drilling with coiled tubing in the San Juan Basin
Moon, R.G.; Ovitz, R.W.; Guild, G.J.; Biggs, M.D.
Coiled tubing is being utilized to drill new wells, for re-entry drilling to deepen or laterally extend existing wells, and for underbalanced drilling to prevent formation damage. Less than a decade old, coiled tubing drilling technology is still in its inaugral development stage. Initially, utilizing coiled tubing was viewed as a {open_quotes}science project{close_quotes} to determine the validity of performing drilling operations in-lieu of the conventional rotary rig. Like any new technology, the initial attempts were not always successful, but did show promise as an economical alternative if continued efforts were made in the refinement of equipment and operational procedures. A multiwell project has been completed in the San Juan Basin of Northwestern New Mexico which provides documentation indicating that coiled tubing can be an alternative to the conventional rotary rig. A 3-well pilot project, a 6-well project was completed uniquely utilizing the combined resources of a coiled tubing service company, a producing company, and a drilling contractor. This combination of resources aided in the refinement of surface equipment, personnel, mud systems, jointed pipe handling, and mobilization. The results of the project indicate that utilization of coiled tubing for the specific wells drilled was an economical alternative to the conventional rotary rig for drilling shallow gas wells.
The Synergism Between Heat and Mass Transfer Additive and Advanced Surfaces in Aqueous LiBr Horizontal Tube Absorbers
Miller, W.A.
Experiments were conducted in a laboratory to investigate the absorption of water vapor into a falling-film of aqueous lithium bromide (LiBr). A mini-absorber test stand was used to test smooth tubes and a variety of advanced tube surfaces placed horizontally in a single-row bundle. The bundle had six copper tubes; each tube had an outside diameter of 15.9-mm and a length of 0.32-m. A unique feature of the stand is its ability to operate continuously and support testing of LiBr brine at mass fractions {ge} 0.62. The test stand can also support testing to study the effect of the failing film mass flow rate, the coolant mass flow rate, the coolant temperature, the absorber pressure and the tube spacing. Manufacturers of absorption chillers add small quantities of a heat and mass transfer additive to improve the performance of the absorbers. The additive causes surface stirring which enhances the transport of absorbate into the bulk of the film. Absorption may also be enhanced with advanced tube surfaces that mechanically induce secondary flows in the falling film without increasing the thickness of the film. Several tube geometry's were identified and tested with the intent of mixing the film and renewing the interface with fresh solution from the tube wall. Testing was completed on a smooth tube and several different externally enhanced tube surfaces. Experiments were conducted over the operating conditions of 6.5 mm Hg absorber pressure, coolant temperatures ranging from 20 to 35 C and LiBr mass fractions ranging from 0.60 through 0.62. Initially the effect of tube spacing was investigated for the smooth tube surface, tested with no heat and mass transfer additive. Test results showed the absorber load and the mass absorbed increased as the tube spacing increased because of the improved wetting of the tube bundle. However, tube spacing was not a critical factor if heat and mass transfer additive was active in the mini-absorber. The additive dramatically affected the hydrodynamics of the falling film and a droplet flow regime was evident for testing at all tube spacings. The mechanical mixing of the advanced surfaces increased the mass transfer to about 75% of that observed on a smooth tube bundle, tested with heat and mass transfer additive. Testing with heat and mass transfer additive and advanced surfaces demonstrated a synergistic effect which doubled the mass absorbed from that observed with only the advanced surface. The overall film-side heat transfer coefficient for the advanced tube bundles doubled with the addition of 500-wppm of 2-ethyl-1- hexanol.
CFD Analysis Of Particle Transport In Axi-Symmetric Tubes Under The Influence Of Thermophoretic Force
Abarham, Mehdi [University of Michigan; Zamankhan, Parsa [University of Michigan; Hoard, John W. [University of Michigan; Styles, Dan [Ford Motor Company; Sluder, Scott [ORNL; Storey, John Morse [ORNL; Lance, Michael J [ORNL; Assanis, Dennis [University of Michigan
In this study, we developed two frameworks to investigate the thermophoretic particulate deposition in non-isothermal tube flows conveying particles ranging from 10 to 300 nm; a one dimensional model where the variables are assumed to be uniform in each cross section perpendicular to the tube axis and an axi-symmetric model where the aforementioned assumption is relaxed. In the one dimensional model, the rate of mass deposition along the inner surface of the tube is computed based on the local thermophoretic velocity of the particulate phase at the wall. This velocity is proportional to the radial gradient of the temperature at the wall and is calculated via some empirical correlations for heat transfer in tube flows. In the axi-symmetric model, the rate of deposition is computed through the Fick s law after solving the species transport equation for the solid phase. We included the formation of the soot layer through moving the gas solid interface in both models. The tube effectiveness (the ratio of actual heat transfer to the maximum possible heat transfer) decreases due to the formation of the layer. Model outputs including deposited mass along the tube wall and the tube effectiveness drop have been compared against experiments. While the computed results through both models agree with the trend of experimental data, the axi-symmetric results are closer to the experiments in most cases. The calculated deposited mass is smaller (and closer to experiments) for the axi-symmetric model compared to the one dimensional model in all cases. This indicates that the axi-symmetric model estimates the deposited mass more accurately.
Steam generator tube integrity program. Semiannual report, August 1995--March 1996
Diercks, D.R.; Bakhtiari, S.; Chopra, O.K. [and others
This report summarizes work performed by Argonne National Laboratory on the Steam Generator Tube Integrity Program from the inception of that program in August 1995 through March 1996. The program is divided into five tasks, namely (1) Assessment of Inspection Reliability, (2) Research on ISI (in-service-inspection) Technology, (3) Research on Degradation Modes and Integrity, (4) Development of Methodology and Technical Requirements for Current and Emerging Regulatory Issues, and (5) Program Management. Under Task 1, progress is reported on the preparation of and evaluation of nondestructive evaluation (NDE) techniques for inspecting a mock-up steam generator for round-robin testing, the development of better ways to correlate burst pressure and leak rate with eddy current (EC) signals, the inspection of sleeved tubes, workshop and training activities, and the evaluation of emerging NDE technology. Under Task 2, results are reported on closed-form solutions and finite element electromagnetic modeling of EC probe response for various probe designs and flaw characteristics. Under Task 3, facilities are being designed and built for the production of cracked tubes under aggressive and near-prototypical conditions and for the testing of flawed and unflawed tubes under normal operating, accident, and severe accident conditions. In addition, crack behavior and stability are being modeled to provide guidance on test facility design, to develop an improved understanding of the expected rupture behavior of tubes with circumferential cracks, and to predict the behavior of flawed and unflawed tubes under severe accident conditions. Task 4 is concerned with the cracking and failure of tubes that have been repaired by sleeving, and with a review of literature on this subject.
Failure Pressure Estimates of Steam Generator Tubes Containing Wear-type Defects
Yoon-Suk Chang; Jong-Min Kim; Nam-Su Huh; Young-Jin Kim [School of Mechanical Engineering, Sungkyunkwan University (Korea, Republic of); Seong Sik Hwang; Joung-Soo Kim [Korea Atomic Energy Research Institute (Korea, Republic of)
It is commonly requested that steam generator tubes with defects exceeding 40% of wall thickness in depth should be plugged to sustain all postulated loads with appropriate margin. The critical defect dimensions have been determined based on the concept of plastic instability. This criterion, however, is known to be too conservative for some locations and types of defects. In this context, the accurate failure estimation for steam generator tubes with a defect draws increasing attention. Although several guidelines have been developed and are used for assessing the integrity of defected tubes, most of these guidelines are related to stress corrosion cracking or wall-thinning phenomena. As some of steam generator tubes are also failed due to fretting and so on, alternative failure estimation schemes for relevant defects are required. In this paper, three-dimensional finite element (FE) analyses are carried out under internal pressure condition to simulate the failure behavior of steam generator tubes with different defect configurations; elliptical wastage type, wear scar type and rectangular wastage type defects. Maximum pressures based on material strengths are obtained from more than a hundred FE results to predict the failure of the steam generator tube. After investigating the effect of key parameters such as wastage depth, wastage length and wrap angle, simplified failure estimation equations are proposed in relation to the equivalent stress at the deepest point in wastage region. Comparison of failure pressures predicted according to the proposed estimation scheme with some corresponding burst test data shows good agreement, which provides a confidence in the use of the proposed equations to assess the integrity of steam generator tubes with wear-type defects. (authors)
Heat Transfer Enhancement for Finned-Tube Heat Exchangers with Vortex Generators: Experimental and Numerical Results
O'Brien, James Edward; Sohal, Manohar Singh; Huff, George Albert
A combined experimental and numerical investigation is under way to investigate heat transfer enhancement techniques that may be applicable to large-scale air-cooled condensers such as those used in geothermal power applications. The research is focused on whether air-side heat transfer can be improved through the use of finsurface vortex generators (winglets,) while maintaining low heat exchanger pressure drop. A transient heat transfer visualization and measurement technique has been employed in order to obtain detailed distributions of local heat transfer coefficients on model fin surfaces. Pressure drop measurements have also been acquired in a separate multiple-tube row apparatus. In addition, numerical modeling techniques have been developed to allow prediction of local and average heat transfer for these low-Reynolds-number flows with and without winglets. Representative experimental and numerical results presented in this paper reveal quantitative details of local fin-surface heat transfer in the vicinity of a circular tube with a single delta winglet pair downstream of the cylinder. The winglets were triangular (delta) with a 1:2 height/length aspect ratio and a height equal to 90% of the channel height. Overall mean fin-surface Nusselt-number results indicate a significant level of heat transfer enhancement (average enhancement ratio 35%) associated with the deployment of the winglets with oval tubes. Pressure drop measurements have also been obtained for a variety of tube and winglet configurations using a single-channel flow apparatus that includes four tube rows in a staggered array. Comparisons of heat transfer and pressure drop results for the elliptical tube versus a circular tube with and without winglets are provided. Heat transfer and pressure-drop results have been obtained for flow Reynolds numbers based on channel height and mean flow velocity ranging from 700 to 6500.
The U-tube sampling methodology and real-time analysis of geofluids
Freifeld, Barry; Perkins, Ernie; Underschultz, James; Boreham, Chris
The U-tube geochemical sampling methodology, an extension of the porous cup technique proposed by Wood [1973], provides minimally contaminated aliquots of multiphase fluids from deep reservoirs and allows for accurate determination of dissolved gas composition. The initial deployment of the U-tube during the Frio Brine Pilot CO{sub 2} storage experiment, Liberty County, Texas, obtained representative samples of brine and supercritical CO{sub 2} from a depth of 1.5 km. A quadrupole mass spectrometer provided real-time analysis of dissolved gas composition. Since the initial demonstration, the U-tube has been deployed for (1) sampling of fluids down gradient of the proposed Yucca Mountain High-Level Waste Repository, Armagosa Valley, Nevada (2) acquiring fluid samples beneath permafrost in Nunuvut Territory, Canada, and (3) at a CO{sub 2} storage demonstration project within a depleted gas reservoir, Otway Basin, Victoria, Australia. The addition of in-line high-pressure pH and EC sensors allows for continuous monitoring of fluid during sample collection. Difficulties have arisen during U-tube sampling, such as blockage of sample lines from naturally occurring waxes or from freezing conditions; however, workarounds such as solvent flushing or heating have been used to address these problems. The U-tube methodology has proven to be robust, and with careful consideration of the constraints and limitations, can provide high quality geochemical samples.
Continuous-wave radar to detect defects within heat exchangers and steam generator tubes.
Nassersharif, Bahram (New Mexico State University, Las Cruces, NM); Caffey, Thurlow Washburn Howell; Jedlicka, Russell P. (New Mexico State University, Las Cruces, NM); Garcia, Gabe V. (New Mexico State University, Las Cruces, NM); Rochau, Gary Eugene
A major cause of failures in heat exchangers and steam generators in nuclear power plants is degradation of the tubes within them. The tube failure is often caused by the development of cracks that begin on the outer surface of the tube and propagate both inwards and laterally. A new technique was researched for detection of defects using a continuous-wave radar method within metal tubing. The experimental program resulted in a completed product development schedule and the design of an experimental apparatus for studying handling of the probe and data acquisition. These tests were completed as far as the prototypical probe performance allowed. The prototype probe design did not have sufficient sensitivity to detect a defect signal using the defined radar technique and did not allow successful completion of all of the project milestones. The best results from the prototype probe could not detect a tube defect using the radar principle. Though a more precision probe may be possible, the cost of design and construction was beyond the scope of the project. This report describes the probe development and the status of the design at the termination of the project.
An investigation of the effect of a propellant liner in the launch tube of a hypervelocity accelerator�
Schappaugh, Ronald Dean
from a five foot one-eighth inch diameter launch tube. 20 CHAPTER IV EXPERINENTAL FACILITIES AND EQUIPMENT Accelerator To test the effect of a propellant liner, a powder gun accelerator was designed in such a manner to permit coating...'. "" 1 . h 22 entering the tube. 1t was thought that the propellant liner would more readily ignite, if the projectile had an initial velocity when it entered the coated tube. The system was designed so that the pistol could be triggered...
Synchrotron radiation and beam tube vacuum in a Very Large Hadron Collider, Stage 1 and Stage 2 VLHC
Pivi, M.; Turner, W.C.; Bauer, P.; Limon, P.
et al. "Synchrotron radiation issues in the VLHC" theseSYNCHROTRON RADIATION AND BEAM TUBE VACUUM IN A VERY LARGEUSA Abstract Synchrotron radiation induced photodesorption
Analysis of Refrigerant Flow and Deformation for a Flexible Short-Tube using a Finite Element Model
O'Neal, D.L.; Bassiouny, R.
reliability. Short-tubes have either a constant inner dia- meter flow channel or a tapered channel with a smallAbstract A finite element model was used to simulate single-phase flow of R-22 through flexible short-tubes. The numerical model included the fluid... in the flow area. The more flexible (5513 kPa) short-tube restricted the mass flow rate more than the most rigid (9889 kPa) short-tube used in this study. The mass flow rates estimated with the finite element model were as much as 14% higher than those from...
Cutoff-Free Propagation of Torsional Alfv�n Waves Along Thin Magnetic Flux Tubes
Z. E. Musielak; S. Routh; R. Hammer
Propagation of torsional Alfv\\'en waves along magnetic flux tubes has been extensively studied for many years but no conclusive results regarding the existence of a cutoff frequency for these waves have been obtained. The main purpose of this paper is to derive new wave equations that describe the propagation of linear torsional Alfv\\'en waves along thin and isothermal magnetic flux tubes, and use these wave equations to demonstrate that the torsional wave propagation is not affected by any cutoff frequency. It is also shown that this cutoff-free propagation is independent of different choices of the coordinate systems and wave variables adopted in the previous studies. A brief discussion of implications of this cutoff-free propagation of torsional tube waves on theories of wave heating of the solar and stellar atmospheres is also given.
Failure probability of axially cracked steam generator tubes; A probabilistic fracture mechanics model
Mavko, B.; Cizelj, L. (Jozef Stefan Inst., Reactor Engineering Div., P.O. Box 100, 61111 Ljubljana, Slovenia (YU))
In this paper a model for estimating the failure probability of axially cracked steam generator tubes is proposed. The model compares observed crack length distribution with critical crack length distribution by means of probabilistic fracture mechanics. The observed crack length is influenced by measured data, measurement reliability, sizing accuracy, and predicted crack growth rate. The critical crack length is defined by a deterministic mechanical model. All cracks are conservatively assumed to extend through the tube wall. The effect of the plugging limit is studied along with the number of cracked tubes to perform risk-based lifetime optimization of steam generators. A numerical example presented considers hypothetical accidental operating conditions during a feedwater line break.
