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1

Comparative Studies on Corrugated Metal Culvert Pipes.  

National Technical Information Service (NTIS)

The objective of this study was to perform comparative tests to ascertain the controlling geometric and mechanical parameters that govern the structural performance of three types of flexible pipe; namely, spiral corrugated metal pipe, riveted corrugated ...

W. W. Lane

1965-01-01

2

CULVERT INLET SHOWING THREE CORRUGATED METAL STAND PIPES. VIEW TO ...  

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

CULVERT INLET SHOWING THREE CORRUGATED METAL STAND PIPES. VIEW TO THE SOUTHWEST. 18 - Burlington Northern Santa Fe Railroad, Cajon Subdivision , Structure 58.1X, Between Cajon Summit and Keenbrook, Devore, San Bernardino County, CA

3

CASE STUDY: HYDRAULIC ANALYSIS OF A CORRUGATED METAL PIPE (CMP) CIPP-LINED CULVERT  

Microsoft Academic Search

3 ABSTRACT: Recent successful CIPP lining of a CMP culvert led to an interest in determining the hydraulic characteristics of the lined culverts. Measurements of the CIPP liner's wall-roughness and cross-sectional geometry permitted development of a preliminary evaluation of the hydraulic performance of the CIPP lined pipes. The overall approach was to compare the hydraulic characteristics of the CIPP- lined

Mohammad Najafi; Roger Wallace; Rick Baxter

4

Singing Corrugated Pipes  

ERIC Educational Resources Information Center

Presents theoretical and experimental observations made with a musical toy called Hummer consisting of a corrugated flexible plastic tube about three-feet long and one-inch diam open at both ends. Included are descriptions of three new instruments: the Water Pipe, the Gas-Pipe Corrugahorn Bugle, and the Gas-Pipe Blues Corrugahorn. (CC)

Crawford, Frank S.

1974-01-01

5

Culvert Pipe Liner Guide and Specifications.  

National Technical Information Service (NTIS)

Trenchless technology can be used with a wide range of methods, materials, and equipment for rehabilitation or replacement of damaged or deteriorated pipe culverts. To date, several trenchless lining techniques have been used for the rehabilitation of exi...

B. A. Smith C. I. Thornton I. G. Girard M. D. Robeson

2005-01-01

6

Singing corrugated pipes revisited  

NASA Astrophysics Data System (ADS)

A long corrugated tube open at both ends sings notes which depend on the flow velocity of air flowing through the tube. The notes it sings are natural harmonics of the tube. In 1974, Crawford suggested an explanation for this: A given note will sing when the flow velocity is such that the ``bump frequency'' equals the frequency of the note, provided also that the flow velocity is sufficiently high to induce turbulent flow. He suggested two theories to explain the singing in terms of turbulence. One assumed that the onset of turbulence agrees with the classic Reynolds number for smooth tubes (Rsmooth~=2000) in which the characteristic length of the object that has air flowing in is equal to the diameter. The second assumed the characteristic length of the object was equal to the distance between the corrugations. Crawford reported having good agreement between the classic diameter-induced turbulence theory and experiment for some pipes. However, for other tubes he observed singing at Reynolds numbers that were much smaller than the classical result of 2000. For these, he could not establish if he was observing corrugation-induced turbulence. (He stated he did not have sufficient pipes.) After looking at a variety of tube diameters and corrugation lengths, we also observed (as Crawford reported) that some of the data agreed with the classic diameter-induced turbulence, and some did not. Ironically, the hypothesis Crawford introduced (and rejected) as an alternative possibility seems to fit ALL of our data quite well. A new Reynolds number associated with the onset of turbulence for corrugated pipes is presented: Rcorr~=500.

Cadwell, Louis H.

1994-03-01

7

Corrugated pipe adhesive applicator apparatus  

Microsoft Academic Search

Apparatus for coating selected portions of the troughs of a corrugated pipe within an adhesive includes a support disposed within the pipe with a reservoir containing the adhesive disposed on the support. A pump, including a spout, is utilized for supplying the adhesive from the reservoir to a trough of the pipe. A rotatable applicator is supported on the support

Shirey; Ray A

1983-01-01

8

Corrugated pipe adhesive applicator apparatus  

Microsoft Academic Search

Apparatus for coating selected portions of the troughs of a corrugated pipe with an adhesive includes a support disposed within the pipe with a reservoir containing the adhesive disposed on the support. A pump, including a spout, is utilized for supplying the adhesive from the reservoir to a trough of the pipe. A rotatable applicator is supported on the support

Shirey

1983-01-01

9

Symposium on Durability of Culverts and Storm Drains.  

National Technical Information Service (NTIS)

The 18 papers in this report deal with the following areas: culvert durability: where are we; durability of polymer-coated corrugated steel pipe; durability of drainage structures; overview of polymer coatings for corrugated steel pipe in New York; durabi...

G. W. Ring C. M. Hirsch K. M. Jacobs R. M. Pyskadlo W. W. Renfrew

1984-01-01

10

Singing corrugated pipes revisited  

Microsoft Academic Search

A long corrugated tube open at both ends sings notes which depend on the flow velocity of air flowing through the tube. The notes it sings are natural harmonics of the tube. In 1974, Crawford suggested an explanation for this: A given note will sing when the flow velocity is such that the ``bump frequency'' equals the frequency of the

Louis H. Cadwell

1994-01-01

11

Singing Corrugated Pipes  

Microsoft Academic Search

A corrugated tube open at both ends, with air flowing through the tube, sings notes which depend on the flow velocity and the length of the tube. The notes it sings are the natural harmonics of the tube. A given note will sing when the flow velocity is such that the ``bump frequency'' (frequency at which the air bumps into

Frank S. Crawford

1974-01-01

12

Behavior of a Corrugated-Metal Box Culvert.  

National Technical Information Service (NTIS)

Strain and deflection were determined for a 22-ft 3-in. aluminum box culvert during backfilling and under static live load. The structure was instrumented at the crown and haunches with electrical-resistance strain gages on the structural plates and stiff...

D. B. Beal

1986-01-01

13

Corrugated pipe adhesive applicator apparatus  

DOEpatents

Apparatus for coating selected portions of the troughs of a corrugated pipe within an adhesive includes a support disposed within the pipe with a reservoir containing the adhesive disposed on the support. A pump, including a spout, is utilized for supplying the adhesive from the reservoir to a trough of the pipe. A rotatable applicator is supported on the support and contacts the trough of the pipe. The applicator itself is sized so as to fit within the trough, and contacts the adhesive in the trough and spreads the adhesive in the trough upon rotation. A trough shield, supported by the support and disposed in the path of rotation of the applicator, is utilized to prevent the applicator from contacting selected portions of the trough. A locator head is also disposed on the support and provides a way for aligning the spout, the applicator, and the trough shield with the trough.

Shirey, Ray A. (North Grafton, MA)

1983-06-14

14

Corrugated pipe adhesive applicator apparatus  

DOEpatents

Apparatus for coating selected portions of the troughs of a corrugated pipe with an adhesive includes a support disposed within the pipe with a reservoir containing the adhesive disposed on the support. A pump, including a spout, is utilized for supplying the adhesive from the reservoir to a trough of the pipe. A rotatable applicator is supported on the support and contacts the trough of the pipe. The applicator itself is sized so as to fit within the trough, and contacts the adhesive in the trough and spreads the adhesive in the trough upon rotation. A trough shield, supported by the support and disposed in the path of rotation of the applicator, is utilized to prevent the applicator from contacting selected portions of the trough. A locator head is also disposed on the support and provides a way for aligning the spout, the applicator, and the trough shield with the trough. 4 figs.

Shirey, R.A.

1983-06-14

15

Culvert Distress and Failure Case Histories and Trenchless Technology.  

National Technical Information Service (NTIS)

Contents: Investigation of Large Deformations of a Corrugated Metal Pipe in Silty Soil; Lessons Learned from Culvert Failures and Nonfailures; Pipe Failure Caused by Improper Groundwater Control; Backfill Placement Methods Lead to Flexible Pipe Distortion...

1994-01-01

16

Instabilities of flow in a corrugated pipe  

NASA Astrophysics Data System (ADS)

Flow in a corrugated pipe is considered. Different from previous studies, both the corrugation amplitude and wavelength are much smaller than the pipe diameter. Results of the multi-scale analysis show that the mean flow modulated by the surface corrugation becomes unstable to three-dimensional travelling waves at moderate Reynolds numbers, and the wave with one azimuthal period is found to be the most unstable mode.

Tao, Jianjun

17

Corrugated Pipe as a Beam Dechirper  

Microsoft Academic Search

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

K. L. F. Bane; G. Stupakov

2012-01-01

18

Failure Characteristics of a Structural Plate Pipe Arch Culvert.  

National Technical Information Service (NTIS)

An existing 37 year old, 15.67 ft. span, 9.58 ft. rise structural plate pipe arch culvert installed in cohesive backfill material was instrumented with biaxial electric strain gages and position transducers and loaded with two hydraulic cylinders, simulat...

S. M. Sargand G. A. Hazen

1992-01-01

19

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

20

Corrugated pipe as a beam dechirper  

NASA Astrophysics Data System (ADS)

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 wavelength, even when the aperture is small. We showed how the corrugated structure can satisfy dechirping requirements encountered in the NGLS project at LBNL [1]. We found that a linear chirp of ?40MeV/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?m and period 1000?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.

2012-10-01

21

Hydraulic Resistance of Small-Diameter Helically Corrugated Metal Pipe.  

National Technical Information Service (NTIS)

The hydraulic resistance of helical CMP is strongly dependent on helix angle the angle of the corrugations relative to the longitudinal axis of the pipe. Smaller-diameter pipes have smaller helix angles. Helical corrugations with a significant downstream ...

B. M. McEnroe T. Malone

2008-01-01

22

Stokes slip flow in a corrugated pipe  

Microsoft Academic Search

In vitro measurements in the context of blood flows, performed in micro fabricated microchannels are subject to the channel-walls exhibiting some degree of roughness. Interestingly it is realistic to note that microdomains such as arteries and capillaries are prone to constrictions for various pathological reasons. Such microdomained flow problems may be studied as flows through axially corrugated pipes using continuum

M. Vasudeviah; K. Balamurugan

1999-01-01

23

78 FR 5715 - Construction and Maintenance-Culvert Pipe Selection  

Federal Register 2010, 2011, 2012, 2013

...have the autonomy to determine culvert and storm sewer material types to be included in...411 to allow States to choose culvert and storm sewer material type. The regulatory amendments...have the autonomy to determine culvert and storm sewer material types to be included...

2013-01-28

24

Establishing 100Year Service Life for Corrugated HDPE Drainage Pipe  

Microsoft Academic Search

The design service life of corrugated high density polyethylene (HDPE) drainage pipe has been a subject of considerable debate and research over the past several years. While significant long-term performance data is available for smooth-walled polyethylene pipe, the data for corrugated drainage pipes is somewhat limited. This paper presents a method for determination of long-term service life of corrugated HDPE

Michael Pluimer

25

Squaw Creek Culvert Fish Passage Improvement Project. Squaw Creek, Little Salmon River Subbasin North Central Idaho. Completion Report.  

National Technical Information Service (NTIS)

The Squaw Creek culvert fish passage improvement project replaced a perched corrugated metal pipe culvert that was impeding fish passage in Squaw Creek, a tributary to the Little Salmon River, with a bottomless arch culvert. The project was approved and i...

2008-01-01

26

Experiments on sound generation in corrugated pipes with flow.  

PubMed

The article reports acoustic measurements on short corrugated pipes with flow. Such pipes might generate high sound levels associated with length resonances. One of the main objectives of the study was to estimate the location of the effective sources by studying the energy flow through the pipes. It was found that a short section of corrugations will only produce sound effectively when placed at the inflow end, while for fully corrugated pipes, the sound-producing regions are located around the pressure maxima of the observed standing waves. It was further found that the net energy flow is in the upstream direction for nearly the complete length of pipe. PMID:17407869

Kristiansen, Ulf R; Wiik, Geir A

2007-03-01

27

Coupling impedances for corrugated beam pipes from impedance boundary conditions  

Microsoft Academic Search

An equivalent wall impedance describing the electromagnetic boundary conditions at corrugated pipe walls is introduced in the context of a general perturbative approach for computing the longitudinal and transverse beam coupling impedances in complex heterogeneous pipes.

S. Petracca; Th. Demma

2003-01-01

28

Impedance issue of corrugated beam pipe from CDF  

Microsoft Academic Search

The CDF collaboration proposed to install a new corrugated beam pipe at the Tevatron interaction area in order to better monitor the interaction vertex. This note discuss the impedance implication of such a pipe.

King-Yuen

1993-01-01

29

Mitigation of Roadway Settlement Above Buried Culverts and Pipes.  

National Technical Information Service (NTIS)

The report identifies the likely causes of settlement and roadway damage at culvert sites on Wyoming highways. These causes are: Poor material used as backfill around and above culverts; Inadequate compaction; Low soil cover, as defined as 5m or less. Bas...

J. F. Lundvall J. P. Turner

1997-01-01

30

Stability of steady flow through an axially corrugated pipe  

Microsoft Academic Search

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

S. A. Loh; H. M. Blackburn

2011-01-01

31

Soil–structure interaction for deeply buried corrugated steel pipes Part I: Embankment installation  

Microsoft Academic Search

The strengths of buried corrugated steel pipes were studied. There are considerable differences in the fundamental mechanics of earth pressure distribution on rigid pipes and flexible pipes. Corrugated steel pipes are categorized as semi-flexible. The mechanics of soil arching for corrugated steel pipes, therefore, are slightly different from rigid or flexible pipes. Predictor equations for arching factors, deflections, and maximum

Junsuk Kang; Frazier Parker; Chai H. Yoo

2008-01-01

32

Durability of Bituminous-Lined Corrugated Steel Pipe Storm Sewers.  

National Technical Information Service (NTIS)

In 1983, the Ohio Department of Transportation (ODOT) initiated a study to determine the durability of bituminous lined corrugated steel pipe storm sewers at various sites in Ohio. The study involved field inspection and analysis of representative bitumin...

S. L. Zeid M. S. Macy

1985-01-01

33

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

34

RECENT FAILURES OF LARGE CORRUGATED METAL PIPE SPILLWAYS  

Microsoft Academic Search

Many new stormwater management dams in Maryland have been constructed with large diameter corrugated metal pipe (CMP) spillways. Several of these dams, all 'dry' ponds that impound water only during storms, have recently failed by piping of embankment soils along the outside of the conduit or through leaky joints. Random inspections have revealed serious deficiencies in many of the structures.

Harald W. Van Aller

35

Energy losses and heat transfer enhancement in transversally corrugated pipes  

Microsoft Academic Search

Wall friction, temperature distribution and heat transfer through pipe walls are investigated in forced convection with Newtonian fluids in pressure gradient driven hydrodynamically and thermally fully developed steady laminar flow in transversally corrugated pipes. Novel analytical solutions derived via the epitrochoid conformal mapping are presented for the velocity and temperature fields. Analytical results are compared with numerical solutions obtained using

F. Talay Akyildiz; Dennis A. Siginer; Lyes Khezzar

2011-01-01

36

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

37

Corrosion of Spiral Rib Aluminized Pipe, Summary Report.  

National Technical Information Service (NTIS)

Large diameter, corrugated steel pipes are a common sight in the culverts that run alongside many Florida roads. Spiral-ribbed aluminized pipe (SRAP) has been widely specified by the Florida Department of Transportation (FDOT) for runoff drainage. These p...

A. A. Sagues

2012-01-01

38

Evaluation of Plastic Piping for Culverts and Storm Sewers.  

National Technical Information Service (NTIS)

An overview of the current issues of HDPE pipe-soil systems is followed by a comprehensive review addressing current specifications, design methods, and relevant research projects. The following experimental tasks were carried out: (1) environmental stres...

D. V. Reddy

1999-01-01

39

Soil–structure interaction for deeply buried corrugated steel pipes Part II: Imperfect trench installation  

Microsoft Academic Search

The potential benefits of the imperfect trench installation method were studied for corrugated steel pipes. The imperfect trench installation method has mostly been used to reduce earth pressure on buried rigid pipes by inducing reverse soil arching over the pipe. Because corrugated steel pipes are relatively flexible, they induce a small amount of reverse soil arching. Therefore, there has been

Junsuk Kang; Frazier Parker; Chai H. Yoo

2008-01-01

40

Salmon Passage through Culverts.  

National Technical Information Service (NTIS)

The primary objective of this study was to assess the problems associated with salmon passage through hydraulic structures, primarily corrugated culverts, on steep gradient streams in Alaska. The problem is that considerable habitat for juvenile salmon an...

C. E. Behlke D. L. Kane

1994-01-01

41

Responses of buried corrugated metal pipes to earthquakes  

Microsoft Academic Search

This study describes the results of field investigations and analyses carried out on 61 corrugated metal pipes (CMP) that were shaken by the 1994 Northridge earthquake. These CMPs, which include 29 small-diameter (below 107 cm) CMPs and 32 large-diameter (above 107 cm) CMPs, are located within a 10 km² area encompassing the Van Normal Complex in the Northern San Fernando

C. A. Davis; J. P. Bardet

2000-01-01

42

Radiation characteristics of a dielectric sphere-loaded corrugated pipe  

Microsoft Academic Search

The fields radiated by a feed structure consisting of a dielectric sphere placed in front of, but displaced from, the open end of a corrugated pipe with quarter-wave teeth, carrying the HE11mode, are derived. It is shown that this feed system has near-circular far-field characteristics with increased on-axis gain. The feed also has a reduced input VSWR due to the

P. Neelakantaswamy; D. Banerjee

1975-01-01

43

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

44

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

NASA Astrophysics Data System (ADS)

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 modeling. The side branch depth is chosen to be equal to the side branch diameter, which corresponds to cavity geometries in typical corrugated pipes. The low frequency resonance modes of the multiple side branch system have been predicted by means of acoustic models, of which the validity has been tested experimentally. Several experiments have been carried out for characterizing the whistling behavior of the system. While the behavior of a multiple side branch system is interesting on its own it can be compared to that of corrugated pipes. These experiments show that the multiple side branch system is in many aspects a reasonable model for corrugated pipes. Advantage of the multiple side branch system is that it is an experimental setup allowing easy modification of cavity depth. We used this feature to identify the pressure nodes of the acoustic standing wave along the main pipe as the regions where sound is produced. This contradicts recent publications on corrugated pipes. Another interesting aspects is that the system appears to whistle at the second hydrodynamic mode of the cavities rather than at the first hydrodynamic mode. A prediction model for the whistling behavior is proposed, consisting of an energy balance, based on the vortex sound theory. The model predicts the observed Strouhal number but overestimates the acoustic fluctuation amplitude by a factor four.

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

2010-04-01

45

Structural effects of concrete lining for concrete-lined corrugated steel pipes  

Microsoft Academic Search

This article presents the results of an analytical study on the structural behaviour of buried concrete-lined corrugated steel pipe (CLCSP). CLCSP combines the hydraulic characteristics of concrete pipe with an extended service life compared to unlined corrugated pipe. It is typically factory manufactured and shipped to the jobsite for roadway drainage applications. However, recent investigations have also demonstrated the ability

J. S. Kang; J. S. Davidson

2010-01-01

46

Terahertz radiation from a pipe with small corrugations  

NASA Astrophysics Data System (ADS)

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 ˜1THz, 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 ˜1GW. 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.

2012-06-01

47

EVALUATE THE LONG-TERM STRESS CRACK RESISTANCE OF CORRUGATED HDPE PIPES  

Microsoft Academic Search

The 100-year stress crack resistance (SCR) of corrugated HDPE pipes was evaluated using a 600 mm diameter pipe. The SCR tests were performed on the finished pipe at the liner and junction locations. The notched constant ligament stress (NCLS) test (ASTM 2163) was used for the pipe liner assessment. For the pipe junction, a new test method was developed to

Y. Grace Hsuan; J-Y Zhang; W-K Wong

48

On the radiation from an open-ended corrugated pipe carrying the HE11mode  

Microsoft Academic Search

The fields radiated by anHE_{11}mode in an aperture of a corrugated pipe with quarter-wave teeth are derived by considering the pipe to be situated in an infinite perfectly conducting ground plane. Unlike the case for a smooth wall pipe, this model is reasonable since the corrugations force the edge taper in theEplane of the pipe's aperture to be significantly increased

C. Knop; H. Wiesenfarth

1972-01-01

49

EXPERIMENTAL STUDY OF THE FLOW-EXCITED ACOUSTICAL LOCK-IN IN A CORRUGATED PIPE  

Microsoft Academic Search

Preliminary experiments to study the aero-acoustic interaction in a corrugated pipe subjected to axial flow are reported. A number of pipes of different diameters, lengths and corrugation pitches and shapes are tested. Results are presented in the light of previous work and the aero- acoustic instability Strouhal numbers are evaluated. We notice that not a single value St is applicable

Vincent Debut; José Antunes; Miguel Moreira

50

Responses of buried corrugated metal pipes to earthquakes  

SciTech Connect

This study describes the results of field investigations and analyses carried out on 61 corrugated metal pipes (CMP) that were shaken by the 1994 Northridge earthquake. These CMPs, which include 29 small-diameter (below 107 cm) CMPs and 32 large-diameter (above 107 cm) CMPs, are located within a 10 km{sup 2} area encompassing the Van Normal Complex in the Northern San Fernando Valley, in Los Angeles, California. During the Northridge earthquake, ground movements were extensively recorded within the study area. Twenty-eight of the small-diameter CMPs performed well while the 32 large-diameter CMPs underwent performances ranging from no damage to complete collapse. The main cause of damage to the large-diameter CMPs was found to be the large ground strains. Based on this unprecedented data set, the factors controlling the seismic performance of the 32 large-diameter CMPs were identified and framed into a pseudostatic analysis method for evaluating the response of large diameter flexible underground pipes subjected to ground strain. The proposed analysis, which is applicable to transient and permanent strains, is capable of describing the observed performance of large-diameter CMPs during the 1994 Northridge earthquake. It indicates that peak ground velocity is a more reliable parameter for analyzing pipe damage than is peak ground acceleration. Results of this field investigation and analysis are useful for the seismic design and strengthening of flexible buried conduits.

Davis, C.A.; Bardet, J.P.

2000-01-01

51

Culverts and Tiebacks.  

National Technical Information Service (NTIS)

The 20 papers in the report deal with the following areas: Some observations on flexible pipe response to load; Load test report and evaluation of a precast concrete arch culvert; Failure of flexible long-span culverts under exceptional live loads; Allowa...

C. D. F. Rogers T. J. Beach R. B. Seed J. R. Raines M. G. Katona

1988-01-01

52

Pressure drop of slush nitrogen flow in converging-diverging pipes and corrugated pipes  

NASA Astrophysics Data System (ADS)

Cryogenic slush fluids such as slush hydrogen and slush nitrogen are solid-liquid, two-phase fluids. As a functional thermal fluid, there are high expectations for use of slush fluids in various applications such as fuels for spacecraft engines, clean-energy fuels to improve the efficiency of transportation and storage, and as refrigerants for high-temperature superconducting equipment. Experimental flow tests were performed using slush nitrogen to elucidate pressure-drop characteristics of converging-diverging (C-D) pipes and corrugated pipes. In experimental results regarding pressure drop in two different types of C-D Pipes, i.e., a long-throated pipe and a short-throated pipe, each having an inner diameter of 15 mm, pressure drop for slush nitrogen in the long-throated pipe at a flow velocity of over 1.3 m/s increased by a maximum of 50-60% as compared to that for liquid nitrogen, while the increase was about 4 times as compared to slush nitrogen in the short-throated pipe. At a flow velocity of over 1.5 m/s in the short-throated pipe, pressure drop reduction became apparent, and it was confirmed that the decrease in pressure drop compared to liquid nitrogen was a maximum of 40-50%. In the case of two different types of corrugated pipes with an inner diameter of either 12 mm or 15 mm, a pressure-drop reduction was confirmed at a flow velocity of over 2 m/s, and reached a maximum value of 37% at 30 wt.% compared to liquid nitrogen. The greater the solid fractions, the smaller the pipe friction factor became, and the pipe friction factor at the same solid fraction showed a constant value regardless of the Reynolds number. From the observation of the solid particles' behavior using a high-speed video camera and the PIV method, the pressure-drop reduction mechanisms for both C-D and corrugated pipes were demonstrated.

