Sample records for corrugated pipe culverts

  1. Lower San Fernando corrugated metal pipe failure

    SciTech Connect

    Bardet, J.P. [Univ. of Southern California, Los Angeles, CA (United States); Davis, C.A. [Los Angeles Dept. of Water and Power, CA (United States)

    1995-12-31

    During the January 17, 1994, Northridge earthquake, a 2.4 m diameter corrugated metal pipe was subjected to 90 m of extensive lateral crushing failure at the Lower San Fernando Dam. The dam and outlet works were reconstructed after the 1971 San Fernando Earthquake. In 1994, the dam underwent liquefaction upstream of the reconstructed berm. The pipe collapsed on the west side of the liquefied zone and a large sinkhole formed over the drain line. The failure of this drain line provides a unique opportunity to study the seismic response of buried drains and culverts.

  2. Turbulent Open-Channel Flow in Circular Corrugated Culverts

    Microsoft Academic Search

    S. A. Ead; N. Rajaratnam; C. Katopodis; F. Ade

    2000-01-01

    This paper presents the results of a laboratory study of the velocity field in turbulent open-channel flow in a circular corrugated pipe of diameter D of 0.622 m for three slopes S of 0.55, 1.14, and 2.55% and a range of discharges from 30 to 200 L\\/s. The Manning n was found to be equal to 0.023. Velocities were relatively

  3. Safe end treatments for roadside drainage culverts 

    E-print Network

    Jackson, Benito

    1980-01-01

    treatments for roadside cross- drainage culverts. This thesis describes a full-scale crash test program conducted to arr1ve at the largest clear opening and maximum safety grate spacing on a culvert end that could be safely traversed by an out...-of-control vehicle. The culvert installations tested were a corrugated metal pipe culvert and a concrete box culvert. Tests were conducted in accordance with nationally recognized test procedures, and the results were eval- uated based on the impact performance...

  4. Corrugated Pipe as a Beam Dechirper

    SciTech Connect

    Bane, K.L.F.; Stupakov, G.; /SLAC

    2012-04-20

    We have studied the use of a metallic pipe with small corrugations for the purpose of passively dechirping, through its wakefield, a short, intense electron bunch. The corrugated pipe is attractive for this purpose because its wake: (i) has near maximal possible amplitude for a given aperture and (ii) has a relatively large oscillation wave length, even when the aperture is small. We showed how the corrugated structure can satisfy dechirping requirements encountered in the NGLS project at LBNL. We found that a linear chirp of -40 MeV/mm can be induced by an NGLS-like beam, by having it pass through a corrugated, metallic pipe of radius 3 mm, length 8.2 m, and corrugation parameters full depth 450 {mu}m and period 1000 {mu}m. This structure is about 15 times as effective in the role of dechirper as an S-band accelerator structure used passively.

  5. ROAD CULVERTS ACROSS STREAMS WITH THE ENDANGERED TOPEKA SHINER, NOTROPIS TOPEKA, IN THE JAMES, VERMILLION, AND BIG SIOUX RIVER BASINS

    Microsoft Academic Search

    Steven S. Wall; Charles R. Berry

    We evaluated 232 installed corrugated pipe culverts at 81 sites where roads cross streams that have a high potential for Topeka shiner presence. Culvert con- ditions were characterized by the amount of perching, embeddedness, blockage, gradient and water velocity, and rated for potential as a barrier to upstream fish migration. Seven sites were classified as high priority for maintenance or

  6. Terahertz Radiation from a Pipe with Small Corrugations

    SciTech Connect

    Bane, K.L.F.; Stupakov, G.; /SLAC

    2012-01-26

    We have studied through analytical and numerical methods the use of a relativistic electron bunch to drive a metallic beam pipe with small corrugations for the purpose of generating terahertz radiation. For the case of a pipe with dimensions that do not change along its length, we have shown that - with reasonable parameters - one can generate a narrow-band radiation pulse with frequency {approx}1 THz, and total energy of a few milli-Joules. The pulse length tends to be on the order of tens of picoseconds. We have also shown that, if the pipe radius is tapered along its length, the generated pulse will end up with a frequency chirp; if the pulse is then made to pass through a compressor, its final length can be reduced to a few picoseconds and its peak power increased to 1 GW. We have also shown that wall losses tend to be significant and need to be included in the structure design.

  7. Surface Impedance Formalism for a Metallic Beam Pipe with Small Corrugations

    SciTech Connect

    Stupakov, G.; Bane, K.L.F.; /SLAC

    2012-08-30

    A metallic pipe with wall corrugations is of special interest in light of recent proposals to use such a pipe for the generation of terahertz radiation and for energy dechirping of electron bunches in free electron lasers. In this paper we calculate the surface impedance of a corrugated metal wall and show that it can be reduced to that of a thin layer with dielectric constant {epsilon} and magnetic permeability {mu}. We develop a technique for the calculation of these constants, given the geometrical parameters of the corrugations. We then calculate, for the specific case of a round metallic pipe with small corrugations, the frequency and strength of the resonant mode excited by a relativistic beam. Our analytical results are compared with numerical simulations, and are shown to agree well.

  8. On whistling of pipes with a corrugated segment: Experiment and theory

    NASA Astrophysics Data System (ADS)

    Rudenko, Oleksii; Nakibo?lu, Güne?; Holten, Ad; Hirschberg, Avraham

    2013-12-01

    Corrugated pipes are commonly used because of their local rigidity combined with global flexibility. The flow through such a pipe can induce strong whistling tones, which is an environmental nuisance and can be a threat to the mechanical integrity of the system. This paper considers the use of a composite pipe: a shorter corrugated pipe segment embedded between smooth pipe segments. Such a pipe retains some flexibility, while the acoustical damping in the smooth pipe reduces whistling tones. Whistling is the result of coherent vortex shedding at the cavities in the wall. This vortex shedding is synchronized by longitudinal acoustic waves traveling along the pipe. The acoustic waves trigger the vortex shedding, which reinforces the acoustic field for a critical range of the Strouhal number values. A linear theory for plane wave propagation and the sound production is proposed, which allows a prediction of the Mach number at the threshold of whistling in such pipes. A semi-empirical approach is chosen to determine the sound source in this model. This source corresponds to a fluctuating force acting on the fluid as a consequence of the vortex shedding. The functional form of the Strouhal number dependency of the dimensionless sound source amplitude is based on numerical simulations. The magnitude of the source and the Strouhal number range in which it can drive whistling are determined by matching the model to results for a specific corrugated pipe segment length. This semi-empirical source model is then applied to composite pipes with different corrugated segment lengths. In addition, the effect of inlet acoustical convective losses due to flow separation is considered. The Mach number at the threshold of whistling is predicted within a factor 2.

  9. Impedance of Beam Pipes with Smooth Shallow Corrugations

    E-print Network

    roughness. At present different models have been developed by K.Bane, C.Ng, A.Chao [1], G.Stupakov [2], A.Novokhatski, M.Timm, T.Weiland [3] to study the effect of a random surface roughness in a beam pipe, and by K.Bane

  10. Response of reinforced concrete and corrugated steel pipes to surface load

    NASA Astrophysics Data System (ADS)

    Lay, Geoff R.

    Full-scale simulated live load tests were conducted in a controlled laboratory setting using a single-axle frame on 600-mm-inner-diameter reinforced concrete pipe (RCP) and corrugated steel pipe (CSP) when buried in dense, well-graded sand and gravel. Measurements of the RCP at nominal and working forces and beyond are reported for 0.3, 0.6 and 0.9 m of soil cover above the pipe crown. The RCP experienced no cracking when buried at 0.3 m under nominal and working CL-625 and CL-800 single-axle design loads. At these loads, the vertical contraction of the pipe diameter was less than 0.08 and 0.10 mm and the largest tensile strains in the pipe were 75 and 100 muepsilon (50-60% of the cracking strain), respectively. A 0.15 (+/-0.05)-mm-wide axial crack developed at the inner crown in the presence of a 6 kNm/m circumferential bending moment (70% of the theoretical ultimate moment capacity) at the fully factored CL-625 load. This crack did not propagate or widen from 3 series of cyclic load-unload tests. At 1300 kN of applied load the change in pipe diameter was less than 3.5 mm. Increasing soil cover from 0.3 to 0.6 to 0.9 m reduced the circumferential crown bending moment from 6.0 to 3.9 to 2.1 kNm/m, respectively, at 400 kN of axle load. A 1.6- and a 2.8-mm-thick CSP were also subjected to axle loading. No yielding or limit states occurred in the 1.6-mm-thick CSP when buried 0.9-m-deep. However, at 0.6 m of cover a 300 kN axle load caused local yielding at the pipe crown. Increasing soil cover from 0.6 to 0.9 m decreased the vertical diameter change from -3.0 to -1.2 mm and the crown bending moment from 0.7 to 0.2 kNm/m (75% and 20% of the yield moment), respectively, at a 250 kN axle load. Deflections of the thicker CSP were less than the thinner pipe below the CL-625 single-axle load, however further increases in applied load produced a greater response in the thicker pipe, likely due to a haunch support issue. Shallow axle loading produced a greater 3-dimensional response and a larger bending effect in both CSPs.

  11. 1. View east at west facade of culvert outlet headwall, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. View east at west facade of culvert outlet headwall, above which part of the canal bank has been removed. Foreground to background: streambed and coffer dam (mound in center) that was used in dewatering the culvert; intake pipes (extreme left and right) for dewatering pumps; deteriorated culvert outlet headwall with upper portion of wall fallen away; horizontal masonry cutoff wall extending above the culvert outlet partially up the canal bank (cutoff wall was exposed by removal of part of canal bank); towpath at top of canal bank. - Delaware & Raritan Canal, Six Mile Run Culvert, .2 mile South of Blackwells Mills Road, East Millstone, Somerset County, NJ

  12. 7. VIEW OF A DOUBLE CULVERT IN RAILROAD GRADE, LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. VIEW OF A DOUBLE CULVERT IN RAILROAD GRADE, LOOKING WEST. THIS CULVERT HAS BEEN IN PLACE SINCE 1933, WHEN IT WAS MARKED ON MONTANA DEPARTMENT OF HIGHWAYS AS-BUILT PLANS. IT LOOKS LIKE THE PIPE ON THE RIGHT (NORTH) IS NOT ORIGINAL. - Great Northern Railroad Bed, From Big Sandy to Verona, Fort Benton, Chouteau County, MT

  13. Experimental demonstration of energy-chirp control in relativistic electron bunches using a corrugated pipe.

    PubMed

    Emma, P; Venturini, M; Bane, K L F; Stupakov, G; Kang, H-S; Chae, M S; Hong, J; Min, C-K; Yang, H; Ha, T; Lee, W W; Park, C D; Park, S J; Ko, I S

    2014-01-24

    The first experimental study is presented of a corrugated wall device that uses wakefields to remove a linear energy correlation in a relativistic electron beam (a "dechirper"). Time-resolved measurements of both longitudinal and transverse wakefields of the device are presented and compared with simulations. This study demonstrates the feasibility to employ a dechirper for precise control of the beam phase space in the next generation of free-electron-lasers. PMID:24484143

  14. Culvert No. 1308, High Germany Road Culvert in Little Orleans, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Culvert No. 1308, High Germany Road Culvert in Little Orleans, Maryland. Bill's Place in foreground, looking east. - Western Maryland Railway, Cumberland Extension, Pearre to North Branch, from WM milepost 125 to 160, Pearre, Washington County, MD

  15. Application of a multistate model to estimate culvert effects on movement of small fishes

    USGS Publications Warehouse

    Norman, J.R.; Hagler, M.M.; Freeman, Mary C.; Freeman, B.J.

    2009-01-01

    While it is widely acknowledged that culverted road-stream crossings may impede fish passage, effects of culverts on movement of nongame and small-bodied fishes have not been extensively studied and studies generally have not accounted for spatial variation in capture probabilities. We estimated probabilities for upstream and downstream movement of small (30-120 mm standard length) benthic and water column fishes across stream reaches with and without culverts at four road-stream crossings over a 4-6-week period. Movement and reach-specific capture probabilities were estimated using multistate capture-recapture models. Although none of the culverts were complete barriers to passage, only a bottomless-box culvert appeared to permit unrestricted upstream and downstream movements by benthic fishes based on model estimates of movement probabilities. At two box culverts that were perched above the water surface at base flow, observed movements were limited to water column fishes and to intervals when runoff from storm events raised water levels above the perched level. Only a single fish was observed to move through a partially embedded pipe culvert. Estimates for probabilities of movement over distances equal to at least the length of one culvert were low (e.g., generally ???0.03, estimated for 1-2-week intervals) and had wide 95% confidence intervals as a consequence of few observed movements to nonadjacent reaches. Estimates of capture probabilities varied among reaches by a factor of 2 to over 10, illustrating the importance of accounting for spatially variable capture rates when estimating movement probabilities with capture-recapture data. Longer-term studies are needed to evaluate temporal variability in stream fish passage at culverts (e.g., in relation to streamflow variability) and to thereby better quantify the degree of population fragmentation caused by road-stream crossings with culverts. ?? American Fisheries Society 2009.

  16. Acoustical studies on corrugated tubes

    NASA Astrophysics Data System (ADS)

    Balaguru, Rajavel

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

  17. ECOLOGICAL CRITERIA FOR PRIORITIZATION OF CULVERT REPLACEMENT

    EPA Science Inventory

    Culvert passage issues are gaining national and international focus, because they are implicated in the decline of particular species and in the more general loss of biodiversity in freshwater ecosystems. In the Pacific Northwest, inadequate fish passage at culverts is recognized...

  18. Culvert Testing Program for Juvenile Salmonid Passage

    SciTech Connect

    Pearson, Walter H. (BATTELLE (PACIFIC NW LAB)); Richmond, Marshall C. (BATTELLE (PACIFIC NW LAB)); Schafer, Jim (Washington State Department of Transportation)

    2002-01-01

    In partnership with the Washington State Department of Transportation (WSDOT), the Pacific Northwest National Laboratory (PNNL) has undertaken a phased program conducted by an interdisciplinary team of experts to address the hydraulic and behavioral issues associated with juvenile salmonid fish passage through culvert systems. Juvenile coho salmon (Oncorhynchus kisutch) is the initial test subject. This program addresses the testing and assessment of culvert designs, along with associated measurements of hydraulic conditions and fish behavior, occurring in full-scale physical models of culvert systems deployed in an experimental test bed. The proposed approach includes the use of three kinds of models. First, a conceptual model of fish passage is developed to guide the design of hydraulic and behavioral testing and to interpret the results. Second, mathematical models of culvert hydraulics provide information to design the full-scale test facility and to guide design of the hydraulic a nd behavioral testing program. Third, full-scale physical models of culverts in a test bed are used to evaluate fish passage quantitatively. Using the knowledge and data from previous studies, this program will encompass the design, fabrication, installation, and operation of a full-scale, controlled culvert test bed. Experiments in the testing apparatus will measure the hydraulic conditions (mean velocity, turbulence, and water depth) associated with various culvert designs under various slopes and flow regimes and then relate these measures to repeatable, quantitative measures of fish passage success. After construction in late spring, 2001, preliminary trials will be conducted in summer 2001.

  19. 3. View southwest at dewatered culvert outlet headwall, with part ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. View southwest at dewatered culvert outlet headwall, with part of canal bank removed in back (left) of headwall. - Delaware & Raritan Canal, Ten Mile Run Culvert, 1.5 miles South of Blackwells Road, East Millstone, Somerset County, NJ

  20. 4. View southeast at culvert outlet with part of the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. View southeast at culvert outlet with part of the canal bank removed. Right to left: dewatered streambed and coffer dam; tops of culvert barrels and curved wingwalls exposed; horizontal masonry cutoff wall partially up the canal bank. - Delaware & Raritan Canal, Six Mile Run Culvert, .2 mile South of Blackwells Mills Road, East Millstone, Somerset County, NJ

  1. Birefringent corrugated waveguide

    DOEpatents

    Moeller, Charles P. (Del Mar, CA)

    1990-01-01

    A corrugated waveguide having a circular bore and noncircularly symmetric corrugations, and preferably elliptical corrugations, provides birefringence for rotation of polarization in the HE.sub.11 mode. The corrugated waveguide may be fabricated by cutting circular grooves on a lathe in a cylindrical tube or rod of aluminum of a diameter suitable for the bore of the waveguide, and then cutting an approximation to ellipses for the corrugations using a cutting radius R.sub.0 from the bore axis that is greater than the bore radius, and then making two circular cuts using a radius R.sub.1 less than R.sub.0 at centers +b and -b from the axis of the waveguide bore. Alternatively, stock for the mandrel may be formed with an elliptical transverse cross section, and then only the circular grooves need be cut on a lathe, leaving elliptical corrugations between the grooves. In either case, the mandrel is first electroplated and then dissolved leaving a corrugated waveguide with noncircularly symmetric corrugations. A transition waveguide is used that gradually varies from circular to elliptical corrugations to couple a circularly corrugated waveguide to an elliptically corrugated waveguide.

  2. Development of gprs-based leak detection system for pipe pushing crossing part of nature gas pipeline

    Microsoft Academic Search

    Fujun Liu; Shuai Kong; Zhangwei Ling; Mulin Zheng; Yueqiang Qian

    2011-01-01

    There would be a sealed space, called culvert box, between the nature gas pipeline and the concrete pipe when the nature gas pipeline crossing highways, railways and rivers using the trenchless pipe pushing technology. To deal with the problem of leak detection and monitoring for these culvert boxes, which were located in the field and scattered, a GPRS-based (GPRS: general

  3. Corrugated Cardboard Scenery Construction.

    ERIC Educational Resources Information Center

    Wedwick, Daryl M.

    The use of corrugated cardboard in constructing stage scenery is discussed in this paper. In the first section, both the advantages and the problems associated with using the material are discussed, as are ways to avoid problems. The second section of the paper discusses general methods for preparing corrugated materials for set and prop…

  4. 1. View southeast at northwest facade of dewatered culvert outlet ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. View southeast at northwest facade of dewatered culvert outlet headwall, above which part of the canal bank has been removed. Buttresses and upper portion of headwall (above arches) are nineteenth-century additions to the lower, original headwall. - Delaware & Raritan Canal, Ten Mile Run Culvert, 1.5 miles South of Blackwells Road, East Millstone, Somerset County, NJ

  5. Incipient motion of gravel in a bottomless arch culvert

    Microsoft Academic Search

    B. M. CROOKSTON; B. P. M. TULLIS

    2011-01-01

    Incipient motion was investigated for four gravel substrate materials in a bottomless arch culvert and a rectangular flume. Different methods for calculating Shields parameter at incipient motion (?c) based upon local flow parameters were explored. An incipient motion region for bottomless arch culverts in fully turbulent flow was defined with two bounding curves on Shields diagram. The variation of ?c

  6. Earth pressures on reinforced concrete box culverts 

    E-print Network

    Brown, Dale Evan

    1986-01-01

    spec. 0698-78 3 100 80 60 g ~40 20 10. 0 1. 0 Grain Size (mm) 0. 1 FIG. 2 - Grain Size Curve for Fine, Red, Clayey Sand 0. 01 TABLE 3 - In-Situ Dry Unit Weights and Moisture Contents of the Fine, Red, Clayey Sand at the Test Site Dry Unit... and dead load tests were performed on an instrumented 8 x 8 x 44 ft (2. 4 x 2. 4 x 13. 4 m) reinforced concrete box culvert. Earth pressures measurements were obtained and analyzed. A set of empirical equations were developed to model the measured live...

  7. Drainage culverts as habitat linkages and factors affecting passage by mammals

    Microsoft Academic Search

    Anthony P. Clevenger; Bryan Chruszcz; Kari Gunson

    2001-01-01

    Summary 1. Drainage culverts are ubiquitous features in road corridors, yet little is known about the efficacy of culverts for increasing road permeability and habitat connectivity for terrestrial wildlife. Culvert use by small- and medium-sized mammals was investigated along roads in Banff National Park, Alberta, Canada. An array of culvert types was sampled varying in dimensions, habitat and road features

  8. 7. View north at back (canal side) of culvert inlet, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. View north at back (canal side) of culvert inlet, with canal bank completely removed. Background to foreground: back of inlet headwall with tops of high inlet barrels exposed; vertical transition wall between high inlet barrels and low, interior, inlet barrels; tops of low interior barrels; vertical heartening planks and low cutoff wall at site of former canal edge of canal bank; dewatered canal bed and plank sheathing on top of culvert barrels beneath canal bed. - Delaware & Raritan Canal, Ten Mile Run Culvert, 1.5 miles South of Blackwells Road, East Millstone, Somerset County, NJ

  9. Juniata Street Culvert. Havre de Grace, Hareford Co., MD. Sec. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Juniata Street Culvert. Havre de Grace, Hareford Co., MD. Sec. 1201, MP 60.77. - Northeast Railroad Corridor, Amtrak route between District of Columbia/Maryland state line & Maryland/Delaware state line, Baltimore, Independent City, MD

  10. South portal of Culvert No. 1508 in Old Town, Maryland, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    South portal of Culvert No. 1508 in Old Town, Maryland, looking north. - Western Maryland Railway, Cumberland Extension, Pearre to North Branch, from WM milepost 125 to 160, Pearre, Washington County, MD

  11. SEVERN RUN CULVERT. MAYFIELD, ANNE ARUNDEL CO., MD Sec. 1201, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    SEVERN RUN CULVERT. MAYFIELD, ANNE ARUNDEL CO., MD Sec. 1201, MP 112.17. - Northeast Railroad Corridor, Amtrak route between District of Columbia/Maryland state line & Maryland/Delaware state line, Baltimore, Independent City, MD

  12. 11. VIEW OF FLOOD GATE FOR THE PRESSURE CULVERT AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. VIEW OF FLOOD GATE FOR THE PRESSURE CULVERT AND THE SOUTH AND EAST ELEVATIONS, LOOKING NORTHWEST. - Wyoming Valley Flood Control System, Woodward Pumping Station, East of Toby Creek crossing by Erie-Lackawanna Railroad, Edwardsville, Luzerne County, PA

  13. 9. VIEW OF THE PRESSURE CULVERT STILLING BASIN, LOOKING NORTH. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. VIEW OF THE PRESSURE CULVERT STILLING BASIN, LOOKING NORTH. NOTE THE LEVEE TO THE RIGHT. - Wyoming Valley Flood Control System, Woodward Pumping Station, East of Toby Creek crossing by Erie-Lackawanna Railroad, Edwardsville, Luzerne County, PA

  14. 8. Double arch culvert on Laurel Creek Road looking WSW. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Double arch culvert on Laurel Creek Road looking WSW. - Great Smoky Mountains National Park Roads & Bridges, Cades Cove Road & Laurel Creek Road, From Townsend Wye to Cades Cove, Gatlinburg, Sevier County, TN

  15. 9. Double arch culvert on Laurel Creek Road looking ENE. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. Double arch culvert on Laurel Creek Road looking ENE. - Great Smoky Mountains National Park Roads & Bridges, Cades Cove Road & Laurel Creek Road, From Townsend Wye to Cades Cove, Gatlinburg, Sevier County, TN

  16. 6. View southwest, culvert inlet with canal bank completely removed. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. View southwest, culvert inlet with canal bank completely removed. Left to right: back of headwall; tops of high inlet barrels; vertical transition wall between high inlet barrels and low, interior, inlet barrels; tops of low interior barrels; vertical heartening planks and low cutoff wall along former edge of canal bank; dewatered canal bed. - Delaware & Raritan Canal, Ten Mile Run Culvert, 1.5 miles South of Blackwells Road, East Millstone, Somerset County, NJ

  17. 8. View southwest at the northeastern end of culvert inlet, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. View southwest at the northeastern end of culvert inlet, with canal bank completely removed. Left to right: back of curved wingwall; tops of high inlet barrels; vertical transition wall between high inlet barrels and low interior barrels; tops of low, interior barrels; vertical heartening planks at former canal edge of canal bank. - Delaware & Raritan Canal, Ten Mile Run Culvert, 1.5 miles South of Blackwells Road, East Millstone, Somerset County, NJ

  18. Dealing With Uncertainty When Assessing Fish Passage Through Culvert Road Crossings

    NASA Astrophysics Data System (ADS)

    Anderson, Gregory B.; Freeman, Mary C.; Freeman, Byron J.; Straight, Carrie A.; Hagler, Megan M.; Peterson, James T.

    2012-09-01

    Assessing the passage of aquatic organisms through culvert road crossings has become increasingly common in efforts to restore stream habitat. Several federal and state agencies and local stakeholders have adopted assessment approaches based on literature-derived criteria for culvert impassability. However, criteria differ and are typically specific to larger-bodied fishes. In an analysis to prioritize culverts for remediation to benefit imperiled, small-bodied fishes in the Upper Coosa River system in the southeastern United States, we assessed the sensitivity of prioritization to the use of differing but plausible criteria for culvert impassability. Using measurements at 256 road crossings, we assessed culvert impassability using four alternative criteria sets represented in Bayesian belief networks. Two criteria sets scored culverts as either passable or impassable based on alternative thresholds of culvert characteristics (outlet elevation, baseflow water velocity). Two additional criteria sets incorporated uncertainty concerning ability of small-bodied fishes to pass through culverts and estimated a probability of culvert impassability. To prioritize culverts for remediation, we combined estimated culvert impassability with culvert position in the stream network relative to other barriers to compute prospective gain in connected stream habitat for the target fish species. Although four culverts ranked highly for remediation regardless of which criteria were used to assess impassability, other culverts differed widely in priority depending on criteria. Our results emphasize the value of explicitly incorporating uncertainty into criteria underlying remediation decisions. Comparing outcomes among alternative, plausible criteria may also help to identify research most needed to narrow management uncertainty.

  19. Dealing with uncertainty when assessing fish passage through culvert road crossings

    USGS Publications Warehouse

    Anderson, Gregory B.; Freeman, Mary C.; Freeman, Byron J.; Straight, Carrie A.; Hagler, Megan M.; Peterson, James T.

    2012-01-01

    Assessing the passage of aquatic organisms through culvert road crossings has become increasingly common in efforts to restore stream habitat. Several federal and state agencies and local stakeholders have adopted assessment approaches based on literature-derived criteria for culvert impassability. However, criteria differ and are typically specific to larger-bodied fishes. In an analysis to prioritize culverts for remediation to benefit imperiled, small-bodied fishes in the Upper Coosa River system in the southeastern United States, we assessed the sensitivity of prioritization to the use of differing but plausible criteria for culvert impassability. Using measurements at 256 road crossings, we assessed culvert impassability using four alternative criteria sets represented in Bayesian belief networks. Two criteria sets scored culverts as either passable or impassable based on alternative thresholds of culvert characteristics (outlet elevation, baseflow water velocity). Two additional criteria sets incorporated uncertainty concerning ability of small-bodied fishes to pass through culverts and estimated a probability of culvert impassability. To prioritize culverts for remediation, we combined estimated culvert impassability with culvert position in the stream network relative to other barriers to compute prospective gain in connected stream habitat for the target fish species. Although four culverts ranked highly for remediation regardless of which criteria were used to assess impassability, other culverts differed widely in priority depending on criteria. Our results emphasize the value of explicitly incorporating uncertainty into criteria underlying remediation decisions. Comparing outcomes among alternative, plausible criteria may also help to identify research most needed to narrow management uncertainty.

  20. Remaining Sites Verification Package for the 100-F-50 Stormwater Runoff Culvert, Waste Site Reclassification Form 2007-001

    SciTech Connect

    J. M. Capron

    2008-04-15

    The 100-F-50 waste site, part of the 100-FR-2 Operable Unit, is a steel stormwater runoff culvert that runs between two railroad grades in the south-central portion of the 100-F Area. The culvert exiting the west side of the railroad grade is mostly encased in concrete and surrounded by a concrete stormwater collection depression partially filled with soil and vegetation. The drain pipe exiting the east side of the railroad grade embankment is partially filled with soil and rocks. The 100-F-50 stormwater diversion culvert confirmatory sampling results support a reclassification of this site to no action. The current site conditions achieve the remedial action objectives and corresponding remedial action goals established in the Remaining Sites ROD. The results of confirmatory sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River.

  1. Feasibility of culvert IED detection using thermal neutron activation

    NASA Astrophysics Data System (ADS)

    Faust, Anthony A.; McFee, John E.; Clifford, Edward T. H.; Andrews, Hugh Robert; Mosquera, Cristian; Roberts, William C.

    2012-06-01

    Bulk explosives hidden in culverts pose a serious threat to the Canadian and allied armies. Culverts provide an opportunity to conceal insurgent activity, avoid the need for detectable surface disturbances, and limit the applicability of conventional sub-surface sensing techniques. Further, in spite of the large masses of explosives that can be employed, the large sensor{target separation makes detection of the bulk explosive content challeng- ing. Defence R&D Canada { Sueld and Bubble Technology Industries have been developing thermal neutron activation (TNA) sensors for detection of buried bulk explosives for over 15 years. The next generation TNA sensor, known as TNA2, incorporates a number of improvements that allow for increased sensor-to-target dis- tances, making it potentially feasible to detect large improvised explosive devices (IEDs) in culverts using TNA. Experiments to determine the ability of TNA2 to detect improvised explosive devices in culverts are described, and the resulting signal levels observed for relevant quantities of explosives are presented. Observations conrm that bulk explosives detection using TNA against a culvert-IED is possible, with large charges posing a detection challenge at least as dicult as that of a deeply buried anti-tank landmine. Because of the prototype nature of the TNA sensor used, it is not yet possible to make denitive statements about the absolute sensitivity or detection time. Further investigation is warranted.

  2. Response of bull trout (Salvelinus confluentus) to habitat reconnection through replacement of hanging culverts with bridges

    Microsoft Academic Search

    J. Mark Shrimpton; Christopher J. Cena; Adrian D. Clarke

    We examined the effectiveness of road culvert replacement on providing access to fish habitat in two tributary streams of the Torpy River, in central British Columbia. For both study streams, culverts had been \\

  3. An Improved Method of Manufacturing Corrugated Boxes: Lateral Corrugator

    SciTech Connect

    Frank C. Murray Ph.D.; , Roman Popil Ph.D.; Michael Shaepe (formerly with IPST, now at Cargill. Inc)

    2008-12-18

    Paper physicists have known that a corrugated box constructed from outer liner sheets having a predominant fiber orientation aligned with the corrugating flute direction would have higher stiffness and crush resistance (per unit of fiber weight) than the conventional box construction. Such increased performance per unit of fiber weight could result in fiber reduction and energy savings for boxes having equivalent performance specifications. The goal of this project was to develop and demonstrate a commercially viable lateral corrugating process. This included designing and building a pilot lateral corrugator, testing and evaluating pilot machine made boxes, and developing a strategy for commercialization.

  4. Shear Behavior and Mode of Failure for ASTM C1433 Precast Box Culverts

    Microsoft Academic Search

    Ali Abolmaali; Anil Garg

    2009-01-01

    This study evaluates the shear behavior and capacity of the precast concrete box culverts subjected to HS 20 truck wheel load. The most critical culvert behavior was considered by studying culverts subjected to zero depth of the fill and placed on a rigid bedding material. Full-scale experimental tests, with wheel load placed at the distance d from the tip of

  5. 7. VIEW OF WEAPONS DELIVERY ROAD CULVERT OF LOWER DIAGONAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. VIEW OF WEAPONS DELIVERY ROAD CULVERT OF LOWER DIAGONAL NO. 1 DRAIN, LOOKING 522 EAST OF NORTH. - Truckee-Carson Irrigation District, Lower Diagonal No. 1 Drain, Bounded by West Gate Road & Weapons Delivery Road, Naval Air Station Fallon, Fallon, Churchill County, NV

  6. Turtles and culverts, and alternative energy development: an unreported but potentially significant mortality threat to the desert tortoise (Gopherus agassizii)

    USGS Publications Warehouse

    Lovich, J.E.; Ennen, J.R.; Madrak, S.; Grover, B.

    2011-01-01

    Culverts are often used to increase the permeability of roaded landscapes for wildlife, including turtles. Although the benefits of culverts as safe passages for turtles are well documented, under some conditions culverts can entrap them and cause mortality. Here we report a culvert-related mortality in the federally threatened desert tortoise (Gopherus agassizii) at a wind energy facility in California and offer simple recommendations to mitigate the negative effects of culverts for wildlife in general.

  7. Culvert analysis program for indirect measurement of discharge

    USGS Publications Warehouse

    Fulford, Janice M.

    1993-01-01

    A program based on the U.S. Geological Survey (USGS) methods for indirectly computing peak discharges through culverts allows users to employ input data formats used by the water surface profile program (WSPRO). The program can be used to compute discharge rating surfaces or curves that describe the behavior of flow through a particular culvert or to compute discharges from measurements of upstream of the gradually varied flow equations and has been adapted slightly to provide solutions that minimize the need for the user to determine between different flow regimes. The program source is written in Fortran 77 and has been run on mini-computers and personal computers. The program does not use or require graphics capability, a color monitor, or a mouse.

  8. 24. CULVERT WITH CONCRETE HEADWALL AND SIDEWALLS CARRYING THE LATERAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    24. CULVERT WITH CONCRETE HEADWALL AND SIDEWALLS CARRYING THE LATERAL UNDER 8TH AVENUE. - Highline Canal, Sand Creek Lateral, Beginning at intersection of Peoria Street & Highline Canal in Arapahoe County (City of Aurora), Sand Creek lateral Extends 15 miles Northerly through Araphoe County, City & County of Denver, & Adams County to its end point, approximately 1/4 mile Southest of intersectioin of D Street & Ninth Avenue in Adams County (Rocky Mountain Arsenal, Commerce City Vicinity), Commerce City, Adams County, CO

  9. Effect of Wheel Live Load on Shear Behavior of Precast Reinforced Concrete Box Culverts

    Microsoft Academic Search

    Ali Abolmaali; Anil K. Garg

    2008-01-01

    This study reports on a part of a comprehensive study to evaluate the shear capacity of the precast reinforced concrete box culverts. Six full-scale 2.4 m 8f t span box culverts were tested to failure by subjecting each culvert to the AASHTO HS-20 wheel load. The location of the wheel load was varied from the tip of the haunch as

  10. 49 CFR 1242.15 - Roadway, tunnels and subways, bridges and culverts, ties, rails, other track material, ballast...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Transportation 9 2011-10-01 2011-10-01 false Roadway, tunnels and subways, bridges and culverts, ties, rails, other...Operating Expenses-Way and Structures § 1242.15 Roadway, tunnels and subways, bridges and culverts, ties, rails,...

  11. 49 CFR 1242.15 - Roadway, tunnels and subways, bridges and culverts, ties, rails, other track material, ballast...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Transportation 9 2013-10-01 2013-10-01 false Roadway, tunnels and subways, bridges and culverts, ties, rails, other...Operating Expenses-Way and Structures § 1242.15 Roadway, tunnels and subways, bridges and culverts, ties, rails,...

  12. 49 CFR 1242.15 - Roadway, tunnels and subways, bridges and culverts, ties, rails, other track material, ballast...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Transportation 9 2012-10-01 2012-10-01 false Roadway, tunnels and subways, bridges and culverts, ties, rails, other...Operating Expenses-Way and Structures § 1242.15 Roadway, tunnels and subways, bridges and culverts, ties, rails,...

  13. 49 CFR 1242.15 - Roadway, tunnels and subways, bridges and culverts, ties, rails, other track material, ballast...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Transportation 9 2014-10-01 2014-10-01 false Roadway, tunnels and subways, bridges and culverts, ties, rails, other...Operating Expenses-Way and Structures § 1242.15 Roadway, tunnels and subways, bridges and culverts, ties, rails,...

  14. 49 CFR 1242.15 - Roadway, tunnels and subways, bridges and culverts, ties, rails, other track material, ballast...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Transportation 9 2010-10-01 2010-10-01 false Roadway, tunnels and subways, bridges and culverts, ties, rails, other...Operating Expenses-Way and Structures § 1242.15 Roadway, tunnels and subways, bridges and culverts, ties, rails,...

  15. Landscape-level stream fragmentation caused by hanging culverts along roads in Alberta’s boreal forest

    Microsoft Academic Search

    David Park; Michael Sullivan; Erin Bayne; Garry Scrimgeour

    2008-01-01

    Hanging culverts (i.e., outfall elevated above the stream surface) can fragment fish communities in streams by creating upstream movement barriers. We conducted a retrospective study of culvert stream crossings along industrial roads in Alberta's boreal forest to describe factors relating to the occurrence of hanging culverts and to quantify watershed fragmentation. One-half (50%; 187\\/374) of culverts surveyed in four watersheds

  16. Finite-Element Modeling and Analysis of Reinforced Concrete Box Culverts

    Microsoft Academic Search

    Anil K. Garg; Ali Abolmaali

    2009-01-01

    There have been several controversies with regard to the true behavior of reinforced concrete box culverts in recent years. To be able to conduct a parametric study to develop design equations, a complete three-dimensional verified finite-element model of culverts is essential. This study presents the development of an analytical program to investigate the shear capacity of precast reinforced concrete box

  17. C&O Canal Fifteen Mile Creek Culvert in foreground, south portal ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    C&O Canal Fifteen Mile Creek Culvert in foreground, south portal of Western Maryland's Fifteen Mile Creek Culvert in rear, looking west. - Western Maryland Railway, Cumberland Extension, Pearre to North Branch, from WM milepost 125 to 160, Pearre, Washington County, MD

  18. Assessment of Trout Passage through Culverts in a Large Montana Drainage during Summer Low Flow

    Microsoft Academic Search

    D. Drake Burford; Thomas E. McMahon; Joel E. Cahoon; Matthew Blank

    2009-01-01

    We used a combination of methods to assess the degree of fish passage restriction from road culverts during summer low flow for westslope cutthroat trout Oncorhynchus clarkii lewisi and brook trout Salvelinus fontinalis across a large drainage basin. The FishXing fish passage model classified 41 of 45 (91%) culverts as barriers to upstream passage for 152-mm westslope cutthroat trout. Population

  19. MONITORING CULVERT PASSAGE OF JUVENILE SALMONIDS WITH PIT TAGS AND STATIONARY AND PORTABLE PIT-TAG READERS

    EPA Science Inventory

    Federal land management agencies in the PNW face increasing pressure to replace culverts that do not pass all life history stages of anadromous salmon and trout. Prioritization of culverts for replacement is often based on the physical parameters of culverts, and not on how fish...

  20. Corrugated panels under dynamic loads

    Microsoft Academic Search

    Y. H. Liang; L. A. Louca; R. E. Hobbs

    2007-01-01

    Corrugated panels are commonly used as blast walls on offshore installations, and an assessment of their response to dynamic pressure loads needs to be made during design. Although detailed numerical models are commonly used, simplified models based on spring-mass idealisations, such as Biggs’ method, are still important for preliminary design. Based on an earlier static formulation, the dynamic response of

  1. A Simple Experiment to Explore Standing Waves in a Flexible Corrugated Sound Tube

    NASA Astrophysics Data System (ADS)

    Amorim, Maria Eva; Sousa, Teresa Delmira; Carvalho, P. Simeão; Sousa, Adriano Sampaioe

    2011-09-01

    Sound tubes, pipes, and singing rods are used as musical instruments and as toys to perform amusing experiments. In particular, corrugated tubes present unique characteristics with respect to the sounds they can produce; that is why they have been studied so intensively, both at theoretical and experimental levels.1-4 Experimental studies usually involve expensive and sophisticated equipment that is out of reach of school laboratory facilities.3-6 In this paper we show how to investigate quantitatively the sounds produced by a flexible sound tube corrugated on the inside by using educational equipment readily available in school laboratories, such as the oscilloscope, the microphone, the anemometer, and the air pump. We show that it is possible for students to study the discontinuous spectrum of sounds produced by a flexible corrugated tube and go even further, computing the speed of sound in air with a simple experimental procedure.

  2. Experimental Investigation of Shear Capacity of Precast Reinforced Concrete Box Culverts

    Microsoft Academic Search

    Anil K. Garg; Ali Abolmaali; Raul Fernandez

    2007-01-01

    This study presents an experimental program to investigate the shear capacity of precast reinforced concrete box culverts. Each culvert was subjected to monotonically increasing load through a 254 mm508 mm 10 in.20 in. load plate in order to simulate the HS20 truckload per AASHTO 2005. Instrumentation included strain gauges, high-resolution laser deflection sensor, and automated data acquisition. Four tests were

  3. Badger Roadkill Risk in Relation to the Presence of Culverts and Jersey Barriers

    Microsoft Academic Search

    Trevor A. Kinley; Nancy J. Newhouse

    2009-01-01

    Abstract The subspecies of American badger,found in British Columbia,(Taxidea taxus jeffersonii) is provincially red-listed and nationally endangered.,The primary cause,of mortality is roadkill. Eur opean,badgers,(Melesmeles ) and other carnivores,are known to pass under highways using culverts, and there are indications that American badgers do also, suggesting,that the presence,of more culverts might be associated with lower roadkill risk for American badgers. Furthermore,

  4. Corrugated Limiting Tab for Jet Mixing

    NASA Astrophysics Data System (ADS)

    Kaushik, Mrinal; Rathakrishnan, E.

    2013-12-01

    The mixing promoting efficiency of a limiting corrugated tab, located across a diameter of Mach 1.73 convergent-divergent circular nozzle exit, has been studied experimentally. With uncorrugated tab the core length reduction achieved is just 42%, but for the tab with semi-circular corrugations, the reduction in core length is as high as 98%, at underexpanded level corresponding to NPR 6. The corrugation geometries have a strong effect on the mixing promoting capability of the tab. The mixing promotion is found to be the best when there is no pressure gradient at the nozzle exit. Among the corrugated tabs studied, the tab with semi-circular corrugations is found to be the best mixing promoter. The core length reduction achieved for the correctly expanded jet with the tab with semi-circular corrugations is almost 98%, whereas the reduction caused by the tabs with triangular and rectangular corrugations are 96% and 92%, respectively. In addition to reducing the core length the corrugated tabs were found to be weakening the waves and shortening the shock cells length.

  5. Estimates for Pu-239 loadings in burial ground culverts based on fast/slow neutron measurements

    SciTech Connect

    Winn, W.G.; Hochel, R.C.; Hofstetter, K.J.; Sigg, R.A.

    1989-08-15

    This report provides guideline estimates for Pu-239 mass loadings in selected burial ground culverts. The relatively high recorded Pu-239 contents of these culverts have been appraised as suspect relative to criticality concerns, because they were assayed only with the solid waste monitor (SWM) per gamma-ray counting. After 1985, subsequent waste was also assayed with the neutron coincidence counter (NCC), and a comparison of the assay methods showed that the NCC generally yielded higher assays than the SWM. These higher NCC readings signaled a need to conduct non-destructive/non-intrusive nuclear interrogations of these culverts, and a technical team conducted scoping measurements to illustrate potential assay methods based on neutron and/or gamma counting. A fast/slow neutron method has been developed to estimate the Pu-239 in the culverts. In addition, loading records include the SWM assays of all Pu-239 cuts of some of the culvert drums and these data are useful in estimating the corresponding NCC drum assays from NCC vs SWM data. Together, these methods yield predictions based on direct measurements and statistical inference.

  6. Method and apparatus for corrugating strips

    DOEpatents

    Day, J.R.; Curtis, C.H.

    1981-10-27

    The invention relates to a method and a machine for transversely corrugating a continuous strip of metallic foil. The product foil comprises a succession of alternately disposed corrugations, each defining in a cross section, a major segment of a circle. The foil to be corrugated is positioned to extend within a vertical passage in the machine. The walls of the passage are heated to promote the desired deformation of the foil. Foil-deforming rollers are alternately passed obliquely across the passage to respectively engage transverse sections of the foil. The rollers and their respective section of deformed foil comprise a stacked assembly which is moved incrementally through the heated passageway. As the assembly emerges from the passageway, the rollers spill from the corrugated foil and are recovered for re-use.

  7. Practical piping handbook

    Microsoft Academic Search

    Mendel

    1981-01-01

    A reference book on pipes, pipe fitting, and pipe treatment in the petroleum and natural gas industries is presented. The contents include: standard piping terminology; piping codes and standards; pipe manufacturing sizes; metallic piping; non-metallic piping; lined and coated piping systems; pipe tracing and jacketing; fittings and flanges; piping connections; valves; pipe expansion devices; flexible piping; piping specialties; pipe supports

  8. Sensitivity to disparity corrugations in peripheral vision

    Microsoft Academic Search

    Sj Prince; Bj Rogers

    1998-01-01

    Abstract Disparity discrimination,thresholds,are known,to increase with,both,retinal eccentricity and distance from the horopter. However, little is known about how the detectability of cyclopean gratings varies with retinal position. Thresholds for disparity corrugations were measured as a function,of corrugation,frequency,for different visual eccentricities. Subjects viewed,annular displays of random dot stereograms, and judged in which of two intervals a circumferential disparity modulation was present.