A Review of Some Degradation Mechanisms in CANDU Steam Generator Tubing
Ogundele, G.; Clark, M.; Goszczynski, G.; Lloyd, A. [Kinectrics, Inc., 800 Kipling Avenue Toronto, Ontario M8Z 6C4 (Canada); Pagan, S. [Ontario Power Generation, 700 University Avenue Toronto, Ontario, M5G 1X6 (Canada); Sedman, K. [Bruce Power, P.O. Box 3000 177 Tie Rd., R.R. 2, Tiverton, Ontario N0G 2T0 (Canada); King, P. [Babcock and Wilcox (Canada)
The first CANDU (Canadian Deuterium Uranium) pressurized heavy water reactor (PHWR) went into operation in July 1971. Today, there are several units in operation at the Pickering, Bruce, and Darlington sites in Ontario, Canada. The steam generator tubing materials were manufactured from Monel 400, Inconel 600, and Incoloy 800 for the Pickering, Bruce, and Darlington respectively and are subjected to different operating conditions. This paper presents a review of some of the various types of degradation mechanisms that have been observed on these tubing materials over the operating period of the respective plants. The results presented are based on the metallurgical examination of removed tubes. The mechanisms that have been observed include pitting, stress corrosion cracking, intergranular attack, fretting, and erosion corrosion. The nature of the flaws and causative factors (if known) are discussed. (authors)
Development of a model of an x-ray tube transmission source
Goda, Joetta M [Los Alamos National Laboratory; Ianakiev, Kiril D [Los Alamos National Laboratory; Moss, Cal E [Los Alamos National Laboratory
In support of the development of an x-ray tube based source for transmission measurements of UF6 gas, we have developed a one-dimensional, spreadsheet-based model of the source. Starting with the spectrum produced by an x-ray tube we apply the linear attenuation coefficients for various notch filters, the aluminum pipe, and UF6 gas. This model allows calculation of the transmitted spectrum based on the type of filter, the thickness of the filter, the x-ray tube high voltage, the Al pipe thickness, and the UF6 gas pressure. The sensitivity of the magnitude of the transmission peak produced by the notch filter to any of these variables can be explored quickly and easily to narrow the choices for experimental measurements. To validate the spreadsheet based model, comparisons have been made to various experimental data.
Ion beam characteristics of the controlatron/zetatron family of the gas filled neutron tubes
Berg, R.S.; Shope, L.A.; O'Neal, M.L.; Boers, J.E.; Bickes, R.W. Jr.
A gas filled tube used to produce a neutron flux with the D(T,He/sup 4/)n reaction is described. Deuterium and tritium ions generated in a reflex discharge are extracted and accelerated to 100 keV by means of an accelerator electrode onto a deutero-tritide target electrode. The electrodes are designed to focus the ion beam onto the target. Total tube currents consisting of extracted ions, unsuppressed secondary electrons, and ions generated by interactions with the background gas are typically 100 mA. The characteristics of the extracted ion beam are discussed. Accelerating voltages greater than 50 kV are required to focus the beam through the accelerator aperture for configurations that give beams with the proper energy density onto the target. The perveance of the beam is discussed. Maximum perveance values are 2 to 20 nanopervs. Tube focusing and neutron production characteristics are described.
High field pulsed microwiggler comprising a conductive tube with periodically space slots
Warren, Roger W. (Santa Fe, NM)
A microwiggler assembly produces large magnetic fields for oscillating ched particle beams, particularly electron beams for free electron laser (FEL) application. A tube of electrically conductive material is formed with radial slots axially spaced at the period of the electron beam. The slots have alternate 180.degree. relationships and are formed to a maximum depth of 0.6 to 0.7 times the tube circumference. An optimum slot depth is selected to eliminate magnetic quadrupole fields within the microwiggler as determined from a conventional pulsed wire technique. Suitable slot configurations include single slits, double slits, triple slits, and elliptical slots. An axial electron beam direction is maintained by experimentally placing end slits adjacent entrance and exit portions of the assembly, where the end slit depth is determined by use of the pulsed wire technique outside the tube.
High field pulsed microwiggler comprising a conductive tube with periodically space slots
Warren, R.W.
A microwiggler assembly produces large magnetic fields for oscillating charged particle beams, particularly electron beams for free electron laser (FEL) application. A tube of electrically conductive material is formed with radial slots axially spaced at the period of the electron beam. The slots have alternate 180[degree] relationships and are formed to a maximum depth of 0.6 to 0.7 times the tube circumference. An optimum slot depth is selected to eliminate magnetic quadrupole fields within the microwiggler as determined from a conventional pulsed wire technique. Suitable slot configurations include single slits, double slits, triple slits, and elliptical slots. An axial electron beam direction is maintained by experimentally placing end slits adjacent entrance and exit portions of the assembly, where the end slit depth is determined by use of the pulsed wire technique outside the tube. 10 figs.
Ion-induced swelling of ODS ferritic alloy MA957 tubing to 500 dpa
Toloczko, Mychailo B.; Garner, F. A.; Voyevodin, V.; Bryk, V. V.; Borodin, O. V.; Melnichenko, V. V.; Kalchenko, A. S.
In order to study the potential swelling behavior of the ODS ferritic alloy MA957 at very high dpa levels, specimens were prepared from pressurized tubes that were unirradiated archives of tubes previously irradiated in FFTF to doses as high at 110 dpa. These unirradiated specimens were irradiated with 1.8 MeV Cr+ ions to doses ranging from 100 to 500 dpa and examined by transmission electron microscopy. No coinjection of helium or hydrogen was employed. It was shown that compared to several ferritic/martensitic steels irradiated in the same facility, these tubes were rather resistant to void swelling, reaching a maximum value of only 4.5% at 500 dpa and 450�C. In this fine-grained material, the distribution of swelling was strongly influenced by the presence of void denuded zones along the grain boundaries.
Incidence of Dental Caries in Tube-Fed Children and Tube-fed Children Receiving Oral Feeding Therapy: A Retrospective Analysis�
Morgan, Benjamin P
food.9 A child with a moderate disorder such as feeding inefficiency, may be effectively managed with caloric supplementation via glucose polymer feeds.10 However, a child with a severe degree of oral-motor dysfunction can have multiple medical...) through a child�s nostril and positioned into the stomach. This method is generally reserved for short-term nutritional supplementation.10 Common disorders that often require tube placement include failure to thrive, inadequate caloric intake, severe...
Development of Radar Navigation and Radio Data Transmission for Microhole Coiled Tubing Bottom Hole Assemblies
Larry G. Stolarczyk; Gerald L. Stolarczyk; Larry Icerman; John Howard; Hooman Tehrani
This Final Technical Report summarizes the research and development (R&D) work performed by Stolar Research Corporation (Stolar) under U.S. Department of Energy (DOE) Contract Number DE-FC26-04NT15477. This work involved the development of radar navigation and radio data transmission systems for integration with microhole coiled tubing bottom hole assemblies. Under this contract, Stolar designed, fabricated, and laboratory and field tested two advanced technologies of importance to the future growth of the U.S. oil and gas industry: (1) real-time measurement-while-drilling (MWD) for guidance and navigation of coiled tubing drilling in hydrocarbon reservoirs and (2) two-way inductive radio data transmission on coiled tubing for real-time, subsurface-to-surface data transmission. The operating specifications for these technologies are compatible with 3.5-inch boreholes drilled to a true vertical depth (TVD) of 5,000 feet, which is typical of coiled tubing drilling applications. These two technologies (i.e., the Stolar Data Transmission System and Drill String Radar) were developed into pre-commercial prototypes and tested successfully in simulated coiled tubing drilling conditions. Integration of these two technologies provides a real-time geosteering capability with extremely quick response times. Stolar is conducting additional work required to transition the Drill String Radar into a true commercial product. The results of this advanced development work should be an important step in the expanded commercialization of advanced coiled tubing microhole drilling equipment for use in U.S. hydrocarbon reservoirs.
Structural characterization and structural/material similitude of hybrid composite tubes
Liggett, Glade Michael
of circumferential E-glass/epoxy layers which resist bursting stresses and longitudinal carbon/epoxy layers which resist the axial stresses created by the applied tension [5]. This is shown in Figure l. Although all glass/epoxy and all carbon/epoxy tubes were... response and failure prediction of E-glass/epoxy composite tubes exposed to internal pressure, axial tension, and hygrothermal loading was examined by Farivar-Sadri using the finite eleinent method [9]. The results of this analytical model agreed closely...
A Multi-Anode Photomultiplier Tube Based Wavelength-Shifting-Fiber Detector for neutron diffraction
Berry, Kevin D [ORNL; Clonts, Lloyd G [ORNL; Crow, Lowell [ORNL; Diawara, Yacouba [ORNL; Funk, Loren L [ORNL; Hannan, Bruce W [ORNL; Hodges, Jason P [ORNL; Riedel, Richard A [ORNL; Wang, Cai-Lin [ORNL
The wavelength-shifting (WLS) fiber scintillator neutron detectors were developed for two time-of-flight (TOF) neutron powder diffractometers (POWGEN, VULCAN) at Spallation Neutron Source (SNS). In a recent module (v3.0), however, there are 32 1-inch-diameter photomultiplier tubes (PMTs) which are bulky and expensive. We built a new detector module (v3.1) based on four multi-anode (MA) PMTs, and tested its performance including detection efficiency, count rate capability, spatial resolution, ghosting properties, and gamma-ray sensitivity. The v3.1 module was compared with two prior v3.0 modules, and 3He tube detectors.
Fourier analysis of the flux-tube distribution in SU(3) lattice QCD
Arata Yamamoto
This letter presents a novel analysis of the action/energy density distribution around a static quark-antiquark pair in SU(3) lattice quantum chromodynamics. Using the Fourier transformation of the link variable, we remove the high-momentum gluon and extract the flux-tube component from the action/energy density. When the high-momentum gluon is removed, the statistical fluctuation is drastically suppressed, and the singularities from the quark self-energy disappear. The obtained flux-tube component is broadly distributed around the line connecting the quark and the antiquark.
A Series of Tubes: Adding Interactivity to 3D Prints Using Internal Pipes
Zakhor, Avideh
A Series of Tubes: Adding Interactivity to 3D Prints Using Internal Pipes Valkyrie Savage valkyrie flexibility and potential. Author Keywords Fabrication; 3D Printing; Interactive Objects; Design Tools ACM. Recently, human-computer interaction researchers have be- gun to explore adding interaction to 3D printed
Jaszczak et al. 1 MICRO-AND NANO-SCALE GRAPHITE CONES AND TUBES FROM HACKMAN
Jaszczak, John A.
of micro- and nano-scale RGS. The largest of the RGS are hollow scrolls, with the c-axis predominantly at the micro- and nano-scales. The nano-scale cones tend not to be hollow and may have a cone-helix structureJaszczak et al. 1 MICRO- AND NANO-SCALE GRAPHITE CONES AND TUBES FROM HACKMAN VALLEY, KOLA
Process for sensing defects on a smooth cylindrical interior surface in tubing
Dutton, G.W.
The cylindrical interior surface of small diameter metal tubing is optically inspected to determine surface roughness by passing a slightly divergent light beam to illuminate the entire interior surface of the tubing. Impingement of the input light beam components on any rough spots on the interior surface generates forward and backward scattered radiation components. The forward scattered components can be measured by blocking direct and specular radiation components exiting the tubing while allowing the forward scattered radiation to travel past the blocking location. Collecting optics are employed to converge the forward scattered radiation onto a photodetector generating a signal indicative of surface roughness. In the back scattered mode, back scattered radiation exiting the tubing through the entrance opening is reflected 90[degree] by a beam splitter towards collecting optics and a photodetector. Alternatively, back scattered radiation can be transmitted through a fiber optic bundle towards the collecting optics. The input light beam can be supplied through a white light fiber optic bundle mounted coaxial with the first bundle. 6 figs.
Tube-based distributed control of linear constrained systems Stefano Riverso a
Ferrari-Trecate, Giancarlo
Tube-based distributed control of linear constrained systems Stefano Riverso a , Giancarlo Ferrari in [20] for linear systems and aim at approximating centralized MPC controllers. However, they require, 27100 Pavia, Italy Abstract In this paper we consider a linear system structured into physically coupled
Bernoulli Applications A Venturi meter is used to measure the flow rate through a tube.
Weijgaert, Rien van de
04/03/2014 1 Bernoulli Applications A Venturi meter is used to measure the flow rate through a tube: as the flow is horizontal, we do not have to take into account the gravity term. 2) Continuity equation-1822), an Italian physicist. Look at the construction in figure: - we assume the flow is smooth and effectively
L'lectrisation du cyclohexane en coulement laminaire dans des tubes mtalliques.
Paris-Sud XI, Universit� de
Abstracts 73.30 - 73.40B - 82.65 Introduction. L'�lectrisation d'hydrocarbures s'�coulant dans des tubes), quand on les dissout en faible quantit� ( 10- 3 mole 1 - 1) dans les hydrocarbures. Pourtant, le
IEEE TRANS. MAGN., SUBMITTED 1 3D Eddy-Current Imaging of Metal Tubes by
Paris-Sud XI, Universit� de
IEEE TRANS. MAGN., SUBMITTED 1 3D Eddy-Current Imaging of Metal Tubes by Gradient-Based, Controlled, and Oliver Dorn Abstract--Eddy-current non-destructive testing is widely used to detect defects within-developed binary-specialized method. Index Terms--eddy-current non-destructive testing, impedance variations, level
Process and apparatus for sensing defects on a smooth cylindrical surface in tubing
Dutton, G.W.
The cylindrical interior surface of small diameter metal tubing is optically inspected to determine surface roughness by passing a slightly divergent light beam to illuminate the entire interior surface of the tubing. Impingement of the input light beam components on any rough spots on the interior surface generates forward and backward scattered radiation components. The forward scattered components can be measured by blocking direct and specular radiation components exiting the tubing while allowing the forward scattered radiation to travel past the blocking location. Collecting optics are employed to converge the forward scattered radiation onto a photodetector generating a signal indicative of surface roughness. In the back scattered mode, back scattered radiation exiting the tubing through the entrance opening is reflected 90/sup 0/ by a beam splitter towards collecting optics and a photodetector. Alternatively, back scattered radiation can be transmitted through a fiber optic bundle towards the collecting optics. The input light beam can be supplied through a white light fiber optic bundle mounted coaxial with the first bundle.
Interweaving 3D Network with Double Helical Tubes Filled by 1D Coordination Polymer Chains
Gao, Song
Interweaving 3D Network with Double Helical Tubes Filled by 1D Coordination Polymer Chains E Yang- tecture interpenetrated by three types of coordination polymer motifs. Two independent {[Cu2(mellitate)(4,4-bpy)(H2O)2]2- } 3D polymers incorporating helical substructures were interwoven into a 3D network
The Geometry of Intersecting Tubes Applied to Controlling a Robotic Welding Torch
Stockie, John
The Geometry of Intersecting Tubes Applied to Controlling a Robotic Welding Torch John M. Stockie Abstract: The question of how to control a robotic welding torch to trace the joint between two cylindrical that increase its applicability to more advanced mathematics courses. Keywords: pipe welding, cylinders
Analysis of the tube-sheet cracking in slurry oil steam , L.J. Qiao a,
Volinsky, Alex A.
