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1

Safe end treatments for roadside drainage culverts  

E-print Network

by natural drainage channels. The two basic types of cross- drainage culverts are pipe culverts and box culverts. Two major areas concerning cross-drainage culverts are accommoda- ting surface runoff along the highway right-of-way and incorporating safety...-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...

Jackson, Benito

1980-01-01

2

78 FR 5715 - Construction and Maintenance-Culvert Pipe Selection  

Federal Register 2010, 2011, 2012, 2013, 2014

...Autonomy for Culvert Pipe Selection,'' requires the Secretary...culvert and storm sewer type selection to either: (a) Include...would have to fit into the natural and constructed environment...to State DOTs regarding the selection of culvert and storm...

2013-01-28

3

Culvert pipe materials and durability: Making the right  

E-print Network

Culvert pipe materials and durability: Making the right selection for Minnesota Presented by: Craig. The actual service life of infrastructure is less than expected 2. Advances in pipe materials & federal Manual (Chapter 2) #12;What causes pipes to deteriorate? · Acidity/alkalinity of water and soil (p

Minnesota, University of

4

Corrugated Pipe as a Beam Dechirper  

SciTech Connect

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.

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

2012-04-20

5

Study of the use of truck tire beads as drainage pipe and analysis of the economics of tire disposal in Oklahoma. Part 1. Culverts. Final report  

SciTech Connect

In an attempt to find alternate ways of dealing with waste truck tires, a private tire recycling company developed a pipe from the tire bead and sidewall. The tire-pipe has seen limited use as a roadway drainage culvert. To encourage wider use of this product, an evaluation of pipe performance was performed. The evaluation consisted of (1) inspections of existing installations; (2) structural tests; and (3) leakage tests. The study found that the majority of installations were performing well. Compared with corrugated steel and fiberglass pipes, the tire-pipe exhibited favorable structural performance. An individual tire-pipe section was found to be watertight. However, when tested in the open-air (not in the ground), the tire-pipe joints were found to leak. Development of an improved end connection would improve the utility of the tire-pipe.

Everett, J.W.; Gattis, J.L.

1994-07-01

6

Whistling of a pipe system with multiple side branches: Comparison with corrugated pipes  

Microsoft Academic Search

Corrugated pipes are widely used because they combine local rigidity with global flexibility. Whistling induced by flow through such pipes can lead to serious environmental and structural problems. The whistling of a multiple side branch system is compared to the whistling behavior of corrugated pipes. The study has been restricted to cavities with sharp edges which are convenient for theoretical

D. Tonon; B. J. T. Landry; S. P. C. Belfroid; J. F. H. Willems; G. C. J. Hofmans; A. Hirschberg

2010-01-01

7

Stability of steady flow through an axially corrugated pipe  

NASA Astrophysics Data System (ADS)

The linear stability of steady flow in pipes with circular cross-section and sinusoidal axial variation in diameter is studied by finding global eigenmodes with axial wavelength commensurate with that of the wall corrugation, chosen to be equal to one pipe mean radius. The maximum peak-to-peak height of corrugation considered is approximately 8% of the mean diameter. At low corrugation amplitude and at low Reynolds numbers, the base flow remains attached to the wall, while at larger amplitudes and Reynolds numbers, an axisymmetric separation bubble forms within the corrugation. For all Reynolds numbers considered, flows remain stable to axisymmetric perturbations, but become unstable to standing-wave modes of low azimuthal wavenumber, with critical Reynolds number first falling, then increasing with increasing corrugation height. Both attached and separated flows exhibit similar types of instability modes, which in the case of separated flow are most energetic near the reattachment line of the base flow. The leading instability modes consist of counter-rotating vortices situated near the pipe wall.

Loh, S. A.; Blackburn, H. M.

2011-11-01

8

Wall shape optimization for a thermosyphon loop featuring corrugated pipes  

NASA Astrophysics Data System (ADS)

In the present paper we address the problem of optimal wall-shape design of a single phase laminar thermosyphon loop. The model takes the buoyancy forces into account via the Boussinesq approximation. We focus our study on showing the effects of wall shape on the flow and on the temperature inside the thermosyphon. To this extend we determine the dependency of the flow rate and the increase in temperature, on the geometrical characteristics of the loop. The geometry considered is a set of axially symmetric corrugated pipes described by a set of parameters; namely the pipe inner radius, the period of the corrugation, the amplitude of the corrugation, and the ratio of expansion and contraction regions of a period of the pipe. The governing equations are solved using the Finite Element Method, in combination with an adaptive mesh refinement technique in order to capture the effects of wall shape. We characterize the effects of the amplitude and of the ratio of expansion and contraction. In particular we show that for a given fixed amplitude it is possible to find an optimal ratio of expansion and contraction that minimizes the temperature inside the thermosyphon. The results show that by adequately choosing the design parameters, the performance of the thermosyphon loop can be improved.

Rosen Esquivel, Patricio I.; ten Thije Boonkkamp, Jan H. M.; Dam, Jacques A. M.; Mattheij, Robert M. M.

2012-06-01

9

Terahertz Radiation from a Pipe with Small Corrugations  

SciTech Connect

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.

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

2012-01-26

10

Study of the use of truck tire beads as drainage pipe and analysis of the economics of tire disposal in Oklahoma. Part 1. Culverts. Final report  

Microsoft Academic Search

In an attempt to find alternate ways of dealing with waste truck tires, a private tire recycling company developed a pipe from the tire bead and sidewall. The tire-pipe has seen limited use as a roadway drainage culvert. To encourage wider use of this product, an evaluation of pipe performance was performed. The evaluation consisted of (1) inspections of existing

J. W. Everett; J. L. Gattis

1994-01-01

11

Surface Impedance Formalism for a Metallic Beam Pipe with Small Corrugations  

SciTech Connect

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.

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

2012-08-30

12

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

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

13

Using pipe with corrugated walls for a sub-terahertz FEL  

E-print Network

It has been noted in the past, in the study of the wall-roughness impedance, that a metallic pipe with corrugated walls supports propagation of a high-frequency mode that is in resonance with a relativistic beam. This mode can be excited by a beam whose length is a fraction of the wavelength. In this paper, we study another option of excitation of the resonant mode in a metallic pipe with corrugated walls---via the mechanism of the free electron laser instability. This mechanism works if the bunch length is much longer than the wavelength of the radiation.

Stupakov, Gennady

2014-01-01

14

Simulation and analysis on ultrasonic testing for the cement grouting defects of the corrugated pipe  

SciTech Connect

The defects exist in the cement grouting process of prestressed corrugated pipe may directly impair the bridge safety. In this paper, sound fields propagation in concrete structures with corrugated pipes and the influence of various different defects are simulated and analyzed using finite element method. The simulation results demonstrate a much complex propagation characteristic due to multiple reflection, refraction and scattering, where the scattering signals caused by metal are very strong, while the signals scattered by an air bubble are weaker. The influence of defect both in time and frequency domain are found through deconvolution treatment. In the time domain, the deconvolution signals correspond to larger defect display a larger head wave amplitude and shorter arrive time than those of smaller defects; in the frequency domain, larger defect also shows a stronger amplitude, lower center frequency and lower cutoff frequency.

Qingbang, Han; Ling, Chen; Changping, Zhu [Changzhou Key Laboratory of Sensor Networks and Environmental Sensing, College of IOT, Hohai University Changzhou, Jiangsu, 213022 (China)

2014-02-18

15

Simulation and analysis on ultrasonic testing for the cement grouting defects of the corrugated pipe  

NASA Astrophysics Data System (ADS)

The defects exist in the cement grouting process of prestressed corrugated pipe may directly impair the bridge safety. In this paper, sound fields propagation in concrete structures with corrugated pipes and the influence of various different defects are simulated and analyzed using finite element method. The simulation results demonstrate a much complex propagation characteristic due to multiple reflection, refraction and scattering, where the scattering signals caused by metal are very strong, while the signals scattered by an air bubble are weaker. The influence of defect both in time and frequency domain are found through deconvolution treatment. In the time domain, the deconvolution signals correspond to larger defect display a larger head wave amplitude and shorter arrive time than those of smaller defects; in the frequency domain, larger defect also shows a stronger amplitude, lower center frequency and lower cutoff frequency.

Qingbang, Han; Ling, Chen; Changping, Zhu

2014-02-01

16

Using pipe with corrugated walls for a subterahertz free electron laser  

NASA Astrophysics Data System (ADS)

A metallic pipe with corrugated walls supports propagation of a high-frequency mode that is in resonance with a relativistic beam propagating along the axis of the pipe. This mode can be excited by a beam whose length is a fraction of the wavelength. In this paper, we study another option of excitation of the resonant mode—via the mechanism of the free electron laser instability. This mechanism works if the bunch length is much longer than the wavelength of the radiation and, hence, does not require bunch compression. It provides an alternative to excitation by short bunches that can be realized with relatively low energy and low peak-current electron beams.

Stupakov, Gennady

2015-03-01

17

Measurements on tones generated in a corrugated flow pipe with special attention to the influence of a low frequency  

E-print Network

interest as the so called "singing riser" problem has become apparent in the natural gas industry. The long flexible pipes used for conveying gas are corrugated on the inside and are known to exhibit strong sound the singing riser problem are published by Reinen [6], Belfroid et al. [1]. In the study by Reinen, a 20m long

Paris-Sud XI, Université de

18

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

19

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

20

North concrete portal of Culvert No. 1423, Purslane Run Culvert, ...  

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

North concrete portal of Culvert No. 1423, Purslane Run Culvert, which connects to C&O Canal Culvert No. 211, looking east. - Western Maryland Railway, Cumberland Extension, Pearre to North Branch, from WM milepost 125 to 160, Pearre, Washington County, MD

21

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

PubMed

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

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

22

Singing Corrugated Pipes.  

ERIC Educational Resources Information Center

This article describes different techniques used to measure air flow velocity. The two methods used were Crawford's Wastebasket and a video camera. The results were analyzed and compared to the air flow velocity predicted by Bernoulli's principle. (ZWH)

Cadwell, Louis H.

1994-01-01

23

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

USGS Publications Warehouse

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.

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

2009-01-01

24

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...

25

CANDE-1980: Box culverts and soil models  

NASA Astrophysics Data System (ADS)

The CANDE computer program, introduced in 1976 for the structural design and analysis of buried culverts, is extended and enhanced in this work effort to include options for automated finite element analysis of precast, reinforced concrete box culverts, and new nonlinear soil models. User input instructions for the new options, now operative in the CANDE-1980 program, are provided in the appendix of this report along with example input/output data.

Katona, M. G.; Vittes, P. D.; Lee, C. H.; Ho, H. T.

1981-05-01

26

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

27

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

28

Cleaning process for corrugated aluminum electrical transmission line enclosure  

DOEpatents

A process for preparing the interior of a corrugated pipe or sheath comprises the steps of placing a predetermined amount of a tumbling abrasive material into the sheath, and then rotating the sheath.

Bowman, Gary K. (Westborough, MA)

1984-07-24

29

Earth pressures on reinforced concrete box culverts  

E-print Network

. - NOTATION APPENDIX III. - PRESSURE CELL DATA APPENDIX IV. - INFLUENCE DIAGRAMS APPENDIX V. - CALIBRATION DATA VITA 130 130 137 137 137 139 141 155 158 199 230 242 LIST OF TABLES Table 1. Soil Classification and Atterberg Limits Table 2..., Atterberg Limits, and effective stress shear strength parameters. 6. Developed a new procedure for predicting pressures due to live and dead loads on RCB culverts. 7. Analyzed load test data in accordance with the newly developed procedure. 8. Modified...

Brown, Dale Evan

1986-01-01

30

Corrugated micromachined membrane structures  

Microsoft Academic Search

Thin film copper membranes on silicon substrates were constructed using microelectronic fabrication techniques. Membranes possessed radial surface corrugation patterns. Membrane sizes ranged from 3.25 mm to 4 mm in diameter. A corrugation height of 10 ?m was chosen to maximize membrane flexibility. Two corrugation pitches were used; 200 ?m and 120 ?m. Double-sided lithography was used to ensure proper alignment

Dwayne D. Chrusch; C. Shafai

2002-01-01

31

Birefringent corrugated waveguide  

DOEpatents

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.

Moeller, Charles P. (Del Mar, CA)

1990-01-01

32

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

33

Incipient motion of gravel in a bottomless arch culvert  

Microsoft Academic Search

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

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

2011-01-01

34

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

Microsoft Academic Search

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

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

2011-01-01

35

Drainage culverts as habitat linkages and factors affecting passage by mammals  

Microsoft Academic Search

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

Anthony P. Clevenger; Bryan Chruszcz; Kari Gunson

2001-01-01

36

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

37

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

38

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

39

7. OBLIQUE VIEW OF CULVERT UNDER LATROBE ROAD WEST OF ...  

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

7. OBLIQUE VIEW OF CULVERT UNDER LATROBE ROAD WEST OF THE WHITE ROCK RD. INTERSECTION; VIEW TO SOUTHWEST. - Placerville Road, White Rock Road between Clarksville & White Rock, El Dorado Hills, El Dorado County, CA

40

Autonomous quadrotor unmanned aerial vehicle for culvert inspection  

E-print Network

This document presents work done to lay the foundation for an Unmanned Aerial Vehicle (UAV) system for inspecting culverts. By expanding upon prior progress creating an autonomous indoor quadrotor, many basic hardware and ...

Serrano, Nathan E

2011-01-01

41

7. EAST PORTAL OF CONCRETE LINED CULVERT LOCATED 30 YARDS ...  

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

7. EAST PORTAL OF CONCRETE LINED CULVERT LOCATED 30 YARDS WEST OF HAPPY ISLES BRIDGE. NOTE ROCK & CONCRETE FLOOR. - Happy Isles Bridge, Spanning Merced River on Service road, Yosemite Village, Mariposa County, CA

42

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

43

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

44

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

45

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

46

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

47

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

48

Using genetic programming to determine Che` zy resistance coefficient in corrugated channels  

E-print Network

Giustolisi Orazio Giustolisi Engineering Faculty of Taranto, Technical University of Bari, via Turismo no 8 channels. Three corrugated plastic pipes have been experimentally studied in order to generate data of corrugated channels. Finally, the work stresses the fact that the Genetic Programming hypothesis can

Fernandez, Thomas

49

Dealing with uncertainty when assessing fish passage through culvert road crossings  

USGS Publications Warehouse

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.

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

2012-01-01

50

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

SciTech Connect

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.

J. M. Capron

2008-04-15

51

35. Photo of concrete arch culvert constructed by Puget Sound ...  

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

35. Photo of concrete arch culvert constructed by Puget Sound Construction Company, 1911, for the Northern Pacific Railroad, over flume. Photo by Brian C. Morris, Puget Power, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

52

9. VIEW OF WHITE ROCK ROAD INDICATING CULVERT LOCATION (SEE ...  

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

9. VIEW OF WHITE ROCK ROAD INDICATING CULVERT LOCATION (SEE ROAD ANGLE POINT ON RIGHT) WITH LATROBE RD, INTERSECTION IN DISTANCE (LEFT OF CENTER); VIEW TO NORTHEAST. - Placerville Road, White Rock Road between Clarksville & White Rock, El Dorado Hills, El Dorado County, CA

53

Corrugated panel solar collector  

SciTech Connect

A two-sided solar collector is housed between a pair of opposed corrugated translucent plates which define a series of side by side elongated cavities. In alternate ones of the cavities are located integral elongated elastomeric solar energy absorbing elements including a series of side by side tubular conduits for heat transfer fluid and stretchable left and right margins terminated with beads that sealably engage the interiors of the empty cavities. A corrugated reflector below the solar collector reflects light passing through the empty cavities toward the cavities having the energy absorbing elements. The elongated solar energy absorbing elements may be configured as one such continuous element which is alternately run back and forth through the alternate cavities to form plural meandering fluid paths through the solar collector. Alternatively, interconnecting elements at the ends of the conduits are provided to define a fluid path passing serially through each conduit of each solar energy absorbing element.

Wasserman, K.J.

1981-10-06

54

An Improved Method of Manufacturing Corrugated Boxes: Lateral Corrugator  

SciTech Connect

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.

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

2008-12-18

55

Culvert Analysis Program Graphical User Interface 1.0--A preprocessing and postprocessing tool for estimating flow through culvert  

USGS Publications Warehouse

The peak discharge of a flood can be estimated from the elevation of high-water marks near the inlet and outlet of a culvert after the flood has occurred. This type of discharge estimate is called an “indirect measurement” because it relies on evidence left behind by the flood, such as high-water marks on trees or buildings. When combined with the cross-sectional geometry of the channel upstream from the culvert and the culvert size, shape, roughness, and orientation, the high-water marks define a water-surface profile that can be used to estimate the peak discharge by using the methods described by Bodhaine (1968). This type of measurement is in contrast to a “direct” measurement of discharge made during the flood where cross-sectional area is measured and a current meter or acoustic equipment is used to measure the water velocity. When a direct discharge measurement cannot be made at a streamgage during high flows because of logistics or safety reasons, an indirect measurement of a peak discharge is useful for defining the high-flow section of the stage-discharge relation (rating curve) at the streamgage, resulting in more accurate computation of high flows. The Culvert Analysis Program (CAP) (Fulford, 1998) is a command-line program written in Fortran for computing peak discharges and culvert rating surfaces or curves. CAP reads input data from a formatted text file and prints results to another formatted text file. Preparing and correctly formatting the input file may be time-consuming and prone to errors. This document describes the CAP graphical user interface (GUI)—a modern, cross-platform, menu-driven application that prepares the CAP input file, executes the program, and helps the user interpret the output

Bradley, D. Nathan

2013-01-01

56

Corrugation of roads  

NASA Astrophysics Data System (ADS)

We present a one dimensional model for the development of corrugations in roads subjected to compressive forces from a flux of cars. The cars are modeled as damped harmonic oscillators translating with constant horizontal velocity across the surface, and the road surface is subject to diffusive relaxation. We derive dimensionless coupled equations of motion for the positions of the cars and the road surface H( x, t), which contain two phenomenological variables: an effective diffusion constant ?( H) that characterizes the relaxation of the road surface, and a function a( H) that characterizes the plasticity or erodibility of the road bed. Linear stability analysis shows that corrugations grow if the speed of the cars exceeds a critical value, which decreases if the flux of cars is increased. Modifying the model to enforce the simple fact that the normal force exerted by the road can never be negative seems to lead to restabilized, quasi-steady road shapes, in which the corrugation amplitude and phase velocity remain fixed.

Both, Joseph A.; Hong, Daniel C.; Kurtze, Douglas A.

2001-12-01

57

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

USGS Publications Warehouse

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.

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

2011-01-01

58

Effect of corrugated characteristics on the liquid nitrogen temperature field of HTS cable  

NASA Astrophysics Data System (ADS)

In the high temperature superconducting (HTS) cable system, liquid nitrogen is usually chosen to be the coolant because of its low saturation temperature and large latent heat of vaporization. Thus, it is very important for superconducting cables that the liquid nitrogen temperature field keeps stable. However, the cryostat is usually made of flexible corrugated pipes and multi-layer insulation materials. The characteristics (e.g. wave pitch and wave depth) of corrugated pipes may have an effect on the heat exchange between cable and liquid nitrogen, even the whole temperature field of liquid nitrogen. In this paper, a two-dimensional model for 30 m long HTS cable has been modified to analyze the effect of corrugated characteristics on the temperature field of liquid nitrogen. The liquid nitrogen temperature difference between the outlet and the inlet of passage gradually increases as the wave pitch of the corrugated tube decreases and the wave depth increases.

Li, Z. M.; Li, Y. X.; Zhao, Y. Q.; Gao, C.; Qiu, M.; Chen, G. F.; Gong, M. Q.; Wu, J. F.

2014-01-01

59

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

60

Review on rail corrugation studies  

Microsoft Academic Search

In Japan, rail corrugations had not been so serious formerly, but it began to be prevailing in recent years. In order to prevent the generation of rail corrugation, many studies have been reported in the world since the end of 19th century, but theories on them have not explained the formation mechanism perfectly and no perfect countermeasures have been established

Yoshihiko Sato; Akira Matsumoto; Klaus Knothe

2002-01-01

61

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

2010-10-01

62

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

Microsoft Academic Search

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

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

2009-01-01

63

6. VIEW OF A RUSTED, HEAVYGAUGE METAL CULVERT (TY31776) PLACED ...  

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

6. VIEW OF A RUSTED, HEAVY-GAUGE METAL CULVERT (TY-3177-6) PLACED AT A SMALL DRAW WHERE KINGS CANYON ROAD WILL BE INSLOPED AND THE CULVERT WILL BE REMOVED. LOCATED AT MILEPOST 0.05 (ACCORDING TO THE ARCHAEOLOGICAL SITE RECORD FOR TY-3177). FACING SOUTH 76ø WEST (256ø). - Kings Canyon Road, Carson City, Carson City, NV

64

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

65

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

Microsoft Academic Search

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

David Park; Michael Sullivan; Erin Bayne; Garry Scrimgeour

2008-01-01

66

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...

67

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

ERIC Educational Resources Information Center

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. Experimental studies usually…

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

2011-01-01

68

Aeroacoustics of the swinging corrugated tube: voice of the Dragon.  

PubMed

When one swings a short corrugated pipe segment around one's head, it produces a musically interesting whistling sound. As a musical toy it is called a "Hummer" and as a musical instrument, the "Voice of the Dragon." The fluid dynamics aspects of the instrument are addressed, corresponding to the sound generation mechanism. Velocity profile measurements reveal that the turbulent velocity profile developed in a corrugated pipe differs notably from the one of a smooth pipe. This velocity profile appears to have a crucial effect both on the non-dimensional whistling frequency (Strouhal number) and on the amplitude of the pressure fluctuations. Using a numerical model based on incompressible flow simulations and vortex sound theory, excellent predictions of the whistling Strouhal numbers are achieved. The model does not provide an accurate prediction of the amplitude. In the second part of the paper the sound radiation from a Hummer is discussed. The acoustic measurements obtained in a semi-anechoic chamber are compared with a theoretical radiation model. Globally the instrument behaves as a rotating (Leslie) horn. The effects of Doppler shift, wall reflections, bending of the tube, non-constant rotational speed on the observed frequency, and amplitude are discussed. PMID:22280698

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

2012-01-01

69

Transient disturbance growth in a corrugated channel  

NASA Astrophysics Data System (ADS)

Transient growth of small disturbances may lead to the initiation of the laminar turbulent transition process. Such growth in a two-dimensional laminar flow in a channel with a corrugated wall is analysed. The corrugation has a wavy form that is completely characterized by its wavenumber and amplitude. The maximum possible growth and the form of the initial disturbance that leads to such growth have been identified for each form of the corrugation. The form that leads to the largest growth for a given corrugation amplitude, i.e. the optimal corrugation, has been found. It is shown that the corrugation acts as an amplifier for disturbances that are approximately optimal in the smooth channel case but has little effect in the other cases. The interplay between the modal (asymptotic) instability and the transient growth, and the use of the variable corrugation for modulation of the growth are discussed.

Szumbarski, J.; Floryan, J. M.

2006-12-01

70

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

Microsoft Academic Search

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,

Trevor A. Kinley; Nancy J. Newhouse

2009-01-01

71

Corrugated Membrane Fuel Cell Structures  

SciTech Connect

One of the most challenging aspects of traditional PEM fuel cell stacks is the difficulty achieving the platinum catalyst utilization target of 0.2 gPt/kWe set forth by the DOE. Good catalyst utilization can be achieved with state-of-the-art catalyst coated membranes (CCM) when low catalyst loadings (<0.3 mg/cm2) are used at a low current. However, when low platinum loadings are used, the peak power density is lower than conventional loadings, requiring a larger total active area and a larger bipolar plate. This results in a lower overall stack power density not meeting the DOE target. By corrugating the fuel cell membrane electrode structure, Ion Power?s goal is to realize both the Pt utilization targets as well as the power density targets of the DOE. This will be achieved by demonstrating a fuel cell single cell (50 cm2) with a twofold increase in the membrane active area over the geometric area of the cell by corrugating the MEA structure. The corrugating structure must be able to demonstrate the target properties of < 10 mOhm-cm2 electrical resistance at > 20 psi compressive strength over the active area, in combination with offering at least 80% of power density that can be achieved by using the same MEA in a flat plate structure. Corrugated membrane fuel cell structures also have the potential to meet DOE power density targets by essentially packaging more membrane area into the same fuel cell volume as compared to conventional stack constructions.

Grot, Stephen [President, Ion Power Inc.] President, Ion Power Inc.

2013-09-30

72

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

SciTech Connect

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.

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

1989-08-15

73

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...

74

Biaxially corrugated flexible sheet material  

DOEpatents

A flexible biaxially corrugated sheet material is formed from a plurality of identical trapezium segments which are arranged in a plurality of long strips a single segment wide. Adjacent strips are mirror images of each other and connected along adjoining sides with the angles of the four corners of adjacent segments being alternately less than 360.degree. and greater than 360.degree. along the length of a strip such that the sheet material has an undulating configuration, and is inherently curved and cannot lie in a flat plane.

Schmertz, John C. (5308 Ellsworth Ave., Pittsburgh, PA 15232)

1991-04-16

75

Bioinspired Corrugated Airfoil at Low Reynolds Numbers  

E-print Network

. A number of insects, including locusts, dragonflies, and damselflies, employ wings that are not smooth. However, several studies on corrugated dragonfly wings in steady flow or gliding flight [4­17] have led to a surprising conclusion: a corrugated dragonfly wing could have comparable or even better aerodynamic

Hu, Hui

76

Corrugated Limiting Tab for Jet Mixing  

NASA Astrophysics Data System (ADS)

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.

Kaushik, Mrinal; Rathakrishnan, E.

2013-12-01

77

Mechanical Analysis of Trapezoidal Corrugated Composite Skins  

NASA Astrophysics Data System (ADS)

Using of the corrugated skins and morphing technology is a good idea to provide the desired performance and improve aerodynamic efficiency. Corrugated structures and skins are flexible in the direction of corrugation and stiff in the transverse direction. In this paper a simple analytical model for the effective stiffness of the trapezoidal corrugated composites is developed in symmetrical and unsymmetrical lay-up. The elongation and effective stiffness in longitudinal and transverse directions of trapezoidal corrugated skins and flat composites are extracted using strain energy and Castiglione's theorem. Various dimensions of trapezoidal element for unidirectional and plain woven fabrics of E-glass/Epoxy are investigated. Trapezoidal corrugated composites were modelled by commercial FEM software ABAQUS and compared to analytical model. Analytical model is validated by experimental results from bending and tensile tests. Finally, load-displacement curves in the tensile and bending tests are studied and their different stages of behavior are identified. Results of FEM, experimental and analytical simulation show that how the corrugated composite skins can afford obviously larger deformation than the flat one and they are good solution to use in the morphing applications.

Ghabezi, P.; Golzar, M.

2013-08-01

78

Permeability of roads and railways to vertebrates: The importance of culverts  

Microsoft Academic Search

The movement of vertebrates through 17 culverts under roads and railways in Central Spain was analysed over the course of an annual cycle. Passage was detected for amphibians, lizards, snakes, small mammals, rats, hedgehogs, rabbits and several species of carnivorous mammals, including Felis sylvestris and Genetta genetta. The intensity of animal movement, which varied considerably among the groups, was influenced

Miguel Yanes; José M. Velasco; Francisco Suárez

1995-01-01

79

Effects of Culverts on Stream Fish Assemblages in the Alberta Foothills  

Microsoft Academic Search

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

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

2012-01-01

80

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

E-print Network

of a design flood while maintaining the required free board. Literature has noticed the lack of sedimentCulvert Design for Flood Routing considering Sediment Transport W.J. Rahmeyer PhD.1 and W Education Utah State University Brigham City, UT 84302 UNITED STATES OF AMERICA Abstract: Current flood

Rahmeyer, William J.

81

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

NASA Astrophysics Data System (ADS)

*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).

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

2013-12-01

82

The characterization of tandem and corrugated wings  

NASA Astrophysics Data System (ADS)

Dragonfly wings have two distinct features: a tandem configuration and wing corrugation. Both features have been extensively studied with the aim to understand the superior flight performance of dragonflies. In this paper we review recent development of tandem and corrugated wing aerodynamics. With regards to the tandem configuration, this review will focus on wing/wing and wing/vortex interactions at different flapping modes and wing spacing. In addition, the aerodynamics of tandem wings under gusty conditions will be reviewed and compared with isolated wings to demonstrate the gust resistance characteristics of flapping wings. Regarding corrugated wings, we review their structural and aerodynamic characteristics.

Lian, Yongsheng; Broering, Timothy; Hord, Kyle; Prater, Russell

2014-02-01

83

Method and apparatus for corrugating strips  

DOEpatents

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 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.