  9. CORRECTING UNRELIABLE VELOCITY DISTRIBUTIONS IN SHORT CULVERTS AND CANAL REACHES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irrigation water management increasingly depends on good water flow measurement. Too frequently, flow disturbances from upstream elbows, the well pump, or other pipe fittings, produce distorted flow profiles that are detrimental to the proper installation and operation of common flow meters used in...

  10. Effects of Culverts on Stream Fish Assemblages in the Alberta Foothills

    Microsoft Academic Search

    Laura M. MacPherson; Michael G. Sullivan; A. Lee Foote; Cameron E. Stevens

    2012-01-01

    Watercourse-crossing structures are ubiquitous anthropogenic features in the Rocky Mountain foothills of Alberta. We performed physical and habitat assessments at 295 watercourse-crossing sites in 15 subbasins of the Athabasca River during the summer and early fall of 2007, 2008, and 2009, sampling for fish at 110 sites (32 bridges and 78 culverts). We used bootstrapping analysis to examine how several

  11. Effect of Culverts on Predator-Prey Interactions in a Tropical Stream

    Microsoft Academic Search

    C. L. Hein; D. A. Kikkert; T. A. Crowl

    2005-01-01

    As part of a biocomplexity project in Puerto Rico, we use river and road networks as a platform to understand the interactions between stream biota, the physical environment, and human activity. Specifically, we ask if humans affect aquatic organisms through road building and recreational activities. Culverts have been documented to impede or slow migration of aquatic biota. This is especially

  12. Culvert Design for Flood Routing considering Sediment Transport W.J. Rahmeyer PhD.1

    E-print Network

    Rahmeyer, William J.

    . The transport of bed-load is subject to the same incipient motion criteria as open channel flow, and can form-load through a 30.20 cm diameter culvert. The tests were successful in demonstrating and determining incipient motion criteria, bed form regimes, energy loss, and transport rates under a variety of flow rates

  13. Imaging Buried Culverts Using Ground Penetrating Radar: Comparing 100 MHZ Through 1 GHZ Antennae

    NASA Astrophysics Data System (ADS)

    Abdul Aziz, A.; Stewart, R. R.; Green, S. L.

    2013-12-01

    *Aziz, A A aabdulaziz@uh.edu Allied Geophysical Lab, Department of Earth and Atmospheric Sciences, University of Houston, TX, USA Stewart, R R rrstewart@uh.edu Allied Geophysical Lab, Department of Earth and Atmospheric Sciences, University of Houston, TX, USA *Green, S L slgreen@yahoo.com Allied Geophysical Lab, Department of Earth and Atmospheric Sciences, University of Houston, TX, USA A 3D ground penetrating radar (GPR) survey, using three different frequency antennae, was undertaken to image buried steel culverts at the University of Houston's La Marque Geophysical Observatory 30 miles south of Houston, Texas. The four culverts, under study, support a road crossing one of the area's bayous. A 32 m by 4.5 m survey grid was designed on the road above the culverts and data were collected with 100 MHz, 250 MHz, and 1 GHz antennae. We used an orthogonal acquisition geometry for the three surveys. Inline sampling was from 1.0 cm to 10 cm (from 1 GHz to 100 MHz antenna) with inline and crossline spacings ranging from 0.2 m to 0.5 m. We used an initial velocity of 0.1 m/ns (from previous CMP work at the site) for the display purposes. The main objective of the study was to analyze the effect of different frequency antennae on the resultant GPR images. We are also interested in the accuracy and resolution of the various images, in addition to developing an optimal processing flow.The data were initially processed with standard steps that included gain enhancement, dewow and temporal-filtering, background suppression, and 2D migration. Various radar velocities were used in the 2D migration and ultimately 0.12 m/ns was used. The data are complicated by multipathing from the surface and between culverts (from modeling). Some of this is ameliorated via deconvolution. The top of each of the four culverts was evident in the GPR images acquired with the 250 MHz and 100 MHz antennas. For 1 GHz, the top of the culvert was not clear due to the signal's attenuation. The 250 MHz shielded antenna provides a vertical resolution of about 0.1 m and is the choice to image the culverts. The 100 MHz antenna provided an increment in depth of penetration, but at the expense of a substantially diminished resolution (0.25 m).

  14. High frequency scattering from corrugated stratified cylinders

    NASA Technical Reports Server (NTRS)

    Sarabandi, Kamal; Ulaby, Fawwaz T.

    1991-01-01

    Interest in applying radar remote sensing for the study of forested areas led to the development of a model for scattering from corrugated stratified dielectric cylinders. The model is used to investigate the effect of bark and its roughness on scattering from tree trunks and branches. The outer layer of the cylinder (bark) is assumed to be a low-loss dielectric material and to have a regular (periodic) corrugation pattern. The inner layers are treated as lossy dielectrics with smooth boundaries. A hybrid solution based on the moment method and the physical optics approximation is obtained. In the solution, the corrugations are replaced with polarization currents that are identical to those of the local tangential periodic corrugated surface, and the stratified cylinder is replaced with equivalent surface currents. New expressions for the equivalent physical-optics currents are used which are more convenient than the standard ones. It is shown that the bark layer and its roughness both reduce the radar cross-section. It is also demonstrated that the corrugations can be replaced by an equivalent anisotropic layer.

  15. An Analysis of Stream Culvert Fish Passage on the Navy Railroad Line between Bremerton and Shelton, Washington

    SciTech Connect

    May, Christopher W.; Miller, Martin C.; Southard, John A.

    2004-10-25

    The Navy railroad service line runs between Shelton, Bremerton, and Silverdale, and is used by the Navy to transfer freight to its facilities. It is also used by commercial clients to ship service items and bulk cargo for municipalities along portions of the route. Culverts of various size and construction convey streams and stormwater runoff under the railroad line. These allow transfer of water and, in some cases allow for passage of juvenile and adult salmon into waters upstream of the culverts. As part of this project, 21 culverts along a 34-mile reach (Shelton to Bremerton) of this railroad were surveyed to evaluate their function and ability to allow salmon to utilize the streams. The culverts and attached watersheds were evaluated using criteria developed by the Washington Department of Fish and Wildlife to assign a Priority Index (PI) to barriers present on each fish-bearing stream. The PI is a relative numeric rating indicator, assigned using consistent criteria related to the degree of potential habitat gained by removing barriers and improving the function of the watershed. Of the 21 culverts evaluated, five were found to be complete fish-passage barriers and six were found to be partial barriers, primarily to juvenile salmon. Three of these culverts had PI ratings above 10 and five others had ratings between 7 and 10. Corrective action can be taken based on any PI rating, but the WDFW normally assigns lower priority to projects with PI scores lower than 15. Several of the stream and culverts had previously been evaluated for structural integrity and function and have been scheduled for repair. A narrative indicating the condition of the culvert has been prepared as well as a table indicating the PI scores and a summary of recommendations for action for each culvert.

  16. Composite corrugated structures for morphing wing skin applications

    Microsoft Academic Search

    C. Thill; J. A. Etches; I. P. Bond; K. D. Potter; P. M. Weaver

    2010-01-01

    Composite corrugated structures are known for their anisotropic properties. They exhibit relatively high stiffness parallel (longitudinal) to the corrugation direction and are relatively compliant in the direction perpendicular (transverse) to the corrugation. Thus, they offer a potential solution for morphing skin panels (MSPs) in the trailing edge region of a wing as a morphing control surface. In this paper, an

  17. Generation of periodic surface corrugations.

    PubMed

    Johnson, L F; Kammlott, G W; Ingersoll, K A

    1978-04-15

    The generation of periodic surface corrugations by ion-beam milling and chemical etching of grating relief patterns in photoresist is analyzed. A general treatment is developed for gratings of any desired period on substrates of arbitrary reflectivity, but particular emphasis is given to the generation of gratings with deep grooves and fine periods (Lambda < 3000 A) on GaAs. Analysis of the intensity distribution in photoresist for both p- and s-polarized incident beams reveals that the standing waves generated by reflection from the substrate are diminished for p-polarized beams, but the existence of a displaced grating for certain ranges of substrate reflectivity and angle of incidence severely limits groove depth in resist. The requirements are given for the establishment of an intensity maximum at the photoresist-substrate interface, a condition desired for subsequent chemical etching. It is shown further that the alternative use of a quarterwave intermediate oxide layer to achieve this condition on GaAs results in a lower limit being imposed on grating period. Constantintensity contours approximating the groove profiles in resist demonstrate that an imbalance in incident beam intensity may lead to severing of the resist stripes, and the dependence of this phenomenon on substrate reflectivity is determined. For beams of equal intensity, a similar phenomenon occurs with increasing reflectivity of the substrate. The transfer of a grating relief pattern to the substrate by ion-beam milling is treated by considering the erosion profiles produced by ion bombardment. This analysis is used to examine the influence of milling geometry on the depth and shape of the groove. Although the ion-beam milling rate of GaAs is several times greater than AZ-1350 photoresist, it is shown that the groove aspect ratio (depth/period) in GaAs can be no more than about 1.2, a figure that is obtained, surprisingly, by milling at the angle of maximum removal rate of photoresist. For a metal substrate, the groove aspect ratio decreases with increasing grating period. For gratings produced by chemical etch, the problem of the weakly exposed layer of resist adjacent to the substrate is solved by using a combination of ion-beam milling and chemical etching. Using a preferential chemical etch with a sufficiently slow etch rate, gratings with well-defined planar features, a period ~2500 A, and a groove aspect ratio >0.6 have been produced on GaAs. PMID:20197956

  18. Electron scattering on microscopic corrugations in graphene

    Microsoft Academic Search

    M. I. Katsnelson; A. K. Geim

    2008-01-01

    We discuss various scattering mechanisms for Dirac fermions in single-layer graphene. It is shown that scattering on a short-range potential (due to, for example, neutral impurities) is mostly irrelevant for electronic quality of graphene, which is likely to be controlled by charged impurities and ripples (microscopic corrugations of a graphene sheet). The latter are an inherent feature of graphene due

  19. Surface anchoring of rodlike molecules on corrugated substrates

    NASA Astrophysics Data System (ADS)

    Kiyohara, Kenji; Asaka, Kinji; Monobe, Hirosato; Terasawa, Naohiro; Shimizu, Yo

    2006-01-01

    We studied the mechanism of surface anchoring of rodlike molecules on substrates with the surfaces corrugated at molecular scale by molecular-dynamics simulation. We constructed a model for substrates that can have anisotoropic topographical patterns such as corrugation. The structural and thermodynamic properties of rodlike molecules on the corrugated surfaces, including the elastic and anchoring properties, were calculated and the influence of the surface structure on the anchoring was discussed. We found that the rodlike molecules are aligned along the grooves of the corrugated surfaces guided by the anisotropic molecular interaction between the molecules and the corrugated surface. The strength of anchoring was found to be increased when the period of corrugation is decreased at molecular level.

  20. Axial Crushing Characteristics of Circular Tubes with Radial Corrugation

    NASA Astrophysics Data System (ADS)

    Chen, Dai-Heng; Hattori, Kazuyuki; Ozaki, Shingo

    In this paper, the effect of radial corrugation on the crushing behaviors of circular tubes is studied by using the finite element method. The numerical analysis is carried out on two geometrically different types of corrugations, ”radial corrugated tube” (RCT) and ”radial corrugated tube with corners” (RCTC). To compare crushing behaviors of those of corrugated circular tubes, a non-corrugated circular tube (CT) is also analyzed. It is revealed that, in the crushing process, the crushing mode of RCT becomes more unstable than that of CT since the wavelength of the fold becomes long and the fold concentrates to the center of the wavelength. However, when the length and the diameter of the tubes are set to the same levels, RCT demonstrates good energy absorption characteristics. Further, it is shown that the compressive load and load efficiency of RCTC increases due to the corner part.

  1. Deformation characteristics of corrugated composites for morphing wings

    Microsoft Academic Search

    Ruijun Ge; Bangfeng Wang; Changwei Mou; Yong Zhou

    2010-01-01

    To meet the needs of morphing and withstand aerodynamic loads of a morphing wing skin, a corrugated glass fabric-epoxy laminated\\u000a composite is prepared and investigated in this paper. This composite is flexible in the corrugated direction and stiff in\\u000a the transverse direction to the corrugation. FEM models are established and solved to predict the characteristics of the composites\\u000a by the

  2. Heat Pipes

    ERIC Educational Resources Information Center

    Lewis, J.

    1975-01-01

    Describes the construction, function, and applications of heat pipes. Suggests using the heat pipe to teach principles related to heat transfer and gives sources for obtaining instructional kits for this purpose. (GS)

  3. Corrugated skin in a foam core sandwich panel

    Microsoft Academic Search

    Jack Reany; Joachim L. Grenestedt

    2009-01-01

    Sandwich plates with one corrugated and one flat skin were studied with the goal to find configurations with higher strength and\\/or stiffness and reduced weight. A procedure for calculating homogenized orthotropic plate stiffnesses of the sandwich was developed and applied to a number of different profiles. The corrugations lead to increased bending stiffness in one direction but reduced in another.

  4. Disappointment and regret enhance corrugator reactivity in a gambling task

    PubMed Central

    Wu, Yin; Clark, Luke

    2015-01-01

    This study investigated how the corrugator and zygomaticus respond to decision outcomes (i.e., gains and losses). We used a gambling task in which participants were presented with obtained followed by non-obtained outcomes. Activity at the corrugator site was sensitive to decision outcomes, such that higher obtained losses (disappointment) and higher non-obtained gains (regret) both heightened corrugator reactivity. Activity at the zygomaticus site was not responsive to obtained or non-obtained outcomes, but did show sensitivity to emotional images in the same participants, in the form of a positive linear relationship with self-reported emotional valence. Corrugator activity was negatively related to emotional valence. The findings indicate the sensitivity of corrugator to objective decision outcomes and also counterfactual comparisons, highlighting the utility of facial electromyography in research on decision making and gambling behavior. PMID:25345723

  5. Disappointment and regret enhance corrugator reactivity in a gambling task.

    PubMed

    Wu, Yin; Clark, Luke

    2015-04-01

    This study investigated how the corrugator and zygomaticus respond to decision outcomes (i.e., gains and losses). We used a gambling task in which participants were presented with obtained followed by non-obtained outcomes. Activity at the corrugator site was sensitive to decision outcomes, such that higher obtained losses (disappointment) and higher non-obtained gains (regret) both heightened corrugator reactivity. Activity at the zygomaticus site was not responsive to obtained or non-obtained outcomes, but did show sensitivity to emotional images in the same participants, in the form of a positive linear relationship with self-reported emotional valence. Corrugator activity was negatively related to emotional valence. The findings indicate the sensitivity of corrugator to objective decision outcomes and also counterfactual comparisons, highlighting the utility of facial electromyography in research on decision making and gambling behavior. PMID:25345723

  6. Biased Brownian motion in extremely corrugated tubes.

    PubMed

    Martens, S; Schmid, G; Schimansky-Geier, L; Hänggi, P

    2011-12-01

    Biased Brownian motion of point-size particles in a three-dimensional tube with varying cross-section is investigated. In the fashion of our recent work, Martens et al. [Phys. Rev. E 83, 051135 (2011)] we employ an asymptotic analysis to the stationary probability density in a geometric parameter of the tube geometry. We demonstrate that the leading order term is equivalent to the Fick-Jacobs approximation. Expression for the higher order corrections to the probability density is derived. Using this expansion orders, we obtain that in the diffusion dominated regime the average particle current equals the zeroth order Fick-Jacobs result corrected by a factor including the corrugation of the tube geometry. In particular, we demonstrate that this estimate is more accurate for extremely corrugated geometries compared with the common applied method using a spatially-dependent diffusion coefficient D(x, f) which substitutes the constant diffusion coefficient in the common Fick-Jacobs equation. The analytic findings are corroborated with the finite element calculation of a sinusoidal-shaped tube. PMID:22225392

  7. An Evaluation of the Use of Critical Swimming Speed for Determination of Culvert Water Velocity Criteria for Smallmouth Bass

    Microsoft Academic Search

    Stephan Peake

    2004-01-01

    Critical swimming speed (Ucrit) is a common measure of the relationship between exercise intensity and duration within the prolonged performance envelope. This relationship is often used to establish water velocity criteria for fishways and culverts; however, the technique involves the assumptions that fish will choose to move at (1) a swimming speed equivalent to Ucrit and (2) a ground speed

  8. Composite corrugated structures for morphing wing skin applications

    NASA Astrophysics Data System (ADS)

    Thill, C.; Etches, J. A.; Bond, I. P.; Potter, K. D.; Weaver, P. M.

    2010-12-01

    Composite corrugated structures are known for their anisotropic properties. They exhibit relatively high stiffness parallel (longitudinal) to the corrugation direction and are relatively compliant in the direction perpendicular (transverse) to the corrugation. Thus, they offer a potential solution for morphing skin panels (MSPs) in the trailing edge region of a wing as a morphing control surface. In this paper, an overview of the work carried out by the present authors over the last few years on corrugated structures for morphing skin applications is first given. The second part of the paper presents recent work on the application of corrugated sandwich structures. Panels made from multiple unit cells of corrugated sandwich structures are used as MSPs in the trailing edge region of a scaled morphing aerofoil section. The aerofoil section features an internal actuation mechanism that allows chordwise length and camber change of the trailing edge region (aft 35% chord). Wind tunnel testing was carried out to demonstrate the MSP concept but also to explore its limitations. Suggestions for improvements arising from this study were deduced, one of which includes an investigation of a segmented skin. The overall results of this study show that the MSP concept exploiting corrugated sandwich structures offers a potential solution for local morphing wing skins for low speed and small air vehicles.

  9. Demonstration of Angle Dependent Casimir Force Between Corrugations

    E-print Network

    A. A. Banishev; J. Wagner; T. Emig; R. Zandi; U. Mohideen

    2013-05-03

    The normal Casimir force between a sinusoidally corrugated gold coated plate and a sphere was measured at various angles between the corrugations using an atomic force microscope. A strong dependence on the orientation angle of the corrugation is found. The measured forces were found to deviate from the proximity force approximation and are in agreement with the theory based on the gradient expansion including correlation effects of geometry and material properties. We analyze the role of temperature. The obtained results open new opportunities for control of the Casimir effect in micromechanical systems.

  10. Demonstration of angle-dependent Casimir force between corrugations.

    PubMed

    Banishev, A A; Wagner, J; Emig, T; Zandi, R; Mohideen, U

    2013-06-21

    The normal Casimir force between a sinusoidally corrugated gold coated plate and a sphere was measured at various angles between the corrugations using an atomic force microscope. A strong dependence on the orientation angle of the corrugation is found. The measured forces were found to deviate from the proximity force approximation and are in agreement with the theory based on the gradient expansion including correlation effects of geometry and material properties. We analyze the role of temperature. The obtained results open new opportunities for control of the Casimir effect in micromechanical systems. PMID:23829717

  11. Diverse corrugation pattern in radially shrinking carbon nanotubes

    SciTech Connect

    Shima, Hiroyuki; Sato, Motohiro; Iiboshi, Kohtaroh; Ghosh, Susanta; Arroyo, Marino [Division of Applied Physics, Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628, Japan and Department of Applied Mathematics 3, LaCaN, Universitat Politecnica de Catalunya, Barcelona 08034 (Spain); Division of Socio-Environmental Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628 (Japan); Division of Socio-Environmental Engineering, Graduate School of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628 (Japan); Department of Applied Mathematics 3, LaCaN, Universitat Politecnica de Catalunya, Barcelona 08034 (Spain)

    2010-08-15

    Stable cross sections of multiwalled carbon nanotubes subjected to electron-beam irradiation are investigated in the realm of the continuum mechanics approximation. The self-healing nature of sp{sup 2} graphitic sheets implies that selective irradiation of the outermost walls causes their radial shrinkage with the remaining inner walls undamaged. The shrinking walls exert high pressure on the interior part of nanotubes, yielding a wide variety of radial-corrugation patterns (i.e., circumferentially wrinkling structures) in the cross section. All corrugation patterns can be classified into two deformation phases for which the corrugation amplitudes of the innermost wall differ significantly.

  12. Effective Thermal Conductivity of Corrugated Insulating Materials

    NASA Astrophysics Data System (ADS)

    Yamada, Etsuro; Kato, Masayasu; Tomikawa, Takayuki; Takahashi, Kaneko

    The effective thermal conductivity of corrugated insulating materials which are made by polypropylene or polycarbonate have been measured by employing steady state comparison method for several specimen having various thickness and specific weight. The thermal conductivity of them evaluated are also by using the thermal resistance models, and are compared with above measured values and raw materials' conductivity. The main results obtained in this paper are as follows: (1) In regard to the specimen in this paper, the effective thermal conductivity increases with increasing temperature, but the increasing rate of them is small. (2) There are considerable differences between the measured values and the predicted ones that are estimated by using the thermal resistance model in which heat flow by conduction only. This differences increase with increasing specimens' thickness. This difference become extinct by considering the coexistence heat flow of conduction and radiation in the air phase of specimen. (3) The thermal resistance of specimen increases linearly with increasing specimens' thickness.

  13. Heat-transfer performance of corrugated-tube thermosiphons. Part 2; Condenser performance

    SciTech Connect

    Hirashima, M.; Nishikawa, Y.; Taguchi, M. (Takuma Research and Development Co., Ltd. (JP)); Negishi, K. (Tokyo Metropolitan Inst. of Technology (JP)); Kaneko, K. (Univ. of Osaka Prefecture (JP)); Matsuoka, T. (Nissan Motor Co., Ltd. (JP))

    1991-01-01

    A two-phase closed thermosiphon made of a corrugated tube was developed to extend the application field of heat pipes. In the first paper, the thermal performance of the evaporator section was examined with the thermosiphons set vertical or tilted. The paper describes the thermal performance of the condenser section. A condensation heat-transfer coefficient is proposed as a function of Nusselt's theory modified by three parameters: the Lockhart--Martinelli parameter to consider the effect of vapor flow on the condensing surface, and two new parameters concerned with the effects of the inclination angle of the thermosiphon and the fill charge ratio of the working fluid. The former parameter has a linear relation with the condensation heat-transfer coefficient, and the latter two have a quadratic relation.

  14. WEST END OF BUILDING, SHOWING CORRUGATED SIDING OVER REBUILT WEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    WEST END OF BUILDING, SHOWING CORRUGATED SIDING OVER REBUILT WEST WALL, AND SOUTH WALL THAT FORMERLY ADJOINED A POWER HOUSE, CAMERA FACING NORTHEAST. - New Haven Rail Yard, Machine Shop, Vicinity of Union Avenue, New Haven, New Haven County, CT

  15. 4. VIEW OF CORRUGATED STEEL COVER OVER OUTLET GATE VALVE, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. VIEW OF CORRUGATED STEEL COVER OVER OUTLET GATE VALVE, LOOKING NORTH - High Mountain Dams in Upalco Unit, East Timothy Lake Dam, Ashley National Forest, 8.4 miles North of Swift Creek Campground, Mountain Home, Duchesne County, UT

  16. Piping Analysis

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Burns & McDonnell provide architectural and engineering services in planning, design and construction of a wide range of projects all over the world. In design analysis, company regularly uses COSMIC computer programs. In computer testing piping design of a power plant, company uses Pipe Flexibility Analysis Program (MEL-21) to analyze stresses due to weight, temperature, and pressure found in proposed piping systems. Individual flow rates are put into the computer, then computer calculates the pressure drop existing across each component; if needed, design corrections or adjustments can be made and rechecked.

  17. Corrugated Membrane Fuel Cell 2010 DOE Hydrogen Program Fuel Cell

    E-print Network

    .1 Material property data for candidate GDL materials received from tasks 2 and 3 10/11 8 5.2 FEA analysis mOhm-cm2 and >20 psi, p compressive force 5/125/12 6 3 Down-select most promising metal corrugated GDL plate subassembly 5/13 2 & 3 & 5 Go/No-Go: Can corrugated GDL materials give target properties

  18. Emerging heat pipe applications

    Microsoft Academic Search

    A. Basuilis; D. J. Formiller

    1978-01-01

    The article discusses the application of heat pipes in various industrial, military, and space projects. Several types of heat pipes are described, including simple cylindrical heat pipes, switching heat pipes, thermal diodes, variable conductance heat pipes, and vapor chambers. Potential future applications of heat pipes are identified in the fields of electronics, spacecraft thermal control, heat pipe recovery systems, and

  19. Response of corrugated panels to blast loading

    SciTech Connect

    Louca, L.A. [City Univ., London (United Kingdom). Dept. of Civil Engineering; Harding, J.E. [Univ. of Surrey, Guildford (United Kingdom). Dept. of Civil Engineering; White, G.C. [British Gas, Loughborough (United Kingdom). Gas Research Centre

    1996-12-31

    This paper presents results of a preliminary study on the response of stainless steel corrugated panels subjected to hydrocarbon explosions. The panels are typical of those used as firewalls and cladding panels on offshore topside structures. Experimental data obtained from full scale tests carried out by British Gas with peak over pressures exceeding 2 bar are compared with the results of explicit nonlinear finite element analyses. The numerical finite element models account for the effects of large deflection behavior and material nonlinearity with the measured stress strain curve of the material used in the modelling. The effects of weld failure have also been modelled in the analytical study by the use of a simple force based failure criterion. It was found that the effects of variations in the pressure distribution on the panel had a significant influence on the overall response, particularly in predicting the point of weld failure. A complete model of the wall has been used in this study. The results show that the failure process can be predicted in a qualitative manner with the time to failure of the weld being predicted conservatively.

  20. Finite-temperature Casimir force between perfectly metallic corrugated surfaces

    SciTech Connect

    Sarabadani, Jalal; Miri, MirFaez [Department of Physics, University of Isfahan, Isfahan 81746 (Iran, Islamic Republic of); Department of Physics, University of Tehran, P.O. Box 14395-547, Tehran (Iran, Islamic Republic of) and School of Physics, Institute for Research in Fundamental Sciences, (IPM) Tehran 19395-5531 (Iran, Islamic Republic of)

    2011-09-15

    We study the Casimir force between two corrugated plates due to thermal fluctuations of a scalar field. For arbitrary corrugations and temperature T, we provide an analytical expression for the Casimir force, which is exact to second order in the corrugation amplitude. We study the specific case of two sinusoidally corrugated plates with corrugation wavelength {lambda}, lateral displacement b, and mean separation H. We find that the lateral Casimir force is F{sub l}(T,H)sin(2{pi}b/{lambda}). In other words, at all temperatures, the lateral force is a sinusoidal function of the lateral shift. In the limit {lambda}>>H, F{sub l}(T{yields}{infinity},H){proportional_to}k{sub B}TH{sup -4}{lambda}{sup -1}. In the opposite limit {lambda}<

  1. Detection of rail corrugation based on fiber laser accelerometers

    NASA Astrophysics Data System (ADS)

    Huang, Wenzhu; Zhang, Wentao; Du, Yanliang; Sun, Baochen; Ma, Huaixiang; Li, Fang

    2013-09-01

    Efficient inspection methods are necessary for detection of rail corrugation to improve the safety and ride quality of railway operations. This paper presents a novel fiber optic technology for detection of rail corrugation based on fiber laser accelerometers (FLAs), tailored to the measurement of surface damage on rail structures. The principle of detection of rail corrugation using double integration of axle-box acceleration is presented. Then we present the theoretical model and test results of FLAs which are installed on the bogie to detect the vertical axle-box acceleration of the train. Characteristics of high sensitivity and large dynamic range are achieved when using fiber optic interferometric demodulation. A flexible inertial algorithm based on double integration and the wavelet denoising method is proposed to accurately estimate the rail corrugation. A field test is carried out on the Datong-Qinhuangdao Railway in north China. The test results are compared with the results of a rail inspection car, which shows that the fiber laser sensing system has a good performance in monitoring rail corrugation.

  2. Piping Connector

    NASA Technical Reports Server (NTRS)

    1994-01-01

    In Stennis Space Center's Component Test Facility, piping lines carry rocket propellants and high pressure cryogenic fuels. When the lines are chilled to a pretest temperature of 400 degrees below zero, ordinary piping connectors can leak. Under contract to Stennis, Reflange, Inc. developed the T-Con connector, which included a secondary seal that tolerates severe temperature change. Because of the limited need for the large and expensive T-Con product, Reflange also developed the less costly E-Con, a smaller more compact design with the same technical advantages as the T-Con.

  3. Equivalent models of corrugated laminates for morphing skins

    NASA Astrophysics Data System (ADS)

    Xia, Yuying; Friswell, Michael I.

    2011-03-01

    The design of the skins has been identified as a major issue for morphing aircraft wings. Corrugated laminates provide a good solution due to their extremely anisotropic behavior. However, the optimal design of a morphing aircraft requires simple models of the skins that may be incorporated into multi-disciplinary system models. This requires equivalent material models that retain the dependence on the geometric parameters of the corrugated skins. An analytical homogenization model, which could be used for any corrugation shape, is suggested in this paper. This method is based on a simplified geometry for a unit-cell and the stiffness properties of original sheet. This paper investigates such a modeling strategy and demonstrates its performance and potential.

  4. Structural performance of near-optimal sandwich panels with corrugated cores

    E-print Network

    Zok, Frank

    Structural performance of near-optimal sandwich panels with corrugated cores L. Valdevit a , Z. Wei of steel sandwich panels with corrugated cores in both transverse and longitudinal loading orientations has. Keywords: Lightweight structures; Sandwich panels; Corrugated core; Imperfection sensitivity 1

  5. Morphing of curved corrugated shells A.D. Norman, K.A. Seffen

    E-print Network

    Guest, Simon

    Morphing of curved corrugated shells A.D. Norman, K.A. Seffen and S.D. Guest Department-called `morphing' structures that offer both structural integrity and large Corresponding author. Tel: +44 (0 corrugated sheet can be made to morph: the corrugations are flattened transversely and the sheet then deforms

  6. Forced convective heat transfer in cross-corrugated solar air heaters

    Microsoft Academic Search

    Y. Piao; E. G. Hauptmann; M. Iqbal

    1994-01-01

    Forced convective heat transfer in a cross-corrugated channel solar air heater has been studied experimentally using air as a working fluid. The channel was formed by two transversely positioned corrugated sheets and two flat thermally insulated side walls. One corrugated sheet was heated by a radiant heater, while the other was thermally insulated. The fluid velocity and temperature, and the

  7. Unexpected crossover dynamics of single polymer in a corrugated tube

    E-print Network

    A. De Virgiliis; L. Kuban; J. Paturej; D. Mukherji

    2012-09-03

    We present molecular dynamics study of a generic (coarse-grained) model for single-polymer diffusion confined in a corrugated cylinder. For a narrow tube, i.e., diameter of the cylinder $\\delta tube and/or for a cylinder with larger diameter.

  8. Corrugation in Exfoliated Graphene: An Electron Microscopy and Diffraction

    E-print Network

    Kim, Philip

    equally to this work. G raphene, a single monolayer of car- bon atoms arranged in a honey- comb lattice. Graphene shows an ambipolar electric-field effect and an extremely high mobility of charge carriers to image and characterize corrugation in SiO2-supported and suspended exfoliated graphene at nanometer

  9. Optimization of photonics for corrugated thin-film solar cells

    Microsoft Academic Search

    Olivier Deparis; Jean Pol Vigneron; Otto Agustsson; Daniel Decroupet

    2009-01-01

    The amount of solar energy reaching the active (photovoltaic) layer in a thin-film solar cell can be increased by reducing the Fresnel reflection losses at the interfaces. By using corrugated interfaces (at the wavelength scale), adiabatic propagation of the electromagnetic radiation is achieved over a broad wavelength range throughout the structure, which leads to an increase in the light that

  10. CLOSED PROCESS WATER LOOP IN NSSC CORRUGATING MEDIUM MANUFACTURE

    EPA Science Inventory

    Over the last 5 years, the Green Bay Packaging corrugating medium mill has converted to an essentially closed process water system. The mill is a net consumer of water. This is due to the greater amount of water carried out of the system with the sheet compared to the lower water...

  11. Improved coupled mode analysis of corrugated waveguides and lasers

    Microsoft Academic Search

    Y. Yamamoto; T. Kamiya; H. Yanai

    1978-01-01

    Corrugated waveguides and lasers in resonant and non-resonant situations are analyzed by an improved coupled mode theory based on a set of the coupled mode equations for guided modes and radiation continuum. The distributed feedback (DFB) coefficient and the radiation loss coefficient are given in closed forms. The formulation can be applicable to arbitrarily shaped gratings and multilayer waveguide structures.

  12. Pipe failure prediction

    Microsoft Academic Search

    Chun hua Tian; Jing Xiao; Jin Huang; Felipe Albertao

    2011-01-01

    Preventa tive pipe maintenance is a key activity in pipe asset management. Central to such activity is a precise pipe failure (burstJIeakage) prediction. Here a statistical pipe failure prediction approach is proposed based on the massive data including pipe physical property, environmental factor, operational condition, historical failure records, and etc. Considering the biased training cases, survival analysis model is adopted

  13. Heat pipe technology

    NASA Technical Reports Server (NTRS)

    1972-01-01

    A bibliography of heat pipe technology to provide a summary of research projects conducted on heat pipes is presented. The subjects duscussed are: (1) heat pipe applications, (2) heat pipe theory, (3) design and fabrication, (4) testing and operation, (5) subject and author index, and (6) heat pipe related patents.

  14. Porus electrode comprising a bonded stack of pieces of corrugated metal foil

    NASA Technical Reports Server (NTRS)

    Mccallum, J. (inventor)

    1973-01-01

    An electrode suitable for use in an electrochemical cell is described. The electrode is composed of a porous conductive support with a bonded stack of pieces of thin corrugated nickel foil where the corrugations are oriented approximately perpendicular to the sides of the electrode and form an array of passages through the electrode. Active material such as cadmium hydroxide or nickel hydroxide is uniformly distributed within the passages. The support may comprise also a piece of thin flat nickel foil between adjacent pieces of the corrugated foil, forming a barrier between the passages formed on each side of it. Typically the corrugations in the odd corrugated layers are oriented at a small angle from the perpendicular in one direction and the corrugations in the even corrugated layers are oriented at a small angle from the perpendicular in the opposite direction.

  15. Test of superplastically formed corrugated aluminum compression specimens with beaded webs

    NASA Technical Reports Server (NTRS)

    Davis, Randall C.; Royster, Dick M.; Bales, Thomas T.; James, William F.; Shinn, Joseph M., Jr.

    1991-01-01

    Corrugated wall sections provide a highly efficient structure for carrying compressive loads in aircraft and spacecraft fuselages. The superplastic forming (SPF) process offers a means to produce complex shells and panels with corrugated wall shapes. A study was made to investigate the feasibility of superplastically forming 7475-T6 aluminum sheet into a corrugated wall configuration and to demonstrate the structural integrity of the construction by testing. The corrugated configuration selected has beaded web segments separating curved-cap segments. Eight test specimens were fabricated. Two specimens were simply a single sheet of aluminum superplastically formed to a beaded-web, curved-cap corrugation configuration. Six specimens were single-sheet corrugations modified by adhesive bonding additional sheet material to selectively reinforce the curved-cap portion of the corrugation. The specimens were tested to failure by crippling in end compression at room temperature.

  16. Condensation of refrigerants flowing inside smooth and corrugated tubes

    SciTech Connect

    Hinton, D.L. [Tennessee State Univ., Nashville, TN (United States); Conklin, J.C.; Vineyard, E.A. [Oak Ridge National Lab., TN (United States)

    1995-07-01

    Because heat exchanger thermal performance has a direct fluence on the overall cycle performance of vapor-compression refrigeration machinery,enhanced heat transfer surfaces are of interest to improve the efficiency of heat pumps and air conditioners. We investigated R-22 and a nonazeotropic refrigerant mixture (NARM) of 75% R-143a and 25% R-124 (by mass) to study their thermal performance in a condenser made of conventional smooth tubes and another condenser made of corrugated, or spirally indented, tubes. We investigated the condensing heat transfer and pressure drop characteristics in an experimental test loop model of a domestic beat pump system employing a variable speed compressor. The refrigerant circulates inside the central tube and the water circulates in the annulus. At refrigerant mass fluxes of approximately 275--300 kg/m{sup 2}s, the measured irreversible pressure drop of the corrugated surface was 23% higher than that of the smooth surface for the R-22. At refrigerant mass fluxes of 350-370 kg/m{sup 2}s, the irreversible pressure drop of the corrugated surface was 36% higher than that of the smooth surface for the NARM. The average heat transfer coefficient for the corrugated surface for R-22 was roughly 40% higher than that for the smooth tube surface at refrigerant mass fluxes of 275--295 kg/m{sup 2}s. The average heat transfer coefficient for the corrugated surface for the NARM was typically 70% higher than that for the smooth tube surface at refrigerant mass fluxes of 340--385 kg/m{sup 2}s.

  17. Hydrogen sulfide removal from sediment and water in box culverts/storm drains by iron-based granules.

    PubMed

    Sun, J L; Shang, C; Kikkert, G A

    2013-01-01

    A renewable granular iron-based technology for hydrogen sulfide removal from sediment and water in box culverts and storm drains is discussed. Iron granules, including granular ferric hydroxide (GFH), granular ferric oxide (GFO) and rusted waste iron crusts (RWIC) embedded in the sediment phase removed aqueous hydrogen sulfide formed from sedimentary biological sulfate reduction. The exhausted iron granules were exposed to dissolved oxygen and this regeneration process recovered the sulfide removal capacities of the granules. The recovery is likely attributable to the oxidation of the ferrous iron precipitates film and the formation of new reactive ferric iron surface sites on the iron granules and sand particles. GFH and RWIC showed larger sulfide removal capacities in the sediment phase than GFO, likely due to the less ordered crystal structures on their surfaces. This study demonstrates that the iron granules are able to remove hydrogen sulfide from sediment and water in box culverts and storm drains and they have the potential to be regenerated and reused by contacting with dissolved oxygen. PMID:24355850

  18. Progress Toward Corrugated Feed Horn Arrays in Silicon

    SciTech Connect

    Britton, J.; Yoon, K. W.; Beall, J. A.; Becker, D.; Cho, H. M.; Hilton, G. C.; Niemack, M. D.; Irwin, K. D. [Quantum Sensors Group, NIST, Boulder, CO 80305 (United States)

    2009-12-16

    We are developing monolithic arrays of corrugated feed horns fabricated in silicon for dual-polarization single-mode operation at 90, 145 and 220 GHz. The arrays consist of hundreds of platelet feed horns assembled from gold-coated stacks of micro-machined silicon wafers. As a first step, Au-coated Si waveguides with a circular, corrugated cross section were fabricated; their attenuation was measured to be less than 0.15 dB/cm from 80 to 110 GHz at room temperature. To ease the manufacture of horn arrays, electrolytic deposition of Au on degenerate Si without a metal seed layer was demonstrated. An apparatus for measuring the radiation pattern, optical efficiency, and spectral band-pass of prototype horns is described. Feed horn arrays made of silicon may find use in measurements of the polarization anisotropy of the cosmic microwave background radiation.

  19. Corrugated interfaces in multiphase core-annular flow

    NASA Astrophysics Data System (ADS)

    Shum, Ho Cheung; Sauret, Alban; Fernandez-Nieves, Alberto; Stone, Howard A.; Weitz, David A.

    2010-08-01

    Microfluidic devices can be used to produce highly controlled and monodisperse double or multiple emulsions. The presence of inner drops inside a jet of the middle phase introduces deformations in the jet, which leads to breakup into monodisperse double emulsions. However, the ability to generate double emulsions can be compromised when the interfacial tension between the middle and outer phases is low, leading to flow with high capillary and Weber numbers. In this case, the interface between the fluids is initially deformed by the inner drops but the jet does not break into drops. Instead, the jet becomes highly corrugated, which prevents formation of controlled double emulsions. We show using numerical calculations that the corrugations are caused by the inner drops perturbing the interface and the perturbations are then advected by the flow into complex shapes.

  20. Optimization of a corrugated stiffened composite panel under uniaxial compression

    NASA Technical Reports Server (NTRS)

    Agarwal, B. L.; Sobel, L. H.

    1973-01-01

    An approach of structural optimization has been used to optimize the weight of a simply supported, corrugated hat stiffened composite panel under uniaxial compression. The approach consists of the employment of nonlinear mathematical programming techniques to reach an optimum solution. Some simplifying assumptions are made in the stress analysis to obtain faster convergence to an optimum solution. With these simplifying assumptions the number of unknown design parameters is reduced to twelve.

  1. Directional terahertz emission from corrugated InAs structures

    NASA Astrophysics Data System (ADS)

    Yim, Jong-Hyuk; Jeong, Hoonil; Irfan, Muhammad; Lee, Eun-Hye; Song, Jin-Dong; Jho, Young-Dahl

    2013-08-01

    We have designed and fabricated a new type of terahertz (THz) emitter that radiates THz waves along the surface-normal direction because of the lateral distributions of the transient electric dipoles. The excitation and measurements were performed using a conventional THz time-domain spectroscopy scheme with femtosecond optical pulses. The corrugated mirror patterns on the InAs layers made the radiation directional along the surface-normal direction, and the emission efficiency was controlled by adjustment of the pattern width.

  2. Corrugated outer sheath gas-insulated transmission line

    DOEpatents

    Kemeny, George A. (Pittsburgh, PA); Cookson, Alan H. (Churchill Boro, PA)

    1981-01-01

    A gas-insulated transmission line includes two transmission line sections each of which are formed of a corrugated outer housing enclosing an inner high-voltage conductor disposed therein, with insulating support means supporting the inner conductor within the outer housing and an insulating gas providing electrical insulation therebetween. The outer housings in each section have smooth end sections at the longitudinal ends thereof which are joined together by joining means which provide for a sealing fixed joint.

  3. Interaction of streamers and stationary corrugated ionization waves in semiconductors.

    PubMed

    Kyuregyan, A S

    2014-04-01

    A numerical simulation of evolution of an identical interacting streamers array in semiconductors has been performed using the diffusion-drift approximation and taking into account the impact and tunnel ionization. It has been assumed that the external electric field E0 is static and uniform, the background electrons and holes are absent, the initial avalanches start simultaneously from the nodes of the plane hexagonal lattice, which is perpendicular to the external field, but the avalanches and streamers are axially symmetric within a cylinder of radius R. It has been shown that under certain conditions, the interaction between the streamers leads finally either to the formation of two types of stationary ionization waves with corrugated front or to a stationary plane ionization wave. A diagram of different steady states of this type of waves in the plane of parameter E0,R has been presented, and a qualitative explanation of the plane partition into four different regions has been given. Characteristics of corrugated waves have been studied in detail and discussed in the region of R and E0 large values, in which the maximum field strength at the front is large enough for the tunnel ionization implementation. It has been shown that corrugated waves ionize semiconductors more efficiently than flat ones, especially in relatively weak external fields. PMID:24827322

  4. Evaporation characteristics of R22 flowing inside a corrugated tube

    SciTech Connect

    Hinton, D.L. [Tennessee State Univ., Nashville, TN (United States); Conklin, J.C.; Vineyard, E.A. [Oak Ridge National Lab., TN (United States)

    1992-07-01

    Because heat exchanger thermal performance has a direct influence on the overall cycle performance of vapor-compression refrigeration machinery, enhanced heat transfer surfaces are of interest to improve the efficiency of heat pumps and air conditioners. As part of a larger program investigating nonazeotropic refrigerant mixtures for replacement of chlorofluorocarbon compounds, we investigated the performance of R22 (chlorodifluoromethane) in conventional smooth tubes and enhanced heat transfer tube geometries as a base case. This paper presents the results of this initial investigation for a smooth tube and a tube with a commonly available enhanced heat transfer surface, called corrugated or spirally indented. We investigated the evaporating heat transfer and pressure drop characteristics in an experimental apparatus consisting of a variable-speed compressor and two sets of counterflow concentric-tube heat exchangers having both smooth and corrugated enhanced tubeside surfaces. The refrigerant circulates inside the central tube and water circulates in the annulus. The measured pressure drop and the heat transfer coefficient for the evaporation of the R22 are presented as a function of heat flux, quality, and mass flux for both heat transfer surfaces. Both the heat transfer coefficient and the pressure drop of the corrugated surface are higher than those of the smooth surface at any given refrigerant condition. The heat transfer enhancement is most notable at low mass qualities.

  5. PROCESSING OF NANOSTRUCTURED COPPER BY REPETITIVE CORRUGATION AND STRAIGHTENING (RCS)

    SciTech Connect

    Zhu, Y.T.; Jiang, H. [and others

    2000-10-01

    A new process, Repetitive Corrugation and Straightening (RCS), has been developed to create bulk, nanostructured copper. In this investigation, a high purity (99.99%). copper bar measuring 6 x 6 x 50 mm with an average grain size of 765 {micro}m was used as the starting material. It was repetitively corrugated and straightened for 14 times with 90{degree} rotations along its longitudinal axis between consecutive corrugation-straightening cycles. The copper was cooled to below room temperature before each RCS cycle. The grain size obtained after the RCS process was in the range of twenty to a few hundred nanometers, and microhardness was increased by 100%. Both equilibrium and non-equilibrium grain boundaries are observed. This work demonstrates the capability of the RCS process in refining grain size of metal materials. The RCS process can be easily adapted to large-scale industrial production and has the potential to pave the way to large-scale structural applications of nanostructured materials.