-sheet cracking is a severe problem in the oil refinery industry with the consequences of shortened service life steam generator is a kind of shell and tube heat exchanger extensively used in the oil refinement in the oil refinery industry. Previous study has shown that corrosion, such as stress corrosion cracking (SCC
Risk assessment of severe accident-induced steam generator tube rupture
This report describes the basis, results, and related risk implications of an analysis performed by an ad hoc working group of the U.S. Nuclear Regulatory Commission (NRC) to assess the containment bypass potential attributable to steam generator tube rupture (SGTR) induced by severe accident conditions. The SGTR Severe Accident Working Group, comprised of staff members from the NRC`s Offices of Nuclear Reactor Regulation (NRR) and Nuclear Regulatory Research (RES), undertook the analysis beginning in December 1995 to support a proposed steam generator integrity rule. The work drew upon previous risk and thermal-hydraulic analyses of core damage sequences, with a focus on the Surry plant as a representative example. This analysis yielded new results, however, derived by predicting thermal-hydraulic conditions of selected severe accident scenarios using the SCDAP/RELAP5 computer code, flawed tube failure modeling, and tube failure probability estimates. These results, in terms of containment bypass probability, form the basis for the findings presented in this report. The representative calculation using Surry plant data indicates that some existing plants could be vulnerable to containment bypass resulting from tube failure during severe accidents. To specifically identify the population of plants that may pose a significant bypass risk would require more definitive analysis considering uncertainties in some assumptions and plant- and design-specific variables. 46 refs., 62 figs., 37 tabs.
The U-tube: A new paradigm in borehole fluid sampling
Freifeld, B. M.
Fluid samples from deep boreholes can provide insights into subsurface physical, chemical, and biological conditions. Recovery of intact, minimally altered aliquots of subsurface fluids is required for analysis of aqueous chemistry, isotopic composition, and dissolved gases, and for microbial community characterization. Unfortunately, for many reasons, collecting geofluids poses a number of challenges, from formation contamination by drilling to maintaining integrity during recovery from depths. Not only are there substantial engineering issues in retrieval of a representative sample, but there is often the practical reality that fluid sampling is just one of many activities planned for deep boreholes. The U-tube geochemical sampling system presents a new paradigm for deep borehole fluid sampling. Because the system is small, its ability to integrate with other measurement systems and technologies opens up numerous possibilities for multifunctional integrated wellbore completions. To date, the U-tube has been successfully deployed at four different field sites, each with a different deployment modality, at depths from 260 m to 2 km. While the U-tube has proven to be highly versatile, these installations have resulted in data that provide additional insights for improving future U-tube deployments.
Standard practice for in situ examination of ferromagnetic Heat-Exchanger tubes using remote field testing
American Society for Testing and Materials. Philadelphia
1.1 This practice describes procedures to be followed during remote field examination of installed ferromagnetic heat-exchanger tubing for baseline and service-induced discontinuities. 1.2 This practice is intended for use on ferromagnetic tubes with outside diameters from 0.500 to 2.000 in. [12.70 to 50.80 mm], with wall thicknesses in the range from 0.028 to 0.134 in. [0.71 to 3.40 mm]. 1.3 This practice does not establish tube acceptance criteria; the tube acceptance criteria must be specified by the using parties. 1.4 Units�The values stated in either inch-pound units or SI units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this practice to establ...
Comparison of two models of a Double Inlet Miniature Pulse Tube Refrigerator : Part B Electrical Analogy
Paris-Sud XI, Université de
Inlet Pulse Tube Refrigerator is investigated by means of an analogy with an electric circuit) and experiments. The basic formulation of equivalent electronic components is discussed and a few improvements to avoid mechanical vibrations and magnetic fields. Therefore, a third capillary is used to link
Effect of surface conditions on boiling heat transfer of refrigerants in shell-and-tube evaporators
Danilova, G.N.; Dyundin, V.A.; Borishanskaya, A.V.; Soloviyov, A.G.; Vol'nykh, Y.A.; Kozyrev, A.A.
Experimental results are presented for the boiling heat transfer performance of R 22 and R 717 on surfaces with porous metallized coatings. A calculational-theoretical model is given for predicting the heat transfer of refrigerants boiling on a bundle of finned tubes.
Transition pathways in complex systems: Reaction coordinates, isocommittor surfaces, and transition tubes
Van Den Eijnden, Eric
Transition pathways in complex systems: Reaction coordinates, isocommittor surfaces, and transition form 20 July 2005 Available online 18 August 2005 Abstract The mechanism of transition (reaction. These surfaces can be used to identify effective transition tubes inside which the reactive trajectories involved
Fracture of Zircaloy-4 Cladding Tubes with or without Hydride Blisters in Uniaxial to Plane
Paris-Sud XI, Université de
) scenario in a nuclear pressurized water reactor is a control rod ejection that induces a large energy, Hy- dride Blister 1 Introduction The most critical postulated reactivity Initiated Accident (RIA rods expand suddenly, which induces deformation of the cladding tubes in the first phase referred
Freezing controlled penetration of molten metals flowing through stainless steel tubes
Sienicki, J.J.; Spencer, B.W.; Vetter, D.L.; Wesel, R.H.
The freezing controlled penetration potential of molten metals flowing within stainless steel structure is important to the safety assessment of hypothetical severe accidents in liquid metal reactors. A series of scoping experiments has been performed in which molten stainless steel and nickel at various initial temperatures and driving pressures were injected downward and upward into 6.4 and 3.3 mm ID stainless steel tubes filled with argon gas and initially at room temperature. In all tests, there was no evidence that the solid tube wall was wetted by the molten metals. The penetration phenomena are markedly different for downward versus upward injections. The dependency upon tube orientation is explained in terms of the absence of wetting. Complete plugs were formed in all experiments halting the continued injection of melt. Calculations with a fluid dynamics/heat transfer computer code show that the injected masses limited by plugging are consistent with freezing through the growth of a stable solidified layer (crust) of metal upon the solid tube wall. 23 refs., 5 figs., 2 tabs.
Improved helium exchange gas cryostat and sample tube designs for automated gas sampling and cryopumping
Severinghaus, Jeffrey P.
Improved helium exchange gas cryostat and sample tube designs for automated gas sampling, California 92093-0244, USA [1] In order to eliminate the use of liquid helium for the extraction of atmospheric gases from polar ice cores, two units of a redesigned top load helium exchange gas cryostat were
Machine Learning and Inference Laboratory An Optimized Design of Finned-Tube Evaporators
Michalski, Ryszard S.
.firstname.lastname@example.com;{kaufman, email@example.com http://www.mli.gmu.edu Abstract Optimizing the refrigerant circuitry for a finned9906858. The National Institute of Standards and Technology (NIST), the Air Conditioning and Refrigeration-tube air-to-refrigerant heat exchanger is affected by a multitude of factors related to its design
Crystallographic texture for tube and plate of the superelastic/shape-memory alloy Nitinol used for
Ritchie, Robert
Crystallographic texture for tube and plate of the superelastic/shape-memory alloy Nitinol used in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/jbm.a.30214 Abstract: The superelastic/shape-memory equiatomic nickel�titanium alloy known for its shape memory, superelastic properties, and biocompatibility
Creating Enriched YouTube Media Fragments With NERD Using Timed-Text
Quartly, Graham
Introduction New W3C standards such as HTML5, Media Fragment URI and the Ontology for Media Resources have their closed captions [4]. The captions are ana- lyzed by 3 web services (AlchemyAPI, OpenCalais and Zemanta) The system first extracts the metadata and the subtitles if available using the YouTube API: GET api
The oscillations of a magnetic flux tube and its application to sunspots
Evans, D.J.; Roberts, B. (Saint Andrews Univ. (Scotland))
The modes of oscillation of an isolated magnetic flux tube in the absence of gravity is examined, with parameters chosen to mimic a sunspot. Gravitational stratification of the umbral atmosphere leads to consider two cases, distinguished primarily by the ordering of the Alfven speed and the external sound speed. The transition between these two regimes occurs at about the level where the optical depth, tau(c), is equal to 1 in the umbra. The modes given by the model, taken together with the observations, suggest that 3 minute oscillations are slow-body modes (driven by overstable convection) and that a sunspot consists of a bundle of pore-sized flux tubes rather than a single monolithic one. Fast-body modes are identified in the tube with the observed 5 minute oscillations of the umbral photosphere and below. The excitation of these modes propagating up or down the tube may explain the recent observation that sunspots act as sinks for p-modes propagating in their environment. Running penumbral waves are associated with fast- and slow-surface modes. The fast-surface wave could arise from fast-body modes driven below the level where tau(c) = 1; the slow-surface waves may arise from granular buffeting or overstable convection. 55 refs.
Experimental shellside flow visualization in a shell and tube heat exchanger�
Fischer, Matthew Winslow
information in the shellside flow. A scale-model shell and tube heat exchanger with an outer diameter of 30.5 cm and a length of 61 cm was designed and constructed out of acrylic. Water was utilized as the working fluid and flowrates ranging from 0.32 to 2...
4-H Trashion Show Instructions for posting video to YouTube
4-H Trashion Show Instructions for posting video to YouTube Note: Once you edit your video, make;4. Click on "Upload Video." Depending upon your connection, the uploading process can take a while. 5. Once your video has loaded, you will get the following screen. Complete the information noted below. Preview
Page 1 of 2 How to Upload Videos to YouTube
Engel, Robert
Page 1 of 2 How to Upload Videos to YouTube To submit a video to the event, you should make a 30-to-60-second video. You can use your cell phone, a video camera, your webcam, or other sources for your video. You can use various video editing programs to make your video, including iMovie (on Macs
Error Analysis of Heat Transfer for Finned-Tube Heat-Exchanger Text-Board�
Chen, Y.; Zhang, J.
In order to reduce the measurement error of heat transfer in water and air side for finned-tube heat-exchanger as little as possible, and design a heat-exchanger test-board measurement system economically, based on the principle of test-board system...
Oxy-acetylene driven laboratory scale shock tubes for studying blast wave effects
Courtney, Michael
Instrumentation is needed to produce realistic blast waves in a laboratory setting. This paper describes the development and characterization of oxy-acetylene driven, laboratory scale shock tubes for use in studying blast injury, candidate armor materials, and material properties at blast loading rates. The pressure-time profiles show a true shock front and exponential decay characteristic of blast waves and have relevant durations. The modular design includes shock tube diameters of 27 mm and 41 mm, and a selection of peak pressures from 204 kPa to 920 kPa can be produced by selection of the driver section diameter and placement of the test sample. Characterization studies of several driver/driven section combinations showed consistent results, with peak pressures having 0.8 - 6.9 percent uncertainty in the mean. This shock tube design provides a more realistic blast profile than current air-driven shock tubes. In addition, operation does not require specialized personnel or facilities like most blast-driven...
Virtual Test Tubes: A New Methodology for Computing Max Garzon, Evan Drumwright
Deaton, Russell J.
with conventional solid-state based computers. Here, we explore an alter- native approach to exploiting and complexity, comparing it with the standard symbolic-based solid-state approach. It is becoming increasinglyVirtual Test Tubes: A New Methodology for Computing Max Garzon, Evan Drumwright Computer Science
Process for sensing defects on a smooth cylindrical interior surface in tubing
Dutton, G. Wayne (7010 Weld Co. Rd. 1, Longmont, CO 80501)
The cylindrical interior surface of small diameter metal tubing is optically inspected to determine surface roughness by passing a slightly divergent light beam to illuminate the entire interior surface of the tubing. Impingement of the input light beam components on any rough spots on the interior surface generates forward and backward scattered radiation components. The forward scattered components can be measured by blocking direct and specular radiation components exiting the tubing while allowing the forward scattered radiation to travel past the blocking location. Collecting optics are employed to converge the forward scattered radiation onto a photodetector generating a signal indicative of surface roughness. In the back scattered mode, back scattered radiation exiting the tubing through the entrance opening is reflected 90.degree. by a beam splitter towards collecting optics and a photodetector. Alternatively, back scattered radiation can be transmitted through a fiber optic bundle towards the collecting optics. The input light beam can be supplied through a white light fiber optic bundle mounted coaxial with the first bundle.
Viral Video Style: A Closer Look at Viral Videos on YouTube
Shamos, Michael I.
Viral Video Style: A Closer Look at Viral Videos on YouTube Lu Jiang, Yajie Miao, Yi Yang Introduction CMU Viral Video Dataset Statistical Characteristics Peak Day Prediction Conclusions #12;Outline Introduction CMU Viral Video Dataset Statistical Characteristics Peak Day Prediction
150K - 200K miniature pulse tube cooler for micro satellites
Chassaing, Cl�ment; Butterworth, James; Aigouy, G�rald [Air Liquide Advanced Technologies (AL-AT) - 38360 Sassenage (France); Daniel, Christophe [Centre National D'Etudes Spatiales (CNES) - 31401 Toulouse (France); Crespin, Maurice; Duvivier, Eric [STEEL �lectronique - 31220 Martres Tolosane (France)
Air Liquide is working with the CNES and Steel �lectronique in 2013 to design, manufacture and test a Miniature Pulse Tube Cooler (MPTC) to cool infrared detectors for micro-satellite missions. The cooler will be particularly adapted to the needs of the CNES MICROCARB mission to study atmospheric Carbon Dioxide which presents absorption lines in the thermal near infrared, at 1.6 ?m and 2.0 ?m. The required cooler temperature is from 150 to 200K with cooling power between 1 and 3 watts. The overall electrical power budget including electronics is less than 20W with a 288-300K rejection temperature. Particular attention is therefore paid to optimizing overall system efficiency. The active micro vibration reduction system and thermal control systems already developed for the Air Liquide Large Pulse Tube Cooler (LPTC) are currently being implemented into a new high efficiency electronic architecture. The presented work concerns the new cold finger and electronic design. The cooler uses the compressor already developed for the 80K Miniature Pulse Tube Cryocooler. This Pulse Tube Cooler addresses the requirements of space missions where extended continuous operating life time (>5 years), low mass and low micro vibration levels are critical.
IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 26, NO. 3, JUNE 1998 905 Toward "Smart Tubes" Using
-peak power microwave (HPM) tube. We use iterative learning-control (ILC) methodologies in order to control is then verified in simulation. This methodology is applicable to a wide variety of HPM sources. Index Terms. INTRODUCTION PRESENT-DAY high-peak power microwave (HPM) sources typically operate in the single-shot regime
Two-Phase Flow of Two HFC Refrigerant Mixtures Through Short Tube Orifices, Draft Final Report
Payne, W. V.; O'Neal, D. L.
The present study presents data for flow of two refrigerant mixtures through short tube orifices. The two mixtures were R3211251134a (23%/25%/52% on a mass percentage basis) and R321125 (50%/50%). The following presents results for the flow...
Focused Ion Beam Production Using a Pyroelectric Crystal and a Resistive Glass Tube
Danon, Yaron
Focused Ion Beam Production Using a Pyroelectric Crystal and a Resistive Glass Tube T. Z. Fullem, A to accelerate electrons into a metal target has led to the production of compact X-Ray generators [4], [5], [6 tungsten tip (marketed for use in a scanning electron microscope) with an apex radius of 70 nm was mounted
Analysis of Refrigerant Flow and Deformation for a Flexible Short-Tube using a Finite Element Model�
O'Neal, D.L.; Bassiouny, R.
an short-tube using a finite element model International Journal of Refrig Vol 27 No 2, pp. 176-183The short-tube is used by United States heat pump manufactures as an expansion device because of its lowAnalyse de l�e�coulement d�un frigorige`ne et...