Ohira, Katsuhide; Okuyama, Jun; Nakagomi, Kei; Takahashi, Koichi

2012-12-01

53

Determination of the limiting stress-strain state of helically corrugated pipes  

Microsoft Academic Search

An approximate procedure for calculating the limiting stress-strain state (SSS) of helically corrugated pipes that operate under an axial force is developed. The calculation reduces to determination of the elastoplastic SSS of a shell of revolution with a circular corrugation, which is under axial and torsional loads. The problem is solved using the geometrically nonlinear theory of shells in a

Yu. N. Shevchenko; V. A. Merzlyakov; A. Z. Galishin; S. V. Novikov; P. S. Yukhimets

1993-01-01

54

Brinkman equation for a corrugated pipe using a spectral-Galerkin method  

Microsoft Academic Search

This study numerically investigates the fully developed flow of a Newtonian fluid in a porous-saturated corrugated pipe, on the basis of a Brinkman model. The variable coefficient Helmholtz equation, which is obtained by means of an epitrochoid transformation, is solved using a spectral–Galerkin method. The effects of both the Darcy number and corrugation on the velocity field are discussed and

F. Talay Akyildiz; Hamid Bellout

2010-01-01

55

Surface impedance formalism for a metallic beam pipe with small corrugations  

NASA Astrophysics Data System (ADS)

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 ? and magnetic permeability ?. 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. They are also shown to be more accurate when compared to the earlier used analytical model.

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

2012-12-01

56

Whistling behavior of periodic systems: Corrugated pipes and multiple side branch system  

Microsoft Academic Search

Whistling behavior of two geometrically periodic systems are investigated: corrugated pipes and a multiple side branch system. In both systems frequency (Helmholtz number) is a non-decreasing piecewise constant function of the Mach number, whose increase on average is approximately linear. The plateaus, lock-in frequencies, of this piecewise constant function correspond to the longitudinal acoustic pipe modes. In both systems pressure

Güne? Nakibo?lu; Stefan P. C. Belfroid; Johannes F. H. Willems; Avraham Hirschberg

2010-01-01

57

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

58

Friction Factors for Hydraulic Design of Corrugated Metal Pipe.  

National Technical Information Service (NTIS)

This paper is based on the results of a research project initiated in 1958 and sponsored jointly by the Bureau of Public Roads and the Office, Chief of Engineers, for the purpose of determining resistance coefficients of structural plate corrugated metal ...

J. L. Grace

1965-01-01

59

Investigation of the Cooling of Two-Layer Corrugated Polymeric Pipes  

NASA Astrophysics Data System (ADS)

Physical and mathematical models of the one-side and two-side cooling of two-layer corrugated polymeric pipes in the process of their production by coextrusion are considered. The models proposed allow one to determine the rational regimes of work of the coolers used in a line for production of such pipes, providing a required output of this line. Results of a mathematical simulation of the one-side and two-side cooling of the indicated pipes are presented. The results of calculations were compared with the corresponding experimental data.

Voznyuk, V. T.; Karvatskii, A. Ya.; Mikulenok, I. O.

2013-05-01

60

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

Microsoft Academic Search

It is well known that an air flow in a corrugated pipe might excite the longitudinal acoustic modes of the pipe. In this letter is reported experiments where a low frequency, oscillating flow with velocity magnitudes of the same order as the air flow has been added. Depending on the oscillation strength, it might silence the pipe or move the

Ulf R. Kristiansen; Pierre-Olivier Mattei; Cédric Pinhède; Muriel Amielh

2010-01-01

61

Experiments on the influence of low frequency sound on the acoustic resonances in a corrugated flow pipe  

Microsoft Academic Search

It is well known that an air flow in a corrugated pipe might excite the\\u000alongitudinal acoustic modes of the pipe. In this letter is reported experiments\\u000awhere a low frequency, oscillating flow with velocity magnitudes of the same\\u000aorder as the air flow has been added. Depending on the oscillation strength, it\\u000amight silence the pipe or move the

Ulf R. Kristiansen; Pierre-Olivier Mattei; Cédric Pinhède; Muriel Amielh

2010-01-01

62

Finite element analysis of guided waves in fluid-filled corrugated pipes.  

PubMed

Free wave propagation in fluid-filled corrugated pipes is analyzed using finite element methods in combination with a wave-based approach. By combining discretized models with a wave-based approach, complex mechanism of wave motion in the three-dimensional waveguide is fully included. The pipes are treated as waveguides having periodic properties in the direction of wave propagation. The analysis of these guided waves leads to dispersion curves which show the strong frequency-dependency of the different wave modes. The method also allows the inclusion of coupling between fluid-borne and structure-borne wave modes which occur at the acoustic-structure interface. Phase and group velocities of the wave modes are derived in postprocessing steps. Additionally, the energy ratio of the fluid-domain and solid-domain vibrational energies is computed. Finally, linear damping models are included in order to explore wave mode attenuation. PMID:17407866

Maess, Matthias; Herrmann, Jan; Gaul, Lothar

2007-03-01

63

OPTIMIZATION OF HYDROFORMING PROCESS FOR MANUFACTURING OF STAINLESS STEEL CORRUGATED FLEXIBLE HOSE PIPE USING THE TAGUCHI METHOD  

Microsoft Academic Search

This paper presents a study in which the Taguchi method, a powerful tool to design and process optimization for quality, is used to determine the optimal parameters of hydroforming process that is used to produce stainless steel corrugated flexible hose pipes. An orthogonal array, the signal-to-noise (S\\/N) ratio, and analysis of variance (ANOVA) are employed to investigate the process parameters

Abdullah O. Bafail; Sheikh I. Ishrat; Zahid A. Khan

2007-01-01

64

Pump effect of an electrical vortex flow in a corrugated pipe  

Microsoft Academic Search

The main result of this experimental and theoretical investigation was the discovery of a pump effect of the electrical vortex flow in a channel with insulated asymmetrically corrugated walls. It was established that the pressure of the liquid is created in the direction established above: sudden expansion-gradual contraction of the channel. The pressure, with a high degree of accuracy, linearly

R. Suleimanov; Y. Freiberg

1986-01-01

65

24. WEST CONFEDERATE AVENUE, DOUBLE CULVERT APPEARS TO BE "BOX", ...  

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

24. WEST CONFEDERATE AVENUE, DOUBLE CULVERT APPEARS TO BE "BOX", BUT IS PIPE WITH SQUARE HEAD WALL OPENING. NOTE ARCHED TOP STYLE USED BY CCC. VIEW SE. - Gettysburg National Military Park Tour Roads, Gettysburg, Adams County, PA

66

Pump effect of an electrical vortex flow in a corrugated pipe  

SciTech Connect

The main result of this experimental and theoretical investigation was the discovery of a pump effect of the electrical vortex flow in a channel with insulated asymmetrically corrugated walls. It was established that the pressure of the liquid is created in the direction established above: sudden expansion-gradual contraction of the channel. The pressure, with a high degree of accuracy, linearly increases along the channel length, which indicates the smallness of end and other secondary effects. The dependence of the average pressure gradient on the square of the current has a linear character.

Suleimanov, R.; Freiberg, Y.

1986-04-01

67

Friction factor estimation for turbulent flows in corrugated pipes with rough walls  

Microsoft Academic Search

The motivation of the investigation is critical pressure loss in cryogenic flexible hoses used for LNG transport in offshore installations. Our main goal is to estimate the friction factor for the turbulent flow in this type of pipes. For this purpose, two- equation turbulence models (k e and k w) are used in the computations. First, fully developed turbulent flow

Maxim Pisarenco; Bas van der Linden; Arris Tijsseling; Emmanuel Ory; Jacques Dam

2009-01-01

68

Instrumentation for the Apple Canyon Culvert.  

National Technical Information Service (NTIS)

The project covers the instrumenting of a culvert installation to acquire test data for culverts under high fills. The information is desired to answer the question of the adequacy of present culvert design formulas when used under high fills. The culvert...

W. Chow W. Weber

1966-01-01

69

Detrimental Effects of Natural Soil and Water Elements on Drainage Pipe Structures in Alabama.  

National Technical Information Service (NTIS)

Field studies were conducted in Alabama on soil and water parameters to determine their relationship to culvert pipe corrosion. The types of culvert materials investigated included concrete, galvanized steel, bituminous-coated galvanized steel, aluminum, ...

L. W. Hyde V. M. Shamburger J. S. Ellard R. E. Pate

1969-01-01

70

Culverts and Pipelines: Design, Monitoring, Evaluation, and Repair, 1991.  

National Technical Information Service (NTIS)

Contents: Impact Effects on Pipelines Beneath Railroads; Evaluation of Flexible Culvert Behavior; Evaluation of Shear Plates and Grouted Shear Key Joint Performance of a Three-Sided Precast Culvert; Microcomputer-Based Culvert Ranking System; Economic Con...

N. C. Kassabian A. G. Tobias L. Crayton N. Solomon

1991-01-01

71

Development of advanced design, insulation, and installation practices for hot water district heating piping  

Microsoft Academic Search

In the first part of this paper, some of the newest design features of hot water district heating piping are described. Emphasis is on polyurethane preinsulated one- and two-pipe elements equipped with a polyethylene jacket pipe. The paper also deals with the newest developments in concrete culvert district heating lines, namely the preinsulated concrete culvert pipe elements with a metal

Huovilainen

1983-01-01

72

DRA-8. Friction reduction in corrugated tubes.  

National Technical Information Service (NTIS)

The effect of wall roughness on friction reduction with micellar additives has been studied using Habon-G or Dobon-G as additive and three corrugated pipes as model rough-walled pipes. The k(sub s)/D ratios that could be calculated for these three tubes a...

H. Bjurstroem J. Nilsson

1996-01-01

73

Design and Construction of Small Span Bridges and Culverts Using Controlled Low Strength Material (CLSM).  

National Technical Information Service (NTIS)

The report deals with research related to the use of a Controlled Low Strength Material (CLSM) as a backfill (Controlled Density Fill, CDF) around two flexible culverts as demonstration projects. The projects consisted of a pipe arch and a long span arch....

W. E. Brewer

1992-01-01

74

Lock Culvert Valves; Hydraulic Design Considerations.  

National Technical Information Service (NTIS)

This report presents a review of design guidance and hydraulic parameters associated with lock culvert valves. Many locks are beyond their design life, and the filling- and emptying-culvert valves are being replaced to keep the lock in service. Valve sele...

E. A. Hammack J. J. Hite R. L. Stockstill

2011-01-01

75

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...

76

Culvert Information Management System - Demonstration Project.  

National Technical Information Service (NTIS)

The overall objective of the research was to develop a pilot scale Culvert Information Management System (CIMS) that will comply with both requirements stipulated by the Governmental Accounting Standards Board (GASB-34) and new federal storm water regulat...

C. Tang J. N. Meegoda T. M. Juliano

2009-01-01

77

Improved design and construction of large-span culverts  

Microsoft Academic Search

A comprehensive review was made of the design and construction of flexible metal and rigid reinforced concrete large-span culverts, past documented field experience of monitored culvert performance, and culvert failures. Full-scale field testing of a flexible metal and a reinforced concrete large-span culvert was conducted and the results compared with finite element computer analyses. Based on this work recommendations for

Mark Cottington Webb

1999-01-01

78

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 aluminium 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 {minus}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 waveguides. 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, C.P.

1989-02-15

79

Dynamic test of a corrugated steel keyworker blast shelter MISTY PICTURE. Final report  

Microsoft Academic Search

The 18-man blast shelter was tested dynamically on May 14, 1987 in the MISTY PICTURE event at White Sands Missile Range, NM. The main section of the shelter was fabricated from a 9-foot-diameter, 27.5-foot-long section of 10-gage, galvanized, corrugated steel culvert. The shelter included a vertical entryway and air intake and exhaust stacks. The shelter design was found to be

R. L. Holmes; T. R. Slawson; A. L. Harris

1987-01-01

80

Detail view of culvert headwall (no feature number assigned), from ...  

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

Detail view of culvert headwall (no feature number assigned), from the south side, looking north, near the west end of the project area. Culvert is located approximately 2000 feet east of Feature 2 - Beartooth Highway, Red Lodge, Montana to Cooke City, Montana, Cody, Park County, WY

81

Detail view of culvert headwall (no feature number assigned), from ...  

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

Detail view of culvert headwall (no feature number assigned), from the south side, looking north, near the west end of the project area. Culvert is located approximately 1000 feet east of Feature 1 - Beartooth Highway, Red Lodge, Montana to Cooke City, Montana, Cody, Park County, WY

82

Fish Movement Ecology in High Gradient Headwater Streams: Its Relevance to Fish Passage Restoration through Stream Culvert Barriers  

USGS Publications Warehouse

Executive Summary Restoration of fish passage through culvert barriers has emerged as a major issue in the Pacific Northwest and nationwide. The problem has many dimensions, including the huge number of potential barriers, uncertainty about which structures are actually barriers, the benefits and risks involved with restoration, and the financial costs and timelines. This report attempts to address what we call 'thinking outside of the pipe' in terms of fish passage information needs. This means understanding the value of each potential passage restoration project in the context of other possible projects, and to view individual restoration projects within a larger landscape of habitats and population processes. In this report we provide a brief review of some essential characteristics of animal movement and examples from a focal group of fishes in Washington State: salmon, trout, and char. While several other fishes and many other species use streams where culvert passage barriers may occur, it is the salmonids that are by far the most widespread and in most cases extending furthest into the headwaters of stream networks in Washington. We begin this report by outlining some basic characteristics of animal movement and then apply that foundation to the case of salmonid fishes. Next we consider the consequences of disrupting fish movement with human-constructed barriers, such as culverts. Finally, this body of evidence is summarized and we propose a short list of what we view as high priority information needs to support more effective restoration of fish passage through culverts.

Hoffman, Robert L.; Dunham, Jason

2007-01-01

83

Impedance of a rectangular beam tube with small corrugations  

NASA Astrophysics Data System (ADS)

We consider the impedance of a structure with rectangular, periodic corrugations on two opposing sides of a rectangular beam tube. Using the method of field matching, we find the modes in such a structure. We then limit ourselves to the case of small corrugations, but where the depth of corrugation is not small compared to the period. For such a structure we generate analytical approximate solutions for the wave number k, group velocity vg, and loss factor ? for the lowest (the dominant) mode which, when compared with the results of the complete numerical solution, agreed well. We find if w˜a, where w is the beam pipe width and a is the beam pipe half-height, then one mode dominates the impedance, with k˜1/?(w?) (? is the depth of corrugation), (1-vg/c)˜?, and ?˜1/(aw), which (when replacing w by a) is the same scaling as was found for small corrugations in a round beam pipe. Our results disagree in an important way with a recent paper of Mostacci et al. [

A. Mostacci et al., Phys. Rev. ST Accel. Beams 5, 044401 (2002)
], where, for the rectangular structure, the authors obtained a synchronous mode with the same frequency k, but with ?˜?. Finally, we find that if w is large compared to a then many nearby modes contribute to the impedance, resulting in a wakefield that Landau damps.

Bane, K. L.; Stupakov, G.

2003-02-01

84

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

85

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

86

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

87

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

88

Detail view of Feature 1, culvert headwall, from the north ...  

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

Detail view of Feature 1, culvert headwall, from the north side, looking south, at the west end of the project area - Beartooth Highway, Red Lodge, Montana to Cooke City, Montana, Cody, Park County, WY

89

Detail view of Feature 2, culvert headwall, from the north ...  

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

Detail view of Feature 2, culvert headwall, from the north side, looking south, near the west end of the project area - Beartooth Highway, Red Lodge, Montana to Cooke City, Montana, Cody, Park County, WY

90

Detail view of Feature 3, culvert headwall, from the south ...  

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

Detail view of Feature 3, culvert headwall, from the south side, looking north, near the west end of the project area - Beartooth Highway, Red Lodge, Montana to Cooke City, Montana, Cody, Park County, WY

91

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

92

78. LOCKS CULVERT TAINTER VALVE CHAMBERS EAST AND ...  

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

78. LOCKS -- CULVERT TAINTER VALVE CHAMBERS -- EAST AND INTERMEDIATE WALLS -- MAIN LOCK M-L 27 20/33. Lock and Dam No. 27 - Upper Mississippi River 9-Foot Channel Project, Lock & Dam 27, Granite City, Madison County, IL

93

Fish Passage through Culverts in Montana: A Preliminary Investigation.  

National Technical Information Service (NTIS)

The objective of the report is to combine, in one document, previously reported information on factors influencing fish passage through culverts, especially as it pertains to conditions indicative of Montana. First, the need for considering fish passage i...

T. N. Tillinger O. R. Stein

1996-01-01

94

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

95

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

96

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

97

Construction and Long-Term Monitoring of a Concrete Box Culvert Bridge Reinforced with GFRP Bars.  

National Technical Information Service (NTIS)

This report presents the design, construction, and laboratory/field testing of a box culvert bridge reinforced with glass FRP (GFRP) bars. The concrete box culvert units were designed for maximum loads determined in accordance with AASHTO design guideline...

T. Alkhrdaji A. Nanni

2001-01-01

98

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

Microsoft Academic Search

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

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

99

Re-Evaluation of Design Procedures for Non-Bridge-Size Culverts.  

National Technical Information Service (NTIS)

NYSDOT recently experienced significant failure of a culvert halfway through its expected design life, raising questions as to whether the Department's design policy provides adequate strength and durability to ensure that culverts reach the limits of the...

M. Mathioudakis A. Agarwal

1996-01-01

100

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

Microsoft Academic Search

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

Ali Abolmaali; Anil Garg

2009-01-01

101

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

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

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

102

DETAIL OF WING WALL ON OUTLET SIDE OF CULVERT. NOTE ...  

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

DETAIL OF WING WALL ON OUTLET SIDE OF CULVERT. NOTE THE INCLUSIONS IN THE CONCRETE. OBLIQUE VIEW TO THE SOUTH-SOUTHWEST. 21 - Burlington Northern Santa Fe Railroad, Cajon Subdivision , Structure 58.1X, Between Cajon Summit and Keenbrook, Devore, San Bernardino County, CA

103

Fish Passage in Montana Culverts. Phase II. Passage Goals.  

National Technical Information Service (NTIS)

The primary objective of this study is to determine the rate and timing of fish passage in culverts that is desirable for species diversity maintenance. For Montana resident trout species, there appears to be conservatism in fish passage indicators that i...

A. Solcz J. E. Cahoon M. Blank O. Stein T. McMahon

2007-01-01

104

Mass transfer in corrugated membranes  

NASA Astrophysics Data System (ADS)

Research on the chemical and physical structure of membranes has failed to overcome the inverse relationship between selectivity and permeability. While this permeability is partially responsible for the rate of separation, the geometry of the membrane contributes significantly to this rate. In this work, we focused on the system geometry by examining the effect of corrugations on the rate of membrane separations. We developed a theory to describe mass transport in corrugations and to predict the effectiveness of corrugated membranes. To verify this theory, membranes with millimeter-sized corrugations were made. Pervaporation experiments with highly permeable and less permeable solutes showed excellent agreement with the theory. Based on the membrane geometry and permeability, the effectiveness factor and the flux enhancement can be quantified by a modified Thiele analysis. We used this theory to examine the effect of small corrugations on the mass transfer of both liquids and gases across membranes, including the effects of free convection, membrane supports, and Knudsen diffusion. In systems with a liquid feed, corrugations are promising only for very impermeable solutes. In gases, corrugations are more effective, especially when supported by a porous structure. We attempted to make smaller corrugations in two ways. The more promising method is phase-inversion of diblock copolymers. These diblocks were dissolved in a solvent, made into a thin film, and immersed in a liquid that was a nonsolvent for the majority block and a solvent for the minority block. In this way, we attempted to draw the minority block to the surface of an undulating structure created by the phase inversion. Ideally, the minority block would be selective and the majority block would be highly permeable or porous. Scanning electron microscopy showed promising structures made from polystyrene-polyisoprene and polyacrylonitrile-polyethylene oxide. The other, less promising, attempt at making high surface area membranes used interfacial polymerization across a surfactant-templated interface. This surfactant template, which offers enhanced surface area, occurs in the bicontinuous surfactant-rich phase of a three-phase system. The permeability of control membranes made by typical interfacial polymerization was compared with the permeability of membranes made in microemulsions. The latter were compromised by defects.

Gronda, Ann Mclaughry

105

Shear correction factors for corrugated core structures  

Microsoft Academic Search

Because of the high computational cost involved when modeling a corrugated panel (in e.g., finite element analyses) the corrugated core sandwich is in this investigation homogenized and the panel is transformed to an equivalent continuous homogenous layer with effective equal properties. Mathematically, the corrugated board panel is divided into an arbitrary number of thin virtual layers. For each virtual layer,

P. Isaksson; A. Krusper; P. A. Gradin

2007-01-01

106

LONG-SPAN GUARDRAIL SYSTEM FOR CULVERT APPLICATIONS  

Microsoft Academic Search

A long-span guardrail for use over low-fill culverts was developed and successfully crash tested. The guardrail system was configured with 30.48 m of nested, 12-gauge W-beam rail and centered around a 7.62-m-long unsupported span. The nested W-beam rail was supported by 16 W152 x 13.4 steel posts and 6 standard CRT posts, each with two 150-mm x 200 x 360

Ronald K Faller; Dean L Sicking; Karla A Polivka; John R Rohde; Bob W Bielenberg

2000-01-01

107

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

Microsoft Academic Search

A two-phase closed thermosiphon made of a corrugated tube was developed to extend the application field of heat pipes. In the first paper, the thermal performance of the evaporator section was examined with the thermosiphons set vertical or tilted. The paper describes the thermal performance of the condenser section. A condensation heat-transfer coefficient is proposed as a function of Nusselt's

M. Hirashima; Y. Nishikawa; M. Taguchi; K. Negishi; K. Kaneko; T. Matsuoka

1991-01-01

108

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

109

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

110

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

111

Instability in pipe flow  

PubMed Central

The long-puzzling, unphysical result that linear stability analyses lead to no transition in pipe flow, even at infinite Reynolds number, is ascribed to the use of stick boundary conditions, because they ignore the amplitude variations associated with the roughness of the wall. Once that length scale is introduced (here, crudely, through a corrugated pipe), linear stability analyses lead to stable vortex formation at low Reynolds number above a finite amplitude of the corrugation and unsteady flow at a higher Reynolds number, where indications are that the vortex dislodges. Remarkably, extrapolation to infinite Reynolds number of both of these transitions leads to a finite and nearly identical value of the amplitude, implying that below this amplitude, the vortex cannot form because the wall is too smooth and, hence, stick boundary results prevail.

Cotrell, D. L.; McFadden, G. B.; Alder, B. J.

2008-01-01

112

Instability in pipe flow.  

PubMed

The long-puzzling, unphysical result that linear stability analyses lead to no transition in pipe flow, even at infinite Reynolds number, is ascribed to the use of stick boundary conditions, because they ignore the amplitude variations associated with the roughness of the wall. Once that length scale is introduced (here, crudely, through a corrugated pipe), linear stability analyses lead to stable vortex formation at low Reynolds number above a finite amplitude of the corrugation and unsteady flow at a higher Reynolds number, where indications are that the vortex dislodges. Remarkably, extrapolation to infinite Reynolds number of both of these transitions leads to a finite and nearly identical value of the amplitude, implying that below this amplitude, the vortex cannot form because the wall is too smooth and, hence, stick boundary results prevail. PMID:18178623

Cotrell, D L; McFadden, G B; Alder, B J

2008-01-04

113

Finite-Element Modeling and Analysis of Reinforced Concrete Box Culverts  

Microsoft Academic Search

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

Anil K. Garg; Ali Abolmaali

2009-01-01

114

Durability investigation of concrete culverts reinforced with steel and glass fiber reinforced polymer by acoustic emission  

Microsoft Academic Search

This dissertation presents a methodology to comparatively evaluate the durability of concrete culverts reinforced with traditional steel rebars and culverts reinforced with GFRP using the acoustic emission (AE) technology. GFRP seems promising as compared to steel rebars as they are not expected to corrode in harsh environments. However, in conventional structures use of GFRP as reinforcement is not usually desired

Recep Birgul

2001-01-01

115

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

116

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...

117

High resolution gamma-ray spectrometry of culverts containing transuranic waste at the Savannah River Site  

SciTech Connect

A number of concrete culverts used to retrievably store drummed, dry, radioactive waste at the Savannah River Site (SRS), were suspected of containing ambiguous quantities of transuranic (TRU) nuclides. These culverts were assayed in place for Pu-239 content using thermal and fast neutron counting techniques. High resolution gamma-ray spectroscopy on 17 culverts, having neutron emission rates several times higher than expected, showed characteristic gamma-ray signatures of neutron emitters other than Pu-239 (e.g., Pu-238, Pu/Be, or Am/Be neutron sources). This study confirmed the Pu-239 content of the culverts with anomalous neutron rates and established limits on the Pu-239 mass in each of the 17 suspect culverts by in-field, non-intrusive gamma-ray measurements.

Hofstetter, K.J.; Sigg, R.