Day, Jack R. (Oak Ridge, TN); Curtis, Charles H. (Kingston, TN)

1983-01-01

84

Method and apparatus for corrugating strips  

DOEpatents

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.

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

1981-10-27

85

Fish Passage Effectiveness of Recently Constructed Road Crossing Culverts in the Puget Sound Region of Washington State  

Microsoft Academic Search

Fish passage barriers at road–stream crossings are widely recognized as salmon Oncorhynchus spp. habitat restoration priorities in Washington State and throughout the Pacific Northwest of the USA. More than 3,500 fish passage barriers (mostly culverts) have been repaired in Washington streams since 1999, costing more than US$139 million. We evaluated fish passage at 77 randomly selected culverts (new and repaired)

David M. Price; Timothy Quinn; Robert J. Barnard

2010-01-01

86

Open top culverts as an alternative drainage system to minimize ecological effects in earth roads.  

NASA Astrophysics Data System (ADS)

During the last fifteen years a research team from School of Forestry at the Technical University of Madrid (Spain) has developed several competitive research projects regarding forest roads and open top culverts. A first approach was established with a prototype of 7 meters length in a hydraulic channel at the laboratory determining main parameters of different open top culverts in relation to different sizes of gravels and the self washing properties relationship with different slopes up to 8 %. The curves obtained may help to properly install these drainage systems avoiding maintenance costs. In addition more targeted pilot studies were developed in different forest earth roads in center and north Spain. The construction of the stations under study was financed by the U.P.M and the R&D National Plan. The main outcomes relates the low variation of humidity in a 20 m. wide range at both sides of the open top culverts and several considerations relating the angle of installation, the spacing of such drainage systems and the benefits against rilling along the roads. Also the erosion produced downhill was established and some construction methods to avoid adverse ecological effects. The diffusion of results includes congresses and a small booklet with a great acceptance in forestry services. Also a patent (ES 2 262 437) of an advanced model has been registered.

García, Jose L.; Elorrieta, Jose; Robredo, Jose C.; García, Ricardo; García, Fernando; Gimenez, Martin C.

2013-04-01

87

A 2-GHz Rectangular Corrugated Horn  

SciTech Connect

We have designed, constructed and tested a large, rectangular horn antenna with a center frequency of 2.0 GHz, corrugated on the E-plane walls, made out of aluminum sheet. A new technique has been developed to solder thin aluminum strips onto the back plane to form the corrugations. The radiation beam pattern shows half-power beamwidths of 12{sup 0} and 14{sup 0} in the H and E planes respectively, and side lobe response below -40 dB at angles greater than 50{sup 0} from horn axis. The measured return loss is less than -20 dB (VSWR < 1.22) between 1.7 and 2.3 GHz; insertion loss is less than 0.15 dB.

Bersanelli, M.; Bensadoun, M.; De Amici, Giovanni; Limon, M.; Smoot, George F.; Tanaka, S.; Witebsky, C.; Yamada, J.

1991-10-01

88

Plasmonic corrugated cylinder-cone terahertz probe.  

PubMed

The spoof surface plasmon polariton (SPP) effect on the electromagnetic field distribution near the tip of a periodically corrugated metal cylinder-cone probe working at the terahertz regime was studied. We found that radially polarized terahertz radiation could be coupled effectively through a spoof SPP into a surface wave and propagated along the corrugated surface, resulting in more than 20× electric field enhancement near the tip of probe. Multiple resonances caused by the antenna effect were discussed in detail by finite element computation and theoretical analysis of dispersion relation for spoof SPP modes. Moreover, the key figures of merit such as the resonance frequency of the SPP can be flexibly tuned by modifying the geometry of the probe structure, making it attractive for application in an apertureless background-free terahertz near-field microscope. PMID:25121543

Yao, Haizi; Zhong, Shuncong

2014-08-01

89

Effects of corrugation of the dragonfly wing on gliding performance  

Microsoft Academic Search

We investigate the aerodynamic performance of the dragonfly wing, which has cross-sectional corrugation, via a static 2-dimensional unsteady simulation. Computational conditions are Re=150, 1400, and 10,000 with angles of attack ranging from 0° to 40°. From the computational results, lift coefficients are increased by the wing corrugation at all Reynolds number. However, the corrugation has little influence on the drag

Won-Kap Kim; Jin Hwan Ko; Hoon Cheol Park; Doyoung Byun

2009-01-01

90

Research and development of long heat pipes and their applications  

NASA Astrophysics Data System (ADS)

A 40 m thermosyphon type flexible corrugated heat pipe was constructed and its heat transfer characteristics were measured. The flooding phenomenon was quantitatively observed using electronic stethoscopes, and its influence to the heat transfer characteristics was determined. The particular features of the road heating system using long heat pipes are: (1) there is no possibility of water leaking and their maintenance is easy; (2) they endure heavy loads, thermal stresses, vibrations and ground subsidence; (3) the heat transfering surface area of the heat pipes is so large that it is particularly effective for heating through small temperature difference; and (4) the installation is easy and inexpensive.

Takaoka, M.; Mohtai, T.; Mochizuki, M.; Mashiko, K.

1984-03-01

91

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

Microsoft Academic Search

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

Stephan Peake

2004-01-01

92

Pipe Dreams.  

ERIC Educational Resources Information Center

Discusses the importance of attention to plumbing in college facilities, offering examples from various campuses. Addresses preventive maintenance, technology, and piping materials, including the debate between cast iron and PVC for drain pipes. (EV)

Milshtein, Amy

2002-01-01

93

Performance of zigzag corrugated furrows in Bolivia  

NASA Astrophysics Data System (ADS)

In Bolivia, irrigation area is estimated in more than 250000 ha, being surface irrigation the most common method. In highland areas (Altiplano) and in interandean valleys, traditional and ancestral irrigation systems such as flood irrigation, contour furrows, zigzag corrugated furrows, suka kollus and irrigation by kanis, are the most important. In the case of very steep terrains and shallow soils, the zigzag corrugated irrigation method is very frequent. This irrigation method has been used for a long time but their low application efficiency and the shortage of water justify this work devoted to their characterization and to study their performance. The experimental study was conducted southeast of the city of La Paz in the community of Cebollino located at 2600 meters above sea level. Furrow characteristics vary in function of crop type and soil slope, so that the larger the slope the greater the separation between furrows. In our case, the crop chosen was the lettuce and the experimental plot had an area of 800 m2 with a slope ranging between 14 and 18%. Blocks of corrugated furrows were identified and experimental measures were made during each irrigation, once per week, in the central blocks to avoid border effects. To determine advance curves 15 stations were used spaced 18 m. At each station, advance and recession time and infiltration depth were measured. Inlet and outlet flow were controlled each 5 min. To calculate the reference evapotranspiration, the Hargraves-Samani equation was used. Due to the very high terrain slopes, the advance curve takes a linear form rather than the typical exponential form. This hinders the proper calculation of the parameters of the Kostiakov-Lewis equation used to determine the infiltrated depth values. The inlet flow range, along irrigation events, between 0.01 and 0.085 L/s due to the uncontrolled use of water in fields located upstream. The large variability of inflow flow difficult irrigation management especially in regard to the system organization and operation.

Roldán Cañas, J.; Chipana, R.; Moreno-Pérez, M. F.; Chipana, G.

2012-04-01

94

Aerodynamic Performances of Corrugated Dragonfly Wings at Low Reynolds Numbers  

Microsoft Academic Search

The cross-sections of dragonfly wings have well-defined corrugated configurations, which seem to be not very suitable for flight according to traditional airfoil design principles. However, previous studies have led to surprising conclusions of that corrugated dragonfly wings would have better aerodynamic performances compared with traditional technical airfoils in the low Reynolds number regime where dragonflies usually fly. Unlike most of

Masatoshi Tamai; Guowei He; Hui Hu

2006-01-01

95

A linear model for the corrugation of rails  

Microsoft Academic Search

A linear model for the corrugation of rails is described. The study of a transfer function between the initial wheel and rail roughness and the wear rate spectra in the contact patch is presented. Under some conditions, depending on mean creepages, wheelset and track parameters, the initial roughness on the rail is shown to degenerate into corrugation in some frequency

E. Tassilly; N. Vincent

1991-01-01

96

Disappointment and regret enhance corrugator reactivity in a gambling task.  

PubMed

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

Wu, Yin; Clark, Luke

2015-04-01

97

Scalar Casimir-Polder forces for uniaxial corrugations  

E-print Network

We investigate the Dirichlet-scalar equivalent of Casimir-Polder forces between an atom and a surface with arbitrary uniaxial corrugations. The complexity of the problem can be reduced to a one-dimensional Green's function equation along the corrugation which can be solved numerically. Our technique is fully nonperturbative in the height profile of the corrugation. We present explicit results for experimentally relevant sinusoidal and sawtooth corrugations. Parameterizing the deviations from the planar limit in terms of an anomalous dimension which measures the power-law deviation from the planar case, we observe up to order-one anomalous dimensions at small and intermediate scales and a universal regime at larger distances. This large-distance universality can be understood from the fact that the relevant fluctuations average over corrugation structures smaller than the atom-wall distance.

Babette Döbrich; Maarten DeKieviet; Holger Gies

2008-10-20

98

Corrugated Quantum Well Infrared Photodetectors and Arrays  

NASA Technical Reports Server (NTRS)

Quantum well infrared photodetectors (QWIPs) have many advantages in infrared detection, mainly due to the mature Ill-V material technology. The employment of the corrugation structure further advances the technology by providing a simple, yet efficient light-coupling scheme. A C-QWIP enjoys the same flexibility as a detector with intrinsic normal incident absorption. In this paper, we will discuss the utilities of C-QWIPs in different applications, including two-color detection and polarization-sensitive detection. Besides practical applications, C-QWIPs are also useful in detector characterization. They can be used for measuring the absorption coefficient of light propagating parallel to the layers under bias and providing information on the energy resolved photoconductive gain. These two quantities have never been measured before. Based on the corrugation design, we have made several modifications that further improve the detector sensitivity without increasing its complexity. Other than the C-QWIP structure, we also continue searching for other sensitive detector architectures. In a quantum grid infrared photodetector, 3-dimensional electron confinement can be achieved, with which the detector is able to absorb light in all directions. At the same time, the photoconductive gain can also be improved. We further improve the design using a blazed structure. All the experimental results are supported by a rigorous electromagnetic modal transmission-line theory developed especially for these types of structures. Preliminary thermal imaging using C-QWIP FPAs validates the advantages of the present approach.

Choi, K. K.; Chen, C. J.; Rohkinson, L. P.; Das, N. C.; Jhabvala, M.

1999-01-01

99

Biased Brownian motion in extremely corrugated tubes.  

PubMed

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

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

2011-12-01

100

Corrugation Profile for the Quasioptical Polarization Separator  

NASA Astrophysics Data System (ADS)

We consider and classify the regime of separation of two orthogonally polarized E and H waves by using a reflecting metal diffraction grating, which sends all the energy of an incident wave with one polarization to the specular order of diffraction, and that of an incident wave with the other polarization, to the (-1)st order of diffraction (in this case, the autocollimation regime is used). The conditions of existence of such a regime are studied in the simplest cases (generalization of the approach presented in [1, 2] to the case of a sinusoidal surface), along with the possibility to construct more complex (nonsinusoidal) corrugation profiles, for which the specified regime has certain advantages, e.g., a wider bandwidth. Examples of such profiles are presented. The studies are performed on the basis of numerical solution of the problem of diffraction of a plane electromagnetic wave by a perfectly conducting corrugated surface within the framework of the integral-equation method employing the authors' computer visualization code.

Koposova, E. V.; Lubyako, L. V.

2014-07-01

101

Water electrolyte transport through corrugated carbon nanopores  

NASA Astrophysics Data System (ADS)

We investigate the effect of wall roughness on water electrolyte transport characteristics at different temperatures through carbon nanotubes by using nonequilibrium molecular dynamics simulations. Our results reveal that shearing stress and the nominal viscosity increase with ion concentration in corrugated carbon nanotubes (CNTs), in contrast to cases in smooth CNTs. Also, the temperature increase leads to the reduction of shearing stress and the nominal viscosity at moderate degrees of wall roughness. At high degrees of wall roughness, the temperature increase will enhance radial movements and increases resistance against fluid motion. As the fluid velocity increases, the particles do not have enough time to fully adjust their positions to minimize system energy, which causes shearing stress and the nominal viscosity to increase. By increasing roughness amplitude or decreasing roughness wavelength, the shearing stress will increase. Synergistic effects of such parameters (wall roughness, velocity, ion concentration, and temperature) inside corrugated CNTs are studied and compared with each other. The molecular mechanisms are considered by investigating the radial density profile and the radial velocity profile of confined water inside modified CNT.

Moghimi Kheirabadi, A.; Moosavi, A.

2014-07-01

102

Comparison of test results for flat plate, transpired flat plate, corrugated, and transpired corrugated solar air heaters  

NASA Astrophysics Data System (ADS)

Results from tests to demonstrate technical improvements from transpiring and/or corrugating a selective black absorber plate solar air collector are reported. A literature review is presented, and the specific working components of transpired and nontranspired flat and corrugated absorbers are provided, including transpiration through slots, a microperforated plate, a corrugated plate, and a transpired, slotted, corrugated plate. Inlet and outlet temperatures were monitored, and inlet air was controlled, with trials covering temperatures of 38, 60, 82, and 104 C to test the effect of maintaining the fluid temperature close to the collector temperature. No differences were observed in running the collectors with corrugations vertically instead of horizontally, and the collector with transpiration through slots was found to display the lowest pressure drop.

Rhee, S. J.; Edwards, D. K.

1981-11-01

103

Heat Pipes  

NASA Technical Reports Server (NTRS)

Phoenix Refrigeration Systems, Inc.'s heat pipe addition to the Phoenix 2000, a supermarket rooftop refrigeration/air conditioning system, resulted from the company's participation in a field test of heat pipes. Originally developed by NASA to control temperatures in space electronic systems, the heat pipe is a simple, effective, heat transfer system. It has been used successfully in candy storage facilities where it has provided significant energy savings. Additional data is expected to fully quantify the impact of the heat pipes on supermarket air conditioning systems.

1991-01-01

104

Thermal Stability of Corrugated Epitaxial Graphene Grown on Re(0001)  

NASA Astrophysics Data System (ADS)

We report on a novel approach to determine the relationship between the corrugation and the thermal stability of epitaxial graphene grown on a strongly interacting substrate. According to our density functional theory calculations, the C single layer grown on Re(0001) is strongly corrugated, with a buckling of 1.6 Å, yielding a simulated C 1s core level spectrum which is in excellent agreement with the experimental one. We found that corrugation is closely knit with the thermal stability of the C network: C-C bond breaking is favored in the strongly buckled regions of the moiré cell, though it requires the presence of diffusing graphene layer vacancies.

Miniussi, E.; Pozzo, M.; Baraldi, A.; Vesselli, E.; Zhan, R. R.; Comelli, G.; Mente?, T. O.; Niño, M. A.; Locatelli, A.; Lizzit, S.; Alfè, D.

2011-05-01

105

Diverse corrugation pattern in radially shrinking carbon nanotubes  

SciTech Connect

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.

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

106

Fatigue testing of corrugated and Teflon hoses  

NASA Technical Reports Server (NTRS)

Single and two-phase heat transport systems for the thermal control of large space facilities require fluid lines that traverse joints and either rotate or move in some other manner. Flexible hoses are being considered as one means of traversing these joints. To test the resilience of flexible hoses to bending stress, a test assembly was constructed to determine the number of flexing cycles the hoses could withstand before losing their ability to maintain a constant pressure. Corrugated metal hoses and Teflon hoses were tested at different pressures with nitrogen gas. The metal hoses had lives ranging from 30,000 to 100,000 flexing cycles. But, even after 400,000 cycles, the Teflon hoses remained essentially intact, though some leakage in the convoluted Teflon is noted.

Benner, Steve M.; Swanson, Theodore D.; Costello, Frederick A.

1990-01-01

107

Piping Plover  

USGS Multimedia Gallery

Chicks and eggs of piping plovers. The piping plover is a small migratory shorebird listed as endangered in Canada and the U.S. Great Lakes, and threatened throughout the remainder of its U.S. breeding and winter range. Recent surveys indicate that there are only about 8,000 adults in existence.  Th...

108

Piping Plover  

USGS Multimedia Gallery

An adult piping plover. The piping plover is a small migratory shorebird listed as endangered in Canada and the U.S. Great Lakes, and threatened throughout the remainder of its U.S. breeding and winter range. Recent surveys indicate that there are only about 8,000 adults in existence. The USGS is co...

109

7. DETAIL VIEW UNDER BRIDGE OF CORRUGATED STEEL, BEAMS, RODS, ...  

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

7. DETAIL VIEW UNDER BRIDGE OF CORRUGATED STEEL, BEAMS, RODS, AND ABUTMENT - Price River Bridge, Spanning Price River, 760 North Street in Carbonville, 1 mile northwest of Price, Carbonville, Carbon County, UT

110

Prediction of sound reflection by corrugated porous surfaces.  

PubMed

The coupled mode (CM) and finite-element methods (FEMs) are developed and used to predict the acoustic reflection coefficient of a semi-infinite porous medium with closely spaced two-dimensional (2D) periodical corrugations. These methods are also applied to predict the reflection coefficient of a periodic array of porous corrugations installed on an acoustically rigid surface. It is shown that the predictions by the both methods agree closely. The reflection coefficient and Brewster angle of total refraction for the corrugated semi-infinite medium predicted with these methods are compared against that predicted by the Biot/Tolstoy/Howe/Twersky and extended Twersky models. A similar analysis is carried out for porous corrugations set on a rigid backing. The behavior of the reflection coefficient and the pole in the expression for the reflection coefficient located close to grazing incidence is studied. PMID:21476627

Allard, J-F; Dazel, O; Gautier, G; Groby, J-P; Lauriks, W

2011-04-01

111

Piping Flexibility  

NASA Technical Reports Server (NTRS)

A NASA computer program aids Hudson Engineering Corporation, Houston, Texas, in the design and construction of huge petrochemical processing plants like the one shown, which is located at Ju'aymah, Saudi Arabia. The pipes handling the flow of chemicals are subject to a variety of stresses, such as weight and variations in pressure and temperature. Hudson Engineering uses a COSMIC piping flexibility analysis computer program to analyze stresses and unsure the necessary strength and flexibility of the pipes. This program helps the company realize substantial savings in reduced engineering time.

1978-01-01

112

Piping Analysis  

NASA Technical Reports Server (NTRS)

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.

1980-01-01

113

Corrugated QWIP array fabrication and characterization  

NASA Astrophysics Data System (ADS)

A corrugated quantum well IR photodetector (C-QWIP) focal plane array (FPA) with cutoff at 11.2 micrometers has been fabricated and characterized. The C-QWIP array uses total internal reflection to couple normal incident light into the pixels. The processing steps involve only one chemical etching, one optional reactive ion etching, and one ohmic contact metalization. The detector array has 256 X 256 pixel elements, indium bumped to a direct injection readout circuit. The photocurrent to dark current ratio measured in this FPA, on which the noise equivalent temperature difference depends, is consistent with that of a large area test sample. The array shows good responsivity uniformity of 5.2 percent with no extra leakage resulted from array processing. The estimated noise equivalent temperature difference of this array, excluding the readout noise, is 17 mK at T equals 63 K. The fact that this FPA can be operated at a temperature similar to those of standard QWIP arrays with much shorter wavelengths shows that the C-QWIP structure can greatly increase array performance.

Choi, Kwong-Kit; Goldberg, Arnold C.; Das, Naresh C.; Jhabvala, Murzy D.; Bailey, Robert B.; Vural, Kadri

1998-04-01

114

Dynamics of a dense gravity current flowing over a corrugation  

NASA Astrophysics Data System (ADS)

In this study, we investigate the dynamics of a dense gravity currents over different sizes of ridges and canyons. We employ a high resolution idealized isopycnal model and perform a large number of experiments changing the aspect ratio of a ridge/canyon, the Coriolis parameter, the reduced gravity, the background slope and initial overflow thickness. The control run (smooth topography) is in an eddy-regime and the frequencies of the eddies coincide with those of the Filchner overflow ( Darelius et al., 2009). Our idealized corrugation experiments show that corrugations steer the plume downslope, and that ridges are more effective than canyons in transporting the overflow to the deep ocean. We find that a corrugation Burger number ( Buc) can be used as a parameter to describe the flow over topography. Buc is a combination of a Froude number and the aspect ratio. The maximum downslope transport of a corrugation can be increased when the height of the corrugation increases ( Buc increases) or when the width of the corrugation decreases ( Buc increases). In addition, we propose a new parameterization of mixing as a function of Buc that can be used to account for unresolved shear in coarse resolution models. The new parameterization captures the increased local shear, thus increasing the turbulent kinetic energy and decreasing the gradient Richardson number. We find reasonable agreement in the overflow thickness and transport between the models with this parameterization and the high resolution models. We conclude that mixing effects of corrugations can be implemented as unresolved shear in an eddy diffusivity formulation and this parameterization can be used in coarse resolution models.

Il?cak, Mehmet; Legg, Sonya; Adcroft, Alistair; Hallberg, Robert

115

Aerodynamic Performances of Corrugated Dragonfly Wings at Low Reynolds Numbers  

NASA Astrophysics Data System (ADS)

The cross-sections of dragonfly wings have well-defined corrugated configurations, which seem to be not very suitable for flight according to traditional airfoil design principles. However, previous studies have led to surprising conclusions of that corrugated dragonfly wings would have better aerodynamic performances compared with traditional technical airfoils in the low Reynolds number regime where dragonflies usually fly. Unlike most of the previous studies of either measuring total aerodynamics forces (lift and drag) or conducting qualitative flow visualization, a series of wind tunnel experiments will be conducted in the present study to investigate the aerodynamic performances of corrugated dragonfly wings at low Reynolds numbers quantitatively. In addition to aerodynamics force measurements, detailed Particle Image Velocimetry (PIV) measurements will be conducted to quantify of the flow field around a two-dimensional corrugated dragonfly wing model to elucidate the fundamental physics associated with the flight features and aerodynamic performances of corrugated dragonfly wings. The aerodynamic performances of the dragonfly wing model will be compared with those of a simple flat plate and a NASA low-speed airfoil at low Reynolds numbers.

Tamai, Masatoshi; He, Guowei; Hu, Hui

2006-11-01

116

Detection of rail corrugation based on fiber laser accelerometers  

NASA Astrophysics Data System (ADS)

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.

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

2013-09-01

117

Heat Pipes  

NASA Technical Reports Server (NTRS)

Bobs Candies, Inc. produces some 24 million pounds of candy a year, much of it 'Christmas candy.' To meet Christmas demand, it must produce year-round. Thousands of cases of candy must be stored a good part of the year in two huge warehouses. The candy is very sensitive to temperature. The warehouses must be maintained at temperatures of 78-80 degrees Fahrenheit with relative humidities of 38- 42 percent. Such precise climate control of enormous buildings can be very expensive. In 1985, energy costs for the single warehouse ran to more than $57,000 for the year. NASA and the Florida Solar Energy Center (FSEC) were adapting heat pipe technology to control humidity in building environments. The heat pipes handle the jobs of precooling and reheating without using energy. The company contacted a FSEC systems engineer and from that contact eventually emerged a cooperative test project to install a heat pipe system at Bobs' warehouses, operate it for a period of time to determine accurately the cost benefits, and gather data applicable to development of future heat pipe systems. Installation was completed in mid-1987 and data collection is still in progress. In 1989, total energy cost for two warehouses, with the heat pipes complementing the air conditioning system was $28,706, and that figures out to a cost reduction.

1990-01-01

118

Lateral Casimir force between deeply corrugated dielectric and metallic plates  

E-print Network

We study the lateral Casimir force between corrugated dielectric plates. We use the dielectric contrast perturbation theory [R. Golestanian, {\\it Phys. Rev. Lett.} {\\bf 95}, 230601, (2005)], which allows us to consider arbitrary deformations with large amplitudes. We consider sinusoidal, rectangular, and sawtooth corrugations, for samples made of silicon and gold. We use the plasma and Drude-Lorentz models for the permittivity of gold and silicon, respectively. For these geometries and materials, the lateral Casimir force is {\\it not} a sinusoidal function of the relative lateral displacement of plates when the gap between the plates in comparable with the depth of the corrugations. Our results facilitate the design of miniaturized devices based on lateral Casimir forces.

Arash Azari; MirFaez Miri

2014-09-16

119

Lateral Casimir Force Between Deeply Corrugated Dielectric and Metallic Plates  

NASA Astrophysics Data System (ADS)

We study the lateral Casimir force between corrugated dielectric plates. We use the dielectric contrast perturbation theory [R. Golestanian, Phys. Rev. Lett. 95, 230601, (2005)], which allows us to consider arbitrary deformations with large amplitudes. We consider sinusoidal, rectangular, and sawtooth corrugations, for samples made of silicon and gold. We use the plasma and Drude-Lorentz models for the permittivity of gold and silicon, respectively. For these geometries and materials, the lateral Casimir force is not a sinusoidal function of the relative lateral displacement of plates when the gap between the plates in comparable with the depth of the corrugations. Our results facilitate the design of miniaturized devices based on lateral Casimir forces.

Azari, Arash; Miri, Mirfaez

120

Aerothermodynamic Assessment of Corrugated Panel Thermal Protection Systems  

NASA Technical Reports Server (NTRS)

The feasibility of using corrugated panels as a thermal protection system for an advanced space transportation vehicle was investigated. The study consisted of two major tasks: development of improved correlations for wind tunnel heat transfer and pressure data to yield design techniques, and application of the design techniques to determine if corrugated panels have application future aerospace vehicles. A single-stage-to-orbit vehicle was used to assess advantages and aerothermodynamic penalties associated with use of such panels. In the correlation task, experimental turbulent heat transfer and pressure data obtained on corrugation roughened surfaces during wind tunnel testing were analyzed and compared with flat plate data. The correlations and data comparisons included the effects of a large range of geometric, inviscid flow, internal boundary layer, and bulk boundary layer parameters in supersonic and hypersonic flow.

Brandon, H. J.; Britt, A. H.; Kipp, H. W.; Masek, R. V.

1978-01-01

121

Equivalent models of corrugated laminates for morphing skins  

NASA Astrophysics Data System (ADS)

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.

Xia, Yuying; Friswell, Michael I.

2011-03-01

122

Heat Pipes  

NASA Technical Reports Server (NTRS)

Heat Pipes were originally developed by NASA and the Los Alamos Scientific Laboratory during the 1960s to dissipate excessive heat build- up in critical areas of spacecraft and maintain even temperatures of satellites. Heat pipes are tubular devices where a working fluid alternately evaporates and condenses, transferring heat from one region of the tube to another. KONA Corporation refined and applied the same technology to solve complex heating requirements of hot runner systems in injection molds. KONA Hot Runner Systems are used throughout the plastics industry for products ranging in size from tiny medical devices to large single cavity automobile bumpers and instrument panels.

1996-01-01

123

Piping Connector  

NASA Technical Reports Server (NTRS)

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.

1994-01-01

124

Double-Corrugated Rectangular Waveguide Slow-Wave Structure for Terahertz Vacuum Devices  

Microsoft Academic Search

A novel rectangular-corrugated waveguide is proposed for submillimeter and terahertz vacuum devices. Two parallel corrugations that are enclosed in a rectangular waveguide create a beam channel that supports an interaction with a cylindrical electron beam. A notable advantage of the double-corrugated rectangular waveguide slow-wave structure (SWS) is the extension of well-established cylindrical beam technology to corrugated waveguide SWSs. The structure

Mauro Mineo; Claudio Paoloni

2010-01-01

125

Acoustic radiation efficiency of a periodically corrugated rigid piston  

NASA Astrophysics Data System (ADS)

The radiation of sound by a periodically corrugated rigid piston is explored using theoretical and numerical approaches and compared with the radiation of flat rigid piston. The depth and the period of the corrugation are considered to be comparable with the wavelength in the surrounding fluid. Radiation enhancement is predicted due to cavity resonances and coherent diffraction. In addition, broad regions of low radiation efficiency are observed. Both effects could have an impact in acoustic transducers technology, either to increase the piston radiated power or to create a source of evanescent acoustic waves. The possibilities offered by this strategy in the nonlinear acoustic regime are also briefly discussed.