A Numerical Estimate of Flexible Short-tube Flow and Deformation with R-134a and R-410a�
Bassiouny, R.; O'Neal, D.
-tubes as an expansion device in air condi- tioners and heat pumps. The main function of the short-tube is to control refrigerant mass flow into the evaporator. When the condenser pressure increases due to an increase in the ambient temperature above the system...
1698 IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, VOL. 18, NO. 3, SEPTEMBER 2008 Self Field Effect Compensation in an HTS Tube
Paris-Sud XI, Universit� de
Effect Compensation in an HTS Tube Bruno Douine, K�vin Berger, Jean L�v�que, Denis Netter, Olivia Arbey flux density in an HTS tube. It allows characterizing the true zero magnetic flux den- sity behaviour- sity . The characteristic is very important to calculate AC losses in superconducting wires. Indeed
Development of Friction Factor Correlation for Single-phase Flow in Micro-fin Tube Using Logistic Dose Response Curve
Ghajar, Afshin J.
in internally micro-fin tubes (see Fig.1) is important in commercial HVAC applications. It has been observed warming concerns of HVAC systems. It is commonly understood that the micro-fin enhances heat transfer on the plain tube parabolic data trend in the transition region, Ghajar and Madon [3] and Hrycak and Andrushkiw
Measurements and Predictions of the Heat Transfer at the Tube-Fin Junction for Louvered Fin Heat Exchangers
Thole, Karen A.
Measurements and Predictions of the Heat Transfer at the Tube-Fin Junction for Louvered Fin Heat Transfer at the Tube-Fin Junction for Louvered Fin Heat Exchangers Abstract The dominant thermal resistance used to increase heat transfer by initiating new boundary layer growth and increasing surface area
A pulsed eddy current probe for inspection of support plates from within Alloy-800 steam generator tubes
Krause, T. W.; Babbar, V. K.; Underhill, P. R. [Department of Physics, Royal Military College of Canada, Kingston, ON (Canada)
Support plate degradation and fouling in nuclear steam generators (SGs) can lead to SG tube corrosion and loss of efficiency. Inspection and monitoring of these conditions can be integrated with preventive maintenance programs, thereby advancing station-life management processes. A prototype pulsed eddy current (PEC) probe, targeting inspection issues associated with SG tubes in SS410 tube support plate structures, has been developed using commercial finite element (FE) software. FE modeling was used to identify appropriate driver and pickup coil configurations for optimum sensitivity to changes in gap and offset for Alloy-800 SG tubes passing through 25 mm thick SS410 support plates. Experimental measurements using a probe that was manufactured based on the modeled configuration, were used to confirm the sensitivity of differential PEC signals to changes in relative position of the tube within the tube support plate holes. Models investigated the effect of shift and tilt of tube with respect to hole centers. Near hole centers and for small shifts, modeled signal amplitudes from the differentially connected coil pairs were observed to change linearly with tube shift. This was in agreement with experimentally measured TEC coil response. The work paves the way for development of a system targeting the inspection and evaluation of support plate structures in steam generators.
Brazing open cell reticulated copper foam to stainless steel tubing with vacuum furnace brazed gold/indium alloy plating
Howard, Stanley R. (Windsor, SC); Korinko, Paul S. (Aiken, SC)
A method of fabricating a heat exchanger includes brush electroplating plated layers for a brazing alloy onto a stainless steel tube in thin layers, over a nickel strike having a 1.3 .mu.m thickness. The resultant Au-18 In composition may be applied as a first layer of indium, 1.47 .mu.m thick, and a second layer of gold, 2.54 .mu.m thick. The order of plating helps control brazing erosion. Excessive amounts of brazing material are avoided by controlling the electroplating process. The reticulated copper foam rings are interference fit to the stainless steel tube, and in contact with the plated layers. The copper foam rings, the plated layers for brazing alloy, and the stainless steel tube are heated and cooled in a vacuum furnace at controlled rates, forming a bond of the copper foam rings to the stainless steel tube that improves heat transfer between the tube and the copper foam.
Heat-rate improvements obtained by retubing condensers with new, enhanced tube types
Rabas, T.J. [Argonne National Lab., IL (United States); Taborek, J. [Consulting Services, Virginia Beach, VA (United States)
Significant fuel savings can be achieved at power plants by retubing the condensers with enhanced tubes. Because of the higher overall heat-transfer coefficient, the exhaust steam is condensed at a lower pressure and the plant efficiency is therefore increased or plant heat rate is reduced. Only the spirally indented type of enhanced tube is currently being used in the U.S. and most other countries; however, different types of enhanced tubes have been proposed for power-plant condensers, each with their own set of attributes. This paper determines what attributes and their magnitudes of enhanced tubes lead to the most energy savings as measured by reduction of the plant heat rate. The particular attributes considered are the inside and outside enhancement levels, the inside efficiency index (inside enhancement level divided by pressure-drop increase), and the enhanced-tube fouling-rate multiplier. Two particular condensers were selected because all necessary information were known from previous heat-rate studies such as the condenser geometry, the circulating-water pump and system information, and the low-pressure turbine characteristics. These are {open_quotes}real-world{close_quotes} condensers and therefore the finding will be representative for many other condenser-retubing applications. However, the authors strongly recommend that an economic evaluation be performed at each site to determine the energy savings and payback time. This generic investigation showed that the outside enhancement level is the most important attribute, and a value of about 1.5 can lead to heat-rate savings of about 20 to 40 Btu/kW-hr. Increasing the inside enhancement is less effective because of the increased pressure drop that leads to a reduction of the coolant flow rate and velocity.
For Continuous Feeding with Pump Using the CORFLO Anti-IV Feeding Tube and Extension SetFor Continuous Feeding with Pump Using the CORFLO Anti-IV Feeding Tube and Extension Set For Gravity Feeding Using the CORFLO Anti-IV Enteral Feeding TubeFor Gravity F
Kay, Mark A.
1. 3. 4. 5. 2. 5. 6. 7. 6. 7. 3. 4. For Continuous Feeding with Pump Using the CORFLO Anti-IV Feeding Tube and Extension SetFor Continuous Feeding with Pump Using the CORFLO Anti-IV Feeding Tube the instructions above for Continuous Feeding. Simply hang the syringe rather than putting it in a syringe pump
Experimental Study of Pellet Delivery to the ITER Inner Wall through a Curved Guide Tube at Steady-State Pressure
Combs, Stephen Kirk [ORNL; Baylor, Larry R [ORNL; Caughman, John B [ORNL; Fehling, Dan T [ORNL; Foust, Charles R [ORNL; Maruyama, S. [ITER International Team, Garching, Germany; McGill, James M [ORNL; Rasmussen, David A [ORNL
Injection of solid hydrogen pellets from the magnetic high-field side will be the primary technique for depositing fuel particles into the core of International Thermonuclear Experimental Reactor (ITER) burning plasmas. This injection scheme will require the use of a curved guide tube to route the pellets from the acceleration device, under the divertor, and to the inside wall launch location. In an initial series of pellet tests in support of ITER, single 5.3-mm-diam cylindrical D2 pellets were shot through a mock-up of the planned ITER curved guide tube. Those data showed that the pellet speed had to be limited to ?300 m/s for reliable delivery of intact pellets. Also, microwave cavity mass detectors located upstream and downstream of the test tube indicated that ?10% of the pellet mass was lost in the guide tube at 300 m/s. The tube base pressure for that test series was ?10-4 torr. However, for steady-state pellet fueling on ITER, the guide tube will operate at an elevated pressure due to the pellet erosion in the tube. Assuming the present design values for ITER pellet fueling rates/vacuum pumping and a 10% pellet mass loss during flight in the tube, calculations suggest a steadystate operating pressure in the range of 10-20 torr. Thus, experiments to ascertain the pellet integrity and mass loss under these conditions have been carried out. Also, some limited test data were collected at a tube pressure of ?100 torr. No significant detrimental effects have been observed at the higher tube pressures. The new test results are presented and compared to the baseline data previously reported.
Stress Analysis and Structural Optimization of a Three-Layer Composite Cladding Tube Under Thermo-Mechanical Loads
S.-S. Zhou; X.-L. Gao; G. W. Griffith
A general solution for the stress and strain fields in a three-layer composite tube subjected to internal and external pressures and temperature changes is first derived using thermo-elasticity. The material in each layer is treated as orthotropic, and the composite tube is regarded to be in a generalized plane strain state. A three-layer ZRY4-SiCf/SiCSiC composite cladding tube under a combined pressure and thermal loading is then analyzed and optimized by applying the general solution. The effects of temperature changes, applied pressures, and layer thickness on the mechanical behavior of the tube are quantitatively studied. The von Mises failure criterion for isotropic materials and the Tsai-Wu's failure theory for composites are used, respectively, to predict the failure behavior of the monolithic ZRY4 (i.e., Zircaloy-4) inner layer and SiC outer layer and the composite SiCf/SiC core layer of the three-layer tube. The numerical results reveal that the maximum radial and circumferential stresses in each layer always occur on the bonding surfaces. By adjusting the thickness of each layer, the effective stress in the three-layer cladding tube under the prescribed thermal-mechanical loading can be changed, thereby making it possible to optimally design the cladding tube.
Continuous-Wave Radar to Detect Defects Within Heat Exchangers and Steam Generator Tubes ; Revised September 3, 2003
Gary E. Rochau and Thurlow W.H. Caffey, Sandia National Laboratories, Albuquerque, NM 87185-0740; Bahram Nassersharif and Gabe V. Garcia, Department of Mechanical Engineering, New Mexico State University, Las Cruces, NM 88003-8001; Russell P. Jedlicka, Klipsch School of Electrical and Computer Engineering, New Mexico State University, Las Cruces, NM 88003-8001
OAK B204 Continuous-Wave Radar to Detect Defects Within Heat Exchangers and Steam Generator Tubes ; Revised September 3, 2003. A major cause of failures in heat exchangers and steam generators in nuclear power plants is degradation of the tubes within them. The tube failure is often caused by the development of cracks that begin on the outer surface of the tube and propagate both inwards and laterally. A new technique was researched for detection of defects using a continuous-wave radar method within metal tubing. The technique is 100% volumetric, and may find smaller defects, more rapidly, and less expensively than present methods. The project described in this report was a joint development effort between Sandia National Laboratories (SNL) and New Mexico State University (NMSU) funded by the US Department of Energy. The goal of the project was to research, design, and develop a new concept utilizing a continuous wave radar to detect defects inside metallic tubes and in particular nuclear plant steam generator tubing. The project was divided into four parallel tracks: computational modeling, experimental prototyping, thermo-mechanical design, and signal detection and analysis.
Sheared bioconvection in a horizontal tube This article has been downloaded from IOPscience. Please scroll down to see the full text article.
Bees, Martin
Sheared bioconvection in a horizontal tube This article has been downloaded from IOPscience. Please in a horizontal tube O A Croze, E E Ashraf and M A Bees Department of Mathematics, University of Glasgow, Glasgow dispersion in tubes subject to imposed flow. To optimize light and nutrient uptake, many microorganisms swim
Abbett, Bill
THE DYNAMIC EVOLUTION OF TWISTED MAGNETIC FLUX TUBES IN A THREE-DIMENSIONAL CONVECTING FLOW. II of strong downdrafts, convective flows dominate the evolution, flux tubes of any shape rapidly lose cohesion for a horizontal magnetic flux tube or layer to be preferentially transported in one vertical direction over
Effect of inlet geometries and heating on the entrance and fully-developed friction factors in the laminar and transition regions of a horizontal tube
Ghajar, Afshin J.
developed regions of a horizontal tube under different flow regimes is presented. For this purpose, accurate in the laminar and transition regions of a horizontal tube Hou Kuan Tam a , Lap Mou Tam a,b , Afshin J. Ghajar c diameter horizontal circular straight tube with square-edged and re-entrant inlets under isothermal and non
A conical mandrel tube drawing test designed to assess failure criteria. C. Linardona,b,c, D. Favierb, G. Chagnonb, B. Grueza
Paris-Sud XI, Universit� de
process. The principle of cold drawing is to reduce tube cross section and wall thickness by pullingA conical mandrel tube drawing test designed to assess failure criteria. C. Linardona,b,c, D Grenoble Alpes/CNRS/Lab3SR, BP53, 38041 Grenoble Cedex 9, France. Abstract Cold tube drawing is a metal
Shrink Tube Insulation Apparatus for Rebco Superconducting Tapes for Use in High Field Magnets
Whittington, Andrew
An increasing number of applications require the use of high temperature superconductors (HTS) such as (RE=Rare Earth) Ba2Cu3O7-x (REBCO) coated conductors [1]. HTS conductors show particularly great potential for high field magnets applications [1] due to their high upper critical fields [2], But several groups have shown that REBCO coated conductors are prone to delamination failure [3] [4] [5]. Under relatively low transverse stress the HTS film separates from the substrate and the conductor degrades [6]. This is problematic due to high transverse stresses that occur in fully epoxy impregnated solenoids wound with this conductor. Application of thin walled heat shrink tubing introduces a weak plane around the conductor, preventing delamination degradation [7]. However, manual application of the shrink tubing is impractical, requiring three operators limited to insulating 100 m lengths or less of REBCO conductor. The high risk of damage to the conductor, also associated with this process, shows the need for...
Current in a three-dimensional periodic tube with unbiased forces
Bao-quan Ai; Liang-gang Liu
Transport of a Brownian particle moving along the axis of a three-dimensional asymmetric periodic tube is investigated in the presence of asymmetric unbiased forces. The reduction of the coordinates may involve not only the appearance of entropic barrier but also the effective diffusion coefficient. It is found that in the presence of entropic barrier, the asymmetry of the tube shape and the asymmetry of the unbiased forces are the two ways of inducing a net current. The current is a peaked function of temperature which indicates that the thermal noise may facilitate the transport even in the presence of entropic barrier. There exists an optimized radius at the bottleneck at which the current takes its maximum value. Competition between the two opposite driving factors may induce current reversal.
Fundamental Kinetics Database Utilizing Shock Tube Measurements (Volumes 1, 2, 3, 4, and Volume 6)
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Davidson, D. F.; Hanson, R. K
The data from shock tube experiments generally takes three forms: ignition delay times, species concentration time-histories and reaction rate measurements. Volume 1 focuses on ignition delay time data measured and published by the Shock Tube Group in the Mechanical Engineering Department of Stanford University. The cut-off date for inclusion into this volume was January 2005. Volume 2 focuses on species concentration time-histories and was cut off December 2005. The two volumes are in PDF format and are accompanied by a zipped file of supporting data. Volume 3 was issued in 2009. Volume 4, Ignition delay times measurements came out in May, 2014, along with Reaction Rates Measurements, Vol 6. Volume 5 is not available at this time.
Controlled Thermal-Mechanical Processing of Tubes and Pipes for Enhanced Manufacturing and Performance
Kolarik, Robert V.