  6. Transient coexisting nanophases in ultrathin films confined between corrugated walls

    SciTech Connect

    Curry, J.E.; Zhang, F.; Cushman, J.H. (Lilly Hall of Life Sciences, Purdue University, West Lafayette, Indiana 47907 (United States)); Schoen, M. (Institut fuer Theoretische Physik, Technische Universitaet Berlin, Hardenbergstr. 36, 10623 Berlin (Germany)); Diestler, D.J. (Department of Agronomy, Keim Hall, University of Nebraska-Lincoln, Lincoln, Nebraska 68583-0915 (United States))

    1994-12-15

    Grand-canonical Monte Carlo and microcanonical molecular dynamics methods have been used to simulate an ultrathin monatomic film confined to a slit-pore [i.e., between solid surfaces (walls)]. Both walls comprise atoms rigidly fixed in the face centered cubic (100) configuration; one wall is smooth on a nanoscale and the other is corrugated (i.e., scored with regularly spaced rectilinear grooves one to several nanometers wide). Properties of the film have been computed as a function of the lateral alignment (registry), with the temperature, chemical potential, and distance between the walls kept constant. Changing the registry carries the film through a succession of equilibrium states, ranging from all solid at one extreme to all fluid at the other. Over a range of intermediate registries the film consists of fluid and solid portions in equilibrium, that is fluid-filled nanocapillaries separated by solid strips. The range of registries over which such fluid--solid equilibria exist depends upon the width of the grooves and the frequency of the corrugation. For grooves of width comparable to the range of the interatomic potential, fluid and solid phases cease to coexist. In the limit of very wide grooves the character of the film is similar to that of the film confined by strictly smooth walls. The rich phase behavior of the confined film due to the coupling between molecular (registry) and nano (corrugation) scales has obvious implications for boundary lubrication.

  7. Pipe protection bibliography

    Microsoft Academic Search

    1987-01-01

    Pipes and pipelines are being used for an ever widening range of materials, for increasing flows and in harsher applications. There is also more legal and social pressure to reduce the hazards associated with handling materials in pipes. All of this increases the demand for improved pipe reliability. Two of the major preventable causes of pipe failure are corrosion and

  8. Experimental Investigation of the Strength of Multiweb Beams with Corrugated Webs

    NASA Technical Reports Server (NTRS)

    Fraser, Allister F

    1956-01-01

    The results of an experimental investigation of the strength of multiweb beams with corrugated webs are reported. Included in the investigation were two types of connection between the web and the skin. A comparison between the structural efficiency of corrugated-web and channel-web multiweb beams is presented, and it is shown that, for a considerable range of the structural index, corrugated-web beams can be built which are structurally more efficient than channel-web beams.

  9. Surveying drainage culvert use by carnivores: sampling design and cost-benefit analyzes of track-pads vs. video-surveillance methods.

    PubMed

    Mateus, Ana Rita A; Grilo, Clara; Santos-Reis, Margarida

    2011-10-01

    Environmental assessment studies often evaluate the effectiveness of drainage culverts as habitat linkages for species, however, the efficiency of the sampling designs and the survey methods are not known. Our main goal was to estimate the most cost-effective monitoring method for sampling carnivore culvert using track-pads and video-surveillance. We estimated the most efficient (lower costs and high detection success) interval between visits (days) when using track-pads and also determined the advantages of using each method. In 2006, we selected two highways in southern Portugal and sampled 15 culverts over two 10-day sampling periods (spring and summer). Using the track-pad method, 90% of the animal tracks were detected using a 2-day interval between visits. We recorded a higher number of crossings for most species using video-surveillance (n = 129) when compared with the track-pad technique (n = 102); however, the detection ability using the video-surveillance method varied with type of structure and species. More crossings were detected in circular culverts (1 m and 1.5 m diameter) than in box culverts (2 m to 4 m width), likely because video cameras had a reduced vision coverage area. On the other hand, carnivore species with small feet such as the common genet Genetta genetta were detected less often using the track-pad surveying method. The cost-benefit analyzes shows that the track-pad technique is the most appropriate technique, but video-surveillance allows year-round surveys as well as the behavior response analyzes of species using crossing structures. PMID:21181260

  10. Open-ended Coaxial Cavities with Corrugated Inner and Outer Walls

    NASA Astrophysics Data System (ADS)

    Ioannidis, Zisis C.; Avramidis, Konstantinos A.; Tigelis, Ioannis G.

    2015-05-01

    In this work an open-ended coaxial cavity with a corrugated insert and a relatively small number of corrugations on the outer wall is studied. In particular, the Spatial Harmonics Method (SHM) is employed in order to derive the TE modes characteristic equation, which is then solved by truncation for the calculation of the corresponding eigenvalues. Special care is given in the expansion functions used in order to avoid numerical instabilities in the calculation of high-order spatial terms. Various cases of outer wall corrugations are studied numerically in order to identify the effect of the outer corrugations and understand the mode coupling mechanism.

  11. Numerical exploration of the origin of aerodynamic enhancements in [low-Reynolds number] corrugated airfoils

    NASA Astrophysics Data System (ADS)

    Barnes, Caleb J.; Visbal, Miguel R.

    2013-11-01

    This paper explores the flow structure of a corrugated airfoil using a high-fidelity implicit large eddy simulation approach. The first three-dimensional simulations for a corrugated wing section are presented considering a range of Reynolds numbers of Rec = 5 × 103 to 5.8 × 104 bridging the gap left by previous numerical and experimental studies. Several important effects are shown to result from the corrugations in the leading-edge region. First, interaction between the detached shear layer and the first corrugation peak promotes recirculation upstream and enhances transition to turbulence due to flow instabilities. Thus, early transitional flow develops on the corrugated wing which helps to delay stall even at Reynolds numbers as low as Rec = 1 × 104. Transition is shown to occur as early as Rec = 7.5 × 103 and quickly advances toward the leading-edge as Reynolds number is increased. Modification of the first corrugation peak height produces significantly reduced separation and improved aerodynamic forces demonstrating the sensitivity of flow behavior to leading-edge geometry. Second, the unusual orientation of the corrugated surface and strong suction resulting from rapidly turning fluid over the separated region upstream of the first corrugation produces a new effect which serves to reduce drag. This effect was amplified through the enhanced interaction produced by a modified geometry. Corrugations were found to be most advantageous in the leading-edge region and could be optimized to properly take advantage of the flow field under different operating conditions.

  12. Assessment of scour-critical data collected at selected bridges and culverts in South Carolina, 1990-92

    USGS Publications Warehouse

    Hurley, N.M., Jr.

    1996-01-01

    Data at bridges and culverts were collected at 3,506 stream crossings in South Carolina during 1990-92. The data include general information unique to the structure; structural data; and hydraulic, geomorphic, and vegetation information. The data are stored in the U.S. Geological Survey South Carolina District Bridge-Scour Data Base. Observed- and potential-scour indexes were computed from the applicable data variables. Sites with observed-scour indexes exceeding ten and (or) potential-scour indexes exceeding 20 are considered to have significant scour-related problems. Of the 3,506 sites inspected, 257 sites had an observed-scour index exceeding ten, 214 sites had a potential-scour index exceeding 20, and 85 sites had observed- and potential-scour indexes exceeding both threshold values.

  13. Insulated pipe clamp design

    SciTech Connect

    Anderson, M.J.; Hyde, L.L.; Wagner, S.E.; Severud, L.K.

    1980-01-01

    Thin wall large diameter piping for breeder reactor plants can be subjected to significant thermal shocks during reactor scrams and other upset events. On the Fast Flux Test Facility, the addition of thick clamps directly on the piping was undesired because the differential metal temperatures between the pipe wall and the clamp could have significantly reduced the pipe thermal fatigue life cycle capabilities. Accordingly, an insulated pipe clamp design concept was developed. The design considerations and methods along with the development tests are presented. Special considerations to guard against adverse cracking of the insulation material, to maintain the clamp-pipe stiffness desired during a seismic event, to minimize clamp restraint on the pipe during normal pipe heatup, and to resist clamp rotation or spinning on the pipe are emphasized.

  14. Flexible ocean upwelling pipe

    DOEpatents

    Person, Abraham (Los Alamitos, CA)

    1980-01-01

    In an ocean thermal energy conversion facility, a cold water riser pipe is releasably supported at its upper end by the hull of the floating facility. The pipe is substantially vertical and has its lower end far below the hull above the ocean floor. The pipe is defined essentially entirely of a material which has a modulus of elasticity substantially less than that of steel, e.g., high density polyethylene, so that the pipe is flexible and compliant to rather than resistant to applied bending moments. The position of the lower end of the pipe relative to the hull is stabilized by a weight suspended below the lower end of the pipe on a flexible line. The pipe, apart from the weight, is positively buoyant. If support of the upper end of the pipe is released, the pipe sinks to the ocean floor, but is not damaged as the length of the line between the pipe and the weight is sufficient to allow the buoyant pipe to come to a stop within the line length after the weight contacts the ocean floor, and thereafter to float submerged above the ocean floor while moored to the ocean floor by the weight. The upper end of the pipe, while supported by the hull, communicates to a sump in the hull in which the water level is maintained below the ambient water level. The sump volume is sufficient to keep the pipe full during heaving of the hull, thereby preventing collapse of the pipe.

  15. Aerodynamic effects of wing corrugation at gliding flight at low Reynolds numbers

    NASA Astrophysics Data System (ADS)

    Meng, Xue Guang; Sun, Mao

    2013-07-01

    Corrugation gives an insect-wing the advantages of low mass, high stiffness, and low membrane stress. Researchers are interested to know if it is also advantageous aerodynamically. Previous works reported that corrugation enhanced the aerodynamic performance of wings at gliding flight. However, Reynolds numbers considered in these studies were higher than that of gliding insects. The present study showed that in the Reynolds number range of gliding insects, corrugation had negative aerodynamic effects. We studied aerodynamic effects of corrugation at gliding motion using the method of computational fluid dynamics, in the Reynolds number range of Re = 200-2400. Different corrugation patterns were considered. The effect of corrugation on aerodynamic performance was identified by comparing the aerodynamic forces between the corrugated and flat-plate wings, and the underlying flow mechanisms of the corrugation effects were revealed by analyzing the flow fields and surface pressure distributions. The findings are as follows: (1) the effect of corrugation is to decrease the lift, and change the drag only slightly (at 15°-25° angles of attack, lift is decreased by about 16%; at smaller angles of attack, the percentage of lift reduction is even larger because the lift is small). (2) Two mechanisms are responsible for the lift reduction. One is that the pleats at the lower surface of the corrugated wing produce relatively strong vortices, resulting in local low-pressure regions on the lower surface of the wing. The other is that corrugation near the leading edge pushes the leading-edge-separation layer slightly upwards and increases the size of the separation bubble above the upper surface, reducing the "suction pressure," or increasing the pressure, on the upper surface.

  16. Using Flexible Pipe (poly-pipe) with Surface Irrigation 

    E-print Network

    Peries, Xavier; Enciso, Juan

    2005-10-05

    Aimed at farmers and irrigators who want to irrigate their crops using flexible plastic pipes (commonly called "poly-pipe), this publication highlights (1) advantages of using poly-pipe, (2) factors to consider in selecting such pipe, and (3...

  17. INTERIOR VIEW WITH PIPE CASTING MACHINE CASTING A 24' PIPE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW WITH PIPE CASTING MACHINE CASTING A 24' PIPE AND OPERATOR JOHNNY NIXON. - United States Pipe & Foundry Company Plant, Pipe Casting & Testing Area, 2023 St. Louis Avenue at I-20/59, Bessemer, Jefferson County, AL

  18. INTERIOR VIEW WITH PIPE CASTING MACHINE EXTRUDING A 24' PIPE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW WITH PIPE CASTING MACHINE EXTRUDING A 24' PIPE AND OPERATOR JOHNNY NIXON. - United States Pipe & Foundry Company Plant, Pipe Casting & Testing Area, 2023 St. Louis Avenue at I-20/59, Bessemer, Jefferson County, AL

  19. The manufacture of corrugated copper tubes with a Nb3Sn layer

    Microsoft Academic Search

    G. I. Meshchanov; I. B. Peshkov; G. G. Savalo; P. Rohner; G. Ziemek

    1985-01-01

    Based on prior experience gained with superconducting materials, further research work was jointly carried out by our organizations. The purpose of this effort was the establishment of a production process for the manufacture of corrugated, high-purity copper tubes incorporating the thickest possible layers of superconducting NbâSn. The goal of the production process was to develop a corrugated, bendable superconductor as

  20. Phonon Heat Conduction in Corrugated Silicon Nanowires Below the Casimir Limit Christophe Blanc,1

    E-print Network

    , 2013) The thermal conductance of straight and corrugated monocrystalline silicon nanowires has beenPhonon Heat Conduction in Corrugated Silicon Nanowires Below the Casimir Limit Christophe Blanc,1. This result suggests an original approach to transforming a monocrystalline material into a phonon glass. PACS

  1. Phonon Heat Conduction in Corrugated Silicon Nanowires Below the Casimir Limit Christophe Blanc,1

    E-print Network

    Paris-Sud XI, Université de

    , 2013) The thermal conductance of straight and corrugated monocrystalline silicon nanowires has beenPhonon Heat Conduction in Corrugated Silicon Nanowires Below the Casimir Limit Christophe Blanc,1 an original approach to transforming a monocrystalline material into a phonon glass. PACS numbers: 63.22.-m

  2. Surface-plasmon cross coupling in molecular fluorescence near a corrugated thin metal film

    NASA Technical Reports Server (NTRS)

    Gruhlke, R. W.; Holland, W. R.; Hall, D. G.

    1968-01-01

    Surface plasmons on opposite sides of a thin metal film can cross couple in the presence of a surface corrugation, or grating. The observation of this cross-coupling phenomenon as a radiative-decay mechanism for molecules near a corrugated thin metal film is reported.

  3. Linear theory of electromagnetic wave generation in a plasma-loaded corrugated-wall resonator

    Microsoft Academic Search

    K. Minami; Yuval Carmel; V. L. Granatstein; William W. Destler; Weiran Lou; D. K. Abe; R. A. Kehs; M. M. Ali; T. Hosokawa; K. Ogura; T. Watanabe

    1990-01-01

    A linear theory of the excitation of electromagnetic waves in a plasma-filled corrugated-wall waveguide with an arbitrarily large sinusoidal corrugation has been derived and analyzed numerically. The theory predicts that, when driven by an electron beam, the presence of a plasma in the slow wave structure will cause an increase in the oscillation frequency, and that the temporal growth rates

  4. On the isothermal geometry of corrugated graphene sheets

    E-print Network

    Andrzej Trzesowski

    2014-12-22

    Variational geometries describing corrugated graphene sheets are proposed. The isothermal thermomechanical properties of these sheets are described by a 2-dimensional Weyl space. The equation that couples the Weyl geometry with isothermal distributions of the temperature of graphene sheets, is formulated. This material space is observed in a 3-dimensional orthogonal configurational point space as regular surfaces which are endowed with a thermal state vector field fulfilling the isothermal thermal state equation. It enables to introduce a non-topological dimensionless thermal shape parameter of non-developable graphene sheets. The properties of the congruence of lines generated by the thermal state vector field are discussed.

  5. The Flow of Newtonian Fluids in Axisymmetric Corrugated Tubes

    E-print Network

    Taha Sochi

    2010-06-08

    This article deals with the flow of Newtonian fluids through axially-symmetric corrugated tubes. An analytical method to derive the relation between volumetric flow rate and pressure drop in laminar flow regimes is presented and applied to a number of simple tube geometries of converging-diverging nature. The method is general in terms of fluid and tube shape within the previous restrictions. Moreover, it can be used as a basis for numerical integration where analytical relations cannot be obtained due to mathematical difficulties.

  6. Impedance of a Beam Tube with Small Corrugations

    SciTech Connect

    Bane, Karl LF

    2000-09-01

    In accelerator projects involving the use of very short bunches, such as the Linac Coherent Light Source (LCLS)--where the rms bunch length in the undulator section is 30-microns--it appears that even submicron imperfections in the beam tube surface can generate an impedance that is unacceptably large. The authors consider two periodic models of an imperfect, rough surface, one with small rectangular corrugations, the other with smooth sinusoidal oscillations. They compare the impedance of these two models, and apply the results to the LCLS parameters.

  7. Pipe Insulation Economies 

    E-print Network

    Schilling, R. E.

    1986-01-01

    Pipe Insulation Economies is a computer program written in IBM basic to simplify the economic insulation thickness for an insulated pipe. Many articles have been written on this subject, from simple nomographs to a small book written in 1976...

  8. Geysering inhibitor pipe

    NASA Technical Reports Server (NTRS)

    Howard, F. S.

    1973-01-01

    Smaller concentric pipe is welded to main pipe beginning above bottom of isolation valve and terminating in storage tank at top. There is continuous circulation of fluid which maintains fluid temperature below boiling temperature of liquid oxygen.

  9. Underground piping handbook

    Microsoft Academic Search

    Peggs

    1985-01-01

    This book provides the information required to design and prepare construction drawings, and to install, inspect, test, and commission buried piping. Both pressure and gravity piping are covered, including water, steam, gases, and sewers. Directed primarily toward underground industrial piping systems, this is a succinct, well-organized compilation of practical knowledge. Checklists, examples, tables, charts, nomographs, short cuts, and helpful hints

  10. Ceramic heat pipe development

    NASA Astrophysics Data System (ADS)

    Merrigan, M.

    1980-12-01

    Progress in developing ceramic heat pipe recuperators for recovering heat from industrial processing furnaces is reported. Information is included on the design, materials procurement, fabrication, materials testing, performance testing, performance and cost of ceramic heat pipes, especially tungsten-coated silicon carbide and Sic-W-Mo heat pipes.

  11. Ceramic heat pipe development

    Microsoft Academic Search

    M. Merrigan

    1980-01-01

    Progress in developing ceramic heat pipe recuperators for recovering heat from industrial processing furnaces is reported. Information is included on the design, materials procurement, fabrication, materials testing, performance testing, performance and cost of ceramic heat pipes, especially tungsten-coated silicon carbide and Sic-W-Mo heat pipes.

  12. Heat pipe technology issues

    Microsoft Academic Search

    M. A. Merrigan

    1984-01-01

    Critical high temperature, high power applications in space nuclear power designs are near the current state of the art of heat pipe technology in terms of power density, operating temperature, and lifetime. Recent heat pipe development work at Los Alamos National Laboratory involved performance testing of typical space reactor heat pipe designs to power levels in excess of 19 kW\\/cm(2)

  13. Imaging Local Electronic Corrugations and Doped Regions in Graphene

    SciTech Connect

    B Schultz; C Patridge; V Lee; C Jaye; P Lysaght; C Smith; J Barnett; D Fischer; D Prendergast; S Banerjee

    2011-12-31

    Electronic structure heterogeneities are ubiquitous in two-dimensional graphene and profoundly impact the transport properties of this material. Here we show the mapping of discrete electronic domains within a single graphene sheet using scanning transmission X-ray microscopy in conjunction with ab initio density functional theory calculations. Scanning transmission X-ray microscopy imaging provides a wealth of detail regarding the extent to which the unoccupied levels of graphene are modified by corrugation, doping and adventitious impurities, as a result of synthesis and processing. Local electronic corrugations, visualized as distortions of the {pi}*cloud, have been imaged alongside inhomogeneously doped regions characterized by distinctive spectral signatures of altered unoccupied density of states. The combination of density functional theory calculations, scanning transmission X-ray microscopy imaging, and in situ near-edge X-ray absorption fine structure spectroscopy experiments also provide resolution of a longstanding debate in the literature regarding the spectral assignments of pre-edge and interlayer states.

  14. Simulation of terahertz generation in corrugated plasma waveguides

    SciTech Connect

    Pearson, Andrew J.; Palastro, John; Antonsen, Thomas M. [Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742 (United States)

    2011-05-15

    We simulate the response of a corrugated plasma channel to an ultrashort laser pulse in two dimensions with the goal of demonstrating the production of terahertz frequency electromagnetic modes. Corrugated channels support electromagnetic modes that have a Floquet-type dispersion relation and thus consist of a sum of spatial harmonics with subluminal phase velocities. This allows the possibility of phase matching between the ponderomotive potential associated with the laser pulse and the electromagnetic modes of the channel. Since the bandwidth of an ultrashort pulse includes terahertz frequencies, significant excitation of terahertz radiation is possible. Here we consider realistic density profiles to obtain predictions of the terahertz power output and mode structure for a channel with periodic boundary conditions. We then estimate pulse depletion effects from our simulation results. The fraction of laser energy converted to terahertz is independent of laser pulse energy in the linear regime, and we find it to be around 1%. Extrapolating to a pulse energy of 0.5 J gives a terahertz power output of 6 mJ with a pulse depletion length of less than 20 cm.

  15. A comprehensive track model for the improvement of corrugation models

    NASA Astrophysics Data System (ADS)

    Gómez, J.; Vadillo, E. G.; Santamaría, J.

    2006-06-01

    This paper presents a detailed model of the railway track based on wave propagation, suitable for corrugation studies. The model analyses both the vertical and the transverse dynamics of the track. Using the finite strip method (FSM), only the cross-section of the rail must be meshed, and thus it is not necessary to discretise a whole span in 3D. This model takes into account the discrete nature of the support, introducing concepts pertaining to the theory of periodic structures in the formulation. Wave superposition is enriched taking into account the contribution of residual vectors. In this way, the model obtains accurate results when a finite section of railway track is considered. Results for the infinite track have been compared against those presented by Gry and Müller. Aside from the improvements provided by the model presented in this paper, which Gry's and Müller's models do not contemplate, the results arising from the comparison prove satisfactory. Finally, the calculated receptances are compared against the experimental values obtained by the authors, demonstrating a fair degree of adequacy. Finally, these receptances are used within a linear model of corrugation developed by the authors.

  16. Colossal Corrugations in Freestanding Graphene Observed with STM

    NASA Astrophysics Data System (ADS)

    Thibado, P. M.; Xu, P.; Yang, Y.; Barber, S. D.; Ackerman, M. L.; Schoelz, J. K.; Barraza-Lopez, Salvador; Bellaiche, L.; Kornev, Igor A.

    2012-02-01

    The discovery of graphene, a unique two-dimensional electron system with extraordinary physical properties, has ignited tremendous research activity in both science and technology. Graphene interactions with a substrate, such as SiO2/Si, are known to significantly degrade the electrical performance of graphene devices. Alternatively, suspending a graphene device eliminates the substrate interaction, thereby yielding a 10-fold increase in mobility. However, a detailed investigation on the microscopic scale explaining the origin of these improvements has yet to be completed. In this talk, we present for the first time atomic-resolution STM images of a freestanding graphene membrane. Samples were prepared by direct CVD growth and by large graphene sheet transfer, both onto a 2000-mesh copper grid. Atomic-scale corrugation amplitudes were observed in perfect registry with, yet 50 times larger than the expected electronic corrugations. Density functional theory revealed that charge localization occurs directly beneath the STM tip due to bond angles rotating away from sp^2 hybridization as graphene flexes in response to the electrostatic attraction. A detailed model of the 3-way interaction which accounts for the observed behavior will be discussed.

  17. Flood magnitude and frequency of Black Creek at the culvert on New Jersey Route 94, Vernon Township, Sussex County, New Jersey

    USGS Publications Warehouse

    Barringer, T.H.

    1996-01-01

    The magnitude and frequency of floods at Black Creek tributary at the culvert on New Jersey Route 94 at milepost 43.0 in Vernon Township, New Jersey, were determined by using the New Jersey Department of Environmental Protection Special Report 38 method. Estimates of flood magnitude and frequency calculated by the Special Report 38 method, as well as drainage-basin characteristics, are included in this report. The 100-year-flood estimate is 261 cubic feet per second.

  18. Flood magnitude and frequency of Little Timber Creek at the culvert on Interstate Route 295, Haddon Heights Township, Camden County, New Jersey

    USGS Publications Warehouse

    Barringer, T.H.

    1996-01-01

    The magnitude and frequency of floods at the Little Timber Creek at the culvert on Interstate 295, at milepost 28.9, in Haddon Heights Township, New Jersey, were determined by using the New Jersey Department of Environmental Protection Special Report 38 method. Flood-magnitude and -frequency estimates, as well as drainage-basin characteristics, are included in this report. The 100-year-flood estimate is 770 cubic feet per second.

  19. Pipe Line Control

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The array of tanks, pipes and valves in the photo below is a petroleum tank farm in Georgia, part of a petrochemical pipe line system that moves refined petroleum products from Texas and Louisiana to the mid-Eastern seaboard. The same pipes handle a number of different products, such as gasoline, kerosene, jet fuel or fuel oil. The fluids are temporarily stored in tanks, pumped into the pipes in turn and routed to other way stations along the pipe line. The complex job of controlling, measuring and monitoring fuel flow is accomplished automatically by a computerized control and communications system which incorporates multiple space technologies.

  20. Modeling of a corrugated dielectric elastomer actuator for artificial muscle applications

    NASA Astrophysics Data System (ADS)

    Kadooka, Kevin; Taya, Minoru; Naito, Keishi; Saito, Makoto

    2015-04-01

    Dielectric elastomer actuators have many advantages, including light weight, simplicity, high energy density, and silent operation. These features make them suitable to replace conventional actuators and transducers, especially in artificial muscle applications where large contractile strains are necessary for lifelike motions. This paper will introduce the concept of a corrugated dielectric elastomer actuator (DEA), which consists of dielectric elastomer (DE) laminated to a thin elastic layer to induce bending motion at each of the corrugations, resulting in large axial deformation. The location of the DE and elastic layers can be configured to provide tensile or compressive axial strain. Such corrugated DE actuators are also highly scalable: linking multiple actuators in series results in greater deformation, whereas multiple actuators in parallel results in larger force output. Analytical closed-form solutions based on linear elasticity were derived for the displacement and force output of curved unimorph and corrugated DEA, both consisting of an arbitrary number of lamina. A total strain energy analysis and Castigiliano's theorem were used to predict the nonlinear force-displacement behavior of the corrugated actuator. Curved unimorph and corrugated DEA were fabricated using VHB F9469PC as the DE material. Displacement of the actuators observed during testing agreed well with the modeling results. Large contractile strain (25.5%) was achieved by the corrugated DEA. Future work includes investigating higher performance DE materials such as plasticized PVDF terpolymers, processed by thin film deposition methods.

  1. Research on a 170 GHz, 2 MW coaxial cavity gyrotron with inner-outer corrugation

    NASA Astrophysics Data System (ADS)

    Hou, Shenyong; Yu, Sheng; Li, Hongfu

    2015-03-01

    In this paper, a coaxial cavity gyrotron with inner-outer corrugation is researched. The electron kineto-equations and the first order transmission line equations of the gyrotron are derived from Lorentz force equation and the transmission line theory, respectively. And then, a 2 MW, 170 GHz coaxial cavity gyrotron with inner-outer corrugation is designed. By means of numerical calculation, the beam-wave interaction of the coaxial cavity gyrotron with inner-outer corrugation is investigated. Results show that the efficient and the outpower of the gyrotron are 42.3% and 2.38 MW, respectively.

  2. Calculation of eigenmodes in a nonperiodic corrugated waveguide

    SciTech Connect

    Tigelis, I.G. [Univ. of Athens (Greece)] [Univ. of Athens (Greece); Pedrozzi, M. [Ecole Polytechnique Federale de Lausanne (Switzerland). Centre de Researches en Physique des Plasmas] [Ecole Polytechnique Federale de Lausanne (Switzerland). Centre de Researches en Physique des Plasmas; Cottis, P.G.; Vomvoridis, J.L. [National Technical Univ. of Athens (Greece). Dept. of Electrical and Computer Engineering] [National Technical Univ. of Athens (Greece). Dept. of Electrical and Computer Engineering

    1997-02-01

    A theoretical technique for determining the dispersion relation, the electromagnetic field components, and the quality factor of a dielectric-loaded nonperiodic corrugated waveguide is presented for the case of azimuthally symmetric TM waves. The Floquet theorem is used to express the field distribution in the vacuum region, while an eigenfunction expansion is employed in each dielectric region, with the appropriate boundary conditions applied at the interfaces, leading to an infinite system of equations. This system is solved numerically by truncation, while the convergence of the solution is examined with the number of spatial harmonics. Based on this formulation, a numerical code, called FISHBONE-TM, is developed and its results are compared with those obtained with an established code (CASCADE) based on the scattering-matrix method.

  3. Modeling noncontact atomic force microscopy resolution on corrugated surfaces

    PubMed Central

    Burson, Kristen M; Yamamoto, Mahito

    2012-01-01

    Summary Key developments in NC-AFM have generally involved atomically flat crystalline surfaces. However, many surfaces of technological interest are not atomically flat. We discuss the experimental difficulties in obtaining high-resolution images of rough surfaces, with amorphous SiO2 as a specific case. We develop a quasi-1-D minimal model for noncontact atomic force microscopy, based on van der Waals interactions between a spherical tip and the surface, explicitly accounting for the corrugated substrate (modeled as a sinusoid). The model results show an attenuation of the topographic contours by ~30% for tip distances within 5 Å of the surface. Results also indicate a deviation from the Hamaker force law for a sphere interacting with a flat surface. PMID:22496996

  4. Hydrogen Piping Experience in Chevron

    E-print Network

    , 2" hydrogen piping failure) 4 #12;5 Hydrogen piping experience largely from hydroprocessing plantsHydrogen Piping Experience in Chevron Refining Ned Niccolls Materials Engineer Chevron Energy perspectives from long term use of hydrogen piping in refining. Piping specifications and practices. The (few

  5. Modular axial grooved heat pipes

    Microsoft Academic Search

    H. Koch; H. Kreeb; M. Perdu

    1976-01-01

    A modular axial grooved heat pipe system operable between 100 and 400 K was developed. Accent was placed on typical space application problems such as assembly of two heat pipes (interface problems), circular heat pipes, construction of radiators, long life behavior, and cryogenic heat pipes. Results of performance tests on this heat pipe system designed for a space radiator to

  6. Deployable Heat Pipe Radiator

    NASA Technical Reports Server (NTRS)

    Edelstein, F.

    1975-01-01

    A 1.2- by 1.8-m variable conductance heat pipe radiator was designed, built, and tested. The radiator has deployment capability and can passively control Freon-21 fluid loop temperatures under varying loads and environments. It consists of six grooved variable conductance heat pipes attached to a 0.032-in. aluminum panel. Heat is supplied to the radiator via a fluid header or a single-fluid flexible heat pipe header. The heat pipe header is an artery design that has a flexible section capable of bending up to 90 degrees. Radiator loads as high as 850 watts were successfully tested. Over a load variation of 200 watts, the outlet temperature of the Freon-21 fluid varied by 7 F. An alternate control system was also investigated which used a variable conductance heat pipe header attached to the heat pipe radiator panel.

  7. Miniature Heat Pipes

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Small Business Innovation Research contracts from Goddard Space Flight Center to Thermacore Inc. have fostered the company work on devices tagged "heat pipes" for space application. To control the extreme temperature ranges in space, heat pipes are important to spacecraft. The problem was to maintain an 8-watt central processing unit (CPU) at less than 90 C in a notebook computer using no power, with very little space available and without using forced convection. Thermacore's answer was in the design of a powder metal wick that transfers CPU heat from a tightly confined spot to an area near available air flow. The heat pipe technology permits a notebook computer to be operated in any position without loss of performance. Miniature heat pipe technology has successfully been applied, such as in Pentium Processor notebook computers. The company expects its heat pipes to accommodate desktop computers as well. Cellular phones, camcorders, and other hand-held electronics are forsible applications for heat pipes.

  8. Abrasion resistant heat pipe

    DOEpatents

    Ernst, D.M.

    1984-10-23

    A specially constructed heat pipe is described for use in fluidized bed combustors. Two distinct coatings are spray coated onto a heat pipe casing constructed of low thermal expansion metal, each coating serving a different purpose. The first coating forms aluminum oxide to prevent hydrogen permeation into the heat pipe casing, and the second coating contains stabilized zirconium oxide to provide abrasion resistance while not substantially affecting the heat transfer characteristics of the system.

  9. Abrasion resistant heat pipe

    DOEpatents

    Ernst, Donald M. (Leola, PA)

    1984-10-23

    A specially constructed heat pipe for use in fluidized bed combustors. Two distinct coatings are spray coated onto a heat pipe casing constructed of low thermal expansion metal, each coating serving a different purpose. The first coating forms aluminum oxide to prevent hydrogen permeation into the heat pipe casing, and the second coating contains stabilized zirconium oxide to provide abrasion resistance while not substantially affecting the heat transfer characteristics of the system.

  10. Development of a model for flaming combustion of double-wall corrugated cardboard

    NASA Astrophysics Data System (ADS)

    McKinnon, Mark B.

    Corrugated cardboard is used extensively in a storage capacity in warehouses and frequently acts as the primary fuel for accidental fires that begin in storage facilities. A one-dimensional numerical pyrolysis model for double-wall corrugated cardboard was developed using the Thermakin modeling environment to describe the burning rate of corrugated cardboard. The model parameters corresponding to the thermal properties of the corrugated cardboard layers were determined through analysis of data collected in cone calorimeter tests conducted with incident heat fluxes in the range 20--80 kW/m 2. An apparent pyrolysis reaction mechanism and thermodynamic properties for the material were obtained using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The fully-parameterized bench-scale model predicted burning rate profiles that were in agreement with the experimental data for the entire range of incident heat fluxes, with more consistent predictions at higher heat fluxes.

  11. Opportunities for Energy Efficiency and Demand Response in Corrugated Cardboard Manufacturing Facilities 

    E-print Network

    Chow, S.; Hackett, B.; Ganji, A. R.

    2005-01-01

    94132 Bryan Hackett BASE Energy, Inc.* San Francisco, CA 94103 Industrial Energy Technology Conference New Orleans, Louisiana May 11-12, 2005 ABSTRACT Corrugated cardboard manufacturing is an energy intensive process, in both electric...

  12. Flexural strengthening of Reinforced Concrete (RC) Beams Retrofitted with Corrugated Glass Fiber Reinforced Polymer (GFRP) Laminates

    NASA Astrophysics Data System (ADS)

    Aravind, N.; Samanta, Amiya K.; Roy, Dilip Kr. Singha; Thanikal, Joseph V.

    2015-01-01

    Strengthening the structural members of old buildings using advanced materials is a contemporary research in the field of repairs and rehabilitation. Many researchers used plain Glass Fiber Reinforced Polymer (GFRP) sheets for strengthening Reinforced Concrete (RC) beams. In this research work, rectangular corrugated GFRP laminates were used for strengthening RC beams to achieve higher flexural strength and load carrying capacity. Type and dimensions of corrugated profile were selected based on preliminary study using ANSYS software. A total of twenty one beams were tested to study the load carrying capacity of control specimens and beams strengthened with plain sheets and corrugated laminates using epoxy resin. This paper presents the experimental and theoretical study on flexural strengthening of Reinforced Concrete (RC) beams using corrugated GFRP laminates and the results are compared. Mathematical models were developed based on the experimental data and then the models were validated.

  13. Bending Tests of Circular Cylinders of Corrugated Aluminum-alloy Sheet

    NASA Technical Reports Server (NTRS)

    Buckwalter, John C; Reed, Warren D; Niles, Alfred S

    1937-01-01

    Bending tests were made of two circular cylinders of corrugated aluminum-alloy sheet. In each test failure occurred by bending of the corrugations in a plane normal to the skin. It was found, after analysis of the effect of short end bays, that the computed stress on the extreme fiber of a corrugated cylinder is in excess of that for a flat panel of the same basic pattern and panel length tested as a pin-ended column. It is concluded that this increased strength was due to the effects of curvature of the pitch line. It is also concluded from the tests that light bulkheads closely spaced strengthen corrugated cylinders very materially.

  14. Pipe crawler apparatus

    DOEpatents

    Hovis, Gregory L. (North Augusta, SC); Erickson, Scott A. (Augusta, GA); Blackmon, Bruce L. (Aiken, SC)

    2002-01-01

    A pipe crawler apparatus particularly useful for 3-inch and 4-inch diameter pipes is provided. The pipe crawler apparatus uses a gripping apparatus in which a free end of a piston rod is modified with a bearing retaining groove. Bearings, placed within the groove, are directed against a camming surface of three respective pivoting support members. The non-pivoting ends of the support members carry a foot-like gripping member that, upon pivoting of the support member, engages the interior wall of the pipe.

  15. Internal pipe attachment mechanism

    DOEpatents

    Bast, R.M.; Chesnut, D.A.; Henning, C.D.; Lennon, J.P.; Pastrnak, J.W.; Smith, J.A.

    1994-12-13

    An attachment mechanism is described for repairing or extending fluid carrying pipes, casings, conduits, etc. utilizing one-way motion of spring tempered fingers to provide a mechanical connection between the attachment mechanism and the pipe. The spring tempered fingers flex to permit insertion into a pipe to a desired insertion depth. The mechanical connection is accomplished by reversing the insertion motion and the mechanical leverage in the fingers forces them outwardly against the inner wall of the pipe. A seal is generated by crushing a sealing assembly by the action of setting the mechanical connection. 6 figures.

  16. External artery heat pipe

    NASA Technical Reports Server (NTRS)

    Gernert, Nelson J. (Inventor); Ernst, Donald M. (Inventor); Shaubach, Robert M. (Inventor)

    1989-01-01

    An improved heat pipe with an external artery. The longitudinal slot in the heat pipe wall which interconnects the heat pipe vapor space with the external artery is completely filled with sintered wick material and the wall of the external artery is also covered with sintered wick material. This added wick structure assures that the external artery will continue to feed liquid to the heat pipe evaporator even if a vapor bubble forms within and would otherwise block the liquid transport function of the external artery.

  17. Plasmons at the interface between a corrugated semiconductor film and a binary metallic superlattice

    NASA Astrophysics Data System (ADS)

    Jacobo-Escobar, J. H.; Saldaña, Xóchitl I.; Cocoletzi, Gregorio H.

    2000-08-01

    We investigate the minigaps of the dispersion relation of plasmon polaritons that propagate at the interface between a corrugated semiconductor film and a binary metallic superlattice. Minima of the reflectivity for p-polarized light are calculated and their frequencies are used to obtain the 'optical' dispersion relations which are compared with the corresponding electromagnetic dispersion curves, in the effective medium theory. Results show that the minigap enlarges with the corrugation strength.

  18. Application of Genetic Algorithms to the Shape Optimization of the Nonlinearly Elastic Corrugated Membranes

    Microsoft Academic Search

    Mikhail Karyakin; Taisiya Sigaeva

    \\u000a Corrugated membranes are extremely important structural parts of a great number of devices, highly sensitive pressure sensors\\u000a in particular. In engineering of corrugated shapes different factors could be taken into account as crucial. Among them –\\u000a membrane’s work without buckling, buckling for the prescribed load, flatness of the membrane characteristic – dependence of\\u000a the applied pressure on the liquid or

  19. A Ruthenium-Based Multimetal-Contact RF MEMS Switch With a Corrugated Diaphragm

    Microsoft Academic Search

    Feixiang Ke; Jianmin Miao; Joachim Oberhammer

    2008-01-01

    This paper presents a ruthenium metal-contact RF microelectromechanical system switch based on a corrugated silicon oxide\\/silicon nitride diaphragm. The corrugations are designed to substantially reduce the influence of the fabrication-induced stress in the membrane, resulting in a highly insensitive design to process parameter variations. Furthermore, a novel multilayer metal-contact concept, comprising a 50-nm chromium\\/50-nm ruthenium\\/500-nm gold\\/50-nm ruthenium structure, is introduced

  20. Impact of Atomic Corrugation on Sliding Friction as Probed by QCM

    Microsoft Academic Search

    Tonya Coffey; Sang Lee; Jacqueline Krim

    2004-01-01

    At the atomic scale, friction is believed to originate primarily via sliding induced excitation of phonons. [1] Theoretical predictions of the magnitude of phononic dissipation have been related to the atomic corrugation of the adsorbate\\/substrate potential. [2] Braun and colleagues [3] measured a corrugation of 1.9 meV for xenon on a copper(111) surface using helium atom scattering. Using the Quartz

  1. MICROSTRIP ANTENNA WITH CORRUGATED GROUND PLANE SURFACE AS A SENSOR FOR LANDMINES DETECTION

    Microsoft Academic Search

    Saber Helmy Zainud-Deen; Mosad El. Sayed Badr; Emad El-Deen; Kamal Hassan Awadalla

    2008-01-01

    Abstract—A proposed sensor for landmines detection consists of two parallel microstrip antennas placed on the same ground plane and with corrugated ground surface between the arrays has been investigated. The microstrip patch array with corrugated ground surface has the advantage of a low mutual coupling compared with the classic arrays. The Finite-Difference Time-Domain (FDTD) is used to simulate the sensor

  2. Sequence identification of Mogollon-Mimbres corrugated wares from the NAN Ruin, Grant County, New Mexico 

    E-print Network

    McCollum, Teresa Ann

    1992-01-01

    APPENDIX VI. PITCHERS ENUMERATED BY TYPE, PROVENIENCE, AND PHASE. . APPENDIX VII ' MEASUREMENTS FOR WHOLE/RECONSTRUCTED VESSELS. . . PAGE 189 190 VITA 192 LIST OF TABLES TABLE 1 Seriation of Georgetown and San Francisco Phase corrugated wares... variability and identify changes in wares from the San Francisco Phase through the Classic Mimbres Phase (A. D. 650-A. D. 1150) (Shafer 1988). The typology will then be used to seriate the corrugated wares and develop a cultural sequence based...

  3. Numerical and Experimental Investigations on Mechanical Behavior of Composite Corrugated Core

    NASA Astrophysics Data System (ADS)

    Dayyani, Iman; Ziaei-Rad, Saeed; Salehi, Hamid

    2012-06-01

    Tensile and flexural characteristics of corrugated laminate panels were studied using numerical and analytical methods and compared with experimental data. Prepreg laminates of glass fiber plain woven cloth were hand-laid by use of a heat gun to ease the creation of the panel. The corrugated panels were then manufactured by using a trapezoidal machined aluminium mould. First, a series of simple tension tests were performed on standard samples to evaluate the material characteristics. Next, the corrugated panels were subjected to tensile and three-point bending tests. The force-displacement graphs were recorded. Numerical and analytical solutions were proposed to simulate the mechanical behavior of the panels. In order to model the energy dissipation due to delamination phenomenon observed in tensile tests in all members of corrugated core, plastic behavior was assigned to the whole geometry, not only to the corner regions. Contrary to the literature, it is shown that the three-stage mechanical behavior of composite corrugated core is not confined to aramid reinforced corrugated laminates and can be observed in other types such as fiber glass. The results reveal that the mechanical behavior of the core in tension is sensitive to the variation of core height. In addition, for the first time, the behavior of composite corrugated core was studied and verified in bending. Finally, the analytical and numerical results were validated by comparing them with experimental data. A good degree of correlation was observed which showed the suitability of the finite element model for predicting the mechanical behavior of corrugated laminate panels.

  4. Jamaican red clay tobacco pipes 

    E-print Network

    Heidtke, Kenan Paul

    1992-01-01

    -made earthenware tobacco pipes has only been undertaken in the last few years. These red clay pipes occur at several colonial sites in North America, the Caribbean, and South America. This thesis will be a detailed study of the red clay pipes found in Jamaica... used on the pipes, and to offer possible explanations for the markings and stylistic attributes of the pipes. Locally made earthenware pipes from other colonial sites in the New World will also be examined to identify possible parallels...

  5. Heat pipe technology issues

    SciTech Connect

    Merrigan, M.A.

    1984-04-01

    Critical high temperature, high power applications in space nuclear power designs are near the current state of the art of heat pipe technology in terms of power density, operating temperature, and lifetime. Recent heat pipe development work at Los Alamos National Laboratory has involved performance testing of typical space reactor heat pipe designs to power levels in excess of 19 kW/cm/sup 2/ axially and 300 W/cm/sup 2/ radially at temperatures in the 1400 to 1500 K range. Operation at conditions in the 10 kW/cm/sup 2/ range has been sustained for periods of up to 1000 hours without evidence of performance degradation. The effective length for heat transport in these heat pipes was from 1.0 to 1.5 M. Materials used were molybdenum alloys with lithium employed as the heat pipe operating fluid. Shorter, somewhat lower power, molybdenum heat pipes have been life tested at Los Alamos for periods of greater than 25,000 hours at 1700 K with lithium and 20,000 hours at 1500/sup 0/K with sodium. These life test demonstrations and the attendant performance limit investigations provide an experimental basis for heat pipe application in space reactor design and represent the current state-of-the-art of high temperature heat pipe technology.