Estrada, Héctor; Uris, Antonio; Meseguer, Francisco

2012-09-01

126

Performance of advanced corrugated-duct solar air collector compared with five conventional designs  

Microsoft Academic Search

This paper presents the results of the experimental investigation and performance analysis of an advanced corrugated duct solar collector. The collector (air heater) is constructed of corrugated surfaces similar to those used for compact heat exchangers, with the air flowing normal to the corrugations. The collector is compared with five other conventional designs constructed and tested during the course of

M. N. Metwally; H. Z. Abou-Ziyan; A. M. El-Leathy

1997-01-01

127

Bag Pipe  

NSDL National Science Digital Library

In this activity, learners explore sound by constructing their very own bagpipe instrument. Learners use PVC pipe, a ziploc bag, rubber tubing, rubber bands, a plastic bottle, and a rubber glove to build their bagpipe. Note: a drill is required, but is not included in the cost of materials.

Environmental Science Workshop

2011-01-01

128

Pipe connector  

Microsoft Academic Search

A safety test facility for testing sodium-cooled nuclear reactor components includes a reactor vessel and a heat exchanger submerged in sodium in the tank. The reactor vessel and heat exchanger are connected by an expansion\\/deflection pipe coupling comprising a pair of coaxially and slidably engaged tubular elements having radially enlarged opposed end portions of which at least a part is

Thomas E. Sullivan; John A. Pardini

1978-01-01

129

Corrugated Membrane Fuel Cell 2010 DOE Hydrogen Program Fuel Cell  

E-print Network

Corrugated Membrane Fuel Cell Structures Structures 2010 DOE Hydrogen Program Fuel Cell 2010 DOE Hydrogen Program Fuel Cell Project Kick-Off Principle Investigator: Dr. Stephen Grot Presenter: Dr structure Compared to MEA in a flat plate structure 9 #12;Technical Accomplishments Titanium Screen as Gas

130

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...

131

Test of superplastically formed corrugated aluminum compression specimens with beaded webs  

NASA Technical Reports Server (NTRS)

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.

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

1991-01-01

132

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

USGS Publications Warehouse

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.

Hurley, N.M., Jr.

1996-01-01

133

Buried pipe design  

Microsoft Academic Search

This book covers basic information on proper, cost-effective design of buried-pipe systems for underground fluid transportation. Examines various pipe products available. Discusses soil engineering and piping mechanics. Specific topics include pipe-wall stresses and strains; design bases; rigid- and flexible-pipe analysis; soil pressure; and longitudinal, wheel, expansive-soil, and frost loading.

Mosler

1990-01-01

134

Corrugated outer sheath gas-insulated transmission line  

DOEpatents

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.

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

1981-01-01

135

Cooling performance of heat sinks with corrugated-fins  

Microsoft Academic Search

Heat sinks with corrugated fins have been developed for effective cooling of large-scale integrated circuit (LSI) packages. These heat sinks are so light that they are suitable for cooling small and light LSI packages with low\\/high heat generation, e.g. quad flat package (QFP), ball grid array (BGA) package, chip scale package (CSP), etc., which are contributing to the downsizing of

Masahito Tasaka; Kenjiro Shinohara; Chihiro Hayashi; Shoichi Kashima; Ken Koyama

1998-01-01

136

Optimization of the leading edge segment of a corrugated wing  

NASA Astrophysics Data System (ADS)

Insect wings consist of flat plates of membranes stiffened by spars. The effect of this structure is that the wings appear as corrugated surfaces when considered on chordwise sections. We know that aerodynamically efficient insects such as a dragonfly engage in fixed wing flight modes for extended periods. The analysis in the literature has shown that the aerodynamic efficiency (cl/cd) of a corrugated aerofoil is sensitive to Reynolds number (Re) and angle-of-attack (AoA), yet the conclusions established are on the basis of flow analysis on a single baseline shape only. The sample size of the aerofoils must be extended further so that the influence and merits of corrugated shape features can be established. In this work, a design-of-experiments (DoE) approach is applied to induce systematic shape perturbations on a select, off-the-shelf baseline shape one feature at a time over a set number of increments. At each shape increment, the aerodynamic forces are established using a high fidelity CFD solver. The design space is modeled at a Re of 20,000 and 34,000 and at flow angle of 4.0° to represent a Micro Air Vehicle (MAV) in glide. The results confirmed the importance of the leading and trailing edge deflections on cl/cd. At Re = 20, 000, cl/cd of a corrugated aerofoil with deflection at the leading edge region only is 16% higher than the baseline shape, and 39% higher than the flat plate. At Re = 34, 000, cl/cd performance is sensitive to the trailing edge deflection. At the optimum deflection setting, cl/cd is 18% higher than the baseline shape and 23% higher than the flat plate. The results confirm that the leading and trailing edge deflections are critical to cl/cd for a MAV in glide.

Khurana, Manas; Chahl, Javaan

2014-03-01

137

Optimization of a corrugated stiffened composite panel under uniaxial compression  

NASA Technical Reports Server (NTRS)

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.

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

1973-01-01

138

Transient coexisting nanophases in ultrathin films confined between corrugated walls  

SciTech Connect

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.

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

139

Interaction of streamers and stationary corrugated ionization waves in semiconductors.  

PubMed

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

Kyuregyan, A S

2014-04-01

140

Non-contact gears: II. Casimir torque between concentric corrugated cylinders for the scalar case  

E-print Network

The Casimir interaction between two concentric corrugated cylinders provides the mechanism for non-contact gears. To this end, we calculate the Casimir torque between two such cylinders, described by $\\delta$-potentials, which interact through a scalar field. We derive analytic expressions for the Casimir torque for the case when the corrugation amplitudes are small in comparison to the corrugation wavelengths. We derive explicit results for the Dirichlet case, and exact results for the weak coupling limit, in the leading order. The results for the corrugated cylinders approach the corresponding expressions for the case of corrugated parallel plates in the limit of large radii of cylinders (relative to the difference in their radii) while keeping the corrugation wavelength fixed.

Ines Cavero-Pelaez; Kimball A. Milton; Prachi Parashar; K. V. Shajesh

2008-07-03

141

Heat transfer characteristics of a back-corrugated absorber surface for solar air collectors  

Microsoft Academic Search

The present study experimentally examines a back-corrugated absorber-convector comprised of a rectangularly corrugated plate attached to the back side of a flat absorber plate with a high temperature, high strength adhesive. The upper surface is subjected to a heat flux from a blanket-type electric heater simulating solar irradiation. The corrugated plate configuration creates two parallel airflow channel types. The two

K. A. Shockey; J. T. Pearson; D. P. Dewitt

1981-01-01

142

On the control of the lateral Casimir force between corrugated surfaces  

E-print Network

The general perturbative expression for the lateral Casimir force between two plates covered by longitudinal corrugations of arbitrary shape is obtained. This expression is applicable for corrugation periods larger than the separation distance. The cases of asymmetric corrugations are considered, which allow to increase the maximum to minimum force ratio and affect the character of equilibrium points. This opens new opportunities to control the lateral Casimir forces for use in microelectromechanical devices based entirely on the vacuum fluctuation properties.

E. V. Blagov; G. L. Klimchitskaya; U. Mohideen; V. M. Mostepanenko

2004-07-20

143

Experimental Investigation of the Strength of Multiweb Beams with Corrugated Webs  

NASA Technical Reports Server (NTRS)

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.

Fraser, Allister F

1956-01-01

144

40 CFR 246.202-2 - Recommended procedures: Corrugated container recovery from smaller commercial facilities.  

Code of Federal Regulations, 2010 CFR

...procedures: Corrugated container recovery from smaller commercial facilities. 246.202-2 Section... SOURCE SEPARATION FOR MATERIALS RECOVERY GUIDELINES Requirements...from smaller commercial facilities. The recovery of...

2010-07-01

145

Open-ended Coaxial Cavities with Corrugated Inner and Outer Walls  

NASA Astrophysics Data System (ADS)

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.

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

2015-03-01

146

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

NASA Astrophysics Data System (ADS)

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.

Barnes, Caleb J.; Visbal, Miguel R.

2013-11-01

147

Ultrasonic pipe assessment  

DOEpatents

An ultrasonic pipe or other structure assessment system includes an ultrasonic transducer positioned proximate the pipe or other structure. A fluid connection between the ultrasonic transducer and the pipe or other structure is produced. The ultrasonic transducer is moved relative to the pipe or other structure.

Thomas, Graham H.; Morrow, Valerie L.; Levie, Harold; Kane, Ronald J.; Brown, Albert E.

2003-12-23

148

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

NASA Astrophysics Data System (ADS)

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.

Meng, Xue Guang; Sun, Mao

2013-07-01

149

Flexible ocean upwelling pipe  

SciTech Connect

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.

Person, Abraham (Los Alamitos, CA)

1980-01-01

150

On the isothermal geometry of corrugated graphene sheets  

E-print Network

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.

Andrzej Trzesowski

2014-12-22

151

Using Flexible Pipe (poly-pipe) with Surface Irrigation  

E-print Network

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...

Peries, Xavier; Enciso, Juan

2005-10-05

152

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

153

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

154

Manipulation of Thought Content as a Determinant of Mood and Corrugator Electromyographic Activity in Depressed Patients  

ERIC Educational Resources Information Center

Examines the effects of unhappy thoughts on mood and corrugator EMG (electromyographic activity) in depressed patients. Its purpose was to obtain evidence relevant to cognitive models of depression and to examine the usefulness of corrugator EMG as an indicator of depressed mood. (Author/RK)

Teasdale, John D.; Bancroft, Judy

1977-01-01

155

Heat transfer characteristics of a back-corrugated absorber surface for solar air collectors  

Microsoft Academic Search

Current literature on solar air collectors emphasizes satisfactory heat transfer between the absorber and the flowing air as a major factor in overall performance. Heat transfer in the airflow passages, usually in or near the transitional flow range, is also influenced by entrance effects. The present study experimentally examines a back-corrugated absorber-convector composed of a rectangularly corrugated plate attached to

K. A. Shockey; D. P. DeWitt; J. T. Pearson

1983-01-01

156

Normal fault corrugation: implications for growth and seismicity of active normal faults  

Microsoft Academic Search

Large normal faults are corrugated. Corrugations appear to form from overlapping or en échelon fault arrays by two breakthrough mechanisms: lateral propagation of curved fault-tips and linkage by connecting faults. Both mechanisms include localized fault-parallel extension and eventual abandonment of relay ramps. These breakthrough mechanisms produce distinctive hanging wall and footwall geometries indicative of fault system evolution. From such geometries,

David A Ferrill; John A Stamatakos; Darrell Sims

1999-01-01

157

Emission of surface light waves from a corrugated part of a thin-film waveguide  

Microsoft Academic Search

A theoretical analysis is made of the influence of interference on the emission of surface light waves from a corrugated part of a thin-film waveguide. It is shown that the interference effects are strongest when the film is corrugated on the substrate side. A strong dependence of the attenuation coefficient of a wave on the film thickness and its modulation

A. A. Zlenko; V. A. Kiselev; A. M. Prokhorov; A. A. Spikhal'skii; V. A. Sychugov

1975-01-01

158

Reusable pipe flange covers  

DOEpatents

A molded, flexible pipe flange cover for temporarily covering a pipe flange and a pipe opening includes a substantially round center portion having a peripheral skirt portion depending from the center portion, the center portion adapted to engage a front side of the pipe flange and to seal the pipe opening. The peripheral skirt portion is formed to include a plurality of circumferentially spaced tabs, wherein free ends of the flexible tabs are formed with respective through passages adapted to receive a drawstring for pulling the tabs together on a back side of the pipe flange.

Holden, James Elliott (Simpsonville, SC); Perez, Julieta (Houston, TX)

2001-01-01

159

Role of Bénard-Marangoni instabilities during solvent evaporation in polymer surface corrugations.  

PubMed

Film formation through the drying of polymer solutions is a widely used process in laboratories and in many industrial applications such as coatings. One of the main goals of these applications is to control the film surface morphology. In many cases, evaporation has been found to yield corrugated patterns on the free surface of films. This has been interpreted in terms of either mechanical or hydrodynamic instabilities. In this article, we present experimental results where mesoscale 2D well-ordered surface corrugation patterns are formed during solvent evaporation from polystyrene/toluene solutions. The transformation of Benard-Marangoni instabilities into surface corrugation is studied during the entire drying process using particle tracking, 3D morphology analyses, etc. We show that the corrugation wavelength is controlled by the Benard-Marangoni instability, whereas the corrugation amplitude is controlled by a mechanism that involves a high evaporation rate. PMID:19032111

Bassou, N; Rharbi, Y

2009-01-01

160

Corrugated Waveguide Mode Content Analysis Using Irradiance Moments  

PubMed Central

We present a novel, relatively simple method for determining the mode content of the linearly polarized modes of a corrugated waveguide using the moments of the intensity pattern of the field radiated from the end of the waveguide. This irradiance moment method is based on calculating the low-order irradiance moments, using measured intensity profiles only, of the radiated field from the waveguide aperture. Unlike the phase retrieval method, this method does not use or determine the phase distribution at the waveguide aperture. The new method was benchmarked numerically by comparison with sample mode mixtures. The results predict less than ±0.7% error bar in the retrieval of the mode content. The method was also tested using high-resolution experimental data from beams radiated from 63.5 mm and 19 mm corrugated waveguides at 170 and 250 GHz, respectively. The results showed a very good agreement of the mode content retrieved using the irradiance moment method versus the phase retrieval technique. The irradiance moment method is most suitable for cases where the modal power is primarily in the fundamental HE11 mode, with <8% of the power in high-order modes.

Jawla, Sudheer K.; Shapiro, Michael A.; Idei, Hiroshi; Temkin, Richard J.

2015-01-01

161

Imaging Local Electronic Corrugations and Doped Regions in Graphene  

SciTech Connect

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.

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

2011-12-31

162

Simulation of terahertz generation in corrugated plasma waveguides  

SciTech Connect

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.

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

163

Pipe selection guide  

SciTech Connect

Four parameters are used to define a particular pipe: inside diameter, wall thickness, material, and ends. The factors influencing pipe selection are limited to fluid pressure, temperature, chemistry, flow rate, and cost. Other pipe parameters and factors that influence pipe selection and design are mentioned, and, where appropriate, the user is warned that at some stage in the project these factors must be dealt with. It is assumed that the objective is the direct application of geothermal water at temperatures lower than 200/sup 0/F and with 12-in. or smaller pipe. When considering friction losses for sizing purposes, only straight pipe is considered. A discussion of the characteristics and attributes of readily available pipe is included to aid in making a preliminary selection. Energy loss from buried pipe is considered.

Sanders, R.D.

1982-04-01

164

Heat pipe flight experiments  

NASA Technical Reports Server (NTRS)

OAO 3 heat pipe flight experiments to check out weightlessness behavior are reported. Tested were a hollow channel screen system with helical grooves, a heat pipe with a wicking system of horizontal grooves, and a spiral artery pipe with multichannel fluid return to the evaporator. Flight experiment data proved that all heat pipe geometries containing wicking systems provided uninterrupted fluid return to the condensators during weightlessness and sufficient cooling for isothermalizing optical instruments onboard OAO.

Ollendorf, S.

1973-01-01

165

Pipe-to-pipe impact program  

SciTech Connect

This report documents the tests and analyses performed as part of the Pipe-to-Pipe Impact (PTPI) Program at the Pacific Northwest Laboratory. This work was performed to assist the NRC in making licensing decisions regarding pipe-to-pipe impact events following postulated breaks in high energy fluid system piping. The report scope encompasses work conducted from the program's start through the completion of the initial hot oil tests. The test equipment, procedures, and results are described, as are analytic studies of failure potential and data correlation. Because the PTPI Program is only partially completed, the total significance of the current test results cannot yet be accurately assessed. Therefore, although trends in the data are discussed, final conclusions and recommendations will be possible only after the completion of the program, which is scheduled to end in FY 1984.

Alzheimer, J.M.; Bampton, M.C.C.; Friley, J.R.; Simonen, F.A.

1984-06-01

166

Antigravity heat pipe  

Microsoft Academic Search

The general design and principle of operation of an antigravity heat pipe, in which the heat transfer agent is supplied to the evaporator against the force of gravity, are descussed. Analytical expressions describing the operation of the heat pipe are presented, as are experimental results obtained for an acetone-charged antigravity heat pipe.

N. I. Kliuev

1989-01-01

167

Diffusion of pipe jets  

Microsoft Academic Search

This paper presents fundamental research work on jet dissipation in pipes and closed chambers in order to study the details of flow pattern, velocity distribution, and energy reduction. The effects of chamber dimensions and jet heights are also investigated. Experiments were carried out with air and water jets being discharged into a pipe. The ratio of pipe to nozzle diameter

S. K. Al-Naib; R. Vasanthakumaran

1993-01-01

168

Overall Thermal Performance of Flexible Piping Under Simulated Bending Conditions  

NASA Technical Reports Server (NTRS)

Flexible, vacuum-insulated transfer lines for low-temperature applications have higher thermal losses than comparable rigid lines. Typical flexible piping construction uses corrugated tubes, inner and outer, with a multilayer insulation (MLI) system in the annular space. Experiments on vacuum insulation systems in a flexible geometry were conducted at the Cryogenics Test Laboratory of NASA Kennedy Space Center. The effects of bending were simulated by causing the inner tube to be eccentric with the outer tube. The effects of spacers were simulated in a controlled way by inserting spacer tubes for the length of the cylindrical test articles. Two material systems, standard MLI and a layered composite insulation (LCI), were tested under the full range of vacuum levels using a liquid nitrogen boiloff calorimeter to determine the apparent thermal conductivity (k-value). The results indicate that the flexible piping under simulated bending conditions significantly degrades the thermal performance of the insulation system. These data are compared to standard MLI for both straight and flexible piping configurations. The definition of an overall k-value for actual field installations (k(sub oafi)) is described for use in design and analysis of cryogenic piping systems.

Fesmire, James E.; Augustynowicz, S. D.; Demko, J. A.; Thompson, Karen (Technical Monitor)

2001-01-01

169

Amygdala Volume Predicts Prolonged Response to Negative Stimuli, Whereas Hippocampal Volume Predicts Prolonged Response to Positive Stimuli (As Indexed by Corrugator Facial EMG)  

E-print Network

Predicts Prolonged Response to Positive Stimuli (As Indexed by Corrugator Facial EMG) Stacey M. Schaefer1 manually traced on each participant's structural MRI. Corrugator EMG was used as a metric of emotional) corrugator EMG across trial type, showing expected increased corrugator EMG for negative picture trials

170

Pipe Line Control  

NASA Technical Reports Server (NTRS)

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.

1978-01-01

171

Numerical investigation of the aerodynamic and structural characteristics of a corrugated wing  

NASA Astrophysics Data System (ADS)

Previous experimental studies on static, bio-inspired corrugated wings have shown that they produce favorable aerodynamic properties such as delayed stall compared to streamlined wings and flat plates at high Reynolds numbers (Re ? 4x104). The majority of studies have been carried out with scaled models of dragonfly forewings from the Aeshna Cyanea in either wind tunnels or water channels. In this thesis, the aerodynamics of a corrugated airfoil was studied using computational fluid dynamics methods at a low Reynolds number of 1000. Structural analysis was also performed using the commercial software SolidWorks 2009. The flow field is described by solving the incompressible Navier-Stokes equations on an overlapping grid using the pressure-Poisson method. The equations are discretized in space with second-order accurate central differences. Time integration is achieved through the second-order Crank-Nicolson implicit method. The complex vortex structures that form in the corrugated airfoil valleys and around the corrugated airfoil are studied in detail. Comparisons are made with experimental measurements from corrugated wings and also with simulations of a flat plate. Contrary to the studies at high Reynolds numbers, our study shows that at low Reynolds numbers the wing corrugation does not provide any aerodynamic benefit compared to a smoothed flat plate. Instead, the corrugated profile generates more pressure drag which is only partially offset by the reduction of friction drag, leading to more total drag than the flat plate. Structural analysis shows that the wing corrugation can increase the resistance to bending moments on the wing structure. A smoothed structure has to be three times thicker to provide the same stiffness. It was concluded the corrugated wing has the structural benefit to provide the same resistance to bending moments with a much reduced weight.

Hord, Kyle

172

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

NASA Astrophysics Data System (ADS)

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.

Hou, Shenyong; Yu, Sheng; Li, Hongfu

2015-03-01

173

Experimental and analytical determination of vibration characteristics of corrugated, flexibly supported, heat-shield panels  

NASA Technical Reports Server (NTRS)

Experimental and analytical natural frequencies, nodal patterns, and typical modal displacements for a corrugated, flexibly supported, heat-shield panel are discussed. Good correlation was found between the experimental data and NASTRAN analytical results for the corrugated panel over a relatively wide frequency spectrum covered in the investigation. Of the two experimental techniques used for mode shape and displacement measurements (a noncontacting displacement sensor system and a holographic technique using a helium-neon, continuous-wave laser), the holographic technique was found, in the present investigation, to be faster and better suited for determining a large number of complex nodal patterns of the corrugated panel.

Carden, H. D.

1974-01-01

174

Gyrokinetic simulations of off-axis minimum-q profile corrugations  

SciTech Connect

Quasiequilibrium radial 'profile corrugations' in the electron temperature gradient are found at lowest-order singular surfaces in global gyrokinetic code simulations of both monotonic-q and off-axis minimum-q discharges. The profile corrugations in the temperature and density gradients are time-averaged components of zonal flows. The m/n=2/1 electron temperature gradient corrugation is measurably large and appears to trigger an internal transport barrier as the off-axis minimum-q=2 surfaces enter the plasma.

Waltz, R.E.; Austin, M.E.; Burrell, K.H.; Candy, J. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States)

2006-05-15

175

Non-Classical Smoothening of Nano-Scale Surface Corrugations  

SciTech Connect

We report the first experimental observation of non-classical morphological equilibration of a corrugated crystalline surface. Periodic rippled structures with wavelengths of 290-550 nm were made on Si(OO1) by sputter rippling and then annealed at 650 - 750 °C. In contrast to the classical exponential decay with time, the ripple amplitude, A{lambda}(t), followed an inverse linear decay, A{lambda}(t)= A{lambda}(0)/(1 +k{lambda}t), agreeing with a prediction of Ozdemir and Zangwill. We measure the activation energy for surface relaxation to be 1.6±0.2 eV, consistent with an interpretation that dimers mediate transport.

Aziz, Michael J.; Chason, Eric; Erlebacher, Jonah; Floro, Jerrold A.; Sinclair, Michael B.

1999-05-20

176

Unexpected crossover dynamics of single polymer in a corrugated tube  

NASA Astrophysics Data System (ADS)

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 ? < 2.3, the axial diffusion coefficient D|| scales as D|| ? N-3/2, with chain length N, up to N ? 100 and then crosses over to Rouse scaling for the larger N values. The N-3/2 scaling is due to the large fluctuation of the polymer chain along its fully stretched equilibrium conformation. The stronger scaling, namely N-3/2, is not observed for an atomistically smooth tube and/or for a cylinder with larger diameter.

De Virgiliis, Andres; Kuban, Lukasz; Paturej, Jaroslaw; Mukherji, Debashish

2012-09-01

177

Atomistic origin of radial corrugation in a few-walled carbon nanotubes: A molecular dynamics study  

NASA Astrophysics Data System (ADS)

We perform molecular dynamics simulations of a few-walled (with 3-4 walls) carbon nanotubes using empirical interatomic potential. We demonstrate that the radial corrugation occurs in such thin nanotubes under hydrostatic pressure, which is apparently similar to the corrugation in thicker (e.g., several tens-walled) nanotubes that had been predicted using continuum mechanics approximation. The mechanism underlying the corrugation of a few-walled nanotubes, however, is found to be much distinct from thick nanotubes; i.e., the sp3 bonds between adjacent concentric walls and registry of atom arrangement take important roles in the formation and stabilization of corrugation modes in a few-walled nanotubes.

Umeno, Yoshitaka; Koike, Ikuyo; Kusano, Ayako; Shima, Hiroyuki; Sato, Motohiro

2015-01-01

178

Trapping surface plasmon polaritons on ultrathin corrugated metallic strips in microwave frequencies.  

PubMed

It has been demonstrated that an ultrathin uniformly corrugated metallic strip is a good plasmonic waveguide in microwave and terahertz frequencies to propagate spoof surface plasmon polaritons (SPPs) with well confinement and small loss (Shen et al., PNAS 110, 40-45, 2013). Here, we propose a simple method to trap SPP waves on the ultrathin corrugated metallic strips in broad band in the microwave frequencies. By properly designing non-uniform corrugations with gradient-depth grooves, we show that the SPP waves are slowed down gradually and then reflected at pre-designed positions along the ultrathin metallic strip when the frequency varies. We design and fabricate the ultrathin gradient-corrugation metallic strip on a thin dielectric film. Both numerical simulation and measurement results validate the efficient trapping of SPP waves in broadband from 9 to 14 GHz. This proposal is a promising candidate for slow-wave devices in both microwave and terahertz regimes. PMID:25837047

Yang, Yan; Shen, Xiaopeng; Zhao, Pei; Zhang, Hao Chi; Cui, Tie Jun

2015-03-23

179

Heat transfer and fluid flow characteristics of spanwise-periodic corrugated ducts  

NASA Astrophysics Data System (ADS)

An analytical study is made of the laminar flow and heat transfer in ducts whose cross section is bounded by a wall with periodic corrugations distributed across the span; the other bounding wall is parallel to the corrugated wall and is plane. The study consists of two parts, the first of which is aimed at providing basic heat transfer and fluid flow results while the second utilizes and illuminates these results by means of performance evaluation and comparisons. The basic results, determined numerically, encompass Nusselt numbers, friction factors, isovels and isotherms, and cross sectional mass flow distributions. For the performance evaluations, comparisons were made between the corrugated-wall duct and the parallel plate channel. It was demonstrated that if the temperature of the duct wall is to be minimized, as in an air-operated solar collector, a corrugated duct can be highly effective, but at the price of additional surface area and greater duct height.

Sparrow, E. M.; Charmchi, M.

1980-04-01

180

Piping inspection instrument carriage  

SciTech Connect

This invention is comprised of a pipe inspection instrument carriage for use with a pipe crawler or other locomotion means 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 means mounted distally thereon for axially aligning the inspection instrumentation and means for extending the inspection instruments radially outward to operably position the inspection instruments on the piping interior. Also, the carriage has means 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.

Zollinger, W.T.; Treanor, R.C.

1993-09-20

181

Deployable Heat Pipe Radiator  

NASA Technical Reports Server (NTRS)

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.

Edelstein, F.

1975-01-01

182

Polyvinylchloride (PVC) pipe hazards  

SciTech Connect

PVC pipe should be used only for low pressure liquid systems where the liquid is at or near ambient temperature. PVC pipe, because of its brittle nature, should be used only in unmanned areas or where it is isolated from personnel. It should be otherwise protected so that it is not subjected to ultraviolet light, temperature cycling or damage after installation. Heat (particularly welding and cutting) should be avoided in the immediate vicinity of the piping. PVC pipe should not be used where it would be subject to vibration. The effects of certain chemicals on PVC should be carefully considered, both where the pipe is a carrying medium for the chemical and where the pipe may be exposed to the chemicals externally.

Not Available

1983-01-01

183

Simulation of accordion effect in corrugated steel web with concrete flanges  

Microsoft Academic Search

Prestressed concrete girders with corrugated steel webs are one of the promising concrete–steel hybrid structures applied to highway bridges. Prestress can be efficiently introduced into the concrete flanges due to the so-called “accordion effect” of the corrugated web. In this paper, a simple approach is presented to account for three-dimensional phenomena of the accordion effect using link-type elements within a

Ling Huang; Hiroshi Hikosaka; Keizo Komine

2004-01-01

184

Numerical and Experimental Investigations on Mechanical Behavior of Composite Corrugated Core  

NASA Astrophysics Data System (ADS)

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.

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

2012-06-01

185

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

Microsoft Academic Search

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

Feixiang Ke; Jianmin Miao; Joachim Oberhammer

2008-01-01

186

Abrasion resistant heat pipe  

DOEpatents

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.

Ernst, Donald M. (Leola, PA)

1984-10-23

187

Pipe crawler apparatus  

DOEpatents

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.

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

2002-01-01

188

External artery heat pipe  

NASA Technical Reports Server (NTRS)

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.

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

1989-01-01

189

Heat Pipe Materials Compatibility  

NASA Technical Reports Server (NTRS)

An experimental program to evaluate noncondensable gas generation in ammonia heat pipes was completed. A total of 37 heat pipes made of aluminum, stainless steel and combinations of these materials were processed by various techniques, operated at different temperatures and tested at low temperature to quantitatively determine gas generation rates. In order of increasing stability are aluminum/stainless combination, all aluminum and all stainless heat pipes. One interesting result is the identification of intentionally introduced water in the ammonia during a reflux step as a means of surface passivation to reduce gas generation in stainless-steel/aluminum heat pipes.

Eninger, J. E.; Fleischman, G. L.; Luedke, E. E.

1976-01-01

190

Internal pipe attachment mechanism  

DOEpatents

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.