1990-12-31

118

High resolution gamma-ray spectrometry of culverts containing transuranic waste at the Savannah River Site  

SciTech Connect

A number of concrete culverts used to retrievably store drummed, dry, radioactive waste at the Savannah River Site (SRS), were suspected of containing ambiguous quantities of transuranic (TRU) nuclides. These culverts were assayed in place for Pu-239 content using thermal and fast neutron counting techniques. High resolution gamma-ray spectroscopy on 17 culverts, having neutron emission rates several times higher than expected, showed characteristic gamma-ray signatures of neutron emitters other than Pu-239 (e.g., Pu-238, Pu/Be, or Am/Be neutron sources). This study confirmed the Pu-239 content of the culverts with anomalous neutron rates and established limits on the Pu-239 mass in each of the 17 suspect culverts by in-field, non-intrusive gamma-ray measurements.

Hofstetter, K.J.; Sigg, R.

1990-01-01

119

A Parametric Study of Cut-off Corrugated Surface Properties.  

National Technical Information Service (NTIS)

Corrugated horns involve a junction between the corrugated surface and a conducting groundplane. Proper horn design requires an understanding of the electromagnetic properties of the corrugated surface and this junction. Therefore, an integral equation so...

C. A. Mentzer L. Peters

1973-01-01

120

Bending behaviour of corrugated web beams  

Microsoft Academic Search

The paper is devoted to the behaviour of mild steel structural beams with corrugated web subjected to three-point bending. Semicircular web corrugation in the cross-sectional plane (horizontal) and across the span of the beam (vertical) were investigated both experimental and computationally using finite element technique. In the finite element analysis, test specimen was modelled using commercially available finite element software

Y. A Khalid; C. L Chan; B. B Sahari; A. M. S Hamouda

2004-01-01

121

Effect of sleeper distance on rail corrugation  

Microsoft Academic Search

The present paper looks at the effect of sleeper separation on rail corrugation growth. The case under study involves short pitch corrugations on the low rail in sharp bends, the bends in question being those of metro-type railways in Bilbao, with the track on concrete slabs and with two resilient stages of STEDEF type. With an initial sleeper separation of

Ernesto García Vadillo; José A. Tárrago; Gorka Garate Zubiaurre; Carlos Angulo Duque

1998-01-01

122

On the theory of corrugated plane surfaces  

Microsoft Academic Search

An analysis is given of an electromagnetic system composed of a rectangular waveguide in tandem with a corrugated waveguide which feeds a flat, corrugated surface of arbitrary length terminated by a ground plane, whose length is also arbitrary. An improved procedure of field determination is used which combines Floquet's theorem and the variational principle, thus revealing an additional requirement on

R. Elliott

1954-01-01

123

Bioinspired Corrugated Airfoil at Low Reynolds Numbers  

Microsoft Academic Search

An experimental study was conducted to investigate the flow behavior around a bioinspired corrugated airfoil compared with a traditional streamlined airfoil and a flat plate at the chord Reynolds number of Re 34; 000 to explore the potential application of such bioinspired corrugated airfoils for micro air vehicle applications. The experiments were conducted in a low-speed wind tunnel. A high-resolution

Hui Hu; Masatoshi Tamai

2008-01-01

124

Basic measurements on a multiple heat pipe  

NASA Astrophysics Data System (ADS)

A multiple heat pipe which is a specially formed long heat pipe that fulfills the function of several single heat pipes was studied. The suitability of this arrangement for a heat exchanger was investigated. Several laboratory models were manufactured from corrugated tubes and their behavior was measured. Results show that the serpentine model exhibits the expected heat exchange properties. When subjected to severe operating conditions, the pipes remain operational, although somewhat limited in performance. The results are in function of the nature of the exchange media (air-air, air-water, water-water). This corrugated heat pipe design shows good promise for successful further development into an air-air heat exchanger.

Rohner, P.; Schippl, K.

1982-04-01

125

Comparison of the Impacts of Culverts versus Bridges on Stream Habitat and Aquatic Fauna.  

National Technical Information Service (NTIS)

This project was an interdisciplinary look at the differences in impacts between culverts and bridges on stream habitat and stream fauna. There were four essential components: (1) Freshwater mussels: We took habitat measurements and conducted mussel surve...

A. E. Bogan C. B. Eads D. Eggleston D. Shea J. Gregory J. F. Levine J. V. Pluym L. F. Humphries M. A. Merril P. R. Lazaro R. B. Bringolf W. G. Cope

2007-01-01

126

PVA Fiber Reinforced Shotcrete for Rehabilitation and Preventative Maintenance of Aging Culverts.  

National Technical Information Service (NTIS)

The goal of this project was to investigate the potential for using PVA (polyvinyl alcohol) fiber reinforced mortar for the rehabilitation and preventative maintenance of aging metal highway drainage culverts using a spray-on liner application approach. T...

B. Pillay B. Thattaiparthasarat J. Kang J. S. Davidson U. K. Vaidya

2008-01-01

127

Fundamentals of Culvert Design for Passage of Weak-Swimming Fish.  

National Technical Information Service (NTIS)

Properly designed culverts do not produce water velocities that exceed fish swimming abilities. Fish have two different musculature systems for swimming. A white muscle system generates power for short vigorous swimming. A red muscle system furnishes powe...

C. E. Behlke D. L. Kane R. F. McLean M. D. Travis

1991-01-01

128

Modernization of the Kadomtsev corrugated trap  

SciTech Connect

Various modifications of the Kadomtsev corrugated trap intended for model experiments on studying turbulent plasma dynamics are discussed. The possibility of using the existing magnetic system of the TO-2 tokamak for this purpose is considered as an example.

Dlugach, E. D.; Mikhailova, N. A.; Skovoroda, A. A. [National Research Centre Kurchatov Institute (Russian Federation)

2011-10-15

129

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

130

Approximate Method for Computing Backwater Profiles in Corrugated Metal Pipes.  

National Technical Information Service (NTIS)

The determination of the shape and characteristics of a backwater profile in a closed conduit is generally a lengthy and tedious procedure without the use of a computer. By using the charts and tables of this publication and a few simple calculations, it ...

P. N. Zelensky

1976-01-01

131

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

132

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

Code of Federal Regulations, 2010 CFR

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

2011-10-01

133

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

Code of Federal Regulations, 2010 CFR

...2006-10-01 2006-10-01 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...

2006-10-01

134

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

Code of Federal Regulations, 2010 CFR

...2012-10-01 2012-10-01 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...

2012-10-01

135

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

Code of Federal Regulations, 2010 CFR

...2008-10-01 2008-10-01 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...

2008-10-01

136

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

137

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

Code of Federal Regulations, 2010 CFR

...2007-10-01 2007-10-01 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...

2007-10-01

138

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

Code of Federal Regulations, 2010 CFR

...2009-10-01 2009-10-01 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...

2009-10-01

139

Dynamic test of a corrugated steel keyworker blast shelter MISTY PICTURE. Final report  

SciTech Connect

The 18-man blast shelter was tested dynamically on May 14, 1987 in the MISTY PICTURE event at White Sands Missile Range, NM. The main section of the shelter was fabricated from a 9-foot-diameter, 27.5-foot-long section of 10-gage, galvanized, corrugated steel culvert. The shelter included a vertical entryway and air intake and exhaust stacks. The shelter design was found to be conservative during a previous 50-psi validation test, and some constructibility problems were encountered with the entryway-to-shelter connections. This test was conducted to validate the modifications made to the shelter design. The modifications were made to reduce construction costs and improve constructibility. Primary modifications included: replacing the stiffened endwalls with lighter-weight unstiffened plates, connecting the entryway to an endwall rather than to the main section of the shelter, and the inclusion of an emergency exit. The structure was located at the anticipated 200-psi peak overpressure level. Post-test inspection revealed that the main section of the shelter suffered very little damage during the test. Due to the failure of the emergency exit cover plate, it was necessary to determine if enough pressure entered the shelter to affect its structural response. This test also investigated the shock environment inside the shelter.

Holmes, R.L.; Slawson, T.R.; Harris, A.L.

1987-11-01

140

Elastic behavior of corrugated cardboard: experiments and modeling  

Microsoft Academic Search

Motivated by computed homogeneous of linear corrugated cardboard behavior, an analytical model related to the assessment of equals behavior is proposed. This model takes into account the geometrical and mechanical properties of the corrugated cardboard constituents. An experimental methodology is also proposed to obtain both the in-plane elastic properties of each constituents and the corrugated cardboard. After model validation by

Z. Aboura; N. Talbi; S. Allaoui; M. L. Benzeggagh

2004-01-01

141

Corrugator Supercilii Muscle Resection and Migraine Headaches  

Microsoft Academic Search

This study was conducted to determine whether there is an association between the removal of the corrugator supercilii muscle and the elimination or significant im- provement of migraine headaches. Questionnaires were sent to 314 consecutive patients who had undergone cor- rugator supercilii muscle resection during endoscopic, transpalpebral, or open forehead rejuvenation proce- dures. The patients were queried as to whether

Bahman Guyuron; Amin Varghai; Bryan J. Michelow; Theresa Thomas; Janine Davis

2000-01-01

142

Electron scattering on microscopic corrugations in graphene  

Microsoft Academic Search

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

M. I. Katsnelson; A. K. Geim

2008-01-01

143

Local buckling of composite corrugated compression panels  

Microsoft Academic Search

This paper investigates the problem of local instability of corrugated panels fabricated from composite materials and subjected to in-plane compressive loading. The panels are considered as a series of linked plate strips with rotationally restrained unloaded edges. At buckling, the moments and slopes at each common edge are related in such a way as to satisfy equilibrium and compatibility conditions.

M. N. Nahas

1993-01-01

144

Wave Propagation in Corrugated Plasma Slab.  

National Technical Information Service (NTIS)

Recently it has been shown that periodic corrugation of a cylindrical waveguide filled with a magnetized plasma results in drastic modification of the Trivelpiece-Gould (TG) modes: the spectrum turned out to be an infinitesimally fine grid, called a dense...

A. M. Ignatov

1994-01-01

145

Experimental investigation on discharge coefficient for a combined broad crested weir-box culvert structure  

NASA Astrophysics Data System (ADS)

We study flow over combined broad crested weir- box culvert structure.The discharge coefficient for combined structure is examined.12 Physical models were setup to examine the effect of structure characteristics.Discharge coefficient for each combined model increased compared to single models.

Guven, A.; Hassan, M.; Sabir, Shahin

2013-09-01

146

Automated Design and Plotting Programming for Three-Sided and Closed Type Culvert Structures. Phase 2.  

National Technical Information Service (NTIS)

The Phase II study was funded to upgrade the AutoCAD based 'Automated Design and Plotting (ADP) System for Three Sided and Closed Culvert Structures', completed in December 1994. The upgrade includes: (1) incorporating changes in plan sheet size and borde...

J. Jang

1999-01-01

147

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

NASA Astrophysics Data System (ADS)

As part of a biocomplexity project in Puerto Rico, we use river and road networks as a platform to understand the interactions between stream biota, the physical environment, and human activity. Specifically, we ask if humans affect aquatic organisms through road building and recreational activities. Culverts have been documented to impede or slow migration of aquatic biota. This is especially important in these streams because all of the freshwater, stream species have diadramous life cycles. If culverts do act as bottlenecks to shrimp migrations, we expect altered predator-prey interactions downstream through density-dependent predation dynamics. In order to determine how roads may affect predation rates on upstream migrating shrimp, we parameterized functional response curves for mountain mullet (Agonostomus monticola) consuming shrimp (Xiphocaris sp.) using artificial mesocosm experiments. We then used data obtained from underwater videography to determine how culverts decrease the rate and number of shrimp moving upstream. These data were combined in a predator-prey model to quantify the effects of culverts on localized shrimp densities and fish predation.

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

2005-05-01

148

On the validity of the British Columbia Forest Practices Code guidelines for stream culvert discharge design  

Microsoft Academic Search

In the stream culvert discharge design guidelines of the Forest Practices Code (FPC) of British Columbia (BC), the 100-year instantaneous flood (Q100) is assumed to be three times as large as the mean annual flood (Q2 )r e- gardless of basin characteristics and location in the province. A regional linear moment analysis of annual maximum flows is used to demonstrate

Jos Beckers; Younes Alila; Ahmed Mtiraoui

2002-01-01

149

Long term performance of polyethylene pipe under high fill. Part 2. Technical report, July 1990-June 1994  

SciTech Connect

The performance of a corrugated High Density Polyethylene (HDPE) pipe under high earth load was investigated. The cross-sectional shape of the pipes were essentially round after 5 years of burial. However, visual observations showed the development and growth of circumferential cracks in the unlined corrugated pipe and buckling of the unsupported portions of the liner in the smooth wall corrugated pipe. The cracks were mainly in the inside corrugation crests within the coupling length. The liner buckles were in the bottom half of the pipe. Material property tests on HDPE specimens cut from pieces of pipe showed the existence of longitudinal residual tensile stress in the pipe wall that were close to the yield stress of the HDPE. These residual stresses combined with longitudinal tensile stress induced by the coupling were probably the main cause of the crack development in the field. Laboratory tests were conducted on short lengths of pipe in ring bending and in hoop compression. The ring bending tests showed that the material modulus under short-term deflection increments does not diminish with time, whereas the apparent modulus under sustained deflection decreases with time. The hoop compression tests showed circumferential shortening, corrugation closure and liner buckling under external radial pressure consistent with the field observations.

Selig, E.T.

1995-06-01

150

Critical Instability and Friction Scaling of Fluid Flows through Pipes with Rough Inner Surfaces  

Microsoft Academic Search

It has been shown experimentally over nearly 80 years that surface fine roughness of circular pipes has a crucial effect on the natural transition to turbulence. In this Letter, a theoretical explanation is suggested for the roughness-induced instability. Once the nonlinear effect of roughness is introduced (through a pipe with fine corrugation surface), the mean velocity profile becomes unstable to

Jianjun Tao

2009-01-01

151

Generalization of experimental data on heat-transfer crisis in pipes  

NASA Astrophysics Data System (ADS)

The article presents generalized experimental data on heat-transfer crisis upon boiling in pipes with various types of intensifiers and without them, obtained by superposition of convective heat removal and mass transfer of liquid to the heating surface. For finned and corrugated pipes relationships are recommended that are suitable for use in calculations.

Sapankevich, A. P.

1983-06-01

152

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

153

A corrugated surface with low backscatter  

Microsoft Academic Search

A low backscatter corrugated metal surface has been designed, fabricated, and tested for H-polarized transverse electromagnetic (TEM) incident waves. The problem has been formulated using the scattering matrix approach and reflection and transmission co-efficients at the fin-air interface are determined using an integral equation approach. Hence, an expression for monostatic radar cross section (RCS) is obtained. The RCS has been

A. K. Bhattacharyya; S. K. Tandon

1984-01-01

154

Effective Thermal Conductivity of Corrugated Insulating Materials  

NASA Astrophysics Data System (ADS)

The measurement of the effective thermal conductivity of corrugated insulating materials, the evaluation of heat transfer mechanism in these materials and the improvement of insulating effect of them are studied in this paper. It is recognized that the contribution of radiative heat transfer to effective thermal conductivity is almost equal to the heat rate by conduction. The fairly good improvement are obtained by attaching Al foils to upper and lower surfaces of air space of specimen.

Yamada, Etsuro; Nishida, Yoshihiro; Takahashi, Kaneko; Ito, Hioshi; Shimada, Takeo

155

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

156

Effects of corrugation of the dragonfly wing on gliding performance.  

PubMed

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 degrees to 40 degrees . 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 coefficients. The flows such as vortex in the valley of corrugation and near the edge of the corrugation are locally different from those of an elliptic wing. However, such local flows have little influence on the time averaged wing performance. From the numerical experiment presented in this study, it is determined that suction side corrugations of the wing have very little influence on increase of the lift coefficient at a positive angle of attack. PMID:19631665

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

2009-07-23

157

Energy absorption diagrams of multi-layer corrugated boards  

Microsoft Academic Search

Based on the static compression experiments, the compressive stress-strain curve of multi-layer corrugated boards is simplified\\u000a into three sections of linear elasticity, sub-buckling going with local collapse and densification. By considering the structure\\u000a factors of multi-layer corrugated boards, the energy absorption model is obtained and characterized by the structure factors\\u000a of corrugated cell-wall. The model is standardized by the solid

Dongmei Wang

2010-01-01

158

The effects of construction on water quality: a case study of the culverting of Abram Creek  

Microsoft Academic Search

While sediment is a leading cause of impaired water, studies have shown that construction activities incorporating best management\\u000a practices (BMPs) can be conducted without lasting detrimental effects on water quality. This paper examines the water quality\\u000a impacts of a construction project involving the culverting of a creek to allow for the construction of a runway at an airport\\u000a in Cleveland,

Darci L. Houser; Heidi Pruess

2009-01-01

159

Wake fields effects due to surface roughness in a circular pipe  

NASA Astrophysics Data System (ADS)

The problem of the wake field generated by a relativistic particle travelling in a long beam pipe with rough surface has been revisited by means of a standard theory based on the hybrid modes excited in a periodically corrugated waveguide with circular cross section. Slow waves synchronous with the particle can be excited in the structure, producing wake fields whose frequency and amplitude depend on the depth of the corrugation. .

Angelici, M.; Frezza, F.; Mostacci, A.; Palumbo, L.

2001-08-01

160

Wake fields effects due to surface roughness in a circular pipe  

NASA Astrophysics Data System (ADS)

The problem of the wake field generated by a relativistic particle travelling in a long beam pipe with rough surface has been studied by means of a standard theory based on the hybrid modes excited in a periodically corrugated waveguide with circular cross-section. Slow waves synchronous with the particle can be excited in the structure, producing wake fields whose frequency and amplitude depend on the depth of the corrugation. An analytical expression of the wake field is given for very small corrugations.

Angelici, M.; Frezza, F.; Mostacci, A.; Palumbo, L.

2002-08-01

161

Unbiased diffusion in tubes with corrugated walls  

NASA Astrophysics Data System (ADS)

This study is devoted to unbiased motion of a point Brownian particle in a tube with corrugated walls made of conical sections of a varying length. Effective one-dimensional description in terms of the generalized Fick-Jacobs equation is used to derive a formula which gives the effective diffusion coefficient of the particle as a function of the geometric parameters of the tube. Comparison with the results of Brownian dynamics simulations allows us to establish the domain of applicability of both the one-dimensional description and the formula for the effective diffusion coefficient.

Dagdug, Leonardo; Vazquez, Marco-Vinicio; Berezhkovskii, Alexander M.; Bezrukov, Sergey M.

2010-07-01

162

Coaxial waveguide diplexing circuit using a corrugated waveguide transition  

Microsoft Academic Search

A technique using corrugated-wall waveguide to separate the energy from two frequency bands into concentric coaxially disposed circular waveguides is discussed. The corrugation depth is chosen so that the reactance sign of the surface impedance changes between the two frequency bands. This has the effect of matching the respective field distributions fo the coaxially disposed waveguides. A unique low-pass filter

R. W. Gruner

1987-01-01

163

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

164

Competition and Co-operation in the Corrugated Paper Industry  

Microsoft Academic Search

This paper describes how the five Swedish corrugated box manufacturers, while still in fierce competition, got together in 1999 to fight a new logistic system, plastic crates, which threatened to overtake a substantial part of the Swedish market for transport packaging. It explains the background of SWIF 2000, the competitive response by the five Swedish corrugated box manufacturers, how the

Carl-Henric Nilsson; Johan Axelson; Martin Emanuelsson

165

Horn Antenna Having V-Shaped Corrugated Slots.  

National Technical Information Service (NTIS)

The development of a corrugated horn antenna in which the corrugated surfaces of the antenna are formed by V-shaped slots was reported. The depth of the slots is between 0.3125 and 0.625 wavelengths. For this range of depths the surface impedance is capac...

C. A. Mentzer L. Peters

1974-01-01

166

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

167

A corrugated horn and circularly polarized feed system.  

NASA Astrophysics Data System (ADS)

This paper describes a wide-angle corrugated horn and circularly polarized feed system for use in reflector antennas. The new corrugated horn feeder is investigated theoretically and its practical engineering design is given. Experimented results show that near-perfect pattern symmetry is achieved in the fee system.

Yin, Xinghui

1995-12-01

168

Water absorption in horizontal corrugated boards under water sprays  

Microsoft Academic Search

Experiments were performed to determine the water absorption propensity of four different corrugated boards oriented horizontally and exposed to vertical water sprays from above. The corrugated samples used in the experiments were taken from cartons and partition boards from the FM Global Standard Plastic Commodity and from the inner and outer cartons of the FM Global Class II Commodity. These

T. M. Jayaweera; H.-Z. Yu

2006-01-01

169

Coaxial cavities with corrugated inner conductor for gyrotrons  

Microsoft Academic Search

This paper investigates coaxial gyrotron cavities with longitudinal slots on the inner conductor as a means to reduce the number of possible competing modes. In the analytic theory the corrugated surface is treated as a homogeneous impedance surface (“impedance corrugation”) to obtain simple formulas for the characteristic equation of the eigenmodes, for the electromagnetic fields and the wall losses. The

Christos T. Iatrou; S. Kern; Alexander B. Pavelyev

1996-01-01

170

Scalar Casimir-Polder forces for uniaxial corrugations  

SciTech Connect

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.

Doebrich, Babette [Theoretisch-Physikalisches Institut, Friedrich-Schiller-Universitaet Jena, Max-Wien-Platz 1, D-07743 Jena (Germany); Institut fuer Theoretische Physik, Universitaet Heidelberg, Philosophenweg 16, D-69120 Heidelberg (Germany); Physikalisches Institut, Universitaet Heidelberg, Philosophenweg 12, D-69120 Heidelberg (Germany); DeKieviet, Maarten [Physikalisches Institut, Universitaet Heidelberg, Philosophenweg 12, D-69120 Heidelberg (Germany); Gies, Holger [Theoretisch-Physikalisches Institut, Friedrich-Schiller-Universitaet Jena, Max-Wien-Platz 1, D-07743 Jena (Germany); Institut fuer Theoretische Physik, Universitaet Heidelberg, Philosophenweg 16, D-69120 Heidelberg (Germany)

2008-12-15

171

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

172

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

173

Composite corrugated structures for morphing wing skin applications  

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

174

Pipe support  

DOEpatents

A pipe support for high temperature, thin-walled piping runs such as those used in nuclear systems. A section of the pipe to be supported is encircled by a tubular inner member comprised of two walls with an annular space therebetween. Compacted load-bearing thermal insulation is encapsulated within the annular space, and the inner member is clamped to the pipe by a constant clamping force split-ring clamp. The clamp may be connected to pipe hangers which provide desired support for the pipe.

Pollono, Louis P. (Hempfield Township, Hempfield County, PA)

1979-01-01

175

Fatigue testing of corrugated and Teflon hoses  

NASA Astrophysics Data System (ADS)

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.

176

Iron line variability of discoseismic corrugation modes  

NASA Astrophysics Data System (ADS)

Using a fast semi-analytic raytracing code, we study the variability of relativistically broadened Fe-K? lines due to discoseismic oscillations concentrated in the innermost regions of accretion discs around black holes. The corrugation mode, or c-mode, is of particular interest as its natural frequency corresponds well to the ˜0.1-15 Hz range observed for low-frequency quasi-periodic oscillations (LFQPOs) for lower spins. Comparison of the oscillation phase dependent variability and quasi-periodic oscillation-phase stacked Fe-K? line observations will allow such discoseismic models to be confirmed or ruled out as a source of particular LFQPOs. The spectral range and frequency of the variability of the Fe-K? line due to c-modes can also potentially be used to constrain the black hole spin if observed with sufficient temporal and spectral resolution.

Tsang, David; Butsky, Iryna

2013-10-01

177

Analysis of stiffened corrugated plates based on the FSDT via the mesh-free method  

Microsoft Academic Search

The elastic bending of unstiffened and stiffened corrugated plates is studied in this paper, and a mesh-free Galerkin method is presented for the analyses. A corrugated plate is treated as an orthotropic plate that has different flexure properties in two perpendicular directions. The equivalent flexure properties are estimated by applying constant curvature conditions to the corrugated sheet. The stiffened corrugated

L. X. Peng; K. M. Liew; S. Kitipornchai

2007-01-01

178

Thermal stability of corrugated epitaxial graphene grown on Re(0001).  

PubMed

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. PMID:21699318

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

2011-05-25

179

Plasma outflow from a corrugated trap in the kinetic regime  

SciTech Connect

The problem of stationary plasma outflow from an open corrugated trap in the kinetic regime is considered with allowance for pair collisions in the framework of a kinetic equation with the Landau collision integral. The distribution function is studied in the limit of small-scale corrugation and a large mirror ratio. In considering a single corrugation cell, a correction for the distribution function is calculated analytically. An equation describing variations of the distribution function along the system is derived and used to study the problem of plasma outflow into vacuum.

Skovorodin, D. I.; Beklemishev, A. D. [Russian Academy of Sciences, Budker Institute of Nuclear Physics, Siberian Branch (Russian Federation)

2012-03-15

180

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

181

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

182

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

183

Method of Making an Offset Corrugated Sandwich Construction.  