  6. Loop heat pipes

    Microsoft Academic Search

    Yu. F. Maydanik

    2005-01-01

    Loop heat pipes (LHPs) are two-phase heat-transfer devices with capillary pumping of a working fluid. They possess all the main advantages of conventional heat pipes, but owing to the original design and special properties of the capillary structure are capable of transferring heat efficiency for distances up to several meters at any orientation in the gravity field, or to several

  7. Heat pipe development status

    SciTech Connect

    Merrigan, M.A.

    1984-01-01

    Test heat pipes have been operated in the 1400 K to 1700 K range for periods in excess of 20,000 hours with the objective of understanding and controlling corrosion and failure mechanisms. The results of a post test analysis of one of these heat pipes that was operated for 25,216 hours at 1700 K are reviewed and the implications for heat pipe lifetime discussed. An in-process report of an investigation of transient heat pipe behavior is presented. This investigation is being conducted as a result of restart problems encountered during life test of a 2 m. radiation cooled heat pipe. The results of a series of shut-down tests from power and temperature are given and probable causes of the restart problem discussed.

  8. Corrugator activity confirms immediate negative affect in surprise.

    PubMed

    Topolinski, Sascha; Strack, Fritz

    2015-01-01

    The emotion of surprise entails a complex of immediate responses, such as cognitive interruption, attention allocation to, and more systematic processing of the surprising stimulus. All these processes serve the ultimate function to increase processing depth and thus cognitively master the surprising stimulus. The present account introduces phasic negative affect as the underlying mechanism responsible for this switch in operating mode. Surprising stimuli are schema-discrepant and thus entail cognitive disfluency, which elicits immediate negative affect. This affect in turn works like a phasic cognitive tuning switching the current processing mode from more automatic and heuristic to more systematic and reflective processing. Directly testing the initial elicitation of negative affect by surprising events, the present experiment presented high and low surprising neutral trivia statements to N = 28 participants while assessing their spontaneous facial expressions via facial electromyography. High compared to low surprising trivia elicited higher corrugator activity, indicative of negative affect and mental effort, while leaving zygomaticus (positive affect) and frontalis (cultural surprise expression) activity unaffected. Future research shall investigate the mediating role of negative affect in eliciting surprise-related outcomes. PMID:25762956

  9. Dispersionless Manipulation of Reflected Acoustic Wavefront by Subwavelength Corrugated Surface

    PubMed Central

    Zhu, Yi-Fan; Zou, Xin-Ye; Li, Rui-Qi; Jiang, Xue; Tu, Juan; Liang, Bin; Cheng, Jian-Chun

    2015-01-01

    Free controls of optic/acoustic waves for bending, focusing or steering the energy of wavefronts are highly desirable in many practical scenarios. However, the dispersive nature of the existing metamaterials/metasurfaces for wavefront manipulation necessarily results in limited bandwidth. Here, we propose the concept of dispersionless wavefront manipulation and report a theoretical, numerical and experimental work on the design of a reflective surface capable of controlling the acoustic wavefront arbitrarily without bandwidth limitation. Analytical analysis predicts the possibility to completely eliminate the frequency dependence with a specific gradient surface which can be implemented by designing a subwavelength corrugated surface. Experimental and numerical results, well consistent with the theoretical predictions, have validated the proposed scheme by demonstrating a distinct phenomenon of extraordinary acoustic reflection within an ultra-broad band. For acquiring a deeper insight into the underlying physics, a simple physical model is developed which helps to interpret this extraordinary phenomenon and predict the upper cutoff frequency precisely. Generations of planar focusing and non-diffractive beam have also been exemplified. With the dispersionless wave-steering capability and deep discrete resolution, our designed structure may open new avenue to fully steer classical waves and offer design possibilities for broadband optical/acoustical devices. PMID:26077772

  10. The corrugation instability of a piston-driven shock wave

    NASA Astrophysics Data System (ADS)

    Bates, Jason

    2014-10-01

    We investigate the dynamics of a shock wave that is driven into an inviscid fluid by the steady motion of a two-dimensional planar piston with small corrugations on its surface. This problem was first considered by Freeman [Proc. Royal Soc. A. 228, 341 (1955)], who showed that piston-driven shocks are unconditionally stable when the medium through which they propagate is an ideal gas. Here, we generalize his work to account for a fluid with an arbitrary equation of state. We find that shocks are stable when - 1 < h

  11. Dispersionless Manipulation of Reflected Acoustic Wavefront by Subwavelength Corrugated Surface.

    PubMed

    Zhu, Yi-Fan; Zou, Xin-Ye; Li, Rui-Qi; Jiang, Xue; Tu, Juan; Liang, Bin; Cheng, Jian-Chun

    2015-01-01

    Free controls of optic/acoustic waves for bending, focusing or steering the energy of wavefronts are highly desirable in many practical scenarios. However, the dispersive nature of the existing metamaterials/metasurfaces for wavefront manipulation necessarily results in limited bandwidth. Here, we propose the concept of dispersionless wavefront manipulation and report a theoretical, numerical and experimental work on the design of a reflective surface capable of controlling the acoustic wavefront arbitrarily without bandwidth limitation. Analytical analysis predicts the possibility to completely eliminate the frequency dependence with a specific gradient surface which can be implemented by designing a subwavelength corrugated surface. Experimental and numerical results, well consistent with the theoretical predictions, have validated the proposed scheme by demonstrating a distinct phenomenon of extraordinary acoustic reflection within an ultra-broad band. For acquiring a deeper insight into the underlying physics, a simple physical model is developed which helps to interpret this extraordinary phenomenon and predict the upper cutoff frequency precisely. Generations of planar focusing and non-diffractive beam have also been exemplified. With the dispersionless wave-steering capability and deep discrete resolution, our designed structure may open new avenue to fully steer classical waves and offer design possibilities for broadband optical/acoustical devices. PMID:26077772

  12. Order–disorder transition for corrugated Au layers

    SciTech Connect

    Fukutani, Keisuke; Lozova, N.; Zuber, S. M.; Dowben, P. A.; Galiy, P.; Losovyl, Yaroslav B.

    2010-01-01

    Atomic-scale structure of the growth of a gold film on (1 1 2) plane of Mo single crystal was investigated by means of low energy electron diffraction (LEED) and scanning tunneling microscopy (STM) up to two monolayers (ML) of gold coverage. Both LEED and STM results establish that Au grows on Mo(1 1 2) in a layer-by-layer mode, for at least the first two monolayers. A number of ordered structures are formed and both the first and second layers adopt the Mo(1 1 2) 1 × 1 surface structure upon completion. For some gold layers on Mo(1 1 2), notably the 1.66 monolayer 3 × 1 and 1.75 monolayer 4 × 1 gold overlayers, we find evidence of a phase transition associated with increasing disorder in gold layers with structural corrugation and anisotropic band structure. The signature of this phase transition, at temperatures in the range of 400–500 K, is a sharp decrease in the overlayer effective Debye temperature.

  13. Driving corrugated donut rotors with Laguerre-Gauss beams.

    PubMed

    Loke, Vincent L Y; Asavei, Theodor; Stilgoe, Alexander B; Nieminen, Timo A; Rubinsztein-Dunlop, Halina

    2014-08-11

    Tightly-focused laser beams that carry angular momentum have been used to trap and rotate microrotors. In particular, a Laguerre-Gauss mode laser beam can be used to transfer its orbital angular momentum to drive microrotors. We increase the torque efficiency by a factor of about 2 by designing the rotor such that its geometry is compatible with the driving beam, when driving the rotation with the optimum beam, rather than beams of higher or lower orbital angular momentum. Based on Floquet's theorem, the order of discrete rotational symmetry of the rotor can be made to couple with the azimuthal mode of the Laguerre-Gauss beam. We design corrugated donut rotors, that have a flat disc-like profile, with the help of the discrete dipole approximation and the T-matrix methods in parallel with experimental demonstrations of stable trapping and torque measurement. We produce and test such a rotor using two-photon photopolymerization. With a rotor that has 8-fold discrete rotational symmetry, an outer radius of 1.85 ?m and a hollow core radius of 0.5 ?m, we were able to transfer approximately 0.3 h? per photon of the orbital angular momentum from an LG04 beam. PMID:25321053

  14. Stiffness analysis of corrugated flexure beam used in compliant mechanisms

    NASA Astrophysics Data System (ADS)

    Wang, Nianfeng; Liang, Xiaohe; Zhang, Xianmin

    2015-05-01

    Conventional flexible joints generally have limited range of motion and high stress concentration. To overcome these shortcomings, corrugated flexure beam(CF beam) is designed because of its large flexibility obtained from longer overall length on the same span. The successful design of compliant mechanisms using CF beam requires manipulation of the stiffnesses as the design variables. Empirical equations of the CF beam stiffness components, except of the torsional stiffness, are obtained by curve-fitting method. The application ranges of all the parameters in each empirical equation are also discussed. The ratio of off-axis to axial stiffness is considered as a key characteristic of an effective compliant joint. And parameter study shows that the radius of semi-circular segment and the length of straight segment contribute most to the ratio. At last, CF beam is used to design translational and rotational flexible joints, which also verifies the validity of the empirical equations. CF beam with large flexibility is presented, and empirical equations of its stiffness are proposed to facilitate the design of flexible joint with large range of motion.

  15. Automated Ultrasonic Pipe Weld Inspection

    Microsoft Academic Search

    Wolfram A. Karl; Peter SCHULTE; Michael JOSWIG; Rainer KATTWINKEL

    Summary This article contains an overview on automated ultrasonic w eld inspection for various pipe types. Some inspection steps might by carried out with portable t est equipment (e.g. pipe end test), but the weld inspection in all internationally relevant specif ications must be automated. The pipe geometry, the production process, and the further pipe usage determine if ND T

  16. Flexible ultrasonic pipe inspection apparatus

    DOEpatents

    Jenkins, C.F.; Howard, B.D.

    1994-01-01

    Pipe crawlers, pipe inspection {open_quotes}rabbits{close_quotes} and similar vehicles are widely used for inspecting the interior surfaces of piping systems, storage tanks and process vessels for damaged or flawed structural features. This paper describes the design of a flexible, modular ultrasonic pipe inspection apparatus.

  17. Gas pipe explorer robot

    NASA Technical Reports Server (NTRS)

    Wilcox, Brian (Inventor)

    2004-01-01

    A gas pipe explorer formed of a plurality of connecting elements, and an articulation element between the connected elements. The connected elements include drive capabilities, and the articulation element allows the connected elements to traverse gas pipes of arbitrary shapes and sizes. A sensor may sends the characteristics of the gas pipe, and the communication element may send back those sends characteristics. The communication can be wired, over a tether connecting the device to a remote end. Alternatively, the connection can be wireless, driven by either a generator or a battery.

  18. Improved Thin, Flexible Heat Pipes

    NASA Technical Reports Server (NTRS)

    Rosenfeld, John H.; Gernert, Nelson J.; Sarraf, David B.; Wollen, Peter J.; Surina, Frank C.; Fale, John E.

    2004-01-01

    Flexible heat pipes of an improved type are fabricated as layers of different materials laminated together into vacuum- tight sheets or tapes. In comparison with prior flexible heat pipes, these flexible heat pipes are less susceptible to leakage. Other advantages of these flexible heat pipes, relative to prior flexible heat pipes, include high reliability and greater ease and lower cost of fabrication. Because these heat pipes are very thin, they are highly flexible. When coated on outside surfaces with adhesives, these flexible heat pipes can be applied, like common adhesive tapes, to the surfaces of heat sinks and objects to be cooled, even if those surfaces are curved.

  19. Probe the Corrugation and Friction of Cu(111) toward Ne and Xe: First Principles Studies

    NASA Astrophysics Data System (ADS)

    Zhang, Yanning; Bortolani, Virginio; Wu, Ruqian

    2014-03-01

    The interaction between rare-gas (RG) and metal surface is typically described as the sum of two contributions: van der Waals attraction at large RG-metal distances, and Pauli repulsion at short distances. In the repulsive range, RG atoms can see a corrugated or anticorrugated potential surface, depending on the change of charge density profile of the surface atoms. The probe of the corrugation effects near the attractive part is also important since the corrugated or anticorrugated charge distribution at the surface can significantly change the physical properties of the whole system. In this letter, we show that also near the negative potential well of Ne and Xe monolayers on Cu(111), we can observe different surface corrugations: while the potential surface of Ne on Cu(111) is corrugated, it is anticorrugated for Xe/Cu(111). The analyses of electronic properties reveal that the weak hybridization of RG p- and substrate d-states is critical for the surface anticorrugation. Studies of the activation energies along sliding paths imply that Ne motion is much faster than Xe on Cu(111). Density functional calculations with self-consistent nonlocal van der Waals functional were used throughout our studies. The work was supported by DOE-BES (Grant No. DE- FG02-05ER46237) and by NERSC for computing time.

  20. Electrohydrodynamic heat pipe experiments

    NASA Technical Reports Server (NTRS)

    Jones, T. B.; Perry, M. P.

    1974-01-01

    Experiments with two electrohydrodynamic heat pipes are reported. Both devices employ an electromechanical flow structure for axial liquid flow and a capillary wicking structure for (1) collection of condensed liquid at the cooled end and (2) distribution of this liquid at the heated end. One device has circumferential grooving for the capillary structure and the other has feltmetal wicking. The experiments successfully demonstrate the electrohydrodynamic heat pipe concept. Compatibility of the two circumferential wick structures with an axial electromechanical flow structure is also demonstrated. A significant mismatch of the capillary groove and electrohydrodynamic pumping capabilities results in severe hydrodynamic burn-out limiting in the first heat pipe. Both devices have very poor over-all thermal conductances of the order of 1-2 W/deg C, reflecting the generally poor heat-transfer properties of the dielectric working fluids required in electrohydrodynamic heat pipes.

  1. Miniature pipe crawler tractor

    SciTech Connect

    McKay, M.D.; Anderson, M.O.; Ferrante, T.A.; Willis, W.D.

    2000-03-14

    A pipe crawler tractor may comprise a half tractor assembly having a first base drive wheel, a second base drive wheel, and a top drive wheel. The drive wheels are mounted in spaced-apart relation so that the top drive wheel is positioned between the first and second base drive wheels. The mounting arrangement is also such that the first and second base drive wheels contact the inside surface of the pipe at respective first and second positions and so that the top drive wheel contacts the inside surface of the pipe at a third position, the third position being substantially diametrically opposed to the first and second positions. A control system connected to the half tractor assembly controls the rotation of the first base wheel, the second base wheel, and the top drive wheel to move the half tractor assembly within the pipe.

  2. Heat Pipe Systems

    NASA Technical Reports Server (NTRS)

    1993-01-01

    The heat pipe was developed to alternately cool and heat without using energy or any moving parts. It enables non-rotating spacecraft to maintain a constant temperature when the surface exposed to the Sun is excessively hot and the non Sun-facing side is very cold. Several organizations, such as Tropic-Kool Engineering Corporation, joined NASA in a subsequent program to refine and commercialize the technology. Heat pipes have been installed in fast food restaurants in areas where humid conditions cause materials to deteriorate quickly. Moisture removal was increased by 30 percent in a Clearwater, FL Burger King after heat pipes were installed. Relative humidity and power consumption were also reduced significantly. Similar results were recorded by Taco Bell, which now specifies heat pipe systems in new restaurants in the Southeast.

  3. Freezable heat pipe

    DOEpatents

    Ernst, Donald M. (Leola, PA); Sanzi, James L. (Lancaster, PA)

    1981-02-03

    A heat pipe whose fluid can be repeatedly frozen and thawed without damage to the casing. An additional part is added to a conventional heat pipe. This addition is a simple porous structure, such as a cylinder, self-supporting and free standing, which is dimensioned with its diameter not spanning the inside transverse dimension of the casing, and with its length surpassing the depth of maximum liquid.

  4. Silicon Heat Pipe Array

    NASA Technical Reports Server (NTRS)

    Yee, Karl Y.; Ganapathi, Gani B.; Sunada, Eric T.; Bae, Youngsam; Miller, Jennifer R.; Beinsford, Daniel F.

    2013-01-01

    Improved methods of heat dissipation are required for modern, high-power density electronic systems. As increased functionality is progressively compacted into decreasing volumes, this need will be exacerbated. High-performance chip power is predicted to increase monotonically and rapidly with time. Systems utilizing these chips are currently reliant upon decades of old cooling technology. Heat pipes offer a solution to this problem. Heat pipes are passive, self-contained, two-phase heat dissipation devices. Heat conducted into the device through a wick structure converts the working fluid into a vapor, which then releases the heat via condensation after being transported away from the heat source. Heat pipes have high thermal conductivities, are inexpensive, and have been utilized in previous space missions. However, the cylindrical geometry of commercial heat pipes is a poor fit to the planar geometries of microelectronic assemblies, the copper that commercial heat pipes are typically constructed of is a poor CTE (coefficient of thermal expansion) match to the semiconductor die utilized in these assemblies, and the functionality and reliability of heat pipes in general is strongly dependent on the orientation of the assembly with respect to the gravity vector. What is needed is a planar, semiconductor-based heat pipe array that can be used for cooling of generic MCM (multichip module) assemblies that can also function in all orientations. Such a structure would not only have applications in the cooling of space electronics, but would have commercial applications as well (e.g. cooling of microprocessors and high-power laser diodes). This technology is an improvement over existing heat pipe designs due to the finer porosity of the wick, which enhances capillary pumping pressure, resulting in greater effective thermal conductivity and performance in any orientation with respect to the gravity vector. In addition, it is constructed of silicon, and thus is better suited for the cooling of semiconductor devices.

  5. Improvement of light extraction in organic light-emitting diodes using a corrugated microcavity.

    PubMed

    Jiao, Bo; Yu, Yue; Dai, Yang; Hou, Xun; Wu, Zhaoxin

    2015-02-23

    Based on the phase separation effect in the film formation process of Polystyrene and Poly(methyl methacrylate) blend solution, bottom-emitting organic light-emitting diodes (OLEDs) with corrugated microcavity was demonstrated. This device exhibited high efficiency, broad spectra and Lambertian angular emission. Compared with the traditional bottom-emitting OLEDs with ITO anode and the planar microcavity OLEDs, about 57% and 41% enhancement for external quantum efficiency was achieved in this corrugated microcavity OLEDs respectively. This improvement can be understood by the scattering effect of the quasi-periodic characteristic of this corrugated microcavity which reduces the optical loss at surface plasmon polariton modes and wave-guided modes. This work provides a simple as well as efficienct method to recover trapped light in OLEDs, which will benefit the low cost fabrication process. PMID:25836444

  6. Demonstration of nonlinear-energy-spread compensation in relativistic electron bunches with corrugated structures

    E-print Network

    Fu, Feichao; Zhu, Pengfei; Zhao, Lingrong; Jiang, Tao; Lu, Chao; Liu, Shengguang; Shi, Libin; Yan, Lixin; Deng, Haixiao; Feng, Chao; Gu, Qiang; Huang, Dazhang; Liu, Bo; Wang, Dong; Wang, Xingtao; Zhang, Meng; Zhao, Zhentang; Stupakov, Gennady; Xiang, Dao; Zhang, Jie

    2015-01-01

    High quality electron beams with flat distributions in both energy and current are critical for many accelerator-based scientific facilities such as free-electron lasers and MeV ultrafast electron diffraction and microscopes. In this Letter we report on using corrugated structures to compensate for the beam nonlinear energy chirp imprinted by the curvature of the radio-frequency field, leading to a significant reduction in beam energy spread. By using a pair of corrugated structures with orthogonal orientations, we show that the quadrupole wake fields which otherwise increase beam emittance can be effectively canceled. This work also extends the applications of corrugated structures to the low beam charge (a few pC) and low beam energy (a few MeV) regime and may have a strong impact in many accelerator-based facilities.

  7. Demonstration of nonlinear-energy-spread compensation in relativistic electron bunches with corrugated structures.

    PubMed

    Fu, Feichao; Wang, Rui; Zhu, Pengfei; Zhao, Lingrong; Jiang, Tao; Lu, Chao; Liu, Shengguang; Shi, Libin; Yan, Lixin; Deng, Haixiao; Feng, Chao; Gu, Qiang; Huang, Dazhang; Liu, Bo; Wang, Dong; Wang, Xingtao; Zhang, Meng; Zhao, Zhentang; Stupakov, Gennady; Xiang, Dao; Zhang, Jie

    2015-03-20

    High quality electron beams with flat distributions in both energy and current are critical for many accelerator-based scientific facilities such as free-electron lasers and MeV ultrafast electron diffraction and microscopes. In this Letter, we report on using corrugated structures to compensate for the beam nonlinear energy chirp imprinted by the curvature of the radio-frequency field, leading to a significant reduction in beam energy spread. By using a pair of corrugated structures with orthogonal orientations, we show that the quadrupole wakefields, which, otherwise, increase beam emittance, can be effectively canceled. This work also extends the applications of corrugated structures to the low beam charge (a few pC) and low beam energy (a few MeV) regime and may have a strong impact in many accelerator-based facilities. PMID:25839281

  8. Demonstration of Nonlinear-Energy-Spread Compensation in Relativistic Electron Bunches with Corrugated Structures

    NASA Astrophysics Data System (ADS)

    Fu, Feichao; Wang, Rui; Zhu, Pengfei; Zhao, Lingrong; Jiang, Tao; Lu, Chao; Liu, Shengguang; Shi, Libin; Yan, Lixin; Deng, Haixiao; Feng, Chao; Gu, Qiang; Huang, Dazhang; Liu, Bo; Wang, Dong; Wang, Xingtao; Zhang, Meng; Zhao, Zhentang; Stupakov, Gennady; Xiang, Dao; Zhang, Jie

    2015-03-01

    High quality electron beams with flat distributions in both energy and current are critical for many accelerator-based scientific facilities such as free-electron lasers and MeV ultrafast electron diffraction and microscopes. In this Letter, we report on using corrugated structures to compensate for the beam nonlinear energy chirp imprinted by the curvature of the radio-frequency field, leading to a significant reduction in beam energy spread. By using a pair of corrugated structures with orthogonal orientations, we show that the quadrupole wakefields, which, otherwise, increase beam emittance, can be effectively canceled. This work also extends the applications of corrugated structures to the low beam charge (a few pC) and low beam energy (a few MeV) regime and may have a strong impact in many accelerator-based facilities.

  9. Measurement and correlation of aerodynamic heating to surface corrugation stiffened structures in thick turbulent boundary layers

    NASA Technical Reports Server (NTRS)

    Brandon, H. J.; Masek, R. V.

    1974-01-01

    The flow conditions for which heating distributions were measured on corrugated surfaces and wavy walls in turbulent boundary layers are shown, along with the ratio of the displacement thickness to the roughness height versus the local edge Mach number for an equivalent smooth surface. The present data are seen to greatly extend the range of data available on corrugated surfaces in turbulent boundary layers. These data were obtained by testing fullscale corrugation roughened panels in the wall boundary layer of a supersonic and hypersonic wind tunnel. The experimental program used to obtain the data is described. The data are analyzed and correlated in terms of the pertinent flow and geometric parameters. The developed correlations are compared with the available thin boundary layer data, as well as with previously published correlation techniques.

  10. Graphene on Ru(0001) Moire Corrugation Studied by Scanning Tunneling Microscopy on Au/Graphene/Ru(0001) Heterostructures

    E-print Network

    Ciobanu, Cristian

    Graphene on Ru(0001) Moire Corrugation Studied by Scanning Tunneling Microscopy on Au/Graphene on graphene/Ru(0001) were used to study the corrugation of the moire structure of graphene/Ru(0001 for the graphene/Ru(0001) moire is of structural nature rather than electronic. STM showed a large value

  11. Heat Transfer Coefficient and Friction Factor Prediction of Corrugated Tubes Combined With Twisted Tape Inserts Using Artificial Neural Network

    Microsoft Academic Search

    Mohammad Reza Jafari Nasr; Ali Habibi Khalaj

    2010-01-01

    In the research described here, artificial neural network (ANN) approach has been utilized to characterize the thermohydraulic behavior of corrugated tubes combined with twisted tape inserts in a turbulent flow regime. The experimental data sets were extracted from 57 tubes, 9 and 3 spirally corrugated tubes with varying geometries combined with 5 and 4 twisted tapes with different pitches. The

  12. Spatial Stereoresolution for Depth Corrugations May Be Set in Primary Visual Cortex

    PubMed Central

    Allenmark, Fredrik; Read, Jenny C. A.

    2011-01-01

    Stereo “3D” depth perception requires the visual system to extract binocular disparities between the two eyes' images. Several current models of this process, based on the known physiology of primary visual cortex (V1), do this by computing a piecewise-frontoparallel local cross-correlation between the left and right eye's images. The size of the “window” within which detectors examine the local cross-correlation corresponds to the receptive field size of V1 neurons. This basic model has successfully captured many aspects of human depth perception. In particular, it accounts for the low human stereoresolution for sinusoidal depth corrugations, suggesting that the limit on stereoresolution may be set in primary visual cortex. An important feature of the model, reflecting a key property of V1 neurons, is that the initial disparity encoding is performed by detectors tuned to locally uniform patches of disparity. Such detectors respond better to square-wave depth corrugations, since these are locally flat, than to sinusoidal corrugations which are slanted almost everywhere. Consequently, for any given window size, current models predict better performance for square-wave disparity corrugations than for sine-wave corrugations at high amplitudes. We have recently shown that this prediction is not borne out: humans perform no better with square-wave than with sine-wave corrugations, even at high amplitudes. The failure of this prediction raised the question of whether stereoresolution may actually be set at later stages of cortical processing, perhaps involving neurons tuned to disparity slant or curvature. Here we extend the local cross-correlation model to include existing physiological and psychophysical evidence indicating that larger disparities are detected by neurons with larger receptive fields (a size/disparity correlation). We show that this simple modification succeeds in reconciling the model with human results, confirming that stereoresolution for disparity gratings may indeed be limited by the size of receptive fields in primary visual cortex. PMID:21876667

  13. Structural efficiency studies of corrugated compression panels with curved caps and beaded webs

    NASA Technical Reports Server (NTRS)

    Davis, R. C.; Mills, C. T.; Prabhakaran, R.; Jackson, L. R.

    1984-01-01

    Curved cross-sectional elements are employed in structural concepts for minimum-mass compression panels. Corrugated panel concepts with curved caps and beaded webs are optimized by using a nonlinear mathematical programming procedure and a rigorous buckling analysis. These panel geometries are shown to have superior structural efficiencies compared with known concepts published in the literature. Fabrication of these efficient corrugation concepts became possible by advances made in the art of superplastically forming of metals. Results of the mass optimization studies of the concepts are presented as structural efficiency charts for axial compression.

  14. Demonstration of the asymmetric lateral Casimir force between corrugated surfaces in the nonadditive regime

    E-print Network

    H. -C. Chiu; G. L. Klimchitskaya; V. N. Marachevsky; V. M. Mostepanenko; U. Mohideen

    2009-09-11

    The measurement of the lateral Casimir force between two aligned sinusoidally corrugated Au-coated surfaces has been performed in the nonadditive regime. The use of deeper corrugations also allowed to demonstrate an asymmetry in the phase dependences of the lateral Casimir force, as predicted earlier. The measurement data are found to be in excellent agreement with the exact theoretical results computed at T=300 K including effect of real material properties. The deviations between the exact theory and the proximity force approximation are quantified. The obtained results are topical for applications in nanomachines.

  15. Elastic constants for superplastically formed/diffusion-bonded corrugated sandwich core

    NASA Technical Reports Server (NTRS)

    Ko, W. L.

    1980-01-01

    Formulas and associated graphs for evaluating the effective elastic constants for a superplastically formed/diffusion bonded (SPF/DB) corrugated sandwich core, are presented. A comparison of structural stiffnesses of the sandwich core and a honeycomb core under conditions of equal sandwich core density was made. The stiffness in the thickness direction of the optimum SPF/DB corrugated core (that is, triangular truss core) is lower than that of the honeycomb core, and that the former has higher transverse shear stiffness than the latter.

  16. Tests of Large Airfoils in the Propeller Research Tunnel, Including Two with Corrugated Surfaces

    NASA Technical Reports Server (NTRS)

    Wood, Donald H

    1930-01-01

    This report gives the results of the tests of seven 2 by 12 foot airfoils (Clark Y, smooth and corrugated, Gottingen 398, N.A.C.A. M-6, and N.A.C.A. 84). The tests were made in the propeller research tunnel of the National Advisory Committee for Aeronautics at Reynolds numbers up to 2,000,000. The Clark Y airfoil was tested with three degrees of surface smoothness. Corrugating the surface causes a flattening of the lift curve at the burble point and an increase in drag at small flying angles.

  17. Shear band blocking in explosively driven collapse of corrugated Ni-Al laminate cylinder

    NASA Astrophysics Data System (ADS)

    Olney, Karl; Chiu, Po-Hsun; Higgins, Andrew; Serge, Matthew; Fritz, Gregory; Stover, Adam; Nesterenko, Vitali; Benson, David

    2013-03-01

    Ni-Al laminate materials have been identified as a possible material system that can be used as a reactive material due to the self-sustaining reaction between Al and Ni layers. Besides traditional ignition methods, shear bands developed during mechanical loading can provide sites where ignition can occur. Corrugated Ni-Al laminate samples were created by swaging alternating layers of Ni (20 micrometers thick) and Al (30 micrometers thick) foils. The thick-walled cylinder (TWC) technique was performed on a corrugated Ni-Al laminate cylinder sample to examine shear band development in this material. Post experiment examination of the corrugated Ni-Al laminate material showed that the development of global shear bands were blocked via mesoscale mechanisms. The collapse of the corrugated laminate cylinder was simulated providing insight into these mesoscale mechanisms that were involved in blocking the development of shear bands during the experiment. Despite the shear band resistance of the material, several regions of the sample had localized reactions of Al and Ni spanning approximately 10-20 layers of laminate. Ni-Al laminate materials have been identified as a possible material system that can be used as a reactive material due to the self-sustaining reaction between Al and Ni layers. Besides traditional ignition methods, shear bands developed during mechanical loading can provide sites where ignition can occur. Corrugated Ni-Al laminate samples were created by swaging alternating layers of Ni (20 micrometers thick) and Al (30 micrometers thick) foils. The thick-walled cylinder (TWC) technique was performed on a corrugated Ni-Al laminate cylinder sample to examine shear band development in this material. Post experiment examination of the corrugated Ni-Al laminate material showed that the development of global shear bands were blocked via mesoscale mechanisms. The collapse of the corrugated laminate cylinder was simulated providing insight into these mesoscale mechanisms that were involved in blocking the development of shear bands during the experiment. Despite the shear band resistance of the material, several regions of the sample had localized reactions of Al and Ni spanning approximately 10-20 layers of laminate. Funding was provided by ONR MURI N00014-07-1-0740 (Program Officer Dr. Clifford Bedford)

  18. Heat pipes and use of heat pipes in furnace exhaust

    DOEpatents

    Polcyn, Adam D. (Pittsburgh, PA)

    2010-12-28

    An array of a plurality of heat pipe are mounted in spaced relationship to one another with the hot end of the heat pipes in a heated environment, e.g. the exhaust flue of a furnace, and the cold end outside the furnace. Heat conversion equipment is connected to the cold end of the heat pipes.

  19. Apparatus for moving a pipe inspection probe through piping

    DOEpatents

    Zollinger, W.T.; Appel, D.K.; Lewis, G.W.

    1995-07-18

    A method and apparatus are disclosed for controllably moving devices for cleaning or inspection through piping systems, including piping systems with numerous piping bends therein, by using hydrostatic pressure of a working fluid introduced into the piping system. The apparatus comprises a reservoir or other source for supplying the working fluid to the piping system, a launch tube for admitting the device into the launcher and a reversible, positive displacement pump for controlling the direction and flow rate of the working fluid. The device introduced into the piping system moves with the flow of the working fluid through the piping system. The launcher attaches to the valved ends of a piping system so that fluids in the piping system can recirculate in a closed loop. The method comprises attaching the launcher to the piping system, supplying the launcher with working fluid, admitting the device into the launcher, pumping the working fluid in the direction and at the rate desired so that the device moves through the piping system for pipe cleaning or inspection, removing the device from the launcher, and collecting the working fluid contained in the launcher. 8 figs.

  20. Piping stress handbook

    SciTech Connect

    Heiguero, V.M.

    1985-01-01

    This new edition brings together in one source the formulas and technical data that previously had to be gathered from many scattered sources. The mathematical complexity of refinery, petrochemical, and power-plant piping design requires the use of many highly sophisticated computer programs, all of which require extensive input. The tables in this handbook not only provide these necessary input data but also help check the accuracy of the program output, eliminate interpolation, and reduce expensive ''engineering time''. New Material in this second edition covers piping branch reinforcements and stiffness coefficients for nozzles on cylindrical vessels. In addition, it includes the latest ANSI Piping Codes B31.1(1983) and B31.3(1984).

  1. Composite drill pipe

    DOEpatents

    Leslie, James C. (Fountain Valley, CA); Leslie, II, James C. (Mission Viejo, CA); Heard, James (Huntington Beach, CA); Truong, Liem (Anaheim, CA), Josephson; Marvin (Huntington Beach, CA), Neubert; Hans (Anaheim, CA)

    2008-12-02

    A composite pipe segment is formed to include tapered in wall thickness ends that are each defined by opposed frustoconical surfaces conformed for self centering receipt and intimate bonding contact within an annular space between corresponding surfaces of a coaxially nested set of metal end pieces. The distal peripheries of the nested end pieces are then welded to each other and the sandwiched and bonded portions are radially pinned. The composite segment may include imbedded conductive leads and the axial end portions of the end pieces are shaped to form a threaded joint with the next pipe assembly that includes a contact ring in one pipe assembly pierced by a pointed contact in the other to connect the corresponding leads across the joint.

  2. Piping systems physical benchmarks

    SciTech Connect

    Bezler, P.; Subudhi, M.

    1985-01-01

    Physical benchmark evaluations are used to assess the accuracy and adequacy of the analysis methods and assumptions used in typical piping qualification evaluations. To date physical benchmark evaluations have been completed for five systems involving both laboratory tested and in situ piping. In each evaluation elastic finite element methods are used to predict the time history response of a system for which physical test results are available. In the analytical simulations the measured support excitations and the measured damping properties are used as input and the acceleration and displacement response of piping interior points are predicted as output. Most evaluations were performed blind in that only the measured inputs are provided at the time of analysis. A summary of the overall results as well as predicted and measured time history traces for selected points are included.

  3. Apparatus for inspecting piping

    DOEpatents

    Zollingger, W.T.; Appel, D.K.; Park, L.R.

    1995-03-21

    An inspection rabbit is described for inspecting piping systems having severe bends therein. The rabbit consists of a flexible, modular body containing a miniaturized eddy current inspection probe, a self-contained power supply for proper operation of the rabbit, an outer surface that allows ease of movement through piping systems and means for transmitting data generated by the inspection device. The body is preferably made of flexible polyvinyl chloride (PVC) tubing or, alternatively, silicone rubber with a shrink wrapping of polytetrafluoroethylene (TEFLON{trademark}). The body is formed to contain the power supply, preferably a plurality of batteries, and a spool of communication wire that connects to a data processing computer external to the piping system. 6 figures.

  4. Apparatus for inspecting piping

    DOEpatents

    Zollingger, W. Thor (Martinez, GA); Appel, D. Keith (Aiken, SC); Park, Larry R. (Raleigh, NC)

    1995-01-01

    An inspection rabbit for inspecting piping systems having severe bends therein. The rabbit consists of a flexible, modular body containing a miniaturized eddy current inspection probe, a self-contained power supply for proper operation of the rabbit, an outer surface that allows ease of movement through piping systems and means for transmitting data generated by the inspection device. The body is preferably made of flexible polyvinyl chloride (PVC) tubing or, alternatively, silicone rubber with a shrink wrapping of polytetrafluoroethylene (TEFLON.RTM.). The body is formed to contain the power supply, preferably a plurality of batteries, and a spool of communication wire that connects to a data processing computer external to the piping system.

  5. Heat-pipe Earth.

    PubMed

    Moore, William B; Webb, A Alexander G

    2013-09-26

    The heat transport and lithospheric dynamics of early Earth are currently explained by plate tectonic and vertical tectonic models, but these do not offer a global synthesis consistent with the geologic record. Here we use numerical simulations and comparison with the geologic record to explore a heat-pipe model in which volcanism dominates surface heat transport. These simulations indicate that a cold and thick lithosphere developed as a result of frequent volcanic eruptions that advected surface materials downwards. Declining heat sources over time led to an abrupt transition to plate tectonics. Consistent with model predictions, the geologic record shows rapid volcanic resurfacing, contractional deformation, a low geothermal gradient across the bulk of the lithosphere and a rapid decrease in heat-pipe volcanism after initiation of plate tectonics. The heat-pipe Earth model therefore offers a coherent geodynamic framework in which to explore the evolution of our planet before the onset of plate tectonics. PMID:24067709

  6. Piping-System Solutions Using Mathcad

    E-print Network

    Kostic, Milivoje M.

    Piping-System Solutions Using Mathcad B. K. HODGE,1 ROBERT P. TAYLOR2 1 Mechanical Engineering associated with piping systems. Examples include series piping systems, parallel piping systems, and pipingScience (www.interscience.wiley.com.); DOI 10.1002/cae.10010 Keywords: piping systems; Mathcad, Hardy

  7. Heat pipe applications development in Europe

    Microsoft Academic Search

    O. Brost; W. D. Muenzel

    1975-01-01

    Heat pipes for the cryogenic temperature range are considered along with low temperature heat pipes, heat pipes in the mid-temperature range, and heat pipes in the high temperature range. A description of structures for high performance heat pipes is presented. The characteristics of isothermal spaces obtained by the use of simple heat pipes are examined, taking into account isothermal inserts,

  8. Tippy Tap Plus Piping

    NSDL National Science Digital Library

    2014-09-18

    The Tippy Tap hand-washing station is an inexpensive and effective device used extensively in the developing world. One shortcoming of the homemade device is that it must be manually refilled with water and therefore is of limited use in high-traffic areas. In this activity, student teams design, prototype and test piping systems to transport water from a storage tank to an existing Tippy Tap hand-washing station, thereby creating a more efficient hand-washing station. Through this example service-learning engineering project, students learn basic fluid dynamic principles that are needed for creating efficient piping systems.

  9. Heat transfer in pipes

    NASA Astrophysics Data System (ADS)

    Burbach, T.

    1985-04-01

    The heat transfer from hot water to a cold copper pipe in laminar and turbulent flow condition is determined. The mean flow through velocity in the pipe, relative test length and initial temperature in the vessel were varied extensively during tests. Measurements confirm Nusselt's theory for large test lengths in laminar range. A new equation is derived for heat transfer for large starting lengths which agrees satisfactorily with measurements for large starting lengths. Test results are compared with the new Prandtl equation for heat transfer and correlated well. Test material for 200- and to 400-diameter test length is represented at four different vessel temperatures.

  10. Heat transfer in pipes

    NASA Technical Reports Server (NTRS)

    Burbach, T.

    1985-01-01

    The heat transfer from hot water to a cold copper pipe in laminar and turbulent flow condition is determined. The mean flow through velocity in the pipe, relative test length and initial temperature in the vessel were varied extensively during tests. Measurements confirm Nusselt's theory for large test lengths in laminar range. A new equation is derived for heat transfer for large starting lengths which agrees satisfactorily with measurements for large starting lengths. Test results are compared with the new Prandtl equation for heat transfer and correlated well. Test material for 200- and to 400-diameter test length is represented at four different vessel temperatures.

  11. Fabrication and test of a thermopneumatic micropump with a corrugated p+ diaphragm

    Microsoft Academic Search

    Ok Chan Jeong; Sang Sik Yang

    2000-01-01

    This paper presents a thermopneumatic micropump fabricated by micromachining. The micropump consists of a p+ silicon diaphragm, a micro heater and a pair of nozzle\\/diffuser. The thermopneumatic actuator of this paper is characterized by a corrugated diaphragm, which is more flexible than a flat one. The diaphragm is driven by the air cavity pressure variation caused by the ohmic heating

  12. On the Wave Propagation and Mode Conversion in a Helically Corrugated Multimode Circular Waveguide

    Microsoft Academic Search

    C. C. H. Tang

    1966-01-01

    For specific forms of excitations, the normal modes and mode coefficients of a lossless helically corrugated circular multimode waveguide are determined from the appropriate boundary conditions. Because of the multiplicity of the roots of the characteristic dispersion equation obtained, care must be exercised in the evaluation of the equation and in the interpretation of the ?-? diagram. For the TE11

  13. Numerical simulation of flow of shear-thinning fluids in corrugated channels

    E-print Network

    Aiyalur Shankaran, Rohit

    2009-05-15

    A numerical study of flow of a shear thinning fluid through a pair of corrugated plates was carried out. The aim of the study was to observe and understand the behavior of the flow of shear thinning fluids through channels were the fluid...

  14. Direct Acceleration of Electrons in a Corrugated Plasma Waveguide A. G. York* and H. M. Milchberg

    E-print Network

    Milchberg, Howard

    Direct Acceleration of Electrons in a Corrugated Plasma Waveguide A. G. York* and H. M. Milchberg) Historically, direct acceleration of charged particles by electromagnetic fields has been limited- field acceleration of electrons over many centimeters using relatively small femtosecond lasers. We

  15. Conductor load bearing roller for a gas-insulated transmission line having a corrugated outer conductor

    DOEpatents

    Fischer, William H. (Pittsburgh, PA); Yoon, Kue H. (Pittsburgh, PA)

    1984-04-10

    A gas-insulated transmission line includes a corrugated outer conductor, an inner conductor disposed within and insulated from the outer conductor by means of support insulators and an insulating gas, and a transport device for supporting and permitting movement of the inner conductor/insulating support assembly axially along the corrugated outer conductor without radial displacement. The transport device includes two movable contacts, such as skids or rollers, supported on a common pivot lever, the pivot lever being rotatably disposed about a pivot lever axis, which pivot lever axis is in turn disposed on the periphery of a support insulator or particle trap if one is used. The movable contacts are separated axially a distance equal to the axial distance between the peaks and valleys of the corrugations of the outer conductor and separated radially a distance equal to the radial distance between the peaks and valleys of the corrugations of the outer conductor. The transport device has the pivot lever axis disposed perpendicular to the direction of travel of the inner conductor/insulating support assembly.

  16. A study for sound wave scattering by corrugated ground with complex trench structures

    Microsoft Academic Search

    Mei Song Tong; Leon Yeow Ting; Weng Cho Chew; Michael J. White

    2009-01-01

    Several trench structures in corrugated ground are investigated for the possibility of mitigating gun blast noise by numerical simulations. The blast noise usually includes large explosive energy with nonlinearity in the near field and exhibits a very low-frequency spectrum. In this study, the linearity approximation for the noise is taken because the nonlinearity of the wave reaching the scatterer is

  17. Method for producing ultrafine-grained materials using repetitive corrugation and straightening

    DOEpatents

    Zhu, Yuntian T. (Los Alamos, NM); Lowe, Terry C. (Santa Fe, NM); Jiang, Honggang (Los Alamos, NM); Huang, Jianyu (Los Alamos, NM)

    2001-01-01

    A method of refining the grain structure and improving the hardness and strength properties of a metal or metal alloy workpiece is disclosed. The workpiece is subjected to forces that corrugate and then straighten the workpiece. These steps are repeated until an ultrafine-grained product having improved hardness and strength is produced.

  18. Experimental and theoretical investigation of angular dependence of the Casimir force between sinusoidally corrugated surfaces

    E-print Network

    A. A. Banishev; J. Wagner; T. Emig; R. Zandi; U. Mohideen

    2014-06-16

    In the current work we present the complete results for the measurement of normal Casimir force between shallow and smooth sinusoidally corrugated gold coated sphere and a plate at various angles between the corrugations using an atomic force microscope. All measured data were compared with the theoretical approach using the proximity force approximation and theory based on derivative expansion. In both cases real material properties of the surfaces and non-zero temperature were taken into account. Special attention is paid to the description of electrostatic interactions between corrugated surfaces at different angels between corrugations and samples reparation and characterization. The measured forces are found to be in good agreement with the theory including correlation effects of geometry and material properties and deviate significantly from the predictions of the proximity force approximation approach. This provides the quantitative confirmation for the observation of diffraction-type effects that are disregarded within the PFA approach. The obtained results open new opportunities for control of the Casimir effect in micromechanical systems.

  19. Low voltage and high transmittance blue-phase liquid crystal displays with corrugated electrodes

    E-print Network

    Wu, Shin-Tson

    Low voltage and high transmittance blue-phase liquid crystal displays with corrugated electrodes January 2010 A low voltage 10 V and high transmittance 85.6% polymer-stabilized blue-phase liquid crystal along the beam path is large, resulting in low voltage and high transmittance. This approach enables

  20. Multi-sheet corrugated tank construction for passive solar heating systems

    Microsoft Academic Search

    Buckley

    1984-01-01

    A passive solar heating liquid storage tank is formed of multiple thin sheets of thermoplastic or thermoset material to provide a lightweight, inexpensive and high volume tank. The multiple sheets have a plurality of parallel undulations or corrugations transverse to their surfaces. The undulations form spacial wave trains of given amplitude and frequency so that when their peaks are secured

  1. Experimental and theoretical investigation of the angular dependence of the Casimir force between sinusoidally corrugated surfaces

    NASA Astrophysics Data System (ADS)

    Banishev, A. A.; Wagner, J.; Emig, T.; Zandi, R.; Mohideen, U.