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

1994-12-13

191

Heat pipe investigations  

NASA Technical Reports Server (NTRS)

The OAO-C spacecraft has three circular heat pipes, each of a different internal design, located in the space between the spacecraft structural tube and the experiment tube, which are designed to isothermalize the structure. Two of the pipes are used to transport high heat loads, and the third is for low heat loads. The test problems deal with the charging of the pipes, modifications, the mobile tilt table, the position indicator, and the heat input mechanisms. The final results showed that the techniques used were adequate for thermal-vacuum testing of heat pipes.

Marshburn, J. P.

1972-01-01

192

Internal pipe attachment mechanism  

DOEpatents

An attachment mechanism 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.

Bast, Richard M. (Livermore, CA); Chesnut, Dwayne A. (Pleasanton, CA); Henning, Carl D. (Livermore, CA); Lennon, Joseph P. (Livermore, CA); Pastrnak, John W. (Livermore, CA); Smith, Joseph A. (Livermore, CA)

1994-01-01

193

Heat pipe technology issues  

SciTech Connect

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.

Merrigan, M.A.

1984-04-01

194

Loop heat pipes  

Microsoft Academic Search

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

Yu. F. Maydanik

2005-01-01

195

The heat pipe  

Microsoft Academic Search

The heat pipe is a device having a high thermal conductance which utilizes the transport of a vapour and rejection of latent heat to achieve efficient thermal energy transport. The theory of heat pipes is well developed. Their use in applications involving temperatures in the cryogenic regime, and with development units running as high as 2000 degrees C, shows that

P. D. Dunn; D. A. Reay

1973-01-01

196

Modulated wick heat pipe  

Microsoft Academic Search

In heat pipes, modulation of evaporator wick thickness provides extra cross-sectional area for enhanced axial capillary liquid flow and extra evaporation surface area, with only a moderate increase in wick superheat (conduction resistance). This modulated wick (periodic stacks and grooves over a thin, uniform wick) is analyzed and optimized with a prescribed, empirical wick superheat limit. A thermal-hydraulic heat pipe

G. S. Hwang; M. Kaviany; W. G. Anderson; J. Zuo

2007-01-01

197

Corrugator activity confirms immediate negative affect in surprise  

PubMed Central

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

Topolinski, Sascha; Strack, Fritz

2015-01-01

198

Corrugated Quantum Well Infrared Photodetector Focal Plane Array Test Results  

NASA Technical Reports Server (NTRS)

The corrugated quantum-well infrared photodetector (C-QWIP) uses total internal reflection to couple normal incident light into the optically active quantum wells. The coupling efficiency has been shown to be relatively independent of the pixel size and wavelength thus making the C-QWIP a candidate for detectors over the entire infrared spectrum. The broadband coupling efficiency of the C-QWIP makes it an ideal candidate for multiwavelength detectors. We fabricated and tested C-QWIP focal plane arrays (FPAs) with cutoff wavelengths of 11.2 and 16.2 micrometers. Each FPA has 256 x 256 pixels that are bump-bonded to a direct injection readout circuit. Both FPAs provided infrared imagery with good aesthetic attributes. For the 11.2-micrometers FPA, background-limited performance (BLIP) was observed at 60 K with f/3 optics. For the 16.2-micrometers FPA, BLIP was observed at 38 K. Besides the reduction of dark current in C-QWIP structures, the measured internal quantum efficiency (eta) remains to be high. The values for responsivity and quantum efficiency obtained from the FPA results agree well with those measured for single devices.

Goldberg, A.; Choi, K. K.; Das, N. C.; La, A.; Jhabvala, M.

1999-01-01

199

Extendable pipe crawler  

DOEpatents

A pipe crawler having a front leg assembly and a back leg assembly connected together by two air cylinders, each leg assembly having four extendable legs and a pair of actuators for sliding the extendable legs radially outward to increase the range of the legs when the pipe crawler enters a section of a pipe having a larger diameter. The crawler crawls by "inchworm"-like motion, the front leg assembly and back leg assembly alternately engaging and disengaging the wall of the pipe to hold the pipe crawler as the air cylinders alternately advance the front leg assembly and bring up the rear leg assembly. The pair of actuators of each leg assembly are parallel, adjacent and opposing acting so that each slides two adjacent extendable legs radially outward.

Hapstack, Mark (North Augusta, SC)

1991-01-01

200

Extendable pipe crawler  

DOEpatents

A pipe crawler is described having a front leg assembly and a back leg assembly connected together by two air cylinders, each leg assembly having four extendable legs and a pair of actuators for sliding the extendable legs radially outward to increase the range of the legs when the pipe crawler enters a section of a pipe having a larger diameter. The crawler crawls by inchworm'-like motion, the front leg assembly and back leg assembly alternately engaging and disengaging the wall of the pipe to hold the pipe crawler as the air cylinders alternately advance the front leg assembly and bring up the rear leg assembly. The pair of actuators of each leg assembly are parallel, adjacent and opposing acting so that each slides two adjacent extendable legs radially outward. 5 figures.

Hapstack, M.

1991-05-28

201

Coherent mode coupling in highly efficient top-emitting OLEDs on periodically corrugated substrates.  

PubMed

Bragg scattering at one-dimensional corrugated substrates allows to improve the light outcoupling from top-emitting organic light-emitting diodes (OLEDs). The OLEDs rely on a highly efficient phosphorescent pin stack and contain metal electrodes that introduce pronounced microcavity effects. A corrugated photoresist layer underneath the bottom electrode introduces light scattering. Compared to optically optimized reference OLEDs without the corrugated substrate, the corrugation increases light outcoupling efficiency but does not adversely affect the electrical properties of the devices. The external quantum efficiency (EQE) is increased from 15 % for an optimized planar layer structure to 17.5 % for a corrugated OLED with a grating period of 1.0 ?m and a modulation depth of about 70 nm. Detailed analysis and optical modeling of the angular resolved emission spectra of the OLEDs provide evidence for Bragg scattering of waveguided and surface plasmon modes that are normally confined within the OLED stack into the air-cone. We observe constructive and destructive interference between these scattered modes and the radiative cavity mode. This interference is quantitatively described by a complex summation of Lorentz-like resonances. PMID:24718126

Schwab, Tobias; Fuchs, Cornelius; Scholz, Reinhard; Zakhidov, Alexander; Leo, Karl; Gather, Malte C

2014-04-01

202

An experimental study of a bio-inspired corrugated airfoil for micro air vehicle applications  

NASA Astrophysics Data System (ADS)

An experimental study was conducted to investigate the aerodynamic characteristics of a bio-inspired corrugated airfoil compared with a smooth-surfaced airfoil and a flat plate at the chord Reynolds number of Re C = 58,000-125,000 to explore the potential applications of such bio-inspired corrugated airfoils for micro air vehicle designs. In addition to measuring the aerodynamic lift and drag forces acting on the tested airfoils, a digital particle image velocimetry system was used to conduct detailed flowfield measurements to quantify the transient behavior of vortex and turbulent flow structures around the airfoils. The measurement result revealed clearly that the corrugated airfoil has better performance over the smooth-surfaced airfoil and the flat plate in providing higher lift and preventing large-scale flow separation and airfoil stall at low Reynolds numbers (Re C < 100,000). While aerodynamic performance of the smooth-surfaced airfoil and the flat plate would vary considerably with the changing of the chord Reynolds numbers, the aerodynamic performance of the corrugated airfoil was found to be almost insensitive to the Reynolds numbers. The detailed flow field measurements were correlated with the aerodynamic force measurement data to elucidate underlying physics to improve our understanding about how and why the corrugation feature found in dragonfly wings holds aerodynamic advantages for low Reynolds number flight applications.

Murphy, Jeffery T.; Hu, Hui

2010-08-01

203

Experimenting with a "Pipe" Whistle  

ERIC Educational Resources Information Center

A simple pipe whistle can be made using pieces of PVC pipe. The whistle can be used to measure the resonant frequencies of open or closed pipes. A slightly modified version of the device can be used to also investigate the interesting dependence of the sound frequencies produced on the orifice-to-edge distance. The pipe whistle described here…

Stafford, Olga

2012-01-01

204

Introduction to pipe stress analysis  

Microsoft Academic Search

This book offers a practical approach to analytical piping design. Many approaches to design are presented that are used in engineering consulting companies but are not available in books. Engineering equations from many piping codes are used and discussed. Covers problems encountered in the determination of pipe wall thickness and span limitations, design of piping configurations and supports and connections

Kannappan

1986-01-01

205

Flexible ultrasonic pipe inspection apparatus  

DOEpatents

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.

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

1994-01-01

206

Gas pipe explorer robot  

NASA Technical Reports Server (NTRS)

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.

Wilcox, Brian (Inventor)

2004-01-01

207

Friction loss in piping  

SciTech Connect

This program for the HP-41C with one memory module computes pipe friction loss, velocity, and optimum diameter given pipe ID, flow rate, viscosity and density. Flow can be entered as 1.lb/h, 2.BPH-/sup 0/API, 3. gas mol. wt.-scfh, or 4. gpm-sp.gr. Density can be entered as 1.lb/ft, 2. mol. wt.-psig-/sup 0/F, or 3. /sup 0/API-/sup 0/F. For some standard strength pipes, nominal to actual diameter conversion is provided. A change in gas density with pressure can be taken into account if desired.

Patel, V.K.

1984-01-01

208

Optomechanic interaction in a corrugated phoxonic nanobeam cavity  

NASA Astrophysics Data System (ADS)

The interaction between phonons and photons is investigated theoretically in a phoxonic cavity inside a corrugated nanobeam waveguide presenting band gaps for both electromagnetic and elastic waves. The structure is made by drilling periodic holes on a silicon nanobeam with lateral periodic stubs and the tapered cavity is constructed by changing gradually the geometrical parameters of both the holes and stubs. We show that this kind of cavity displays localized phonons and photons inside the gaps, which can enhance their interaction and also promotes the presence of many optical confined modes with high quality factor. Using the finite-element method, we demonstrate that with appropriate design of the tapering construction, one can control the cavity modes frequency without altering significantly the quality factor of the photonic modes. By changing the tapering rates over the lattice constants, we establish the possibility of shifting the phononic cavity modes frequency to place them inside the desired gap, which enhances their confinement and increases the mechanical quality factor while keeping the strength of the optomechanic coupling high. In our calculations, we take account of both mechanisms that contribute to the acousto-optic interaction, namely photoelastic and interface motion effects. We show that in our case, these two effects can contribute additively to give high coupling strength between phononic and photonic cavity modes. The calculations of the coupling coefficient which gives the phonon-photon coupling strength give values as high as 2 MHz while photonic cavity modes display quality factor of 105 and even values up to 3.4 MHz but with smaller photonic quality factors.

Oudich, Mourad; El-Jallal, Said; Pennec, Yan; Djafari-Rouhani, Bahram; Gomis-Bresco, Jordi; Navarro-Urrios, Daniel; Sotomayor Torres, Clivia M.; Martínez, Alejandro; Makhoute, Abdelkader

2014-06-01

209

Heat Pipe Systems  

NASA Technical Reports Server (NTRS)

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.

1993-01-01

210

Heat pipe manufacturing study  

NASA Technical Reports Server (NTRS)

Heat pipe manufacturing methods are examined with the goal of establishing cost effective procedures that will ultimately result in cheaper more reliable heat pipes. Those methods which are commonly used by all heat pipe manufacturers have been considered, including: (1) envelope and wick cleaning, (2) end closure and welding, (3) mechanical verification, (4) evacuation and charging, (5) working fluid purity, and (6) charge tube pinch off. The study is limited to moderate temperature aluminum and stainless steel heat pipes with ammonia, Freon-21 and methanol working fluids. Review and evaluation of available manufacturers techniques and procedures together with the results of specific manufacturing oriented tests have yielded a set of recommended cost-effective specifications which can be used by all manufacturers.

Edelstein, F.

1974-01-01

211

Heat pipe development  

NASA Technical Reports Server (NTRS)

The objective of this program was to investigate analytically and experimentally the performance of heat pipes with composite wicks--specifically, those having pedestal arteries and screwthread circumferential grooves. An analytical model was developed to describe the effects of screwthreads and screen secondary wicks on the transport capability of the artery. The model describes the hydrodynamics of the circumferential flow in triangular grooves with azimuthally varying capillary menisci and liquid cross-sections. Normalized results were obtained which give the influence of evaporator heat flux on the axial heat transport capability of the arterial wick. In order to evaluate the priming behavior of composite wicks under actual load conditions, an 'inverted' glass heat pipe was designed and constructed. The results obtained from the analysis and from the tests with the glass heat pipe were applied to the OAO-C Level 5 heat pipe, and an improved correlation between predicted and measured evaporator and transport performance were obtained.

Bienart, W. B.

1973-01-01

212

DRAINAGE PIPE DETECTOR  

Technology Transfer Automated Retrieval System (TEKTRAN)

One of the more frustrating problems confronting farmers and land improvement contractors in the Midwestern United States involves locating buried agricultural drainage pipes. Conventional geophysical methods, particularly ground penetrating radar (GPR), presently being used for environmental and co...

213

Quantitative allocation of Bragg scattering effects in highly efficient OLEDs fabricated on periodically corrugated substrates.  

PubMed

Bragg scattering effects in bottom-emitting organic light-emitting diodes (OLEDs) grown on corrugated aluminum-doped zinc oxide electrodes are analyzed. Periodic corrugation is introduced by structuring the oxide electrode via UV laser ablation, a process that enables flexible adjustment of the period and height of corrugation. We demonstrate that fabrication of stable and electrically efficient OLEDs on these rough substrates is feasible. Sharp spectral features are superimposed onto the broad emission spectra of the OLEDs, providing clear evidence for Bragg scattering of light from guided modes into the air cone. Theoretical analysis based on an emissive dipole model and conservation of momentum considerations allows a quantitative description of scattering and the associated dispersion relations. PMID:23938484

Fuchs, C; Schwab, T; Roch, T; Eckardt, S; Lasagni, A; Hofmann, S; Lüssem, B; Müller-Meskamp, L; Leo, K; Gather, M C; Scholz, R

2013-07-15

214

Reduction of out-of-plane warpage in surface micromachined beams using corrugation  

NASA Astrophysics Data System (ADS)

Corrugation is proposed as a means of reducing the out-of-plane warpage in surface micromachined beams that result from an asymmetric vertical stress profile. Corrugation increases beam bending stiffness without increasing film thickness, making the beam more immune to intrinsic vertical stress gradients without requiring longer film deposition times, increased beam mass, or careful stress optimization. The technique was tested using a dual-thickness metal surface micromachining process with a photoresist sacrificial layer. Several corrugation patterns and geometries were tested, and the best performing pattern was implemented on a MEMS actuator array. The off-state to on-state capacitance delta of the array improved from 0.24 to 0.7pF and the beam curvature decreased from 180 to 50 nm compared with an uncorrugated array. Other device performance parameters, such as 30 V pull-in voltage and 5 billion cycle switching lifetime, were unaffected.

Gupta, Arun; Barron, Lance; Brainin, Michael; Lee, Jeong-Bong

2014-06-01

215

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

NASA Astrophysics Data System (ADS)

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.

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

216

Impact-damaged graphite-thermoplastic trapezoidal-corrugation sandwich and semi-sandwich panels  

NASA Technical Reports Server (NTRS)

The results of a study of the effects of impact damage on compression-loaded trapezoidal-corrugation sandwich and semi-sandwich graphite-thermoplastic panels are presented. 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 in this study. Panels were designed, fabricated and tested. The panels were made using the manufacturing process of thermoforming, a less-commonly used technique for fabricating composite parts. Experimental results for unimpacted control panels and panels subjected to impact damage prior to loading are presented. Little work can be found in the literature about these configurations of thermoformed panels.

Jegley, D.

1993-01-01

217

Trapping of surface plasmon wave through gradient corrugated strip with underlayer ground and manipulating its propagation  

NASA Astrophysics Data System (ADS)

Corrugated metal surface with underlayer metal as ground is designed as spoof surface plasmons polaritons (SSPPs) structure in microwave frequencies. Efficient conversion from guided wave to SSPP is required for energy feeding into and signal extracting from such plasmonic structure. In this paper, first a high efficient transition design is presented by using gradient corrugated strip with underlayer metal as ground and by using the impedance matching theory. The SSPP wave is highly confined within the teeth part of the corrugated surface. By using this characteristic, then the simple wire-based metamaterial is added below the strip to manipulate the SSPP wave within the propagating band. Two aforementioned devices are designed and fabricated. The simulated and measured results on the scattering coefficients demonstrate the excellent conversion and excellent manipulating of SSPP transmitting. Such results have very important value to develop advanced plasmonic integrated circuits in the microwave frequencies.

Zhang, Wenjuan; Zhu, Guiqiang; Sun, Liguo; Lin, Fujiang

2015-01-01

218

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

E-print Network

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.

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

219

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

PubMed

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

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

220

Effects of corrugation angle on developing laminar forced convection and entropy generation in a wavy channel  

NASA Astrophysics Data System (ADS)

This paper investigates the effects of corrugation angle ( ?) on the developing laminar forced convection and entropy generation in a wavy channel with numerical methods. The studied cases cover ? = 10-, 15-, 20-, 25-, 30- and 35°, whilst Reynolds number ( Re) is varied as 100, 200 and 400. The analyzed flow characteristics include recirculating flows, secondary vortices, temperature distributions, and friction factor as well as Nusselt number. In particular, the effects of corrugation angle on the distributions and magnitudes of local entropy generation resulted from frictional irreversibility ( S {/P '''}) and heat transfer irreversibility ( S {/T '''}) are separately discussed in detail in the present paper. Based on the minimal entropy generation principle, the optimal corrugation angle and favorable Re are reported.

Ko, Tzu-Hsiang

2007-12-01

221

Electromagnetohydrodynamic (EMHD) micropump of Jeffrey fluids through two parallel microchannels with corrugated walls  

NASA Astrophysics Data System (ADS)

By employing the perturbation method, the approximate analytical solutions of velocity and volume flow rate are presented for electromagnetohydrodynamic (EMHD) flow of an electrically conducting, incompressible and viscous Jeffrey fluid between two slit microparallel plates with corrugated walls. The corrugations of the two walls are described as periodic sinusoidal waves with small amplitude either in phase or half-period out of phase. The effects of the corrugations on the EMHD flow velocity are analyzed by using numerical computation. The variations of velocity profiles and mean velocity parameter and their dependences on the Reynolds number Re, Hartmann number Ha, dimensionless wave number ? of the wall perturbation, the dimensionless relaxation time ?1? and retardation time ?2? are explained graphically.

Si, Dongqing; Jian, Yongjun

2015-03-01

222

Simplified pipe gun  

NASA Astrophysics Data System (ADS)

A simplified version of a deuterium pellet gun based on the pipe gun principle is described. The pipe gun is made from a continuous tube of stainless steel and gas is fed in from the muzzle end only. It is indicated that the pellet length is determined by the temperature gradient along the barrel right outside the freezing cell. Velocities of around 1000 m/s with a scatter of ±2% are obtained with a propellant gas pressure of 40 bar.

Sørensen, H.; Nordskov, A.; Sass, B.; Visler, T.

1987-12-01

223

Silicon Heat Pipe Array  

NASA Technical Reports Server (NTRS)

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.

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

2013-01-01

224

Freezable heat pipe  

DOEpatents

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.

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

1981-02-03

225

Determination of the geometric corrugation of graphene on SiC(0001) by grazing incidence fast atom diffraction  

NASA Astrophysics Data System (ADS)

We present a grazing incidence fast atom diffraction (GIFAD) study of monolayer graphene on 6H-SiC(0001). This system shows a Moiré-like 13 × 13 superlattice above the reconstructed carbon buffer layer. The averaging property of GIFAD results in electronic and geometric corrugations that are well decoupled; the graphene honeycomb corrugation is only observed with the incident beam parallel to the zigzag direction while the geometric corrugation arising from the superlattice is revealed along the armchair direction. Full-quantum calculations of the diffraction patterns show the very high GIFAD sensitivity to the amplitude of the surface corrugation. The best agreement between the calculated and measured diffraction intensities yields a corrugation height of 0.27 ± 0.03 Å.

Zugarramurdi, A.; Debiossac, M.; Lunca-Popa, P.; Mayne, A. J.; Momeni, A.; Borisov, A. G.; Mu, Z.; Roncin, P.; Khemliche, H.

2015-03-01

226

An experimental study of a bio-inspired corrugated airfoil for micro air vehicle applications  

Microsoft Academic Search

An experimental study was conducted to investigate the aerodynamic characteristics of a bio-inspired corrugated airfoil compared\\u000a with a smooth-surfaced airfoil and a flat plate at the chord Reynolds number of Re\\u000a C\\u000a  = 58,000–125,000 to explore the potential applications of such bio-inspired corrugated airfoils for micro air vehicle designs.\\u000a In addition to measuring the aerodynamic lift and drag forces acting on

Jeffery T. Murphy; Hui Hu

2010-01-01

227

Graphene-assisted near-field radiative heat transfer between corrugated polar materials  

SciTech Connect

Graphene has attracted great attention in nanoelectronics, optics, and energy harvesting. Here, the near-field radiative heat transfer between graphene-covered corrugated silica is investigated based on the exact scattering theory. It is found that graphene can improve the radiative heat flux between silica gratings by more than one order of magnitude and alleviate the performance sensitivity to lateral shift. The underlying mechanism is mainly attributed to the improved photon tunneling of modes away from phonon resonances. Besides, coating with graphene leads to nonlocal radiative transfer that breaks Derjaguin's proximity approximation and enables corrugated silica to outperform bulk silica in near-field radiation.

Liu, X. L.; Zhang, Z. M., E-mail: zhuomin.zhang@me.gatech.edu [G. W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)

2014-06-23

228

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

NASA Technical Reports Server (NTRS)

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.

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

1984-01-01

229

Corrugated Silicon Platelet Feed Horn Array for CMB Polarimetry at 150 GHz  

E-print Network

Next generation cosmic microwave background (CMB) polarization anisotropy measurements will feature focal plane arrays with more than 600 millimeter-wave detectors. We make use of high-resolution photolithography and wafer-scale etch tools to build planar arrays of corrugated platelet feeds in silicon with highly symmetric beams, low cross-polarization and low side lobes. A compact Au-plated corrugated Si feed designed for 150 GHz operation exhibited performance equivalent to that of electroformed feeds: ~-0.2 dB insertion loss, platelets as a prototype for the SPTpol and ACTpol telescopes. Our fabrication facilities permit arrays up to 150 mm in diameter.

Britton, Joseph W; Yoon, Ki Won; Beall, James A; Becker, Dan; Cho, Hsiao-Mei; Hilton, Gene C; Hubmayr, Johannes; Niemack, Michael D; Irwin, Kent D

2010-01-01

230

Buckling and vibration of circumferentially corrugated cylinders under uniform external water pressure  

SciTech Connect

The paper describes a theoretical and an experimental investigation into the buckling and vibration of two circumferentially corrugated steel cylinders under external water pressure. The buckling tests showed that the vessels were very sensitive to the magnitudes of their initial out-of-circularity and their slenderness. The tests also showed that circumferentially corrugated circular cylinders may prove a suitable alternative to ring-stiffened vessels. The vibration tests showed that the magnitudes of the resonant frequencies of the vessels decreased considerably when the vessels were put into water, and these frequencies decreased even further when the vessels were subjected to external water pressure.

Ross, C.T.F.; Lilleland, S.E.; Richards, W.D.; Little, A.P.F. [Univ. of Portsmouth (United Kingdom). Dept. of Mechanical and Manufacturing Engineering

1996-11-01

231

An experimental investigation of beam shear webs utilizing corrugations for stiffeners  

E-print Network

of the Requirements for the Degree of MASTER OF SCIENCE August, 1959 Department of Aeronautical Engineering Major Subject: Aeronautical Engineering AN EXPERIMENTAL INVESTIGATION OF BEAM SHEAR WEBS UTILIZING CORRUGATIONS FOR STIFFENERS A Thesis JOSEPH HEBERT...-Deflection Diagram for Beams 1, 2, and 3 at x ~ 1/2 incho o ~ i ~ . a o o o o . o a o s 59 49. Load-Deflection Diagram for Beams 1, 2, and 3 at x ~ 17 rnches . . . . . . . . . ~ ~ ~ . ~ ~ 60 50. Crippling of 2024-T3 Alclad Webs Utilizing Corrugation...

Hebert, Joseph

1959-01-01

232

The symmetry plane boundary layer on a corrugated cylinder in cross flow  

NASA Astrophysics Data System (ADS)

The paper discusses the leading edge symmetry plane boundary layer (the attachment line) on a longitudinally corrugated circular cylinder in cross flow. This configuration contains pairs of nodal and saddle points of attachment. There is one component of flow along the attachment line from the nodal towards the saddle point. It is shown that for deep enough corrugations the boundary layer on the attachment line experiences a local separation before reaching the saddle point. However, this separation is weak and does not disturb the flow at the saddle point, which remains locally determined.

von Kerczek, C. H.

233

Heat Pipe Integrated Microsystems  

SciTech Connect

The trend in commercial electronics packaging to deliver ever smaller component packaging has enabled the development of new highly integrated modules meeting the demands of the next generation nano satellites. At under ten kilograms, these nano satellites will require both a greater density electronics and a melding of satellite structure and function. Better techniques must be developed to remove the subsequent heat generated by the active components required to-meet future computing requirements. Integration of commercially available electronics must be achieved without the increased costs normally associated with current generation multi chip modules. In this paper we present a method of component integration that uses silicon heat pipe technology and advanced flexible laminate circuit board technology to achieve thermal control and satellite structure. The' electronics/heat pipe stack then becomes an integral component of the spacecraft structure. Thermal management on satellites has always been a problem. The shrinking size of electronics and voltage requirements and the accompanying reduction in power dissipation has helped the situation somewhat. Nevertheless, the demands for increased onboard processing power have resulted in an ever increasing power density within the satellite body. With the introduction of nano satellites, small satellites under ten kilograms and under 1000 cubic inches, the area available on which to place hot components for proper heat dissipation has dwindled dramatically. The resulting satellite has become nearly a solid mass of electronics with nowhere to dissipate heat to space. The silicon heat pipe is attached to an aluminum frame using a thermally conductive epoxy or solder preform. The frame serves three purposes. First, the aluminum frame provides a heat conduction path from the edge of the heat pipe to radiators on the surface of the satellite. Secondly, it serves as an attachment point for extended structures attached to the satellite such as solar panels, radiators, antenna and.telescopes (for communications or sensors). Finally, the packages make thermal contact to the surface of the silicon heat pipe through soft thermal pads. Electronic components can be placed on both sides of the flexible circuit interconnect. Silicon heat pipes have a number of advantages over heat pipe constructed from other materials. Silicon heat pipes offer the ability to put the heat pipe structure beneath the active components of a processed silicon wafer. This would be one way of efficiently cooling the heat generated by wafer scale integrated systems. Using this technique, all the functions of a satellite could be reduced to a few silicon wafers. The integration of the heat pipe and the electronics would further reduce the size and weight of the satellite.

Gass, K.; Robertson, P.J.; Shul, R.; Tigges, C.

1999-03-30

234

46 CFR 154.503 - Piping and piping system components: Protection from movement.  

Code of Federal Regulations, 2010 CFR

...Shipping 5 2010-10-01 2010-10-01 false Piping and piping system components: Protection from movement. 154...Design, Construction and Equipment Cargo and Process Piping Systems § 154.503 Piping and piping system...

2010-10-01

235

46 CFR 154.503 - Piping and piping system components: Protection from movement.  

Code of Federal Regulations, 2011 CFR

...Shipping 5 2011-10-01 2011-10-01 false Piping and piping system components: Protection from movement. 154...Design, Construction and Equipment Cargo and Process Piping Systems § 154.503 Piping and piping system...

2011-10-01

236

46 CFR 154.503 - Piping and piping system components: Protection from movement.  

Code of Federal Regulations, 2012 CFR

...Shipping 5 2012-10-01 2012-10-01 false Piping and piping system components: Protection from movement. 154...Design, Construction and Equipment Cargo and Process Piping Systems § 154.503 Piping and piping system...

2012-10-01

237

46 CFR 154.503 - Piping and piping system components: Protection from movement.  

Code of Federal Regulations, 2014 CFR

...Shipping 5 2014-10-01 2014-10-01 false Piping and piping system components: Protection from movement. 154...Design, Construction and Equipment Cargo and Process Piping Systems § 154.503 Piping and piping system...

2014-10-01

238

46 CFR 154.503 - Piping and piping system components: Protection from movement.  

Code of Federal Regulations, 2013 CFR

...Shipping 5 2013-10-01 2013-10-01 false Piping and piping system components: Protection from movement. 154...Design, Construction and Equipment Cargo and Process Piping Systems § 154.503 Piping and piping system...