National Technical Information Service (NTIS)

A method for making an offset corrugated core sandwich construction is disclosed. Mandrels of preestablished form and size are arranged into a pattern in a confined area. After covering the mandrels with a release film, strips of pliable, uncured composit...

H. Ray L. W. Gause

1993-01-01

184

Decay of Molecules at Corrugated Thin Metal Films.  

National Technical Information Service (NTIS)

The problem of the decay rate for molecules at corrugated thin metal films is considered theoretically via a classical phenomenological approach by generalizing a previous theory for a single rough surface. In particular, numerical results are worked out ...

P. T. Leung T. F. George Y. S. Kim

1989-01-01

185

Determination of the surface corrugation amplitude from classical atom scattering.  

PubMed

The energy landscape of an atomic or molecular projectile interacting with a surface is often described in terms of a corrugation function that gives the classical turning point as a function of position vector parallel to the surface. It is shown here that the relative height variation of the corrugation function for scattering of atoms under classical conditions can be determined by a measurement of the maximum intensity in energy-resolved scattering spectra as a function of surface temperature. This is demonstrated by developing a semiclassical quantum theory of atomic scattering from corrugated surfaces and then extending the theory to the classical limit of large incident energies and high surface temperatures. Comparisons of calculations with available data for Ar atom scattering determine the corrugation amplitude for a molten In surface to be about 29% of the mean interparticle spacing in the bulk liquid. PMID:23006264

Hayes, W W; Manson, J R

2012-08-10

186

1. Elkmont vehicle bridge at Elkmont Campground, galvanized corrugated arch. ...  

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

1. Elkmont vehicle bridge at Elkmont Campground, galvanized corrugated arch. - Great Smoky Mountains National Park Roads & Bridges, Elkmont Vehicle Bridge, Spanning Little River at Elkmont Campground, Gatlinburg, Sevier County, TN

187

Hydrodynamics of Gas-Liquid Counterflow Through Corrugated Parallel Plates  

SciTech Connect

Structured packings utilized in today's distillation packed towers consist of stacked units of many vertically oriented parallel corrugated plates. The V-shaped corrugations are oriented at a fixed angle with respect to the vertical direction, and the corrugation angle in adjacent plates are oriented in reverse direction. Points of contact, at the crests of the corrugations, between adjacent plates, form an unconsolidated porous medium with known topology. Modern structured packings have been gaining acceptance in several separation processes, particularly distillation where gas/vapor and liquid flow countercurrently through the packing. In addition, structured packings have been credited with relatively low pressure drop, high efficiency, low holdup, and higher capacity; the packing also can be made corrosion resistive.

de Almeida, V.F.

1999-11-05

188

Development of a Cold Corrugating Process. Technical Progress Report.  

National Technical Information Service (NTIS)

The early work has proceeded through laboratory concept work, laboratory feasibility, pilot trials, and process optimization to the last stage - that being commercial evaluation and demonstration of a cold corrugating system. Although process development ...

1980-01-01

189

Beam-wave interaction in corrugated waveguide filled with plasma  

NASA Astrophysics Data System (ADS)

The dispersion equation of corrugated waveguide filled with plasma were obtained, the plasma electron redistribution and ion channel were taken into account in the study. The dispersion properties are discussed in detail. The relationship between the wave growth and plasma density is investigated. MAGIC PIC code is used to study the microwave radiation features of corrugated waveguide filled with plasma, 6.4MW output power at 100KV voltage is obtained, and microwave radiation efficiency is about 26.7%.

Xie, Wenkai; Chen, Xi; Yan, Yang; Liu, Shenggang

2002-06-01

190

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

SciTech Connect

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

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

1991-01-01

191

Operating characteristics of cooling underground power cables using up sloped long heat pipes in conduit  

NASA Astrophysics Data System (ADS)

Long heat pipes for cooling electric power cables in conduit pipe are required to operate not only in the down slope but also in the up slope. The stable operation of the heat pipe is attained by separating the vapor flow path and the liquid flow path completely, and returning the working fluid condensed by the radiator to the evaporation section end by utilizing a difference in the pressure head. Evaporating section consisting of corrugated metallic pipes and carbon fiber wicks were employed for liquid film evaporation and holding liquid uniformly along an axial length of the pipe. Long heat pipes with a length 100 m, outside diameter 70 mm, and up slope 1/100 were made experimentally and tested. They operated in the normal heat pipe mode, carrying heat 9kW. Further the heat pipes were layed in some cable conduits providing adequate cooling effect.

Oka, K.; Tsuchihashi, H.; Nishimura, Y.; Mohtai, T.; Mochizuki, M.; Mashiko, K.; Yamanouchi, H.

192

Do Steel Bridges Prevent Rail Corrugations?  

NASA Astrophysics Data System (ADS)

Rail corrugations (germ. "Schlupfwellen") are wear pattern, which emerge during the transits of railway vehicles at narrow railway curves (R ? 250 m) and they are a menace to railway operators, especially if their railroad network exists in mountains. Therefore ÖBB started recently a research program "OBO" (Optimierter Bogenoberbau) for better understanding and avoidance of "Schlupfwellen", which is mainly experimentally oriented. As a representative test track was the extended famous narrow curve at the valley of Brixen close to Kitzbühl chosen, and two Measurement sites where there established, one embedded in the ballasted track bed and another one on a steel bridge, situated in this curve. Measuring the passing trains, a rearly astonishing fact was discovered: Whereas in the ballasted track all well known typical features occur (vibration, bending and torsion of the rail,…), which produce the wear created Schlupfwellen and the dedicated grumbling noise, the wheelsets run properly on the steel bridge track and pass "friendly" the associated curve segment! Dicussing the ascertained fact, it was realized that on many European steel bridges such phenomena happens! The paper ends assuming that a broad-band vibration of the rail heads upon the steel bridge reduces the friction coefficient in the wheel/rail contact area ("Flange oilers"). This can be the reason for the smooth travel at the bridge. This may also be the basis for a technical application to overcome the generation of Schlupfwellen?

Meinke, Peter; Stephanides, Johannes

2010-03-01

193

Finite-temperature Casimir force between perfectly metallic corrugated surfaces  

SciTech Connect

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

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

2011-09-15

194

Active control of flow induced resonance in continuous corrugated tubes  

NASA Astrophysics Data System (ADS)

Wind tunnel experiments were conducted to study sound generation from corrugate tubes. Hot-wire and microphone measurements were used to determine the response of the following tube geometries to flow excitation: fully corrugated tube, tube with two corrugations, tube with one corrugation only, and tube with no corrugations at all. For the tube with at least two bumps, it was found that the acoustic output peaks when there is an integer number (K) of vortical structures in the cavities between two bumps. The highest peak corresponds to K=1. Some experiments were undertaken to suppress or at least minimize the sound level. One method which significantly reduced the sound intensity consisted of cutting a narrow strip off the tube along the whole length and replacing it with a smooth strip. This is equivalent to cutting a piece off each bump. A more active method of control consisted of forcing the first bump or cavity by using a set of twelve small speakers positioned in a circle around the tube. This technique only allowed the elimination of the lower sound levels, whereas the K=1 mode was only partially reduced.

Gharib, Morteza

1993-05-01

195

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

196

Pipe Gripper.  

National Technical Information Service (NTIS)

The patent application relates to a device for gripping the exterior surface of a pipe or rod which has a plurality of wedges, each having a concave face which engages the outer surface of the pipe and each having a smooth face opposing the concave face. ...

S. M. Moyers

1974-01-01

197

Dynamic stability of crack fronts: out-of-plane corrugations.  

PubMed

The dynamics and stability of brittle cracks are not yet fully understood. Here we use the Willis-Movchan 3D linear perturbation formalism [J. Mech. Phys. Solids 45, 591 (1997)] to study the out-of-plane stability of planar crack fronts in the framework of linear elastic fracture mechanics. We discuss a minimal scenario in which linearly unstable crack front corrugations might emerge above a critical front propagation speed. We calculate this speed as a function of Poisson's ratio and show that corrugations propagate along the crack front at nearly the Rayleigh wave speed. Finally, we hypothesize about a possible relation between such corrugations and the long-standing problem of crack branching. PMID:23383795

Adda-Bedia, Mokhtar; Arias, Rodrigo E; Bouchbinder, Eran; Katzav, Eytan

2013-01-04

198

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

199

Characteristics of long size thermosyphons made of corrugated tube  

NASA Astrophysics Data System (ADS)

Two-phase closed thermosyphons made of corrugated tube operating in the gravitational field have different characteristics in comparison with that of smooth tube in some items. The cause depends on the accumulated working fluid in the concave space of corrugated tube which tends to induce a dry out phenomenon in the evaporator section. The difference of these characteristics between thermosyphons of corrugated tube and smooth tube seems to amplify with the increment of the length of the thermosyphon. The temperature distribution along the axis of thermosyphon, the heat transport and the heat transfer coefficient as a function of the inclination angle at a fill charge ratio 50 percent of the working fluid were obtained by the experiments and discussed herein. A correlating equation of the heat transfer coefficient was deduced also from the experiments.

Hirashima, Masao; Nishikawa, Yuuji; Taguchi, Masakazu; Negishi, Kanji; Kanero, Ken-Ichi; Matsuoka, Takayoshi

1988-03-01

200

Study of Structurally Efficient Graphite-Thermoplastic Trapezoidal-Corrugation Sandwich and Semi-Sandwich Panels.  

National Technical Information Service (NTIS)

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 be...

D. C. Jegley

1993-01-01

201

Zero-energy states in corrugated bilayer graphene  

NASA Astrophysics Data System (ADS)

Anomalous quantum Hall effects in single-layer and bilayer graphene are related with nontrivial topological properties of electron states (Berry phases ? and 2? , respectively). It was known that the Atiyah-Singer index theorem guarantees, for the case of the single layer, existence of zero-energy states for the case of inhomogeneous magnetic fields assuming that the total flux is nonzero. This leads, in particular, to the appearance of midgap states in corrugated graphene and topologically protects zero-energy Landau level in corrugated single-layer graphene. Here we apply this theorem to the case of bilayer graphene and prove the existence of zero-energy modes for this case.

Katsnelson, M. I.; Prokhorova, M. F.

2008-05-01

202

Three-dimensional train track model for study of rail corrugation  

Microsoft Academic Search

Rail corrugation is a main factor causing the vibration and noise from the structures of railway vehicles and tracks. A calculation model is put forward to analyse the effect of rail corrugation with different depths and wavelengths on the dynamical behaviour of a passenger car and a curved track in detail. Also the evolution of initial corrugation with different wavelengths

X. S. Jin; Z. F. Wen; K. Y. Wang; Z. R. Zhou; Q. Y. Liu; C. H. Li

2006-01-01

203

Three-dimensional train–track model for study of rail corrugation  

Microsoft Academic Search

Rail corrugation is a main factor causing the vibration and noise from the structures of railway vehicles and tracks. A calculation model is put forward to analyse the effect of rail corrugation with different depths and wavelengths on the dynamical behaviour of a passenger car and a curved track in detail. Also the evolution of initial corrugation with different wavelengths

X. S. Jin; Z. F. Wen; K. Y. Wang; Z. R. Zhou; Q. Y. Liu; C. H. Li

2006-01-01

204

Edge-conditioned vector basis functions for the analysis of corrugated antenna feeds  

Microsoft Academic Search

Corrugated circular waveguides are essential components in modern antenna feeds where a high degree of symmetry in the radiation pattern or a very low crosspolarisation is required. The presence of the periodic corrugations in the circular waveguide is reflected in the field distributions of the modes of the structure through the Floquet condition. A common method of analysis of corrugated

Smain Amari; Riidiger Vahldieck; Jens Bornemann

1998-01-01

205

Study of structurally efficient graphite-thermoplastic trapezoidal-corrugation sandwich and semisandwich panels  

Microsoft Academic Search

The structural efficiency of compression-loaded trapezoidal-corrugation sandwich and semisandwich 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 semisandwich 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

Dawn C. Jegley

1994-01-01

206

Analysis of Composite Corrugated Panel Facesheet to Flange Joints  

Microsoft Academic Search

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

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

207

Spoof Surface Plasmon Polariton Modes Propagating Along Periodically Corrugated Wires  

Microsoft Academic Search

In this paper, we analyze in detail the characteristics of surface electromagnetic modes that can propagate along a periodically corrugated, perfectly conducting wire. We show how these modes, termed spoof surface plasmon polaritons, resemble surface plasmon polaritons supported by metallic wires at optical frequencies. The important point is that the dispersion relation of spoof surface plasmon polaritons is mainly controlled

A. I. Fernandez-Dominguez; L. Martin-Moreno; F. J. Garcia-Vidal; S. R. Andrews; S. A. Maier

2008-01-01

208

OBLIQUE VIEW OF POWERHOUSE OFFICE AND CORRUGATED METALCLAD VEHICLE GARAGE ...  

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

OBLIQUE VIEW OF POWERHOUSE OFFICE AND CORRUGATED METAL-CLAD VEHICLE GARAGE AND FUEL PUMP. MAINTENANCE BUILDING IS AT RIGHT CENTER. 90mm lens - Tule River Hydroelectric Complex, CA Highway 190 at North Fork of Middle Fork of Tule River, Springville, Tulare County, CA

209

Wheel-rail noise: impact, random, corrugation and tonal noise  

Microsoft Academic Search

A small survey will be given of wheel-rail contact noise. Distinction is made between impact noise, random noise (amorphous noise), corrugation (rattling noise) and tonal noise (curve shrieking). An account will be given of the causes of the various types of noise, and also of what can be done to diminish them.

J. J. Kalker; F. Périard

1996-01-01

210

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...

211

Performance of a multi-frequency elliptical corrugated horn  

Microsoft Academic Search

An elliptical corrugated horn feeding a single offset-reflector antenna is being considered for an elliptical beam spacecraft antenna system with simultaneous uplink, downlink, and RF tracking capability. The performance of such a horn was measured for the fundamental modes over a wide frequency band and also for higher order tracking modes. The cross-polar response, copolar performance, and tracking pattern performance

D. J. Brain; Y. Kol

1985-01-01

212

Crosspolar performance of an elliptical corrugated-horn antenna  

Microsoft Academic Search

Details are given of a corrugated-horn antenna of elliptical cross-section and its electrical performance. It is shown that this type of horn is suitable for use in systems where a high degree of polarization purity is required in both planes of polarization.

R. F. E. Guy; R. W. Ashton

1979-01-01

213

Hybrid RC Building Structures with Corrugated Steel Shear Panels  

Microsoft Academic Search

Summary This research aims to establish an economical seismic response controlling system of RC frames using corrugated steel shear panels (CSSP), which was originally proposed for building structures by Mo and Perng in 2000. The hybrid system with CSSP has large ductility and possibly decreases to construction cost by large amount. The advantage of using CSSP in described from the

Susumu KONO; Yukako ICHIOKA

214

Magnetic Wave Interactions in a Periodically Corrugated YIG Film  

Microsoft Academic Search

The magnetic wave interactions in a YIG film having periodically corrugated surfaces are investigated for the ease of magnetization parallel to the propagation direction. By a singular boundary perturbation procedure, the coupled-mode equations governing the nature of the interactions are deduced and analyzed to obtain the characteristics of the interactions. Representative numerical results are presented to reveal the characteristics of

S. R. Seshadri

1979-01-01

215

Condensation of refrigerants flowing inside smooth and corrugated tubes  

SciTech Connect

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

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

1995-07-01

216

Aerodynamic effects of corrugation and deformation in flapping wings of hovering hoverflies.  

PubMed

We investigated the aerodynamic effects of wing deformation and corrugation of a three-dimensional model hoverfly wing at a hovering condition by solving the Navier-Stokes equations on a dynamically deforming grid. Various corrugated wing models were tested. Insight into whether or not there existed significant aerodynamic coupling between wing deformation (camber and twist) and wing corrugation was obtained by comparing aerodynamic forces of four cases: a smooth-plate wing in flapping motion without deformation (i.e. a rigid flat-plate wing in flapping motion); a smooth-plate wing in flapping motion with deformation; a corrugated wing in flapping motion without deformation (i.e. a rigid corrugated wing in flapping motion); a corrugated wing in flapping motion with deformation. There was little aerodynamic coupling between wing deformation and corrugation: the aerodynamic effect of wing deformation and corrugation acting together was approximately a superposition of those of deformation and corrugation acting separately. When acting alone, the effect of wing deformation was to increase the lift by 9.7% and decrease the torque (or aerodynamic power) by 5.2%, and that of wing corrugation was to decrease the lift by 6.5% and increase the torque by 2.2%. But when acting together, the wing deformation and corrugation only increased the lift by ~3% and decreased the torque by ~3%. That is, the combined aerodynamic effect of deformation and corrugation is rather small. Thus, wing corrugation is mainly for structural, not aerodynamic, purpose, and in computing or measuring the aerodynamic forces, using a rigid flat-plate wing to model the corrugated deforming wing at hovering condition can be a good approximation. PMID:22266123

Du, Gang; Sun, Mao

2012-01-12

217

DPSM modeling for studying interaction between bounded ultrasonic beams and corrugated plates with experimental verification.  

PubMed

Periodically corrugated structures play an important role in the field of vibration control and for designing structures with desired acoustic band gaps. Analytical solutions for corrugated plates are available for well-defined, smooth corrugations, such as sinusoidal corrugations that are not very common in the real world. Often corrugated plates are fabricated by cutting grooves at regular intervals in a flat plate. No analytical solution is available to predict the wave propagation behavior in such a periodically corrugated plate in which the equation of the plate surface changes periodically between a planar fiat surface and a nonplanar parabolic groove. This problem is solved here for steady-state case by a newly developed semianalytical technique called distributed point source method (DPSM), and the theoretical predictions are compared with the experimental results generated by reflecting a bounded 2.25 MHz ultrasonic beam by a fabricated corrugated plate. The main difference that is observed in the reflected beam profile from a flat plate and a corrugated plate is that the back-scattering effect is much stronger for the corrugated plate, and the forward reflection is stronger for the flat plate. The energy distribution inside the corrugated plate also shows backward propagation of the ultrasonic energy. PMID:17941392

Das, Samik; Dao, Cac Minh; Banerjee, Sourav; Kundu, Tribikram

2007-09-01

218

Corrugated interfaces in multiphase core-annular flow  

NASA Astrophysics Data System (ADS)

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

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

2010-08-01

219

Thermally Tuning Terahertz Surface Plasmon Polaritons in Corrugated Semiconductor Films  

Microsoft Academic Search

In this work, we show that surface plasmon polaritons (SPPs) at terahertz (THz) frequencies can be tuned by changing the temperature in a periodically corrugated thin film of indium antimonide (InSb) sandwiched between air and dielectric. When a THz electromagnetic wave illuminates the structure, the temperature-dependent THz SPPs can be excited, and the first and second-order modes and their cross-couplings

Xin Wu; Ruwen Peng; De Li; Ruili Zhang; Renhao Fan; Claudio Ferrari; Mu Wang

2009-01-01

220

Doubly-corrugated spoof-insulator-spoof waveguides  

NASA Astrophysics Data System (ADS)

We explore guided modes in metallic "spoof-insulator-spoof" (SIS) waveguides: parallel plate structures with subwavelength corrugation on the surfaces of both conductors. A dispersion relation for SIS waveguides is analytically obtained. The modes in the structure arise from the coupling of conventional parallel plate waveguide modes with the localized modes of the grooves. SIS waveguides can be engineered to guide modes with low group velocities and SIS tapers can be used to convert light between photonic modes and plasmonic ones.

Kats, Mikhail A.; Woolf, David; Blanchard, Romain; Yu, Nanfang; Capasso, Federico

2012-02-01

221

Production of hemicellulosic sugars and glucose from residual corrugated cardboard  

Microsoft Academic Search

Corrugated cardboard samples were subjected to two-step saccharification. A first prehydrolysis stage was carried out to solubilise the hemicellulosic fraction as hemicellulosic sugars, and the solid phase from prehydrolysis was used as a substrate for the enzymic hydrolysis of cellulose. The prehydrolysis step was carried out for 0–180min in media containing 1–3wt.% of H2SO4 and the fraction of solid recovered

R Yáñez; J. L Alonso; J. C Parajó

2004-01-01

222

Corrugated quantum well infrared photodetectors for far infrared detection  

Microsoft Academic Search

We have extended our investigation of corrugated quantum well infrared photodetector focal plane arrays (FPAs) into the far infrared regime. Specifically, we are developing the detectors for the thermal infrared sensor (TIRS) used in the Landsat Data Continuity Mission. To maintain a low dark current, we adopted a low doping density of 0.6×1018 cm-3 and a bound-to-bound state detector. The

Kwong-Kit Choi; Murzy D. Jhabvala; David Forrai; Jason Sun; Darrel Endres

2011-01-01

223

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

224

Piping geofluids  

Microsoft Academic Search

In many cases the source of geothermal fluid to be used for a direct use application is located some distance away from the user. This requires a transmission pipeline to transport the geothermal fluid. Even in the absence of transmission line requirements it is frequently advisable to employ other than standard piping materials. Geothermal energy for direct use applications is

P. J. Lienau; K. Rafferty

2009-01-01

225

Evaporation characteristics of R22 flowing inside a corrugated tube  

SciTech Connect

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

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

1992-07-01

226

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

SciTech Connect

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

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

2000-10-01

227

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

228

Geometrical investigations of the Casimir effect: Thickness and corrugation dependencies  

NASA Astrophysics Data System (ADS)

In the quantum theory the vacuum is not empty space. It is considered as a state of infinite energy arising due to zero point fluctuations of the vacuum. Calculation of any physically relevant process requires subtracting this infinite energy using a procedure called normalization. As such the vacuum energy is treated as an infinite constant. However, it has been established beyond doubt that mere subtraction of this infinite constant does not remove the effect of vacuum fluctuations and it cannot be treated just as a mathematical artifact. The presence of boundaries, which restricts the vacuum field, causes vacuum polarization. Any non-trivial space-time topology can cause similar effects. This is manifested as the Casimir effect, whereby the boundaries experience a force due to a change in the energy of the vacuum. To calculate the vacuum energy we treat the boundaries or other restrictive conditions as classical backgrounds, which impose boundary conditions on the solution of the vacuum field equations. Alternatively, we can incorporate the classical background in the Lagrangian of the system as classical potentials, which automatically include the boundary conditions in the field equations. Any change in the boundary conditions changes the vacuum energy and consequently the Casimir force is experienced by the boundaries. In this dissertation we study the geometric aspect of the Casimir effect. We consider both the scalar field and the physically relevant electromagnetic field. After a brief survey of the field in Chapter 1, we derive the energy expression using the Schwinger's quantum action principle in Chapter 2. We present the multiple scattering formalism for calculating the vacuum energy, which allows us to calculate the interaction energy between disjoint bodies and subtract out the divergent terms from the beginning. We then solve the Green's dyadic equation for the electromagnetic field interacting with the planar background surfaces, where we can decompose the problem into two transverse scalar modes. In Chapter 3 we collect all the solutions for the scalar Green's functions for the planar and the cylindrical geometries, which are relevant for this dissertation. In Chapter 4 we derive the interaction energy between two dielectric slabs of finite thickness. Taking the thickness of the slabs to infinity leads to the Lifshitz results for the two infinite dielectric semi-spaces, while taking the dielectric permittivity to infinity gives the well-known Casimir energy between two perfect conductors. We then present a simple model to consider the thin-plate limit (taking the thickness of the slabs to zero) based on Drude-Sommerfeld free electron gas model, which modifies the plasma frequency of the material to include the finite size dependence. We get a non-vanishing result for the Lifshitz energy in the slab thickness going to zero limit. This is remarkable progress as it allows us to understand the infinitesimal thickness limit and opens a possibility of extending this model to apply it to graphene and other two dimensional surfaces. The Casimir and Casimir-Polder results in the perfect conductor limit give us the expected results. In Chapter 5 we study the lateral Casimir torque between two concentric corrugated 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 the cylinders (relative to the difference in their radii) while keeping the corrugation wavelength fixed. In Chapter 6 we calculate the lateral Casimir energy between corrugated parallel dielectric slabs of finite thickness using the multiple scattering formalism in the perturbative approximation and obt

Parashar, Prachi

229

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

Microsoft Academic Search

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

D. Jegley

1993-01-01

230

Substrate surface corrugation effects on the electronic transport in graphene nanoribbons  

NASA Astrophysics Data System (ADS)

In this work, the electronic transport in armchair graphene nanoribbons in the presence of surface corrugation is studied. The non-equilibrium Green's function along with tight-binding model for describing the electronic band structure is employed to investigate the electronic properties of graphene nanoribbons. The effects of surface corrugation parameters, such as corrugation amplitude and correlation length, on the electronic properties of the graphene nanoribbons are studied. The mean free path of carriers is extracted and its dependency on the corrugation amplitude and correlation length is investigated.