The Alloy Steel Business of The Timken Company won an award for the controlled thermo-mechanical processing (CTMP) project and assembled a strong international public/private partnership to execute the project. The premise of the CTMP work was to combine Timken's product understanding with its process expertise and knowledge of metallurgical and deformation fundamentals developed during the project to build a predictive process design capability. The CTMP effort succeeded in delivering a pc-based capability in the tube optimization model, with a virtual pilot plant (VPP) feature to represent the desired tube making process to predict the resultant microstructure tailored for the desired application. Additional tasks included a system for direct, online measurement of grain size and demonstration of application of CTMP via robotically enhanced manufacturing.
Intergrated function nonimaging concentrating collector tubes for solar thermal energy. Final technical report
Winston, R
A substantial improvement in optical efficiency over contemporary external reflector evacuated tube collectors has been achieved by integrating the reflector surface into the outer glass envelope. Described are the design fabrication and test results for a prototype collector based on this concept. A comprehensive test program to measure performance and operational characteristics of a 2 m/sup 2/ panel (45 tubes) has been completed. Efficiencies above 50% relative to beam at 200/sup 0/C have been repeatedly demonstrated. Both the instantaneous and long term average performance of this totally stationary solar collector are comparable to those for tracking line focus parabolic troughs. The yield, reliability and stability of performance achieved have been excellent. Subcomponent assemblies and fabrication procedures have been used which are expected to be compatible with high volume production. The collector has a wide variety of applications in the 100/sup 0/C to 300/sup 0/C range including industrial process heat, air conditioning and Rankine engine operation.
Radiative component and combined heat transfer in the thermal calculation of finned tube banks
Stehlik, P. [Technical Univ. of Brno (Czech Republic). Dept. of Process Engineering] [Technical Univ. of Brno (Czech Republic). Dept. of Process Engineering
For more exact calculation of combined heat transfer in the case of finned tube banks (e.g., in the convective section of a furnace), the radiative heat transfer cannot be neglected. A new method for relatively simple calculation of total heat flux (convection + radiation + conduction in fins) is fully compatible with that for bare tube banks/bundles developed earlier. It is based on the method of radiative coefficients. However, the resulting value of heat flux must be corrected due to fin thickness and especially due to the fin radiative influence. For this purpose the so-called multiplicator of heat flux was introduced. The applicability of this methods has been demonstrated on a tubular fired heater convective section. A developed computer program based on the method has also been used for an analysis of the influence of selected parameters to show the share of radiation on the total heat flux.
A 350 MHz, 200 kW CW, Multiple Beam Inductive Output Tube - Final Report
R.Lawrece Ives; George Collins; David Marsden Michael Read; Edward Eisen; Takuchi Kamura, Philipp Borchard
This program developed a 200 kW CW, 350 MHz, multiple beam inductive output tube (MBIOT) for driving accelerator cavities. The MBIOT operates at 30 kV with a gain of 23 dB. The estimated efficiency is 70%. The device uses seven electron beams, each transmitting 1.4 A of current. The tube is approximately six feet long and weighs approximately 400 lbs. The prototype device will be evaluated as a potential RF source for the Advanced Photon Source at Argonne National Laboratory (ANL). Because of issues related to delivery of the electron guns, it was not possible to complete assembly and test of the MBIOT during the Phase II program. The device is being completed with support from Calabazas Creek Research, Inc., Communications & Power Industries, LLC. and the Naval Surface Weapons Center (NSWC) in Dahlgren, VA. The MBIOT will be initially tested at NSWC before delivery to ANL. The testing at NSWC is scheduled for February 2013.
The Entropy of Attention and Popularity in YouTube Videos
Morgan, Jonathan Scott; Lampe, Cliff; Radha, Hayder
The vast majority of YouTube videos never become popular, languishing in obscurity with few views, no likes, and no comments. We use information theoretical measures based on entropy to examine how time series distributions of common measures of popularity in videos from YouTube's "Trending videos" and "Most recent" video feeds relate to the theoretical concept of attention. While most of the videos in the "Most recent" feed are never popular, some 20% of them have distributions of attention metrics and measures of entropy that are similar to distributions for "Trending videos". We analyze how the 20% of "Most recent" videos that become somewhat popular differ from the 80% that do not, then compare these popular "Most recent" videos to different subsets of "Trending videos" to try to characterize and compare the attention each receives.
Cracking and Corrosion of Composite Tubes in Black Liquor Recovery Boiler Primary Air Ports
Keiser, James R.; Singbeil, Douglas L.; Sarma, Gorti B.; Kish, Joseph R.; Yuan, Jerry; Frederick, Laurie A.; Choudhury, Kimberly A.; Gorog, J. Peter; Jett�, Francois R.; Hubbard, Camden R.; Swindeman, Robert W.; Singh, Prett M.; Maziasz, Phillip J.
Black liquor recovery boilers are an essential part of kraft mills. Their design and operating procedures have changed over time with the goal of providing improved boiler performance. These performance improvements are frequently associated with an increase in heat flux and/or operating temperature with a subsequent increase in the demand on structural materials associated with operation at higher temperatures and/or in more corrosive environments. Improvements in structural materials have therefore been required. In most cases the alternate materials have provided acceptable solutions. However, in some cases the alternate materials have solved the original problem but introduced new issues. This report addresses the performance of materials in the tubes forming primary air port openings and, particularly, the problems associated with use of stainless steel clad carbon steel tubes and the solutions that have been identified.
Assessment of CCFL model of RELAP5/MOD3 against simple vertical tubes and rod bundle tests. International Agreement Report
Cho, S.; Arne, N. [Korea Electric Power Corp., Taejon (KR). Research Center; Chung, B.D.; Kim, H.J. [Korea Inst. of Nuclear Safety, Taejon (KR)
The CCFL model used in RELAP5/MOD3 version 5m5 has been assessed against simple vertical tubes and bundle tests performed at a facility of Korea Atomic Energy Research Institute. The effect of changes in tube diameter and nodalization of tube section were investigated. The roles of interfacial drags on the flooding characteristics are discussed. Differences between the calculation and the experiment are also discussed. A comparison between model assessment results and the test data showed that the calculated value lay well on the experimental flooding curve specified by user, but the pressure jump before onset of flooding was not calculated.
Calculation of dose rates during replacement of the 3CL seal tube in the FFTF IEM cell
Nelson, J.V.
In September 1996, the seal tube at the 3CL window of the Interim Examination and Maintenance (IEM) Cell at the Fast Flux Test Facility (FFTF) failed. Replacement of the seal tube required removing the 3CL master slave manipulator (MSM) and shielding creating a streaming path for radiation from irradiated fuel and activated hardware in the IEM Cell. As a part of the preparation for the seal tube replacement, expected dose rates in the IEM Cell gallery outside the open 3CL penetration during the repair work were evaluated.
Thermal performance testing of two Thales 9310 pulse-tube cryocoolers for PHyTIR
Paine, Christopher G. [Jet Propulsion Laboratory, California Institute of Technology 4800 Oak Grove Drive, Pasadena CA 91109 (United States)
PHyTIR is a NASA-funded technology demonstration for a near-term earth-observing instrument in the thermal infrared spectrum, intended for use in the HyspIRI mission. PHyTIR will use two Thales 9310 single-stage pulse tube cryocoolers, one to directly cool the FPA, the other to simulate a passive radiator. We report performance measurements for the two Thales 9310 cryocoolers intended for inclusion in the PHyTIR demonstrator.
Combustor with two stage primary fuel tube with concentric members and flow regulating
Parker, David Marchant (Oviedo, FL); Whidden, Graydon Lane (Orlando, FL); Zolyomi, Wendel (Lawrenceville, GA)
A combustor for a gas turbine having a centrally located fuel nozzle and inner, middle and outer concentric cylindrical liners, the inner liner enclosing a primary combustion zone. The combustor has an air inlet that forms two passages for pre-mixing primary fuel and air to be supplied to the primary combustion zone. Each of the pre-mixing passages has a circumferential array of swirl vanes. A plurality of primary fuel tube assemblies extend through both pre-mixing passages, with each primary fuel tube assembly located between a pair of swirl vanes. Each primary fuel tube assembly is comprised of two tubular members. The first member supplies fuel to the first pre-mixing passage, while the second member, which extends through the first member, supplies fuel to the second pre-mixing passage. An annular fuel manifold is divided into first and second chambers by a circumferentially extending baffle. The proximal end of the first member is attached to the manifold itself while the proximal end of the second member is attached to the baffle. The distal end of the first member is attached directly to the second member at around its mid-point. The inlets of the first and second members are in flow communication with the first and second manifold chambers, respectively. Control valves separately regulate the flow of fuel to the two chambers and, therefore, to the two members of the fuel tube assemblies, thereby allowing the flow of fuel to the first and second pre-mixing passages to be separately controlled.
Eddy current inspection of power plant heat-exchanger tubing in the USA
Fishkin, P.; Nash, J. [MQS Inspection, Inc., Chicago, IL (United States)
The latest experience in the eddy current inspection of heat-exchanger tubing by means of ID probes is reported and generalized. The authors demonstrate the feasibility of using modern, general-purpose, digital eddy current flaw detectors equipped with microprocessors, displays, the capability for recording inspection results on paper or magnetic media, sound and visual alarms. The NDE personnel qualification and certification requirements are described.
Loss of feed flow, steam generator tube rupture and steam line break thermohydraulic experiments
Mendler, O J; Takeuchi, K; Young, M Y
The Westinghouse Model Boiler No. 2 (MB-2) steam generator test model at the Engineering Test Facility in Tampa, Florida, was reinstrumented and modified for performing a series of tests simulating steam generator accident transients. The transients simulated were: loss of feed flow, steam generator tube rupture, and steam line break events. This document presents a description of (1) the model boiler and the associated test facility, (2) the tests performed, and (3) the analyses of the test results.
Kayshap, P.; Srivastava, Abhishek K. [Aryabhatta Research Institute of Observational Sciences (ARIES), Manora Peak, Nainital 263129 (India); Murawski, K. [Group of Astrophysics, UMCS, ul. Radziszewskiego 10, 20-031 Lublin (Poland); Tripathi, Durgesh, E-mail: firstname.lastname@example.com, E-mail: firstname.lastname@example.com, E-mail: firstname.lastname@example.com, E-mail: email@example.com [Inter-University Centre for Astrophysics, Post Bag 4, Ganeshkhind, Pune 411007 (India)
We report an observation of a small-scale flux tube that undergoes kinking and triggers the macrospicule and a jet on 2010 November 11 in the north polar corona. The small-scale flux tube emerged well before the triggering of the macrospicule and as time progresses the two opposite halves of this omega-shaped flux tube bent transversely and approach each other. After {approx}2 minutes, the two approaching halves of the kinked flux tube touch each other and an internal reconnection as well as an energy release takes place at the adjoining location and a macrospicule was launched which goes up to a height of 12 Mm. Plasma begins to move horizontally as well as vertically upward along with the onset of the macrospicule and thereafter converts into a large-scale jet in which the core denser plasma reaches up to {approx}40 Mm in the solar atmosphere with a projected speed of {approx}95 km s{sup -1}. The fainter and decelerating plasma chunks of this jet were also seen up to {approx}60 Mm. We perform a two-dimensional numerical simulation by considering the VAL-C initial atmospheric conditions to understand the physical scenario of the observed macrospicule and associated jet. The simulation results show that reconnection-generated velocity pulse in the lower solar atmosphere steepens into slow shock and the cool plasma is driven behind it in the form of macrospicule. The horizontal surface waves also appeared with shock fronts at different heights, which most likely drove and spread the large-scale jet associated with the macrospicule.
Sensing system for detection and control of deposition on pendant tubes in recovery and power boilers
Kychakoff, George (Maple Valley, WA); Afromowitz, Martin A. (Mercer Island, WA); Hogle, Richard E. (Olympia, WA)
A system for detection and control of deposition on pendant tubes in recovery and power boilers includes one or more deposit monitoring sensors operating in infrared regions of about 4 or 8.7 microns and directly producing images of the interior of the boiler, or producing feeding signals to a data processing system for information to enable a distributed control system by which the boilers are operated to operate said boilers more efficiently. The data processing system includes an image pre-processing circuit in which a 2-D image formed by the video data input is captured, and includes a low pass filter for performing noise filtering of said video input. It also includes an image compensation system for array compensation to correct for pixel variation and dead cells, etc., and for correcting geometric distortion. An image segmentation module receives a cleaned image from the image pre-processing circuit for separating the image of the recovery boiler interior into background, pendant tubes, and deposition. It also accomplishes thresholding/clustering on gray scale/texture and makes morphological transforms to smooth regions, and identifies regions by connected components. An image-understanding unit receives a segmented image sent from the image segmentation module and matches derived regions to a 3-D model of said boiler. It derives a 3-D structure the deposition on pendant tubes in the boiler and provides the information about deposits to the plant distributed control system for more efficient operation of the plant pendant tube cleaning and operating systems.
Survey for Intergeneric Pollen Tube Growth in Intergeneric Pollinations Utilizing the iap Allele in Sorghum bicolor
Bartek, Matthew Scott
Grow...th in the pistils of S. bicolor accessions Tx3361 and ATx623?....... 39 Fig. 3. Miscanthus floridulus (PI 230189) pollen tube growth in the pistils of S. bicolor accessions Tx3361 and ATx623??????.............. 40 1 INTRODUCTION... officinarum L.) and pearl millet [Pennisetum glaucum (L.) R. Br.] are just a few of the species that make this sub-family so vital to our existence (Giussani et al., 2001). Taxonomic classifications within Poaceae were constructed using morphological...
Fischer-Tropsch studies with catalyst-sprayed tube wall reactors
Zarochak, M.F.; Pennline, H.W.; Schehl, R.R.
A summary of Fischer-Tropsch studies in bench-scale tube wall reactors using flame-sprayed catalysts is presented. Preliminary studies were conducted with various flame-sprayed catalysts, after which taconite was chosen as the prime candidate for more extensive evaluation. Results from several life tests with promoted and unpromoted taconite are reported, along with a data base that discusses the effects of various process variables on catalyst activity and product selectivity.
Asymmetry of H{sub {beta}} Stark profiles in T-tube hydrogen plasma
Djurovic, S.; Nikolic, D.; Savic, I.; Soerge, S.; Demura, A. V. [Faculty of Science, Department of Physics, Trg Dositeja Obradovica 4, 21000 Novi Sad (Serbia and Montenegro); Bereich Stellaratortheorie, Max-Planck-Instituet fuer Plasmaphysik, Teilinstitut Greifswald, Wendelsteinstrasse 1, D-17491 Greifswald (Germany); HEPTI, RRC Kurchatov Institute, Kurchatov Square 1, Moscow 123182 (Russian Federation)
The whole Balmer H{sub {beta}} line profiles are studied in detail experimentally in the T-tube discharge for the wide range of plasma parameters. Besides the common one, two additional parameters are introduced to characterize the asymmetry behavior of the experimental Stark profiles with the reference point chosen in the center of the line. The experimental data are analyzed and benchmarked versus the simple theoretical model based on the effects of microfield nonuniformity and electron impact shifts.
Gelles, David S.
Two further failed thermal creep pressurized tubes of V-4Cr-4Ti tested at 700 and 800 degrees C have been examined using optical microscopy and transmission electron microscopy in order to understand failure and creep mechanisms. These conditions represent lower stress states than were previously examined. Creep deformation at lower stress is shown to be controlled by sub-boundary formation and mis-orientation between sub-grains arising from climb of dislocations within the boundary.