2013-10-01

239

Sounding rocket heat pipe experiment.  

NASA Technical Reports Server (NTRS)

An experiment was conducted during October 1971 aboard a sounding rocket to observe the operation of several heat pipes in a zero gravity environment. The pipe designs which were tested included a spiral artery, a pedestal artery, and a plain groove. Two control pipes without wicking were also flown. The two artery pipes were similar to those which will be used on the OAO-C satellite, while the groove pipe was similar to that used on the ATS-F spacecraft. The results of the experiment indicate that the heat pipes operated satisfactorily during the flight which included four minutes of zero gravity.

Mcintosh, R.; Knowles, G.; Hembach, R. J.

1972-01-01

240

Wedgethread pipe connection  

DOEpatents

Several embodiments of a wedgethread pipe connection are disclosed that have improved makeup, sealing, and non-loosening characteristics. In one embodiment, an open wedgethread is disclosed that has an included angle measured in the gap between the stab flank and the load flank to be not less than zero, so as to prevent premature wedging between mating flanks before the position of full makeup is reached, as does occur between trapped wedgethreads wherein the included angle is less than zero. The invention may be used for pipe threads large or small, as a flush joint, with collars, screwed into plates or it may even be used to reversibly connect such as solid posts to base members where a wide makeup torque range is desired. This Open wedgethread, as opposed to trapped wedgethreads, provides a threaded pipe connection that: is more cost-effective; can seal high pressure gas; can provide selectively a connection strength as high as the pipe strength; assures easy makeup to the desired position of full makeup within a wide torque range; may have a torque strength as high as the pipe torque strength; is easier to manufacture; is easier to gage; and is less subject to handling damage.

Watts, John D.

2003-06-17

241

Remotely operated pipe connector  

DOEpatents

An apparatus for remotely assembling and disassembling a Graylock type coctor between a pipe and a closure for the pipe includes a base and a receptacle on the base for the closure. The pipe is moved into position vertically above the closure by a suitable positioning device such that the flange on the pipe is immediately adjacent and concentric with the flange on the closure. A moving device then moves two semicircular collars from a position free of the closure to a position such that the interior cam groove of each collar contacts the two flanges. Finally, a tensioning device automatically allows remote tightening and loosening of a nut and bolt assembly on each side of the collar to cause a seal ring located between the flanges to be compressed and to seal the closure. Release of the pipe and the connector is accomplished in the reverse order. Preferably, the nut and bolt assembly includes an elongate shaft portion on which a removable sleeve is located.

Josefiak, Leonard J. (Scotia, NY); Cramer, Charles E. (Guilderford, NY)

1988-01-01

242

Explosive Welding of Pipes  

NASA Astrophysics Data System (ADS)

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. 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. Model experiments with pipes having radii R = 57 mm confirmed results of the calculations and the possibility in principle to weld pipes by explosion with use of water as filler. Reduction of pipe diameter after dynamic loading and explosive welding was ˜2%.

Burtseva, Olga

2007-06-01

243

49 CFR 195.114 - Used pipe.  

Code of Federal Regulations, 2010 CFR

...114 Used pipe. Any used pipe installed in a pipeline system...the following: (a) The pipe must be of a known specification... (1) Buckles; (2) Cracks, grooves, gouges, dents...the specification to which the pipe was manufactured; or...

2010-10-01

244

Numerical investigation of the aerodynamic and structural characteristics of a corrugated wing  

Microsoft Academic Search

Previous experimental studies on static, bio-inspired corrugated wings have shown that they produce favorable aerodynamic properties such as delayed stall compared to streamlined wings and flat plates at high Reynolds numbers (Re >= 4x104). The majority of studies have been carried out with scaled models of dragonfly forewings from the Aeshna Cyanea in either wind tunnels or water channels. In

Kyle Hord

2010-01-01

245

RESEARCH ARTICLE An experimental study of a bio-inspired corrugated airfoil  

E-print Network

was conducted to investigate the aerodynamic characteristics of a bio- inspired corrugated airfoil compared at low Reynolds numbers (ReC \\ 100,000). While aerodynamic performance of the smooth-surfaced airfoil and the flat plate would vary con- siderably with the changing of the chord Reynolds num- bers, the aerodynamic

Hu, Hui

246

Classical Theory of Atom Scattering from Corrugated Surfaces W. W. Hayes  

E-print Network

in the collision of an atomic projectile with a surface which is either ordered or disordered. This theory the theory reproduces the well-known eikonal approximation for elastic collisions, provides a simpleClassical Theory of Atom Scattering from Corrugated Surfaces W. W. Hayes Physical Sciences

Manson, Joseph R.

247

A parametric study on the thermal performance of cross-corrugated solar air collectors  

Microsoft Academic Search

A comprehensive parametric study has been carried out in this paper on the thermal performance of cross-corrugated solar air collectors. These collectors consists of a wavelike absorbing plate and a wavelike bottom plate which are crosswise positioned to form the air flow channel. Two types of these collectors are considered. For the Type 1 collector, the wavelike shape of the

Wenxian Lin; Wenfeng Gao; Tao Liu

2006-01-01

248

Scattering by a periodically corrugated interface between free space and a gyroelectromagnetic uniaxial medium  

NASA Astrophysics Data System (ADS)

A formalism is presented to calculate the electromagnetic fields scattered by a periodically corrugated interface made of a material that has uniaxial dielectric and magnetic properties. The method is based on the T-matrix approach originally used for isotropic materials. Although it can handle arbitrary groove shapes it is presumably restricted to shallow gratings with small slopes.

Lakhtakia, Akhlesh; Depine, Ricardo A.; Inchaussandague, Marina E.; Brudny, Vera L.

1993-05-01

249

Design of Broadband Constant-Beamwidth Conical Corrugated-Horn Antennas [Antenna Designer's Notebook  

Microsoft Academic Search

In this paper, a new design procedure is proposed for the design of wideband constant-beamwidth conical corrugated-horn antennas, with minimum design and construction complexity. The inputs to the procedure are the operating frequency band, the required minimum beamwidth in the entire frequency band, and the frequency in which the maximum gain is desired to occur. Based on these values, the

Majid Abbas-Azimi; Farhad Mazlumi; Fereidoon Behnia

2009-01-01

250

Optimizing a corrugated horn for telecommunication and tracking missions using a new flexible horn design software  

Microsoft Academic Search

A new design approach and an associated software tool for conical corrugated horn antennas has been developed in a joint TICRA-Thales Alenia Space-ESA project. The software is developed such that it supports the user in designing an optimized horn antenna in a natural way with stepwise refinements both in geometry, in optimization parameters selection and in design requirements definition. The

J. Pressense; P. E. Frandsen; M. Lumholt; F. Delepaux; A. Frandsen; L. Salghetti Drioli

2010-01-01

251

Bragg spectroscopy for measuring Casimir-Polder interactions with Bose-Einstein condensates above corrugated surfaces  

E-print Network

We propose a method to probe dispersive atom-surface interactions by measuring via two-photon Bragg spectroscopy the dynamic structure factor of a Bose-Einstein condensate above corrugated surfaces. This method takes advantage of the condensate coherence to reveal the spatial Fourier components of the lateral Casimir-Polder interaction energy.

Gustavo A. Moreno; Diego A. R. Dalvit; Esteban Calzetta

2010-03-11

252

Structural performance of near-optimal sandwich panels with corrugated cores  

Microsoft Academic Search

An experimental and computational study of the bending response of steel sandwich panels with corrugated cores in both transverse and longitudinal loading orientations has been performed. Panel designs were chosen on the basis of failure mechanism maps, constructed using analytic models for failure initiation. The assessment affirms that the ana- lytic models provide accurate predictions when failure initiation is controlled

L. Valdevit; Z. Wei; C. Mercer; F. W. Zok; A. G. Evans

2005-01-01

253

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

E-print Network

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.

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

2014-06-16

254

Thermal performance of integrated collector storage solar water heater with corrugated absorber surface  

Microsoft Academic Search

An investigation is reported of the thermal performance of an integrated solar water heater with a corrugated absorber surface. The thermal performance of the rectangular collector\\/storage solar water heater depends significantly on the heat transfer rate between the absorber surface and the water, and on the amount of solar radiation incident on the absorber surface. In this investigation, the surface

Rakesh Kumar; Marc A. Rosen

2010-01-01

255

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

DOEpatents

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.

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

256

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

Microsoft Academic Search

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

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

2009-01-01

257

Pressure and heating-rate distributions on a corrugated surface in a supersonic turbulent boundary layer  

NASA Technical Reports Server (NTRS)

Drag and heating rates on wavy surfaces typical of current corrugated plate designs for thermal protection systems were determined experimentally. Pressure-distribution, heating-rate, and oil-flow tests were conducted in the Langley Unitary Plan wind tunnel at Mach numbers of 2.4 and 4.5 with the corrugated surface exposed to both thick and thin turbulent boundary layers. Tests were conducted with the corrugations at cross-flow angles from 0 deg to 90 deg to the flow. Results show that for cross-flow angles of 30 deg or less, the pressure drag coefficients are less than the local flat-plate skin-friction coefficients and are not significantly affected by Mach number, Reynolds number, or boundary-layer thickness over the ranges investigated. For cross-flow angles greater than 30 deg, the drag coefficients increase significantly with cross-flow angle and moderately with Reynolds number. Increasing the Mach number causes a significant reduction in the pressure drag. The average and peak heating penalties due to the corrugated surface are small for cross-flow angles of 10 deg or less but are significantly higher for the larger cross-flow angles.

Sawyer, J. W.

1977-01-01

258

Spatial structure of the flow in a channel with corrugated wall  

NASA Astrophysics Data System (ADS)

Results of visual studies of the flow structure of the air jet in a channel with corrugated wall are presented. The studies have been carried out in the laminar and turbulent flows. The typical large-scale structures and zones of intensive turbulent mixing have been determined in the flow. The general scheme of the flow is suggested.

Perepelitsa, B. V.

2010-12-01

259

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

NASA Astrophysics Data System (ADS)

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.

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

2013-03-01

260

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

E-print Network

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...

Aiyalur Shankaran, Rohit

2008-10-10

261

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

E-print Network

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...

Aiyalur Shankaran, Rohit

2009-05-15

262

Results of measurements at a laboratory condensation heat exchanger with a corrugated minichanel tube  

NASA Astrophysics Data System (ADS)

This article present a short selection of results obtained from measurements done at a laboratory condensation heat-exchanger with a corrugated mini-channel tube. It also touches a little the metering method and design of the heat-exchanger.

Pavel, Peukert; Jan, Hrubý

2012-04-01

263

Convective heat transfer and pressure drop in V-corrugated channel with different phase shifts  

NASA Astrophysics Data System (ADS)

New energy system development and energy conservation require high performance heat exchanger, so the researchers are seeking to find new methods to enhance heat transfer mechanism in heat exchangers. The objectives of this study are investigating heat transfer performance and flow development in V-corrugated channels, numerical simulations were carried out for uniform wall heat flux equal 290 W/m2 using air as a working fluid, Reynolds number varies from 500 to 2,000, phase shifts, 0° < Ø < 180°, and channel heights (S = 12.5, 15.0, 17.5 and 20 mm). Governing equations of flow and energy were solved numerically by using finite volume method. The numerical results indicated that, wavy (V-corrugated) channels have a significant impact on heat transfer enhancement with increase in pressure drop though channel due to breaking and destabilizing in the thermal boundary layer are occurred as fluid flowing through the corrugated surfaces and the effect of corrugated phase shift on the heat transfer and fluid flow is more significant in narrow channel, the goodness factor (j/f) was increased with increasing channel phase shift, the best performance was noticed on phase shift, Ø = 180° and channel height, S = 12.5 mm.

Sakr, Mohamed

2015-01-01

264

Corrugated waveguide slow-wave structure for THz travelling wave tube  

Microsoft Academic Search

THz applications require sources and amplifiers compact, lightweight and powerful. Vacuum electron devices are the candidate solution. Among others, the corrugated waveguide slow-wave structure seems particularly suitable for traveling wave tubes in the THz region. THz vacuum electron devices require high precision technological processes with high aspect ratio such as SU-8 process. However, fabrication tolerances could highly affect the overall

Mauro Mineo; Claudio Paoloni; Aldo Di Carlo; Anna Maria Fiorello; Massimiliano Dispenza

2009-01-01

265

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

DOEpatents

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.

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

1984-04-10

266

Scattering of xenon from Ni,,111...: Collision-induced corrugation and energy transfer dynamics  

E-print Network

Scattering of xenon from Ni,,111...: Collision-induced corrugation and energy transfer dynamics in which a beam of xenon atoms collides with a clean Ni 111 surface, and the speed and angular is independent of initial and final scattering angles. This result is attributed to multiple xenon

Zare, Richard N.

267

Heat pipes and use of heat pipes in furnace exhaust  

DOEpatents

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.

Polcyn, Adam D. (Pittsburgh, PA)

2010-12-28

268

Apparatus for moving a pipe inspection probe through piping  

DOEpatents

A method and apparatus 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.

Zollinger, W. Thor (Martinez, GA); Appel, D. Keith (Aiken, SC); Lewis, Gregory W. (North Augusta, SC)

1995-01-01

269

Apparatus for moving a pipe inspection probe through piping  

DOEpatents

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.

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

1995-07-18

270

Heat Pipe Technology  

NASA Technical Reports Server (NTRS)

The heat pipe, a sealed chamber whose walls are lined with a "wick," a thin capillary network containing a working fluid in liquid form was developed for a heat distribution system for non-rotating satellites. Use of the heat pipe provides a continuous heat transfer mechanism. "Heat tubes" that improve temperature control in plastics manufacturing equipment incorporated the heat pipe technology. James M. Stewart, an independent consultant, patented the heat tubes he developed and granted a license to Kona Corporation. The Kona Nozzle for heaterless injection molding gets heat for its operation from an external source and has no internal heating bands, reducing machine maintenance and also eliminating electrical hazards associated with heater bands. The nozzles are used by Eastman Kodak, Bic Pen Corporation, Polaroid, Tupperware, Ford Motor Company, RCA, and Western Electric in the molding of their products.

1981-01-01

271

Heat-pipe Earth.  

PubMed

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

Moore, William B; Webb, A Alexander G

2013-09-26

272

Apparatus for inspecting piping  

DOEpatents

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.

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

1995-03-21

273

Apparatus for inspecting piping  

DOEpatents

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.

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

1995-01-01

274

Heat pipe array heat exchanger  

DOEpatents

A heat pipe arrangement for exchanging heat between two different temperature fluids. The heat pipe arrangement is in a ounterflow relationship to increase the efficiency of the coupling of the heat from a heat source to a heat sink.

Reimann, Robert C. (Lafayette, NY)

1987-08-25

275

Tippy Tap Plus Piping  

NSDL National Science Digital Library

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.

Integrated Teaching and Learning Program, College of Engineering, University of Colorado at Boulder,

276

Heat transfer in pipes  

NASA Technical Reports Server (NTRS)

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.

Burbach, T.

1985-01-01

277

Heat pipe cooled probe  

NASA Technical Reports Server (NTRS)

The basic heat pipe principle is employed to provide a self-contained passively cooled probe that may be placed into a high temperature environment. The probe consists of an evaporator region of a heat pipe and a sensing instrument. Heat is absorbed as the working fluid evaporates in the probe. The vapor is transported to the vapor space of the condenser region. Heat is dissipated from the condenser region and fins causing condensation of the working fluid, which returns to the probe by gravity and the capillary action of the wick. Working fluid, wick and condenser configurations and structure materials can be selected to maintain the probe within an acceptable temperature range.

Camarda, C. J. (inventor); Couch, L. M.

1984-01-01

278

Pipe Drafting with CAD. Teacher Edition.  

ERIC Educational Resources Information Center

This teacher's guide contains nine units of instruction for a course on computer-assisted pipe drafting. The course covers the following topics: introduction to pipe drafting with CAD (computer-assisted design); flow diagrams; pipe and pipe components; valves; piping plans and elevations; isometrics; equipment fabrication drawings; piping design…

Smithson, Buddy

279

Piping-System Solutions Using Mathcad  

E-print Network

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

Kostic, Milivoje M.

280

Automated internal pipe cutting device  

Microsoft Academic Search

The invention is a remotely controlled internal pipe cutting device primarily used for cutting pipes where the outside of the pipe is inaccessible at the line where the cut is to be made. The device includes an axial ram within a rotational cylinder which is enclosed in a housing. The housing is adapted for attachment to an open end of

William J. Godlewski; Gary S. Haffke; Dale Purvis; Ronald W. Bashar; Stewart D. Jones; Moretti Jr. Henry; James Pimentel

2003-01-01

281

Pipe Flow System Holly Guest  

E-print Network

Pipe Flow System Design Holly Guest #12;Problem · An engineer is asked to compute the flow rate of a given pipe system involving two reservoirs and to make recommendations based on the outputs on how to improve the design. · Inputs include: · Head of each reservoir · Head of the pump · Pipe Diameter using

Clement, Prabhakar

282

Transient flow in pipe networks  

Microsoft Academic Search

In order to apply the fixed-grid method of characteristics to transient flow in multi-pipe systems, some pipe reaches may not satisfy the Courant condition. Various numerical techniques can be applied for these reaches. In the present study, the finite difference or interpolation techniques are coupled with the method of characteristics. The location of the disproportionate pipe, which does not satisfy

Hossein M. V. Sam Ani; Alireza Khayatzadeh

2002-01-01

283

High pressure steam pipe  

Microsoft Academic Search

A detailed dynamic analysis, presented in a series of reports, was conducted on the seismic response and structural safety of key subsystems (steam generator, high pressure steam piping, coal handling equipment, cooling tower, chimney) of Unit No. 3 of TVA at Paradise, Kentucky in order to: (1) determine for the key components the natural frequencies below 50 Hz and the

C. T. Sun; A. S. Ledger; H. Lo

1976-01-01

284

Piping stress handbook  

Microsoft Academic Search

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

Heiguero

1985-01-01

285

Heat pipe investigations  

NASA Technical Reports Server (NTRS)

Techniques associated with thermal-vacuum and bench testing, along with flight testing of the OAO-C spacecraft heat pipes are outlined, to show that the processes used in heat transfer design and testing are adequate for good performance evaluations.

Marshburn, J. P.

1973-01-01

286

Pipe connector. [LMFBR  

Microsoft Academic Search

A safety test facility for testing sodium-cooled nuclear reactor components includes a reactor vessel and a heat exchanger submerged in sodium in the tank. The reactor vessel and heat exchanger are connected by an expansion\\/deflection pipe coupling comprising a pair of coaxially and slidably engaged tubular elements having radially enlarged opposed end portions of which at least a part is

T. E. Sullivan; J. A. Pardini

1976-01-01

287

The effects of corrugation and wing planform on the aerodynamic force production of sweeping model insect wings  

Microsoft Academic Search

The effects of corrugation and wing planform (shape and aspect ratio) on the aerodynamic force production of model insect\\u000a wings in sweeping (rotating after an initial start) motion at Reynolds number 200 and 3500 at angle of attack 40 are investigated,\\u000a using the method of computational fluid dynamics. A representative wing corrugation is considered. Wing-shape and aspect ratio\\u000a (AR) of

Guoyu Luo; Mao Sun

2006-01-01

288

Long-term aging of fiber-cement corrugated sheets – The effect of carbonation, leaching and acid rain  

Microsoft Academic Search

This paper studies the performance of fiber-cement corrugated sheets exposed to long-term weathering, exploring the effect of different environments on fiber-cement degradation. Fiber-cement corrugated sheets that had been exposed to weathering, and in place for more than 30-years, were collected from two different Brazilian cities (São Paulo and Criciúma). Mechanical properties (MOR, MOE and fracture toughness) were tested on samples

C. M. R. Dias; M. A. Cincotto; H. Savastano Jr; V. M. John

2008-01-01

289

A Comparative Study of the Thermal Performances of Cross-Corrugated and V-Groove Solar Air Collectors  

Microsoft Academic Search

In this paper, the thermal performance of cross-corrugated and v-groove solar air collectors has been compared under a wide range of configuration and operating conditions. For cross-corrugated collectors, the air flow channel is formed by the wavelike absorbing plate and the wavelike bottom plate, which are transversely positioned, whereas for v-groove collectors it is formed by the v-groove absorbing plate

Tao Liu; Wenxian Lin; Wenfeng Gao; Chaofeng Xia

2007-01-01

290

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

DOEpatents

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.

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

1984-04-10

291

Experimental investigation on the convective heat transfer enhancement for highly viscous fluids in helical coiled corrugated tubes  

NASA Astrophysics Data System (ADS)

In the present analysis, the forced convective heat transfer in smooth and corrugated helical coiled tubes was experimentally studied in the Reynolds and Dean number ranges 50÷1200 and 12÷295 respectively, by adopting Ethylene Glycol as working fluid. The primary aim of the investigation is to study the combined effect of the wall curvature and of the wall corrugation in the thermal entrance region for highly viscous fluids. Two coiled tubes with a curvature ratio of about 0.06, one with smooth wall and the other with spirally corrugated wall, were investigated under the uniform heat flux boundary condition. The main conclusion is that in the Reynolds number range analyzed, both curvature and corrugation enhance the heat transfer. For Dean number values lower than about 120 the wall curvature effect prevails, and the heat transfer enhancement reflects Nusselt numbers that are approximately 2-3 times higher than the straight smooth section. For greater Dean number values, the wall corrugation instead prevails. In fact the corrugated coiled tube reaches Nusselt number values which are up to 8 times higher than the ones expected for the smooth straight tube. The smooth coiled tube shows instead thermal performances at maximum 3.6 times over the straight section.

Rainieri, S.; Bozzoli, F.; Cattani, L.; Pagliarini, G.

2012-11-01

292

Enhanced efficiency of organic light-emitting devices by employing a periodically corrugated conductive photoresist  

NASA Astrophysics Data System (ADS)

Photons trapped in the form of waveguide (WG) modes associated with the organic/organic interface and in the form of surface plasmon polariton (SPP) modes associated with the metallic electrode/organic interface result in a large energy loss in organic light-emitting devices (OLEDs). We demonstrate the efficient outcoupling of WG and SPP modes by integrating a wavelength-scale periodically corrugated conductive photoresist into the device structure. The corrugated OLEDs with appropriate grating periods lead to a 15.9% increase in efficiency compared with the planar OLEDs. The efficient outcoupling of the WG and SPP modes is verified by the numerical simulation of both the emission spectra and the field distribution.

Bai, Yu; Fan, Yi; Lu, Qipeng; Wang, Xiaoyi; Chu, Minghui; Liu, Xingyuan

2015-02-01

293

Corrugation reduction in periodically inverted GaAs by molecular beam epitaxy growth using arsenic dimers  

NASA Astrophysics Data System (ADS)

Molecular beam epitaxy (MBE) regrowth of GaAs on periodically inverted GaAs(100) substrates using arsenic dimers (As2) was studied. We found that we can reduce corrugations on the regrown GaAs by MBE growth using As2 at considerably higher substrate temperatures (˜450 °C) than in the case of growth using arsenic tetramers (˜300 °C). This result indicates that As2 MBE regrowth can be used to fabricate highly efficient GaAs/AlGaAs wavelength conversion waveguiding devices owing to a reduction in the propagation losses caused by interface corrugations. We also estimated the diffusion lengths of Ga atoms coexisting with As2 on GaAs(100) surfaces from experimental thickness variations on the basis of a diffusion equation analysis.

Narasaki, Ryota; Matsushita, Tomonori; Kondo, Takashi

2015-02-01

294

Dynamics of corrugated interfaces of solidifying eutectics: flow-modified morphologies  

NASA Astrophysics Data System (ADS)

Fluid motions impressed upon the interfaces of eutectic crystals in directional solidification result in a coarsening effect on the lamellar spacing. This flow-induced change of microstructures and the interfacial dynamics are analyzed using boundary-layer theory plus a method that homogenizes the interfacial corrugations. The resulting system describes the behavior of average crystal fronts, and predicts the evolution of trijunction points where liquid and two solid phases meet. We find that in a weak-flow regime lamellar width at the minimum undercooling has a scaling similar to Jackson-Hunt's but modified by the flow effect. When the flows are strong, a new scaling law is obtained such that the width is proportional to one-fourth power of the imposed flow-strength. Lamellar phases are then tilted with respect to their growth direction with interfacial corrugations moving against the flows. Evolution of the average moving fronts is studied in the weakly nonlinear regime.

Chen, Yi-Ju; Davis, Stephen H.

2000-11-01

295

A performance-enhanced energy harvester for low frequency vibration utilizing a corrugated cantilevered beam  

NASA Astrophysics Data System (ADS)

This note proposes a performance-enhanced piezoelectric energy harvester by replacing a conventional flat cantilevered beam with a corrugated beam. It consists of a proof mass and a sinusoidally or trapezoidally corrugated cantilevered beam covered by a polyvinylidene fluoride (PVDF) film. Compared to the conventional energy harvester of the same size, it has a more flexible bending stiffness and a larger bonding area of the PVDF layer, so higher output voltage from the device can be expected. In order to investigate the characteristics of the proposed energy harvester, analytical developments and numerical simulations on its natural frequency and tip displacement are carried out. Shaking table tests are also conducted to verify the performance of the proposed device. It is clearly shown from the tests that the proposed energy harvester not only has a lower natural frequency than an equivalent sized standard energy harvester, but also generates much higher output voltage than the standard one.

Kim, In-Ho; Jin, SeungSeop; Jang, Seon-Jun; Jung, Hyung-Jo

2014-03-01

296

Drill pipe protector development  

SciTech Connect

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.

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

297

Explosive welding of pipes  

NASA Astrophysics Data System (ADS)

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. 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. Model experiments with pipes having radii R = 57 mm confirmed results of the calculations and the possibility in principle to weld pipes by explosion with use of water as filler.

Drennov, O.; Burtseva, O.; Kitin, A.

2006-08-01

298

Pipe cleaning machine  

Microsoft Academic Search

This is a semiautomatic machine for removing rust, mud, and paraffin from the interior and exterior of well pipe or tubing to recondition it for further use. Loading, cleaning and re-racking is carried out by a single operator. The machine has a rectangular, box-like frame which consists of 3 sub-sections and includes a loading rack located on one side of

1965-01-01

299

Electrohydrodynamic heat pipe research  

NASA Technical Reports Server (NTRS)

Experimental and theoretical applications to electrohydrodynamic heat pipe (EHDHP) research are presented. Two problems in the research which are discussed are the prediction of the effective thermal conductance of an EHDHP with threaded grooves for fluid distribution to the evaporator of an EHDHP. Hydrodynamic equations are included along with a discussion of boundary conditions and burn-out conditions. A discussion of the theoretical and experimental results is presented.

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

1973-01-01

300

Corrugation-pitch-modulated DFB semiconductor lasers realized by common holographic exposure  

NASA Astrophysics Data System (ADS)

Experimental results of corrugation-pitch-modulated (CPM) DFB lasers with distributed phase shift (DPS) based on reconstruction-equivalent-chirp (REC) technique are demonstrated. The DPS can flatten the light intensity distribution along the laser cavity and reduce the spatial hole burning (SHB). The lasers have good single longitudinal mode (SLM) property even under high injection current. Thanks to the sampling technique, the grating can be easily fabricated by holographic exposure and conventional lithograph.

Li, Simin; Li, Lianyan; Shi, Yuechun; Cao, Baoli; Guo, Renjia; Zheng, Junshou; Chen, Xiangfei

2014-07-01

301

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

E-print Network

but are not limited to the following: • Paper is steam heated to form the linerboards (outer layers of cardboard) • Paper is steam heated and corrugated to form the ?medium? of the cardboard • Top and bottom linerboards have adhesive (glue) applied... to and attached with ?medium? to form cardboard • Cardboard is pressed together with hot plates to remove excess moisture and to allow the glue to set. • Slitters cut the cardboard to desired lengths and widths and add score lines for folding. The back...