Babaee Touski, Shoeib; Pourfath, Mahdi

2013-09-01

231

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

232

Effects of mismatch strain and substrate surface corrugation on morphology of supported monolayer graphene  

NASA Astrophysics Data System (ADS)

Graphene monolayers supported on oxide substrates have been demonstrated with superior charge mobility and thermal transport for potential device applications. Morphological corrugation can strongly influence the transport properties of the supported graphene. In this paper, we theoretically analyze the morphological stability of a graphene monolayer on an oxide substrate, subject to van der Waals interactions and in-plane mismatch strains. First, we define the equilibrium separation and the interfacial adhesion energy as the two key parameters that characterize the van der Waals interaction between a flat monolayer and a flat substrate surface. By a perturbation analysis, a critical compressive mismatch strain is predicted, beyond which the graphene monolayer undergoes strain-induced instability, forming corrugations with increasing amplitude and decreasing wavelength on a perfectly flat surface. When the substrate surface is not perfectly flat, the morphology of graphene depends on both the amplitude and the wavelength of surface corrugation. A transition from conformal (corrugated) to nonconformal (flat) morphology is predicted. The effects of substrate surface corrugation on the equilibrium mean thickness of the supported graphene and the interfacial adhesion energy are analyzed. Furthermore, by considering both the substrate surface corrugation and the mismatch strain, it is found that, while a tensile mismatch strain reduces the corrugation amplitude of graphene, a corrugated substrate surface promotes strain-induced instability under a compressive strain. These theoretical results suggest possible means to control the morphology of supported graphene monolayers by substrate surface patterning and strain engineering.

Aitken, Zachary H.; Huang, Rui

2010-06-01

233

Observation of Surface Corrugation of Highly Oriented Pyrolytic Graphite by Scanning Tunneling Microscope in Air  

Microsoft Academic Search

The apparent surface corrugation of highly oriented pyrolytic graphite (HOPG) was investigated with a scanning tunneling microscope (STM) in air using mechanically polished PtIr tips. It was found that the tunneling resistance was the most dominant parameter governing the observed atomic corrugation. The tunneling resistance was defined by the ratio of bias voltage to tunneling current required for STM measurements.

Takeo Iri; Hiroaki Shiba; Hiroyuki Nishikawa

1992-01-01

234

Three-dimensional train track model for study of rail corrugation  

NASA Astrophysics Data System (ADS)

Rail corrugation is a main factor causing the vibration and noise from the structures of railway vehicles and tracks. A calculation model is put forward to analyse the effect of rail corrugation with different depths and wavelengths on the dynamical behaviour of a passenger car and a curved track in detail. Also the evolution of initial corrugation with different wavelengths is investigated. In the numerical analysis, Kalker's non-Hertzian rolling contact theory is modified and used to calculate the frictional work density on the contact area of the wheel and rail in rolling contact. The material loss per unit area is assumed to be proportional to the frictional work density to determine the wear depth of the contact surfaces of the curved rails. The combined influences of the corrugation development and the vertical and lateral coupled dynamics of the passenger car and the curved track are taken into account. The numerical results indicate that: (1) the corrugation with high passing frequencies has a great influence on the dynamical performance of the wheelset and track, but little on the car-body and the bogie frame; (2) the deeper the corrugation depth is, the greater the influence and the rail material wear are; but the longer the corrugation wavelength is, the smaller the influence and the wear are; and (3) the initial corrugation with a fixed wavelength on the rail running surface decreases with increasing number of the passenger car passages.

Jin, X. S.; Wen, Z. F.; Wang, K. Y.; Zhou, Z. R.; Liu, Q. Y.; Li, C. H.

2006-06-01

235

Anomalous light reflection from a surface of a corrugated waveguide with amplification  

Microsoft Academic Search

The problem of light reflection from a surface of a corrugated waveguide with amplification is solved. It is shown that a significant increase in the reflection coefficient and a decrease in the spectral bandwidth of the reflection peak occur with an increase in the waveguide gain. A corrugated thin-film waveguide is indicated schematically.

I. A. Avrutskii; V. A. Sychugov

1989-01-01

236

A design chart for the plastic collapse of corrugated cylinders under external pressure  

Microsoft Academic Search

The paper presents a theoretical and an experimental investigation into the plastic collapse of circular steel corrugated cylinders under external hydrostatic pressure. The experimental investigation gives a detailed study of 9 steel corrugated cylinders which were tested to destruction. Six of these cylinders failed by plastic non-symmetric bifurcation buckling and three failed by plastic axisymmetric deformation. The results of these

C. T. F. Ross; A. Terry; A. P. F. Little

2001-01-01

237

Experiments on Normal Modes in a Tank with Corrugated Bottom  

NASA Astrophysics Data System (ADS)

We report an experimental investigation of standing waves in a rectangular container of corrugated bottom partially filled with water. The study was stimulated by the theory of Howard and YuootnotetextJ. Fluid. Mech. (2007), vol. 593, pp. 209-234.^,ootnotetextJ. Fluid. Mech. (2010), vol. 659, pp. 484-504. predicting the existence of resonant normal modes --- called Bragg resonance --- wherein the amplitude grows exponentially, either from one end of the channel to the other or from the center out in each direction, depending on the endwall phases of the corrugated bottom. The tank, with adjustable length between 450 and 490 cm, width 13 cm, and height 30 cm, is fitted with a sinusoidal bottom (made of high density polyurethane foam) of wavelength 52 cm and peak-to-peak amplitude 5 cm. Waves are excited by shaking the container in periodic horizontal motion using an electrical motor. The amplitude of the standing waves was recorded using two sensitive pressure probes and also observed and filmed through the transparent acrylic walls. Experimental results are in essential agreement with the theory.

Herczynski, Andrzej; Weidman, Patrick; Howard, Louis; Yu, Jie

2011-11-01

238

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

239

Colossal Corrugations in Freestanding Graphene Observed with STM  

NASA Astrophysics Data System (ADS)

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

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

2012-02-01

240

The Sacred Calf Pipe.  

ERIC Educational Resources Information Center

|Tells how the author learned of and recorded the list of Sioux tribe members who have kept the White Buffalo Calf Pipe. Reviews the legend surrounding the origin of the pipe and describes the succession of pipe-keepers and how they inherit the pipe. (Author/AEM)|

Simms, Thomas E.

1987-01-01

241

Pipe protection bibliography  

Microsoft Academic Search

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

1987-01-01

242

Modeling noncontact atomic force microscopy resolution on corrugated surfaces.  

PubMed

Key developments in NC-AFM have generally involved atomically flat crystalline surfaces. However, many surfaces of technological interest are not atomically flat. We discuss the experimental difficulties in obtaining high-resolution images of rough surfaces, with amorphous SiO(2) as a specific case. We develop a quasi-1-D minimal model for noncontact atomic force microscopy, based on van der Waals interactions between a spherical tip and the surface, explicitly accounting for the corrugated substrate (modeled as a sinusoid). The model results show an attenuation of the topographic contours by ~30% for tip distances within 5 Å of the surface. Results also indicate a deviation from the Hamaker force law for a sphere interacting with a flat surface. PMID:22496996

Burson, Kristen M; Yamamoto, Mahito; Cullen, William G

2012-03-13

243

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

244

Nonlinear dynamics of corrugated doping fronts in organic optoelectronic devices  

NASA Astrophysics Data System (ADS)

Recently, it was demonstrated that electrochemical doping fronts in organic semiconductors exhibit a new fundamental instability growing from multidimensional perturbations [Bychkov , Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.107.016103 107, 016103 (2011)]. In the instability development, linear growth of tiny perturbations goes over into a nonlinear stage of strongly distorted doping fronts. Here we develop the nonlinear theory of the doping front instability and predict the key parameters of a corrugated doping front, such as its velocity, in close agreement with the experimental data. We show that the instability makes the electrochemical doping process considerably faster. We obtain the self-similar properties of the front shape corresponding to the maximal propagation velocity, which allows for a wide range of controlling the doping process in the experiments. The developed theory provides the guide for optimizing the performance of organic optoelectronic devices such as light-emitting electrochemical cells.

Bychkov, V.; Jukimenko, O.; Modestov, M.; Marklund, M.

2012-06-01

245

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

246

Scaling of premixed turbulent flames in the corrugated regime  

SciTech Connect

A novel apparatus for studying premixed combustion, involving the flow through a wide-angled diffuser, is described. Flames in pure methane/air mixtures and in methane/hydrogen/air have been stabilised at various heights in the diffuser, with various types of turbulence generators at inlet. The stabilisation conditions thus embraced a range of turbulence levels and integral length scales in the corrugated flamelet regime. Particle image velocimetry and planar laser-induced fluorescence were deployed to obtain the instantaneous velocity field in the unburnt mixture and the location of the flame front. Ensemble averages over 200 images allowed the statistics for 2-D flamelet surface density and the thickness of the flame brush to be measured in flames that were nearly planar in the mean. The flamelet surface density S was shown to be related to the length scale and the turbulence level, albeit in a nonlinear manner. However, there was no clear correlation for the flame brush thickness {delta}{sub T}, two different perforated plates generating turbulence at the same level and of the same length scale but giving very different thicknesses. Integrating S across the flame and combining with information from elsewhere on the effect of stretch on the laminar burning velocity, the consumption speed was estimated. As in all determinations of this parameter in the literature, this was found to be very much less than the turbulent displacement speed. Residual mean flame curvature is not thought to be sufficient to account for this, and explanations are being sought in a more complex response of the flamelets to the turbulence than just pure corrugation. (author)

Lawn, C.J. [Department of Engineering, Queen Mary, University of London, Mile End Road, London, E1 4NS (United Kingdom); Schefer, R.W. [Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551-0969 (United States)

2006-07-15

247

Plasmon resonance absorption in layered structures of silver with periodic corrugation  

SciTech Connect

Plasmon resonance absorption in periodically corrugated layered structures of silver was studied by the photoacoustic method. The layered structures were self-supporting and corrugated with a period of 1888 nm and amplitude varying from 6 to 12 nm, depending on the thickness. Experimental results of resonance absorption of 633-nm photons were analyzed in terms of the propagation and damping constants of coupled modes of surface plasmons. The coupling efficiency of incident photons to these modes was found to be strongly dependent on corrugation amplitude and layer thickness.

Arakawa, E.T.; Inagaki, T.; Goudonnet, J.P.

1987-01-01

248

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

249

Quasi-phase matching of third harmonic generation in corrugated discharge capillary  

NASA Astrophysics Data System (ADS)

Quasi-phase matching third harmonic of Ti:sapphire laser was measured by propagation through corrugated discharge capillaries. The 1 cm long capillary with periodical varying inner radius was used with corrugation frequency of 200 ?m. The longitudinal plasma density was periodically varied by a discharge current ablating the inner capillary walls, altering the refractive index accordingly. Average plasma density measured was 1018 cm-3 at minimum corrugation radius. Peak laser intensity was 1010 W/cm2 allowing enough pondermotive energy to the electron for high harmonic generation.

Katzir, Y.; Ferber, Y.; Megidish, E.; Zigler, A.; Milchberg, H. M.

2011-10-01

250

Insulated pipe clamp design  

SciTech Connect

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

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

1980-01-01

251

Flexible ocean upwelling pipe  

DOEpatents

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

252

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

USGS Publications Warehouse

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

Barringer, T. H.

1996-01-01

253

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

254

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

255

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

256

INTEGRATED AND FIBER OPTICS: Anomalous reflection of light from the surface of an amplifying corrugated waveguide  

Microsoft Academic Search

The problem of reflection of light from the surface of an amplifying corrugated waveguide is solved. An increase in the waveguide gain increases considerably the reflection coefficient and reduces the spectral width of the reflection peak.

I. A. Avrutskii; V. A. Sychugov

1989-01-01

257

Corrugated velocity patterns in the spiral galaxies: NGC 278, NGC 1058, NGC 2500 & UGC 3574 .  

NASA Astrophysics Data System (ADS)

In this work we address the study of the detection in Halpha of a radial corrugation in the vertical velocity field in a sample of four nearly face-on, spiral galaxies. The geometry of the problem is a main criterion in the selection of the sample as well as of the azimuthal angle of the slits. These spatial corrugations must be equally associated with wavy vertical motions in the galactic plane with a strong large-scale consistency. Evidence of these kinematic waves were first detected in the analysis of the rotation curves of spiral galaxies (eg Vaucoleurs & de Vaucaleurs 1963, Pismis 1965), but it was not until 2001 that Alfaro et al. analyzed in more detail the velocity corrugations in NGC 5427 and a possible physical mechanism for their origin. The aim of this study is to analyze the corrugated velocity pattern in terms of the star formation processes. We describe the geometry of the problem and establish its fundamental relationships.

Sánchez Gil, M. C.; Alfaro, E. J.; Pérez, E.

258

14. DETAIL OF SOUTHWEST FRONT OF WAREHOUSE, SHOWING CORRUGATED PLASTER/ASBESTOS ...  

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

14. DETAIL OF SOUTHWEST FRONT OF WAREHOUSE, SHOWING CORRUGATED PLASTER/ASBESTOS WALLS, WINDOWS AND ROOF. VIEW TO NORTHEAST. - Commercial & Industrial Buildings, International Harvester Company Showroom, Office & Warehouse, 10 South Main Street, Dubuque, Dubuque County, IA

259

Effects of positive and negative affect on electromyographic activity over zygomaticus major and corrugator supercilii.  

PubMed

Pleasant stimuli typically elicit greater electromyographic (EMG) activity over zygomaticus major and less activity over corrugator supercilii than do unpleasant stimuli. To provide a systematic comparison of these 2 measures, the authors examined the relative form and strength of affective influences on activity over zygomaticus major and corrugator supercilii. Self-reported positive and negative affective reactions and facial EMG were collected as women (n = 68) were exposed to series of affective pictures, sounds, and words. Consistent with speculations based on known properties of the neurophysiology of the facial musculature, results revealed a stronger linear effect of valence on activity over corrugator supercilii versus zygomaticus major. In addition, positive and negative affect ratings indicated that positive and negative affect have reciprocal effects on activity over corrugator supercilii, but not zygomaticus major. PMID:14696731

Larsen, Jeff T; Norris, Catherine J; Cacioppo, John T

2003-09-01

260

The compressive and shear responses of corrugated and diamond lattice materials  

Microsoft Academic Search

Corrugated and diamond lattice materials have been manufactured as the cores of sandwich panels by slotting together stainless steel sheets and then brazing together the assembly. The out-of-plane compressive, transverse shear and longitudinal shear responses of the corrugated cores have been measured at three relative densities 0.03?¯?0.10 and compared with analytical and finite element (FE) predictions. Finite element models are

F. Cotea; V. S. Deshpande; N. A. Fleck; A. G. Evans

2006-01-01

261

A wide-band corrugated rectangular waveguide phase shifter for cryogenically cooled receivers  

Microsoft Academic Search

A wide-band phase shifter rectangular in cross section with transverse corrugations on all four walls is presented. The loading for the two orthogonal modes is different and is achieved by choosing dissimilar corrugation parameters. This phase shifter measures a return loss of -25 dB or better and differential phase shift of 90°±3.3° between 18.9-26.5 GHz, This all-metal robust phase shifter

S. Srikanth

1997-01-01

262

Interference of waveguide modes during light reflection from the surface of a corrugated waveguide  

Microsoft Academic Search

Experimental results are presented on the effect of phase shift between corrugations of a double-sided corrugated waveguide on anomalous light reflection under normal light incidence on the waveguide surface. The differences in the behavior of the short-wavelength and long-wavelength peaks of the reflection are shown to be governed by the relative position of the interference maxima and mimina of the

I. A. Avrutskii; V. A. Sychugov

1988-01-01

263

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

Microsoft Academic Search

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

Mikhail Karyakin; Taisiya Sigaeva

264

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

265

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

2011-12-01

266

Quantum wires and quantum dots on corrugated (311) surfaces: potential applications in optoelectronics  

Microsoft Academic Search

GaAs and InGaAs (311) surfaces may be spontaneously corrugated with a height and a period controlled by the film composition, strain and polarity of the substrate. Using image-processed high-resolution transmission electron microscopy we found that both GaAs - AlAs interfaces in short-period superlattices (SPSL) grown on (311)A GaAs substrates are corrugated with a height of 1 nm and a lateral

Nikolai N. Ledentsov; D. Litvinov; D. Gerthsen; G. A. Ljubas; V. V. Bolotov; B. R. Semyagin; Vitaly A. Shchukin; Ilja P. Soshnikov; Victor M. Ustinov; Dieter Bimberg

2002-01-01

267

Oceanic corrugated surfaces and the strength of the axial lithosphere at slow spreading ridges  

NASA Astrophysics Data System (ADS)

We analyse the topography and gravity signature of 39 corrugated surfaces formed over the past 26 myrs in the footwall of axial detachment faults at the eastern Southwest Indian Ridge. These corrugated surfaces appear to have formed at a melt supply about half the global melt supply average for mid-ocean ridges, and we find that their presently elevated topography, relative to adjacent non-corrugated seafloor, was mostly acquired at the end of their formation, at the “termination stage”. This configuration, which also characterizes many off-axis corrugated surfaces in other oceans, suggests that the plate flexural rigidity was very low during the formation of the corrugated surface, and increased significantly at the termination stage. Following Buck (1988), we hypothesize that stresses related to bending of the plate cause internal deformation and damage in the footwall of the fault, which is associated with weakening. As a possible mechanism for enhanced footwall weakening while corrugated surfaces form, we propose the formation of weak shear zones coated with hydrous minerals such as talc, amphibole, chlorite and serpentine, in mantle-derived ultramafics next to gabbro intrusions. If this hypothesis is correct, the amount of footwall weakening and roll-over along axial detachment faults at slow spreading ridges may be controlled both by access to hydrothermal fluids in the footwall of the detachment, and by the abundance and distribution of gabbros intrusions in exhumed ultramafics.

Cannat, Mathilde; Sauter, Daniel; Escartín, Javier; Lavier, Luc; Picazo, Suzanne

2009-10-01

268

Corrugator Muscle Responses Are Associated With Individual Differences in Positivity-Negativity Bias  

PubMed Central

Corrugator supercilii muscle activity is considered an objective measure of valence because it increases in response to negatively valenced facial expressions (angry) and decreases to positive expressions (happy). The authors sought to determine if corrugator activity could be used as an objective measure of positivity-negativity bias. The authors recorded corrugator responses as participants rated angry, happy, and surprised faces as “positive” or “negative.” The critical measure of bias was the percentage of positive versus negative ratings assigned to surprised faces by each participant. Reaction times for surprise expressions were longer than for happy and angry expressions, consistent with their ambiguous valence. Participants who tended to rate surprised faces as negative showed increased corrugator activity to surprised faces, whereas those who tended to rate surprise as positive showed decreased activity. Critically, corrugator responses reflected the participants’ bias (i.e., their tendency to rate surprise as positive or negative). These data show that surprised faces constitute a useful tool for assessing individual differences in positivity-negativity bias, and that corrugator activity can objectively reflect this bias.

Neta, Maital; Norris, Catherine J.; Whalen, Paul J.

2009-01-01

269

Effect of track irregularities on initiation and evolution of rail corrugation  

NASA Astrophysics Data System (ADS)

The effect of track irregularities on rail corrugation is investigated in detail with the numerical method when a wheelset is steadily curving. The irregularities considered in the analysis include initial running surface of rail with periodically varying and different wave length, stochastic roughness on the rail running surface, and vertical uneven support stiffness of the rail due to the discrete sleeper supports. The numerical method considers a combination of Kalker's rolling contact theory with non-Hertzian to be modified, a linear frictional work model and a vertical dynamics model of railway vehicle coupled with a curved track. The model is also validated by an experiment with a full scale facility. The influence of different speeds of wheelset curving on the development of the corrugation is taken into account in the calculation. The numerical results indicate that (1) for existing of the initial corrugation of new rail with any wavelength the depth from the peak to trough of it decreases gradually with an increase of wheelset passage, but the initial corrugation evolved has a tendency to move in the rolling direction, (2) the amplitude of the initial stochastic roughness of new rail is gradually leveled out and but a corrugation with very small depth and a few fixed passing frequencies is initiated, the passing frequencies are the same as the natural frequencies of the track, and (3) the discrete rail supports by sleepers have a great influence on the formation of the corrugation.

Jin, X. S.; Wen, Z. F.; Wang, K. Y.

2005-07-01

270

Transfer-matrix approach based on modal analysis for modeling corrugated long-period fiber gratings.  

PubMed

A transfer-matrix method is developed for modeling a corrugated long-period fiber grating. Cladding-mode resonance in such a corrugated structure can be controlled by the applied tensile stress based on the photoelastic effect. A first-order vectorial perturbation expansion is used to derive the mode fields of the two basic regions under the strain-induced index perturbation. Because the etched cladding radius is much smaller than the unetched radius, the effect of the corrugated structure on cladding modes cannot be treated as a small perturbation. Thus the conventional coupled-mode theory is inadequate for the modeling of such a structure. Based on a self-consistent mode-matching technique, mode coupling within the corrugated structure can be described by a set of transfer matrices. We apply the formulation to the calculation of the transmission spectra of a corrugated long-period grating and compare the calculated with the experimental results. The transfer-matrix approach is found to account well for the features of the transmission spectra of the corrugated long-period gratings. PMID:18360487

Chern, G W; Wang, L A; Lin, C Y

2001-09-01

271

Miniature Heat Pipes.  

National Technical Information Service (NTIS)

Small Business Innovation Research contracts from Goddard Space Flight Center to Thermacore Inc. have fostered the company work on devices tagged 'heat pipes' for space application. To control the extreme temperature ranges in space, heat pipes are import...

1997-01-01

272

Study on Plastic Pipes.  

National Technical Information Service (NTIS)

District heating pipelines are usually placed by using medium pipes consisting of steel; it is only in some exceptional cases that plastics are used. In future, plastics could be used for district heating subdistribution in competition with steel pipes pr...

A. Tautz

1982-01-01

273

Flexible Pipe Technology.  

National Technical Information Service (NTIS)

The conference proceedings contain 12 papers. The topics covered are: Technology, products and offshore applications; Steel reinforced elastomer pipes - Design approach and performance characteristics; Flexible pipe installation techniques; Gullfaks ''A''...

1986-01-01

274

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

275

Abrasion resistant heat pipe  

Microsoft Academic Search

A specially constructed heat pipe is described for use in fluidized bed combustors. Two distinct coatings are spray coated onto a heat pipe casing constructed of low thermal expansion metal, each coating serving a different purpose. The first coating forms aluminum oxide to prevent hydrogen permeation into the heat pipe casing, and the second coating contains stabilized zirconium oxide to

1984-01-01

276

Abrasion resistant heat pipe  

Microsoft Academic Search

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

Donald M

1984-01-01

277

Bonded flexible pipe  

Microsoft Academic Search

This paper presents an overview of bonded flexible pipe improvements primarily driven by environmental safety as applied to offshore development using mobile production systems. Bonded pipe is a flexible pipe where the steel reinforcement is integrated and bonded to a vulcanized elastomeric material. Textile material is included in the structure to obtain additional structural reinforcement or to separate elastomeric layers.

Val M. Northcutt

2000-01-01

278

Heat pipe system  

Microsoft Academic Search

A heat pipe diode device for transferring heat from a heat source component to a heat sink wall is described. It contains a heat pipe body member attached to the best source; the heat source having a wall forming at least a portion of the normal evaporator section of the heat pipe diode; a working fluid within the body member;

H. L. Kroebig; F. J. Riha

1974-01-01

279

Inspecting flexible pipe  

SciTech Connect

Principal modes of failure as well as defects which cause leakage or cross-section damage are discussed. The author explains in detail how traditional problems associated with inspecting flexible pipe, which include discriminating between pipe layers, corrosion monitoring and the use of intelligent pigs, can be related to flexible pipe's complex construction and complex behavior. Proper pig selection and operations are emphasized.

Neffgen, J.M. (Pag-O-Flex, AS (NO))

1990-12-01

280

Controlled heat pipes  

NASA Astrophysics Data System (ADS)

A thermodynamic analysis of the operation of controlled heat pipes is presented. Topics covered include a classification of controlled heat pipes; attention is given to heat pipes in the dry saturated vapor regime, with a superheated vapor, with a supercooled liquid phase, with a superheated vapor and a supercooled liquid phase, and with moist vapor. Also covered are heat pipes with passive or active control, and the classification of controlled heat pipes according to the function (application) realized. Applications include heat diodes, temperature stabilizers, a heat bridge, a heat flow regulator, and a heat switch.

Vasilev, L. L.; Konev, S. V.; Tomchak, V.; Danelevich, Ia.

1983-07-01

281

Controlled heat pipes  

NASA Astrophysics Data System (ADS)

A thermodynamic analysis of the operation of controlled heat pipes is presented. Topics covered include a classification of controlled heat pipes; attention is given to heat pipes in the dry saturated vapor regime, with a superheated vapor, with a supercooled liquid phase, with a superheated vapor and a supercooled liquid phase, and with moist vapor. Also covered are heat pipes with passive or active control, and the classification of controlled heat pipes according to the function (application) realized. Applications include heat diodes, temperature stabilizers, a heat bridge, a heat flow regulator, and a heat switch.