An investigation of effects of flow conditioning on straight tube Coriolis meter
Shukla, Shashank
metering can be very beneficial for the following1, 2. 1.1.1 Layout of production facilities Use of multiphase meters reduces the hardware needed for onshore, offshore topside and offshore subsea applications by eliminating the need of dedicated test... Coriolis meters are essentially aeroelastic devices; and as such involve coupled dynamic interaction of fluid dynamics and structural system. The Coriolis meter basically consists of a tube conveying fluid (lying in one plane and clamped at its ends...
Effect of oxide films on hydrogen permeability of candidate Stirling heater head tube alloys
Schuon, S R; Misencik, J A
High pressure hydrogen has been selected as the working fluid for the developmental automotive Stirling engine. Containment of the working fluid during operation of the engine at high temperatures and at high hydrogen gas pressures is essential for the acceptance of the Stirling engine as an alternative to the internal combustion engine. Most commercial alloys are extremely permeable to pure hydrogen at high temperatures. A program was undertaken at NASA Lewis Research Center (LeRC) to reduce hydrogen permeability in the Stirling engine heater head tubes by doping the hydrogen working fluid with CO or CO/sub 2/. Small additions of these gases were shown to form an oxide on the inside tube wall and thus reduce hydrogen permeability. A study of the effects of dopant concentration, alloy composition, and effects of surface oxides on hydrogen permeability in candidate heater head tube alloys is summarized. Results showed that hydrogen permeability was similar for iron-base alloys (N-155, A286, IN800, 19-9DL, and Nitronic 40), cobalt-base alloys (HS-188) and nickel-base alloys (IN718). In general, the permeability of the alloys decreased with increasing concentration of CO or CO/sub 2/ dopant, with increasing oxide thickness, and decreasing oxide porosity. At high levels of dopants, highly permeable liquid oxides formed on those alloys with greater than 50% Fe content. Furthermore, highly reactive minor alloying elements (Ti, Al, Nb, and La) had a strong influence on reducing hydrogen permeability.
A focused liquid jet formed by a water hammer in a test tube
Kiyama, Akihito; Ando, Keita; Kameda, Masaharu
We investigate motion of a gas-liquid interface in a test tube induced by a large acceleration via impulsive force. We conduct simple experiments in which the tube partially filled with a liquid falls under gravity and impacts a rigid floor. A curved gas-liquid interface inside the tube reverses and eventually forms an elongated jet (i.e. the so-called a focused jet). In our experiments, there arises either vibration of the interface or increment in the velocity of a liquid jet accompanied by the onset of cavitation in the liquid column. These phenomena cannot be explained by considering pressure impulse in a classical potential flow analysis, which does not account for finite speeds of sound as well as phase change. Here we model such water-hammer events as a result of one-dimensional pressure wave propagation and its interaction with boundaries through acoustic impedance mismatching. The method of characteristics is applied to describe pressure wave interactions and the subsequent cavitation. The proposed m...
Characterization of Bead Trajectories Through the Draft Tube of a Turbine Physical Model.
Weiland, Mark A.; Mueller, Robert P.; Carlson, Thomas J.; Deng, Zhiquan; McKinstry, Craig A.
Using high-speed video imaging, trajectories, and kinematics of beads passing below the turbine runner and through the draft tube region of the 1:25 scale model of a single turbine unit from Bonneville Dam powerhouse 1 were collected from May 6-9, 2003 at U.S. Army Corps of Engineers (USACE) Environmental Research and Development Center (ERDC) in Vicksburg, MS. An individual camera was used to produce 2-dimensional trajectories and paired cameras with overlapping fields of view were used to produce 3-dimension trajectories of near neutrally buoyant beads as they passed through the draft tube region of the turbine model. Image data was collected at two turbine operating levels, lower 1% efficiency and maximum rated output for beads released mid-depth into the turbine intake from each of the three gatewell slots. The purpose of this study was to determine the feasibility of using video imaging to track the trajectories of beads through the draft tube of turbine physical models and from the trajectories calculate the kinematics of the bead trajectory and the beads response to turbulence in the model. This project is part of a research program supported by the U.S. Department of Energy Advanced Hydropower Turbine System Program (AHTS) who's goal is to increase the operating potential of hydroelectric facilities while also reducing the reducing the risk of injury and death to fish as they pass through the turbines.
Routh, S. [Department of Physics, R. V. College of Engineering, Bangalore (India)] [Department of Physics, R. V. College of Engineering, Bangalore (India); Musielak, Z. E. [Department of Physics, University of Texas at Arlington, Arlington, TX 76019 (United States)] [Department of Physics, University of Texas at Arlington, Arlington, TX 76019 (United States); Hammer, R., E-mail: email@example.com, E-mail: firstname.lastname@example.com, E-mail: email@example.com [Kiepenheuer-Institut fuer Sonnenphysik, Schoeneckstr. 6, Freiburg, D-79104 Germany (Germany)
It is a well-established result that the propagation of linear transverse waves along a thin but isothermal magnetic flux tube is affected by the existence of the global cutoff frequency, which separates the propagating and non-propagating waves. In this paper, the wave propagation along a thin and non-isothermal flux tube is considered and a local cutoff frequency is derived. The effects of different temperature profiles on this local cutoff frequency are studied by considering different power-law temperature distributions, as well as the semi-empirical VAL C model of the solar atmosphere. The obtained results show that the conditions for wave propagation strongly depend on the temperature gradients. Moreover, the local cutoff frequency calculated for the VAL C model gives constraints on the range of wave frequencies that are propagating in different parts of the solar atmosphere. These theoretically predicted constraints are compared to observational data and are used to discuss the role played by transverse tube waves in the atmospheric heating and dynamics, and in the excitation of solar atmospheric oscillations.
Torsional Alfven Waves in Solar Magnetic Flux Tubes of Axial Symmetry
Murawski, K; Musielak, Z E; Srivastava, A K; Kraskiewicz, J
Aims: Propagation and energy transfer of torsional Alfv\\'en waves in solar magnetic flux tubes of axial symmetry is studied. Methods: An analytical model of a solar magnetic flux tube of axial symmetry is developed by specifying a magnetic flux and deriving general analytical formulae for the equilibrium mass density and a gas pressure. The main advantage of this model is that it can be easily adopted to any axisymmetric magnetic structure. The model is used to simulate numerically the propagation of nonlinear Alfv\\'en waves in such 2D flux tubes of axial symmetry embedded in the solar atmosphere. The waves are excited by a localized pulse in the azimuthal component of velocity and launched at the top of the solar photosphere, and they propagate through the solar chromosphere, transition region, and into the solar corona. Results: The results of our numerical simulations reveal a complex scenario of twisted magnetic field lines and flows associated with torsional Alfv\\'en waves as well as energy transfer to t...
SeZnSb alloy and its nano tubes, graphene composites properties
Singh, Abhay Kumar [Department of Physics, Indian Institute of Physics, Bangalore-560012 (India)
Composite can alter the individual element physical property, could be useful to define the specific use of the material. Therefore, work demonstrates the synthesis of a new composition Se{sub 96}-Zn{sub 2}-Sb{sub 2} and its composites with 0.05% multi-walled carbon nano tubes and 0.05% bilayer graphene, in the glassy form. The diffused amorphous structure of the multi walled carbon nano tubes and bilayer gaphene in the Se{sub 96}-Zn{sub 2}-Sb{sub 2} alloy have been analyzed by using the Raman, X-ray photoluminescence spectroscopy, Furrier transmission infrared spectra, photoluminescence, UV/visible absorption spectroscopic measurements. The diffused prime Raman bands (G and D) have been appeared for the multi walled carbon nano tubes and graphene composites, while the X-ray photoluminescence core energy levels peak shifts have been observed for the composite materials. Subsequently the photoluminescence property at room temperature and a drastic enhancement (upto 80%) in infrared transmission percentage has been obtained for the bilayer graphene composite, along with optical energy band gaps for these materials have been evaluated 1.37, 1.39 and 1.41 eV.
Operational control and maintenance integrity of typical and atypical coil tube steam generating systems
Beardwood, E.S.
Coil tube steam generators are low water volume to boiler horsepower (bhp) rating, rapid steaming units which occupy substantially less space per boiler horsepower than equivalent conventional tire tube and water tube boilers. These units can be retrofitted into existing steam systems with relative ease and are more efficient than the generators they replace. During the early 1970's they became a popular choice for steam generation in commercial, institutional and light to medium industrial applications. Although these boiler designs do not require skilled or certified operators, an appreciation for a number of the operational conditions that result in lower unscheduled maintenance, increased reliability and availability cycles would be beneficial to facility owners, managers, and operators. Conditions which afford lower operating and maintenance costs will be discussed from a practical point of view. An overview of boiler design and operation is also included. Pitfalls are provided for operational and idle conditions. Water treatment application, as well as steam system operations not conducive to maintaining long term system integrity; with resolutions, will be addressed.
Status Report on Studies of Recovery Boiler Composite Floor Tube Cracking
Eng, P.; Frederick, L.A.; Hoffmann, C.M.; Keiser, J.R.; Mahmood, J.; Maziasz, P.J.; Prescott, R.; Sarma, G.B.; Singbeil, D.L.; Singh, P.M.; Swindeman, R.W.; Wang, X.-L.
Cracking of the stainless steel layer of co-extruded 304L stainless steel/SA210 Gd A 1 carbon steel black liquor recovery boiler floor tubes has been identified as one of the most serious material problems in the pulp and paper industry. A DOE-funded study was initiated in 1995 with the goal of determining the cause of and possible solutions to this cracking problem. These studies have characterized tube cracking as well as the chemical and thermal environment and stress state of floor tubes. Investigations of possible cracking mechanisms indicate that stress corrosion cracking rather than thermal fatigue is a more likely cause of crack initiation. The cracking mechanism appears to require the presence of hydrated sodium sulfide and is most likely active during shut-downs and/or start-ups. Based on these results and operating experience, certain alloys appear to be more resistant than others to cracking in the floor environment, and certain operating practices appear to significantly lessen the likelihood of cracking. This report is the latest in a series of progress reports presented on this project.
Sabau, Adrian S [ORNL; Wright, Ian G [ORNL; Shingledecker, John P. [Electric Power Research Institute (EPRI)
This paper provides an introduction to a comprehensive model being developed to predict and control oxide scale exfoliation from the steam-side of superheater and reheater tubes in steam boilers. The model deals with the main phenomena involved in scale growth and failure in steam, and incorporates major variables related to boiler design and operation. The considerations used to calculate oxide growth under the specific constrains of small diameter tubes carrying high-pressure steam and operating with large temperature gradients under temperature and pressure cycling conditions, as well as the evolution of stresses and strains in the scales, are indicated but only a cursory description is given of the details of the analytical treatments. An example is presented of calculations made with the model to predict the extent of blockage expected in a single superheater loop as a function of time and outlet steam temperature under several realistic service conditions. The results suggest that problems due to scale exfoliation would be expected early in the operating life of superheater tubes made from austenitic steel TP347H.
LUCID A Cherenkov Tube Based Detector for Monitoring the ATLAS Experiment Luminosity
Sbrizzi, A
The LUCID (LUminosity Cherenkov Integrating Detector) apparatus is composed by two symmetric arms deployed at about 17 m from the ATLAS interaction point. The purpose of this detector, which will be installed in january 2008, is to monitor the luminosity delivered by the LHC machine to the ATLAS experiment. An absolute luminosity calibration is needed and it will be provided by a Roman Pot type detector with the two arms placed at about 240 m from the interaction point. Each arm of the LUCID detector is based on an aluminum vessel containing 20 Cherenkov tubes, 15 mm diameter and 1500 mm length, filled with C4F10 radiator gas at 1.5 bar. The Cherenkov light generated by charged particles above the threshold is collected by photomultiplier tubes (PMT) directly placed at the tubes end. The challenging aspect of this detector is its readout in an environment characterized by the high dose of radiation (about 0.7 Mrad/year at 10^33cm^2 s^-1) it must withstand. In order to fulfill these radiation hardness requirem...
High Pressure Shock Tube Studies of Fuel Combustion Engineering The high-pressure single-pulse shock tube is shown in Figure 8 (rated at 5 to 1000 atm,
Ben-Arie, Jezekiel
High Pressure Shock Tube Studies of Fuel Combustion Engineering The high-pressure single and oxidative degradation of various components in order to identify the products as guides to the combustion
Robert Radtke; David Glowka; Man Mohan Rai; David Conroy; Tim Beaton; Rocky Seale; Joseph Hanna; Smith Neyrfor; Homer Robertson
Commercial introduction of Microhole Technology to the gas and oil drilling industry requires an effective downhole drive mechanism which operates efficiently at relatively high RPM and low bit weight for delivering efficient power to the special high RPM drill bit for ensuring both high penetration rate and long bit life. This project entails developing and testing a more efficient 2-7/8 in. diameter Turbodrill and a novel 4-1/8 in. diameter drill bit for drilling with coiled tubing. The high-power Turbodrill were developed to deliver efficient power, and the more durable drill bit employed high-temperature cutters that can more effectively drill hard and abrasive rock. This project teams Schlumberger Smith Neyrfor and Smith Bits, and NASA AMES Research Center with Technology International, Inc (TII), to deliver a downhole, hydraulically-driven power unit, matched with a custom drill bit designed to drill 4-1/8 in. boreholes with a purpose-built coiled tubing rig. The U.S. Department of Energy National Energy Technology Laboratory has funded Technology International Inc. Houston, Texas to develop a higher power Turbodrill and drill bit for use in drilling with a coiled tubing unit. This project entails developing and testing an effective downhole drive mechanism and a novel drill bit for drilling 'microholes' with coiled tubing. The new higher power Turbodrill is shorter, delivers power more efficiently, operates at relatively high revolutions per minute, and requires low weight on bit. The more durable thermally stable diamond drill bit employs high-temperature TSP (thermally stable) diamond cutters that can more effectively drill hard and abrasive rock. Expectations are that widespread adoption of microhole technology could spawn a wave of 'infill development' drilling of wells spaced between existing wells, which could tap potentially billions of barrels of bypassed oil at shallow depths in mature producing areas. At the same time, microhole coiled tube drilling offers the opportunity to dramatically cut producers' exploration risk to a level comparable to that of drilling development wells. Together, such efforts hold great promise for economically recovering a sizeable portion of the estimated remaining shallow (less than 5,000 feet subsurface) oil resource in the United States. The DOE estimates this U.S. targeted shallow resource at 218 billion barrels. Furthermore, the smaller 'footprint' of the lightweight rigs utilized for microhole drilling and the accompanying reduced drilling waste disposal volumes offer the bonus of added environmental benefits. DOE analysis shows that microhole technology has the potential to cut exploratory drilling costs by at least a third and to slash development drilling costs in half.
Design of a single orifice pulse tube refrigerator through the development of a first-order model
Schor, Alisha R. (Alisha Robin)
A first order model for the behavior of a linear orifice pulse tube refrigerator (OPTR) was developed as a design tool for construction of actual OPTRs. The model predicts cooling power as well as the pressure/volume ...
Analysis/control of in-bed tube erosion phenomena in the fluidized bed combustion system. Final technical report
Lee, Seong W.
Research is presented on erosion and corrosion of fluidized bed combustor component materials. The characteristics of erosion of in-bed tubes was investigated. Anti-corrosion measures were also evaluated.