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

2005-01-01

302

Effect of board density on bending properties and dimensional stabilities of MDF-reinforced corrugated particleboard  

Microsoft Academic Search

We investigated the bending properties of composite boards produced by reinforcing both sides of corrugated particleboard with medium-density fiberboard (MDF). Thickness swelling and linear expansion (LE) were measured to assess the dimensional stabilities of the composite board. Although the apparent density of the composite board was 0.48?g\\/cm 3, its strength was found to be equivalent to that of 18-type particleboard

Koji Hayashi; Masaharu Ohmi; Hiroshi Tominaga; Kiyoharu Fukuda

2003-01-01

303

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

304

Experimental studies of quasi-longitudinal waves power flow in corrugated plates  

Microsoft Academic Search

The structural intensity technique using cross-spectral densities is used to estimate the quasi-longitudinal wave power in rectangular and trapezoidal corrugated plates in the frequency domain. The two-point transducer method for in-plane power in naturally orthotropic plate, whose thickness is uniform, is used for measuring in-plane vibration power transmission of these plates. The method of elastic equivalence is used to facilitate

Nirmal Kumar Mandal

2006-01-01

305

FINITE ELEMENT MODELING OF RADIAL CORRUGATED TUBULAR COMPOSITE STRUCTURE UNDER AXIAL LOADING  

Microsoft Academic Search

The present paper deals with the implementation of the finite element code Altair HyperWorks of RADIOSS\\/Explicit version 10.0 to simulate the crash behavior and energy absorption characteristics of composite of cotton fiber tubes of radial corrugation cross-section subjected to high velocity of axial impact loading. The collapse procedure is successfully simulated and the verification of numerical model was compared with

Akbar Othman; Azrol Jailani; Mohd Zaidi

2012-01-01

306

Calculation of process parameters in the manufacture of a panel with a corrugated core  

NASA Astrophysics Data System (ADS)

A method is presented for calculating the parameters of a process for producing multilayer curved panels with a lightweight corrugated core. The method provides a way to achieve precision in panel manufacture by shaping the core in accordance with the required curvature during the forming of the core. The structure and the density of the core can be varied in accordance with the desired functional application of the panels.

Khaliulin, V. I.; Desiatov, V. E.

307

Highly efficient antenna system using a corrugated horn and scanning hyperbolic reflector  

NASA Technical Reports Server (NTRS)

In a horn-reflector antenna system for producing a spherical aperture phase front, a corrugated conical horn illuminates a section of a hyperbolic reflector to produce a spherical aperture phase front. This front produces a far field beam with low sidelobes and high beam efficiency. The system is insensitive to frequency and polarization changes, and is also insensitive to orientation about the axis of the conical horn for beam scanning.

Green, K. A. (inventor)

1976-01-01

308

Phase space tomography of cold-atom dynamics in a weakly corrugated potential  

NASA Astrophysics Data System (ADS)

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.

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

2014-09-01

309

Ohmic losses in coaxial resonators with longitudinal inner-outer corrugation  

SciTech Connect

In this paper, a coaxial resonator with longitudinal inner-outer corrugation is introduced. Its eigen-equation and expression of ohmic losses are derived. Ohmic losses in the cavity are investigated. Results show that ohmic losses in the outer and inner conductors share a similar variation trend, while the former is larger than the later. What's more, changes of the inner and outer slot depth and width induce different variations of ohmic losses on the surface of the inner and outer conductors.

Shenyong Hou, A. [Terahertz Science and Technology Research Center, University of Electronics Science and Technology of China, Chengdu 610054 (China) [Terahertz Science and Technology Research Center, University of Electronics Science and Technology of China, Chengdu 610054 (China); Yangtze Normal University, Chongqing 408001 (China); Sheng Yu, B.; Hongfu Li, C.; Qixiang Zhao, D. [Terahertz Science and Technology Research Center, University of Electronics Science and Technology of China, Chengdu 610054 (China)] [Terahertz Science and Technology Research Center, University of Electronics Science and Technology of China, Chengdu 610054 (China); Xiang Li, E. [Terahertz Science and Technology Research Center, University of Electronics Science and Technology of China, Chengdu 610054 (China) [Terahertz Science and Technology Research Center, University of Electronics Science and Technology of China, Chengdu 610054 (China); Queen Mary University of London, London E1 4NS (United Kingdom)

2013-05-15

310

Guidable pipe plug  

DOEpatents

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.

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

2001-01-01

311

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

NASA Technical Reports Server (NTRS)

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.

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

1985-01-01

312

Effect of an electric field on film flow down a corrugated wall at zero Reynolds number  

NASA Astrophysics Data System (ADS)

The effect of an electric field on a liquid layer flowing down an inclined, corrugated wall at zero Reynolds number is investigated. The layer is taken to be either a perfect conductor or a perfect dielectric. The region above the layer is assumed to be a perfect dielectric. Steady flow down a wall with small-amplitude sinusoidal corrugations is considered, and it is shown how the electric field can be used to control the amplitude of the free-surface deflection and the phase shift between the free surface and the wall profile. Steady flow over walls with large amplitude sinusoidal corrugations or other-shaped indentations is studied by using the boundary-element method. Results for flow into a wide rectangular trench are compared to previous model predictions based on the lubrication approximation. For a perfect-conductor film, the results confirm that the height of the capillary ridge, which appears above a downward step, monotonically decreases as the electric field strength increases. Solutions for a perfect-dielectric film with relative permittivity larger than unity are similar to those for a perfect-conductor film, although the height of the capillary ridge nonmonotonically varies with the electric field strength. The behavior of the solutions for a perfect-dielectric film with relative permittivity less than unity is qualitatively different. The height of the capillary ridge monotonically increases as the electric field strength increases. Flows into narrow trenches and over narrow mounds are also computed.

Tseluiko, D.; Blyth, M. G.; Papageorgiou, D. T.; Vanden-Broeck, J.-M.

2008-04-01

313

Investigations of heat transfer and friction characteristics of compact cross-corrugated recuperators  

NASA Astrophysics Data System (ADS)

As one of the key devices in the high temperature gas turbine system, cross-corrugated recuperators provide high heat transfer capabilities with compact size, light weight, strong mechanical strength and are mandatory to achieve 30 % electrical efficiency or higher for micro turbine engines. Flow in such geometries is usually laminar with lower Reynolds numbers. In order to understand mechanisms of flowing and heat transfer, periodic fully developed fluid flow and heat transfer in two types of cross-corrugated structures with inclination angle at 90° are investigated numerically and experimentally. Periodicity was used to reduce the complexity of the channel geometry and enables the smallest possible segment of the flow channel to be modeled. The velocity and temperature distributions were obtained in the three-dimensional complex domain. Besides a detailed flow analysis, comparison of the local heat and mass transfer and the pressure losses for these geometries are presented. It is shown that the flow phenomena caused by the different geometries were of significant influence on the homogeneity and on the quantity of the local heat and mass transfer as well as on the pressure drop. As a recuperator for micro turbine engines, cross-corrugated sinusoidal channels are more preferable to triangular channels.

Zhou, Guo-Yan; Tu, Shan-Tung; Ma, Hu-gen

2014-09-01

314

Corrugated Waveguide and Directional Coupler for CW 250-GHz Gyrotron DNP Experiments  

PubMed Central

A 250-GHz corrugated transmission line with a directional coupler for forward and backward power monitoring has been constructed and tested for use with a 25-W continuous-wave gyrotron for dynamic nuclear polarization (DNP) experiments. The main corrugated line (22-mm internal diameter, 2.4-m long) connects the gyrotron output to the DNP probe input. The directional coupler, inserted approximately midway, is a four-port crossed waveguide beamsplitter design. Two beamsplitters, a quartz plate and ten-wire array, were tested with output coupling of 2.5% (?16 dB) at 250.6 GHz and 1.6% (?18 dB), respectively. A pair of mirrors in the DNP probe transferred the gyrotron beam from the 22-mm waveguide to an 8-mm helically corrugated waveguide for transmission through the final 0.58-m distance inside the NMR magnet to the sample. The transmission-line components were all cold tested with a 248 ± 4-GHz radiometer. A total insertion loss of 0.8 dB was achieved for HE11 -mode propagation from the gyrotron to the sample with only 1% insertion loss for the 22-mm-diameter waveguide. A clean Gaussian gyrotron beam at the waveguide output and reliable forward power monitoring were achieved for many hours of continuous operation. PMID:17901907

Woskov, Paul P.; Bajaj, Vikram S.; Hornstein, Melissa K.; Temkin, Richard J.; Griffin, Robert G.

2007-01-01

315

Heat pipe technology: A bibliography with abstracts  

NASA Technical Reports Server (NTRS)

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.

1971-01-01

316

46 CFR 76.33-15 - Piping.  

Code of Federal Regulations, 2013 CFR

...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...

2013-10-01

317

Page 1 of 1 Pipe School  

E-print Network

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

Texas at Arlington, University of

318

46 CFR 76.33-15 - Piping.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 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...

2010-10-01

319

46 CFR 76.33-15 - Piping.  

Code of Federal Regulations, 2014 CFR

...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...

2014-10-01

320

46 CFR 76.33-15 - Piping.  

Code of Federal Regulations, 2012 CFR

...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...

2012-10-01

321

46 CFR 76.33-15 - Piping.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 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...

2011-10-01

322

Insulating Cryogenic Pipes With Frost  

NASA Technical Reports Server (NTRS)

Crystallized water vapor fills voids in pipe insulation. Small, carefully controlled amount of water vapor introduced into dry nitrogen gas before it enters aft fuselage. Vapor freezes on pipes, filling cracks in insulation. Ice prevents gaseous nitrogen from condensing on pipes and dripping on structure, in addition to helping to insulate all parts. Industrial applications include large refrigeration plants or facilities that use cryogenic liquids.

Stephenson, J. G.; Bova, J. A.

1985-01-01

323

Study of near-source earthquake effects on flexible buried pipes  

NASA Astrophysics Data System (ADS)

An investigation is carried out, using strong ground motion recordings, field measurements, and new analytical models, on large diameter flexible buried pipes shaken in the 1994 Northridge earthquake near field. Case studies are presented for corrugated metal pipes (CMP) in the Van Norman Complex (VNC) vicinity in Los Angeles, California. In 1994 the VNC yielded an unprecedented number of strong motion recordings with high acceleration and velocity. These recordings contain forward directivity pulses and provided the largest velocity ever instrumentally recorded (180 cm/s). The recorded motions were significantly different in the longitudinal and transverse directions and had approximately half the amplitude at the VNC center than on the north and south ends. The seismic performances of 61 underground CMPs are presented, beginning with detailed studies of a 2.4 m diameter pipe that suffered complete lateral buckling collapse at the Lower San Fernando Dam (LSFD). The case histories identify factors controlling large diameter CMP seismic performances that are incorporated into several newly developed models for the analysis and design of buried structures. Each model progressively improves the understanding of buried pipe behavior. Simple acceleration- and strain-based pseudo-static models are initially developed to identify main causes for CMP damage. Elasto-dynamic models for transverse SV waves are later used to understand flexible pipe response in the frequency and time domains and are compared with existing solutions. Finally, pseudo-static models, which analyze pipe responses in terms of free-field strains, are formulated to account for dynamic amplification, non-vertical wave incidence, soil layering, and trench backfill soil stiffness. The elastic models are used to investigate soil-pipe interface shear stress and non-linear soil behavior and show that the maximum pipe hoop force is best characterized by assuming no interface slippage. The models explain the observed CMP performance during the 1994 earthquake and show that peak velocity is a more reliable index of flexible pipe damage than acceleration and that large seismic stresses, modulus reduction, and pore pressure increases in the embedding soils damaged the LSFD and other CMPs. Results of the field investigations and companion analyses are useful for the seismic design and strengthening of underground structures.

Davis, Craig Alan

2000-10-01

324

Thermostructural applications of heat pipes  

NASA Technical Reports Server (NTRS)

The feasibility of integrating heat pipes in high temperature structure to reduce local hot spot temperature was evaluated for a variety of hypersonic aerospace vehicles. From an initial list of twenty-two potential applications, the single stage to orbit wing leading edge showed the greatest promise and was selected for preliminary design of an integrated heat pipe thermostructural system. The design consisted of a Hastelloy X assembly with sodium heat pipe passages aligned normal to the wing leading edge. A d-shaped heat pipe cross section was determined to be optimum from the standpoint of structural weight.

Peeples, M. E.; Reeder, J. C.; Sontag, K. E.

1979-01-01

325

Cryogenic Heat Pipe Experiment (CRYOHP)  

NASA Technical Reports Server (NTRS)

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.

Mcintosh, Roy

1992-01-01

326

A Multifrequency Notch Filter for Millimeter Wave Plasma Diagnostics based on Photonic Bandgaps in Corrugated Circular Waveguides  

NASA Astrophysics Data System (ADS)

Sensitive millimeter wave diagnostics need often to be protected against unwanted radiation like, for example, stray radiation from high power Electron Cyclotron Heating applied in nuclear fusion plasmas. A notch filter based on a waveguide Bragg reflector (photonic band-gap) may provide several stop bands of defined width within up to two standard waveguide frequency bands. A Bragg reflector that reflects an incident fundamental TE11 into a TM1n mode close to cutoff is combined with two waveguide tapers to fundamental waveguide diameter. Here the fundamental TE11 mode is the only propagating mode at both ends of the reflector. The incident TE11 mode couples through the taper and is converted to the high order TM1n mode by the Bragg structure at the specific Bragg resonances. The TM1n mode is trapped in the oversized waveguide section by the tapers. Once reflected at the input taper it will be converted back into the TE11 mode which then can pass through the taper. Therefore at higher order Bragg resonances, the filter acts as a reflector for the incoming TE11 mode. Outside of the Bragg resonances the TE11 mode can propagate through the oversized waveguide structure with only very small Ohmic attenuation compared to propagating in a fundamental waveguide. Coupling to other modes is negligible in the non-resonant case due to the small corrugation amplitude (typically 0.05·?0, where ?0 is the free space wavelength). A Bragg reflector for 105 and 140 GHz was optimized by mode matching (scattering matrix) simulations and manufactured by SWISSto12 SA, where the required mechanical accuracy of ± 5 ?m could be achieved by stacking stainless steel rings, manufactured by micro-machining, in a high precision guiding pipe. The two smooth-wall tapers were fabricated by electroforming. Several measurements were performed using vector network analyzers from Agilent (E8362B), ABmm (MVNA 8-350) and Rohde&Schwarz (ZVA24) together with frequency multipliers. The stop bands around 105 GHz (- 55dB) and 140 GHz (-60dB) correspond to the TE11-TM12 and TE11-TM13 Bragg resonances. Experiments are in good agreement with theory.

Wagner, D.; Bongers, W.; Kasparek, W.; Leuterer, F.; Monaco, F.; Münich, M.; Schütz, H.; Stober, J.; Thumm, M.; Brand, H. v. d.

2015-03-01

327

14 CFR 27.1123 - Exhaust piping.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Exhaust piping. 27.1123 Section 27.1123 Aeronautics...Powerplant Exhaust System § 27.1123 Exhaust piping. (a) Exhaust piping must be heat and corrosion resistant, and...

2013-01-01

328

14 CFR 29.1123 - Exhaust piping.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Exhaust piping. 29.1123 Section 29.1123 Aeronautics...Powerplant Exhaust System § 29.1123 Exhaust piping. (a) Exhaust piping must be heat and corrosion resistant, and...

2011-01-01

329

14 CFR 29.1123 - Exhaust piping.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Exhaust piping. 29.1123 Section 29.1123 Aeronautics...Powerplant Exhaust System § 29.1123 Exhaust piping. (a) Exhaust piping must be heat and corrosion resistant, and...

2010-01-01

330

14 CFR 27.1123 - Exhaust piping.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Exhaust piping. 27.1123 Section 27.1123 Aeronautics...Powerplant Exhaust System § 27.1123 Exhaust piping. (a) Exhaust piping must be heat and corrosion resistant, and...

2010-01-01

331

14 CFR 29.1123 - Exhaust piping.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Exhaust piping. 29.1123 Section 29.1123 Aeronautics...Powerplant Exhaust System § 29.1123 Exhaust piping. (a) Exhaust piping must be heat and corrosion resistant, and...

2013-01-01

332

14 CFR 29.1123 - Exhaust piping.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 2012-01-01 false Exhaust piping. 29.1123 Section 29.1123 Aeronautics...Powerplant Exhaust System § 29.1123 Exhaust piping. (a) Exhaust piping must be heat and corrosion resistant, and...

2012-01-01

333

14 CFR 27.1123 - Exhaust piping.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 2012-01-01 false Exhaust piping. 27.1123 Section 27.1123 Aeronautics...Powerplant Exhaust System § 27.1123 Exhaust piping. (a) Exhaust piping must be heat and corrosion resistant, and...

2012-01-01

334

14 CFR 29.1123 - Exhaust piping.  

Code of Federal Regulations, 2014 CFR

...2014-01-01 2014-01-01 false Exhaust piping. 29.1123 Section 29.1123 Aeronautics...Powerplant Exhaust System § 29.1123 Exhaust piping. (a) Exhaust piping must be heat and corrosion resistant, and...

2014-01-01

335

14 CFR 27.1123 - Exhaust piping.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Exhaust piping. 27.1123 Section 27.1123 Aeronautics...Powerplant Exhaust System § 27.1123 Exhaust piping. (a) Exhaust piping must be heat and corrosion resistant, and...

2011-01-01

336

14 CFR 27.1123 - Exhaust piping.  

Code of Federal Regulations, 2014 CFR

...2014-01-01 2014-01-01 false Exhaust piping. 27.1123 Section 27.1123 Aeronautics...Powerplant Exhaust System § 27.1123 Exhaust piping. (a) Exhaust piping must be heat and corrosion resistant, and...

2014-01-01

337

Simplified analysis of shrinkage in pipe to pipe butt welds  

Microsoft Academic Search

Generally some shrinkage is typical of butt welding of pipes. Shrinkage due to butt welding could be more pronounced and significant in thin wall stainless steel pipes because the thermal expansion coefficient is roughly one and half times that of carbon steel. An axisymmetric finite element evaluation of hoop shrinkage associated with circumferential butt welds in thin wall stainless steel

Chakrapani Basavaraju

2000-01-01

338

Large-bore pipe decontamination  

SciTech Connect

The decontamination and decommissioning (D and D) of 1200 buildings within the US Department of Energy-Office of Environmental Management (DOE-EM) Complex will require the disposition of miles of pipe. The disposition of large-bore pipe, in particular, presents difficulties in the area of decontamination and characterization. The pipe is potentially contaminated internally as well as externally. This situation requires a system capable of decontaminating and characterizing both the inside and outside of the pipe. Current decontamination and characterization systems are not designed for application to this geometry, making the direct disposal of piping systems necessary in many cases. The pipe often creates voids in the disposal cell, which requires the pipe to be cut in half or filled with a grout material. These methods are labor intensive and costly to perform on large volumes of pipe. Direct disposal does not take advantage of recycling, which could provide monetary dividends. To facilitate the decontamination and characterization of large-bore piping and thereby reduce the volume of piping required for disposal, a detailed analysis will be conducted to document the pipe remediation problem set; determine potential technologies to solve this remediation problem set; design and laboratory test potential decontamination and characterization technologies; fabricate a prototype system; provide a cost-benefit analysis of the proposed system; and transfer the technology to industry. This report summarizes the activities performed during fiscal year 1997 and describes the planned activities for fiscal year 1998. Accomplishments for FY97 include the development of the applicable and relevant and appropriate regulations, the screening of decontamination and characterization technologies, and the selection and initial design of the decontamination system.

Ebadian, M.A.

1998-01-01

339

Pipe Insulation Economies  

E-print Network

CALCIUM SILICATE ENTER 2 FOAMED URETHANE ENTER 3 MINERAL FIBER ENTER 4 FOAMED GLASS ENTER 5 PERLITE ENTER 6 WHAT IS YOUR INSULATION (1-6)? 2 WHAT IS THE WIND SPEED IN MILES-PER HOUR? 20 WHAT IS THE AMORTIZATION PERIOD IN YEARS? S WHAT... PRINT"WHAT IS THE OUTSIDE RADIUS OF THE PIPE";:INPUT R1:CLS 120 TM=(T1+T3)/2 130 PRINT"SELECT THE TYPE OF INSULATION FROM THIS L1ST: 1I 140 PRINT" FIBERGLASS ENTER 1" 150 PRINT" CALCIUM SILICATE ENTER 2" 160 PRINT" FOAMED URETHANE ENTER 3" 170...

Schilling, R. E.

340

Rehabilitating underground pipes  

SciTech Connect

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.

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

1995-06-05

341

Los Alamos National Laboratory corregated metal pipe saw facility preliminary safety analysis report. Volume I  

SciTech Connect

This Preliminary Safety Analysis Report addresses site assessment, facility design and construction, and design operation of the processing systems in the Corrugated Metal Pipe Saw Facility with respect to normal and abnormal conditions. Potential hazards are identified, credible accidents relative to the operation of the facility and the process systems are analyzed, and the consequences of postulated accidents are presented. The risk associated with normal operations, abnormal operations, and natural phenomena are analyzed. The accident analysis presented shows that the impact of the facility will be acceptable for all foreseeable normal and abnormal conditions of operation. Specifically, under normal conditions the facility will have impacts within the limits posted by applicable DOE guidelines, and in accident conditions the facility will similarly meet or exceed the requirements of all applicable standards. 16 figs., 6 tabs.

NONE

1990-09-19

342

Heat Pipes: An Industrial Application  

E-print Network

pipe exchangers, an industrial case history is presented. The case history involves a retrofit project which added heat pipes to five natural draft process heaters with a combined heat duty of 150 M Btu/hr. A heat recovery of 15 M Btu/hr has resulted...

Murray, F.

1984-01-01

343

Pipe crawler with stabilizing midsection  

DOEpatents

A pipe crawler having a midsection that provides the stability and flexibty to allow the pipe crawler to negotiate curved and uneven segments of piping while traveling through piping systems. The pipe crawler comprises a front leg assembly, a rear leg assembly, a midsection with a gimbal at each end for connecting the midsection to the front and rear leg assemblies in a flexible manner, and an air cylinder for changing the distance between the front and rear leg assemblies. The pipe crawler moves in "inch worm" fashion with the front and rear leg assemblies alternating between an extended and a retracted position as the air cylinder moves the retracted leg assembly forward. The midsection has a plurality of legs extending radially for holding the midsection within a maximum displacement from the piping axis so that the gimbals are not pivoted to extreme angles where they might lock up or seize. When the midsection is displaced sufficiently, its legs with wheels on each end engage the interior surface of the piping and prevent further displacement. Using two gimbals divides the angle between the planes defined by the front and rear leg assemblies which also helps to prevent excessive gimbal pivoting.

Zollinger, William T. (Martinez, GA); Treanor, Richard C. (Augusta, GA)

1994-01-01

344

Heat Pipe Blocks Return Flow  

NASA Technical Reports Server (NTRS)

Metal-foil reed valve in conventional slab-wick heat pipe limits heat flow to one direction only. With sink warmer than source, reed is forced closed and fluid returns to source side through annular transfer wick. When this occurs, wick slab on sink side of valve dries out and heat pipe ceases to conduct heat.

Eninger, J. E.

1982-01-01

345

Alternate high capacity heat pipe  

NASA Technical Reports Server (NTRS)

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.

Voss, F. E.

1986-01-01

346

Building a Copper Pipe "Xylophone."  

ERIC Educational Resources Information Center

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)

Lapp, David R.

2003-01-01

347

Vibration analysis methods for piping  

Microsoft Academic Search

Attention is given to flow vibrations in pipe flow induced by singularity points in the piping system. The types of pressure fluctuations induced by flow singularities are examined, including the intense wideband fluctuations immediately downstream of the singularity and the acoustic fluctuations encountered in the remainder of the circuit, and a theory of noise generation by unsteady flow in internal

R. J. Gibert

1981-01-01

348

Water flows from slotted pipes  

SciTech Connect

Results of experiments and analyses that determine jet flow distribution from slotted pipes of dimensions typical for OC-OTEC evaporators or condensers are described. For a pipe with a 6.3-cm inside diameter and 0.64-cm wide slot, the measured and predicted jet flow was low and nearly parallel to the pipe at the entrance, and high and perpendicular to the pipe only near the closed end. Slot lengths ranged from 1.5 m to 4.6 m, and inlet flow rates varied from 6 kg/s to 17 kg/s. Friction reduces the pressure in the entrance and intermediate portions of the pipe, while the rapidly decelerating flow produces high pressure recovery as it approaches the closed end. In the region of high flow next to the closed end, the ratio of slot area (slot length times width) to pipe cross-sectional area is less than two. To use a slotted pipe for generating falling jets in an OC-OTEC plant, the slot length should be 1 m or less (for a pipe with a 6.3-cm inside diameter and a 0.64-cm wide slot).

Olson, D.A.

1981-04-01

349

Hydrogen Piping Experience in Chevron  

E-print Network

) problem areas. Related industry work: American Petroleum Institute corrosion and materials work on high contamination presents many more problems, beyond the scope of this talk We will note a couple of specific, 2" hydrogen piping failure) 4 #12;5 Hydrogen piping experience largely from hydroprocessing plants

350

Pipe crawler with stabilizing midsection  

DOEpatents

A pipe crawler is described having a midsection that provides the stability and flexibility to allow the pipe crawler to negotiate curved and uneven segments of piping while traveling through piping systems. The pipe crawler comprises a front leg assembly, a rear leg assembly, a midsection with a gimbal at each end for connecting the midsection to the front and rear leg assemblies in a flexible manner, and an air cylinder for changing the distance between the front and rear leg assemblies. The pipe crawler moves in ''inch worm'' fashion with the front and rear leg assemblies alternating between an extended and a retracted position as the air cylinder moves the retracted leg assembly forward. The midsection has a plurality of legs extending radially for holding the midsection within a maximum displacement from the piping axis so that the gimbals are not pivoted to extreme angles where they might lock up or seize. When the midsection is displaced sufficiently, its legs with wheels on each end engage the interior surface of the piping and prevent further displacement. Using two gimbals divides the angle between the planes defined by the front and rear leg assemblies which also helps to prevent excessive gimbal pivoting. 5 figures.

Zollinger, W.T.; Treanor, R.C.

1994-12-27

351

Vapor spill pipe monitor  

DOEpatents

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.

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

1983-06-23

352

Spectral Formulation for the Solution of Full-Wave Scattering from a Conducting Wedge Tipped with a Corrugated Cylinder  

SciTech Connect

A spectral mode-matching technique is formulated to solve for the full-wave scattering of a corrugated cylinder-tipped wedge in the presence of an impressed electric or magnetic line source. Asymptotic approximations of large-order Bessel or Henkel functions for a fixed argument were introduced in order to overcome numerical difficulties in their regular series expansions. The corrugations on the conducting cylinder have the shape of annular sectors. The primary objective of this work is to investigate the impact of corrugations on the scattered field in the shadow region of the structure. An optimally designed corrugated cylinder placed at the tip of a conducting wedge can effectively suppress electromagnetic scattering in the shadow region. Obtained numerical results using the proposed approach prove the above concept. These results were validated against numerical data obtained using a nodal finite element method. The aim of this research is to utilize these corrugated tips in horn antenna design for the reduction of side-lobe level and the shaping of the respective E-plane radiation pattern.

Polycarpou, A. C. [Department of Electrical and Computer Engineering, University of Nicosia, 46, Makedonitissas Ave. P.O. Box 24005, 1700 Nicosia (Cyprus); Christou, M. A. [Department of Mathematics, University of Nicosia, 46, Makedonitissas Ave. P.O. Box 24005, 1700 Nicosia (Cyprus)

2011-11-29

353

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

NASA Astrophysics Data System (ADS)

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.

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

2014-04-01

354

Non-contact gears: I. Next-to-leading order contribution to lateral Casimir force between corrugated parallel plates  

E-print Network

We calculate the lateral Casimir force between corrugated parallel plates, described by $\\delta$-function potentials, interacting through a scalar field, using the multiple scattering formalism. The contributions to the Casimir energy due to uncorrugated parallel plates is treated as a background from the outset. We derive the leading- and next-to-leading-order contribution to the lateral Casimir force for the case when the corrugation amplitudes are small in comparison to corrugation wavelengths. We present explicit results in terms of finite integrals for the case of the Dirichlet limit, and exact results for the weak-coupling limit, for the leading- and next-to-leading-orders. The correction due to the next-to-leading contribution is significant. In the weak coupling limit we calculate the lateral Casimir force exactly in terms of a single integral which we evaluate numerically. Exact results for the case of the weak limit allows us to estimate the error in the perturbative results. We show that the error in the lateral Casimir force, in the weak coupling limit, when the next-to-leading order contribution is included is remarkably low when the corrugation amplitudes are small in comparison to corrugation wavelengths. We expect similar conclusions to hold for the Dirichlet case. The analogous calculation for the electromagnetic case should reduce the theoretical error sufficiently for comparison with the experiments.

Ines Cavero-Pelaez; Kimball A. Milton; Prachi Parashar; K. V. Shajesh

2008-07-03

355

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

DOEpatents

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.

Fischer, William H. (Pittsburgh, PA)

1984-01-01

356

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

SciTech Connect

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.

Fischer, W.H.

1984-04-24

357

Flexible ultrasonic pipe inspection apparatus  

DOEpatents

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.

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

1998-01-01

358

Prometheus Hot Leg Piping Concept  

NASA Astrophysics Data System (ADS)

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.

Gribik, Anastasia M.; DiLorenzo, Peter A.