    2014-06-01

    In the current work we present the complete results for the measurement of normal Casimir force between a shallow and smooth sinusoidally corrugated gold coated sphere and a plate at various angles between the corrugations using an atomic force microscope. All measured data were compared with the theoretical approach using the proximity force approximation and theory based on derivative expansion. In both cases real material properties of the surfaces and nonzero temperature were taken into account. Special attention is paid to the description of electrostatic interactions between corrugated surfaces at different angles between corrugations and samples preparation and characterization. The measured forces are found to be in good agreement with the theory including correlation effects of geometry and material properties and deviate significantly from the predictions of the proximity force approximation approach. This provides the quantitative confirmation for the observation of diffraction-type effects that are disregarded within the PFA approach. The obtained results open new opportunities for control of the Casimir effect in micromechanical systems.

  2. Flat-plate heat pipe

    NASA Technical Reports Server (NTRS)

    Marcus, B. D.; Fleischman, G. L. (inventors)

    1977-01-01

    Flat plate (vapor chamber) heat pipes were made by enclosing metal wicking between two capillary grooved flat panels. These heat pipes provide a unique configuration and have good capacity and conductance capabilities in zero gravity. When these flat plate vapor chamber heat pipes are heated or cooled, the surfaces are essentially isothermal, varying only 3 to 5 C over the panel surface.

  3. Adjustable-angle pipe fitting

    SciTech Connect

    Kronberg, J.W.

    1991-01-01

    This invention pertains to a pipe fitting for joining two pipes at a desired, preselected angle and comprises a curved section of pipe with a generally circular cross-section. One end of the curved pipe is preferably furnished with a bell fitting. The other end is adapted to be inserted into the bell of another pipe fitting. The surface of the pipe is marked with circumferential lines spaced at several-degree intervals, the lines corresponding to the angle of the bend which will result if the pipe is cut along that line. The outer diameter of the pipe is closely controlled to be the same throughout its length as the outer diameter of a straight pipe, so the cut end can be inserted into the bell of another fitting without further treatment, and the radius of curvature of the pipe is larger than a standard street elbow, preferably three to ten times the diameter of the pipe. Thus, a cut approximately perpendicular to the axial centerline can be made at any point along the length of the pipe to form an elbow of any desired angle.

  4. Adjustable-angle pipe fitting

    SciTech Connect

    Kronberg, J.W.

    1991-12-31

    This invention pertains to a pipe fitting for joining two pipes at a desired, preselected angle and comprises a curved section of pipe with a generally circular cross-section. One end of the curved pipe is preferably furnished with a bell fitting. The other end is adapted to be inserted into the bell of another pipe fitting. The surface of the pipe is marked with circumferential lines spaced at several-degree intervals, the lines corresponding to the angle of the bend which will result if the pipe is cut along that line. The outer diameter of the pipe is closely controlled to be the same throughout its length as the outer diameter of a straight pipe, so the cut end can be inserted into the bell of another fitting without further treatment, and the radius of curvature of the pipe is larger than a standard street elbow, preferably three to ten times the diameter of the pipe. Thus, a cut approximately perpendicular to the axial centerline can be made at any point along the length of the pipe to form an elbow of any desired angle.

  5. Heat pipes for space projects

    Microsoft Academic Search

    H. Kreeb; H. Koch

    1981-01-01

    Heat pipes with a capillary structure consisting of axial grooves are discussed which are intended for use in various space vehicles. The heat pipes are produced from a modular system that has more than 15 pipe geometries for both standard and cryogenic temperatures and is based on the concept of an extruded aluminum profile with longitudinal grooves serving as capillaries.

  6. Reusable high-temperature heat pipes and heat pipe panels

    NASA Technical Reports Server (NTRS)

    Camarda, Charles J. (inventor); Ransone, Philip O. (inventor)

    1989-01-01

    A reusable, durable heat pipe which is capable of operating at temperatures up to about 3000 F in an oxidizing environment and at temperatures above 3000 F in an inert or vacuum environment is produced by embedding a refractory metal pipe within a carbon-carbon composite structure. A reusable, durable heat pipe panel is made from an array of refractory-metal pipes spaced from each other. The reusable, durable, heat-pipe is employed to fabricate a hypersonic vehicle leading edge and nose cap.

  7. Defect characterization in pipe-to-pipe welds in large diameter stainless steel piping

    SciTech Connect

    Rawl, D.E. Jr.; West, S.L.; Wheeler, D.A.; Louthan, M.R. Jr.

    1990-01-01

    Metallurgical evaluation of pipe-to-pipe welds in large-diameter, Type 304 stainless steel piping used to construct the moderator/coolant water systems for Savannah River Site reactors has demonstrated that small weld defects found in this 1950-vintage system do not compromise the integrity of the system. The weld defects were too small for detection by the pre-service standard radiographic inspection, but were found through systematic ultrasonic testing (UT) and penetrant testing (PT) evaluations of piping that had been removed during upgrades to the piping system. The defects include lack of weld penetration, slag inclusions, and other weld metal discontinuities. These discontinuities typically did not propagate during more than 35 years of service. The defects examined were too small and isolated to degrade the mechanical properties of the pipe-to-pipe weldments and therefore did not compromise the integrity of the piping system. 14 refs., 7 figs.

  8. Piping stress handbook

    Microsoft Academic Search

    Heiguero

    1985-01-01

    This new edition brings together in one source the formulas and technical data that previously had to be gathered from many scattered sources. The mathematical complexity of refinery, petrochemical, and power-plant piping design requires the use of many highly sophisticated computer programs, all of which require extensive input. The tables in this handbook not only provide these necessary input data

  9. Acme jumper pipe

    SciTech Connect

    Medved, P.; Thomas, H. [Acme Steel Co., Chicago, IL (United States)

    1995-09-01

    Acme Steel had operated the larry car with an attached jumper pipe since 1977. Acme had been able to meet the State Implementation Plan. With the advent of the Clean Air Act, Acme did not feel it could meet these new standards without some modifications to the jumper pipe system. Several drop sleeve modifications and numerous boot seal materials and configurations were tested that resulted in limited success in improving the boot seal life. After these modifications, Acme`s testing revealed it could meet the Clean Air Act standards, but it would be cost prohibitive to continue to operate in this manner. Following extensive investigation, Acme decided to install an off-car jumper pipe system which uses a traveling U-tube for connecting to the assist oven through an additional hole in each oven roof. Temperature related failures of drop sleeve seals were eliminated. The off-car jumper pipe is a more efficient gas connection to the assist oven and enables Acme to meet the Clean Air Act charging requirements in a cost effective manner.

  10. Aeronautical tubes and pipes

    NASA Astrophysics Data System (ADS)

    Beauclair, N.

    1984-12-01

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

  11. Explosive Welding of Pipes

    NASA Astrophysics Data System (ADS)

    Drennov, Oleg; Drennov, Andrey; Burtseva, Olga

    2013-06-01

    For connection by welding it is suggested to use the explosive welding method. This method is rather new. Nevertheless, it has become commonly used among the technological developments. This method can be advantageous (saving material and physical resources) comparing to its statical analogs (electron-beam welding, argon-arc welding, plasma welding, gas welding, etc.), in particular, in hard-to-reach areas due to their geographic and climatic conditions. Explosive welding of cylindrical surfaces is performed by launching of welded layer along longitudinal axis of construction. During this procedure, it is required to provide reliable resistance against radial convergent strains. The traditional method is application of fillers of pipe cavity, which are dense cylindrical objects having special designs. However, when connecting pipes consecutively in pipelines by explosive welding, removal of the fillers becomes difficult and sometimes impossible. The suggestion is to use water as filler. The principle of non-compressibility of liquid under quasi-dynamic loading is used. In one-dimensional gasdynamic and elastic-plastic calculations we determined non-deformed mass of water (perturbations, which are moving in the axial direction with sound velocity, should not reach the layer end boundaries for 5-7 circulations of shock waves in the radial direction). Linear dimension of the water layer from the zone of pipe coupling along axis in each direction is >= 2R, where R is the internal radius of pipe.

  12. Analysis of a disk-on-rod surface wave element inside a corrugated horn using the mode-matching technique

    NASA Technical Reports Server (NTRS)

    Chen, J. C.

    1995-01-01

    A disk-on-rod inside a corrugated horn is one of the horn configurations for dual-frequency or wide-band operation. A mode-matching analysis method is described. A disk-on-rod inside a corrugated horn is represented as a series of coaxial waveguide sections and circular waveguide sections connected to each other. Three kinds of junctions need to be considered: coaxial-to-coaxial, coaxial-to-circular, and circular-to-circular. A computer program was developed to calculate the scattering matrix and the radiation pattern of a disk-on-rod inside a corrugated horn. The software as verified by experiment, and good agreement between calculation and measurement was obtained. The disk-on-rod inside a corrugated horn design gives an option to the Deep Space Network dual-frequency operation system, which currently is a two-horn/one-dichroic plate system.

  13. Drill pipe protector development

    SciTech Connect

    Thomerson, C.; Kenne, R. [Regal International Corp., Corsicanna, TX (United States); Wemple, R.P. [Sandia National Lab., Albuquerque, NM (United States)] [ed.] [and others

    1996-03-01

    The Geothermal Drilling Organization (GDO), formed in the early 1980s by the geothermal industry and the U.S. Department of Energy (DOE) Geothermal Division, sponsors specific development projects to advance the technologies used in geothermal exploration, drilling, and production phases. Individual GDO member companies can choose to participate in specific projects that are most beneficial to their industry segment. Sandia National Laboratories is the technical interface and contracting office for the DOE in these projects. Typical projects sponsored in the past have included a high temperature borehole televiewer, drill bits, muds/polymers, rotary head seals, and this project for drill pipe protectors. This report documents the development work of Regal International for high temperature geothermal pipe protectors.

  14. Dispersion relation and growth rate in thermal plasma-loaded traveling wave tube with corrugated waveguide hollow electron beam

    NASA Astrophysics Data System (ADS)

    Dehghanizadeh, Samina; Saviz, Shahrooz

    2015-02-01

    A theory of relativistic traveling wave tube with magnetized thermal plasma-filled corrugated waveguide with annular electron beam is given. The dispersion relation is obtained by linear fluid theory. The characteristic of the dispersion relation is obtained by numerical solutions. The effect of plasma density, corrugated period, waveguide radius and plasma thermal effect on the dispersion relation and growth rate are analyzed. Some useful results are given.

  15. Numerical simulation and optimization of single-phase turbulent flow in chevron-type plate heat exchanger with sinusoidal corrugations

    Microsoft Academic Search

    Weizhe Han; Khaled Saleh; Vikrant Aute; Guoliang Ding; Yunho Hwang; Reinhard Radermacher

    2011-01-01

    The thermal-hydrodynamic characteristics of a single-phase turbulent flow in chevron-type plate heat exchangers with sinusoidal-shaped corrugations have been numerically investigated in this article. The computational domain contains a corrugation channel, and the simulations adopted the shear-stress transport ?-? model as the turbulence model. The numerical simulation results in terms of Nusselt number and friction factor were compared with limited experimental

  16. Flow and heat\\/mass transfer in a wavy duct with various corrugation angles in two dimensional flow regimes

    Microsoft Academic Search

    Hyun Goo Kwon; Sang Dong Hwang; Hyung Hee Cho

    2008-01-01

    In this study, two dimensional heat\\/mass transfer characteristics and flow features were investigated in a rectangular wavy\\u000a duct with various corrugation angles. The test duct had a width of 7.3 mm and a large aspect ratio of 7.3 to simulate two\\u000a dimensional characteristics. The corrugation angles used were 100°, 115°, 130°, and 145°. Numerical analysis using the commercial\\u000a code FLUENT,

  17. Flow and heat\\/mass transfer in a wavy duct with various corrugation angles in two dimensional flow regimes

    Microsoft Academic Search

    Hyun Goo Kwon; Sang Dong Hwang; Hyung Hee Cho

    2008-01-01

    In this study, two dimensional heat\\/mass transfer characteristics and flow features were investigated in a rectangular wavy duct with various corrugation angles. The test duct had a width of 7.3 mm and a large aspect ratio of 7.3 to simulate two dimensional characteristics. The corrugation angles used were 100°, 115°, 130°, and 145°. Numerical analysis using the commercial code FLUENT,

  18. Particle trap to sheath contact for a gas-insulated transmission line having a corrugated outer conductor

    DOEpatents

    Fischer, William H. (Pittsburgh, PA); Cookson, Alan H. (Pittsburgh, PA); Yoon, Kue H. (Pittsburgh, PA)

    1984-04-10

    A particle trap to outer elongated conductor or sheath contact for gas-insulated transmission lines. The particle trap to outer sheath contact of the invention is applicable to gas-insulated transmission lines having either corrugated or non-corrugated outer sheaths. The contact of the invention includes an electrical contact disposed on a lever arm which in turn is rotatably disposed on the particle trap and biased in a direction to maintain contact between the electrical contact and the outer sheath.

  19. Pipe inspection using the pipe crawler. Innovative technology summary report

    SciTech Connect

    NONE

    1999-05-01

    The US Department of Energy (DOE) continually seeks safer and more cost-effective remediation technologies for use in the decontamination and decommissioning (D and D) of nuclear facilities. In several of the buildings at the Fernald Site, there is piping that was used to transport process materials. As the demolition of these buildings occur, disposal of this piping has become a costly issue. Currently, all process piping is cut into ten-foot or less sections, the ends of the piping are wrapped and taped to prevent the release of any potential contaminants into the air, and the piping is placed in roll off boxes for eventual repackaging and shipment to the Nevada Test Site (NTS) for disposal. Alternatives that allow for the onsite disposal of process piping are greatly desired due to the potential for dramatic savings in current offsite disposal costs. No means is currently employed to allow for the adequate inspection of the interior of piping, and consequently, process piping has been assumed to be internally contaminated and thus routinely disposed of at NTS. The BTX-II system incorporates a high-resolution micro color camera with lightheads, cabling, a monitor, and a video recorder. The complete probe is capable of inspecting pipes with an internal diameter (ID) as small as 1.4 inches. By using readily interchangeable lightheads, the same system is capable of inspecting piping up to 24 inches in ID. The original development of the BTX system was for inspection of boiler tubes and small diameter pipes for build-up, pitting, and corrosion. However, the system is well suited for inspecting the interior of most types of piping and other small, confined areas. The report describes the technology, its performance, uses, cost, regulatory and policy issues, and lessons learned.

  20. Guidable pipe plug

    DOEpatents

    Glassell, Richard L. (Knoxville, TN); Babcock, Scott M. (Farragut, TN); Lewis, Benjamin E. (Farragut, TN)

    2001-01-01

    A plugging device for closing an opening defined by an end of a pipe with sealant comprises a cap, an extension, an inner seal, a guide, and at least one stop. The cap has an inner surface which defines a chamber adapted for retaining the sealant. The chamber is dimensioned slightly larger than the end so as to receive the end. The chamber and end define a gap therebetween. The extension has a distal end and is attached to the inner surface opposite the distal end. The inner seal is attached to the extension and sized larger than the opening. The guide is positioned forward of the inner seal and attached to the distal end. The guide is also dimensioned to be inserted into the opening. The stop is attached to the extender, and when the stop is disposed in the pipe, the stop is movable with respect to the conduit in one direction and also prevents misalignment of the cap with the pipe. A handle can also be included to allow the cap to be positioned robotically.

  1. 46 CFR 76.33-15 - Piping.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Piping. 76.33-15 Section 76.33-15...Detecting System, Details § 76.33-15 Piping. (a) Individual pipes shall be not...inch standard pipe size. (b) All piping, valves, and fittings of...

  2. 46 CFR 76.33-15 - Piping.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Piping. 76.33-15 Section 76.33-15...Detecting System, Details § 76.33-15 Piping. (a) Individual pipes shall be not...inch standard pipe size. (b) All piping, valves, and fittings of...

  3. 46 CFR 76.33-15 - Piping.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Piping. 76.33-15 Section 76.33-15...Detecting System, Details § 76.33-15 Piping. (a) Individual pipes shall be not...inch standard pipe size. (b) All piping, valves, and fittings of...

  4. Page 1 of 1 Pipe School

    E-print Network

    Texas at Arlington, University of

    Page 1 of 1 Track B Pipe School© Sunday, January 22, 2012 Hilton Palacio Del Rio, San Antonio Selection, Terry McArthur, P.E., HDR, Inc. 9:00 Pipe Materials, Terry McArthur, P.E., HDR, Inc. 9:30 Pipe:15 Principles of Pipeline Design and Construction ­ Rigid and Flexible Pipes, Shah Rahman, Northwest Pipe

  5. Heat pipe technology: A bibliography with abstracts

    NASA Technical Reports Server (NTRS)

    1971-01-01

    The annual supplement on heat pipe technology for 1971 is presented. The document contains 101 references with abstracts and 47 patents. The subjects discussed are: (1) heat pipe applications, (2) heat pipe theory, (3) design, development, and fabrication of heat pipes, (4) testing and operation, (5) subject and author index, and (6) heat pipe related patents.

  6. Use of a corrugated surface to enhance radiation tolerance in a GaAs solar cell

    NASA Technical Reports Server (NTRS)

    Leon, Rosa P.; Piszczor, Michael F., Jr.

    1985-01-01

    The use of a corrugated surface on a GaAs solar cell and its effects on radiation resistance were studied. A compute code was developed to determine the performance of the cell for various geometric parameters. The large optical absorption coefficient of GaAs allows grooves to be only 4-5 micrometers deep. Using accepted material parameters for GaAs solar cells the theoretical performances were compared for various corrugated cells before and after minority carrier diffusion length degradation. The total power output was maximized for both n(+)/p and p(+)/n cells. Optimum values of 1.0-1.5 and 5.0 micrometers for groove and ridge widths respectively were determined.

  7. The scattering of obliquely incident plane waves from a corrugated conducting surface

    NASA Technical Reports Server (NTRS)

    Le Vine, D. M.

    1976-01-01

    A physical optics solution is presented for the scattering of plane waves from a perfectly conducting corrugated surface in the case of waves incident from an arbitrary direction and for an observer far from the surface. This solution is used to compute the radar cross section of the surface in the case of backscatter from irregular (i.e., stochastic) corrugations. An interesting feature of the solution is the occurrence of singularities in the scattered fields. These singularities appear to be a manifestation of focusing by the surface at its 'stationary' points. Whether or not the singularities occur in the solution depends on the manner in which one restricts the analysis to the far-field.

  8. Enhanced response and sensitivity of self-corrugated graphene sensors with anisotropic charge distribution

    PubMed Central

    Yol Jeong, Seung; Jeong, Sooyeon; Won Lee, Sang; Tae Kim, Sung; Kim, Daeho; Jin Jeong, Hee; Tark Han, Joong; Baeg, Kang-Jun; Yang, Sunhye; Seok Jeong, Mun; Lee, Geon-Woong

    2015-01-01

    We introduce a high-performance molecular sensor using self-corrugated chemically modified graphene as a three dimensional (3D) structure that indicates anisotropic charge distribution. This is capable of room-temperature operation, and, in particular, exhibiting high sensitivity and reversible fast response with equilibrium region. The morphology consists of periodic, “cratered” arrays that can be formed by condensation and evaporation of graphene oxide (GO) solution on interdigitated electrodes. Subsequent hydrazine reduction, the corrugated edge area of the graphene layers have a high electric potential compared with flat graphene films. This local accumulation of electrons interacts with a large number of gas molecules. The sensitivity of 3D-graphene sensors significantly increases in the atmosphere of NO2 gas. The intriguing structures have several advantages for straightforward fabrication on patterned substrates, high-performance graphene sensors without post-annealing process. PMID:26053892

  9. Structural testing of corrugated asbestos-cement roof panels at the Hanford Facilities, Richland, Washington

    SciTech Connect

    Moustafa, S.E.; Rodehaver, S.M. [Wiss, Janney, Elstner Associates, Inc., Seattle, WA (United States); Frier, W.A. [Westinghouse Hanford Co., Richland, WA (United States)

    1993-10-01

    This report describes a roof testing program that was carried out at the 105KE/KW Spent Fuel Storage Basins and their surrounding facilities at the Hanford Site in Richland, Washington. The roof panels were constructed in the mid 1950`s of corrugated asbestos-cement (A/C), which showed common signs of aging. Based on the construction specifications, the panels capacity to meet current design standards was questioned. Both laboratory and in-situ load testing of the corrugated A/C panels was conducted. The objective of the complete test program was to determine the structural integrity of the existing A/C roof panels installed in the 105KE and 105KW facilities. The data from these tests indicated that the roofs are capable of resisting the design loads and are considered safe. A second phase test to address the roof resistance to personnel and roof removal/roofing system installation equipment was recommended and is underway.

  10. The scatter of obliquely incident plane waves from a corrugated conducting surface

    NASA Technical Reports Server (NTRS)

    Levine, D. N.

    1975-01-01

    A physical optics solution is presented for the scattering of plane waves from a perfectly conducting corrugated surface in the case of waves incident from an arbitrary direction and for an observer far from the surface. This solution was used to compute the radar cross section of the surface in the case of backscatter from irregular (i.e., stochastic) corrugations and to point out a correction to the literature on this problem. A feature of the solution is the occurrence of singularities in the scattered fields which appear to be a manifestation of focussing by the surface at its stationary points. Whether or not the singularities occur in the solution depends on the manner in which one restricts the analysis to the far field.

  11. Focused ion beam lithography for fabrication of suspended nanostructures on highly corrugated surfaces

    NASA Astrophysics Data System (ADS)

    Erdmanis, M.; Sievilä, P.; Shah, A.; Chekurov, N.; Ovchinnikov, V.; Tittonen, I.

    2014-08-01

    We propose a nanofabrication method that allows for patterning on extremely corrugated surfaces with micrometer-size features. The technique employs focused ion beam nanopatterning of ion-sensitive inorganic resists formed by atomic layer deposition at low temperature. The nanoscale resolution on corrugated surfaces is ensured by inherently large depth of focus of a focused ion beam system and very uniform resist coating. The utilized TiO2 and Al2O3 resists show high selectivity in deep reactive ion etching and enable the release of suspended nanostructures by dry etching. We demonstrate the great flexibility of the process by fabricating suspended nanostructures on flat surfaces, inclined walls, and on the bottom of deep grooves.

  12. Focused ion beam lithography for fabrication of suspended nanostructures on highly corrugated surfaces.

    PubMed

    Erdmanis, M; Sievilä, P; Shah, A; Chekurov, N; Ovchinnikov, V; Tittonen, I

    2014-08-22

    We propose a nanofabrication method that allows for patterning on extremely corrugated surfaces with micrometer-size features. The technique employs focused ion beam nanopatterning of ion-sensitive inorganic resists formed by atomic layer deposition at low temperature. The nanoscale resolution on corrugated surfaces is ensured by inherently large depth of focus of a focused ion beam system and very uniform resist coating. The utilized TiO? and Al?O? resists show high selectivity in deep reactive ion etching and enable the release of suspended nanostructures by dry etching. We demonstrate the great flexibility of the process by fabricating suspended nanostructures on flat surfaces, inclined walls, and on the bottom of deep grooves. PMID:25074238

  13. The Influence of Railpad Stiffness on Wheelset/track Interaction and Corrugation Growth

    NASA Astrophysics Data System (ADS)

    ILIAS, H.

    1999-11-01

    The aim of the paper is to investigate the influence of the railpad stiffness on vehicle/track interaction and corrugation growth. For the structural dynamics of vehicle and track a time domain model is used which includes all relevant contact non-linearities. A simple war model enables profile development calculations to be undertaken in the time domain by closing the feedback loop between a short-term dynamical process (structural dynamics) and a long-term damaging process (wear). The initial profile is taken from measurements of a ground rail. It is found that stiffer railpads lead to higher corrugation growth. The parametric excitation from passing sleepers is found to be important. For the chosen operational values this wavelength-fixing mechanism dominates the so-called final profiles of profile development calculations.

  14. Enhanced response and sensitivity of self-corrugated graphene sensors with anisotropic charge distribution.

    PubMed

    Yol Jeong, Seung; Jeong, Sooyeon; Won Lee, Sang; Tae Kim, Sung; Kim, Daeho; Jin Jeong, Hee; Tark Han, Joong; Baeg, Kang-Jun; Yang, Sunhye; Seok Jeong, Mun; Lee, Geon-Woong

    2015-01-01

    We introduce a high-performance molecular sensor using self-corrugated chemically modified graphene as a three dimensional (3D) structure that indicates anisotropic charge distribution. This is capable of room-temperature operation, and, in particular, exhibiting high sensitivity and reversible fast response with equilibrium region. The morphology consists of periodic, "cratered" arrays that can be formed by condensation and evaporation of graphene oxide (GO) solution on interdigitated electrodes. Subsequent hydrazine reduction, the corrugated edge area of the graphene layers have a high electric potential compared with flat graphene films. This local accumulation of electrons interacts with a large number of gas molecules. The sensitivity of 3D-graphene sensors significantly increases in the atmosphere of NO2 gas. The intriguing structures have several advantages for straightforward fabrication on patterned substrates, high-performance graphene sensors without post-annealing process. PMID:26053892

  15. Separate determination of liquid density and viscosity with sagittally corrugated Love-mode sensors

    Microsoft Academic Search

    F. Herrmann; D. Hahn; S. Büttgenbach

    1999-01-01

    A novel microacoustic sensor is reported for separate determination of liquid density and viscosity. The device is based on a layered quartz\\/SiO2-system with sagittal corrugations, supporting acoustic waveguide Love-modes. The sensor combines the merits of Love-mode devices, e.g., robustness and high sensitivity, with liquid trapping as an effective approach to separate density and viscosity influences on acoustic shear modes. The

  16. Coupled mode approach to square gradient Bragg reflection resonances in corrugated dielectric waveguides

    E-print Network

    Dietz, Otto; Neitzke, Oliver; Benson, Oliver

    2015-01-01

    We demonstrate the appearance of unexpected reflection resonances in corrugated dielectric waveguides. These are due to the curvature of the boundary. The effect is as strong as the ordinary Bragg resonances, and reduces the transmission through our waveguide by 20%. It is thus of high relevance for the design of optimized waveguiding structures. We validate our analytical predictions based on coupled mode theory by a comparison to numerical simulations.

  17. Molecular dynamics simulation of thin film growth on giant magnetoresistance corrugated structures

    Microsoft Academic Search

    Cheng-I. Weng; Chi-Chuan Hwang; Chia-Lin Chang; Jee-Gong Chang; Shin-Pon Ju

    2002-01-01

    This paper presents the use of molecular dynamics (MD) in simulating thin-film growth on giant magnetoresistance corrugated structures. The simulation model mainly concerns the deposition of Co atoms on a V-shape Cu substrate. The many-body, tight-binding potential model is utilized in the MD simulation to represent the interatomic force that exists between the atoms. The interface width is used to

  18. Corrugation-pitch-modulated MQW-DFB laser with narrow spectral linewidth (170 kHz)

    Microsoft Academic Search

    M. Okai; T. Tsuchiya; K. Uomi; N. Chinone; T. Harada

    1990-01-01

    A spectral linewidth of 170 kHz was achieved at a 1.5-?m wavelength in a 1200-?m long corrugation-pitch-modulated (CPM) distributed feedback (DFB) laser having multiple quantum wells (MQW). This is the narrowest linewidth ever reported for InGaAsP DFB lasers. The CPM structure is effective in maintaining the single longitudinal mode at a high output power by suppressing the spatial hole burning

  19. Wetting\\/dewetting transition of two-phase flows in nano-corrugated channels

    Microsoft Academic Search

    L. Biferale; R. Benzi; M. Sbragaglia; S. Succi; F. Toschi

    2007-01-01

    A lattice version of the Boltzmann kinetic equation for describing multi-phase flows in nano- and micro-corrugated devices\\u000a is reviewed. To this purpose, the Shan-Chen Lattice Boltzmann model [Phys. Rev. E 47, 1815 (1993)] for non-ideal fluids is extended to the case of confined geometries with hydrophobic properties on the wall.\\u000a This extended Shan-Chen method is applied for the simulation of

  20. MTR BUILDING, TRA603. EAST SIDE. CAMERA FACING WEST. CORRUGATED IRON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    MTR BUILDING, TRA-603. EAST SIDE. CAMERA FACING WEST. CORRUGATED IRON BUILDING MARKED WITH "X" IS TRA-651. TRA-626, TO ITS RIGHT, HOUSED COMPRESSOR EQUIPMENT FOR THE AIRCRAFT NUCLEAR PROPULSION PROGRAM. LATER, IT WAS USED FOR STORAGE. INL NEGATIVE NO. HD46-42-4. Mike Crane, Photographer, April 2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  1. Phase space tomography of cold-atoms dynamics in a weakly corrugated potential

    E-print Network

    Shuyu Zhou; Julien Chabé; Ran Salem; Tal David; David Groswasser; Mark Keil; Yonathan Japha; Ron Folman

    2014-09-23

    We demonstrate tomographic reconstruction of the phase space distribution of atoms oscillating in a harmonic trap with weak potential corrugation caused by nanoscale imperfections in an atom chip. We find that deformations in these distributions are highly sensitive to anharmonic components of the potential. They are explained in terms of angular velocity dispersion of isoenergetic phase space trajectories. We show that the method is applicable for probing classical and quantum dynamics of cold atoms, and we note its importance for future technological applications.

  2. Fabrication and evaluation of superplastically formed/weld-brazed corrugated compression panels with beaded webs

    NASA Technical Reports Server (NTRS)

    Royster, D. M.; Davis, R. C.; Shinn, J. M., Jr.; Bales, T. T.; Wiant, H. R.

    1985-01-01

    A study was made to investigate the feasibility of superplastically forming corrugated panels with beaded webs and to demonstrate the structural integrity of these panels by testing. The test panels in the study consist of superplastically formed titanium alloy Ti-6Al-4V half-hat elements that are joined by weld-brazing to titanium alloy Ti-6Al-4V caps to form either single-corrugation compression panels or multiple-corrugation compression panels. Stretching and subsequent thinning of the titanium sheet during superplastic forming is reduced by approximately 35 percent with a shallow half-hat die concept instead of a deep die concept and results in a more uniform thickness across the beaded webs. The complete panels are tested in end compression at room temperature and the results compared with analysis. The heavily loaded panels failed at loads approaching the yield strength of the titanium material. At maximum load, the caps wrinkled locally accompanied with separation of the weld-braze joint in the wrinkle. None of the panels tested, however, failed catastrophically in the weld-braze joint. Experimental test results are in good agreement with structural analysis of the panels.

  3. A numerical study of the effect of interwall spacing on turbulent flow in a corrugated duct

    SciTech Connect

    Ergin, S. [Istanbul Technical Univ. (Turkey). Faculty of Naval Architecture and Ocean Engineering; Ota, M.; Yamaguchi, H.; Sakamoto, M. [Tokyo Metropolitan Univ. (Japan). Dept. of Mechanical Engineering

    1996-12-31

    The effect of varying interwall spacing on periodic fully developed turbulent flow in a corrugated duct is studied numerically. The k-{var_epsilon} model is adopted for turbulent closure, and computations are performed for the ratio of the corrugation height to the interwall spacing ranging from 0.45 to 2.0, and for the corrugation angles of 30{degree} and 45{degree}. The Reynolds number ranges from 500 to 7,000 while the Prandtl number is 0.7. The numerical procedure and implementation of the {kappa}-{var_epsilon} model is validated by comparing numerical results with the experimental data directly. The results are also compared with the numerical values obtained by using a two-layer low-Reynolds number turbulence model. At a given Reynolds number, an increase in the interwall spacing increases the size of the separated region. On the other hand the friction factor first increases with the decreasing interwall spacing, reaches its maximum value, and then decreases.

  4. Surface enhanced fluorescence and imaging with plasmon near-fields in gold corrugated gratings

    NASA Astrophysics Data System (ADS)

    Mandal, Prasanta; Gupta, Prince; Nandi, Amitabha; Ramakrishna, S. Anantha

    2012-01-01

    Surface plasmon-assisted fluorescence and imaging from Rhodamine 6G dye molecules in polymethyl methacrylate (PMMA) thin films deposited on gold-coated corrugated gratings of various periodicities fabricated by laser interference lithography were investigated. The fluorescence enhancement depends significantly on the periodicity of the corrugated gratings for the green light excitation centered at 548 nm with maximum enhancements at 500 and 1000 nm grating periods. A dielectric PMMA spacer layer placed between the fluorophore layer and the metal surface resulted in a further three-fold enhancement of fluorescence. The period dependent enhancement is caused by the efficient coupling of the excitation radiation to the gold gratings due to the resonant excitation of propagating surface plasmons, which assist the excitation of the fluorophores. Fluorescence imaging shows that the emitted signal is stronger from the top of the corrugated grating surface rather than from that of the valleys. It was ascertained, through surface plasmon resonant dispersion measurements and electromagnetic computations, that enhanced absorption of excitation light through propagating plasmon resonances is the prime contributor to the enhanced fluorescence.

  5. Determination of corrugation and friction of Cu(111) toward adsorption and motion of Ne and Xe

    NASA Astrophysics Data System (ADS)

    Zhang, Y. N.; Bortolani, V.; Mistura, G.

    2014-04-01

    The corrugation feature of potential energy surfaces (PESs) for rare-gas (RG) adlayers on metal surfaces has been extensively explored in the positive adsorption energy part. Here, we show that opposite corrugation features may also happen in the negative adsorption energy side for Ne and Xe on Cu(111). While the PES of Ne/Cu(111) is corrugated near the equilibrium adsorption geometry, i.e., Ne prefers the hollow site, the PES of Xe/Cu(111) is anticorrugated, i.e., Xe prefers the atop site. The weak hybridization of RG p and Cu d states is critical for this qualitative difference. Furthermore, the calculated activation energies indicate that Ne may move on Cu(111) at a very low temperature, whereas Xe motion can be activated only above 35 K. We found that the inclusion of the nonlocal van der Waals correction is essential for the correct determination of adsorption and motion energetics for RG adatoms on metals through density functional calculations.

  6. Evaporation characteristics of R22 flowing inside a corrugated tube. [Tubes with indented spiral turbulence promoter

    SciTech Connect

    Hinton, D.L. (Tennessee State Univ., Nashville, TN (United States)); Conklin, J.C.; Vineyard, E.A. (Oak Ridge National Lab., TN (United States))

    1992-01-01

    Because heat exchanger thermal performance has a direct influence on the overall cycle performance of vapor-compression refrigeration machinery, enhanced heat transfer surfaces are of interest to improve the efficiency of heat pumps and air conditioners. As part of a larger program investigating nonazeotropic refrigerant mixtures for replacement of chlorofluorocarbon compounds, we investigated the performance of R22 (chlorodifluoromethane) in conventional smooth tubes and enhanced heat transfer tube geometries as a base case. This paper presents the results of this initial investigation for a smooth tube and a tube with a commonly available enhanced heat transfer surface, called corrugated or spirally indented. We investigated the evaporating heat transfer and pressure drop characteristics in an experimental apparatus consisting of a variable-speed compressor and two sets of counterflow concentric-tube heat exchangers having both smooth and corrugated enhanced tubeside surfaces. The refrigerant circulates inside the central tube and water circulates in the annulus. The measured pressure drop and the heat transfer coefficient for the evaporation of the R22 are presented as a function of heat flux, quality, and mass flux for both heat transfer surfaces. Both the heat transfer coefficient and the pressure drop of the corrugated surface are higher than those of the smooth surface at any given refrigerant condition. The heat transfer enhancement is most notable at low mass qualities.

  7. Five orders of magnitude reduction in energy coupling across corrugated graphene/substrate interfaces.

    PubMed

    Tang, Xiaoduan; Xu, Shen; Zhang, Jingchao; Wang, Xinwei

    2014-02-26

    A normal full-contact graphene/substrate interface has been reported to have a thermal conductance in the order of 10(8) Wm(-2)K(-1). The reported work used a sandwiched structure to probe the interface energy coupling, and the phonon behavior in graphene was significantly altered in an undesirable way. Here, we report an intriguing study of energy coupling across unconstrained graphene/substrate interfaces. Using novel Raman-based dual thermal probing, we directly measured the temperature drop across the few nm gap interface that is subjected to a local heat flow induced by a second laser beam heating. The thermal conductance (Gt) for graphene/Si and graphene/SiO2 interfaces is determined as 183 ± 10 and 266 ± 10 Wm(-2)K(-1). At the graphene/Si interface, Gt is 5 orders of magnitude smaller than that of full interface contact. It reveals the remarkable effect of graphene corrugation on interface energy coupling. The measurement result is elucidated by atomistic modeling of local corrugation and energy exchange. By decoupling of graphene's thermal and mechanical behavior, we obtained the stress-induced Raman shift of graphene at around 0.1 cm(-1) or less, suggesting extremely loose interface mechanical coupling. The interface gap variation is evaluated quantitatively on the basis of corrugation-induced Raman enhancement. The interface gap could change as much as 1.8 nm when the local thermal equilibrium is destroyed. PMID:24476126

  8. Method of Green's function of nonlinear vibration of corrugated shallow shells

    NASA Astrophysics Data System (ADS)

    Yuan, Hong

    2008-06-01

    Based on the dynamic equations of nonlinear large deflection of axisymmetric shallow shells of revolution, the nonlinear free vibration and forced vibration of a corrugated shallow shell under concentrated load acting at the center have been investigated. The nonlinear partial differential equations of shallow shell were reduced to the nonlinear integral-differential equations by using the method of Green’s function. To solve the integral-differential equations, the expansion method was used to obtain Green’s function. Then the integral-differential equations were reduced to the form with a degenerate core by expanding Green’s function as a series of characteristic function. Therefore, the integral-differential equations became nonlinear ordinary differential equations with regard to time. The amplitude-frequency relation, with respect to the natural frequency of the lowest order and the amplitude-frequency response under harmonic force, were obtained by considering single mode vibration. As a numerical example, nonlinear free and forced vibration phenomena of shallow spherical shells with sinusoidal corrugation were studied. The obtained solutions are available for reference to the design of corrugated shells.

  9. Aerodynamic heating to corrugation stiffened structures in thick turbulent boundary layers

    NASA Technical Reports Server (NTRS)

    Brandon, H. J.; Masek, R. V.; Dunavant, J. C.

    1975-01-01

    The results of an experimental program to evaluate heat transfer and pressure distributions on corrugation roughened flat plates in thick turbulent boundary layers are presented. The experimental program consisted of tests in the tunnel wall boundary layers of the Langley Unitary Plan Wind Tunnel (UPWT) and Continuous Flow Hypersonic Tunnel (CFHT) at freestream Mach numbers of 2.5, 3.5, 4.5, and 10.3. Tests in the UPWT were conducted at a freestream Reynolds number/m of 10,800,000 and in the CFHT, at Reynolds numbers/m of 1,300,000 to 5,800,000. The test configurations consisted of 50.8 x 50.8 cm panels with corrugated beads of two different peak amplitudes, 0.61 and 0.29 cm. The angle of the corrugated beads relative to the flow direction was varied between 0 (aligned) and 90 deg (normal). The measured peak and average heat transfer are analyzed and correlated in terms of the bulk boundary layer, internal boundary layer, and geometric parameters.-

  10. Liner and drill pipe assembly

    SciTech Connect

    Lindsey, H.E.; Cole, P.W.

    1990-02-06

    This patent describes a method of cementing a linear in a well bore. It comprises: making up sections of pipe to form a liner disposed in a well bore to a desired length of liner, supporting the desired length of liner at the earth's surface while making up sections of drill pipe to form a desired string of drill pip co-axially disposed within the desired length of liner where the desired string of drill pipe has a polished mandrel and a sealing bore receptacle at its lower end when the polished mandrel is in position for sealing reception in the sealing bore receptacle, attaching a setting tool assembly to the desired string of drill pipe and attaching a liner hanger assembly with liner hanger slips to the desired length of liner; releasing the liner at the earth's surface and making up a supporting string of drill pipe attached to the setting tool assembly for lowering the co-axially disposed (telescoped) desired length of liner and string of drill pipe through the well bore hanging the liner in the well bore with liner hanger slips; pumping a volume of cement slurry through the supporting string of drill pipe; and upon the trailing end of the volume of cement slurry reaching the lower end of the desired string of drill pipe, opening the interior of the desired string of drill pipe to the interior of the liner at a location above the sealing bore receptacle.

  11. Cryogenic Heat Pipe Experiment (CRYOHP)

    NASA Astrophysics Data System (ADS)

    McIntosh, Roy

    The objective of the CRYOHP experiment is to conduct a shuttle experiment that demonstrates the reliable operation of two oxygen heat pipes in microgravity. The experiment will perform the following tasks: (1) demonstrate startup of the pipes from the supercritical state; (2) measure the heat transport capacity of the pipes; (3) measure evaporator and condenser film coefficients; and (4) work shuttle safety issues. The approach for the experiment is as follows: (1) fly two axially grooved oxygen heat pipes attached to mechanical stirling cycle tactical coolers; (2) integrate experiment in hitch-hiker canister; and (3) fly on shuttle and control from ground.

  12. 14 CFR 25.1123 - Exhaust piping.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... § 25.1123 Exhaust piping. For powerplant and...apply: (a) Exhaust piping must be heat and corrosion...have provisions to prevent failure due to expansion by operating temperatures. (b) Piping must be supported to...

  13. 14 CFR 27.1123 - Exhaust piping.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...System § 27.1123 Exhaust piping. (a) Exhaust piping must be heat and corrosion resistant...must have provisions to prevent failure due to expansion by operating temperatures. (b) Exhaust piping must be supported to...

  14. 14 CFR 29.1123 - Exhaust piping.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...System § 29.1123 Exhaust piping. (a) Exhaust piping must be heat and corrosion resistant...must have provisions to prevent failure due to expansion by operating temperatures. (b) Exhaust piping must be supported to...

  15. 14 CFR 29.1123 - Exhaust piping.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...System § 29.1123 Exhaust piping. (a) Exhaust piping must be heat and corrosion resistant...must have provisions to prevent failure due to expansion by operating temperatures. (b) Exhaust piping must be supported to...

  16. 14 CFR 25.1123 - Exhaust piping.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... § 25.1123 Exhaust piping. For powerplant and...apply: (a) Exhaust piping must be heat and corrosion...have provisions to prevent failure due to expansion by operating temperatures. (b) Piping must be supported to...

  17. 14 CFR 27.1123 - Exhaust piping.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...System § 27.1123 Exhaust piping. (a) Exhaust piping must be heat and corrosion resistant...must have provisions to prevent failure due to expansion by operating temperatures. (b) Exhaust piping must be supported to...

  18. 14 CFR 29.1123 - Exhaust piping.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...System § 29.1123 Exhaust piping. (a) Exhaust piping must be heat and corrosion resistant...must have provisions to prevent failure due to expansion by operating temperatures. (b) Exhaust piping must be supported to...

  19. 14 CFR 27.1123 - Exhaust piping.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...System § 27.1123 Exhaust piping. (a) Exhaust piping must be heat and corrosion resistant...must have provisions to prevent failure due to expansion by operating temperatures. (b) Exhaust piping must be supported to...

  20. 14 CFR 25.1123 - Exhaust piping.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... § 25.1123 Exhaust piping. For powerplant and...apply: (a) Exhaust piping must be heat and corrosion...have provisions to prevent failure due to expansion by operating temperatures. (b) Piping must be supported to...

  1. Rehabilitating underground pipes

    SciTech Connect

    Sorrell, P. [Insituform Technologies, Inc., Memphis, TN (United States)

    1995-06-05

    Nearly 500,000 miles of industrial pipeline in the US are almost three times older than their expected usefulness. And aging pipes that are improperly maintained can cause a variety of environmental problems. It is essential for facilities to have a system of planned maintenance procedures to prevent structural failures related to inflow/infiltration and exfiltration. Trenchless repair methods, often referred to as pipeline rehabilitation, require the plant engineer to consider a range of activities, including demand projection, system performance assessment, investigation, evaluation of defects and deficiencies, remedial options, and implementation. Two methods of pipeline rehabilitation, slip lining and cured-in-place, are described.

  2. Heat Pipe Thermal Conditioning Panel

    NASA Technical Reports Server (NTRS)

    Saaski, E. W.

    1973-01-01

    The development, fabrication, and evaluation of heat pipe thermal conditioning panels are discussed. The panels were designed and fabricated to be compatible with several planned NASA space vehicles, in terms of panel size, capacity, temperature gradients, and integration with various heat exchangers and electronic components. It was satisfactorily demonstrated that the heat pipe thermal conditioning panel meets the thermal efficiency and heat transport requirements.