Vasilev, L. L.; Konev, S. V.; Tomchak, V.; Danelevich, Ia.

1984-01-01

282

Critical instability and friction scaling of fluid flows through pipes with rough inner surfaces.  

PubMed

It has been shown experimentally over nearly 80 years that surface fine roughness of circular pipes has a crucial effect on the natural transition to turbulence. In this Letter, a theoretical explanation is suggested for the roughness-induced instability. Once the nonlinear effect of roughness is introduced (through a pipe with fine corrugation surface), the mean velocity profile becomes unstable to three-dimensional, asymmetric, and helical traveling waves at moderate Reynolds numbers. The threshold of the aspect ratio or shape factor of the roughness element required to cause instability scales as Re-2. Inspired by the current model, a scaling form is proposed and the scaled friction factor measurements in rough pipes collapse onto a universal curve. PMID:20366316

Tao, Jianjun

2009-12-28

283

Critical Instability and Friction Scaling of Fluid Flows through Pipes with Rough Inner Surfaces  

NASA Astrophysics Data System (ADS)

It has been shown experimentally over nearly 80 years that surface fine roughness of circular pipes has a crucial effect on the natural transition to turbulence. In this Letter, a theoretical explanation is suggested for the roughness-induced instability. Once the nonlinear effect of roughness is introduced (through a pipe with fine corrugation surface), the mean velocity profile becomes unstable to three-dimensional, asymmetric, and helical traveling waves at moderate Reynolds numbers. The threshold of the aspect ratio or shape factor of the roughness element required to cause instability scales as Re-2. Inspired by the current model, a scaling form is proposed and the scaled friction factor measurements in rough pipes collapse onto a universal curve.

Tao, Jianjun

2009-12-01

284

Pipe-to-pipe impact program  

SciTech Connect

The objective of this research was to determine the extent of damage that occurs when two pipes experience an impact event due to one whipping against the other. The research was conducted through experimental and analytical approaches. The former required the development of a specialized impact machine that could accelerate a whipping pipe with sufficient energy to cause failure of a target pipe that was heated and pressurized to Pressurized Water Reactor (PWR) conditions. Damage was measured in terms of crushing, bending, and failure. The results of the tests permitted the correlation between pipes of a certain size and the damage they could cause when impacting with a certain amount of known energy. These results were used to evaluate the pipe whip criteria in the Standard Review Plan 3.6.2-4. It was established that the criteria conditions did not fully represent the results obtained experimentally. An analysis procedure to model the pipe whip event was developed and used to establish the test matrix for the experimental program. This analytical procedure can also be used to predict deformation and rupture for postulated pipe whip scenarios. 17 refs.

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

1987-05-01

285

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

286

65. FIRE SUPPRESSION PIPES BEHIND FLAME BUCKET. PIPES TO UMBILICAL ...  

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

65. FIRE SUPPRESSION PIPES BEHIND FLAME BUCKET. PIPES TO UMBILICAL MAST IN LOWER LEFT CORNER; PIPES TO LAUNCHER IN UPPER LEFT CORNER; PIPES TO FLAME BUCKET IN LOWER RIGHT CORNER OF PHOTOGRAPH. POTABLE WATER PIPING IN UPPER RIGHT CORNER OF PHOTO. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

287

Pipe crawler with stabilizing midsection  

Microsoft Academic Search

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

W. T. Zollinger; R. C. Treanor

1994-01-01

288

Pipe crawler with stabilizing midsection  

Microsoft Academic Search

This invention is comprised of a pipe crawler 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

W. T. Zollinger; R. C. Treanor

2009-01-01

289

Pipe crawler with stabilizing midsection  

Microsoft Academic Search

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

William T. Zollinger; Richard C. Treanor

1994-01-01

290

Study of structurally efficient graphite-thermoplastic trapezoidal-corrugation sandwich and semisandwich panels  

NASA Astrophysics Data System (ADS)

The structural efficiency of compression-loaded trapezoidal-corrugation sandwich and semisandwich 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 semisandwich 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 3000 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.

1994-03-01

291

Polarized Raman spectroscopy of corrugated MBE grown GaAs (6¯3¯1¯) homoepitaxial films  

NASA Astrophysics Data System (ADS)

In this work, we present a Raman scattering study of GaAs layers grown on (6¯3¯1¯)-oriented substrates by molecular beam epitaxy. A set of samples whose morphology sustained different corrugation order were grown by MBE by varying the growth parameters such as temperature and As/Ga flux ratio. We employed polarized Raman spectroscopy using the backscattering configurations Z(XX) Z¯, Z(XY) Z¯ and Z(YY)Z¯. According to the calculated dipole selection rules both TO and LO phonons are allowed for backscattering from a perfect GaAs (6¯3¯1¯) crystal, but with the intensity of the TO phonon much larger than that of the LO phonon. However, it is found that the selection rules differ for corrugated samples. Besides, the TO/LO phonon resonances intensity ratio and the LO peak asymmetry depend on the corrugation order of the samples.

Espinosa-Vega, L. I.; Rodriguez, A. G.; Cruz-Hernandez, E.; Martinez-Veliz, I.; Rojas-Ramirez, J.; Ramirez-Lopez, M.; Nieto-Navarro, J.; Lopez-Lopez, M.; Mendez-Garcia, V. H.

2013-09-01

292

Density functional theory analysis of flexural modes, elastic constants, and corrugations in strained graphene  

NASA Astrophysics Data System (ADS)

Ab initio density functional theory has been used to analyze flexural modes, elastic constants, and atomic corrugations on single- and bi-layer graphene. Frequencies of flexural modes are sensitive to compressive stress; its variation under stress can be related to the anomalous thermal expansion via a simple model based in classical elasticity theory [P. L. de Andres, F. Guinea, and M. I. Katsnelson, Phys. Rev. BPRBMDO1098-012110.1103/PhysRevB.86.144103 86, 144103 (2012)]. Under compression, flexural modes are responsible for a long-wavelength rippling with a large amplitude and a marked anharmonic behavior. This is compared with corrugations created by thermal fluctuations and the adsorption of a light impurity (hydrogen). Typical values for the later are in the sub-Angstrom regime, while maximum corrugations associated to bending modes quickly increase up to a few Angstroms under a compressive stress, due to the intrinsic instability of flexural modes.

de Andres, P. L.; Guinea, F.; Katsnelson, M. I.

2012-12-01

293

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

NASA Astrophysics Data System (ADS)

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.

294

Abrasion resistant heat pipe  

DOEpatents

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

Ernst, D.M.

1984-10-23

295

Study of Compression-Loaded and Impact-Damaged Structurally Efficient Graphite-Thermoplastic Trapezoidal-Corrugation Sandwich and Semisandwich Panels.  

National Technical Information Service (NTIS)

The structural efficiency of compression-loaded trapezoidal-corrugation sandwich and semisandwich composite panels is studied to determine their weight savings potential. Sandwich panels with two identical face sheets and a trapezoidal corrugated core bet...

D. C. Jegley

1992-01-01

296

Oceanic corrugated surfaces and the strength of the axial lithosphere at slow spreading ridges  

NASA Astrophysics Data System (ADS)

We analyse the topography and gravity signature of 39 corrugated surfaces formed over the past 26 myrs in the footwall of axial detachment faults at the easternmost Southwest Indian Ridge. We show that these corrugated surfaces formed at intermediate melt supply and that their presently elevated topography, relative to adjacent non-corrugated seafloor, was mostly acquired at the end of their formation, at the "termination stage". This configuration, which also characterizes many off-axis corrugated surfaces in other oceans, suggests that the plate's flexural rigidity is very low during the formation of the corrugated surface, and increases significantly at the termination stage. We present a numerical model in which these variations in the axial plate's rigidity are explained by variable mechanical accommodation within the footwall of axial detachment faults, due to partial hydration of exhumed mantle material. We further propose that weak talc- coated shear zones developped in mantle-derived ultramafics due to interactions with Si-rich hydrous fluids derived from the alteration of gabbro intrusions drastically reduce the strength of the upper part of the brittle lithosphere in the detachment footwall. Based on this conceptual model, we predict that corrugated surfaces, with subdued dynamic topography, form preferentially when such talc-coated weak shear zones are frequent in the exhumed ultramafics. This requires that gabbro intrusions are sufficiently abundant to provide Si-rich metasomatic fluids but do not form a coherent rigid framework in the detachment's footwall. This hypothesis, which may be tested by drilling, is compatible with the Buck et al. (2005) model which links for the formation of long-lasting detachments at mid-ocean ridges to an intermediate supply of melt to the axial crust.

Cannat, M.; Lavier, L.; Sauter, D.; Escartin, J.

2008-12-01

297

Riser pipe elevator  

SciTech Connect

This patent describes a method for storing and retrieving a riser pipe, comprising the steps of: providing an upright annular magazine comprised of an inside annular wall and an outside annular wall, the magazine having an open top; storing the riser pipe in a substantially vertically oriented position within the annular magazine; and moving the riser pipe upwardly through the open top of the annular magazine at an angle to the vertical along at least a portion of the length of the riser pipe.

Bennett, W.; Jimenez, A.F.

1987-09-08

298

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

Microsoft Academic Search

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

Mohammad Reza Jafari Nasr; Ali Habibi Khalaj

2010-01-01

299

Casimir Force on a Surface with Shallow Nanoscale Corrugations: Geometry and Finite Conductivity Effects  

SciTech Connect

We measure the Casimir force between a gold sphere and a silicon plate with nanoscale, rectangular corrugations with a depth comparable to the separation between the surfaces. In the proximity force approximation (PFA), both the top and bottom surfaces of the corrugations contribute to the force, leading to a distance dependence that is distinct from a flat surface. The measured Casimir force is found to deviate from the PFA by up to 10%, in good agreement with calculations based on scattering theory that includes both geometry effects and the optical properties of the material.

Bao, Y. [Department of Physics, University of Florida, Gainesville, Florida 32611 (United States); Guerout, R.; Lussange, J.; Lambrecht, A. [Laboratoire Kastler-Brossel, CNRS, ENS, Universite Pierre et Marie Curie case 74, Campus Jussieu, F-75252 Paris Cedex 05 (France); Cirelli, R. A.; Klemens, F.; Mansfield, W. M.; Pai, C. S. [Bell Laboratories, Alcatel-Lucent, Murray Hill, New Jersey 07974 (United States); Chan, H. B. [Department of Physics, the Hong Kong University of Science and Technology (Hong Kong)

2010-12-17

300

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

301

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

NASA Astrophysics Data System (ADS)

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

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

2009-09-01

302

Smoke Production of Nonmetallic Pipes.  

National Technical Information Service (NTIS)

The smoke production of nonmetallic pipes was investigated using 'Test Method for Specific Optical Density of Smoke Generated by Solid Materials,' ASTM E 662. The pipe samples consisted of two epoxy resin glass reinforced pipes, two vinyl ester resin glas...

W. H. McLain L. Nash

1995-01-01

303

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

304

Insulated Pipe Clamp Design.  

National Technical Information Service (NTIS)

Thin wall large diameter piping for breeder reactor plants can be subjected to significant thermal shocks during reactor scrams and other upset events. On the Fast Flux Test Facility, the addition of thick clamps directly on the piping was undesired becau...

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

1980-01-01

305

Splayed mirror light pipes  

SciTech Connect

An expression is given for the transmission of the rectangular-section mirror light pipe. The expression is used to model throughputs for simulated solar conditions over a calender year. It is found that the splaying of a mirror light pipe results in a significant increase in throughputs particularly in winter months. (author)

Swift, P.D. [School of Physical Sciences, Dublin City University, Dublin 9 (Ireland)

2010-02-15

306

These Pipes Are "Happening"  

ERIC Educational Resources Information Center

The author is blessed with having the water pipes for the school system in her office. In this article, the author describes how the breaking of the pipes had led to a very worthwhile art experience for her students. They practiced contour and shaded drawing techniques, reviewed patterns and color theory, and used their reasoning skills--all while…

Skophammer, Karen

2010-01-01

307

Heat transfer pipe  

Microsoft Academic Search

A heat transfer pipe for use in a heat exchanger such as air conditioner, freezer and boiler is disclosed wherein grooves are formed in the inner wall surface of the pipe, which are by far finer in size than the grooves that have been provided for the purpose of increasing the heat transfer area in general, and slanting relative to

K. Fujie; M. Itoh; T. Innami; H. Kimura; W. Nakayama; T. Yanagida

1977-01-01

308

Heat transfer in pipes  

Microsoft Academic Search

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

T. Burbach

1985-01-01

309

Inspecting flexible pipe  

SciTech Connect

Construction characteristics of flexible pipe, including composite structure of alternating layers of material, polymer and gas permeation and structural prevention of explosive deformation (ED) are reviewed. The author contrasts bonded and nonbonded construction in order to relate flexible pipe's complex behavior to an inspection method.

Neffgen, J.M. (Pag-O-Flex A/S (NO))

1990-11-01

310

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

311

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

312

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

313

14-3: Design of an internal coupler to corrugated waveguide for high power gyrotrons  

Microsoft Academic Search

Modern high power produce power in high-order TE modes. These modes cannot be efficiently transported in a low loss transmission system, which is typically a corrugated waveguide. The current approach is to convert the TE mode to a Gaussian beam inside the tube and then use an external coupling unit to match the Gaussian beam to the HE11 mode in

Jeffrey M. Neilson; Philipp Borchard

2010-01-01

314

Effect of sleeper pitch on rail corrugation at a tangent track in vehicle hunting  

Microsoft Academic Search

The effect of sleeper pitch on the initiation and development of rail corrugation at tangent track is investigated using a numerical method in vehicle hunting. The numerical analysis considers a combination of Kalker's rolling contact theory with non-Hertzian form, linear frictional work model and the dynamics model of a half railway vehicle coupled with a tangent track. Kalker's theory is

Xuesong Jin; Xinbiao Xiao; Zefeng Wen; Zhongrong Zhou

2008-01-01

315

Effects of Mismatch Strain and Substrate Surface Corrugation on Morphology of Supported  

Microsoft Academic Search

Graphene monolayers supported on oxide substrates have been demonstrated with superior charge mobility and thermal transport for potential device applications. Morphological corrugation can strongly influence the transport properties of the supported graphene. In this paper, we theoretically analyze the morphological stability of a graphene monolayer on an oxide substrate, subject to van der Waals interactions and in-plane mismatch strains. First,

Monolayer Graphene; Zachary H. Aitken; Rui Huang

316

Effects of Mismatch Strain and Substrate Surface Corrugation on Morphology of Supported Monolayer Graphene  

Microsoft Academic Search

Graphene monolayers supported on oxide substrates have been demonstrated with superior charge mobility and thermal transport for potential device applications. Morphological corrugation can strongly influence the transport properties of the supported graphene. In this paper, we theoretically analyze the morphological stability of a graphene monolayer on an oxide substrate, subject to van der Waals interactions and in-plane mismatch strains. First,

Zachary H. Aitken; Rui Huang

2010-01-01

317

Multi-sheet corrugated tank construction for passive solar heating systems  

Microsoft Academic Search

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

Buckley

1984-01-01

318

An appropriate vacuum technology for manufacture of corrugated fique fiber reinforced cementitious sheets  

Microsoft Academic Search

This paper reports the experiences of making Portland cement based corrugated roof sheets with the reinforcement of a Colombian natural fiber, named fique. The sheets were manufactured by a vacuum forming process. The raw material components of the sheets are given. The average flexural load to failure reported 2875N\\/m at 14 curing days, which it is considered appropriate for a

S. Delvasto; E. F. Toro; F. Perdomo; R. Mejía de Gutiérrez

2010-01-01

319

Multiple Scattering Casimir Force Calculations: Layered and Corrugated Materials, Wedges, and Casimir-Polder Forces  

Microsoft Academic Search

Various applications of the multiple scattering technique to calculating Casimir energy are described. These include the interaction between dilute bodies of various sizes and shapes, temperature dependence, interactions with multilayered and corrugated bodies, and new examples of exactly solvable separable bodies.

Kimball A. Milton; Prachi Parashar; Jef Wagner; Ines Cavero-Pelaez

2009-01-01

320

Microwave pulses compressed in a quasi-optical resonator with corrugated mirror  

Microsoft Academic Search

A microwave pulse compressor, representing a three-mirror resonator supplied with a radiation beam reflected from a corrugated\\u000a mirror, was constructed and experimentally tested. A fivefold compression of microwave pulses with a 70% efficiency was obtained\\u000a in a 9-mm wavelength range.

Yu. Yu. Danilov; S. V. Kuzikov; V. G. Pavel’ev; Yu. I. Koshurinov; S. M. Leshchinsky

2001-01-01

321

Melting of a repulsive screened Coulomb system in two dimensions: Effect of corrugation  

NASA Astrophysics Data System (ADS)

By use of constant energy molecular dynamics simulations, we have investigated the melting and freezing transitions in a two-dimensional system consisting of a constant density of classical particles interacting with a repulsive screened Coulomb (Yukawa) potential. In particular, we have investigated the role of an incommensurate substrate corrugation potential of sixfold symmetry on these transitions by probing the temperature dependence of the bond orientational order parameter (?6) and the corresponding susceptibility (?6). Other physical quantities such as energy, diffusion constant, and the density of local topological defects have been monitored through the transition region. In the absence of a corrugation potential the system shows a sharp melting transition. In the presence of a corrugation potential the transition temperature increases and the transition becomes smoother. In contrast to the corrugation-free case we find a broad peak in ?6 above the transition temperature. We interpret this behavior in terms of the melting of a domain-wall solid. The detailed nature of this smooth transition depends on the degree of incommensurability. Relevance of these results to stage-2 graphite intercalation compounds is discussed.

Seong, Hyangsuk; Mahanti, S. D.; Sen, Surajit; Ça?in, Tahir

1992-10-01

322

Radiation Characteristics of Electromagnetic Eigenmodes at the Corrugated Interface of a Left-Handed Material  

Microsoft Academic Search

We study the radiation characteristics of electromagnetic surface waves at a periodically corrugated interface between a conventional and a negatively refracting (or left-handed) material. In this case, and contrary to the surface plasmon polariton in a metallic grating, surface plasmon polaritons may radiate on both sides of the rough interface along which they propagate. We find novel radiation regimes which

Mauro Cuevas; Ricardo A. Depine

2009-01-01

323

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

324

A new mechanism for negative refraction and focusing using selective diffraction from surface corrugation  

Microsoft Academic Search

Refraction at a smooth interface is accompanied by momentum transfer normal to the interface. We show that corrugating an initially smooth, totally reflecting, non-metallic interface provides a momentum kick parallel to the surface, which can be used to refract light negatively or positively. This new mechanism of negative refraction is demonstrated by visible light and microwave experiments on grisms (grating-prisms),

W. T. Lu; Y. J. Huang; P. Vodo; R. K. Banyal; C. H. Perry; S. Sridhar

2007-01-01

325

A new mechanism for negative refraction and focusing using selective diffraction from surface corrugation  

Microsoft Academic Search

Refraction at a smooth interface is accompanied by momentum transfer normal to the interface. We show that corrugating an initially smooth, totally reflecting, non-metallic interface provides a momentum kick parallel to the surface, which can be used to refract light negatively or positively. This new mechanism of negative refraction is demonstrated by visible light and microwave experiments on grisms (grating-prisms).

W. T. Lu; Y. J. Huang; P. Vodo; R. K. Banyal; C. H. Perry; S. Sridhar

2007-01-01

326

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

327

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 analytic models provide accurate predictions when failure initiation is controlled by

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

2006-01-01

328

Terahertz Surface Plasmon-Polariton Propagation and Focusing on Periodically Corrugated Metal Wires  

Microsoft Academic Search

In this Letter, we show how the dispersion relation of surface plasmon polaritons (SPPs) propagating along a perfectly conducting wire can be tailored by corrugating its surface with a periodic array of radial grooves. In this way, highly localized SPPs can be sustained in the terahertz region of the electromagnetic spectrum. Importantly, the propagation characteristics of these spoof SPPs can

Stefan A. Maier; Steve R. Andrews; L. Martín-Moreno; F. J. García-Vidal

2006-01-01

329

Effect of absorption on terahertz surface plasmon polaritons propagating along periodically corrugated metal wires  

Microsoft Academic Search

In this paper, a rigorous method for analyzing surface plasmon polaritons (SPPs) on a periodically corrugated metal wire has been formulated, based on a modal expansion of electromagnetic fields. Compared with the previous method, our method takes into account the finite conductivity of the wire as well as higher-order modes within the wire grooves in the expansion, thus is able

Linfang Shen; Xudong Chen; Yu Zhong; Krishna Agarwal

2008-01-01

330

Short pitch corrugation of railway tracks with wooden or concrete sleepers: An enigma solved?  

Microsoft Academic Search

British Railways (BR) in the 1970s observed an increased level of short pitch corrugation after the electrification of the West Coast main line, which involved (among other things) the change from wooden to concrete sleepers. Here, using a simple model for the two systems, we find a different sensitivity to lateral creepage, a doubled growth at the “pinned–pinned” resonance regime

Luciano Afferrante; Michele Ciavarella

2010-01-01

331

An analytical approach to study a special case of booted sleeper track rail corrugation  

Microsoft Academic Search

The present paper examines a specific kind of short pitch corrugation as observed on the low rail in some of the sharp bends that form part of a specific section of a railway line in the Bilbao area. The periodic irregularity appeared spontaneously when ballasted track was replaced by STEDEF slab track and separation between sleepers was changed from 600

Iosu Gómez; E. G. Vadillo

2001-01-01

332

A corrugated waveguide phase shifter and its use in HPM dual-reflector antenna arrays  

Microsoft Academic Search

An analysis, with computations and experimental verification, is given which shows that an axially compressible or extendable thin-wall corrugated metallic cylinder can be used as a phase shifter to achieve ±180° phase control. Employment of such a device in an array of high power microwave (HPM) dual-reflector antennas to achieve maximum in-phase array radiation is then briefly outlined

L. F. Libelo; C. M. Knop

1995-01-01

333

Analysis of scattering from cylinders with a periodically corrugated periphery using a current-model technique  

Microsoft Academic Search

A novel solution is presented for the problem of two-dimensional electromagnetic scattering from a circular cylinder with periodically corrugated circumference. The application of the Floquet formalism is effected by representing the incident field as a sum of fields, each one obeying a Floquet periodicity condition involving a different phase factor. Respective sets of fictitious sources, comprising rotationally periodic and properly

Amir Boag; Yehuda Leviatan; Alona Boag

1993-01-01

334

Optimum performance of a corrugated, collector-driven, irreversible carnot heat engine and absorption refrigerator  

Microsoft Academic Search

The technique of energetic optimization is employed to investigate the optimal performance of a corrugated, collector-driven, irreversible Carnot heat engine and an absorption refrigerator. A minimum operating parameter and a relation between the maximum overall efficiencies are obtained for the systems under consideration.

Süleyman Özkaynak

1997-01-01

335

Anomalous light reflection at the surface of a corrugated thin metal film  

Microsoft Academic Search

The process of excitation of surface electromagnetic waves (SEW's) in corrugated thin metal film is investigated theoretically and experimentally. The existence of an anomalous increase of the reflection coefficient is demonstrated. The excitation of long-range plasmons in thin metal films opens new possibilities for sensor applications

Ildar F. Salakhutdinov; Vladimir A. Sychugov; Alexander V. Tishchenko; Boris A. Usievich; Olivier Parriaux; Fedor A. Pudonin

1998-01-01

336

Heat exchange and hydraulic resistance of laser mirror cooling systems from corrugations  

NASA Astrophysics Data System (ADS)

The hydrodynamics and heat exchange of cooling systems based on corrugated inserts have been investigated analytically and experimentally. On the basis of the generalization of the data obtained, the fields of reasonable use of such systems for cooling laser mirrors have been determined. Recommendations for improving the characteristics of the above systems have been worked out.

Shanin, Yu. I.; Shanin, O. I.

2013-07-01

337

Simulation of the evolution of rail corrugation using a rotating flexible wheelset model  

Microsoft Academic Search

This paper presents a simulation tool designed for predicting the wear pattern on the running surface of the rails and for studying the evolution of rail corrugation after thousands of wheelset passages. This simulation tool implements a cyclic track model, a rotating flexible wheelset model, a wheel–rail contact model and a wear model. The vehicle–track system is modelled by using

Paloma Vila; Juan Fayos; Luis Baeza

2011-01-01

338

Tip orbitals and the atomic corrugation of metal surfaces in scanning tunneling microscopy  

Microsoft Academic Search

When atomic resolution is achieved, the scanning tunneling microscope (STM) image of a dense metal surface shows a giant amplitude, i.e., between one and two orders of magnitude larger than expected from an s-wave tip. To date, no satisfactory explanation has been given. Using our earlier nonperturbative formalism for the tunnel current, we reconsider the corrugation problem with a single

William Sacks

2000-01-01

339

Atrophy of corrugator supercilii muscle in a patient induced by the onabotulinum toxin injection.  