2007-01-01

359

Vibration analysis methods for piping  

NASA Astrophysics Data System (ADS)

Attention is given to flow vibrations in pipe flow induced by singularity points in the piping system. The types of pressure fluctuations induced by flow singularities are examined, including the intense wideband fluctuations immediately downstream of the singularity and the acoustic fluctuations encountered in the remainder of the circuit, and a theory of noise generation by unsteady flow in internal acoustics is developed. The response of the piping systems to the pressure fluctuations thus generated is considered, and the calculation of the modal characteristics of piping containing a dense fluid in order to obtain the system transfer function is discussed. The TEDEL program, which calculates the vibratory response of a structure composed of straight and curved pipes with variable mechanical characteristics forming a three-dimensional network by a finite element method, is then presented, and calculations of fluid-structural coupling in tubular networks are illustrated.

Gibert, R. J.

1981-09-01

360

Technology for concrete pipe manipulator  

NASA Astrophysics Data System (ADS)

The pipe manipulator is a developing mechatronic system to enhance productivity and protects workers from cave-ins in the trench while excavating and laying pipe. The pipe manipulator is for installing concrete pipe into the trench. It is an optical-electro-mechanical system. The mechanism is make up of two parts, the upside and underside. The upside is for lifting the equipment by backhoe and rotating the underside mechanism. It includes rigidity lift beams, holding pad, four-bar linkages, hydraulic cylinder, rotating support, and rotating mechanism. Holding pad will press the bucket back to keep the bucket hooking the pipe man safely and stably. The underside mechanism is for lifting, holding and adjusting the pipe section's stance. The underside mechanism includes support trolley, and lift fork. The support trolley is driven by hydraulic cylinder for moving the fork forward or backward while laying a pipe into trench. The fork is with a self-lock mechanism for preventing the pipe from slide out of the prongs. A new photoelectric locating system is developed for auto-measuring the installing pipe section's stance within the work area. The laser target has been developed as a key part in the photoelectric locating systems. The photoelectric target is a rotating polar coordinate. Photodiodes are used for making the polar radius. There is an angular displacement sensor sitting on the heart-axis of the target for measuring angle of the target rotating. The pipe manipulator can be located by the system, and the locating methods have been presented at last of the paper.

Li, Bin; Wang, Dan; Lin, Renzhi

2009-12-01

361

Technology for concrete pipe manipulator  

NASA Astrophysics Data System (ADS)

The pipe manipulator is a developing mechatronic system to enhance productivity and protects workers from cave-ins in the trench while excavating and laying pipe. The pipe manipulator is for installing concrete pipe into the trench. It is an optical-electro-mechanical system. The mechanism is make up of two parts, the upside and underside. The upside is for lifting the equipment by backhoe and rotating the underside mechanism. It includes rigidity lift beams, holding pad, four-bar linkages, hydraulic cylinder, rotating support, and rotating mechanism. Holding pad will press the bucket back to keep the bucket hooking the pipe man safely and stably. The underside mechanism is for lifting, holding and adjusting the pipe section's stance. The underside mechanism includes support trolley, and lift fork. The support trolley is driven by hydraulic cylinder for moving the fork forward or backward while laying a pipe into trench. The fork is with a self-lock mechanism for preventing the pipe from slide out of the prongs. A new photoelectric locating system is developed for auto-measuring the installing pipe section's stance within the work area. The laser target has been developed as a key part in the photoelectric locating systems. The photoelectric target is a rotating polar coordinate. Photodiodes are used for making the polar radius. There is an angular displacement sensor sitting on the heart-axis of the target for measuring angle of the target rotating. The pipe manipulator can be located by the system, and the locating methods have been presented at last of the paper.

Li, Bin; Wang, Dan; Lin, Renzhi

2010-01-01

362

Disrupting the wall accumulation of human sperm cells by artificial corrugation  

E-print Network

Many self-propelled microorganisms are attracted to surfaces. This makes their dynamics in restricted geometries very different from that observed in the bulk. Swimming along walls is beneficial for directing and sorting cells, but may be detrimental if homogeneous populations are desired, such as in counting microchambers. In this work, we characterize the motion of human sperm cells $\\sim$60$\\mu$m long, strongly confined to $\\sim$20$\\mu$m shallow chambers. We investigate the nature of the cell trajectories between the confining surfaces and their accumulation near the borders. Observed cell trajectories are composed of a succession of quasi-circular and quasi-linear segments. This suggests that the cells follow a path of intermittent trappings near the top and bottom surfaces separated by stretches of quasi-free motion in between the two surfaces. We show that the introduction of artificial petal-shaped corrugation in the lateral boundaries limits the accumulation near the borders and contributes to increase the concentration in the chamber interior. The steady state limit is achieved over times of the order of minutes, which agrees well with a theoretical estimate based on the assumption that the cell mean-square displacement is largely due to the quasi-linear segments. Pure quasi-circular trajectories would require several hours to stabilize. Our predictions also indicate that stabilization proceeds 2.5 times faster in the corrugated chambers than in the non-corrugated ones, which is another practical reason to prefer the former for microfluidic applications in biomedicine.

H. A. Guidobaldi; Y. Jeyaram; C. A. Condat; M. Oviedo; I. Berdakin; V. V. Moshchalkov; L. C. Giojalas; A. V. Silhanek; V. I. Marconi

2015-01-07

363

Analysis of Bonded Joints Between the Facesheet and Flange of Corrugated Composite Panels  

NASA Technical Reports Server (NTRS)

This paper outlines a method for the stress analysis of bonded composite corrugated panel facesheet to flange joints. The method relies on the existing HyperSizer Joints software, which analyzes the bonded joint, along with a beam analogy model that provides the necessary boundary loading conditions to the joint analysis. The method is capable of predicting the full multiaxial stress and strain fields within the flange to facesheet joint and thus can determine ply-level margins and evaluate delamination. Results comparing the method to NASTRAN finite element model stress fields are provided illustrating the accuracy of the method.

Yarrington, Phillip W.; Collier, Craig S.; Bednarcyk, Brett A.

2008-01-01

364

High performance WR-1.5 corrugated horn based on stacked rings  

NASA Astrophysics Data System (ADS)

We present the development and characterisation of a high frequency (500 - 750 GHz) corrugated horn based on stacked rings. A previous horn design, based on a Winston profile, has been adapted for the purpose of this manufacturing process without noticeable RF degradation. A subset of experimental results obtained using a vector network analyser are presented and compared to the predicted performance. These first results demonstrate that this technology is suitable for most commercial applications and also astronomical receivers in need of horn arrays at high frequencies.

Maffei, Bruno; von Bieren, Arndt; de Rijk, Emile; Ansermet, Jean-Philippe; Pisano, Giampaolo; Legg, Stephen; Macor, Alessandro

2014-07-01

365

Distributed-feedback Terahertz Quantum-cascade Lasers with Laterally Corrugated Metal Waveguides  

NASA Technical Reports Server (NTRS)

We report the demonstration of distributed-feedback terahertz quantum-cascade lasers based on a first-order grating fabricated via a lateral corrugation in a double-sided metal ridge waveguide. The phase of the facet reflection was precisely set by lithographically defined facets by dry etching. Single-mode emission was observed at low to moderate injection currents, although multimode emission was observed far beyond threshold owing to spatial hole burning. Finite-element simulations were used to calculate the modal and threshold characteristics for these devices, with results in good agreement with experiments.

Williams, Benjamin S.; Kumar, Sushil; Hu, Qing; Reno, John L.

2005-01-01

366

Eddy Current System for Detection of Cracking Beneath Braiding in Corrugated Metal Hose  

NASA Technical Reports Server (NTRS)

In this paper an eddy current system for the detection of partially-through-the-thickness cracks in corrugated metal hose is presented. Design criteria based upon the geometry and conductivity of the part are developed and applied to the fabrication of a prototype inspection system. Experimental data are used to highlight the capabilities of the system and an image processing technique is presented to improve flaw detection capabilities. A case study for detection of cracking damage in a space shuttle radiator retract flex hoses is also presented.

Wincheski, Buzz; Simpson, John; Hall, George

2008-01-01

367

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

E-print Network

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.

Ben-Aryeh, Y

2015-01-01

368

Shear Lag in Corrugated Sheets Used for the Chord Member of a Box Beam  

NASA Technical Reports Server (NTRS)

The problem of the distribution of normal stress across a wide corrugated sheet used as the chord of a box-beam-like structure is investigated theoretically and experimentally. Expressions are developed giving the stress distribution in beams, symmetrical or unsymmetrical, about a plane passed spanwise through the center of the sheet. The experiments were arranged to insure bending without torsion and surveys of the normal stresses were made by means of mechanical and electrical strain gages. The experimental data showed very good agreement with the new b of the theoretical curves, especially at the highly stressed sections, for both the symmetrical and unsymmetrical beams. Several suggestions for future research are included.

Newell, Joseph S; Reissner, Eric

1941-01-01

369

Importance of anisotropy on design of compression-loaded composite corrugated panels  

NASA Technical Reports Server (NTRS)

An investigation is conducted of the importance of anisotropic terms in the design of composite corrugated panels, for a range of axial compressive load intensities. The two panel configurations treated were panels with tailored laminates and panels with a continuous laminate; both are of interest to aircraft designers and prone to anisotropic effects which are of as-yet undetermined extent. The importance of the anisotropic terms is measured by the difference between the design load and the buckling load obtained from the ultimate structural analysis.

Gurdal, Zafer; Young, Richard D.

1990-01-01

370

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

NASA Technical Reports Server (NTRS)

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.

Jegley, Dawn C.

1993-01-01

371

Effects of metallic absorption and the corrugated layer on the optical extraction efficiency of organic light-emitting diodes  

E-print Network

The absorption of a metallic cathode in OLEDs is analyzed by using FDTD calculation. As the light propagates parallel to the layer, the intensity of Ez polarization decreases rapidly. The intensity at 2.0 um from the dipole is less than a quarter of that at 0.5 um. The strong absorption by a cathode can be a critical factor when considering the increase of optical extraction by means of bending the optical layers. The calculation indicates that the corrugation of layers helps the guided light escape the guiding layer, but also increases the absorption into a metallic cathode. The final optical output power of the corrugated OLED can be smaller than that of the flat OLED. On the contrary, the corrugated structure with a non-absorptive cathode increases the optical extraction by nearly two times.

Lee, Baek-Woon

2011-01-01

372

Heat pipe technology: A bibliography with abstracts  

NASA Technical Reports Server (NTRS)

A cumulative bibliography on heat pipe research and development projects is presented. The subjects discussed are: (1) general information, (2) heat pipe applications, (3) heat pipe theory, (4) design and fabrication, (5) testing and operation, (6) subject and author index, and (7) heat pipe related patents.

1971-01-01

373

Decontaminating Aluminum/Ammonia Heat Pipes  

NASA Technical Reports Server (NTRS)

Internal gas slugs reduced or eliminated. Manufacturing method increases efficiency of aluminum heat pipes in which ammonia is working fluid by insuring pipe filled with nearly pure charge of ammonia. In new process heat pipe initially closed with stainless-steel valve instead of weld so pipe put through several cycles of filling, purging, and accelerated aging.

Jones, J. A.

1985-01-01

374

Determination of Secondary Encasement Pipe Design Pressure  

SciTech Connect

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.

TEDESCHI, A.R.

2000-10-26

375

Page 1 of 1 Pipe School  

E-print Network

­ Rigid and Flexible Pipes: A comparison of rigid (concrete, clay, etc.) and flexible (steel, HDPE, PVC own) 1:00 PM Design and Construction Considerations for PVC Pipe: Everything you need to know about PVC pipe and its applications. John Houle, P.E., Uni-Bell PVC Pipe Association 1:45 Design

Huang, Haiying

376

46 CFR 108.447 - Piping.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 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...

2013-10-01

377

Structural Assessment of Small Bore Feeder Piping  

E-print Network

BACKGROUND 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 PIPES AND VALIDATE COMPUTATIONAL METHODS COMPARED TO FULL SCALE TESTS TO FAILURE. THE CLIENT CANDU

378

46 CFR 108.447 - Piping.  

Code of Federal Regulations, 2012 CFR

...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...

2012-10-01

379

Page 1 of 1 Pipe School  

E-print Network

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

Huang, Haiying

380

46 CFR 108.447 - Piping.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 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...

2011-10-01

381

Hg supply piping simulation Stony Brook University  

E-print Network

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

McDonald, Kirk

382

46 CFR 108.447 - Piping.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 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...

2014-10-01

383

46 CFR 56.10-5 - Pipe.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 false Pipe. 56.10-5 Section...CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND...Components § 56.10-5 Pipe. (a) General...2) Copper and brass pipe for air may be used in...accordance with the allowable stresses found from table...

2014-10-01

384

Grey Cast Iron Water Pipe Metallurgy  

Microsoft Academic Search

The results of a metallographic study of grey cast iron water pipes are reported. These pipes had been installed between 1885 and 1973 in eight different water systems. Each pipe had been extracted during scheduled maintenance or failure repairs to provide data for a larger study to produce a methodology for determining the residual life of grey cast iron pipes.

J. M. Makar; B. Rajani

385

Heat pipe technology: A biblography with abstracts  

NASA Technical Reports Server (NTRS)

A bibliography of heat pipe research and development projects conducted during April through June 1972, is presented. The subjects discussed are: (1) general information, (2) heat pipe applications, (3) heat pipe theory, (4) design and fabrication, (5) test and operation, (6) subject and author index, and (7) heat pipe related patents.

1972-01-01

386

Heat pipe experiment on SPAS 01  

NASA Astrophysics Data System (ADS)

The second flight of Challenger carried a heat pipe experiment, designed to measure the performance of constant conductance heat pipe diodes over a period of 16 hr. The experiment platform and the flight results on variable conductance heat pipe housekeeping radiators, including the temperature distribution at these heat pipe versus experiment time are presented. All equipment is shown to be space qualified.

Kock, H.; Kreeb, H.; Savage, C.

1986-08-01

387

Abrasion protection in process piping  

SciTech Connect

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.

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

1996-07-01

388

Heat pipe transient response approximation.  

SciTech Connect

A simple and concise routine that approximates the response of an alkali metal heat pipe to changes in evaporator heat transfer rate is described. This analytically based routine is compared with data from a cylindrical heat pipe with a crescent-annular wick that undergoes gradual (quasi-steady) transitions through the viscous and condenser boundary heat transfer limits. The sonic heat transfer limit can also be incorporated into this routine for heat pipes with more closely coupled condensers. The advantages and obvious limitations of this approach are discussed. For reference, a source code listing for the approximation appears at the end of this paper.

Reid, R. S. (Robert Stowers)

2001-01-01

389

Heat pipe life and processing study  

NASA Technical Reports Server (NTRS)

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.

Antoniuk, D.; Luedke, E. E.

1979-01-01

390

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

NASA Technical Reports Server (NTRS)

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.

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

2014-01-01

391

Finite element modelling of surface acoustic wave device based corrugated microdiaphragms  

NASA Astrophysics Data System (ADS)

This paper presents modelling and analysis of microdiaphragms that are designed for implantable micropump applications. Microdiaphragms are considered to be a major component of micropumps. A securely operated, electrostatically actuated, fully passive micropump is designed using a novel method, which is based on surface acoustic wave (SAW) devices and wireless transcutaneous radio frequency (RF) communication. The device is capable of extracting the required power from the RF signal itself, like RFID (ID: identification device) tags; hence the need of a battery and active electronics is negated. Moreover, a SAW correlator is used for secure interrogation of the device. As a result, the device responds only to a unique RF signal, which has the same code as was implanted in the SAW correlator. Finite element analysis (FEA) based on code from ANSYS Inc. is carried out to model the microdiaphragm, and a Rayleigh-Ritz method based analytical model is developed to investigate the validity of the FEA results. During the FEA, a three-dimensional model of the diaphragm is developed and various kinds of corrugation profiles are considered for enhancing the device performance. A coupled-field analysis is carried out to model the electrostatics-solid interaction between the corrugated microdiaphragm and the SAW device. In modelling microdiaphragms, selection of appropriate material properties and element types, application of accurate constraints, and selection of suitable mesh parameters are carefully considered.

Dissanayake, Don W.; Al-Sarawi, Said; Lu, Tien-Fu; Abbott, Derek

2009-09-01

392

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

NASA Astrophysics Data System (ADS)

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.

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

2015-01-01

393

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

SciTech Connect

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.

Dumortier, Pierre; Louche, Fabrice; Messiaen, André; Vervier, Michel [LPP-ERM/KMS, EURATOM-Belgian State Association, TEC partner, B-1000 Brussels (Belgium)

2014-02-12

394

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

DOE PAGESBeta

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.

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

2015-01-30

395

Atomic-scale friction modulated by potential corrugation in multi-layered graphene materials  

NASA Astrophysics Data System (ADS)

Friction is an important issue that has to be carefully treated for the fabrication of graphene-based nano-scale devices. So far, the friction mechanism of graphene materials on the atomic scale has not yet been clearly presented. Here, first-principles calculations were employed to unveil the friction behaviors and their atomic-scale mechanism. We found that potential corrugations on sliding surfaces dominate the friction force and the friction anisotropy of graphene materials. Higher friction forces correspond to larger corrugations of potential energy, which are tuned by the number of graphene layers. The friction anisotropy is determined by the regular distributions of potential energy. The sliding along a fold-line path (hollow-atop-hollow) has a relatively small potential energy barrier. Thus, the linear sliding observed in macroscopic friction experiments may probably be attributed to the fold-line sliding mode on the atomic scale. These findings can also be extended to other layer-structure materials, such as molybdenum disulfide (MoS2) and graphene-like BN sheets.

Zhuang, Chunqiang; Liu, Lei

2015-03-01

396

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

SciTech Connect

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.

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

2008-10-30

397

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

NASA Technical Reports Server (NTRS)

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.

Johnson, R., Jr.

1978-01-01

398

Experimental demonstration of a high-power slow wave electron cyclotron maser utilizing corrugated metal structure  

SciTech Connect

High-power microwave (HPM) sources based on electron cyclotron resonance (ECR) such as gyrotrons are fast wave devices and velocity component of electron beam perpendicular to guiding magnetic field is the origin of HPM. HPM sources based on Cherenkove mechanism are slow wave devices and can be driven by a beam without initial perpendicular velocity. The authors present here the experimental result that seems to be the first demonstration of high-power slow wave electron cyclotron maser (ECM) consisting of a large diameter sinusoidally corrugated metal waveguide driven by a beam with predominant parallel velocity. The designed size parameters of slow wave structure (SWS) are as follows: average radius 30 mm, corrugation pitch 3.4 mm, its amplitude h = 1.7 mm and total length 238 mm. They use an annular beam with radius 26.3 mm, energy 55 keV, current 200 A in their experiment. Expected Cherenkov oscillation frequency of TM01 mode is 20 GHz. The observed high-power microwaves can be quantitatively explained by a backward wave oscillation with Cherenkov mechanism enhanced by positive feedback of anomalous Doppler slow cyclotron wave. In conclusion, the slow wave ECM presented here will be a competitive candidate against gyrotrons for generating multi-MW millimeter microwaves available in fusion plasma research.

Minami, K.; Ogura, K.; Kurashina, K; Kim, W. [Niigata Univ. (Japan). Dept. of Electrical Engineering; Watanabe, Tsuguhiro [National Inst. for Fusion Research, Nagoya (Japan); Carmel, Y.; Destler, W.W.; Granatstein, V.L. [Univ. of Maryland, College Park, MD (United States). Inst. for Plasma Research

1994-12-31

399

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

PubMed Central

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

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

2014-01-01

400

Heat Pipe Applications in Sorption Refrigerators  

Microsoft Academic Search

\\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].

L. L. Vasiliev; A. G. Kulakov

401

Intermediate Temperature Water Heat Pipe Tests  

NASA Technical Reports Server (NTRS)

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.

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

2005-01-01

402

Intermediate Temperature Water Heat Pipe Tests  

NASA Technical Reports Server (NTRS)

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.

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

2004-01-01

403

Method for casting polyethylene pipe  

NASA Technical Reports Server (NTRS)

Short lengths of 7-cm ID polyethylene pipe are cast in a mold which has a core made of room-temperature-vulcanizable (RTV) silicone. Core expands during casting and shrinks on cooling to allow for contraction of the polyethylene.

Elam, R. M., Jr.

1973-01-01

404

Heat pipe radiators for space  

NASA Technical Reports Server (NTRS)

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 freeze-thaw thermal vacuum tests conducted on the feasibility VCHP was included. In addition, the results of ambient tests made on the feasibility fluid header are presented, including a comparison with analytical results. A thermal model of a fluid header heat pipe radiator was constructed and a computer program written. The program was used to make a comparison of the VCHP and fluid-header concepts for both single and multiple panel applications. The computer program was also employed for a parametric study, including optimum feeder heat pipe spacing, of the prototype fluid header.

Sellers, J. P.

1976-01-01

405

Light pipes for LED measurements  

NASA Technical Reports Server (NTRS)

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.

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

1976-01-01

406

Loop Heat Pipe Startup Behaviors  

NASA Technical Reports Server (NTRS)

A loop heat pipe must start successfully before it can commence its service. The start-up transient represents one of the most complex phenomena in the loop heat pipe operation. This paper discusses various aspects of loop heat pipe start-up behaviors. Topics include the four start-up scenarios, the initial fluid distribution between the evaporator and reservoir that determines the start-up scenario, factors that affect the fluid distribution between the evaporator and reservoir, difficulties encountered during the low power start-up, and methods to enhance the start-up success. Also addressed are the thermodynamic constraint between the evaporator and reservoir in the loop heat pipe operation, the superheat requirement for nucleate boiling, pressure spike and pressure surge during the start-up transient, and repeated cycles of loop start-up andshutdown under certain conditions.

Ku, Jentung

2014-01-01

407

Mapping Temperatures On Heat Pipes  

NASA Technical Reports Server (NTRS)

Paints containing thermochromic liquid crystals (TLC's) used to map temperatures on heat pipes and thermosyphons. Color of thermally sensitive TLC coat changes reversibly upon heating or cooling. Each distinct color indicates particular temperature. Transient and steady-state isotherms become visible as colored bands. Positions and movements of bands yield information about startup transients, steady-state operation, cooler regions containing noncondensible gas, and other phenomena relevant to performance of heat pipe.

Gunnerson, Fred S.; Thorncroft, Glen E.

1993-01-01

408

Heat Pipe Thermal Conditioning Panel  

NASA Technical Reports Server (NTRS)

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.

Saaski, E. W.

1973-01-01

409

Heat pipe cooled power magnetics  

NASA Technical Reports Server (NTRS)

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.

Chester, M. S.

1979-01-01

410

Automated internal pipe cutting device  

DOEpatents

The invention is a remotely controlled internal pipe cutting device primarily used for cutting pipes where the outside of the pipe is inaccessible at the line where the cut is to be made. The device includes an axial ram within a rotational cylinder which is enclosed in a housing. The housing is adapted for attachment to an open end of the pipe and for supporting the ram and cylinder in cantilever fashion within the pipe. A radially movable cutter, preferably a plasma arc torch, is attached to the distal end of the ram. A drive mechanism, containing motors and mechanical hardware for operating the ram and cylinder, is attached to the proximal end of the housing. The ram and cylinder provide for moving the cutter axially and circumferentially, and a cable assembly attached to a remote motor provide for the movement of the cutter radially, within the pipe. The control system can be adjusted and operated remotely to control the position and movement of the cutter to obtain the desired cut. The control system can also provide automatic standoff control for a plasma arc torch.

Godlewski, William J. (Clifton Park, NY); Haffke, Gary S. (Ballston Spa, NY); Purvis, Dale (Amsterdam, NY); Bashar, Ronald W. (Oakdale, CT); Jones, Stewart D. (Mechanicville, NY); Moretti, Jr., Henry (Cranston, RI); Pimentel, James (Warwick, RI)

2003-01-21

411

Light Pipe Energy Savings Calculator  

NASA Astrophysics Data System (ADS)

Dependence on fossil fuels is unsustainable and therefore a shift to renewable energy sources such as sunlight is required. Light pipes provide a way to utilize sunlight for interior lighting, and can reduce the need for fossil fuel-generated electrical energy. Because consumers considering light pipe installation may be more strongly motivated by cost considerations than by sustainability arguments, an easy means to examine the corresponding costs and benefits is needed to facilitate informed decision-making. The purpose of this American Physical Society Physics and Society Fellowship project is to create a Web-based calculator to allow users to quantify the possible cost savings for their specific light pipe application. Initial calculations show that the illumination provided by light pipes can replace electric light use during the day, and in many cases can supply greater illumination levels than those typically given by electric lighting. While the installation cost of a light pipe is significantly greater than the avoided cost of electricity over the lifetime of the light pipe at current prices, savings may be realized if electricity prices increase.

Owens, Erin; Behringer, Ernest R.

2009-04-01

412

Organ pipe resonance induced vibration in piping system  

SciTech Connect

Acoustic-induced vibration is a fluid-structure interaction phenomenon. The feedback mechanism between the acoustic pressure pulsation and the structure movements determines the excited acoustic modes which, in turn, amplify the structure response when confidence frequency and mode shape matching occurs. The acoustic modes are not determined from the acoustic boundary conditions alone, structure feedback is as responsible for determining the acoustic modes and shaping the resulting forcing functions. Acoustic-induced piping vibration, when excited, does not attenuate much with distance. Pressure pulsation can be transmitted throughout the piping system and its branch connections. It is this property that makes vibration monitoring difficult, because vibration can surface at locations far away from the acoustic source when resonance occurs. For a large piping system with interconnected branches, the monitoring task can be formidable, particularly when there is no indication what the real source is. In organ pipe resonance induced vibration, the initiating acoustic source may be inconspicuous or unavoidable during operation. In these situations, the forcing function approach can offer an optimal tool for vibration assessment. The forcing function approach was used in the evaluation of a standby steam piping vibration problem. Monitoring locations and instrument specifications were determined from the acoustic eigenfunction profiles. Measured data confirmed the presence of coherent vibrations in the large bore piping. The developed forcing function permits design evaluation of the piping system, which leads to remedial actions and enables fatigue life determination, thus providing confidence to system operation. The forcing function approach is shown to be useful in finding potential vibration area and verifying the integrity of weak structure links. Application is to steam lines at BWR plants.

Wang, T.

1996-12-01

413

Well pipe float valve  

SciTech Connect

This patent describes a drill pipe float assembly comprising an elongated cylindrical cage having upper and lower rings joined by diametrically opposite vertical wall members. The upper ring has a downwardly facing valve seat on its inner perimeter. The assembly includes a valve stem guide member supported by the lower ring including a central vertical bearing sleeve slidable guiding the depending end portion of a valve stem. The valve stem has a valve on its upper end including an elastomer seal seating and unseating on the valve seat in response to the direction of fluid flow through the ring members, cylindrical spring retainer on the valve stem in contact with the valve seal, and a helical spring surrounding the valve stem and biasing the valve toward its seat, the improvement comprising: means secured to the respective confronting end surfaces of the spring retainer and the valve stem guide sleeve for interdigitated engagement in response to fluid flow in one direction through the float assembly.

Taylor, J.S.

1986-11-18

414

Piping inspection round robin  

SciTech Connect

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.

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

1996-04-01

415

Leaks in pipe networks  

USGS Publications Warehouse

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.

Pudar, Ranko S.; Liggett, James A.

1992-01-01

416

A negativity bias for ambiguous facial-expression valence during childhood: converging evidence from behavior and facial corrugator muscle responses.  