  3. Alternate high capacity heat pipe

    NASA Technical Reports Server (NTRS)

    Voss, F. E.

    1986-01-01

    The performance predictions for a fifty foot heat pipe (4 foot evaporator - 46 foot condensor) are discussed. These performance predictions are supported by experimental data for a four foot heat pipe. Both heat pipes have evaporators with axial groove wick structures and condensers with powder metal external artery wick structures. The predicted performance of a rectangular axial groove/external artery heat pipe operating in space is given. Heat transport versus groove width is plotted for 100, 200 and 300 grooves in the evaporator. The curves show that maximum power is achieved for groove widths from 0.040 to 0.053 as the number of grooves varies from 300 to 100. The corresponding range of maximum power is 3150 to 2400 watts. The relationships between groove width and heat pipe evaporate diameter for 100, 200 and 300 grooves in the evaporator are given. A four foot heat pipe having a three foot condenser and one foot evaporator was built and tested. The evaporator wick structure used axial grooves with rectangular cross sections, and the condenser wick structure used powder metal with an external artery configuration. Fabrication drawings are enclosed. The predicted and measured performance for this heat pipe is shown. The agreement between predicted and measured performance is good and therefore substantiates the predicted performance for a fifty foot heat pipe.

  4. Composite material heat pipe radiator

    Microsoft Academic Search

    Nelson J. Gernert; David B. Sarraf; Richard J. Guenther

    1996-01-01

    Organic matrix composite material is recognized for its significant strength to weight ratio when compared to metal and consequently was investigated for reducing the mass of heat pipes for future space missions. The particular heat pipe that was constructed and tested was made from an organic matrix composite material applied to a linear of titanium tubing spun to foil thickness

  5. Building a Copper Pipe "Xylophone."

    ERIC Educational Resources Information Center

    Lapp, David R.

    2003-01-01

    Explains how to use the equation for frequency of vibration of a transversely oscillating bar or pipe with both ends free to vibrate to build a simple and inexpensive xylophone from a 3-meter section of copper pipe. The instrument produces a full major scale and can be used to investigate various musical intervals. (Author/NB)

  6. Automatic Piping System in Ship

    Microsoft Academic Search

    Ubald Nienhuis

    One of the most complicated and time-consuming process in ship production is to determine the optimum route of piping. The automatic system to generate optimum collision free routes for pipes is presented in this paper. In the past, research has been primarily focused on the use of only deterministic or only nondeterministic optimization techniques to find the optimal route. In

  7. Demonstrating Sound Impulses in Pipes.

    ERIC Educational Resources Information Center

    Raymer, M. G.; Micklavzina, Stan

    1995-01-01

    Describes a simple, direct method to demonstrate the effects of the boundary conditions on sound impulse reflections in pipes. A graphical display of the results can be made using a pipe, cork, small hammer, microphone, and fast recording electronics. Explains the principles involved. (LZ)

  8. High temperature loop heat pipes

    SciTech Connect

    Anderson, W.G.; Bland, J.J. [Thermacore, Inc., Lancaster, PA (United States); Fershtater, Y.; Goncharov, K.A.; Nikitkin, M. [TAIS, Inc., Moscow (Russian Federation); Juhasz, A. [NASA Lewis Research Center, Cleveland, OH (United States)

    1995-12-31

    Advantages of loop heat pipes over conventional heat pipes include self-priming during start-up, improved tolerance for noncondensible gas, and ability for ground testing in any orientation. The applications for high temperature, alkali-metal working fluid loop heat pipes include space radiators, and bimodal systems. A high temperature loop heat pipe was fabricated and tested at 850 K, using cesium as the working fluid. Previous loop heat pipes were tested with ambient temperature working fluids at temperatures below about 450 K. The loop heat pipe had a titanium envelope, and a titanium aluminide wick. The maximum cesium loop heat pipe power was only about 600 watts, which was lower the predicted 1,000 W power. The power limitation may be due to a wettability problem with the cesium not completely wetting the titanium aluminide wick. This would reduce the pumping capability of the wick, and the maximum power that the heat pipe could carry. This problem could be solved by using a refractory metal powder wick, since the alkali metals are known to wet refractory metal wicks.

  9. Generator cooling using heat pipes

    Microsoft Academic Search

    Bert de LEEUW; Harry Hagens; Brand van den S; Mart Grooten; FLA Ganzevles; Geld van der CWM; Kemenade van HP

    2006-01-01

    This paper presents the study of a heat pipe- equipped heat exchanger with two filling ratios of R134a 19 % and 59 %, respectively. The airflow rate varies from 0.4 to 2.0 kg\\/ s. The temperatures at the evaporator side of the heat pipe vary from 40 to 70 °C and at the condenser part from 20 to 50 °C.

  10. Methods of jointing ceramic pipes

    Microsoft Academic Search

    I. I. Arkhipov; Z. O. Nemchenok

    1975-01-01

    In Czechoslovakia the ceramic pipes are jointed with the help of rubber sealing rings. The rings have a reinforced core and two internal flaps. In the cuff of the ring a steel reinforcement is pressed which hinders its deformation during mounting. The ring has a conical shape and when installed in the neck of a pipe, it clamps by itself.

  11. Measuring flow in a pipe

    SciTech Connect

    Hunt, A.

    1989-08-15

    This patent describes a full bore, multi-phase fluid flowmeter having no internal obstructions. It comprises: a first section of pipe with a first diameter; a second section of pipe with a second diameter less than the first diameter; a third section of pipe intermediate and connecting the first and second pipe sections and having a smoothly and gradually changing diameter from the first diameter to the second diameter; a first pressure sensor positioned in the neighborhood of the start of the change of diameter of the third section of pipe from the first diameter to the second diameter; a second pressure sensor in the first section of pipe spaced in one direction from the first pressure sensor; and a third pressure sensor spaced in the other direction from the first pressure sensor. The density of the fluid flowing through the pipe obtained from a differential pressure measurement made between the first and second pressure sensors is combined with the flow rate of the fluid flowing through the pipe sections obtained from the density value and a second differential pressure measurement made between the first and third pressure sensors to obtain a multi-phase fluid flow determination compensated for phase slippage and friction pressure losses.

  12. Heat pipe radiators for space

    Microsoft Academic Search

    J. P. Sellers

    1976-01-01

    Analysis of the data heat pipe radiator systems tested in both vacuum and ambient environments was continued. The systems included (1) a feasibility VCHP header heat-pipe panel, (2) the same panel reworked to eliminate the VCHP feature and referred to as the feasibility fluid header panel, and (3) an optimized flight-weight fluid header panel termed the 'prototype.' A description of

  13. Heat pipe technology quarterly literature review. Volume 1, Number 3

    Microsoft Academic Search

    R. Srinivasan; R. W. Gonzales

    1983-01-01

    A bibliography containing 110 citations is presented. The citations are arranged in five sections on general information on heat pipes, heat pipe applications, heat pipe theory, heat pipe design, development, and fabrication, and heat pipe testing and operation.

  14. Vapor spill pipe monitor

    DOEpatents

    Bianchini, G.M.; McRae, T.G.

    1983-06-23

    The invention is a method and apparatus for continually monitoring the composition of liquefied natural gas flowing from a spill pipe during a spill test by continually removing a sample of the LNG by means of a probe, gasifying the LNG in the probe, and sending the vaporized LNG to a remote ir gas detector for analysis. The probe comprises three spaced concentric tubes surrounded by a water jacket which communicates with a flow channel defined between the inner and middle, and middle and outer tubes. The inner tube is connected to a pump for providing suction, and the probe is positioned in the LNG flow below the spill pipe with the tip oriented partly downward so that LNG is continuously drawn into the inner tube through a small orifice. The probe is made of a high thermal conductivity metal. Hot water is flowed through the water jacket and through the flow channel between the three tubes to provide the necessary heat transfer to flash vaporize the LNG passing through the inner channel of the probe. The gasified LNG is transported through a connected hose or tubing extending from the probe to a remote ir sensor which measures the gas composition.

  15. Vapor spill pipe monitor

    NASA Astrophysics Data System (ADS)

    Bianchini, G. M.; McRae, T. G.

    1983-06-01

    The invention is a method and apparatus for continually monitoring the composition of liquefied natural gas flowing from a spill pipe during a spill test by continually removing a sample of the LNG by means of a probe, gasifying the LNG in the probe, and sending the vaporized LNG to a remote IR gas detector for analysis. The probe comprises three spaced concentric tubes surrounded by a water jacket which communicates with a flow channel defined between the inner and middle, and middle and outer tubes. The inner tube is connected to a pump for providing suction, and the probe is positioned in the LNG flow below the spill pipe with the tip oriented partly downward so that LNG is continuously drawn into the inner tube through a small orifice. The probe is made of a high thermal conductivity metal. Hot water is flowed through the water jacket and through the flow channel between the three tubes to provide the necessary heat transfer to flash vaporize the LNG passing through the inner channel of the probe. The gasified LNG is transported through a connected hose or tubing extending from the probe to a remote IR sensor which measures the gas composition.

  16. Flexible ultrasonic pipe inspection apparatus

    DOEpatents

    Jenkins, Charles F. (Aiken, SC); Howard, Boyd D. (Augusta, GA)

    1998-01-01

    A flexible, modular ultrasonic pipe inspection apparatus, comprising a flexible, hollow shaft that carries a plurality of modules, including at least one rotatable ultrasonic transducer, a motor/gear unit, and a position/signal encoder. The modules are connected by flexible knuckle joints that allow each module of the apparatus to change its relative orientation with respect to a neighboring module, while the shaft protects electrical wiring from kinking or buckling while the apparatus moves around a tight corner. The apparatus is moved through a pipe by any suitable means, including a tether or drawstring attached to the nose or tail, differential hydraulic pressure, or a pipe pig. The rotational speed of the ultrasonic transducer and the forward velocity of the apparatus are coordinated so that the beam sweeps out the entire interior surface of the pipe, enabling the operator to accurately assess the condition of the pipe wall and determine whether or not leak-prone corrosion damage is present.

  17. Promethus Hot Leg Piping Concept

    SciTech Connect

    AM Girbik; PA Dilorenzo

    2006-01-24

    The Naval Reactors Prime Contractor Team (NRPCT) recommended the development of a gas cooled reactor directly coupled to a Brayton energy conversion system as the Space Nuclear Power Plant (SNPP) for NASA's Project Prometheus. The section of piping between the reactor outlet and turbine inlet, designated as the hot leg piping, required unique design features to allow the use of a nickel superalloy rather than a refractory metal as the pressure boundary. The NRPCT evaluated a variety of hot leg piping concepts for performance relative to SNPP system parameters, manufacturability, material considerations, and comparison to past high temperature gas reactor (HTGR) practice. Manufacturability challenges and the impact of pressure drop and turbine entrance temperature reduction on cycle efficiency were discriminators between the piping concepts. This paper summarizes the NRPCT hot leg piping evaluation, presents the concept recommended, and summarizes developmental issues for the recommended concept.

  18. D0 Silicon Upgrade: Upgrade Piping Loads on Cleanroom Roof

    SciTech Connect

    Sakla, Steve; /Fermilab

    1995-08-28

    The proposed piping layout for the DO upgrade will run along the south wall of DAB. The cryogenic service pipe runs above the upper and lower cleanroom roofs and will need to be supported by the roofs beams. Calculations were done to determine the stresses in the I-beams created by the existing and additional loads due to the upgrade. Refer to drawing no. 3823.115-ME-317283 for drawings of the piping layout. Figure 1 shows the 'plan view' portion of this drawing. The weight of the individual lines were calculated in figure 2 assuming a pipe density of O.28 lbm/in{sup 3} for stainless steel (0.12% C) and a fluid density (assuming LN2 at 1 atm) of 0.03 lbm/in{sup 3}. The weights of the corrugated steel flooring, assembly hall feed cans, support beams, and roof hatch were also included in the analysis. These loads are calculated on pgs. 5-6. A floor load of 50 lbf/ft{sup 2} was also added in order to maintain the existing floor load limit in addition to the added piping loads. Measurements of the dimensions of the I-beams determined that the nominal sizes of the beams were W8 x 21 for the lower roof and W14 x 26 for the upper roof. Pipe lengths were determined from the drawing for each of the lines on pgs. 1-2 of the calculations (refer to all piping by line numbers according to figure 2). A total weight was calculated for lines 3-9 along the south wall and lines 1-2 running along the north wall of the lower cleanroom roof. To simplify the calculations these weights were assumed to be evenly distributed on the 5 I-beam supports of the lower cleanroom roof 2.5 feet in from the south wall. The stress analysis was done using FrameMac, a 2-D finite element program for the Macintosh. Beam 3 was not included in the analysis because it is structurally equivalent to beam 1. The program outputted maximum values for shear stress, bending stress, shear force, and moments in each of the beams analyzed. These values were then compared to the allowable stresses as per the specifications and codes stated in the AISC: Manual of Steel Construction. The stresses on the roof beams needed to be determined in a number of different places. The first was in the beam itself which included the flange and web sections. The second place was at the ends of the beams where the flanges were removed to make the perpendicular connections to the other beams on the lower roof. The final point was the framed beam connection which included the bolt analysis. FrameMac calculated stresses only for the beams which included the sections where the flanges were removed to make the end connections. To analyze the connections, the allowable bending and shear stresses were solved for allowable shear and moments. This was done because FrameMac does not have the capability to analyze the dimensions for the bolts and angles used in the connections were known and the program outputted values for reaction forces and moments at the ends of the beams. Multiplying the allowable shear stress for the bolts and angle connections by their respective areas gave the allowable shear force. The allowable moment for the angle connection was calculated by multiplying the section modulus of the angle by the allowable bending stress. These allowable loads are calculated on pgs. 7-8. The allowable and maximum calculated stresses by FrameMac are summarized in a table. In conclusion, the cleanroom roofs will be able to safely support the weight of the upgrade cryogenic piping, feed cans, corrugated flooring and a 50 lbf/ft{sup 2} floor load with the addition of diagonal braces at the ends of beams 1,2,3,4, and 8. The location and size of these diagonal braces are shown in fig. 4. Also, the piping supports and feed cans will all need to be placed directly above the I-beam supports. These supports will consist of unistrut structures that will be detailed and specified separate to this analysis. The output and input data from FrameMac and the drawings used in the analysis follow the calculation pages.

  19. Prediction of heat transfer coefficients and friction factors for evaporation of R-134a flowing inside corrugated tubes

    NASA Astrophysics Data System (ADS)

    Laohalertdecha, S.; Aroonrat, K.; Dalkilic, A. S.; Mahian, O.; Kaewnai, S.; Wongwises, S.

    2014-04-01

    In this study, experimental and simulation studies of the evaporation heat transfer coefficient and pressure drop of R-134a flowing through corrugated tubes are conducted. The test section is a horizontal counter-flow concentric tube-in-tube heat exchanger 2.0 m in length. A smooth tube and corrugated tubes with inner diameters of 8.7 mm are used as the inner tube. The outer tube is made from a smooth copper tube with an inner diameter of 21.2 mm. The corrugation pitches used in this study are 5.08, 6.35, and 8.46 mm. Similarly, the corrugation depths are 1, 1.25, and 1.5 mm, respectively. The results show that the maximum heat transfer coefficient and pressure drop obtained from the corrugated tube are up to 22 and 19 % higher than those obtained from the smooth tube, respectively. In addition, the average difference of the heat transfer coefficient and pressure drop between the simulation model and experimental data are about 10 and 15 %, respectively.

  20. Non-binding conductor load bearing roller for a gas-insulated transmission line having a corrugated outer conductor

    DOEpatents

    Fischer, William H. (Pittsburgh, PA)

    1984-01-01

    A gas-insulated transmission line includes a corrugated outer conductor, an inner conductor disposed within and insulated from the outer conductor by means of support insulators and an insulating gas, and a non-binding transport device for supporting and permitting movement of the inner conductor/insulating support assembly axially along the corrugated outer conductor without radial displacement and for moving without binding along corrugations of any slope less than vertical. The transport device includes two movable contacts, such as skids or rollers, supported on a common pivot lever, the pivot lever being rotatably disposed about a pivot lever axis, which pivot lever axis is in turn disposed on the periphery of a support insulator or particle trap if one is used. The movable contacts are separated axially a distance equal to the axial distance between the peaks and valleys of the corrugations of the outer conductor and separated radially a distance equal to the radial distance between the peaks and valleys of the corrugations of the outer conductor. The transport device has the pivot lever axis disposed parallel to the motion of travel of the inner conductor/insulating support assembly.

  1. Non-binding conductor load bearing roller for a gas-insulated transmission line having a corrugated outer conductor

    SciTech Connect

    Fischer, W.H.

    1984-04-24

    A gas-insulated transmission line includes a corrugated outer conductor, an inner conductor disposed within and insulated from the outer conductor by means of support insulators and an insulating gas, and a non-binding transport device for supporting and permitting movement of the inner conductor/insulating support assembly axially along the corrugated outer conductor without radial displacement and for moving without binding along corrugations of any slope less than vertical. The transport device includes two movable contacts, such as skids or rollers, supported on a common pivot lever, the pivot lever being rotatably disposed about a pivot lever axis, which pivot lever axis is in turn disposed on the periphery of a support insulator or particle trap if one is used. The movable contacts are separated axially a distance equal to the axial distance between the peaks and valleys of the corrugations of the outer conductor and separated radially a distance equal to the radial distance between the peaks and valleys of the corrugations of the outer conductor. The transport device has the pivot lever axis disposed parallel to the motion of travel of the inner conductor/insulating support assembly. 7 figs.

  2. Heat pipes and their technical applications

    Microsoft Academic Search

    L. L. Vasilev

    1976-01-01

    A general review paper on heat pipes is presented with attention given to principles of operation. Also considered are transfer processes in heat-pipe wicks, the effect of the structural characteristics of a wick on convective transfer of the working fluid, and heat and mass transfer in the wicks of low-temperature heat pipes. Applications of heat pipes in such fields as

  3. Determination of Secondary Encasement Pipe Design Pressure

    SciTech Connect

    TEDESCHI, A.R.

    2000-10-26

    This document published results of iterative calculations for maximum tank farm transfer secondary pipe (encasement) pressure upon failure of the primary pipe. The maximum pressure was calculated from a primary pipe guillotine break. Results show encasement pipeline design or testing pressures can be significantly lower than primary pipe pressure criteria.

  4. 46 CFR 108.447 - Piping.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Piping. 108.447 Section 108.447 Shipping...Fire Extinguishing Systems § 108.447 Piping. (a) Each pipe, valve, and fitting...pounds per square inch). (b) All piping for a CO2 system of nominal size...

  5. Page 1 of 1 Pipe School

    E-print Network

    Huang, Haiying

    Page 1 of 1 Track A Pipe School© Presented by: Terry McArthur; PE, CDT Senior Professional Registration 8:15 Overview of Different Pipe Materials ­ An overview of different pipe materials and their capabilities and limitations for pressure and gravity applications. 9:00 Rigid and Flexible Pipes: A comparison

  6. Hg supply piping simulation Stony Brook University

    E-print Network

    McDonald, Kirk

    Hg supply piping simulation (No MHD) Stony Brook University Yan Zhan Prof. Foluso Ladeinde July 2nd, 2010 #12;Outline · Hg supply piping in Muon Collider · Turbulence models for bend pipe flow · Problems need studying · Arrangements in the near future #12;Outline · Hg supply piping in Muon Collider ­ Hg

  7. Structural Assessment of Small Bore Feeder Piping

    E-print Network

    PIPES AND VALIDATE COMPUTATIONAL METHODS COMPARED TO FULL SCALE TESTS TO FAILURE. THE CLIENT CANDUBACKGROUND Structural Assessment of Small Bore Feeder Piping Kathryn Tang, Janos Mann, Skerdi. Supervisor: A. N. Sinclair CASE ONE CANDU REACTORS HAVE 380+ SMALL BORE FEEDER PIPES. THE PIPES

  8. Performance of a heat pipe solar collector

    Microsoft Academic Search

    K. A. R. Ismail; M. M. Abogderah

    1998-01-01

    This paper presents a comparative study between theoretical predictions and experimental results of a flat-plate solar collector with heat pipes. The theoretical model for the heat pipe solar collector is based upon the method by Duffie and Beckman (1980), modified to use heat pipes for energy transport. The methanol filled heat pipes are self-contained devices whose evaporators are inserted under

  9. Pipe-soil shear interaction stiffness in horizontal directional drilling and pipe bursting

    Microsoft Academic Search

    Abdul Ghafar Chehab; Ian Moore

    2010-01-01

    During horizontal directional drilling and pipe bursting installations, the shear forces between the pipe and the surrounding soil play a major role in the tensile loads and stresses experienced by the pipe. The magnitudes and variations in the shear forces are controlled by the pipe-soil interaction characteristics. This paper discusses the shear interaction between the pipe and the soil during

  10. Hydrological connectivity of soil pipes

    NASA Astrophysics Data System (ADS)

    Holden, J.

    2003-04-01

    Natural soil pipes are common in many parts of the world and particularly in blanket peat uplands yet there are problems in finding and defining soil pipe networks which are often located deep within the peat. Pipeflow can contribute a large proportion of runoff to the river systems in these upland environments and may significantly influence catchment sediment and solute yield. Ground penetrating radar (GPR) technology has recently been developed for non-destructive identification and mapping of soil pipes in peat catchments. While GPR can identify subsurface cavities, it cannot alone determine hydrological connectivity between one cavity and another. This poster presents results from an experiment to test the ability of GPR to establish hydrological connectivity between pipes through use of a tracer solution. Tracers such as sodium chloride were injected at a constant rate into an open pipe cavity. The GPR was moved across the test area downslope. The resultant radargrams were analysed and significantly increased reflectance was observed from a selection of cavities downslope. It was thus possible to determine hydrological connectivity of soil pipes within a dense pipe network across a hillslope without ground disturbance. In addition, tracers were added to the peat surface upslope of known pipe networks. It was possible to then trace the movement of water across and through the hillslope by using GPR to establish the connectivity of a range of flowpaths. Often pipe networks were supplied with water from overland flow entering through cracks and openings where the soil pipe was near the peat surface. Downslope, pipeflow contributed not only directly to streamflow but also to overland flow and near-surface throughflow on the hillslope. The same water that was within a pipe network at four metres depth could become near-surface throughflow outside of the pipe network a few metres down slope. These data allow the first three-dimensional picture of subsurface hydrological pathways to be developed for blanket peat catchments. The improved understanding of flowpath connectivity will be important for understanding solutional and particulate denudation and hydrological and geomorphological model development.

  11. Variable conductance heat pipe technology

    NASA Technical Reports Server (NTRS)

    Marcus, B. D.; Edwards, D. K.; Anderson, W. T.

    1973-01-01

    Research and development programs in variable conductance heat pipe technology were conducted. The treatment has been comprehensive, involving theoretical and/or experimental studies in hydrostatics, hydrodynamics, heat transfer into and out of the pipe, fluid selection, and materials compatibility, in addition to the principal subject of variable conductance control techniques. Efforts were not limited to analytical work and laboratory experimentation, but extended to the development, fabrication and test of spacecraft hardware, culminating in the successful flight of the Ames Heat Pipe Experiment on the OAO-C spacecraft.

  12. Abrasion protection in process piping

    SciTech Connect

    Accetta, J. [Abresist Corp., Urbana, IN (United States)

    1996-07-01

    Process piping often is subjected to failure from abrasion or a combination of abrasion and corrosion. Abrasion is a complex phenomenon, with many factors involved to varying degrees. Hard, mineral based alumina ceramic and basalt materials are used to provide protection against abrasion in many piping systems. Successful life extension examples are presented from many different industries. Lined piping components require special attention with regard to operating conditions as well as design and engineering considerations. Economic justification involves direct cost comparisons and avoided costs.

  13. Scattering of light from metallic films with a corrugated surface: Magnetic field effects in the Voigt geometry

    NASA Astrophysics Data System (ADS)

    Jacobo-Escobar, J. H.; Cocoletzi, Gregorio H.

    2005-12-01

    We study the scattering of electromagnetic waves from a corrugated surface of a metallic film, which has a flat surface in contact with a semi-infinite superlattice. External magnetic fields are accounted for, in the Voigt configuration, to calculate the scattered field amplitudes up to first order on the corrugation height. Two-zero order minima and two-first order peaks are obtained as a result of the coupling of the incident light with the magnetoplasmons at the corrugated surface. The peaks are associated with the p = +/-1 terms in the expansion of the fields. We find that the splitting of the minima is affected by the external field and the superlattice. In the absence of the superlattice the external field splits the symmetric and antisymmetric film modes, however, the presence of the superlattice closes the gap. The gap also depends on the angle of incidence.

  14. A study of structurally efficient graphite-thermoplastic trapezoidal-corrugation sandwich and semi-sandwich panels

    NASA Technical Reports Server (NTRS)

    Jegley, Dawn C.

    1993-01-01

    The structural efficiency of compression-loaded trapezoidal-corrugation sandwich and semi-sandwich composite panels is studied to determine their weight savings potential. Sandwich panels with two identical face sheets and a trapezoidal corrugated core between them, and semi-sandwich panels with a corrugation attached to a single skin are considered. An optimization code is used to find the minimum weight designs for critical compressive load levels ranging from 3,000 to 24,000 lb/in. Graphite-thermoplastic panels based on the optimal minimum weight designs were fabricated and tested. A finite-element analysis of several test specimens was also conducted. The results of the optimization study, the finite-element analysis, and the experiments are presented.

  15. 3D finite element modeling of the micromachined microphone with corrugated diaphragm

    NASA Astrophysics Data System (ADS)

    Borovkov, Alexei I.; Pyatishev, Evgenij N.; Lurie, Mihail S.; Korshunov, Andrey V.; Akulshin, Y. D.; Sabadash, V. O.; Smolnikov, B. A.

    2001-02-01

    Measurements of acoustic pressure oscillations on curvilinear surface streamlined by a flow, for example, on the wall of wind-tunnel or airfoil is necessary to supply for aeroacoustic appendices. Microphone should have the minimal sizes and feeler set flush-mounted. Such microphones are demanded for creation distributed audio-systems and noise reduction devices in the source. Developed the MEMS-microphone with corrugated diaphragm should have a sharp response, stability to effects of ram airflow and high level pressure. Preliminary simulation of design and technological parameters is necessary for creation of this microphone.

  16. 3D finite element modeling of the micromachined microphone with corrugated diaphragm

    NASA Astrophysics Data System (ADS)

    Borovkov, Alexei I.; Pyatishev, Evgenij N.; Lurie, Mihail S.; Korshunov, Andrey V.; Akulshin, Y. D.; Sabadash, V. O.; Smolnikov, B. A.

    2000-02-01

    Measurements of acoustic pressure oscillations on curvilinear surface streamlined by a flow, for example, on the wall of wind-tunnel or airfoil is necessary to supply for aeroacoustic appendices. Microphone should have the minimal sizes and feeler set flush-mounted. Such microphones are demanded for creation distributed audio-systems and noise reduction devices in the source. Developed the MEMS-microphone with corrugated diaphragm should have a sharp response, stability to effects of ram airflow and high level pressure. Preliminary simulation of design and technological parameters is necessary for creation of this microphone.

  17. Escape beam statistics and dynamical properties for a periodically corrugated waveguide

    NASA Astrophysics Data System (ADS)

    da Costa, Diogo Ricardo; Silva, Mário R.; Leonel, Edson D.

    2014-04-01

    Some escape and dynamical properties for a beam of light inside a corrugated waveguide are discussed by using Fresnel reflectance. The system is described by a mapping and is controlled by a parameter ? defining a transition from integrability (?=0) to non integrability (??0). The phase space is mixed containing periodic islands, chaotic seas and invariant tori. The histogram of escaping orbits is shown to be scaling invariant with respect to ?. The waveguide is immersed in a region with different refractive index. Different optical materials are used to overcame the results.

  18. A multiscale spatial filtering account of the Wertheimer-Benary effect and the corrugated Mondrian.

    PubMed

    Blakeslee, B; McCourt, M E

    2001-09-01

    Blakeslee and McCourt [Blakeslee, B., & McCourt, M.E. (1997). Similar mechanisms underlie simultaneous brightness contrast and grating induction. Vision Research, 37, 2849-2869] demonstrated that a multiscale array of two-dimensional difference-of-Gaussian (DOG) filters provided a simple but powerful model for explaining a number of seemingly complex features of grating induction (GI), while simultaneously encompassing salient features of brightness induction in simultaneous brightness contrast (SBC), brightness assimilation and Hermann Grid stimuli. The DOG model (and isotropic contrast models in general) cannot, however, account for another important group of brightness effects including the White effect [White, M. (1997). A new effect of pattern on perceived lightness. Perception, 8, 413-416] and a variant of SBC [Todorovic, D. (1997). Lightness and junctions. Perception, 26, 379-395]. Blakeslee and McCourt [Blakeslee, B., McCourt, M.E. (1999). A multiscale spatial filtering account of the White effect, simultaneous brightness contrast and grating induction. Vision Research, 39, 4361-4377] developed a modified version of the model, an oriented (ODOG) model, which differed from the DOG model in that the filters were anisotropic and their outputs were pooled nonlinearly. Using this model, they were able to account for both groups of induction effects. The present paper examines two additional sets of brightness illusions that cannot be explained by isotropic contrast models. Psychophysical brightness matching is employed to quantitatively measure the size of the brightness effect for two Wertheimer-Benary stimuli [Benary, W. (1924). Beobachtungen zu einem experiment uber helligkeitskontrast. Psychologische Forschung, 5, 131-142; Todorovic, D. (1997). Lightness and junctions. Perception, 26, 379-395] and for low- and high-contrast versions of corrugated Mondrian stimuli [Adelson, E.H. (1993). Perceptual organization and the jugdement of brightness. Science, 262, 2042-2044; Todorovic, D. (1997). Lightness and junctions. Perception, 26, 379-395]. Brightness matches are obtained on both homogeneous and checkerboard matching backgrounds. The ODOG model qualitatively predicts the appearance of the test patches in the Wertheimer-Benary stimuli and corrugated Mondrian stimuli. In addition, it quantitatively predicts the relative magnitudes of the corrugated Mondrian effects in the various conditions. In general, the psychophysical results and ODOG modeling argue strongly that like SBC, GI, the White effect and Todorovic's SBC demonstration, induced brightness in Wertheimer-Benary stimuli and in the corrugated Mondrian primarily reflects early-stage filtering operations in the visual system. PMID:11483179

  19. Heat-transfer performance of a corrugated-tube thermosiphon. Part 1; Evaporator performance

    SciTech Connect

    Negishi, K. (Tokyo Metropolitan Inst. of Technology (JP)); Kaneko, K. (Univ. of Osaka Prefecture (JP)); Matsuoka, T. (Nissan Motor Co., Ltd. (JP)); Hirashima, M.; Nishikawa, Y.; Taguchi, M. (Takuma Research and Development Co., Ltd. (JP))

    1991-01-01

    Two-phase closed thermosiphons are highly efficient heat-transfer elements with applications in terrestrial heat-transport and heat-recovery systems. In this paper, a corrugated copper tube was used as the container of the thermosiphons and distilled water was used as the working fluid. The influences of the liquid charge ratio and inclination angle on the heat-transfer performance were studied. It was found that the optimum liquid charge ratio to evaporator volume is 40 percent and the maximum performance is obtained at an inclination angle of 30 degrees. A useful formula to calculate the heat-transfer coefficient in the evaporator has been derived.

  20. Superresolution observed from evanescent waves transmitted through nano-corrugated metallic films

    E-print Network

    Ben-Aryeh, Y

    2015-01-01

    Plane EM waves transmitted through nano-corrugated metallic thin films produce evanescent waves which include the information on the nano-structures. The production of the evanescent waves at the metallic surface are analyzed. A microsphere located above the metallic surface collects the evanescent waves which are converted into propagating waves. The equations for the refraction at the boundary of the microsphere and the use of Snell's law for evanescent waves are developed. The magnification of the nano-structure images is explained by a geometric optics description, but the high resolution is related to the evanescent waves properties.

  1. Heat pipe life and processing study

    NASA Technical Reports Server (NTRS)

    Antoniuk, D.; Luedke, E. E.

    1979-01-01

    The merit of adding water to the reflux charge in chemically and solvent cleaned aluminum/slab wick/ammonia heat pipes was evaluated. The effect of gas in the performance of three heat pipe thermal control systems was found significant in simple heat pipes, less significant in a modified simple heat pipe model with a short wickless pipe section. Use of gas data for the worst and best heat pipes of the matrix in a variable conductance heat pipe model showed a 3 C increase in the source temperature at full on condition after 20 and 246 years, respectively.

  2. Heat Pipe Applications in Sorption Refrigerators

    Microsoft Academic Search

    L. L. Vasiliev; A. G. Kulakov

    \\u000a Some sorption refrigeration machines (sorption technologies) developed in Belarus are presented in this paper with emphasises\\u000a on different heat pipes application: conventional heat pipes, heat pipe panels, loop heat pipes, vapour-dynamic thermosyphons,\\u000a etc. Heat pipes are very flexible systems with regards to the effective thermal control. They can easily be implemented inside\\u000a sorption refrigerators and other types of refrigerators [1].

  3. Intermediate Temperature Water Heat Pipe Tests

    NASA Technical Reports Server (NTRS)

    Devarakonda, Angirasa; Xiong, Daxi; Beach, Duane E.

    2004-01-01

    Heat pipes are among the most promising technologies for space radiator systems. Water heat pipes are explored in the intermediate temperature range of 400 to above 500 K. The thermodynamic and thermo-physical properties of water are reviewed in this temperature range. Test Data are reported for a copper-water heat pipe. The heat pipe was tested under different orientations. Water heat pipes show promise in this temperature range.Fabrication and testing issues are being addressed.

  4. Intermediate Temperature Water Heat Pipe Tests

    NASA Technical Reports Server (NTRS)

    Devarakonda, Angirasa; Xiong, Da-Xi; Beach, Duane E.

    2005-01-01

    Heat pipes are among the most promising technologies for space radiator systems. Water heat pipes are explored in the intermediate temperature range of 400 to above 500 K. The thermodynamic and thermo-physical properties of water are reviewed in this temperature range. Test data are reported for a copper-water heat pipe. The heat pipe was tested under different orientations. Water heat pipes show promise in this temperature range. Fabrication and testing issues are being addressed.

  5. Physics of heat pipe rewetting

    NASA Technical Reports Server (NTRS)

    Chan, S. H.

    1994-01-01

    This is the final report which summarizes the research accomplishments under the project entitled 'Physics of Heat Pipe Rewetting' under NASA Grant No. NAG 9-525, Basic, during the period of April 1, 1991 to January 31, 1994. The objective of the research project was to investigate both analytically and experimentally the rewetting characteristics of the heated, grooved plate. The grooved plate is to simulate the inner surface of the vapor channel in monogroove heat pipes for space station design. In such designs, the inner surface of the vapor channel is threaded with monogrooves. When the heat pipe is thermally overloaded, dryout of the monogroove surface occurs. Such a dryout surface should be promptly rewetted to prevent the failure of the heat pipe operation in the thermal radiator of the space station.

  6. Light pipes for LED measurements

    NASA Technical Reports Server (NTRS)

    Floyd, S. R.; Thomas, E. F., Jr.

    1976-01-01

    Light pipe directly couples LED optical output to single detector. Small area detector measures total optical output of diode. Technique eliminates thermal measurement problems and channels optical output to remote detector.

  7. Heat Pipes: An Industrial Application 

    E-print Network

    Murray, F.

    1984-01-01

    This paper reviews the basics of heat pipe exchangers. Included are how they are constructed, how they operate, where they have application, and various aspects of evaluating a potential application. After discussing the technical aspects of heat...

  8. Heat Pipe Thermal Conditioning Panel

    NASA Technical Reports Server (NTRS)

    Saaski, E. W.

    1973-01-01

    The technology involved in designing and fabricating a heat pipe thermal conditioning panel to satisfy a broad range of thermal control system requirements on NASA spacecraft is discussed. The design specifications were developed for a 30 by 30 inch heat pipe panel. The fundamental constraint was a maximum of 15 gradient from source to sink at 300 watts input and a flux density of 2 watts per square inch. The results of the performance tests conducted on the panel are analyzed.

  9. Heat pipe cooled power magnetics

    NASA Technical Reports Server (NTRS)

    Chester, M. S.

    1979-01-01

    A high frequency, high power, low specific weight (0.57 kg/kW) transformer developed for space use was redesigned with heat pipe cooling allowing both a reduction in weight and a lower internal temperature rise. The specific weight of the heat pipe cooled transformer was reduced to 0.4 kg/kW and the highest winding temperature rise was reduced from 40 C to 20 C in spite of 10 watts additional loss. The design loss/weight tradeoff was 18 W/kg. Additionally, allowing the same 40 C winding temperature rise as in the original design, the KVA rating is increased to 4.2 KVA, demonstrating a specific weight of 0.28 kg/kW with the internal loss increased by 50W. This space environment tested heat pipe cooled design performed as well electrically as the original conventional design, thus demonstrating the advantages of heat pipes integrated into a high power, high voltage magnetic. Another heat pipe cooled magnetic, a 3.7 kW, 20A input filter inductor was designed, developed, built, tested, and described. The heat pipe cooled magnetics are designed to be Earth operated in any orientation.

  10. Heat pipe turbine vane cooling

    SciTech Connect

    Langston, L.; Faghri, A. [Connecticut Univ., Storrs, CT (United States). Dept. of Mechanical Engineering

    1995-12-31

    The applicability of using heat pipe principles to cool gas turbine vanes is addressed in this beginning program. This innovative concept involves fitting out the vane interior as a heat pipe and extending the vane into an adjacent heat sink, thus transferring the vane incident heat transfer through the heat pipe to heat sink. This design provides an extremely high heat transfer rate and a uniform temperature along the vane due to the internal change of phase of the heat pipe working fluid. Furthermore, this technology can also eliminate hot spots at the vane leading and trailing edges and increase the vane life by preventing thermal fatigue cracking. There is also the possibility of requiring no bleed air from the compressor, and therefore eliminating engine performance losses resulting from the diversion of compressor discharge air. Significant improvement in gas turbine performance can be achieved by using heat pipe technology in place of conventional air cooled vanes. A detailed numerical analysis of a heat pipe vane will be made and an experimental model will be designed in the first year of this new program.

  11. Composite material heat pipe radiator

    NASA Astrophysics Data System (ADS)

    Gernert, Nelson J.; Sarraf, David B.; Guenther, Richard J.; Hurlbert/, Kathryn Miller

    1996-03-01

    Organic matrix composite material is recognized for its significant strength to weight ratio when compared to metal and consequently was investigated for reducing the mass of heat pipes for future space missions. The particular heat pipe that was constructed and tested was made from an organic matrix composite material applied to a linear of titanium tubing spun to foil thickness (0.076 mm). The thin liner transitioned to heavier-walled ends which allowed the tubing to be sealed using conventional welding. More specifically, the heat pipe was 1.14 m long, 24 mm in diameter and had a mass of 0.165 kg. Water was the working fluid. The heat pipe was tested in a Thermacore thermal vacuum chamber under hot and cold wall operating conditions. The heat load dissipated ranged from 10 to 60 watts. Heat pipe operating temperatures varied from 278 K to 403 K. After testing, the heat pipe was delivered to NASA JSC where future thermal vacuum chamber tests are planned.

  12. Design and Fabrication of a Ring-Stiffened Graphite-Epoxy Corrugated Cylindrical Shell

    NASA Technical Reports Server (NTRS)

    Johnson, R., Jr.

    1978-01-01

    Design and fabrication of supplement test panels that represent key portions of the cylinder are described, as are supporting tests of coupons, sample joints, and stiffening ring elements. The cylindrical shell is a ring-stiffened, open corrugation design that uses T300/5208 graphite-epoxy tape as the basic material for the shell wall and stiffening rings. The test cylinder is designed to withstand bending loads producing the relatively low maximum load intensity in the shell wall of 1,576 N/cm. The resulting shell wall weight, including stiffening rings and fasteners, is 0.0156 kg/m. The shell weight achieved in the graphite-epoxy cylinder represents a weight saving of approximately 23 percent, compared to a comparable aluminum shell. A unique fabrication approach was used in which the cylinder wall was built in three flat segments, which were then wrapped to the cylindrical shape. Such an approach, made possible by the flexibility of the thin corrugated wall in a radial direction, proved to be a simple approach to building the test cylinder. Based on tooling and fabrication methods in this program, the projected costs of a production run of 100 units are reported.

  13. Simple Correctors for Elimination of High-Order Modes in Corrugated Waveguide Transmission Lines.

    PubMed

    Kowalski, Elizabeth J; Shapiro, Michael A; Temkin, Richard J

    2014-01-01

    When using overmoded corrugated waveguide transmission lines for high power applications, it is necessary to control the mode content of the system. Ideally, overmoded corrugated transmission lines operate in the fundamental HE11 mode and provide low losses for long distances. Unwanted higher order modes (HOMs), particularly LP11 and HE12, are often excited in the experimental systems due to practical misalignments in the transmission line system. This paper discusses how the unwanted modes propagate along with the fundamental mode in the transmission line system by formulating an equation that relates the center of power offset and angle of propagation of a beam (for the HE11 and LP11 modes) or the waist size and phase front radius of curvature of a beam (for the HE11 and HE12 modes). By introducing two miter bend correctors into the transmission system-miter bends that have slightly angled or ellipsoidal mirrors-the HOMs can be precisely manipulated in the system. This technique can be used to eliminate small quantities of unwanted modes, thereby creating a nearly pure fundamental mode beam with minimal losses. Examples of these applications are calculated and show the theoretical conversion of up to 10% HOM content into the fundamental HE11 mode with minimal losses. PMID:25067859

  14. Electron Beam Energy Chirp Control with a Rectangular Corrugated Structure at the Linac Coherent Light Source

    DOE PAGESBeta

    Zhang, Zhen; Bane, Karl; Ding, Yantao; Huang, Zhirong; Iverson, Richard; Maxwell, Timothy; Stupakov, Gennady; Wang, Lanfa

    2015-01-30

    Electron beam energy chirp is an important parameter that affects the bandwidth and performance of a linac-based, free-electron laser. In this paper we study the wakefields generated by a beam passing between at metallic plates with small corrugations, and then apply such a device as a passive dechirper for the Linac Coherent Light Source (LCLS) energy chirp control with a multi-GeV and femtosecond electron beam. Similar devices have been tested in several places at relatively low energies (#24;100 MeV) and with relatively long bunches (> 1ps). In the parameter regime of the LCLS dechirper, with the corrugation size similar to the gap between the plates, the analytical solutions of the wakefields are no longer applicable, and we resort to a #12;field matching program to obtain the wakes. Based on the numerical calculations, we #12;fit the short-range, longitudinal wakes to simple formulas, valid over a large, useful parameter range. Finally, since the transverse wakefields - both dipole and quadrupole-are strong, we compute and include them in beam dynamics simulations to investigate the error tolerances when this device is introduced in the LCLS.

  15. Electron Beam Energy Chirp Control with a Rectangular Corrugated Structure at the Linac Coherent Light Source

    DOE PAGESBeta

    Zhang, Zhen; Bane, Karl; Ding, Yantao; Huang, Zhirong; Iverson, Richard; Maxwell, Timothy; Stupakov, Gennady; Wang, Lanfa

    2015-01-30

    Electron beam energy chirp is an important parameter that affects the bandwidth and performance of a linac-based, free-electron laser. In this paper we study the wakefields generated by a beam passing between at metallic plates with small corrugations, and then apply such a device as a passive dechirper for the Linac Coherent Light Source (LCLS) energy chirp control with a multi-GeV and femtosecond electron beam. Similar devices have been tested in several places at relatively low energies (#24;100 MeV) and with relatively long bunches (> 1ps). In the parameter regime of the LCLS dechirper, with the corrugation size similar tomore »the gap between the plates, the analytical solutions of the wakefields are no longer applicable, and we resort to a #12;field matching program to obtain the wakes. Based on the numerical calculations, we #12;fit the short-range, longitudinal wakes to simple formulas, valid over a large, useful parameter range. Finally, since the transverse wakefields - both dipole and quadrupole-are strong, we compute and include them in beam dynamics simulations to investigate the error tolerances when this device is introduced in the LCLS.« less

  16. Transmission Loss and Absorption of Corrugated Core Sandwich Panels With Embedded Resonators

    NASA Technical Reports Server (NTRS)

    Allen, Albert R.; Schiller, Noah H.; Zalewski, Bart F.; Rosenthal, Bruce N.

    2014-01-01

    The effect of embedded resonators on the diffuse field sound transmission loss and absorption of composite corrugated core sandwich panels has been evaluated experimentally. Two 1.219 m × 2.438 m panels with embedded resonator arrangements targeting frequencies near 100 Hz were evaluated using non-standard processing of ASTM E90-09 acoustic transmission loss and ASTM C423-09a room absorption test measurements. Each panel is comprised of two composite face sheets sandwiching a corrugated core with a trapezoidal cross section. When inlet openings are introduced in one face sheet, the chambers within the core can be used as embedded acoustic resonators. Changes to the inlet and chamber partition locations allow this type of structure to be tuned for targeted spectrum passive noise control. Because the core chambers are aligned with the plane of the panel, the resonators can be tuned for low frequencies without compromising the sandwich panel construction, which is typically sized to meet static load requirements. Absorption and transmission loss performance improvements attributed to opening the inlets were apparent for some configurations and inconclusive for others.