Partial SOP for Tube Anneal Furnace, EML: 9/04 Instructions for temp controller for Anneal furnace
Reif, Rafael
Partial SOP for Tube Anneal Furnace, EML: 9/04 Instructions for temp controller for Anneal furnace the "C" clamp. Take the ceramic and quartz end caps off. 2. Load your samples into a quartz boat. Load
Fluid-elastic Instability of Helical Tubes Subjected to Single-Phase External Flow and Two-Phase Internal Flow
Jong Chull Jo; Myung Jo Jhung; Woong Sik Kim; Hho Jung Kim [Korea Institute of Nuclear Safety, 19 Kusung-dong, Yusung-gu, Taejon 305-338 (Korea, Republic of)
This study investigates the fluid-elastic instability characteristics of steam generator helical type tubes in operating nuclear power plants. The thermal-hydraulic conditions of both tube side and shell side flow fields are predicted by a general purpose computational fluid dynamics code employing the finite volume element modeling. To get the natural frequency, corresponding mode shape and participation factor, modal analyses are performed for helical type tubes with various conditions. Investigated are the effects of the helix angle, the number of supports and the status of the inner fluid on the modal, and fluid-elastic instability characteristics of the tubes, which are expressed in terms of the natural frequency, corresponding mode shape, and stability ratio. (authors)
All-glass vacuum tube collector heat transfer model used in forced-circulation solar water heating system
Li, Zhiyong; Chen, Chao; Luo, Hailiang; Zhang, Ye; Xue, Yaning [College of Architecture and Civil Engineering, Beijing University of Technology, Beijing (China)
The aim of this paper is to establish the heat transfer model of all-glass vacuum tube collector used in forced-circulation solar water heating system. In this model, the simplified heat transfer of collector is composed of the natural convection in single glass tube and forced flow in manifold header. Thus the heat balance equation of water in single tube and the heat balance equation of water in manifold header have been established. The flow equation is also built by analyzing the friction and buoyancy in tube. Through solved these equations the relationship between the collector average temperature, the outlet temperature and natural convection flow rate have been obtained. From this relationship and energy balance equation of collector, the collector outlet temperature can be calculated. The validated experiments of this model were carried out in winter of Beijing. (author)
Film boiling on the inside of vertical tubes with upward flow of the fluid at low qualities
Dougall, R. S.
Flow regimes, local heat transfer coefficients, and temperature distributions along the wall have been studied for film boiling inside a vertical tube with upward flow of a saturated liquid. The area of interest has been ...
Decontamination and dismantlement of the building 200/205 pneumatic transfer tube at Argonne National Laboratory-East project final report.
Wiese, E. C.
The Building 200/205 Pneumatic Transfer Tube D&D Project was directed toward the following goals: Remove any radioactive and hazardous materials associated with the transfer tube; Survey the transfer tube to identify any external contamination; Remove the transfer tube and package for disposal; Survey the soil and sand surrounding the transfer tube for any contamination; and Backfill the trench in which the tube sat and restore the area to its original condition. These goals had been set in order to eliminate the radiological and hazardous safety concerns inherent in the buried transfer tube and to allow, upon completion of the project, the removal of this project from the ANL-E action item list. The physical condition of the transfer tube and possible nuclear fuel samples lost in the tube were the primary areas of concern, while the exact location of the transfer tube was of secondary concern. ANL-E health physics technicians collected characterization data from the ends of the Building 200/205 pneumatic transfer tube in January 1998. The characterization surveys identified contamination to a level of 67,000 dpm (1,117 Bq) ({beta}/{gamma}) and 20,000 dpm (333 Bq) {alpha} smearable at the opening.
The effect of silica gel sampling tube design on the analytical recovery of fluorine ions / by Daniel Howard Anna�
Anna, Daniel Howard
THE EFFECT OF SILICA GEL SAMPLING TUBE DESIGN ON THE ANALYTICAL RECOVERY OF FLUORINE IONS A Thesis by DANIEL HOWARD ANNA Submitted to the Office of Graduate Studies of Texas ARM University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE August 1991 Major Subject: Industrial Hygiene THE EFFECI' OF SILICA GEL SAMPLING TUBE DESIGN ON THE ANALYTICAL RECOVERY OF FLUORINE IONS A Thesis by DANIEL HOWARD ANNA Approved as to style and content by: Ri rd B. n...
An Experimental Study into the Ignition of Methane and Ethane Blends in a New Shock-tube Facility
Aul, Christopher Joseph Erik
the reflected shock wave Abbreviations BP backing pump for driven section DP driver pump for driver section GRI Gas Research Institute NTC negative temperature coefficient PT pressure transducer RCM rapid compression machine RMS root-mean square RP....................................................................................................................................98 xi LIST OF FIGURES Page Figure 1. Shock-tube diagram outlining traditional gas dynamic effects ...................... 3? Figure 2. Shock tube facility with two available configurations shown ........................ 9? Figure 3...
The effect of silica gel sampling tube design on the analytical recovery of fluorine ions / by Daniel Howard Anna
Anna, Daniel Howard
THE EFFECT OF SILICA GEL SAMPLING TUBE DESIGN ON THE ANALYTICAL RECOVERY OF FLUORINE IONS A Thesis by DANIEL HOWARD ANNA Submitted to the Office of Graduate Studies of Texas ARM University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE August 1991 Major Subject: Industrial Hygiene THE EFFECI' OF SILICA GEL SAMPLING TUBE DESIGN ON THE ANALYTICAL RECOVERY OF FLUORINE IONS A Thesis by DANIEL HOWARD ANNA Approved as to style and content by: Ri rd B. n...
Evaluation on double-wall-tube residual stress distribution of sodium-heated steam generator by neutron diffraction and numerical analysis
Kisohara, N. [Advanced Nuclear System Research and Development Directorate, Japan Atomic Energy Agency (Japan); Suzuki, H.; Akita, K. [Quantum Beam Science Directorate, Japan Atomic Energy Agency (Japan); Kasahara, N. [Dept. of Nuclear Engineering and Management, Univ. of Tokyo (Japan)
A double-wall-tube is nominated for the steam generator heat transfer tube of future sodium fast reactors (SFRs) in Japan, to decrease the possibility of sodium/water reaction. The double-wall-tube consists of an inner tube and an outer tube, and they are mechanically contacted to keep the heat transfer of the interface between the inner and outer tubes by their residual stress. During long term SG operation, the contact stress at the interface gradually falls down due to stress relaxation. This phenomenon might increase the thermal resistance of the interface and degrade the tube heat transfer performance. The contact stress relaxation can be predicted by numerical analysis, and the analysis requires the data of the initial residual stress distributions in the tubes. However, unclear initial residual stress distributions prevent precious relaxation evaluation. In order to resolve this issue, a neutron diffraction method was employed to reveal the tri-axial (radius, hoop and longitudinal) initial residual stress distributions in the double-wall-tube. Strain gauges also were used to evaluate the contact stress. The measurement results were analyzed using a JAEA's structural computer code to determine the initial residual stress distributions. Based on the stress distributions, the structural computer code has predicted the transition of the relaxation and the decrease of the contact stress. The radial and longitudinal temperature distributions in the tubes were input to the structural analysis model. Since the radial thermal expansion difference between the inner (colder) and outer (hotter) tube reduces the contact stress and the tube inside steam pressure contributes to increasing it, the analytical model also took these effects into consideration. It has been conduced that the inner and outer tubes are contacted with sufficient stresses during the plant life time, and that effective heat transfer degradation dose not occur in the double-wall-tube SG. (authors)
Columbia University flow instability experimental program: Volume 7. Single tube tests, critical heat flux test program
Dougherty, T.; Maciuca, C.; McAssey, E.V. Jr.; Reddy, D.G.; Yang, B.W.
This report deals with critical heat flux (CHF) measurements in vertical down flow of water at low pressures in a round Inconel tube, 96 inches long and 0.62 inch inside diameter. A total of 28 CHF points were obtained. These data were found to correlate linearly with the single variable q, defined as the heat flux required to raise the enthalpy from the inlet value to the saturation value. These results were compared to the published results of Swedish investigators for vertical upflow of water at low pressures in round tubes of similar diameters and various lengths. The parameter q depends on the inlet enthalpy and is a nonlocal variable, thus this correlation is nonlocal unless the coefficients depend upon tube length in a particular prescribed manner. For the low pressure Swedish data, the coefficients are practically independent of length and hence the correlation is nonlocal. In the present investigation only one length was employed, so it is not possible to determine whether the correlation for these data is local or nonlocal, although there is reason to believe that it is local. The same correlation was applied to a large data base (thousands of CHF points) compiled from the published data of a number of groups and found to apply, with reasonable accuracy over a wide range of conditions, yielding sometimes local and sometimes nonlocal correlations. The basic philosophy of data analysis here was not to generate a single correlation which would reproduce all data, but to search for correlations which apply adequately over some range and which might have some mechanistic significance. The tentative conclusion is that at least two mechanisms appear operative, leading to two types of correlations, one local, the other nonlocal.
Bacellar, Daniel [University of Maryland, College Park; Ling, Jiazhen [University of Maryland, College Park; Aute, Vikrant [University of Maryland, College Park; Radermacher, Reinhard [University of Maryland, College Park; Abdelaziz, Omar [ORNL
Air-to-refrigerant heat exchangers are very common in air-conditioning, heat pump and refrigeration applications. In these heat exchangers, there is a great benefit in terms of size, weight, refrigerant charge and heat transfer coefficient, by moving from conventional channel sizes (~ 9mm) to smaller channel sizes (< 5mm). This work investigates new designs for air-to-refrigerant heat exchangers with tube outer diameter ranging from 0.5 to 2.0mm. The goal of this research is to develop and optimize the design of these heat exchangers and compare their performance with existing state of the art designs. The air-side performance of various tube bundle configurations are analyzed using a Parallel Parameterized CFD (PPCFD) technique. PPCFD allows for fast-parametric CFD analyses of various geometries with topology change. Approximation techniques drastically reduce the number of CFD evaluations required during optimization. Maximum Entropy Design method is used for sampling and Kriging method is used for metamodeling. Metamodels are developed for the air-side heat transfer coefficients and pressure drop as a function of tube-bundle dimensions and air velocity. The metamodels are then integrated with an air-to-refrigerant heat exchanger design code. This integration allows a multi-scale analysis of air-side performance heat exchangers including air-to-refrigerant heat transfer and phase change. Overall optimization is carried out using a multi-objective genetic algorithm. The optimal designs found can exhibit 50 percent size reduction, 75 percent decrease in air side pressure drop and doubled air heat transfer coefficients compared to a high performance compact micro channel heat exchanger with same capacity and flow rates.
Final Technical Report - High-Performance, Oxide-Dispersion-Strengthened Tubes for Production of Ethylene adn Other Industrial Chemicals
McKimpson, Marvin G.
This project was undertaken by Michigan Technological University and Special Metals Corporation to develop creep-resistant, coking-resistant oxide-dispersion-strengthened (ODS) tubes for use in industrial-scale ethylene pyrolysis and steam methane reforming operations. Ethylene pyrolysis tubes are exposed to some of the most severe service conditions for metallic materials found anywhere in the chemical process industries, including elevated temperatures, oxidizing atmospheres and high carbon potentials. During service, hard deposits of carbon (coke) build up on the inner wall of the tube, reducing heat transfer and restricting the flow of the hydrocarbon feedstocks. About every 20 to 60 days, the reactor must be taken off-line and decoked by burning out the accumulated carbon. This decoking costs on the order of $9 million per year per ethylene plant, accelerates tube degradation, and requires that tubes be replaced about every 5 years. The technology developed under this program seeks to reduce the energy and economic cost of coking by creating novel bimetallic tubes offering a combination of improved coking resistance, creep resistance and fabricability not available in current single-alloy tubes. The inner core of this tube consists of Incoloy(R) MA956, a commercial ferritic Fe-Cr-Al alloy offering a 50% reduction in coke buildup combined with improved carburization resistance. The outer sheath consists of a new material - oxide dispersion strengthened (ODS) Alloy 803(R) developed under the program. This new alloy retains the good fireside environmental resistance of Alloy 803, a commercial wrought alloy currently used for ethylene production, and provides an austenitic casing to alleviate the inherently-limited fabricability of the ferritic Incoloy(R) MA956 core. To provide mechanical compatibility between the two alloys and maximize creep resistance of the bimetallic tube, both the inner Incoloy(R) MA956 and the outer ODS Alloy 803 are oxide dispersion strengthened materials produced using mechanical alloying technology. To minimize cost, the bimetallic tube is produced by direct powder co-extrusion. This technology has potential for domestic energy savings of up to 4.1 trillion BTU/year (4.3 x 1015J/year) and a reduction of 370,000 tons (340,000 tonnes) of CO2 emissions in short-residence-time ethylene furnaces. This represents an energy savings and CO2 emissions reduction of about 3.3%. If the technology is also applied to other types of ethylene pyrolysis furnaces, total energy savings and CO2 emissions reductions could increase by up to five times. The work involved: Developing powder and consolidation processing protocols to produce an oxide-dispersion strengthened variant of Alloy 803 exhibiting creep strength comparable to Incoloy? Alloy MA956, Developing a direct powder co-extrusion protocol for fabricating co-extruded bimetallic Incoloy? Alloy MA956 / ODS Alloy 803 tubes, Characterizing the properties of the ODS Alloy 803 material, the welding characteristics of the bimetallic tubes, and the coking characteristics of the Incoloy? MA956 alloy, and Documenting the potential energy savings and user requirements for these bimetallic pyrolysis furnace tubes. The project demonstrated that oxide dispersion strengthened Alloy 803 can be produced successfully using conventional mechanical alloying technology. The oxide dispersion strengthened bimetallic radiant coil technology explored under this program has significant potential for energy savings and productivity improvements for domestic ethylene producers. In today's competitive market, however, domestic furnace manufacturers and ethylene producers appear reluctant to pay any cost premium for higher-performance coil materials offering either higher temperature capabilities or longer service life. Interest in oxide dispersion strengthened radiant coils is likely to increase if furnace and ethylene producers begin to focus more on increasing tube wall temperatures to improve productivity.
Numerical Simulation of PulseTube Refrigerators: 1D model I.A. Lyulina 1 , R.M.M. Mattheij 1 , A.S. Tijsseling 1 , A.T.A.M. de Waele 2
Eindhoven, Technische Universiteit
Numerical Simulation of Pulse�Tube Refrigerators: 1D model I.A. Lyulina 1 , R.M.M. Mattheij 1 , A of a pulse�tube refrigerator. Conservation equations describing compressible gas flow in the tube are solved, calculate the average enthalpy flow and estimate the refrigeration power. Keywords: pulse�tube refrigerator
Fractal tube formulas and a Minkowski measurability criterion for compact subsets of Euclidean spaces
Michel L. Lapidus; Goran Radunovi?; Darko �ubrini?
We establish pointwise and distributional fractal tube formulas for a large class of compact subsets of Euclidean spaces of arbitrary dimensions. These formulas are expressed as sums of residues of suitable meromorphic functions over the complex dimensions of the compact set under consideration (i.e., over the poles of its fractal zeta function). Our results generalize to higher dimensions (and in a significant way) the corresponding ones previously obtained for fractal strings by the first author and van Frankenhuijsen. They are illustrated by several examples and applied to yield a new Minkowski measurability criterion.