PubMed

Onabotulinum toxin has been used to treat a variety of headaches. We report a case of a 29-year-old woman who developed temporary and reversible atrophy of corrugator supercilii muscle after onabotulinum toxin (Botox, Allergan, Irvine, CA, USA) injection. To our best knowledge this has not been described in the literature before. PMID:22085341

Zhao, Chong-hao; Stillman, Mark

2011-11-15

340

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

341

Corrugated round fibers to improve cell adhesion and proliferation in tissue engineering scaffolds.  

PubMed

Optimal cell interaction with biomaterial scaffolds is one of the important requirements for the development of successful in vitro tissue-engineered tissues. Fast, efficient and spatially uniform cell adhesion can improve the clinical potential of engineered tissue. Three-dimensional (3-D) solid free form fabrication is one widely used scaffold fabrication technique today. By means of deposition of polymer fibers, scaffolds with various porosity, 3-D architecture and mechanical properties can be prepared. These scaffolds consist mostly of solid round fibers. In this study, it was hypothesized that a corrugated fiber morphology enhances cell adhesion and proliferation and therefore leads to the development of successful in vitro tissue-engineered constructs. Corrugated round fibers were prepared and characterized by extruding poly(ethylene oxide terephthalate)-co-poly(butylene terephthalate) (300PEOT55PBT45) block co-polymer through specially designed silicon wafer inserts. Corrugated round fibers with 6 and 10 grooves on the fiber surface were compared with solid round fibers of various diameters. The culture of mouse pre-myoblast (C2C12) cells on all fibers was studied under static and dynamic conditions by means of scanning electron microscopy, cell staining and DNA quantification. After 7days of culturing under static conditions, the DNA content on the corrugated round fibers was approximately twice as high as that on the solid round fibers. Moreover, under dynamic culture conditions, the cells on the corrugated round fibers seemed to experience lower mechanical forces and therefore adhered better than on the solid round fibers. The results of this study show that the surface architecture of fibers in a tissue engineering scaffold can be used as a tool to improve the performance of the scaffold in terms of cell adhesion and proliferation. PMID:23485858

Bettahalli, N M S; Arkesteijn, I T M; Wessling, M; Poot, A A; Stamatialis, D

2013-02-26

342

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

343

Pipe weld crown removal device  

Microsoft Academic Search

A device is provided for grinding down the crown of a pipe weld joining aligned pipe sections so that the weld is substantially flush with the pipe sections joined by the weld. The device includes a cage assembly comprising a pair of spaced cage rings adapted to be mounted for rotation on the respective pipe sections on opposite sides of

C. K. Sword; P. J. Sette

1992-01-01

344

Pipe weld crown removal device  

Microsoft Academic Search

This invention is comprised of a device that provides for grinding down the crown of a pipe weld joining aligned pipe sections so that the weld is substantially flush with the pipe sections joined by the weld. The device includes a cage assembly comprising a pair of spaced cage rings adapted to be mounted for rotation on the respective pipe

C. K. Sword; P. J. Sette

1991-01-01

345

Practical considerations in piping analysis  

Microsoft Academic Search

The conference proceedings contains 14 papers which consider innovative techniques to produce high quality work on time. Eight papers are abstracted separately. Topics covered include steamhammer in power plant piping, allowable pipe loads on rotating equipment nozzles, piping insulation, expansion joints, flanged connections, coal gasification combined cycle power plants, elimination of use of metallic expansion joints, piping engineering computer codes.

E. van Stijgeren; L. Krawzya; K. Steffens; J. Woodward

1982-01-01

346

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

347

Automated Ultrasonic Pipe Weld Inspection  

Microsoft Academic Search

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

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

348

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

349

Effective pipe coating takes care  

SciTech Connect

A discussion of the operations involved in the preparation of effective hot-enamel pipe coating covers the storage, drying, and cleaning of the pipe, including the segregation of pipe carried on the deck of ocean-going ships or barges so as to allow weathering to remove salt spray; application of primer coatings; melting and heating of enamel; application of the hot enamel coating; inspection; and storage of coated pipe, and concludes that the effectiveness of a hot-enamel pipe coating is a shared responsibility between the pipeline owner, pipe-coating materials manufacturer, and the pipe-coating contractor.

Polkinhorne, D.A.

1980-01-01

350

Accelerated Corrosion Test for Metal Drainage Pipes.  

National Technical Information Service (NTIS)

The study represents an attempt to develop an accelerated test which would assist the highway engineer in evaluating the usefulness of a new type of coated steel culvert. The test method was to be short in duration (in the order of days), and the results ...

J. D. Garber J. H. Lin

1987-01-01

351

Miniature pipe crawler tractor  

SciTech Connect

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

McKay, Mark D. (Idaho Falls, ID); Anderson, Matthew O. (Idaho Falls, ID); Ferrante, Todd A. (Westerville, OH); Willis, W. David (Idaho Falls, ID)

2000-01-01

352

Miniature pipe crawler tractor  

SciTech Connect

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

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

2000-03-14

353

Internal pipe attachment mechanism.  

National Technical Information Service (NTIS)

This invention is comprised of 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...

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

1993-01-01

354

Corrosion of Underground Pipe.  

National Technical Information Service (NTIS)

Corrosion of underground steel pipe was explored through a literature survey and experimental investigation. The changes in solution parameters which occur during cathodic protection and their effect on corrosion were examined. The variation in pH was clo...

K. Kelley N. G. Thompson

1983-01-01

355

Pipe Heat Transfer Calculation.  

National Technical Information Service (NTIS)

This is a group of computer programs to determine heat transfer of multiple pipe systems as well as to evaluate economics of underground heat distribution systems. ...Software Description: The system is written in the FORTRAN V programming language for im...

1973-01-01

356

The pipes of pan.  

PubMed

The pipes of pan is the crowning achievement of Pablo Picasso's neoclassical period of the 1920s. This monumental canvas depicts a mythological Mediterranean scene in which two sculpted classical giants stare out, seemingly across the centuries, toward a distant and lost Arcadia. Picasso was influenced by Greco-Roman art during his travels in Italy, and his neoclassical works typically portray massive, immobile, and pensive figures. Pan and his pipes are taken directly from Greek mythological lore by Picasso and placed directly into 20th century art. He frequently turned to various mythological figures throughout his metamorphosing periods. The Pipes of Pan was also influenced by the painter's infatuation with the beautiful American expatriate Sara Murphy, and the finished masterpiece represents a revision of a previously conceived neoclassical work. The Pipes of Pan now hangs in the Musee Picasso in Paris. PMID:15574231

Chalif, David J

2004-12-01

357

Inexpensive headwall for culverts  

SciTech Connect

A headwall retainer structure is described comprised of: (a) two sidewalls in spaced apart parallel alignment, each having a substantially U-shaped configuration with downwardly directed opposed leg portions and having horizontally disposed lower edge extremities, a U-shaped opening centered in the sidewall and having a semi-circular upper boundary which merges tangentially with straight vertical side boundaries constituting facing interior edge extremities of the leg portions, and an outer perimeter having an upper section disposed above the opening, and vertical side sections constituting exterior edge extremities of the leg portions, (b) a transverse wall extending between the perimeter edges of the two sidewalls, thereby defining with the sidewalls a chamber which is open at the lower edge extremities of the leg portions and within the U-shaped opening, (c) a filling aperture in the upper section of the transverse wall, and (d) spacer struts extending perpendicularly between the sidewalls adjacent the U-shaped opening and adjacent the lower extremities of the legs. The retainer structure has a first vertical plane of symmetry that perpendicularly intersects the sidewalls midway between the leg portions.

Roscoe, D.

1988-02-09

358

Structures, Culverts, and Tunnels.  

National Technical Information Service (NTIS)

Contents: Elementalistic and Holistic Views for Evaluation and Design of Structure Movement Systems; High-Load Elastomeric Bridge Bearings; Corrosion and Fatigue Resistance Study of Aluminum Bridge Deck; New Safety-Based Checking Procedure for Overloads o...

1996-01-01

359

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

360

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

361

Theoretical model of a planar waveguide refractive index sensor assisted by a corrugated long period metal grating  

Microsoft Academic Search

A theoretical model of a novel planar integrated refractive index sensor based on surface plasmon-polariton (SPP) excitation with a corrugated metal long period grating (LPG) is presented and comprehensively investigated. The main principle of the operation this device is based on co-directional energy transfer by means of a corrugated metal LPG between a p-polarized guided mode propagating in a waveguide

Galina Nemova; Raman Kashyap

2008-01-01

362

Specific features of mode spectrum of planar structures with two-dimensional Bragg corrugation (theory and “cold” experiment)  

Microsoft Academic Search

Electrodynamic properties of two-dimensional-periodic Bragg structures of planar geometry are theoretically analyzed within\\u000a the framework of the geometrical-optics approximation. Specific features of two-dimensional structures with different profiles,\\u000a such as two-dimensional sinusoidal and “chess-board” corrugation and corrugation in the form of rectangular grooves, are studied.\\u000a “Cold” testing of the Bragg structures in frequency ranges of 60 and 75 GHz is performed.

N. S. Ginzburg; G. G. Denisov; S. V. Kuzikov; N. Yu. Peskov; A. S. Sergeev; V. Yu. Zaslavsky; A. V. Arzhannikov; P. V. Kalinin; S. P. Sinitsky; M. Tumm

2005-01-01

363

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

364

Short-pitch rail corrugation: A possible resonance-free regime as a step forward to explain the “enigma”?  

Microsoft Academic Search

Rail corrugation has been noticed at least for 100 years, but (particularly short pitch one in the range 20–80mm) has been considered an enigma because measured corrugation wavelength did not relate well with wear-instability models. The apparently large number of governing parameters has resulted in many independent efforts to generate models, which do not entirely correspond to the collected experimental

L. Afferrante; M. Ciavarella

2009-01-01

365

Nano and Micro-Corrugations in Photo-Aligned Polymer Thin-Films; Correlations Between Topologies and Directional Light Scattering  

Microsoft Academic Search

Isotropic and anisotropic nano- and micro-corrugations in polymer thin-films are shown to be independently tunable via photo-controlled diffusion of liquid crystalline pre-polymer molecules on substrate surfaces. Amplitude and shape of MC-topologies are quantitatively correlated with light scattering. Scattering from monomer corrugated (MC)-topologies is correlated with the averaged power spectral density (PSD) function of MC-height fluctuations and shown to be proportional

Mohammed Ibn-Elhaj; Martin Schadt

2003-01-01

366

Corrugated silicon platelet feed horn array for CMB polarimetry at 150 GHz  

NASA Astrophysics Data System (ADS)

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, < -20 dB return loss from 120 GHz to 170 GHz, < -25 dB side lobes and < -23 dB cross-polarization. We are currently fabricating a 50mm diameter array with 84 horns consisting of 33 Si platelets as a prototype for the SPTpol and ACTpol telescopes. Our fabrication facilities permit arrays up to 150mm in diameter.

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

2010-07-01

367

Proposal and analysis of artificial dielectric lens with metallic corrugated structures for terahertz wave band  

NASA Astrophysics Data System (ADS)

Optical devices for the terahertz wave band are being developed now and require better designs. This paper proposes an artificial dielectric lens with metallic corrugated structures for the terahertz wave band. A periodic analysis model extracted from the full model by assuming periodicity confirms the phase delay, which produces the focusing effect. Full model analysis also confirms the focusing effect. The full model analysis also confirms that the focusing length is longer as the spacing of corrugated baffles is wider. The focusing length is longer the metallic groove width is wider. The focusing length is longer as the groove depth is shallower. The lens shape without grooves does not produce the focusing effect. The results of the full model analysis are qualitatively consistent with those of the periodic model ones. This implies that the design for an exact size lens is possible by using the periodic model.

Konno, Takuya; Suzuki, Takahiro; Young, John C.; Saigusa, Mikio; Takano, Keisuke; Kitahara, Hideaki; Hangyo, Masanori; Suzuki, Takehito

2012-12-01

368

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

NASA Astrophysics Data System (ADS)

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

Ilias, H.

1999-11-01

369

Dynamic and spatial behavior of a corrugated interface in the driven lattice gas model  

Microsoft Academic Search

The spatiotemporal behavior of an initially corrugated interface in the two-dimensional driven lattice gas (DLG) model with attractive nearest-neighbors interactions is investigated via Monte Carlo simulations. By setting the system in the ordered phase, with periodic boundary conditions along the external field axis. i.e. horizontal, and open along the vertical directions respectively, an initial interface was imposed, that consists in

Gustavo P. Saracco; Ezequiel V. Albano

2010-01-01

370

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

371

A Compact Integrated Planar-Waveguide Refractive-Index Sensor Based on a Corrugated Metal Grating  

Microsoft Academic Search

In this paper, a theoretical model of a new planar integrated surface plasmon-polariton (SPP)-excitation-based refractive-index sensor is presented and comprehensively investigated. The main principle of operation of this device is based on energy transfer by means of a corrugated metal grating between a p-polarized guided mode propagating in a waveguide layer and the SPP propagating in the opposite direction in

Galina Nemova; Raman Kashyap

2007-01-01

372

An investigation into rail corrugation due to micro-slip under multiple wheel\\/rail interactions  

Microsoft Academic Search

The formation of short pitch corrugation on the railhead is studied by using an approach combining wheel\\/track dynamics, contact mechanics and wear. Multiple wheel\\/rail interactions are taken into account in the wheel\\/track dynamics. A quasi-static method based on a two-dimensional contact model is used to solve the unsteady rolling contact problem where the normal contact force and the surface curvature

T. X. Wu; D. J. Thompson

2005-01-01

373

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

Microsoft Academic Search

Two-phase closed thermosiphons are highly efficient heat-transfer elements with applications in terrestrial heat-transport and heat-recovery systems. In this paper, a corrugated copper tube was used as the container of the thermosiphons and distilled water was used as the working fluid. The influences of the liquid charge ratio and inclination angle on the heat-transfer performance were studied. It was found that

K. Negishi; K. Kaneko; T. Matsuoka; M. Hirashima; Y. Nishikawa; M. Taguchi

1991-01-01

374

Membranes fabricated with a deep singel corrugation for package stress reduction and residual stress relief  

Microsoft Academic Search

Thin square membranes including a deep circular corrugation are realized and tested for application in a strain-based pressure sensor. Package-induced stresses are reduced and relief of the residual stress is obtained, resulting in a large pressure sensitivity and a reduced temperature sensitivity. Finite element method simulations were carried out, showing that the pressure-deflection behaviour of the structure is close to

V L Spieringt; S. Bouwstra; J. F. Burger; M. C. Elwenspoek

1993-01-01

375

Quantum study of oriented NO scattering from Ag(111): orientational steering and effects of surface corrugation  

Microsoft Academic Search

We present quantum calculations of oriented NO scattering from a corrugated Ag(111) surface, based on the potential energy surfaces of DePristo and Alexander [J. Chem. Phys. 94 (1991) 8454]. A time-resolved analysis of the NO-axis distribution reveals significant reorientation as the molecule reaches the repulsive wall of the interaction, even when normal energy is 3–4 times larger than the well

Didier Lemoine; Thierry Duhoo

1998-01-01

376

Terahertz Surface Plasmon-Polariton Propagation and Focusing on Periodically Corrugated Metal Wires  

Microsoft Academic Search

In this letter we show how the dispersion relation of surface plasmon\\u000apolaritons (SPPs) propagating along a perfectly conducting wire can be tailored\\u000aby corrugating its surface with a periodic array of radial grooves. In this\\u000away, highly localized SPPs can be sustained in the terahertz region of the\\u000aelectromagnetic spectrum. Importantly, the propagation characteristics of these\\u000aspoof SPPs can

Stefan A. Maier; Steve R. Andrews; L. Martín-Moreno; F. J. García-Vidal

2006-01-01

377

Design and implementation of a novel CMOS MEMS condenser microphone with corrugated diaphragm  

Microsoft Academic Search

This study reports a CMOS-MEMS condenser microphone implemented using the standard thin films stacking of 0.35?m UMC CMOS 3.3\\/5.0V logic process, and followed by post-CMOS micromachining steps without introducing any special materials. The corrugated diaphragm for microphone is designed and implemented using the metal layer to reduce the influence of thin film residual stresses. Moreover, silicon substrate is employed to

Chien-Hsin Huang; Ming-Han Tsai; Chien-Hsing Lee; Tsung-Min Hsieh; Jhyy-Cheng Liou; Li-Che Chen; Ming-Chuen Yip; Weileun Fang

2011-01-01

378

Preliminary Analysis on Effect of Sleeper Pitch on Rail Corrugation at a Curved Track  

Microsoft Academic Search

This paper investigates the effect of sleeper pitch on the initiation and development of rail corrugation at a curved track\\u000a when a railway vehicle passes through the curved track using a numerical method. The numerical method considers a combination\\u000a of Kalker’s rolling contact theory with non-Hertzian form, a linear frictional work model and a dynamics model of a half railway

Xuesong Jin; Zefeng Wen; Qiyue Liu; Zhongrong Zhou

379

Treatment Outcomes of Auricular Hematoma Using Corrugated Rubber Drains: A Pilot Study  

PubMed Central

Background: Hematoma of the auricle which is a collection of blood beneath the perichondrial layer of the pinna usually poses a challenge to the otolaryngologist due to its high rate of recurrence after treatment and lack of appropriate material for use as stitch dressing especially, in the developing world. This is a Pilot study in which corrugated rubber drain was used as a stitch dressing after routine incision and drainage (I and D) in patients who presented with auricular hematoma. Aim: To determine the effectiveness of corrugated rubber drain in the treatment of auricular hematoma. Subjects and Methods: A total of seven patients were seen within a 2 year period in an ENT Ear, nose and throat clinic. Two patients had simple I and D done, one patient had suturing of the auricle between improvised plastic material used for stitch dressing after I and D, while four patients had I and D done and subsequently, a corrugated rubber drain was used as the stitch dressing. Results: Two patients treated with simple I and D had recurrence of hematoma, the patient treated with improvised plastic material had pressure necrosis of areas of the pinna which however improved when dressing was removed as soon as symptoms were noticed 2 days post-operatively. Four patients who had I and D and subsequent use of rubber-drain as stitch dressing, had un-eventful recoveries. Conclusion: Corrugated rubber tubing drains which are readily available in a developing country like ours has been found very useful as stitch dressing in the management of auricular hematoma.

Okolugbo, NE

2013-01-01

380

Design of conical corrugated feed horns for wide-band high-frequency applications  

Microsoft Academic Search

This paper presents a new analytical procedure for the design of the conical corrugated feed horns used in the millimeter and submillimeter wavelength range, which could achieve wide-band single-mode operation and wide-band, low return-loss impedance matching simultaneously. A test model of the feed horn designed using this procedure displayed excellent performance, and agreed well with the theoretical predictions

Xiaolei Zhang

1993-01-01

381

A new mechanism for negative refraction and focusing using selective diffraction from surface corrugation  

Microsoft Academic Search

Refraction at a smooth interface is accompanied by momentum transfer normal\\u000ato the interface. We show that corrugating an initially smooth, totally\\u000areflecting, non-metallic interface provides a momentum kick parallel to the\\u000asurface, which can be used to refract light negatively or positively. This new\\u000amechanism of negative refraction is demonstrated by visible light and microwave\\u000aexperiments on grisms (grating-prisms).

W. T. Lu; Y. J. Huang; P. Vodo; R. K. Banyal; C. H. Perry; S. Sridhar

2007-01-01

382

Ultimate strength of girders with trapezoidally corrugated webs under patch loading  

Microsoft Academic Search

Ultimate strength of steel plate girders with trapezoidally corrugated webs under patch loading is studied using a non-linear finite element method. Effect of large deflection is taken into account and a von Mises material either without strain hardening (elastic-perfectly plastic), or with strainhardening obeying Ramberg-Osgood's equation, is assumed. The following factors that influence the ultimate strength are investigate (1) strainhardening

R. Luo; B. Edlund

1996-01-01

383

Slow-light regime and critical coupling in highly multimode corrugated waveguides  

Microsoft Academic Search

Large and periodically corrugated optical waveguide structures are shown to possess specific modal regimes of slow-light propagation that are easily attainable. The very multimode nature of the coupling is studied by em- ploying coupled-mode theory and the plane-wave expansion method. Given a large enough light cone, associ- ated with a surrounding medium with low enough refractive index, we notably identify

H. Kurt; H. Benisty; T. Melo; O. Khayam; C. Cambournac

2008-01-01

384

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

385

Loop heat pipe radiator  

SciTech Connect

This paper describes the design and testing of a Loop Heat Pipe Radiator (LHPR) which was developed as an alternative to state-of-the-art axially-grooved heat pipes for space-based heat rejection which would be usable with tubing made of aluminum foil covered with a carbon-epoxy composite. The LHPR had an aluminum envelope and a polymer wick, and used ammonia as a working fluid. It was 4 meters long with a mass of 1.4 kg. The LHPR transported 500 watts at a 2.3 meter adverse inclination and 1500 watts when horizontal. This non-optimized LHPR had a 3000 watt-meter capability, which is four times greater than an axially-grooved heat pipe of similar power-handling capability and mass. In addition to a higher power handling capability, the LHPR has a much higher capillary margin than axially-grooved pipes. That high capillary margin simplifies ground testing in a 1-g environment by reducing the need for the careful levelling and vibration reduction required by axially-grooved pipes. {copyright} {ital 1996 American Institute of Physics.}

Sarraf, D.B.; Gernert, N.J. [Thermacore, Inc., 780 Eden Rd., Lancaster, Pennsylvania (United States)

1996-03-01

386

Molecular dynamics simulation of atomic-scale frictional behavior of corrugated nano-structured surfaces  

NASA Astrophysics Data System (ADS)

Surface morphology is one of the critical parameters that affect the frictional behavior of two contacting bodies in relative motion. It is important because the real contact area as well as the contact stiffness is dictated by the micro- and nano-scale geometry of the surface. In this regard, the frictional behavior may be controlled by varying the surface morphology through nano-structuring. In this study, molecular dynamics simulations were conducted to investigate the effects of contact area and structural stiffness of corrugated nano-structures on the fundamental frictional behavior at the atomic-scale. The nano-structured surface was modeled as an array of corrugated carbon atoms with a given periodicity. It was found that the friction coefficient of the nano-structured surface was lower than that of a smooth surface under specific contact conditions. The effect of applied load on the friction coefficient was dependent on the size of the corrugation. Furthermore, stiffness of the nano-structure was identified to be an important variable in dictating the frictional behavior.

Kim, Hyun-Joon; Kim, Dae-Eun

2012-06-01

387

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

SciTech Connect

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

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

1992-01-01

388

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.

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

2007-01-01

389

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

NASA Astrophysics Data System (ADS)

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

Yuan, Hong

2008-06-01

390

Pipe Clamp Effects on Thin-Walled Pipe Design.  

National Technical Information Service (NTIS)

Clamp induced stresses in FFTF piping are sufficiently large to require structural assessment. The basic principles and procedures used in analyzing FFTF piping at clamp support locations for compliance with ASME Code rules are given. Typical results from...

M. R. Lindquist

1980-01-01

391

Cemented pipe-in-pipe casing strings solve field problems  

SciTech Connect

A severe problem in old producing wells in high pressure areas is casing collapse. To solve it, tests were run on the feasibility of cementing smaller casing inside the larger, deformed pipe. Results were surprising. The collapse resistance of a pipe-in-pipe combination was at least 15 to 30% greater than API specifications and, even when the outer pipe was deformed, resistance was more than sufficient. 4 refs.

Burkowsky, M.; Ott, H.P.; Schillinger, H.

1981-10-01

392

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

393

Piping systems physical benchmarks  

SciTech Connect

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

Bezler, P.; Subudhi, M.

1985-01-01

394

Composite drill pipe  

DOEpatents

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

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

2008-12-02

395

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

396

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

397

Heat pipes and use of heat pipes in furnace exhaust  

SciTech Connect

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

398

Effect of discrete track support by sleepers on rail corrugation at a curved track  

NASA Astrophysics Data System (ADS)

The paper investigates into the effect of discrete track support by sleepers on the initiation and development of rail corrugation at a curved track when a railway vehicle passes through using a numerical method. The numerical method considers a combination of Kalker's rolling contact theory with non-Hertzian form, a linear frictional work model and a dynamics model of a half railway vehicle coupled with the curved track. The half-vehicle has a two-axle bogie and doubled suspension systems. It is treated as a full dynamic rigid multi-body model. In the track model, an Euler beam is used to model the rail, and the discrete track support by sleepers moving backward with respect to the vehicle running direction is considered to simulate the effect of the discrete sleeper support on the wheels/rails in rolling contact when the vehicle moves on the track. The sleeper is treated as a rigid body and the ballast bed is replaced with equivalent mass bodies. The numerical analysis exams in detail the variations of wheel/rail normal loads, the creepages, and the rail wear volume along the curved track. Their variations are much concerned with the discrete track support. The numerical results show that the discrete track support causes the fluctuating of the normal loads and creepages at a few frequencies. These frequencies comprise the passing frequency of the sleepers and the excited track resonant frequencies, which are higher than the sleeper passing frequency. Consequently, rail corrugation with several wavelengths initiates and develops. Also the results show that the contact vibrating between the curved rails and the four wheels of the same bogie has different frequencies. In this way, the different key frequencies to be excited play an important role in the initiation and development of curved rail corrugation. Therefore, the corrugations caused by the four wheels of the same bogie present different wavelengths. The paper shows and discusses the depths of the initial corrugations caused by the four wheels of the same bogie, at the entering transition curve, the circle curve and the exit transition curve of the curved track, respectively.