  17. Study of the effects of corrugated wall structures due to blanket modules around ICRH antennas

    NASA Astrophysics Data System (ADS)

    Dumortier, Pierre; Louche, Fabrice; Messiaen, André; Vervier, Michel

    2014-02-01

    In future fusion reactors, and in ITER, the first wall will be covered by blanket modules. These blanket modules, whose dimensions are of the order of the ICRF wavelengths, together with the clearance gaps between them will constitute a corrugated structure which will interact with the electromagnetic waves launched by ICRF antennas. The conditions in which the grooves constituted by the clearance gaps between the blanket modules can become resonant are studied. Simple analytical models and numerical simulations show that mushroom type structures (with larger gaps at the back than at the front) can bring down the resonance frequencies, which could lead to large voltages in the gaps between the blanket modules and perturb the RF properties of the antenna if they are in the ICRF operating range. The effect on the wave propagation along the wall structure, which is acting as a spatially periodic (toroidally and poloidally) corrugated structure, and hence constitutes a slow wave structure modifying the wall boundary condition, is examined.

  18. Electromagnetic properties of corrugated and smooth waveguides filled with radially inhomogeneous plasma

    SciTech Connect

    Shkvarunets, A.; Kobayashi, S.; Weaver, J.; Carmel, Y.; Rodgers, J.; Antonsen, T.M. Jr.; Granatstein, V.L.; Destler, W.W. [Univ. of Maryland, College Park, MD (United States)

    1996-12-31

    The creation and diagnosis of plasma in high power microwave devices remains one of the primary challenges of plasma microwave electronics. In the present work the authors deal with (a) diagnostics techniques for characterization of radially nonuniform plasma columns suitable for use in high power microwave sources and (b) the effects of such plasmas on the electromagnetic properties of finite length, spatially periodic slow wave structures. Experimental studies were performed both for a strong and weak guiding magnetic field. A single Langmuir probe technique cannot be used alone for precise characterization of magnetized plasma columns, especially for measurements of the electron plasma density. However, using a combination of a novel cylindrical resonant cavity technique supported by accurate numerical calculations of the plasma influence on cavity resonances of a long, thin plasma column they were able to characterize pulsed plasma columns. The peak density and the spatial distributions of the plasma was measured as a function of the applied magnetic field and the plasma gun operating conditions. By applying a combined probe-microwave resonator (X-band) technique to plasma-filled, open, corrugated cavities the authors were able to measure in situ for the first time the complete dispersion curve of the TM{sub 01n} modes of a plasma-loaded, finite length, corrugated cavities immersed in guiding magnetic field.

  19. Corrugation of Phase-Separated Lipid Bilayers Supported by Nanoporous Silica Xerogel Surfaces

    SciTech Connect

    Goksu, E I; Nellis, B A; Lin, W; Satcher Jr., J H; Groves, J T; Risbud, S H; Longo, M L

    2008-10-30

    Lipid bilayers supported by substrates with nanometer-scale surface corrugations holds interest in understanding both nanoparticle-membrane interactions and the challenges of constructing models of cell membranes on surfaces with desirable properties, e.g. porosity. Here, we successfully form a two-phase (gel-fluid) lipid bilayer supported by nanoporous silica xerogel. Surface topology, diffusion, and lipid density in comparison to mica-supported lipid bilayers were characterized by AFM, FRAP, FCS, and quantitative fluorescence microscopy, respectively. We found that the two-phase lipid bilayer follows the xerogel surface contours. The corrugation imparted on the lipid bilayer results in a lipid density that is twice that on a flat mica surface. In direct agreement with the doubling of actual bilayer area in a projected area, we find that the lateral diffusion coefficient (D) of lipids on xerogel ({approx}1.7 {micro}m{sup 2}/s) is predictably lower than on mica ({approx}4.1 {micro}m{sup 2}/s) by both FRAP and FCS techniques. Furthermore, the gel-phase domains on xerogel compared to mica were larger and less numerous. Overall, our results suggest the presence of a relatively defect-free continuous two-phase bilayer that penetrates approximately midway into the first layer of {approx}50 nm xerogel beads.

  20. Electron beam energy chirp control with a rectangular corrugated structure at the Linac Coherent Light Source

    NASA Astrophysics Data System (ADS)

    Zhang, Zhen; Bane, Karl; Ding, Yuantao; Huang, Zhirong; Iverson, Richard; Maxwell, Timothy; Stupakov, Gennady; Wang, Lanfa

    2015-01-01

    Electron beam energy chirp is an important parameter that affects the bandwidth and performance of a linac-based, free-electron laser. In this paper we study the wakefields generated by a beam passing between flat metallic plates with small corrugations, and then apply such a device as a passive dechirper for the Linac Coherent Light Source (LCLS) energy chirp control with a multi-GeV and femtosecond electron beam. Similar devices have been tested in several places at relatively low energies (˜100 MeV ) and with relatively long bunches (>1 ps ). In the parameter regime of the LCLS dechirper, with the corrugation size similar to the gap between the plates, the analytical solutions of the wakefields are no longer applicable, and we resort to a field matching program to obtain the wakes. Based on the numerical calculations, we fit the short-range, longitudinal wakes to simple formulas, valid over a large, useful parameter range. Finally, since the transverse wakefields—both dipole and quadrupole—are strong, we compute and include them in beam dynamics simulations to investigate the error tolerances when this device is introduced in the LCLS.

  1. Beam Mode Expansion of Corrugated Conical Horns with Phase Correcting Lens: Application to Radioastronomy Receivers

    NASA Astrophysics Data System (ADS)

    García, E.; de Haro, L.; O'Sullivan, C.; Cahill, G.; López Fernández, J. A.; Tercero, F.; Galocha, B.; Besada, J. L.

    2003-06-01

    A classical radioastronomy receiver is fed with a corrugated horn and an independent lens, both placed in a cryostat to lower the noise temperature. The beam is focused and directed using a combination of elliptical and plane mirrors. This paper proposes modifying the initial feeding system by placing the lens onto the horn aperture, thereby allowing a size reduction of the horn and lens, and a simplification of their mechanical design. The profiled lens is shaped to correct the phase error on the horn aperture. A quasi-optical model of the horn-plus-lens system has been developed using a Beam Mode Expansion (BME). Results using both a hyperbolic-planar lens and a spherical-elliptical lens, as well as results obtained by using Geometrical Optics (GO) with a Kirchoff Huygens integration to get the far-field pattern, have been compared with measurements. As a direct application, a full focusing system for the new 40-m radiotelescope at the “Centro Astronómico de Yebes” is presented for the 22, 30 and 45 GHz bands. This paper has developed a QO model for a corrugated conical horn with a phase-correcting lens.

  2. 46 CFR 154.356 - Cargo emergency jettisoning piping.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...emergency jettisoning piping. 154.356 Section...Construction and Equipment Ship Arrangements § 154...emergency jettisoning piping. Emergency jettisoning piping must: (a) Meet... Cargo Containment...

  3. 46 CFR 154.356 - Cargo emergency jettisoning piping.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...emergency jettisoning piping. 154.356 Section...Construction and Equipment Ship Arrangements § 154...emergency jettisoning piping. Emergency jettisoning piping must: (a) Meet... Cargo Containment...

  4. 46 CFR 154.356 - Cargo emergency jettisoning piping.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...emergency jettisoning piping. 154.356 Section...Construction and Equipment Ship Arrangements § 154...emergency jettisoning piping. Emergency jettisoning piping must: (a) Meet... Cargo Containment...

  5. 46 CFR 154.356 - Cargo emergency jettisoning piping.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...emergency jettisoning piping. 154.356 Section...Construction and Equipment Ship Arrangements § 154...emergency jettisoning piping. Emergency jettisoning piping must: (a) Meet... Cargo Containment...

  6. 46 CFR 154.356 - Cargo emergency jettisoning piping.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...emergency jettisoning piping. 154.356 Section...Construction and Equipment Ship Arrangements § 154...emergency jettisoning piping. Emergency jettisoning piping must: (a) Meet... Cargo Containment...

  7. Leaks in pipe networks

    USGS Publications Warehouse

    Pudar, Ranko S.; Liggett, James A.

    1992-01-01

    Leak detection in water-distribution systems can be accomplished by solving an inverse problem using measurements of pressure and/or flow. The problem is formulated with equivalent orifice areas of possible leaks as the unknowns. Minimization of the difference between measured and calculated heads produces a solution for the areas. The quality of the result depends on number and location of the measurements. A sensitivity matrix is key to deciding where to make measurements. Both location and magnitude of leaks are sensitive to the quantity and quality of pressure measurements and to how well the pipe friction parameters are known. The overdetermined problem (more measurements than suspected leaks) gives the best results, but some information can be derived from the underdetermined problem. The variance of leak areas, based on the quality of system characteristics and pressure data, indicates the likely accuracy of the results. The method will not substitute for more traditional leak surveys but can serve as a guide and supplement.

  8. Piping inspection round robin

    SciTech Connect

    Heasler, P.G.; Doctor, S.R. [Pacific Northwest National Lab., Richland, WA (United States)

    1996-04-01

    The piping inspection round robin was conducted in 1981 at the Pacific Northwest National Laboratory (PNNL) to quantify the capability of ultrasonics for inservice inspection and to address some aspects of reliability for this type of nondestructive evaluation (NDE). The round robin measured the crack detection capabilities of seven field inspection teams who employed procedures that met or exceeded the 1977 edition through the 1978 addenda of the American Society of Mechanical Engineers (ASME) Section 11 Code requirements. Three different types of materials were employed in the study (cast stainless steel, clad ferritic, and wrought stainless steel), and two different types of flaws were implanted into the specimens (intergranular stress corrosion cracks (IGSCCs) and thermal fatigue cracks (TFCs)). When considering near-side inspection, far-side inspection, and false call rate, the overall performance was found to be best in clad ferritic, less effective in wrought stainless steel and the worst in cast stainless steel. Depth sizing performance showed little correlation with the true crack depths.

  9. NEP heat pipe radiators. [Nuclear Electric Propulsion

    NASA Technical Reports Server (NTRS)

    Ernst, D. M.

    1979-01-01

    This paper covers improvements of heat pipe radiators for the thermionic NEP design. Liquid metal heat pipes are suitable as spacecraft radiator elements because of high thermal conductance, low mass and reliability, but the NEP thermionic system design was too large and difficult to fabricate. The current integral collector-radiator design consisting of several layers of thermionic converters, the annular-tangential collector heat pipe, the radiator heat pipe, and the transition zone designed to minimize the temperature difference between the collector heat pipe and radiator heat pipe are described. Finally, the design of micrometeoroid armor protection and the fabrication of the stainless steel annular heat pipe with a tangential arm are discussed, and it is concluded that the heat rejection system for the thermionic NEP system is well advanced, but the collector-radiator heat pipe transition and the 8 to 10 m radiator heat pipe with two bends require evaluation.

  10. CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES: Dependence of Conductance of Corrugated Graphene Quantum Dot on Geometrical Features

    Microsoft Academic Search

    Gui-Qin Li; Jing-Kang Deng; Jun Cai

    2009-01-01

    Dependence of conductance of corrugated graphene quantum dot (CGQD) on geometrical features including length, width, connection and edge is investigated by the first principles calculations. The results demonstrate that the conductance of CGQD with different geometrical features is different from each other. The positions and amplitudes of discrete levels in densities of states and transmission coefficients are sensitive to geometrical

  11. The low velocity impact response of sandwich beams with a corrugated core or a Y-frame core

    E-print Network

    Fleck, Norman A.

    of impact response to (i) velocity, over a wider range of velocities than achievable with the drop-weight are needed in ship hull designs that do not employ a back face. Keywords: Drop-weight test, Sandwich beam sandwich beams with corrugated and Y-frame cores have been measured in a drop-weight apparatus at 5 ms-1

  12. Radiative decay effects influence the local electromagnetic response of the monolayer graphene with surface corrugations in terahertz range

    NASA Astrophysics Data System (ADS)

    Firsov, Yu. A.; Firsova, N. E.

    2015-07-01

    We continue the study of surface corrugations influence on the monolayer graphene local electromagnetic response in terahertz range we started earlier. The effects of radiative decay, double-valley structure of charge carriers spectrum in graphene and the "breathing" corrugated surface form induced synthetic electric fields are taken into account. To fulfill this program the generalized nonlinear self-consistent-field equation is obtained. In case of weak external alternating electric field E?ext (t) =E?0 cos ?t for the obtained equation in linear approximation on the external electric field the exact solution is found. It shows that in this case we get local induced current paths depending on the surface form z = h (x , y) . This theoretical result qualitatively explains the corresponding experiments with local current patterns depending on the point by corrugations influence. The induced currents formula was obtained without using fully quantum approach which is necessary for theoretical description of such phenomenon in graphene nanoribbons. Besides the formulae obtained in the present paper could become the basis of the new method of the imaging of surface corrugations form for given experimental picture of local current paths.

  13. Experimental study on laminar flow forced-convection in a channel with upper V-corrugated plate heated by radiation

    Microsoft Academic Search

    Ahmed Hamza H Ali; Yutaka Hanaoka

    2002-01-01

    Experimental study of the effects of the operating parameters on laminar flow forced-convection heat transfer for air flowing in a channel having a V-corrugated upper plate heated by radiation heat flux while the other walls are thermally insulated has been carried out. The parameters studied and their ranges were as follows: flow Reynolds number (Re) ranging from 750 to 2050,

  14. Wet-sand impulse loading of metallic plates and corrugated core sandwich panels J.J. Rimoli a

    E-print Network

    Wadley, Haydn

    Wet-sand impulse loading of metallic plates and corrugated core sandwich panels J.J. Rimoli a , B the mechanical response of edge-clamped sandwich panels subject to the impact of explosively driven wet sand of wet sand placed at different standoff distances. Monolithic plates of the same alloy and mass per unit

  15. Migration of contaminants by gas phase transfer from carton board and corrugated board box secondary packaging into foods

    Microsoft Academic Search

    S. M. Jickells; J. Poulin; K. A. Mountfort; M. Fernàndez-ocaña

    2005-01-01

    The gas phase transfer of substances from carton board (CB) and corrugated box board (CBB) through intervening layers to foods was studied. Substances covering a boiling point range of 252–425°C and a range of polarities were incorporated into CB and CBB secondary packaging. Benzophenone was present in some CB materials. Where it was not already present in CB or CBB

  16. Magnetic refrigeration apparatus with heat pipes

    DOEpatents

    Barclay, John A. (Los Alamos, NM); Prenger, Jr., F. Coyne (Madison, WI)

    1987-01-01

    A magnetic refrigerator operating in the 4 to 20 K range utilizes heat pipes to transfer heat to and from the magnetic material at the appropriate points during the material's movement. In one embodiment circular disks of magnetic material can be interleaved with the ends of the heat pipes. In another embodiment a mass of magnetic material reciprocatingly moves between the end of the heat pipe of pipes that transmits heat from the object of cooling to the magnetic material and the end of the heat pipe or pipes that transmits heat from the magnetic material to a heat sink.

  17. 46 CFR 182.430 - Engine exhaust pipe installation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... § 182.430 Engine exhaust pipe installation. (a) The...come in contact with an exhaust pipe. (b) Exhaust gas must not leak from the piping or any connections...under normal conditions. (d) Pipes used for wet exhaust...

  18. 46 CFR 119.430 - Engine exhaust pipe installation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... § 119.430 Engine exhaust pipe installation. (a) The...come in contact with an exhaust pipe. (b) Exhaust gas must not leak from the piping or any connections...under normal conditions. (d) Pipes used for wet exhaust...

  19. 46 CFR 154.512 - Piping: Thermal isolation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Shipping 5 2011-10-01 2011-10-01 false Piping: Thermal isolation. 154.512 Section 154.512 Shipping ...Cargo and Process Piping Systems § 154.512 Piping: Thermal isolation. Low temperature piping must be thermally...

  20. 46 CFR 154.512 - Piping: Thermal isolation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Shipping 5 2014-10-01 2014-10-01 false Piping: Thermal isolation. 154.512 Section 154.512 Shipping ...Cargo and Process Piping Systems § 154.512 Piping: Thermal isolation. Low temperature piping must be thermally...

  1. 46 CFR 154.512 - Piping: Thermal isolation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Shipping 5 2012-10-01 2012-10-01 false Piping: Thermal isolation. 154.512 Section 154.512 Shipping ...Cargo and Process Piping Systems § 154.512 Piping: Thermal isolation. Low temperature piping must be thermally...

  2. 46 CFR 154.512 - Piping: Thermal isolation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Shipping 5 2013-10-01 2013-10-01 false Piping: Thermal isolation. 154.512 Section 154.512 Shipping ...Cargo and Process Piping Systems § 154.512 Piping: Thermal isolation. Low temperature piping must be thermally...

  3. INTERIOR VIEW WITH LARGE PIPE CASTING MACHINE CASTING A 48' ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW WITH LARGE PIPE CASTING MACHINE CASTING A 48' PIPE. - United States Pipe & Foundry Company Plant, Pipe Casting & Testing Area, 2023 St. Louis Avenue at I-20/59, Bessemer, Jefferson County, AL

  4. INTERIOR VIEW WITH LARGE PIPE CASTING MACHINE EXTRACTING A 48' ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW WITH LARGE PIPE CASTING MACHINE EXTRACTING A 48' PIPE. - United States Pipe & Foundry Company Plant, Pipe Casting & Testing Area, 2023 St. Louis Avenue at I-20/59, Bessemer, Jefferson County, AL

  5. 46 CFR 153.292 - Separation of piping systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...false Separation of piping systems. 153.292 Section...DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID...Design and Equipment Piping Systems and Cargo Handling Equipment...292 Separation of piping systems. Cargo piping...

  6. 46 CFR 153.292 - Separation of piping systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...false Separation of piping systems. 153.292 Section...DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID...Design and Equipment Piping Systems and Cargo Handling Equipment...292 Separation of piping systems. Cargo piping...

  7. 46 CFR 153.292 - Separation of piping systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...false Separation of piping systems. 153.292 Section...DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID...Design and Equipment Piping Systems and Cargo Handling Equipment...292 Separation of piping systems. Cargo piping...

  8. 46 CFR 154.548 - Cargo piping: Flow capacity.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Cargo piping: Flow capacity. 154.548 Section 154...Construction and Equipment Cargo and Process Piping Systems § 154.548 Cargo piping: Flow capacity. Piping with an excess...

  9. 46 CFR 154.548 - Cargo piping: Flow capacity.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Cargo piping: Flow capacity. 154.548 Section 154...Construction and Equipment Cargo and Process Piping Systems § 154.548 Cargo piping: Flow capacity. Piping with an excess...

  10. 46 CFR 119.720 - Nonmetallic piping materials.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Nonmetallic piping materials. 119.720 Section 119.720...THAN 49 PASSENGERS MACHINERY INSTALLATION Piping Systems § 119.720 Nonmetallic piping materials. Nonmetallic piping...

  11. 46 CFR 119.720 - Nonmetallic piping materials.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Nonmetallic piping materials. 119.720 Section 119.720...THAN 49 PASSENGERS MACHINERY INSTALLATION Piping Systems § 119.720 Nonmetallic piping materials. Nonmetallic piping...

  12. 46 CFR 119.720 - Nonmetallic piping materials.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Nonmetallic piping materials. 119.720 Section 119.720...THAN 49 PASSENGERS MACHINERY INSTALLATION Piping Systems § 119.720 Nonmetallic piping materials. Nonmetallic piping...

  13. 46 CFR 154.548 - Cargo piping: Flow capacity.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Cargo piping: Flow capacity. 154.548 Section 154...Construction and Equipment Cargo and Process Piping Systems § 154.548 Cargo piping: Flow capacity. Piping with an excess...

  14. 46 CFR 154.512 - Piping: Thermal isolation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Shipping 5 2010-10-01 2010-10-01 false Piping: Thermal isolation. 154.512 Section 154.512 Shipping ...Cargo and Process Piping Systems § 154.512 Piping: Thermal isolation. Low temperature piping must be thermally...

  15. 46 CFR 116.970 - Protection against hot piping.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 2013-10-01 2013-10-01 false Protection against hot piping. 116.970 Section 116.970 Shipping COAST...ARRANGEMENT Rails and Guards § 116.970 Protection against hot piping. Piping, including valves, pipe fittings and...

  16. 46 CFR 116.970 - Protection against hot piping.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 2010-10-01 2010-10-01 false Protection against hot piping. 116.970 Section 116.970 Shipping COAST...ARRANGEMENT Rails and Guards § 116.970 Protection against hot piping. Piping, including valves, pipe fittings and...

  17. 46 CFR 116.970 - Protection against hot piping.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 2014-10-01 2014-10-01 false Protection against hot piping. 116.970 Section 116.970 Shipping COAST...ARRANGEMENT Rails and Guards § 116.970 Protection against hot piping. Piping, including valves, pipe fittings and...

  18. 46 CFR 177.970 - Protection against hot piping.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 2011-10-01 2011-10-01 false Protection against hot piping. 177.970 Section 177.970 Shipping COAST...ARRANGEMENT Rails and Guards § 177.970 Protection against hot piping. Piping, including valves, pipe fittings and...

  19. 46 CFR 177.970 - Protection against hot piping.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 2012-10-01 2012-10-01 false Protection against hot piping. 177.970 Section 177.970 Shipping COAST...ARRANGEMENT Rails and Guards § 177.970 Protection against hot piping. Piping, including valves, pipe fittings and...

  20. 46 CFR 177.970 - Protection against hot piping.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 2010-10-01 2010-10-01 false Protection against hot piping. 177.970 Section 177.970 Shipping COAST...ARRANGEMENT Rails and Guards § 177.970 Protection against hot piping. Piping, including valves, pipe fittings and...

  1. 46 CFR 116.970 - Protection against hot piping.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 2012-10-01 2012-10-01 false Protection against hot piping. 116.970 Section 116.970 Shipping COAST...ARRANGEMENT Rails and Guards § 116.970 Protection against hot piping. Piping, including valves, pipe fittings and...

  2. 46 CFR 116.970 - Protection against hot piping.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 2011-10-01 2011-10-01 false Protection against hot piping. 116.970 Section 116.970 Shipping COAST...ARRANGEMENT Rails and Guards § 116.970 Protection against hot piping. Piping, including valves, pipe fittings and...

  3. 46 CFR 177.970 - Protection against hot piping.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 2014-10-01 2014-10-01 false Protection against hot piping. 177.970 Section 177.970 Shipping COAST...ARRANGEMENT Rails and Guards § 177.970 Protection against hot piping. Piping, including valves, pipe fittings and...

  4. 46 CFR 177.970 - Protection against hot piping.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 2013-10-01 2013-10-01 false Protection against hot piping. 177.970 Section 177.970 Shipping COAST...ARRANGEMENT Rails and Guards § 177.970 Protection against hot piping. Piping, including valves, pipe fittings and...

  5. Centrally activated pipe snubbing system

    DOEpatents

    Cawley, William E. (Richland, WA)

    1985-01-01

    An electromechanical pipe snubbing system and an electromechanical pipe snubber. In the system, each pipe snubber, in a set of pipe snubbers, has an electromechanical mechanism to lock and unlock the snubber. A sensor, such as a seismometer, measures a quantity related to making a snubber locking or unlocking decision. A control device makes an electrical connection between a power supply and each snubber's electromechanical mechanism to simultaneously lock each snubber when the sensor measurement indicates a snubber locking condition. The control device breaks the connection to simultaneously unlock each snubber when the sensor measurement indicates a snubber unlocking condition. In the snubber, one end of the shaft slides within a bore in one end of a housing. The other end of the shaft is rotatably attached to a pipe; the other end of the housing is rotatively attached to a wall. The snubber's electromechanical mechanism locks the slidable end of the shaft to the housing and unlocks that end from the housing. The electromechanical mechanism permits remote testing and lockup status indication for each snubber.

  6. New pipe coating facility provides integral services

    SciTech Connect

    Not Available

    1992-10-01

    This paper reports on a new pipe coating plant in Birmingham which applies versatile fusion bonded epoxy coating on line pipe manufactured by American Steel Pipe. L. B. Foster Co. opened a new pipe coating plant in Birmingham, Ala., in early 1992 in partnership with American Steel Pipe. The new facility is rapidly becoming an integral part of American Steel Pipe's already extensive capability, providing exclusive coating service to American Steel Pipe and its customers. The new pipe coating plant applies Fostercoat fusion bond epoxy coating to American's 8 5/8 - to 24-in pipe. The addition of Foster's extensive coating capability allows American Steel Pipe to offer its customers manufacturing and coating capability at a single location. Fusion bonding provides the most efficient means of combating corrosion and ensuring long-lasting in ground service. That capability begins at American Steel Pipe's two manufacturing plants where steel pipe is fabricated in diameters from 8 5/8- through 24-in. OD with a wall thickness capability of 0.750 in. Length capabilities of run up to 100 ft for API steel line pipe and up to 120 ft for piling and other structural applications.

  7. Heat pipe design handbook, part 1

    NASA Technical Reports Server (NTRS)

    Skrabek, E. A.

    1972-01-01

    The development and characteristics of heat pipes are examined. The subjects discussed are: (1) principles of operation, (2) heat pipe theory, (3) pressure gradient effects, (4) variable conductance, (5) design procedure, and (6) performance limit evaluation.

  8. Highly tapered pentagonal bipyramidal Au microcrystals with high index faceted corrugation: Synthesis and optical properties

    PubMed Central

    Mettela, Gangaiah; Boya, Radha; Singh, Danveer; Kumar, G. V. Pavan; Kulkarni, G. U.

    2013-01-01

    Focusing light at sub-wavelength region opens up interesting applications in optical sensing and imaging beyond the diffraction limit. In the past, tapered Au wires with carved gratings have been employed to achieve nanofocusing. The fabrication process however, is expensive and the obtained wires are polycrystalline with high surface roughness. A chemical synthetic method overcoming these hurdles should be an attractive alternative. Here, we report a method to chemically synthesize Au microcrystals (~10??m) bearing pentagonal bipyramidal morphology with surface corrugations assignable to high index planes. The method is a single step solid state synthesis at a temperature amenable to common substrates. The microcrystals are tapered at both ends forming sharp tips (~55?nm). Individual microcrystals have been used as pick and probe SERS substrates for a dye embedded in a polymer matrix. The unique geometry of the microcrystal also enables light propagation across its length.

  9. Constraints on axion-nucleon coupling constants from measuring the Casimir force between corrugated surfaces

    E-print Network

    V. B. Bezerra; G. L. Klimchitskaya; V. M. Mostepanenko; C. Romero

    2014-08-31

    We obtain stronger laboratory constraints on the coupling constants of axion-like particles to nucleons from measurements of the normal and lateral Casimir forces between sinusoidally corrugated surfaces of a sphere and a plate. For this purpose, the normal and lateral additional force arising in the experimental configurations due to two-axion exchange between protons and neutrons are calculated. Our constraints following from measurements of the normal and lateral Casimir forces are stronger than the laboratory constraints reported so far for masses of axion-like particles larger than 11eV and 8eV, respectively. A comparison between various laboratory constraints on the coupling constants of axion-like particles to nucleons obtained from the magnetometer measurements, Eotvos- and Cavendish-type experiments, and from the Casimir effect is performed over the wide range of masses of axion-like particles from 10^{-10}eV to 20eV.

  10. Energy shift of collective electron excitations in highly corrugated graphitic nanostructures: Experimental and theoretical investigation

    NASA Astrophysics Data System (ADS)

    Sedelnikova, O. V.; Bulusheva, L. G.; Asanov, I. P.; Yushina, I. V.; Okotrub, A. V.

    2014-04-01

    Effect of corrugation of hexagonal carbon network on the collective electron excitations has been studied using optical absorption and X-ray photoelectron spectroscopy in conjunction with density functional theory calculations. Onion-like carbon (OLC) was taken as a material, where graphitic mantle enveloping agglomerates of multi-shell fullerenes is strongly curved. Experiments showed that positions of ? and ? + ? plasmon modes as well as ? ? ?* absorption peak are substantially redshifted for OLC as compared with those of highly ordered pyrolytic graphite and thermally exfoliated graphite consisted of planar sheets. This effect was reproduced in behavior of dielectric functions of rippled graphite models calculated within the random phase approximation. We conclude that the energy of electron excitations in graphitic materials could be precisely tuned by a simple bending of hexagonal network without change of topology. Moreover, our investigation suggests that in such materials optical exciton can transfer energy to plasmon non-radiatively.

  11. Energy shift of collective electron excitations in highly corrugated graphitic nanostructures: Experimental and theoretical investigation

    SciTech Connect

    Sedelnikova, O. V., E-mail: o.sedelnikova@gmail.com; Bulusheva, L. G.; Okotrub, A. V. [Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Science, 3 Acad. Lavrentiev Ave., Novosibirsk 630090 (Russian Federation); Novosibirsk State University, 2 Pirogov Str., Novosibirsk 630090 (Russian Federation); Tomsk State University, 36 Lenina Ave., Tomsk 634050 (Russian Federation); Asanov, I. P. [Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Science, 3 Acad. Lavrentiev Ave., Novosibirsk 630090 (Russian Federation); Novosibirsk State University, 2 Pirogov Str., Novosibirsk 630090 (Russian Federation); Yushina, I. V. [Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Science, 3 Acad. Lavrentiev Ave., Novosibirsk 630090 (Russian Federation)

    2014-04-21

    Effect of corrugation of hexagonal carbon network on the collective electron excitations has been studied using optical absorption and X-ray photoelectron spectroscopy in conjunction with density functional theory calculations. Onion-like carbon (OLC) was taken as a material, where graphitic mantle enveloping agglomerates of multi-shell fullerenes is strongly curved. Experiments showed that positions of ? and ??+?? plasmon modes as well as ? ? ?* absorption peak are substantially redshifted for OLC as compared with those of highly ordered pyrolytic graphite and thermally exfoliated graphite consisted of planar sheets. This effect was reproduced in behavior of dielectric functions of rippled graphite models calculated within the random phase approximation. We conclude that the energy of electron excitations in graphitic materials could be precisely tuned by a simple bending of hexagonal network without change of topology. Moreover, our investigation suggests that in such materials optical exciton can transfer energy to plasmon non-radiatively.

  12. Theory of the corrugation instability of a piston-driven shock wave

    NASA Astrophysics Data System (ADS)

    Bates, J. W.

    2015-01-01

    We analyze the two-dimensional stability of a shock wave driven by a steadily moving corrugated piston in an inviscid fluid with an arbitrary equation of state. For h ?-1 or h >hc , where h is the D'yakov parameter and hc is the Kontorovich limit, we find that small perturbations on the shock front are unstable and grow—at first quadratically and later linearly—with time. Such instabilities are associated with nonequilibrium fluid states and imply a nonunique solution to the hydrodynamic equations. The above criteria are consistent with instability limits observed in shock-tube experiments involving ionizing and dissociating gases and may have important implications for driven shocks in laser-fusion, astrophysical, and/or detonation studies.

  13. Backward displacement of ultrasonic waves reflected from a periodically corrugated interface

    NASA Astrophysics Data System (ADS)

    Teklu, A.; Breazeale, M. A.; Declercq, Nico F.; Hasse, Roger D.; McPherson, Michael S.

    2005-04-01

    Experiments using the schlieren technique to image sound incident on a corrugated, water-brass interface show a backward displacement of the reflected beam at an angle of 22.5°, confirming the observations of Breazeale and Torbett [Appl. Phys. Lett. 29, 456 (1976)]. However, the present theory hypothesizes that this beam displacement results from excitation of a type of leaky surface wave. Further experiments with a sufficiently narrow incident beam reveal a backward displacement also at angles around 44°, resulting from excitation of Rayleigh surface waves, as predicted by the theory of Tamir and Bertoni [J. Acoust. Soc. Am. 61, 1397 (1971)]. Thus, a wide beam gives a backward displacement at 22.5° only. A narrow beam gives a backward displacement also at angles around 44°.

  14. Models of Turbulent Pipe Flow

    NASA Astrophysics Data System (ADS)

    Bourguignon, Jean-Loup

    The physics of turbulent pipe flow was investigated via the use of two models based on simplified versions of the Navier-Stokes equations. The first model was a streamwise-constant projection of these equations, and was used to study the change in mean flow that occurs during transition to turbulence. The second model was based on the analysis of the turbulent pipe flow resolvent, and provided a radial basis for the modal decomposition of turbulent pipe flow. The two models were tested numerically and validated against experimental and numerical data. Analysis of the streamwise-constant model showed that both non-normal and nonlinear effects are required to capture the blunting of the velocity profile, which occurs during pipe flow transition. The model generated flow fields characterized by the presence of high- and low-speed streaks, whose distribution over the cross-section of the pipe was remarkably similar to the one observed in the velocity field near the trailing edge of the puff structures present in pipe flow transition. A modal decomposition of turbulent pipe flow, in the three spatial directions and in time, was performed, and made possible by the significant reduction in data requirements achieved via the use of compressive sampling and model-based radial basis functions. The application and efficiency of compressive sampling in wall-bounded turbulence was demonstrated. Approximately sparse representations of turbulent pipe flow by propagating waves with model-based radial basis functions, were derived. The basis functions, obtained by singular value decomposition of the resolvent, captured the wall-normal coherence of the flow; and provided a link between the propagating waves and the governing equations, allowing for the identification of the dominant mechanisms sustaining the waves, as a function of their streamwise wavenumber. Analysis of the resolvent showed that the long streamwise waves are amplified mainly via non-normality effects, and are also constrained to be tall in the wall-normal direction, which decreases the influence of viscous dissipation. The short streamwise waves were shown to be localized near the critical-layer (defined as the wall-normal location where the convection velocity of the wave equals the local mean velocity), and thus exhibit amplification with a large contribution from criticality. The work in this thesis allows the reconciliation of the well-known results concerning optimal disturbance amplification due to non-normal effects with recent resolvent analyses, which highlighted the importance of criticality effects.

  15. Heat pipe heat exchanger design considerations

    Microsoft Academic Search

    K. T. Feldman; D. C. Lu

    1976-01-01

    Typical heat pipe heat exchangers (HPHX) are described, along with their advantages, uses, and some problems in HPHX design, and a computer HPHX analysis program is discussed with required input data. The computer program is being developed for analysis of heat exchange performance by finned-tube HPHX and thread-puddle-artery heat pipes. Copper-water heat pipes and carbon steel-Dowtherm A heat pipes are

  16. Dynamics of heat-pipe reactors

    NASA Technical Reports Server (NTRS)

    Niederauer, G. F.

    1971-01-01

    A split-core heat pipe reactor, fueled with either U(233)C or U(235)C in a tungsten cermet and cooled by 7-Li-W heat pipes, was examined for the effects of the heat pipes on reactor while trying to safely absorb large reactivity inputs through inherent shutdown mechanisms. Limits on ramp reactivity inputs due to fuel melting temperature and heat pipe wall heat flux were mapped for the reactor in both startup and at-power operating modes.

  17. Thermal Performance of High Temperature Titanium-Water Heat Pipes by Multiple Heat Pipe Manufacturers

    NASA Technical Reports Server (NTRS)

    Sanzi, James L.

    2007-01-01

    Titanium-water heat pipes are being investigated for use in heat rejection systems for lunar and Mars fission surface power systems. Heat pipes provide an efficient and reliable means to transfer heat to a radiator heat rejection system. NASA Glenn Research Center requisitioned nine titanium water heat pipes from three vendors. Each vendor supplied three heat pipes 1.25 cm diameter by 1.1 meter long with each vendor selecting a different wick design. Each of the three heat pipes is slightly different in construction. Additional specifications for the heat pipes included 500 K nominal operating temperature, light weight, and freeze tolerance. The heat pipes were performance tested gravity-aided, in the horizontal position and at elevations against gravity at 450 and 500 K. Performance of the three heat pipes is compared. The heat pipe data will be used to verify models of heat pipe radiators that will be used in future space exploration missions.

  18. Thermal Performance of High Temperature Titanium -- Water Heat Pipes by Multiple Heat Pipe Manufacturers

    NASA Technical Reports Server (NTRS)

    Sanzi, James L.

    2007-01-01

    Titanium - water heat pipes are being investigated for use in heat rejection systems for lunar and Mars fission surface power systems. Heat pipes provide an efficient and reliable means to transfer heat to a radiator heat rejection system. NASA Glenn Research Center requisitioned nine titanium water heat pipes from three vendors. Each vendor supplied three heat pipes 1.25 cm diameter by 1.1 meter long with each vendor selecting a different wick design. Each of the three heat pipes is slightly different in construction. Additional specifications for the heat pipes included 500 K nominal operating temperature, light weight, and freeze tolerance. The heat pipes were performance tested gravity-aided, in the horizontal position and at elevations against gravity at 450 K and 500 K. Performance of the three heat pipes is compared. The heat pipe data will be used to verify models of heat pipe radiators that will be used in future space exploration missions.

  19. 49 CFR 192.59 - Plastic pipe.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 3 2012-10-01 2012-10-01 false Plastic pipe. 192.59 Section 192.59 Transportation...FEDERAL SAFETY STANDARDS Materials § 192.59 Plastic pipe. (a) New plastic pipe is qualified for use under this part...

  20. 49 CFR 192.59 - Plastic pipe.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 3 2013-10-01 2013-10-01 false Plastic pipe. 192.59 Section 192.59 Transportation...FEDERAL SAFETY STANDARDS Materials § 192.59 Plastic pipe. (a) New plastic pipe is qualified for use under this part...

  1. 49 CFR 192.59 - Plastic pipe.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 3 2014-10-01 2014-10-01 false Plastic pipe. 192.59 Section 192.59 Transportation...FEDERAL SAFETY STANDARDS Materials § 192.59 Plastic pipe. (a) New plastic pipe is qualified for use under this part...

  2. FIELD STUDIES OF IMPREGNATED CONCRETE PIPE

    EPA Science Inventory

    The follow-on study (initiated in June 1980) continued to monitor performance of 1,400 ft of impregnated concrete pipe installed in several Texas cities. The performance of concrete pipe has been compared with that of sulfur-impregnated concrete pipe; hydrofluoric acid (HF)-treat...

  3. 49 CFR 192.279 - Copper pipe.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Transportation 3 2014-10-01 2014-10-01 false Copper pipe. 192.279 Section 192.279 Transportation...of Materials Other Than by Welding § 192.279 Copper pipe. Copper pipe may not be threaded except that copper...

  4. 49 CFR 192.279 - Copper pipe.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Transportation 3 2010-10-01 2010-10-01 false Copper pipe. 192.279 Section 192.279 Transportation...of Materials Other Than by Welding § 192.279 Copper pipe. Copper pipe may not be threaded except that copper...

  5. 49 CFR 192.279 - Copper pipe.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Transportation 3 2011-10-01 2011-10-01 false Copper pipe. 192.279 Section 192.279 Transportation...of Materials Other Than by Welding § 192.279 Copper pipe. Copper pipe may not be threaded except that copper...

  6. 49 CFR 192.279 - Copper pipe.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Transportation 3 2013-10-01 2013-10-01 false Copper pipe. 192.279 Section 192.279 Transportation...of Materials Other Than by Welding § 192.279 Copper pipe. Copper pipe may not be threaded except that copper...

  7. 49 CFR 192.279 - Copper pipe.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Transportation 3 2012-10-01 2012-10-01 false Copper pipe. 192.279 Section 192.279 Transportation...of Materials Other Than by Welding § 192.279 Copper pipe. Copper pipe may not be threaded except that copper...

  8. Heat pipe waste heat recovery boilers

    Microsoft Academic Search

    D. A. Littwin; J. McCurley

    1981-01-01

    The use of heat pipes as transport devices in waste heat recovery boilers is examined. Test results show that heat pipes can efficiently extract heat from the hot gas stream and transfer it inside the pressure vessel for the steam generation process. The benefits of incorporating heat pipes into the design of waste heat recovery boilers include a highly compact

  9. Pipe viscometry of foams C. Enzendorfer

    E-print Network

    Valkó, Peter

    Pipe viscometry of foams C. Enzendorfer Institute of Drilling and Production, Mining University This paper describes a method for extracting useful information from small-scale pipe viscometer,and quality was determined in pipes of five diameters. The flow curves showed a marked dependenceon

  10. 46 CFR 76.25-30 - Piping.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Shipping 3 2014-10-01 2014-10-01 false Piping. 76.25-30 Section 76.25-30 Shipping...Automatic Sprinkling System, Details § 76.25-30 Piping. (a) All piping, valves, and fittings of ferrous materials...

  11. Original article Worker piping associated with foraging

    E-print Network

    Paris-Sud XI, Université de

    Original article Worker piping associated with foraging in undisturbed queenright colonies of honey piping, previously reported only in association with colony disturbance or queen- lessness, was seen in undisturbed, queenright colonies. Workers piped by pressing the thorax to the comb, spreading the wings

  12. 46 CFR 76.25-30 - Piping.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Shipping 3 2012-10-01 2012-10-01 false Piping. 76.25-30 Section 76.25-30 Shipping...Automatic Sprinkling System, Details § 76.25-30 Piping. (a) All piping, valves, and fittings of ferrous materials...

  13. 46 CFR 76.25-30 - Piping.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Shipping 3 2013-10-01 2013-10-01 false Piping. 76.25-30 Section 76.25-30 Shipping...Automatic Sprinkling System, Details § 76.25-30 Piping. (a) All piping, valves, and fittings of ferrous materials...

  14. 46 CFR 119.455 - Fuel piping.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Requirements § 119.455 Fuel piping. (a) Materials and workmanship...that: (i) Diesel fuel piping of other materials, such...used; (ii) Diesel fuel piping of aluminum is acceptable...mechanical impact and resistant to failure due to thermal shock....

  15. 46 CFR 119.455 - Fuel piping.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Requirements § 119.455 Fuel piping. (a) Materials and workmanship...that: (i) Diesel fuel piping of other materials, such...used; (ii) Diesel fuel piping of aluminum is acceptable...mechanical impact and resistant to failure due to thermal shock....

  16. 46 CFR 119.455 - Fuel piping.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Requirements § 119.455 Fuel piping. (a) Materials and workmanship...that: (i) Diesel fuel piping of other materials, such...used; (ii) Diesel fuel piping of aluminum is acceptable...mechanical impact and resistant to failure due to thermal shock....

  17. 46 CFR 182.455 - Fuel piping.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Requirements § 182.455 Fuel piping. (a) Materials and workmanship...that: (i) Diesel fuel piping of other materials, such...used; (ii) Diesel fuel piping of aluminum is acceptable...mechanical impact and resistant to failure due to thermal shock....

  18. 46 CFR 182.455 - Fuel piping.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Requirements § 182.455 Fuel piping. (a) Materials and workmanship...that: (i) Diesel fuel piping of other materials, such...used; (ii) Diesel fuel piping of aluminum is acceptable...mechanical impact and resistant to failure due to thermal shock....

  19. 46 CFR 119.455 - Fuel piping.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...lines, including pipe, tube, and hose...as seamless steel pipe or tubing, which...iii) When used, flexible hose must meet the...Tubing connections and fittings must be of nonferrous...suitable tools. Tube ends must be annealed...lines, including pipe, tube, and...

  20. AUTONOMOUS BURIED PIPE DETECTION USING NEURAL NETWORKS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An autonomous pipe detection algorithm using two independent Artificial Neural Networks (ANN) in two dimensional GPR data has been developed. And a pipe orientation estimation method has been discussed. The first neural network, called step-l ANN, was trained with a waveform reflected from a pipe in...

  1. 49 CFR 192.59 - Plastic pipe.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 3 2011-10-01 2011-10-01 false Plastic pipe. 192.59 Section 192.59 Transportation...FEDERAL SAFETY STANDARDS Materials § 192.59 Plastic pipe. (a) New plastic pipe is qualified for use under this part...

  2. 49 CFR 192.59 - Plastic pipe.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 3 2010-10-01 2010-10-01 false Plastic pipe. 192.59 Section 192.59 Transportation...FEDERAL SAFETY STANDARDS Materials § 192.59 Plastic pipe. (a) New plastic pipe is qualified for use under this part...