A study of the precursor effect in an arc-driven shock tube
Reed, James Alan
A STUDY OF THE PRECURSOR EFFECT IN AN ARC-DRIVEN SHOCK TISE A Thesis by JAMES ALAN REED Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May 1969 Major... Subject: Aerospace Engineering A STUDY OF THE PRECURSOR EFFECT IN AN ARC-DRIVEN SHOCK TUBE A Thesis by JAMES ALAN REED Approved as to style and content by: (Chairman of Committee) (He p ) (Member) (Memb er) (Member) (Member) (Member) 11ay 1969...
A probabilistic method for leak-before-break analysis of CANDU reactor pressure tubes
Puls, M.P.; Wilkins, B.J.S.; Rigby, G.L. [Whiteshell Labs., Pinawa (Canada)] [and others
A probabilistic code for the prediction of the cumulative probability of pressure tube ruptures in CANDU type reactors is described. Ruptures are assumed to result from the axial growth by delayed hydride cracking. The BLOOM code models the major phenomena that affect crack length and critical crack length during the reactor sequence of events following the first indications of leakage. BLOOM can be used to develop unit-specific estimates of the actual probability of pressure rupture in operating CANDU reactors and supplement the existing leak before break analysis.
New tube bundle heat transfer correlations and flow regime maps for a Once Through Steam Generator�
Blanchat, Thomas Kevin
Support Group for their many helpful discussions and comments throughout this project. I would like to thank Mr. Richard Wagner at EGgrG, Idaho, for his patient explanations of the mechanics of the RELAP5/MOD2 code which enabled me to perform the code... completed which allow the user to input the pitch and tube o. d. for the system. Predicted RELAP5/MOD2 heat transfer coefficients from correlations have been reviewed for single phase liquid convection, subcooled, and saturated nu- cleate boiling...
Optical spectroscopy of quantum confined states in GaAs/AlGaAs quantum well tubes
Shi, Teng; Fickenscher, Melodie; Smith, Leigh; Jackson, Howard [Department of Physics, University of Cincinnati, Cincinnati, OH 45221 (United States); Yarrison-Rice, Jan [Department of Physics, Miami University, Oxford, OH 45056 (United States); Gao, Qiang; Tan, Hoe; Jagadish, Chennupati [Department of Electronic Materials and Engineering, Australian National University, Canberra, ACT 0200 (Australia); Etheridge, Joanne [Monash Centre for Electron Microscopy, Monash University, Victoria, 3800 (Australia); Wong, Bryan M. [Materials Chemistry Department, Sandia National Laboratories, Livermore, CA 94551 (United States)
We have investigated the quantum confinement of electronic states in GaAs/Al{sub x}Ga{sub 1?x}As nanowire heterostructures which contain radial GaAs quantum wells of either 4nm or 8nm. Photoluminescence and photoluminescence excitation spectroscopy are performed on single nanowires. We observed emission and excitation of electron and hole confined states. Numerical calculations of the quantum confined states using the detailed structural information on the quantum well tubes show excellent agreement with these optical results.
Heat Transfer Characteristics of Sulfur and Sulfur Diluted with Hydrogen Sulfide Flowing Through Circular Tubes
Stone, Porter Walwyn
concentrations of hydrogen sulfide, using water as a basis of comparison. For identical tube sizes and the same fluid velocity, both pure and dilute sulfur were found to have a film conductance ~- I less than ten percent that of water over most... the v x d curves for each concentration of diluent. Sulfur is diluted with H2S, added as persulfide Sulfur is diluted with H S, added as liquid 34 35 10. A Ratio of film conductance of pure sulfur to that of water versus temperature. The flow...
Standard practice for dissolution of UF6 from P-10 tubes
American Society for Testing and Materials. Philadelphia
1.1 This practice covers the dissolution of UF6 from a P-10 tube to provide solutions for analysis. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific safeguard and safety precaution statements, see Section 8.
Influence of the gas-flow Reynolds number on a plasma column in a glass tube
Jin, Dong Jun; Uhm, Han S.; Cho, Guangsup [Department of Electronic and Biological Physics, Kwangwoon University, 20 Kwangwon-Ro, Nowon-Gu, Seoul 139-701 (Korea, Republic of)] [Department of Electronic and Biological Physics, Kwangwoon University, 20 Kwangwon-Ro, Nowon-Gu, Seoul 139-701 (Korea, Republic of)
Atmospheric-plasma generation inside a glass tube is influenced by gas stream behavior as described by the Reynolds number (Rn). In experiments with He, Ne, and Ar, the plasma column length increases with an increase in the gas flow rate under laminar flow characterized by Rn < 2000. The length of the plasma column decreases as the flow rate increases in the transition region of 2000 < Rn < 4000. For a turbulent flow beyond Rn > 4000, the length of the plasma column is short in front of the electrode, eventually leading to a shutdown.
A system for calibration of long term sampling with toluene detector tubes
Yalcinkaya, Ayse Perihan
is 9 the catalized reaction of some gaseous contaminants with each other arising from the closer molecular contact provided by the active sur- face of the substrate in the detector tube. B Since in most cases, a fixed volume of air sample... in magnitude compared to the other error sources in diffusion cells. 29 The temperature dependence of the diffusion coefficient is expressed as n D2 T2 Pl ? =( ? ) Dl Tl P2 (6) 2 where 0 and D are diffusion coefficients in ? at room temperatures cm 1...
Integrating a Traveling Wave Tube into an AECR-U ion source
Covo, Michel Kireeff; Benitez, Janilee Y.; Ratti, Alessandro; Vujic, Jasmina L.
An RF system of 500W - 10.75 to 12.75 GHz was designed and integrated into the Advanced Electron Cyclotron Resonance - Upgrade (AECR-U) ion source of the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory. The AECR-U produces ion beams for the Cyclotron giving large flexibility of ion species and charge states. The broadband frequency of a Traveling Wave Tube (TWT) allows modifying the volume that couples and heats the plasma. The TWT system design and integration with the AECR-U ion source and results from commissioning are presented.
WG-MOX Fuel Zr-tube Neutron Spectrum Comparison in ATR and PWR
Gray S. Chang
An experiment containing WG-MOX fuel has been designed and irradiated from 1998 to 2004 in the Advanced Test Reactor (ATR) at the Idaho National Engineering and Environmental Laboratory (INEEL). Important neutronics parameters were computed using novel Monte Carlo methods. The purpose of this summary is to compare the Weapons-Grade Mixed Oxide fuel (WG-MOX) Zr-tube�s neutron spectrum in ATR and PWR. The results indicate that the Zrtube�s neutron spectrum in ATR are softer than in PWR.
Operational experience with compressed geometry acceleration tubes in the Oak Ridge 25URC tandem accelerator
Jones, C.M.; Haynes, D.L.; Juras, R.C.; Meigs, M.J.; Ziegler, N.F.
Installation of compressed geometry acceleration tubes and other associated modifications have increased the effective voltage capability of the Oak Ridge 25URC tandem accelerator by about 3 MV. Since mid-September 1988, the accelerator has been operated routinely at terminal potentials up to 24 MV and occasionally near 25 MV. In 3500 hours of full-column operation, including 1100 hours at potentials about 22 MV, no significant spark-included damage was observed. Some considerations related to further improvements in voltage performance are discussed. 7 refs., 5 figs.
U-Tube Steam Generator experiments: steady state and transients analysis using RELAP5/MOD2
Kalyanasundaram, Mathangi
model of westinghouse Model Boiler Vo. 2 (%1B-2) test facility steam generator. 2. Perforni sensitivdty studies on the nodalization of the RELAP5 niodel of the steam generator 3. Determine the best model for the steam generator based... on the sensitivity studies. Such a model will be a. representation of a Westinghouse E-tube steam generator. It will be represented by hydrorlynamic volunies, junctions. and flow area. s. 4. Obtain steady state results using RELAP5/MOD2 code for MB-2 steam gen...
High efficiency, low frequency linear compressor proposed for Gifford-McMahon and pulse tube cryocoolers
H�hne, Jens [Pressure Wave Systems GmbH, H�berlstr. 8, 80337 Munich (Germany)
In order to reduce the amount of greenhouse gas emissions, which are most likely the cause of substantial global warming, a reduction of overall energy consumption is crucial. Low frequency Gifford-McMahon and pulse tube cryocoolers are usually powered by a scroll compressor together with a rotary valve. It has been theoretically shown that the efficiency losses within the rotary valve can be close to 50%{sup 1}. In order to eliminate these losses we propose to use a low frequency linear compressor, which directly generates the pressure wave without using a rotary valve. First results of this development will be presented.
Flux tubes in the SU(3) vacuum: London penetration depth and coherence length
Paolo Cea; Leonardo Cosmai; Francesca Cuteri; Alessandro Papa
Within the dual superconductor scenario for the QCD confining vacuum, the chromoelectric field generated by a static $q\\overline{q}$ pair can be fitted by a function derived, by dual analogy, from a simple variational model for the magnitude of the normalized order parameter of an isolated Abrikosov vortex. Previous results for the SU(3) vacuum are revisited, but here the transverse chromoelectric field is measured by means of the connected correlator of two Polyakov loops and, in order to reduce noise, the smearing procedure is used instead of cooling. The penetration and coherence lengths of the flux tube are then extracted from the fit and compared with previous results.
Investigation of Q-tubes stability using the piecewise parabolic potential
E. Nugaev; A. Shkerin
We analyze the classical stability of Q-tubes --- charged extended objects in $(3+1)$-dimensional complex scalar field theory. Explicit solutions were found analytically in the piecewise parabolic potential. Our choice of potential allows us to construct a powerful method of stability investigation. We check that in the case of the zero winding number $n=0$, the previously known stability condition $\\partial^2E/\\partial Q^21$ becomes unstable towards the decay into the $n$ vortices with the single winding number.
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'Nano'tubes, Surface Area & NanoSolar Cells | Department of Energy
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: The Future of Bad CholesteroliManage#AskEnergySaver: LEDEDTSaving'Nano'tubes,
Effects of the difference in tube voltage of the CT scanner on dose calculation
Rhee, Dong Joo; Moon, Young Min; Kim, Jung Ki; Jeong, Dong Hyeok
Computed Tomography (CT) measures the attenuation coefficient of an object and converts the value assigned to each voxel into a CT number. In radiation therapy, CT number, which is directly proportional to the linear attenuation coefficient, is required to be converted to electron density for radiation dose calculation for cancer treatment. However, if various tube voltages were applied to take the patient CT image without applying the specific CT number to electron density conversion curve, the accuracy of dose calculation would be unassured. In this study, changes in CT numbers for different materials due to change in tube voltage were demonstrated and the dose calculation errors in percentage depth dose (PDD) and a clinical case were analyzed. The maximum dose difference in PDD from TPS dose calculation and Monte Carlo simulation were 1.3 % and 1.1 % respectively when applying the same CT number to electron density conversion curve to the 80 kVp and 140 kVp images. In the clinical case, the different CT nu...
Evaluation of candidate stirling engine heater tube alloys for 1000 hours at 760/sup 0/C
Misencik, J.A.
Six tubing alloys were endurance tested in a diesel-fired, Stirling engine simulator materials test rig for 1000 hours at 760/sup 0/C while pressurized at 17 to 21 MPa with either hydrogen or helium. The alloys tested were N-155, A-286, Incoloy 800, 19-9DL, Nitronic 40, and 316 stainless steel. All alloys were in the form of tubing with an outside diameter of 4.8 mm and a wall thickness of 0.8 mm. Hydrogen permeated rapidly through the walls of all six alloys when they were heated to 760/sup 0/C, and repressurization was required every 5 hours during rig testing. In contrast, helium was readily contained. Creep-rupture failures occurred in four of the six alloys pressurized with heluim and in two of the six alloys pressurized with hydrogen. Only two alloys survived the 1000-h endurance test with no failure, N-155 and 316 stainless steel. Stimulaneous exposure to either hydrogen or helium and the combustion environment at 21 MPa and 760/sup 0/C did not seriously degrade the tensile strength of the six alloys in tests at room temperature and 760/sup 0/C after exposure. Decreases in room-temperature ductility were noted and are attributed to aging rather than to hydrogen embrittlement or oxidation in three of the alloys. However, there may be a hydrogen embrittlement effect in the N-155, 19-9DL, and Nitronic 40 alloys.
The Autoignition of iso-Cetane: Shock Tube Experiments and Kinetic Modeling
Oehlschlaeger, M A; Steinberg, J; Westbrook, C K; Pitz, W J
Iso-cetane (2,2,4,4,6,8,8-heptamethylnonane, C{sub 16}H{sub 34}) is a highly branched alkane reference compound for determining cetane ratings. It is also a candidate branched alkane representative in surrogate mixtures for diesel and jet fuels. Here new experiments and kinetic modeling results are presented for the autoignition of iso-cetane at elevated temperatures and pressures relevant to combustion in internal combustion engines. Ignition delay time measurements were made in reflected shock experiments in a heated shock tube for {Phi} = 0.5 and 1.0 iso-cetane/air mixtures at temperatures ranging from 953 to 1347 K and pressures from 8 to 47 atm. Ignition delay times were measured using electronically excited OH emission, monitored through the shock tube end wall, and piezoelectric pressure transducer measurements, made at side wall locations. A new kinetic mechanism for the description of the oxidation of iso-cetane is presented that is developed based on a previous mechanism for iso-octane. Computed results from the mechanism are found in good agreement with the experimental measurements. To our knowledge, the ignition time measurements and detailed kinetic mechanism for isocetane presented here are the first of their kind.
Nuclear reactor fuel assembly duct-tube-to-handling-socket attachment system
Christiansen, David W. (Kennewick, WA); Smith, Bob G. (Kennewick, WA)
A reusable system for removably attaching the upper end 10of a nuclear reactor duct tube to the lower end 30 of a nuclear reactor fuel assembly handling socket. A transition ring 20, fixed to the duct tube's upper end 10, has an interior-threaded section 22 with a first locking hole segment 24. An adaptor ring 40, fixed to the handling socket's lower end 30 has an outside-threaded section 42 with a second locking hole segment 44. The inside 22 and outside 42 threaded sections match and can be joined so that the first 24 and second 44 locking hole segments can be aligned to form a locking hole. A locking ring 50, with a locking pin 52, slides over the adaptor ring 40 so that the locking pin 52 fits in the locking hole. A swage lock 60 or a cantilever finger lock 70 is formed from the locking cup collar 26 to fit in a matching groove 54 or 56 in the locking ring 50 to prevent the locking ring's locking pin 52 from backing out of the locking hole.
Analysis of buoyancy and tube rotation relative to the modified chemical vapor deposition process
Choi, M.; Lin, Y.T.; Greif, R. (Univ. of California, Berkeley (USA))
The secondary flows resulting from buoyancy effects in respect to the MCVD process have been studied in a rotating horizontal tube using a perturbation analysis. The three-dimensional secondary flow fields have been determined at several axial locations in a tube whose temperature varies in both the axial and circumferential directions for different rotational speeds. For small rotational speeds, buoyancy and axial convection are dominant and the secondary flow patterns are different in the regions near and far from the torch. For moderate rotational speeds, the effects of buoyancy, axial and angular convection are all important in the region far from the torch where there is a spiraling secondary flow. For large rotational speeds, only buoyancy and angular convection effects are important and no spiraling secondary motions occurs far downstream. Compared with thermophoresis, the important role of buoyancy in determining particle trajectories in MCVD is presented. As the rotational speed increases, the importance of the secondary flow decreases and the thermophoretic contribution vecomes more important. It is noted that thermophoresis is considered to be the main cause of particle deposition in the MCVD process.