PubMed

Interpretations of facial expressions with ambiguous valence, such as surprised (which can be perceived as having positive or negative valence), reveal individual differences in positivity-negativity biases. Negative interpretations are first and fast, but this initial negativity default can be overridden by regulatory control processes that result in positive interpretations. We tested the initial negativity hypothesis by examining positivity-negativity biases during development. We hypothesized that during childhood, the default negativity mode would be more evident than in adulthood and, as a group, children would show a negativity bias when processing ambiguous facial expressions. We examined ratings of two ambiguous expressions, surprised and neutral expressions, from childhood through adolescence and recorded facial corrugator muscle activity, a physiological index of negative appraisals. Surprised faces were rated as conveying clear negative affect by younger participants as indexed by fast RTs and negative ratings, and corrugator data showed a corresponding increase in activity to surprised faces. By adolescence, positive ratings of surprised faces became more frequent and RTs slowed, suggesting that surprised faces were perceived as having more ambiguous meaning. Accordingly, corrugator activity also decreased during adolescence. Neutral faces also produced negative ratings by children, but were also rated as conveying negative affect by older participants. Accordingly, neutral faces also elicited high corrugator activity that was similar to that elicited by negative expressions. These data show that early in life, ambiguous facial expressions are perceived as conveying negative meaning, adding support for an initial-negativity hypothesis. PMID:22906084

Tottenham, Nim; Phuong, Jessica; Flannery, Jessica; Gabard-Durnam, Laurel; Goff, Bonnie

2013-02-01

417

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

E-print Network

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

Wadley, Haydn

418

Atomic scale study of corrugating and anticorrugating states on the bare Si(1?0?0) surface  

NASA Astrophysics Data System (ADS)

In this article, we study the origin of the corrugating and anticorrugating states through the electronic properties of the Si(1?0?0) surface via a low-temperature (9 K) scanning tunneling microscope (STM). Our study is based on the analysis of the STM topographies corrugation variations when related to the shift of the local density of states (LDOS) maximum in the [1 \\bar{{1}} 0] direction. Our experimental results are correlated with numerical simulations using the density-functional theory with hybrid Heyd–Scuseria–Ernzerhof (HSE06) functional to simulate the STM topographies, the projected density of states variations at different depths in the silicon surface as well as the three dimensional partial charge density distributions in real-space. This work reveals that the Si(1?0?0) surface exhibits two anticorrugating states at +0.8 and +2.8 V that are associated with a phase shift of the LDOS maximum in the unoccupied states STM topographies. By comparing the calculated data with our experimental results, we have been able to identify the link between the variations of the STM topographies corrugation and the shift of the LDOS maximum observed experimentally. Each surface voltage at which the STM topographies corrugation drops is defined as anticorrugating states. In addition, we have evidenced a sharp jump in the tunnel current when the second LDOS maximum shift is probed, whose origin is discussed and associated with the presence of Van Hove singularities.

Yengui, Mayssa; Pinto, Henry P.; Leszczynski, Jerzy; Riedel, Damien

2015-02-01

419

IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 53, NO. 6, JUNE 2005 1863 Corrugated Waveguide and Directional Coupler for  

E-print Network

ideally couples to a free-space Gaussian beam, which is optimum for achieving the Manuscript received MayIEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 53, NO. 6, JUNE 2005 1863 Corrugated, M. K. Hornstein, and R. J. Temkin are with the Plasma Science and Fusion Center, Massachusetts

Griffin, Robert G.

420

A Dual Resonant Microstrip Antenna for UHF RFID in the Cold Chain Using Corrugated Fiberboard as a Substrate  

E-print Network

and thus will help reducing food borne illness. Passive UHF RFID has been widely accepted to be a technology capable of increasing supply chain efficiency. Passive UHF RFID tags designed for supply chain application are tuned to work well on corrugated...

Sivakumar, Mutharasu

2008-02-01

421

NEP heat pipe radiators. [Nuclear Electric Propulsion  

NASA Technical Reports Server (NTRS)

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.

Ernst, D. M.

1979-01-01

422

Growth of InP directly on Si by corrugated epitaxial lateral overgrowth  

NASA Astrophysics Data System (ADS)

In an attempt to achieve an InP–Si heterointerface, a new and generic method, the corrugated epitaxial lateral overgrowth (CELOG) technique in a hydride vapor phase epitaxy reactor, was studied. An InP seed layer on Si (0?0?1) was patterned into closely spaced etched mesa stripes, revealing the Si surface in between them. The surface with the mesa stripes resembles a corrugated surface. The top and sidewalls of the mesa stripes were then covered by a SiO2 mask after which the line openings on top of the mesa stripes were patterned. Growth of InP was performed on this corrugated surface. It is shown that growth of InP emerges selectively from the openings and not on the exposed silicon surface, but gradually spreads laterally to create a direct interface with the silicon, hence the name CELOG. We study the growth behavior using growth parameters. The lateral growth is bounded by high index boundary planes of {3?3?1} and {2?1?1}. The atomic arrangement of these planes, crystallographic orientation dependent dopant incorporation and gas phase supersaturation are shown to affect the extent of lateral growth. A lateral to vertical growth rate ratio as large as 3.6 is achieved. X-ray diffraction studies confirm substantial crystalline quality improvement of the CELOG InP compared to the InP seed layer. Transmission electron microscopy studies reveal the formation of a direct InP–Si heterointerface by CELOG without threading dislocations. While CELOG is shown to avoid dislocations that could arise due to the large lattice mismatch (8%) between InP and Si, staking faults could be seen in the layer. These are probably created by the surface roughness of the Si surface or SiO2 mask which in turn would have been a consequence of the initial process treatments. The direct InP–Si heterointerface can find applications in high efficiency and cost-effective Si based III–V semiconductor multijunction solar cells and optoelectronics integration.

Metaferia, Wondwosen; Kataria, Himanshu; Sun, Yan-Ting; Lourdudoss, Sebastian

2015-02-01

423

Electrohydrodynamically augmented micro heat pipes  

NASA Astrophysics Data System (ADS)

For high power density dissipation, micro heat pipes and micro grooves have demonstrated much promise. Several experimental investigations were conducted to evaluate the potential benefits of electrohydrodynamic (EHD) forces on the operation of micro heat pipes. In these experiments, electric fields were used to orient and guide the flow of the dielectric liquid within the micro heat pipes from the condenser to the evaporator. The first series of experiments indicate that the heat transport capability of the EHD micro heat pipes is increased by up to 6 times of that of conventional ones. Simultaneously, a theoretical model was developed to predict the maximum heat transport capability for various electric field intensities and micro heat pipe geometries. The analytical model agrees well with the experimental results. The model shows that large pore sizes are optimal from a heat transport capacity perspective. Finally, a critical assessment of the experimental results suggest an alternative design capable of achieving as much as a 240 times improvement in the heat transport capacity in comparison to traditional micro heat pipes. Another means to augment the heat transport capacity of micro heat pipes is to employ an ion-drag pumping. An analytical model is developed to evaluate the maximum heat transport capacity as a function of the applied electric field. The predictions indicate that ion drag pumping can achieve a four times increase in heat transport capacity under the application of an electric field relative to what would exist in the absence of a field. A transient analytical model was developed to permit variation of the electric field with applied thermal load. A proportional-integral-derivative controller was used to simulate active temperature control. The feasibility of achieving active temperature control was demonstrated experimentally. Finally, a simpler EHD enhanced micro groove model was constructed and tested. A pair of electrodes was used as a liquid artery to convey the working liquid from the condenser to the evaporator. A six times increase of the heat transport capability was obtained.

Yu, Zhiquan

2001-12-01

424

Magnetic refrigeration apparatus with heat pipes  

DOEpatents

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 or 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.

Barclay, J.A.; Prenger, F.C. Jr.

1985-10-25

425

Surface Plasmon-Polariton Mediated Red Emission from Organic Light-Emitting Devices Based on Metallic Electrodes Integrated with Dual-Periodic Corrugation  

NASA Astrophysics Data System (ADS)

We demonstrate an effective approach to realize excitation and outcoupling of the SPP modes associated with both cathode/organic and anode/organic interfaces in OLEDs by integrating dual-periodic corrugation. The dual-periodic corrugation consists of two set gratings with different periods. The light trapped in the SPP modes associated with both top and bottom electrode/organic interfaces are efficiently extracted from the OLEDs by adjusting appropriate periods of two set corrugations, and a 29% enhancement in the current efficiency has been obtained.

Bi, Yan-Gang; Feng, Jing; Liu, Yu-Shan; Li, Yun-Fei; Chen, Yang; Zhang, Xu-Lin; Han, Xiao-Chi; Sun, Hong-Bo

2014-11-01

426

Surface Plasmon-Polariton Mediated Red Emission from Organic Light-Emitting Devices Based on Metallic Electrodes Integrated with Dual-Periodic Corrugation  

PubMed Central

We demonstrate an effective approach to realize excitation and outcoupling of the SPP modes associated with both cathode/organic and anode/organic interfaces in OLEDs by integrating dual-periodic corrugation. The dual-periodic corrugation consists of two set gratings with different periods. The light trapped in the SPP modes associated with both top and bottom electrode/organic interfaces are efficiently extracted from the OLEDs by adjusting appropriate periods of two set corrugations, and a 29% enhancement in the current efficiency has been obtained. PMID:25407776

Bi, Yan-Gang; Feng, Jing; Liu, Yu-Shan; Li, Yun-Fei; Chen, Yang; Zhang, Xu-Lin; Han, Xiao-Chi; Sun, Hong-Bo

2014-01-01

427

Flexible ultrasonic pipe inspection apparatus  

DOEpatents

A flexible, modular ultrasonic pipe inspection apparatus, comprises 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. 7 figs.

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

1998-06-23

428

Pipe crawler with extendable legs  

DOEpatents

A pipe crawler for moving through a pipe in inchworm fashion having front and rear leg assemblies separated by air cylinders to increase and decrease the spacing between assemblies. Each leg of the four legs of an assembly is moved between a wall-engaging, extended position and a retracted position by a separate air cylinder. The air cylinders of the leg assemblies are preferably arranged in pairs of oppositely directed cylinders with no pair lying in the same axial plane as another pair. Therefore, the cylinders can be as long as a leg assembly is wide and the crawler can crawl through sections of pipes where the diameter is twice that of other sections. The crawler carries a valving system, a manifold to distribute air supplied by a single umbilical air hose to the various air cylinders in a sequence controlled electrically by a controller. The crawler also utilizes a rolling mechanism, casters in this case, to reduce friction between the crawler and pipe wall thereby further extending the range of the pipe crawler. 8 figs.

Zollinger, W.T.

1992-06-16

429

Pipe crawler with extendable legs  

DOEpatents

A pipe crawler for moving through a pipe in inchworm fashion having front and rear leg assemblies separated by air cylinders to increase and decrease the spacing between assemblies. Each leg of the four legs of an assembly is moved between a wall-engaging, extended position and a retracted position by a separate air cylinder. The air cylinders of the leg assemblies are preferably arranged in pairs of oppositely directed cylinders with no pair lying in the same axial plane as another pair. Therefore, the cylinders can be as long a leg assembly is wide and the crawler can crawl through sections of pipes where the diameter is twice that of other sections. The crawler carries a valving system, a manifold to distribute air supplied by a single umbilical air hose to the various air cylinders in a sequence controlled electrically by a controller. The crawler also utilizes a rolling mechanism, casters in this case, to reduce friction between the crawler and pipe wall thereby further extending the range of the pipe crawler.

Zollinger, William T. (3927 Almon Dr., Martinez, GA 30907)

1992-01-01

430

Centrally activated pipe snubbing system  

DOEpatents

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.

Cawley, William E. (Richland, WA)

1985-01-01

431

Highly tapered pentagonal bipyramidal Au microcrystals with high index faceted corrugation: Synthesis and optical properties  

NASA Astrophysics Data System (ADS)

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.

Mettela, Gangaiah; Boya, Radha; Singh, Danveer; Kumar, G. V. Pavan; Kulkarni, G. U.

2013-05-01

432

Macroscopic Ordering of Block Copolymers into Sequenced Patterns on Topographically Corrugated Surface  

NASA Astrophysics Data System (ADS)

For the guided block copolymer assembly we used corrugated SiCN ceramic substrates which were fabricated by a facile replication process using non-lithographic PDMS masters. During thermal annealing of polystyrene-b-polybutadiene diblock copolymer, the material transport was guided by the wrinkled substrate to form regular modulations in the film thickness. As a consequence of the thickness-dependent morphological behavior of block copolymers, the film surface appears as sequenced patterns of alternative microphase separated structures. The ordering process is attributed to the formation of reverse terraces which match the substrate topography, so that the resulting surface patterns are free from the surface relief structures within macroscopically-large areas. The issues of the film thickness, the substrate surface energy and the pattern geometry are addressed. Our approach demonstrates an effective synergism of external confinement and internal polymorphism of block copolymers towards complex hierarchically-structured patterned surfaces.

Park, Sungjune; Tsarkova, Larisa; Hiltl, Stephanie; Roitsch, Stefan; Mayer, Joachim; Böker, Alexander

2012-02-01

433

Comparison of finite source and plane wave scattering from corrugated surfaces  

NASA Technical Reports Server (NTRS)

The choice of a plane wave to represent incident radiation in the analysis of scatter from corrugated surfaces was examined. The physical optics solution obtained for the scattered fields due to an incident plane wave was compared with the solution obtained when the incident radiation is produced by a source of finite size and finite distance from the surface. The two solutions are equivalent if the observer is in the far field of the scatterer and the distance from observer to scatterer is large compared to the radius of curvature at the scatter points, condition not easily satisfied with extended scatterers such as rough surfaces. In general, the two solutions have essential differences such as in the location of the scatter points and the dependence of the scattered fields on the surface properties. The implication of these differences to the definition of a meaningful radar cross section was examined.

Levine, D. M.

1977-01-01

434

Energy shift of collective electron excitations in highly corrugated graphitic nanostructures: Experimental and theoretical investigation  

NASA Astrophysics Data System (ADS)

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.

Sedelnikova, O. V.; Bulusheva, L. G.; Asanov, I. P.; Yushina, I. V.; Okotrub, A. V.

2014-04-01

435

Energy shift of collective electron excitations in highly corrugated graphitic nanostructures: Experimental and theoretical investigation  

SciTech Connect

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.

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

436

Theory of the corrugation instability of a piston-driven shock wave  

NASA Astrophysics Data System (ADS)

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.

Bates, J. W.

2015-01-01

437

Atomic corrugation and electron localization due to Moiré patterns in twisted bilayer graphenes  

NASA Astrophysics Data System (ADS)

We report on unprecedentedly large-scale density-functional calculations that clarify atomic and electronic structures of twisted bilayer graphene (BLG). We find the existence of the critical twist angle from either the AB or the AA stacking BLG, above which the two graphene layers are essentially decoupled and below which the atomic planes are corrugated and the Dirac electrons are localized. We also find a magic angle at which the Fermi velocity of the Dirac electron vanishes. We clarify that the Moiré pattern in tBLG with a tiny twist angle generates inhomogeneity for the electron systems and thus causes the drastic modification of the electronic properties, leading to flat bands at the Fermi level. Sensitivity to the Moiré of the valence-electron density and the electron state near the Fermi level is discussed.

Uchida, Kazuyuki; Furuya, Shinnosuke; Iwata, Jun-Ichi; Oshiyama, Atsushi

2014-10-01

438

Highly tapered pentagonal bipyramidal Au microcrystals with high index faceted corrugation: Synthesis and optical properties  

PubMed Central

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.

Mettela, Gangaiah; Boya, Radha; Singh, Danveer; Kumar, G. V. Pavan; Kulkarni, G. U.

2013-01-01

439

Theory of the corrugation instability of a piston-driven shock wave.  

PubMed

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>h(c), where h is the D'yakov parameter and h(c) 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. PMID:25679715

Bates, J W

2015-01-01

440

46 CFR 154.512 - Piping: Thermal isolation.  

Code of Federal Regulations, 2010 CFR

...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...

2010-10-01

441

46 CFR 154.512 - Piping: Thermal isolation.  

Code of Federal Regulations, 2011 CFR

...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...

2011-10-01

442

46 CFR 154.512 - Piping: Thermal isolation.  

Code of Federal Regulations, 2012 CFR

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

2012-10-01

443

46 CFR 154.512 - Piping: Thermal isolation.  

Code of Federal Regulations, 2014 CFR

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

2014-10-01

444

46 CFR 154.512 - Piping: Thermal isolation.  

Code of Federal Regulations, 2013 CFR

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

2013-10-01

445

46 CFR 154.522 - Materials for piping.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Materials for piping. 154.522 Section 154.522 Shipping...Construction and Equipment Cargo and Process Piping Systems § 154.522 Materials for piping. (a) The materials for piping...

2011-10-01

446

46 CFR 153.281 - Piping to independent tanks.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Piping to independent tanks. 153.281 Section...HAZARDOUS MATERIALS Design and Equipment Piping Systems and Cargo Handling Equipment § 153.281 Piping to independent tanks. Piping...

2012-10-01

447

46 CFR 154.522 - Materials for piping.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Materials for piping. 154.522 Section 154.522 Shipping...Construction and Equipment Cargo and Process Piping Systems § 154.522 Materials for piping. (a) The materials for piping...

2013-10-01

448

46 CFR 119.720 - Nonmetallic piping materials.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Nonmetallic piping materials. 119.720 Section 119.720...THAN 49 PASSENGERS MACHINERY INSTALLATION Piping Systems § 119.720 Nonmetallic piping materials. Nonmetallic piping...

2010-10-01

449

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 153...HAZARDOUS MATERIALS Design and Equipment Piping Systems and Cargo Handling Equipment § 153.292 Separation of piping systems. Cargo piping...

2013-10-01

450

46 CFR 154.548 - Cargo piping: Flow capacity.  

Code of Federal Regulations, 2013 CFR

...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...

2013-10-01

451

46 CFR 153.292 - Separation of piping systems.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Separation of piping systems. 153.292 Section 153...HAZARDOUS MATERIALS Design and Equipment Piping Systems and Cargo Handling Equipment § 153.292 Separation of piping systems. Cargo piping...

2011-10-01

452

46 CFR 119.720 - Nonmetallic piping materials.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Nonmetallic piping materials. 119.720 Section 119.720...THAN 49 PASSENGERS MACHINERY INSTALLATION Piping Systems § 119.720 Nonmetallic piping materials. Nonmetallic piping...

2011-10-01

453

46 CFR 153.281 - Piping to independent tanks.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Piping to independent tanks. 153.281 Section...HAZARDOUS MATERIALS Design and Equipment Piping Systems and Cargo Handling Equipment § 153.281 Piping to independent tanks. Piping...

2011-10-01

454

46 CFR 154.548 - Cargo piping: Flow capacity.  

Code of Federal Regulations, 2012 CFR

...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...

2012-10-01

455

46 CFR 119.720 - Nonmetallic piping materials.  

Code of Federal Regulations, 2012 CFR

...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...

2012-10-01

456

46 CFR 154.522 - Materials for piping.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Materials for piping. 154.522 Section 154.522 Shipping...Construction and Equipment Cargo and Process Piping Systems § 154.522 Materials for piping. (a) The materials for piping...

2010-10-01

457

46 CFR 153.292 - Separation of piping systems.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Separation of piping systems. 153.292 Section 153...HAZARDOUS MATERIALS Design and Equipment Piping Systems and Cargo Handling Equipment § 153.292 Separation of piping systems. Cargo piping...

2010-10-01

458

46 CFR 95.16-60 - System piping installation testing.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false System piping installation testing. 95.16-60...Systems, Details § 95.16-60 System piping installation testing. (a) Halocarbon...conducted on halocarbon system discharge piping on completion of piping...

2014-10-01

459

46 CFR 154.522 - Materials for piping.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false Materials for piping. 154.522 Section 154.522 Shipping...Construction and Equipment Cargo and Process Piping Systems § 154.522 Materials for piping. (a) The materials for piping...

2014-10-01

460

46 CFR 119.720 - Nonmetallic piping materials.  

Code of Federal Regulations, 2013 CFR

...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...

2013-10-01

461

46 CFR 95.16-60 - System piping installation testing.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false System piping installation testing. 95.16-60...Systems, Details § 95.16-60 System piping installation testing. (a) Halocarbon...conducted on halocarbon system discharge piping on completion of piping...

2012-10-01

462

46 CFR 153.281 - Piping to independent tanks.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false Piping to independent tanks. 153.281 Section...HAZARDOUS MATERIALS Design and Equipment Piping Systems and Cargo Handling Equipment § 153.281 Piping to independent tanks. Piping...

2014-10-01

463

46 CFR 153.281 - Piping to independent tanks.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Piping to independent tanks. 153.281 Section...HAZARDOUS MATERIALS Design and Equipment Piping Systems and Cargo Handling Equipment § 153.281 Piping to independent tanks. Piping...

2010-10-01

464

46 CFR 154.548 - Cargo piping: Flow capacity.  

Code of Federal Regulations, 2014 CFR

...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...

2014-10-01

465

46 CFR 154.522 - Materials for piping.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Materials for piping. 154.522 Section 154.522 Shipping...Construction and Equipment Cargo and Process Piping Systems § 154.522 Materials for piping. (a) The materials for piping...

2012-10-01

466

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 153...HAZARDOUS MATERIALS Design and Equipment Piping Systems and Cargo Handling Equipment § 153.292 Separation of piping systems. Cargo piping...

2014-10-01

467

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 153...HAZARDOUS MATERIALS Design and Equipment Piping Systems and Cargo Handling Equipment § 153.292 Separation of piping systems. Cargo piping...

2012-10-01

468

46 CFR 154.548 - Cargo piping: Flow capacity.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 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...

2011-10-01

469

46 CFR 119.720 - Nonmetallic piping materials.  

Code of Federal Regulations, 2014 CFR

...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...

2014-10-01

470

46 CFR 153.281 - Piping to independent tanks.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Piping to independent tanks. 153.281 Section...HAZARDOUS MATERIALS Design and Equipment Piping Systems and Cargo Handling Equipment § 153.281 Piping to independent tanks. Piping...

2013-10-01

471

46 CFR 95.16-60 - System piping installation testing.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false System piping installation testing. 95.16-60...Systems, Details § 95.16-60 System piping installation testing. (a) Halocarbon...conducted on halocarbon system discharge piping on completion of piping...

2013-10-01

472

46 CFR 56.15-1 - Pipe joining fittings.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Pipe joining fittings. ...CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND...Fittings § 56.15-1 Pipe joining fittings. ...square inch gage. (c) Pipe joining fittings not...or produce a primary stress greater than...

2012-10-01

473

46 CFR 56.15-1 - Pipe joining fittings.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 false Pipe joining fittings. ...CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND...Fittings § 56.15-1 Pipe joining fittings. ...square inch gage. (c) Pipe joining fittings not...or produce a primary stress greater than...

2014-10-01

474

46 CFR 56.15-1 - Pipe joining fittings.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Pipe joining fittings. ...CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND...Fittings § 56.15-1 Pipe joining fittings. ...square inch gage. (c) Pipe joining fittings not...or produce a primary stress greater than...

2013-10-01

475

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

476

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

477

46 CFR 119.455 - Fuel piping.  

Code of Federal Regulations, 2010 CFR

...such as seamless steel pipe or tubing...fuel piping of aluminum is acceptable on aluminum hull vessels provided...protect against corrosion. Where passing...bowls of other than steel construction must...bowls of other than steel construction...

2010-10-01

478

Polyethylene Encasement for Cast-Iron Pipe  

Microsoft Academic Search

External corrosion of buried iron pipe can occur if an area's soil is corrosive. To help protect pipe against electrolytic current, the use of polyethylene encasement is recommended. Standard specifications developed for this product are reviewed in the following.

Walter Amory

1976-01-01

479

Duality of antidiagonals and pipe dreams  

Microsoft Academic Search

Weighted enumeration of reduced pipe dreams (or rc-graphs) results in a combinatorial expression for Schubert polynomials. The duality between the set of reduced pipe dreams and certain antidiagonals has important geometric implications [A. Knutson and E. Miller, Gr\\\\\\

Ning Jia; Ezra Miller

2007-01-01

480

49 CFR 192.281 - Plastic pipe.  

Code of Federal Regulations, 2010 CFR

A plastic pipe joint that is joined by solvent cement, adhesive, or heat fusion may not be disturbed until it has properly set. Plastic pipe may not be joined by a threaded joint or miter joint. (b) Solvent cement...

2010-10-01

481

49 CFR 192.281 - Plastic pipe.  

Code of Federal Regulations, 2012 CFR

A plastic pipe joint that is joined by solvent cement, adhesive, or heat fusion may not be disturbed until it has properly set. Plastic pipe may not be joined by a threaded joint or miter joint. (b) Solvent cement...

2012-10-01

482

49 CFR 192.281 - Plastic pipe.  

Code of Federal Regulations, 2013 CFR

A plastic pipe joint that is joined by solvent cement, adhesive, or heat fusion may not be disturbed until it has properly set. Plastic pipe may not be joined by a threaded joint or miter joint. (b) Solvent cement...

2013-10-01

483

49 CFR 192.281 - Plastic pipe.  

Code of Federal Regulations, 2011 CFR

A plastic pipe joint that is joined by solvent cement, adhesive, or heat fusion may not be disturbed until it has properly set. Plastic pipe may not be joined by a threaded joint or miter joint. (b) Solvent cement...

2011-10-01

484

49 CFR 192.281 - Plastic pipe.  

Code of Federal Regulations, 2014 CFR

A plastic pipe joint that is joined by solvent cement, adhesive, or heat fusion may not be disturbed until it has properly set. Plastic pipe may not be joined by a threaded joint or miter joint. (b) Solvent cement...

2014-10-01

485

46 CFR 108.447 - Piping.  

Code of Federal Regulations, 2010 CFR

...SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.447 Piping. (a) Each pipe, valve, and fitting in a CO2...

2010-10-01

486

The Design and Analysis of a Feeder Pipe Inspection Robot With an Automatic Pipe Tracking System  

Microsoft Academic Search

The feeder pipes in a pressurized heavy water reactor (PHWR) suffer from flow-assisted corrosion (FAC), which makes the wall thickness of the pipes thin. This effect is a well-known degradation mechanism of a carbon pipe with high pressure and high flow rate. Therefore, the weak parts of the pipe should be measured to guarantee the safety. This paper describes a

Changhwan Choi; Seungho Jung

2010-01-01

487

Cryogenic thermal diode heat pipes  

NASA Technical Reports Server (NTRS)

The development of spiral artery cryogenic thermal diode heat pipes was continued. Ethane was the working fluid and stainless steel the heat pipe material in all cases. The major tasks included: (1) building a liquid blockage (blocking orifice) thermal diode suitable for the HEPP space flight experiment; (2) building a liquid trap thermal diode engineering model; (3) retesting the original liquid blockage engineering model, and (4) investigating the startup dynamics of artery cryogenic thermal diodes. An experimental investigation was also conducted into the wetting characteristics of ethane/stainless steel systems using a specially constructed chamber that permitted in situ observations.

Alario, J.

1979-01-01

488

Analysis of Municipal Pipe Network Franchise Institution  

NASA Astrophysics Data System (ADS)

Franchise institution of municipal pipe network has some particularity due to the characteristic of itself. According to the exposition of Chinese municipal pipe network industry franchise institution, the article investigates the necessity of implementing municipal pipe network franchise institution in China, the role of government in the process and so on. And this offers support for the successful implementation of municipal pipe network franchise institution in China.

Yong, Sun; Haichuan, Tian; Feng, Xu; Huixia, Zhou

489

Dynamics of heat-pipe reactors  

NASA Technical Reports Server (NTRS)

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.

Niederauer, G. F.

1971-01-01

490

Gray Cast-Iron Water Pipe Metallurgy  

Microsoft Academic Search

Abstract: The results of a,metallographic study of grey,cast iron water pipes are reported. These pipes had been installed between 1885 and 1973 in eight different water systems. Each pipe had been extracted during scheduled maintenance,or failure repairs to provide data for a larger study toproduce,a methodology ,for determining ,the residual life of grey ,cast iron pipes. This metallographic study was

J. M. Rajani

2000-01-01

491

Heat pipe heat exchanger design considerations  

Microsoft Academic Search

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

K. T. Feldman; D. C. Lu

1976-01-01

492

Thermal Performance of High Temperature Titanium-Water Heat Pipes by Multiple Heat Pipe Manufacturers  

NASA Technical Reports Server (NTRS)

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.

Sanzi, James L.

2007-01-01

493

Thermal Performance of High Temperature Titanium -- Water Heat Pipes by Multiple Heat Pipe Manufacturers  

NASA Technical Reports Server (NTRS)

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.

Sanzi, James L.

2007-01-01

494

49 CFR 192.279 - Copper pipe.  

Code of Federal Regulations, 2010 CFR

...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...

2010-10-01

495

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...

496

46 CFR 193.15-15 - Piping.  

Code of Federal Regulations, 2014 CFR

...Shipping 7 2014-10-01 2014-10-01 false Piping. 193.15-15 Section 193.15-15 Shipping...Extinguishing Systems, Details § 193.15-15 Piping. (a) The piping, valves, and fittings shall have a bursting...

2014-10-01

497

14 CFR 25.1123 - Exhaust piping.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Exhaust piping. 25.1123 Section 25.1123 Aeronautics...Exhaust System § 25.1123 Exhaust piping. For powerplant and auxiliary power...the following apply: (a) Exhaust piping must be heat and corrosion...

2011-01-01

498

46 CFR 132.110 - Piping.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Piping. 132.110 Section 132.110 Shipping...EQUIPMENT Fire Main § 132.110 Piping. (a) Except as provided for liftboats...each fitting, flange, valve, and run of piping must meet the applicable...

2010-10-01

499

46 CFR 76.25-30 - Piping.  

Code of Federal Regulations, 2012 CFR

...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...

2012-10-01

500

Pipe viscometry of foams C. Enzendorfer  

E-print Network

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

Valkó, Peter