  3. Heat pipe tests on Space Shuttle flights

    Microsoft Academic Search

    W. Supper; M. Groll

    1985-01-01

    Heap pipes represent light-weight, highly efficient devices for thermal control. For this reason, their utilization is considered in the context of manned space flight missions and future space stations. Extensive ground tests have been conducted in connection with the development of heat pipe designs for space applications. However, the absence of gravity can affect the processes of heat pipe operation,

  4. Heat pipes in space and on earth

    Microsoft Academic Search

    S. Ollendorf

    1978-01-01

    The performance of heat pipes used in the thermal control system of spacecraft such as OAO-III and ATS-6 is discussed, and applications of heat pipes to permafrost stabilization on the Alaska Pipeline and to heat recovery systems are described. Particular attention is given to the ATS-6, launched in 1974, which employs 55 heat pipes to carry solar and internal power

  5. Microstructural characterization of pipe bomb fragments

    Microsoft Academic Search

    Otto Gregory; Jimmie Oxley; James Smith; Michael Platek; Hamouda Ghonem; Evan Bernier; Markus Downey; Christopher Cumminskey

    2010-01-01

    Recovered pipe bomb fragments, exploded under controlled conditions, have been characterized using scanning electron microscopy, optical microscopy and microhardness. Specifically, this paper examines the microstructural changes in plain carbon-steel fragments collected after the controlled explosion of galvanized, schedule 40, continuously welded, steel pipes filled with various smokeless powders. A number of microstructural changes were observed in the recovered pipe fragments:

  6. Ceramic heat pipe heat exchangers

    Microsoft Academic Search

    W. A. Ranken

    1976-01-01

    High-temperature strength, resistance to corrosive atmospheres, and moderate cost combine to make ceramic materials an obvious choice for construction of high-temperature thermal energy recuperator systems. Despite these advantages, ceramic recuperators are steadily being replaced by metallic units at considerable sacrifice in maximum air or fuel preheat temperatures and hence in recovery efficiency. By constructing a recuperator from ceramic heat pipes,

  7. Hot Leg Piping Materials Issues

    Microsoft Academic Search

    V. Munne

    2006-01-01

    With Naval Reactors (NR) approval of the Naval Reactors Prime Contractor Team (NRPCT) recommendation to develop a gas cooled reactor directly coupled to a Brayton power conversion system as the space nuclear power plant (SNPP) for Project Prometheus (References a and b) the reactor outlet piping was recognized to require a design that utilizes internal insulation (Reference c). The initial

  8. Pipe inspection and repair system

    NASA Technical Reports Server (NTRS)

    Schempf, Hagen (Inventor); Mutschler, Edward (Inventor); Chemel, Brian (Inventor); Boehmke, Scott (Inventor); Crowley, William (Inventor)

    2004-01-01

    A multi-module pipe inspection and repair device. The device includes a base module, a camera module, a sensor module, an MFL module, a brush module, a patch set/test module, and a marker module. Each of the modules may be interconnected to construct one of an inspection device, a preparation device, a marking device, and a repair device.

  9. Pipe effect in viscous liquids

    E-print Network

    V. Capano; S. Esposito; G. Salesi

    2008-12-23

    A detailed experimental and theoretical study has been performed about a phenomenon, not previously reported in the literature, occurring in highly viscous liquids: the formation of a definite pipe structure induced by the passage of a heavy body, this structure lasting for quite a long time. A very rich phenomenology (including mechanical, optical and structural effects) associated with the formation of the pipe has been observed in different liquids. Actually, the peculiar dynamical evolution of that structure does not appear as a trivial manifestation of standard relaxation or spurious effects. In particular we have revealed different time scales during the evolution of the pipe and a non-monotonous decreasing of the persistence time with decreasing viscosity (with the appearance of at least two different maxima). A microscopic model consistent with the experimental data, where the pipe behaves as a cylindrical dielectric shell, has been proposed. The general time evolution of the structure has been described in terms of a simple thermodynamical model, predicting several peculiarities effectively observed.

  10. PWR secondary system pipe thinning

    SciTech Connect

    Shor, S.W.W.; Osbourne, M.R. (Bechtel Western Power Corp., San Francisco, CA (USA)); Wilzbach, J.H.; Freid, S.H. (Bechtel Power Corp., Los Angeles, CA (USA))

    1988-01-01

    Nuclear power plants have been experiencing significant thinning of pipe walls from wet steam at least since 1962, when a leak occurred in an extraction line at Dresden Unit 2. Many plants have had valves and piping dow-stream of valves damaged by flashing water. However, it was not until Surry Unit 2 experienced a dramatic pipe rupture in December 1986 at the suction of a feedwater pump that thinning in high energy lnes carrying only liquid water attracted widespread attention, although a similar failure had occurred in a pipe on the discharge side of a heater drain pump at Trojan about 20 months earlier.Seven months after the Surry incident the Nuclear Regulatory Commission issued a bulletin (IEB 87-01) requiring utilities to report their programs to identify and control erosion-corrosion. The NRC also sent out a questionnaire to collect information on the secondary water chemistry of PWRS. Analysis of their responses indicates that not only is erosion-corrosion widespread but that there is need for an easy way to understand its causes in a particular plant, evaluate alternative actions for its correction and arrive at practical, cost-effective programs to control it. This paper suggests how to fill that need in ways that will stop or nearly stop the progress of wall thinning and provide convincing evidence that it has been arrested. Specifically, it identifies water chemistry changes as the most cost-effective way to arrest widespread erosion-corrosion.

  11. Magnetohydrodynamic pipe flow. Part 1

    Microsoft Academic Search

    Richard R. Gold

    1962-01-01

    The solution is obtained to the problem of the steady onedimensional ; flow of an incompressible, viscous, electrically fluid through a circular pipe in ; the presence of an applied (transverse) uniform magnetic field. A no-slip ; condition on the velocity is assumed at the nonconducting wall. The solution is ; exact and thus valid for all values of the

  12. Modeling of pulsating heat pipes

    Microsoft Academic Search

    Richard C. Givler; Mario J. Martinez

    2009-01-01

    This report summarizes the results of a computer model that describes the behavior of pulsating heat pipes (PHP). The purpose of the project was to develop a highly efficient (as compared to the heat transfer capability of solid copper) thermal groundplane (TGP) using silicon carbide (SiC) as the substrate material and water as the working fluid. The objective of this

  13. Fiberscopic Inspection of Pipe Provers

    Microsoft Academic Search

    Iva Williams

    1982-01-01

    American Petroleum Institute (API) standards require the calibration of pipe provers once every five years to establish the known volume. If the prover volume changes during this period, then the calibrated volume and the meter factors obtained will no longer be accurate. Consequently, the actual volumes transferred and the volumes reported as transferred for accounting purposes will be different. Internal

  14. A smooth-walled spline-profile horn as an alternative to the corrugated horn for wide band millimeter-wave applications

    Microsoft Academic Search

    Christophe Granet; Graeme L. James; Russell Bolton; Graham Moorey

    2004-01-01

    At millimeter-wave frequencies, corrugated horns can be difficult and expensive to manufacture. As an alternative we present here the results of a theoretical and measurement study of a smooth-walled spline-profile horn for specific application in the 80-120 GHz band. While about 50% longer than its corrugated counterpart, the smooth-walled horn is shown to give improved performance across the band as

  15. Arterial and grooved cryogenic heat pipes.

    NASA Technical Reports Server (NTRS)

    Brennan, P.; Trimmer, D.; Sherman, A.; Cygnarowicz, T.

    1971-01-01

    Tests were conducted on two cryogenic heat pipes using nitrogen as the working fluid. Both pipes are 1.27 cm in diameter. The first pipe is 141 cm long and uses longitudinal grooves in the aluminum wall as the wick structure. The second pipe is 91 cm long and has an arterial wick adjacent to the wall. In addition, circumferential screw threads are machined along the entire length of the inside pipe wall. Both heat pipes primed with no difficulty in the horizontal position. Start-up after burn-out was obtained repeatedly. However, more testing is required to determine whether the artery pipe is as reliable as the grooved pipe with respect to priming. Once primed, the artery heat pipe is much less sensitive to elevation than the grooved design and, consequently, offers a significant advantage with respect to ground testing. Heat-transfer characteristics of the two pipes were comparable, with both pipes achieving the initial goal of 1000 watt-cm of heat-transport capability.

  16. SAFE Alkali Metal Heat Pipe Reliability

    NASA Astrophysics Data System (ADS)

    Reid, Robert S.

    2003-01-01

    Alkali metal heat pipes are among the best understood and tested of components for first generation space fission reactors. A flight reactor will require production of a hundred or more heat pipes with assured reliability over a number of years. To date, alkali metal heat pipes have been built mostly in low budget development environments with little formal quality assurance. Despite this, heat pipe test samples suggest that high reliability can be achieved with the care justified for space flight qualification. Fabrication procedures have been established that, if consistently applied, ensure long-term trouble-free heat pipe operation. Alkali metal heat pipes have been successfully flight tested in micro gravity and also have been shown capable of multi-year operation with no evidence of sensitivity to fast neutron fluence up to 1023 n/cm2. This represents 50 times the fluence of the proposed Safe Affordable Fission Engine (SAFE-100) heat pipe reactor core.

  17. Underground pipe inspection device and method

    DOEpatents

    Germata, Daniel Thomas (Wadsworth, IL)

    2009-02-24

    A method and apparatus for inspecting the walls of an underground pipe from inside the pipe in which an inspection apparatus having a circular planar platform having a plurality of lever arms having one end pivotably attached to one side of the platform, having a pipe inspection device connected to an opposite end, and having a system for pivoting the lever arms is inserted into the underground pipe, with the inspection apparatus oriented with the planar platform disposed perpendicular to the pipe axis. The plurality of lever arms are pivoted toward the inside wall of the pipe, contacting the inside wall with each inspection device as the apparatus is conveyed along a length of the underground pipe.

  18. Emission characteristics of organic light-emitting diodes and organic thin-films with planar and corrugated structures.

    PubMed

    Wei, Mao-Kuo; Lin, Chii-Wann; Yang, Chih-Chung; Kiang, Yean-Woei; Lee, Jiun-Haw; Lin, Hoang-Yan

    2010-01-01

    In this paper, we review the emission characteristics from organic light-emitting diodes (OLEDs) and organic molecular thin films with planar and corrugated structures. In a planar thin film structure, light emission from OLEDs was strongly influenced by the interference effect. With suitable design of microcavity structure and layer thicknesses adjustment, optical characteristics can be engineered to achieve high optical intensity, suitable emission wavelength, and broad viewing angles. To increase the extraction efficiency from OLEDs and organic thin-films, corrugated structure with micro- and nano-scale were applied. Microstructures can effectively redirects the waveguiding light in the substrate outside the device. For nanostructures, it is also possible to couple out the organic and plasmonic modes, not only the substrate mode. PMID:20480033

  19. Corrugations and eccentric spirals in Saturn's D ring: New insights into what happened at Saturn in 1983

    E-print Network

    Hedman, M M; Showalter, M R

    2014-01-01

    Previous investigations of Saturn's outer D ring (73,200-74,000 km from Saturn's center) identified periodic brightness variations whose radial wavenumber increased linearly over time. This pattern was attributed to a vertical corrugation, and its temporal variability implied that some event --possibly an impact with interplanetary debris-- caused the ring to become tilted out the planet's equatorial plane in 1983. This work examines these patterns in greater detail using a more extensive set of Cassini images in order to obtain additional insights into the 1983 event. These additional data reveal that the D ring is not only corrugated, but also contains a time-variable periodic modulation in its optical depth that probably represents organized eccentric motions of the D-ring's particles. This second pattern suggests that whatever event tilted the rings also disturbed the radial or azimuthal velocities of the ring particles. Furthermore, the relative amplitudes of the two patterns indicate that the vertical m...

  20. Experimental Demonstration of Longitudinal Beam Phase-Space Linearizer in a Free-Electron Laser Facility by Corrugated Structures

    NASA Astrophysics Data System (ADS)

    Deng, Haixiao; Zhang, Meng; Feng, Chao; Zhang, Tong; Wang, Xingtao; Lan, Taihe; Feng, Lie; Zhang, Wenyan; Liu, Xiaoqing; Yao, Haifeng; Shen, Lei; Li, Bin; Zhang, Junqiang; Li, Xuan; Fang, Wencheng; Wang, Dan; Couprie, Marie-emmanuelle; Lin, Guoqiang; Liu, Bo; Gu, Qiang; Wang, Dong; Zhao, Zhentang

    2014-12-01

    Removal of the undesired time-energy correlations in the electron beam is of paramount importance for efficient lasing of a high-gain free-electron laser. Recently, it has been theoretically and experimentally demonstrated that the longitudinal wakefield excited by the electrons themselves in a corrugated structure allows for precise control of the electron beam phase space. In this Letter, we report the first utilization of a corrugated structure as a beam linearizer in the operation of a seeded free-electron laser driven by a 140 MeV linear accelerator, where a gain of ˜10 000 over spontaneous emission was achieved at the second harmonic of the 1047 nm seed laser, and a free-electron laser bandwidth narrowing by 50% was observed, in good agreement with the theoretical expectations.

  1. Emission Characteristics of Organic Light-Emitting Diodes and Organic Thin-Films with Planar and Corrugated Structures

    PubMed Central

    Wei, Mao-Kuo; Lin, Chii-Wann; Yang, Chih-Chung; Kiang, Yean-Woei; Lee, Jiun-Haw; Lin, Hoang-Yan

    2010-01-01

    In this paper, we review the emission characteristics from organic light-emitting diodes (OLEDs) and organic molecular thin films with planar and corrugated structures. In a planar thin film structure, light emission from OLEDs was strongly influenced by the interference effect. With suitable design of microcavity structure and layer thicknesses adjustment, optical characteristics can be engineered to achieve high optical intensity, suitable emission wavelength, and broad viewing angles. To increase the extraction efficiency from OLEDs and organic thin-films, corrugated structure with micro- and nano-scale were applied. Microstructures can effectively redirects the waveguiding light in the substrate outside the device. For nanostructures, it is also possible to couple out the organic and plasmonic modes, not only the substrate mode. PMID:20480033

  2. Evaluation of the transverse shear stiffness of a steel bi-directional corrugated-strip-core sandwich beam

    Microsoft Academic Search

    M. Leekitwattana; S. W. Boyd; R. A. Shenoi

    2011-01-01

    This paper presents a new concept in steel bi-directional corrugated-core sandwich structures. The focus is on the derivation of the transverse shear stiffness DQy of a sandwich beam using analytical methods. A braced frame analogy and its periodical unit cell, based on a force–distortion relationship concept, are used as the basis for deriving transverse shear stiffness relationships using the modified

  3. Two-phase friction pressure drop through corrugated tubes and quick-disconnect attachments in reduced gravity

    E-print Network

    Marsden, Kenneth

    1996-01-01

    . Single-phase pressure drop measurements were taken on the ground and two-phase reduced gravity tneasurements were obtained on the NASA KC-135. The purpose of this work was to evaluate pressure drop information from the corrugated tubes and quick.... ACKNOWLEDGMENTS A number of individuals and organizations have contributed significantly to the achievement of this thesis. I would like to thank Kathryn Miller and John Dezenitis and the Crew and Thermal Systems and Power and Propulsion divisions at NASA...

  4. Stress-based model on work hardening and softening of materials at large strains: corrugation process of sheet

    Microsoft Academic Search

    E. Hosseini; M. Kazeminezhad

    2009-01-01

    In this article, a stress-based model is proposed to investigate the strength evolution during severe plastic deformation\\u000a (SPD) or large strains. In this model, the work hardening mechanisms are described by Frank-Read sources, while the cross-slip\\u000a and climb processes are considered as the mechanisms for work softening phenomenon. Within all SPD processes, one of corrugation\\u000a processes such as constrained groove

  5. Particle trap to sheath non-binding contact for a gas-insulated transmission line having a corrugated outer conductor

    DOEpatents

    Fischer, William H. (Pittsburgh, PA)

    1984-04-24

    A non-binding particle trap to outer sheath contact for use in gas insulated transmission lines having a corrugated outer conductor. The non-binding feature of the contact according to the teachings of the invention is accomplished by having a lever arm rotatably attached to a particle trap by a pivot support axis disposed parallel to the direction of travel of the inner conductor/insulator/particle trap assembly.

  6. Tunable and efficient terahertz radiation generation by photomixing of two super Gaussian laser pulses in a corrugated magnetized plasma

    NASA Astrophysics Data System (ADS)

    Varshney, Prateek; Sajal, Vivek; Singh, Kunwar Pal; Kumar, Ravindra; Sharma, Navneet K.

    2015-05-01

    A scheme of terahertz (THz) radiation generation is investigated by photo-mixing of two super Gaussian laser beams having different frequencies ( ? 1 , ? 2 ) and wave numbers ( k ? 1 , k ? 2 ) in a performed corrugated plasma embedded with transverse dc magnetic field. Lasers exert a nonlinear ponderomotive force, imparting an oscillatory velocity to plasma electrons that couples with the density corrugations ( n ' = n ? 0 e i ? z ) to generate a strong transient nonlinear current, that resonantly derives THz radiation of frequency ˜ ? h (upper hybrid frequency). The periodicity of density corrugations is suitably chosen to transfer maximum momentum from lasers to THz radiation at phase matching conditions ? = ? 1 - ? 2 and k ? = k ? 1 - k ? 2 + ? ? . The efficiency, power, beam quality, and tunability of the present scheme exhibit high dependency upon the applied transverse dc magnetic field along with q-indices and beam width parameters ( a 0 ) of super Gaussian lasers. In the present scheme, efficiency ˜10-2 is achieved with the optimization of all these parameters.

  7. Dual manifold heat pipe evaporator

    DOEpatents

    Adkins, D.R.; Rawlinson, K.S.

    1994-01-04

    An improved evaporator section is described for a dual manifold heat pipe. Both the upper and lower manifolds can have surfaces exposed to the heat source which evaporate the working fluid. The tubes in the tube bank between the manifolds have openings in their lower extensions into the lower manifold to provide for the transport of evaporated working fluid from the lower manifold into the tubes and from there on into the upper manifold and on to the condenser portion of the heat pipe. A wick structure lining the inner walls of the evaporator tubes extends into both the upper and lower manifolds. At least some of the tubes also have overflow tubes contained within them to carry condensed working fluid from the upper manifold to pass to the lower without spilling down the inside walls of the tubes. 1 figure.

  8. Dual manifold heat pipe evaporator

    DOEpatents

    Adkins, Douglas R. (Albuquerque, NM); Rawlinson, K. Scott (Albuquerque, NM)

    1994-01-01

    An improved evaporator section for a dual manifold heat pipe. Both the upper and lower manifolds can have surfaces exposed to the heat source which evaporate the working fluid. The tubes in the tube bank between the manifolds have openings in their lower extensions into the lower manifold to provide for the transport of evaporated working fluid from the lower manifold into the tubes and from there on into the upper manifold and on to the condenser portion of the heat pipe. A wick structure lining the inner walls of the evaporator tubes extends into both the upper and lower manifolds. At least some of the tubes also have overflow tubes contained within them to carry condensed working fluid from the upper manifold to pass to the lower without spilling down the inside walls of the tubes.

  9. Heat-Pipe Wick Characterization

    SciTech Connect

    JONES II,JERRY LEE

    2000-08-15

    The development of liquid metal heat-pipes for use in solar powered Stirling engines has led to an in-depth analysis of heat-pipe wick properties. To model the flow of liquid sodium through the wick its two-phase permeability measurement is of interest. The permeability will be measured by constructing a test cell made up of a wick sample sintered to a manifold. Measuring the volumetric flow rate through the wick will allow for a determination of the wick's permeability as a function of pressure. Currently, simple estimates of permeability as a function of vapor fraction of a porous media are being used as a model to calculate the two-phase permeability. The above mentioned experiment will be used to test the existing formulas validity. The plan is to make use of a known procedure for testing permeability and apply those techniques to a felt-metal wick. The results will be used to verify and/or modify the two-phase permeability estimates. With the increasing desire to replace directly illuminated engines with the much more efficient heat-pipe apparatus it is inherently clear that the usefulness of known wick properties will make wick permeability design a simpler process.

  10. INTERIOR VIEW WITH LARGE PIPE CASTING MACHINE CASTING A 48' ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW WITH LARGE PIPE CASTING MACHINE CASTING A 48' PIPE OPERATOR SPRAYING A POWDER TO HELP SOLIDIFY THE PIPE BEING CENTRIFUGALLY CAST. - United States Pipe & Foundry Company Plant, Pipe Casting & Testing Area, 2023 St. Louis Avenue at I-20/59, Bessemer, Jefferson County, AL

  11. Update: pipes of different half bend angles Feb. 21, 2013

    E-print Network

    McDonald, Kirk

    Update: pipes of different half bend angles Feb. 21, 2013 Yan Zhan 1 #12;Outline · Mercury Supply Pipe · Re-mesh for Pipes without weld of different half bend angles · Turbulence Intensity At Pipe Exits · Discussion on Bend Effects and Nozzle Effects 2 #12;Mercury Supply Pipe 3 Item 2 Item 3 Whole

  12. Piping and pipeflow in a deep peat catchment

    Microsoft Academic Search

    J. Holden; T. P. Burt

    2002-01-01

    Natural pipes are common in many upland blanket peats, yet little is known about pipe network morphology or pipeflow processes. Most information on soil piping comes from the shallow peaty podzols of the Welsh uplands, where monitoring suggests that pipes may be important contributors to streamflow. This paper presents information on piping and pipeflow from a deep upland blanket peat

  13. Heat-Pipe-Cooled Leading Edges for Hypersonic Vehicles

    NASA Technical Reports Server (NTRS)

    Glass, David E.

    2006-01-01

    Heat pipes can be used to effectively cool wing leading edges of hypersonic vehicles. . Heat-pipe leading edge development. Design validation heat pipe testing confirmed design. Three heat pipes embedded and tested in C/C. Single J-tube heat pipe fabricated and testing initiated. HPCLE work is currently underway at several locations.

  14. Improving wet and dry strength properties of recycled old corrugated carton (OCC) pulp using various polymers.

    PubMed

    Hamzeh, Yahya; Sabbaghi, Sanaz; Ashori, Alireza; Abdulkhani, Ali; Soltani, Farshid

    2013-04-15

    In this study, the application of different dosages of low and high molecular weights (MW) of chitosan (Ch), cationic starch (CS) and poly vinyl alcohol (PVA) were systematically investigated using old corrugated carton (OCC) furnishes. Various sequences of above-mentioned polymeric additives were also examined to find out the optimal combination for improving both wet and dry tensile strength. For each treatment, 4 handsheets, each having basis weight of 100 g/m(2), were made. In general, the tensile strength of handsheets was significantly affected by the addition of polymeric agents. The enhancing effect of additives on dry tensile property was much higher than wet condition. The results also showed that the tensile strength of the samples made from OCC furnishes were improved upon the addition of high molecular weight chitosan (ChI) compared to the untreated ones (control). The low MW chitosan did not change the properties of handsheets dramatically. Application of polymeric agents moderately decreased the stretch to rupture, however with increasing dosage the stretch was improved. Sequential addition of used polymers showed that triple application of polymers was beneficial to both dry and wet tensile strength, although the effect was larger for dry. The best results in wet and dry tensile strengths were achieved using sequential of PVA-ChI-CS. Sequential addition of oppositely charged polymers forms a macromolecular layered structure of polyelectrolytes. PMID:23544577

  15. Magnetoreflectance of films with corrugated surfaces, with magnetic fields applied in the perpendicular configuration

    NASA Astrophysics Data System (ADS)

    Jacobo-Escobar, J. H.; Martínez, G.; Cocoletzi, Gregorio H.

    1999-03-01

    The effects of external magnetic 0953-8984/11/8/009/img1-fields on the scattering of p-polarized light from metallic films with corrugated surfaces are investigated, with 0953-8984/11/8/009/img1 along the growth axis (in the perpendicular configuration). The Rayleigh-Fano and transfer-matrix approaches are applied to obtain 0953-8984/11/8/009/img3 for the scattered fields, with the specular magnetoreflection 0953-8984/11/8/009/img4 displaying minima due to the coupling of the incident light with the surface magnetoplasmons at frequencies in the range 0953-8984/11/8/009/img5, where 0953-8984/11/8/009/img6 and 0953-8984/11/8/009/img7 are the cyclotron and hybrid frequencies, respectively, with the gap of the splitting decreasing as the magnetic field strength increases. The presence of a metallic superlattice inhibits the gap between the minima of the surface magnetoplasmon polaritons. In addition, a pseudosurface magnetoplasmon polariton is manifested for both geometries for 0953-8984/11/8/009/img8.

  16. Lateral interactions and corrugation in physisorption systems: CH4/Cu(100)

    NASA Astrophysics Data System (ADS)

    Wei, D.-H.; Skelton, D. C.; Kevan, S. D.

    1996-11-01

    We present and analyze isothermal adsorption and desorption measurements for methane physisorbed on a Cu(100) surface to characterize the interplay between molecule-surface and molecule-molecule interactions. A 2D gas-liquid phase boundary for the methane layer is observed and partially mapped in coverage and temperature. Comparing our measured critical temperature of 66 K ±2 K to previous work on related systems implies an attractive well between physisorbed molecules of ˜130 K. This reduction compared to the gas phase well can be adequately understood in terms of dielectric screening of the dispersion interaction. By contrast, analyzing the low-coverage adsorption and desorption isotherms using a quasiequilibrium model and imperfect gas statistics, we deduce a lateral attractive intermolecular potential well of only 40-50 K. This drastic reduction of the attractive well from the gas phase value is not consistent with image charge screening, and is difficult to reconcile with the observed critical temperature. This discrepancy is discussed in terms of surface corrugation which dictates different positions for molecule-surface and molecule-molecule potential energy minima.

  17. Tribological characteristics of corrugated nano-scale dimpled and nanostructured surfaces.

    PubMed

    Park, In-Gyu; Lee, Chang-Soon; Cho, In-Shik

    2013-12-01

    The effects of ultrasonic nanocrystalline surface modification (UNSM) on the tribological characteristics of two different Cu-based alloys sintered on low carbon steel were investigated using a ball-on-disk reciprocating tribometer with a hardened bearing steel ball under oil-lubricated conditions. Experimental results showed that both the UNSM-treated Cu-based alloy specimens reduced the friction coefficient and enhanced the wear resistance compared to those of the polished specimens. Improvements in tribological characteristics of the UNSM-treated specimens may be attributed to the corrugated nano-scale dimpled and nanostructured surfaces and increased hardness. Addition of the 0.52% ferrum to Cu-based alloy is found to be beneficial in improving the tribological characteristics and in reducing the grain size. Scanning electron microscopy (SEM) was utilized to analyze the worn surfaces and characterize the wear mechanisms of the polished and UNSM-treated specimens. SEM analyses showed that the UNSM could reduce the abrasive wear which was the dominant wear mechanism of both Cu-based alloys specimens. In addition, the density and porosity measurement of both sintered Cu-based alloys revealed that the density increased and the porosity decreased after UNSM. PMID:24266221

  18. Performance enhancement of piezoelectric energy harvesting system using a corrugated cantilever beam

    NASA Astrophysics Data System (ADS)

    Park, Jeongsu; Kim, In-ho; Jin, SeungSeop; Koo, Jeong-Hoi; Jung, Hyung-Jo

    2014-03-01

    In this paper, a piezoelectric energy harvesting device consisting of a proof mass and a corrugated cantilever beam is proposed in order to enhance its performance (i.e., an increase in output voltage as well as a reduction in resonant frequency). The sinusoidal or trapezoidal shape of a cantilever beam is able to make the bonding area of piezoelectric materials (e.g., polyvinylidene fluoride (PVDF) film) much larger, resulting in higher output voltages. Moreover, the natural frequency of the device can be significantly decreased due to low flexural rigidity of the beam member. This lownatural frequency device would fit well for civil engineering applications because most civil structures such as bridges and buildings have low natural frequencies. In order to examine the geometrical characteristics of the proposed device, an analytical development and a numerical simulation are carried out. Besides, shaking table tests are conducted with a prototype of energy harvesting device. It is demonstrated from numerical and experimental studies that the proposed energy harvester can shift down its resonant frequency considerably and generate much higher output power as compared with a conventional one having a flat (or straight) cantilever beam.

  19. Anomalous features of diffusion in corrugated potentials with spatial correlations: faster than normal, and other surprises.

    PubMed

    Goychuk, Igor; Kharchenko, Vasyl O

    2014-09-01

    Normal diffusion in corrugated potentials with spatially uncorrelated Gaussian energy disorder famously explains the origin of non-Arrhenius exp[-?2/(kBT2)] temperature dependence in disordered systems. Here we show that unbiased diffusion remains asymptotically normal also in the presence of spatial correlations decaying to zero. However, because of a temporal lack of self-averaging, transient subdiffusion emerges on the mesoscale, and it can readily reach macroscale even for moderately strong disorder fluctuations of ??4-5kT. Because of its nonergodic origin, such subdiffusion exhibits a large scatter in single-trajectory averages. However, at odds with intuition, it occurs essentially faster than one expects from the normal diffusion in the absence of correlations. We apply these results to diffusion of regulatory proteins on DNA molecules and predict that such diffusion should be anomalous, but much faster than earlier expected on a typical length of genes for a realistic energy disorder of several room kBT, or merely 0.05-0.075??eV. PMID:25238342

  20. Spontaneous acoustic emission of a corrugated shock wave in the presence of a reflecting surface.

    PubMed

    Wouchuk, J G; López Cavada, J

    2004-10-01

    An analytic model to study perturbation evolution in the space between a corrugated shock and a piston surface is presented. The conditions for stable oscillation patterns are obtained by looking at the poles of the exact Laplace transform. It is seen that besides the standard D'yakov-Kontorovich (DK) mode of oscillation, the shock surface can exhibit an additional finite set of discrete frequencies, due to the interaction with the piston which reflects sound waves from behind. The additional eigenmodes are excited when the shock is launched at t= 0(+) . The first eigenmode (the DK mode) is always present, if the Hugoniot curve has the correct slope in the V-p plane. However, the additional frequencies could be excited for strong enough shocks. The predictions of the model are verified for particular cases by studying a van der Waals gas, as in the work of Phys. Fluids 11, 462 (1999)]; Phys. Rev. Lett. 84, 1180 (2000)]. Only acoustic emission modes are considered. PMID:15600515

  1. Single-step holographic fabrication of large-area periodically corrugated metal films

    PubMed Central

    Lu, Mengqian; Krishna Juluri, Bala; Zhao, Yanhui; Jun Liu, Yan; Bunning, Timothy J.; Jun Huang, Tony

    2012-01-01

    We have developed a simple, high-throughput, and cost-effective method to fabricate one-dimensional and two-dimensional periodically corrugated silver films over centimeter scale areas. This fabrication uses a single-step holographic patterning technique with laser intensities as low as 88.8 mW/cm2 to deposit silver nanoparticles directly from solution to create gratings with periodicities of 570?nm. A dip in the transmission spectrum for these samples is observed due to certain visible wavelengths coupling to surface plasmon polaritons (SPPs) and the peak wavelength of this dip has a linear relationship with the surrounding material's refractive index (RI) with a sensitivity of 553.4?nm/RIU. The figure of merit (the ratio of refractive index sensitivity to the full width at half maximum (FWHM)) is typically in the range of 12–23. Our technique enables single-step fabrication of uniform, sub-wavelength periodic metal structures over a large area with low cost. Such sub-wavelength periodic metal structures are promising candidates as disposable sensors in applications such as affordable environmental monitoring systems and point-of-care diagnostics. PMID:23284185

  2. Evaluation of a tri-wall corrugated fibreboard package for packaging and transporting LSA nonretrievable waste

    SciTech Connect

    Saiki, D.M.; Aguilar, P.G.

    1981-01-01

    An evaluation was conducted to determine if an economical Tri-Wall Corrugated Fiberboard (TWCF) Package could be used for transporting LSA nonretrievable wastes (< 10 nCi/g radioactive contamination). A complete description of the packaging configuration was given. The evaluation included Vibration Tests to determine if the TWCF Package would comply with the present DOT regulation for packaging LSA waste (i.e. the package must be a strong-tight package that will not leak material under conditions normally incident to transport). Presently, no specific tests are required to determine compliance. Additional tests were conducted to determine performance of the package under selected adverse and hypothetical accidental conditions. No significant damage or loss of waste material occurred during the Vibration Tests thus indicating compliance with the present DOT regulation. The other performance tests indicated that some loss of waste material would occur under certain accidental conditions, however, the loss would be minimal. As a result of these performance tests, certain operating limitations and precautions regarding the handling and use of the package were given. Since the TWCF Package appears to meet DOT regulations and performed favorably under certain selected adverse and hypothetical accidential conditions, it was recommended for use in transporting certain types and forms of LSA nonretrievable wastes.

  3. Material selection for elastic energy absorption in origami-inspired compliant corrugations

    NASA Astrophysics Data System (ADS)

    Tolman, Sean S.; Delimont, Isaac L.; Howell, Larry L.; Fullwood, David T.

    2014-09-01

    Elastic absorption of kinetic energy and distribution of impact forces are required in many applications. Recent attention to the potential for using origami in engineering may provide new methods for energy absorption and force distribution. A three-stage strategy is presented for selecting materials for such origami-inspired designs that can deform to achieve a desired motion without yielding, absorb elastic strain energy, and be lightweight or cost effective. Two material indices are derived to meet these requirements based on compliant mechanism theory. Finite element analysis is used to investigate the effects of the material stiffness in the Miura-ori tessellation on its energy absorption and force distribution characteristics compared with a triangular wave corrugation. An example is presented of how the method can be used to select a material for a general energy absorption application of the Miura-ori. Whereas the focus of this study is the Miura-ori tessellation, the methods developed can be applied to other tessellated patterns used in energy absorbing or force distribution applications.

  4. Electromagnetic properties of corrugated and smooth waveguides filled with radially inhomogeneous plasma

    SciTech Connect

    Shkvarunets, A.G.; Kobayashi, S.; Weaver, J.; Carmel, Y.; Rodgers, J.; Antonsen, T.M. Jr.; Granatstein, V.L.; Destler, W.W. [Univ. of Maryland, College Park, MD (United States)] [Univ. of Maryland, College Park, MD (United States)

    1996-06-01

    Creation and diagnosis of plasma in microwave devices remains one of the primary challenges of plasma microwave electronics. In the present work the authors deal with (1) diagnostic techniques for characterization of radially nonuniform plasma columns suitable for use in high-power microwave sources and (2) the effects of such plasmas on the electromagnetic properties of finite length, spatially periodic slow wave structures. Experimental studies were performed both for a strong and a weak guiding magnetic field. Using a combination of a microwave resonator (X-band) and a Langmuir probe, both the plasma peak density and its transverse profile were measured in situ (prior to beam propagation). The frequency upshifts of the TM{sub 01n} modes in an open corrugated cavity were measured as a function of the background plasma density. The dispersion diagrams were reconstructed, for the first time, up to a peak plasma density of 10{sup 12} cm{sup {minus}3}. Frequency upshifts and flattening of the dispersion curves were observed for both strong and weak guiding magnetic fields. For plasma density above 5 {times} 10{sup 11} cm{sup {minus}3} the frequency upshifts are less than anticipated by theory.

  5. Pressure drop testing of corrugated stainless steel pliable gas tubing (PLT)

    NASA Astrophysics Data System (ADS)

    Srinivasan, Bharadwaj

    An experimental program was initiated to determine the Darcy friction factor in straight corrugated stainless steel pliable gas tubing (PLT). Pressure loss tests were conducted on PLT per I.S. EN 15266:2007. A power law least-squares curve fit was used to relate pressure loss per unit length as a function of volume flow rate. The calculated coefficient of determination values for the straight PLT exceeded 0.90 indicating suitable correlation. Darcy friction factors were calculated from test data for each case and plotted on a Moody diagram as a function of Reynolds number based on the minimum PLT cross section. For Reynolds numbers less than 2300 the pressure loss data for PLT yielded an inverse relationship between the Darcy friction factor and the Reynolds number, with a proportionality coefficient of 49. The measurement uncertainty estimates for straight sections was performed with a 95% confidence level. Straight PLT flow rates for air and representative fuel gases that would yield a pressure loss Deltap = 1 mbar were calculated as a function of PLT length and diameter. Fitting pressure loss tests were performed for elbows, tees, and bullhead tees. The loss coefficients were evaluated and tabulated. The calculated coefficient of determination values for the fittings was found to be low. The measurement uncertainty was calculated using the root sum square error method and was found to be very high because of the low flow rates considered in this experiment.

  6. Extended Development of Variable Conductance Heat Pipes

    NASA Technical Reports Server (NTRS)

    Antoniuk, D.; Edwards, D. K.; Luedke, E. E.

    1978-01-01

    A high-capacity vapor-modulated heat pipe was designed and tested. In 1977, a program was undertaken to use the aforementioned heat pipe to study protection from freezing-point failure, increase control sensitivity, and transient behavior under a wide range of operating conditions in order to determine the full performance potential of the heat pipe. A new concept, based on the vapor-induced-dry-out principle, was developed for passive feedback temperature control as a heat pipe diode. This report documents this work and describes: (1) the experimental and theoretical investigation of the performance of the vapor-modulated heat pipe; and (2) the design, fabrication and test of the heat pipe diode.

  7. Piping inspection carriage having axially displaceable sensor

    DOEpatents

    Zollinger, W.T.; Treanor, R.C.

    1994-12-06

    A pipe inspection instrument carriage is described for use with a pipe crawler for performing internal inspections of piping surfaces. The carriage has a front leg assembly, a rear leg assembly and a central support connecting the two assemblies and for mounting an instrument arm having inspection instruments. The instrument arm has a Y-arm mounted distally thereon for axially aligning the inspection instrumentation and a mounting block, a linear actuator and axial movement arm for extending the inspection instruments radially outward to operably position the inspection instruments on the piping interior. Also, the carriage has a rotation motor and gear assembly for rotating the central support and the front leg assembly with respect to the rear leg assembly so that the inspection instruments azimuthally scan the piping interior. The instrument carriage allows performance of all piping inspection operations with a minimum of moving parts, thus decreasing the likelihood of performance failure. 4 figures.

  8. Piping inspection carriage having axially displaceable sensor

    DOEpatents

    Zollinger, William T. (Martinez, GA); Treanor, Richard C. (Augusta, GA)

    1994-01-01

    A pipe inspection instrument carriage for use with a pipe crawler for performing internal inspections of piping surfaces. The carriage has a front leg assembly, a rear leg assembly and a central support connecting the two assemblies and for mounting an instrument arm having inspection instruments. The instrument arm has a y-arm mounted distally thereon for axially aligning the inspection instrumentation and a mounting block, a linear actuator and axial movement arm for extending the inspection instruments radially outward to operably position the inspection instruments on the piping interior. Also, the carriage has a rotation motor and gear assembly for rotating the central support and the front leg assembly with respect to the rear leg assembly so that the inspection instruments azimuthally scan the piping interior. The instrument carriage allows performance of all piping inspection operations with a minimum of moving parts, thus decreasing the likelihood of performance failure.

  9. The dynamics of submarine geothermal heat pipes

    Microsoft Academic Search

    Wuming Bai; Wenyue Xu; Robert P. Lowell

    2003-01-01

    To better understand natural two-phase hydrothermal systems, we have constructed one-dimensional heat-pipe solutions for NaCl-H2O fluids and explored the effects of basal heat flux and permeability on their behavior. For seafloor conditions, saline brines form quickly at the base of the heat pipe; and in some cases halite is precipitated. NaCl-H2O heat pipes may become liquid or vapor dominated but,

  10. Microgravity performance of micro pulsating heat pipes

    Microsoft Academic Search

    Junjie Gu; Masahiro Kawaji; Ryosuke Futamata

    2005-01-01

    A micro pulsating heat pipe made of a thin clear Teflon tube of 1.6 mm ID was used to observe the pulsating flow inside a\\u000a heat pipe under different gravity levels using parabolic flights. More vigorous pulsating flow was observed under microgravity,\\u000a compared to the depressed movements under hypergravity. Two metallic micro pulsating heat pipes made of an aluminum plate

  11. Downhole pipe selection for acoustic telemetry

    DOEpatents

    Drumheller, D.S.

    1995-12-19

    A system is described for transmitting signals along a downhole string including a plurality of serially connected tubular pipes such as drill or production pipes, a transmitter for transmitting a signal along the string and a receiver for receiving the signal placed along the string at a location spaced from said transmitting means, wherein the pipes between the transmitter and the receiver are ordered according to length of tube to minimize loss of signal from said transmitter to said receiver. 7 figs.

  12. Downhole pipe selection for acoustic telemetry

    DOEpatents

    Drumheller, Douglas S. (Cedar Crest, NM)

    1995-01-01

    A system for transmitting signals along a downhole string including a plurality of serially connected tubular pipes such as drill or production pipes, a transmitter for transmitting a signal along the string and a receiver for receiving the signal placed along the string at a location spaced from said transmitting means, wherein the pipes between the transmitter and the receiver are ordered according to length of tube to minimize loss of signal from said transmitter to said receiver.

  13. Failure analysis of natural gas pipes

    Microsoft Academic Search

    Z. A. Majid; R. Mohsin; Z. Yaacob; Z. Hassan

    2010-01-01

    Incident involving failures of 6months old API 5L X42 (NPS8) and SDR 17, 125mm medium density polyethylene pipe (MDPE) supplying natural gas to an industrial customer has caused serious 7h supply disruption. Study was performed to identify the most probable cause of the pipes failures. The study conducted by reviewing the existing design and construction data, visual physical inspection, pipe

  14. Pipe-in-pipe insulation system passes tests for reel lay

    Microsoft Academic Search

    Mollison

    1992-01-01

    The first reeled installation of the thermally insulated pipeline system known as pipe-in-pipe (PIP) occurred in development of the Seahorse and Tarwhine fields in Bass Strait, Australia, in 1989. This paper reports that PIP consists of an inner steel pipe coated with high-density polyurethane (HDPU) foam inside an outer steel carrier pipe. The lines are 7 and 10.8 miles, respectively,

  15. Modeling of transient heat pipe operation

    NASA Technical Reports Server (NTRS)

    Colwell, G. T.; Hartley, J. G.

    1985-01-01

    The overall goal is to gain a better understanding of the transient behavior of heat pipes operating under both normal and adverse conditions. Normal operation refers to cases where the capillary structure remains fully wetted. Adverse operation occurs when drying, re-wetting, choking, noncontinuum flow, freezing, thawing etc., occur within the heat pipe. The work was redirected towards developing the capability to predict operational behavior of liquid metal heat pipes used for cooling aerodynamic structures. Of particular interest is the startup of such heat pipes from an initially frozen state such as might occur during re-entry of a space vehicle into the Earth's atmosphere or during flight of hypersonic aircraft.

  16. Heat Pipe Technology for Refrigeration and Cooling

    Microsoft Academic Search

    H. F. Smirnov

    \\u000a A main goal of this review was an exchange of the essential ideas and practical problems of heat pipe technology use for refrigeration\\u000a and cooling, with respect to the following most perspective spotlights:\\u000a \\u000a \\u000a \\u000a 1. \\u000a \\u000a Heat pipes and especially loop heat pipes application as a safe external or internal thermal link.\\u000a \\u000a \\u000a \\u000a 2. \\u000a \\u000a Heat pipe technology as a base for refrigerating heat

  17. Water pipe smoking and dermatologic consequences.

    PubMed

    Wollina, U

    2015-08-01

    Water pipe smoking is a recently growing addiction worldwide. It has become popular in Africa and the Western World and enfaces a renaissance in Middle East and Asia. The smoking technique leads to a different exposure to potential hazardous compounds compared to cigarette or classical pipe smoking. The common assumption that water pipe smoking is less dangerous to health is not substantiated by scientific data. Non-tobacco-based preparations reduce the exposure to nicotine but may contain equal or even higher concentrations of other toxic compounds. The medical literature on adverse effect of water pipe smoking on skin and oral mucosa is reviewed but future research is a demand. PMID:25677592

  18. Heat pipe transient measurements incorporating visual methods 

    E-print Network

    DeHart, Mark David

    1986-01-01

    pipes have been given heavy consider ation in many different phases of proposed space based power systems. The General Electric design for the SP-100 space power system will utilize heat pipes for a radiative heat r ejection system. The application... the application of heat pipes to nuclear tr. er mionics. The value of heat p!oes had been r ecognized, , and heat pipe experimentation and r esear ch picked up. The potential fon space applications was r ecognized, anc soon J. Devenall and J. E. Kemme...

  19. A pipe-profiling adapter for CCTV inspection cameras: development of a pipe-profiling instrument

    Microsoft Academic Search

    R. Henry; A. R. Luxmoore

    1996-01-01

    The principle of the optical section has been used to develop a profiling attachment for CCTV pipe inspection cameras. A light source, placed in front of the camera, projects a ring of light onto the pipe wall, which is then viewed by the camera. Any distortion in the pipe wall will be made visible by the light ring. The CCTV

  20. The Politics of the Pipe: Clay Pipes and Tobacco Consumption in Galway, Ireland

    Microsoft Academic Search

    Alexandra Hartnett

    2004-01-01

    In this paper, clay pipes and the historical record are used to explore the illicit importation of tobacco in seventeenth-century Galway, Ireland. This is part of a wider tradition of the politics of smoking, including the proliferation of the clay pipe, the widespread smuggling of tobacco, and the overtly political nineteenth-century pipes that touted nationalist emblems. Here, the juxtaposition of