Jin, X. S.; Wen, Z. F.

2008-08-01

399

Preventing and Thawing Frozen Pipes  

MedlinePLUS

... Thunderstorm Tornado Tsunami Volcano Water Safety Wildfire Winter Storm Preventing and Thawing Frozen Pipes Protect Your Pets ... a Disaster or Emergency › Types of Emergency › Winter Storm › Preventing and Thawing Frozen Pipes Preventing and Thawing ...

400

Stresses in District Heating Pipes.  

National Technical Information Service (NTIS)

This report studies the possibilities to introduce new, higher, norms for the maximum stresses allowed in hot water pipes with a low number of complete temperature cycles. Suggestions for new criteria are presented for pipes of various design. (ERA citati...

S. Andersson S. Andersson D. Olofsson

1984-01-01

401

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,

402

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

403

Adjustable-angle pipe fitting  

DOEpatents

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

Kronberg, J.W.

1991-01-01

404

Adjustable-angle pipe fitting  

DOEpatents

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

Kronberg, J.W.

1991-12-31

405

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

NASA Astrophysics Data System (ADS)

In this study, two dimensional heat/mass transfer characteristics and flow features were investigated in a rectangular wavy duct with various corrugation angles. The test duct had a width of 7.3 mm and a large aspect ratio of 7.3 to simulate two dimensional characteristics. The corrugation angles used were 100°, 115°, 130°, and 145°. Numerical analysis using the commercial code FLUENT, was used to analyze the flow features. In addition, the oil-lamp black method was used for flow visualization. Local heat/mass transfer coefficients on the corrugated walls were measured using a naphthalene sublimation technique. The Reynolds number, based on the duct hydraulic diameter, was varied from 700 to 5,000. The experimental results and numerical analysis showed interesting and detailed features in the wavy duct. Main flow impinged on upstream of a pressure wall, and the flow greatly enhanced heat/mass transfer. On a suction wall, however, flow separation and reattachment dominantly affected the heat/mass transfer characteristics on the wall. As the corrugation angle decreased (it means the duct has more sharp turn), the region of flow stagnation at the front part of the pressure wall became wider. Also, the position of flow reattachment on the suction wall moved upstream as the corrugation angle decreased. A high heat transfer rate appeared at the front part of the pressure wall due to main-flow impingement, and at the front part of the suction wall due to flow reattachment. The high heat/mass transfer region by the main-flow impingement and the circulation flow induced at a valley between the pressure and suction walls changed with the corrugation angle and the Reynolds number. As the corrugation angle decreased, the flow in the wavy duct changed to transition to turbulent flow earlier.

Kwon, Hyun Goo; Hwang, Sang Dong; Cho, Hyung Hee

2008-12-01

406

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

SciTech Connect

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

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

1990-01-01

407

Corrosion of Copper Pipes  

Microsoft Academic Search

Rapid pitting of the walls of copper pipes used in plumbing has resulted in several controversial overtones. The results of a study of the problem in southern California are now available in this article and should benefit the water purveyor, who is, after all, responsible for taking reasonable measures to prevent unnecessary corrosion to copper service lines

Henry Cruse; Richard D. Pomeroy

1974-01-01

408

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

409

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

NASA Astrophysics Data System (ADS)

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.; Christou, M. A.

2011-11-01

410

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

411

Botulinum toxin A treatment of overactive corrugator supercilii in thyroid eye disease  

PubMed Central

BACKGROUND/AIM—Patients with thyroid eye disease with upper eyelid retraction often develop overaction of the accessory muscles of eyelid closure, the glabellar muscles corrugator supercilii and procerus. The resultant glabellar furrowing (frown lines) contributes to the typical thyroid facies. The aim of this study was to evaluate the use of botulinum toxin A reversible chemodenervation of the glabellar muscles as adjunctive treatment in the rehabilitation of patients with thyroid eye disease.?METHODS—14 patients (13 females) ages 39-76 years (mean 52) with inactive thyroid eye disease and associated medial eyebrow ptosis and prominent glabellar frown lines were recruited. All patients had a history of upper eyelid retraction. Each patient was treated with a single botulinum toxin injection (Dysport 0.2 ml, 40 units) into each corrugator supercilii and sometimes procerus muscles as an outpatient procedure. The effectiveness and acceptability of the treatment was assessed clinically and from a patient questionnaire.?RESULTS—The injections were tolerated by 13/14 (93%) patients. There was resultant flattening of the glabellar region and improvement of medial eyebrow contour in all patients, with onset of paralysis within 1 week. All patients reported a subjective improvement in appearance. Side effects included one patient (7%) with reversible partial ptosis. The beneficial effect lasted 4-6 months, with a gradual return of function. Repeat treatment was indicated where there was persistent upper eyelid retraction and protractor overaction.?CONCLUSION—Botulinum toxin A chemodenervation of the glabellar muscles in these patients was effective and acceptable. Chemodenervation should be considered in the rehabilitation of patients with thyroid eye disease where there is upper eyelid retraction and overacting protractors resulting in a thyroid frown. Once the eyelid retraction has been successfully treated by surgery, the need for further glabella muscle chemodenervation is considerably reduced.?? Keywords: botulinum toxin A; corrugator supercilii; frown lines; thyroid eye disease

Olver, J.

1998-01-01

412

Importance of the Darrieus-Landau instability for strongly corrugated turbulent flames  

NASA Astrophysics Data System (ADS)

The renormalization ideas of self-similar dynamics of a strongly turbulent flame front are applied to the case of a flame with realistically large thermal expansion of the burning matter. In that case a flame front is corrugated both by the external turbulence and by the intrinsic flame instability (the Darrieus-Landau instability). The analytical formulas for the velocity of flame propagation are obtained. It is demonstrated that the flame instability is of principal importance when the maximal hydrodynamic length scale is much larger than the cutoff wavelength of the instability, provided the turbulent intensity is not too high.

Bychkov, Vitaly

2003-12-01

413

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

SciTech Connect

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

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

1991-01-01

414

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

NASA Astrophysics Data System (ADS)

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 is 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.

2012-10-01

415

Radiation characteristics of electromagnetic eigenmodes at the corrugated interface of a left-handed material.  

PubMed

We study the radiation characteristics of electromagnetic surface waves at a periodically corrugated interface between a conventional and a negatively refracting (or left-handed) material. In this case, and contrary to the surface plasmon polariton in a metallic grating, surface plasmon polaritons may radiate on both sides of the rough interface along which they propagate. We find novel radiation regimes which provide an indirect demonstration of other unusual phenomena characteristic of electromagnetic wave propagation in left-handed materials, such as negative refraction or backward wave propagation. PMID:19792827

Cuevas, Mauro; Depine, Ricardo A

2009-08-25

416

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

NASA Astrophysics Data System (ADS)

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

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

2000-02-01

417

Unsteady mixed convective flow and heat transfer in a vertical corrugated channel with composite porous media  

NASA Astrophysics Data System (ADS)

An unsteady mixed convective flow and heat transfer in a vertical corrugated channel containing porous and fluid layers are considered. The equations of momentum and energy are solved under appropriate boundary and interface conditions with the assumption that the solution consists of a mean part and a perturbed one. The exact solutions are obtained in the long-wave approximation. Separate solutions are matched at the interface with the use of suitable matching conditions. The effects of pertinent parameters, such as the Grashof number, viscosity ratio, width ratio, conductivity ratio, frequency, and the wave parameter on the flow field and heat transfer characteristics are studied.

Umavathi, J. C.; Shekar, M.

2013-07-01

418

Mechanically Tunable Microbend Optical Fiber Gratings Using Corrugated Rubber and Uniformly Arrayed Metal Wire  

NASA Astrophysics Data System (ADS)

Mechanically tunable microbend optical fiber gratings using a corrugated rubber plate and an arrayed metal wire are proposed. With the variation in grating length by the elongation and constriction of the rubber plate, which is controlled by a micrometer adjuster, the resonant wavelength is linearly shifted within a given wavelength range. While the variation in the grating length reaches 3.2 mm, the resonant wavelength in the C-band shifts to a longer wavelength as large as 50 nm. This method provides a simple, accurate, and cost-effective tuning function to devices based on mechanically formed long-period fiber gratings (MLPFGs).

Sohn, Kyung Rak

2007-08-01

419

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

420

Plastic pipe testing techniques  

Microsoft Academic Search

As gas-distribution companies increasingly install polyethylene plastic piping, both the users and the producers of polyethylene will need to develop methods to predict the plastic's service-life expectancy and to determine the causes of any system failures that may occur. One particularly promising method is multipoint testing combined with improved failure-analysis techniques. Variants of this method include ASTM Method D2837, the

De Blieu

2009-01-01

421

The Effects of Road Crossings on Prairie Stream Habitat and Function  

Microsoft Academic Search

Improperly designed stream crossing structures may alter the form and function of stream ecosystems and habitat and prohibit the movement of aquatic organisms. Stream sections adjoining five concrete box culverts, five low-water crossings (concrete slabs vented by one or multiple culverts), and two large, single corrugated culvert vehicle crossings in eastern Kansas streams were compared to reference reaches using a

Wesley W. Bouska; Timothy Keane; Craig P. Paukert

2010-01-01

422

Experimenting with a ``Pipe'' Whistle  

NASA Astrophysics Data System (ADS)

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 allows students in a physics of music or introductory physics course to study an example of an ``edge tone'' device that produces discrete sound frequencies. From their textbooks, students likely know about standing waves produced by pipes or strings, as well as the resonant frequencies for open and closed pipes. To go a bit further, they can also learn how the frequency of the sound wave depends on the orifice-to-edge distance of the wind instrument.

Stafford, Olga

2012-04-01

423

Request for Proposal 77. Horizontal Pipe Racker.  

National Technical Information Service (NTIS)

A pipe handling system will be required on the Mohole drilling platform for storing and handling a maximum quantity of 39,000 feet of drill pipe and 19,000 feet of riser pipe. An automated pipe racking system was required as an integral part of the pipe h...

1965-01-01

424

High Toughness ERW Pipes for Arctic Use.  

National Technical Information Service (NTIS)

Recent progress of ERW pipe manufacturing technology has made it possible for ERW pipes to substitute UOE and stainless pipes in several fields. In order to develop ERW pipe available for line pipe with high toughness at low temperature, the fundamental s...

T. Shimomura T. Takamura S. Ishiro T. Sugayoshi Y. Nagahama

1987-01-01

425

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

NASA Astrophysics Data System (ADS)

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

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

2003-06-01

426

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

427

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

428

One-dimensional corrugation of the h-BN monolayer on Fe(110).  

PubMed

We report on a new nanopatterned structure represented by a single atomic layer of hexagonal boron nitride (h-BN) forming long periodic waves on the Fe(110) surface. The growth process and the structure of this system are characterized by X-ray absorption (XAS), core-level photoemission spectroscopy (CL PES), low-energy electron microscopy (LEEM), microbeam low-energy electron diffraction (?LEED), and scanning tunneling microscopy (STM). The h-BN monolayer on Fe(110) is periodically corrugated in a wavy fashion with an astonishing degree of long-range order, periodicity of 2.6 nm, and the corrugation amplitude of ?0.8 Å. The wavy pattern results from a strong chemical bonding between h-BN and Fe in combination with a lattice mismatch in either [111] or [111] direction of the Fe(110) surface. Two primary orientations of h-BN on Fe(110) can be observed corresponding to the possible directions of lattice match between h-BN and Fe(110), with approximately equal area of the boron nitride domains of each orientation. PMID:22185488

Vinogradov, N A; Zakharov, A A; Ng, M L; Mikkelsen, A; Lundgren, E; Mårtensson, N; Preobrajenski, A B

2012-01-11

429

Adhesive contact between a graphene sheet and a nano-scale corrugated surface  

NASA Astrophysics Data System (ADS)

Adhesive contacts between graphene sheets and corrugated surfaces are investigated. It is found that the final configuration between the graphene sheet and the substrate depends not only on the surface roughness of the substrate, but also on the length of graphene. A continuous transition, rather than a recent observation of ‘snap-through’ transition, is exhibited in our study. For a graphene sheet with a fixed length, it is easy to fully conform to the substrate of small roughness. Otherwise, the graphene sheet will remain flat on top of the corrugated substrate due to the unsatisfied bending energy or partially conform to the substrate due to the resistance of large interface friction. In order to reduce the effect of interface friction on the adhesive configuration, a new method, i.e. tilting the graphene sheet with a proper angle, is proposed. The tilting angle will significantly influence the final conformation of the adhesive interface. Some interesting types of behaviour are observed, such as rolling graphene, a double layer of graphene and fully adhesive contact, which is physically determined by the competition of thermal fluctuation and interfacial van der Waals interaction.

Chen, Hao; Yao, Yin; Chen, Shaohua

2013-05-01

430

ATHENA heat pipe transient model  

NASA Astrophysics Data System (ADS)

The ATHENA (Chow 1985) is a general purpose thermal hydraulic transient simulation code that was developed for the Magnetic Fusion Safety Project. The ATHENA two fluid model for two phase flow was modified to include the fluid physics unique to the heat pipe. This approach has resulted in a relatively sophisticated heat pipe transient model for a modest development effort. The model was used to simulate heat pipes for space power reactors, both as separate components and in integral simulation of coupled systems. The modifications that were made to the two fluid model to enable heat pipe simulation are described.

Ransom, Victor H.; Chow, Hueiming

431

Simulation and experimental research for piping damper with plunger-type accumulator  

NASA Astrophysics Data System (ADS)

It can be beneficial to reduce vibrations in shipboard piping, so the authors designed a new kind of piping damper with a plunger-type accumulator. Special requirements for the piping damper included low impact displacement, low speed, as well as an appropriate locking speed. Inside the damper, a plunger-type accumulator was installed and on the outside of the piston rod, a tube with exposed corrugations was added. Between the piston and the cylinder, a clearance seal was added. Using mathematical modeling, the effects of the dynamic performance of the damper’s impact displacement on vibrations were observed. Changes to the clearance between the piston and the cylinder, the stiffness of the spring in the accumulator, the throttle valve size, and locking speed resistance of the damper were respectively simulated and studied. Based on the results of the simulation, dampers with optimal parameters were developed and tested with different accumulator spring stiffnesses and different throttles. The simulation and experimental results showed that parameters such as seal clearance between piston and cylinder, accumulator spring stiffness and throttle parameters have significant effects on the damper’s impact displacement, low speed resistance and locking speed.

Luo, Xiao-Hui; Hu, Jun-Hua; Wang, Xiao-Bin; Niu, Zi-Hua

2010-09-01

432

Intermediate Temperature Fluids for Heat Pipes and Loop Heat Pipes  

Microsoft Academic Search

Potential working fluids for heat pipes and loop heat pipes include water, organic fluids, elements, and halides. The paper surveys life tests conducted with 30 different intermediate temperature working fluids, and over 60 different working fluid\\/envelope combinations. Life tests have been run with three elemental working fluids: sulfur, sulfur-iodine mixtures, and mercury. Other fluids offer benefits over these three liquids

William G. Anderson; John R. Hartenstine; David B. Sarraf; Calin Tarau

433

Longitudinal welded pipes with enhanced fatigue strength (Hifa ® pipe)  

Microsoft Academic Search

The transportation and storage of fluids in pipes can lead to cyclic loading due to fluctuating internal pressure which exceeds the normal pipeline operation range. In this special case, the design of the pipe is based on the fatigue strength rather than on the static strength. Normally a welded structure has a reduced fatigue resistance compared to a none- welded

M. Erdelen-Peppler; G. Knauf; Marewski Salzgitter; Mannesmann Forschung; O. Reepmeyer

434

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

435

Observation of organ-pipe acoustic excitations in supported thin films  

NASA Astrophysics Data System (ADS)

Brillouin light scattering from supported silicon oxynitride films reveal an extended series of acoustic excitations occurring at regular frequency intervals when the mode wave vector is perpendicular to the film surface. These periodic peaks are identified as distinct standing wave excitations that, similar to harmonics of an open-ended organ pipe, occur due to the boundary conditions imposed by the free surface and substrate-film interface. The surface ripple and volume elasto-optic scattering mechanisms contribute to the scattering cross sections and lead to dramatic interference effects at low frequencies where the surface corrugations play a dominant role. The transformation of these standing wave excitations to modes with finite in-plane wave vectors is also investigated. The results are discussed in the framework of a Green's-function formalism that reproduces the experimental features and illustrate the importance of the standing modes in evaluating the longitudinal elastic properties of the films.

Zhang, X.; Sooryakumar, R.; Every, A. G.; Manghnani, M. H.

2001-08-01

436

Cold Drawn ERW Pipes with Superior Formability,  

National Technical Information Service (NTIS)

Cold drawn ERW pipes have been applied in various fields. Cold drawn pipes show recrystallized microstructures when they are annealed for softening. Cold drawn ERW pipes sometimes show a difficulty in formability during cold working of expanding, swaging ...

T. Adaniya T. Takamura T. Meada F. Nishimura M. Morimoto

1988-01-01

437

Fire Endurance of Glassfibre Reinforcement Plastic Pipes.  

National Technical Information Service (NTIS)

Pipe systems on board ships are normally manufactured in steel. The application of glassfiber reinforced plastic (GRP) pipe systems in ship building offers, compared to steel pipes, several advantages such as light weight and a good corrosion resistance. ...

1984-01-01

438

49 CFR 195.112 - New pipe.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false New pipe. 195.112 Section 195...Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT...Design Requirements § 195.112 New pipe. Any new pipe installed in a pipeline...

2011-10-01

439

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

440

Exact derivation of the coupling coefficient in corrugated waveguides with arbitrary cross-section: application to optical fibers  

Microsoft Academic Search

Expressions for the coupling coefficient in corrugated waveguides with rectangular tooth shape are derived based on local mode expansion. The expressions are exact to first order in the tooth height (or index difference) for any waveguide cross-section. When applied to slab waveguides, the familiar expressions are obtained. Specializing to weakly guiding fibers, with step index profile, result in simple expressions

Amos Hardy

1995-01-01

441

Analysis of Doubly Corrugated Spoof Surface Plasmon Polariton (DC-SSPP) Structure With Sub-Wavelength Transmission at THz Frequencies  

Microsoft Academic Search

Devices utilizing spoof surface plasmon polariton (SSPP) effect in the terahertz (THz) domain has attracted increasing attention because such devices can be potentially used in fast signal processing and storages. In this paper, we present a comprehensive mathematical model of the doubly corrugated SSPP (DC-SSPP) structure derived from full-field analysis. Based on the proposed model, a complete characterization of the

Zhao Xu; Kyungjun Song; Pinaki Mazumder

2012-01-01

442

Experimental and numerical modelling comparison of thermal performance of expanded polystyrene and corrugated plastic packaging for fresh fish  

Microsoft Academic Search

Experiments were carried out to compare the thermal performance of wholesale fresh fish boxes made of corrugated plastic (CP) and expanded polystyrene (EPS). Free standing boxes containing whole, fresh fillets were exposed to dynamic thermal loads. The chilling effect of frozen ice packs was studied by including them in some of the boxes. The frozen ice packs proved efficient for

Björn Margeirsson; Radovan Gospavic; Halldór Pálsson; Sigurjón Arason; Viktor Popov

2011-01-01

443

Light reflection from the surface of a bilaterally corrugated waveguide and the features of light propagation in it  

Microsoft Academic Search

Anomalies in the spectral and angular dependences of the coefficient of light reflection from the surface of a bilaterally corrugated waveguide are investigated theoretically. Formulas for the radiative losses in this type of waveguide are presented and analyzed. For a certain ratio between the amplitudes and phases of the diffraction gratings, the waveguide radiation is outcoupled into only one of

I. A. Avrutskii; V. A. Sychugov

1987-01-01

444

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

2012-08-20

445

Superconducting pipes and levitating magnets  

Microsoft Academic Search

Motivated by a beautiful demonstration of the Faraday and the Lenz laws in which a small neodymium magnet falls slowly through a conducting nonferromagnetic tube, we consider the dynamics of a magnet falling coaxially through a superconducting pipe. Unlike the case of normal conducting pipes, in which the magnet quickly reaches the terminal velocity, inside a superconducting tube the magnet

Yan Levin; Felipe B. Rizzato

2006-01-01

446

Composite material heat pipe radiator  

Microsoft Academic Search

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

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

1996-01-01

447

Generator cooling using heat pipes  

Microsoft Academic Search

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

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

2006-01-01

448

Pipe crawler with stabilizing midsection  

SciTech Connect

This invention is comprised of a pipe crawler 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.

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

1993-09-20

449

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

450

Energy performance of plastic pipes  

Microsoft Academic Search

This paper studies the power needed to circulate heating water in building networks using different plastic pipes manufactured in Jordan. A suitable set up was designed and built for this purpose; the study included the effect of the rate of flow and the water temperature. On the basis of the results of pressure drop the pipes were divided as high

M Hammad

1999-01-01

451

Physical principles of heat pipes  

Microsoft Academic Search

Heat pipes are used whenever high rates of heat transfer or the control or conversion of heat flows are required. This book covers the physical principles of operation of heat pipes and choice of working fluid related to temperature range. The authors demonstrate how performance is limited by capillary pumping action in the wick together with impedance to liquid and

M. N. Ivanovskii; V. P. Sorokin; I. V. Yagodkin

1982-01-01

452

Closed loop pulsating heat pipes  

Microsoft Academic Search

Closed loop pulsating heat pipes (CLPHPs) are complex heat transfer devices having a strong thermo-hydrodynamic coupling governing the thermal performance. In this paper, a wide range of pulsating heat pipes is experimentally studied thereby providing vital information on the parameter dependency of their thermal performance. The influence characterization has been done for the variation of internal diameter, number of turns,

Piyanun Charoensawan; Sameer Khandekar; Manfred Groll; Pradit Terdtoon

2003-01-01

453

Building a copper pipe 'xylophone'  

Microsoft Academic Search

Music is central to the life of many students. This article describes using 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-like musical instrument or set of chimes from a 3 m section of copper pipe. The instrument produces a full major scale

David R. Lapp

2003-01-01

454

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

455

D0 Silicon Upgrade: Upgrade Piping Loads on Cleanroom Roof  

SciTech Connect

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

Sakla, Steve; /Fermilab

1995-08-28

456

A heat pipe quick disconnect  

NASA Astrophysics Data System (ADS)

This paper reports the proof of concept demonstration of a heat pipe quick disconnect being developed for the space constructible radiator system. The disconnect provides a maintainable coupling between the heat pipe evaporator, which is brazed to a mating heat exchanger, and the replaceable condenser section of a monogroove heat pipe radiator element. Test results, with pressurized nitrogen gas, confirm low leakage rates in both demated and mated configurations. Comparative thermal tests in a working 3 m (10 ft) test bed heat pipe using ammonia fluid revealed a 30 percent decrease in heat transport due to the additional minor pressure losses from the quick disconnect. The bulk of this loss is attributed to the transition section that joins the two adjacent heat pipe flow channels to the separated liquid and vapor passages within the disconnect coupling. It would be possible to decrease this overall loss in heat transport to under 10 percent with a redesigned transition section.

Alario, J. P.; Otterstedt, P. J.

1985-07-01

457

Promethus Hot Leg Piping Concept  

SciTech Connect

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.

AM Girbik; PA Dilorenzo

2006-01-24

458

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

459

Effects of Carbon Coating and Pore Corrugation on Capillary Condensation of Nitrogen in SBA-15 Mesoporous Silica.  

PubMed

To examine the origin of an ink-bottle-like structure in SBA-15 formed by carbon coating and the effects of pore corrugation on capillary condensation and evaporation of a vapor in the cylindrical pores, we measured the adsorption isotherms of nitrogen at 77 K on 10 kinds of SBA-15 samples before and after a carbon coating process by the exposure to acetylene at 1073 K, as well as desorption scanning curves and subloops on the untreated samples. These SBA-15 samples were synthesized under the different conditions of initial SiO2/P123 ratio and hydrothermal treatment. SBA-15 with relatively large microporosity tends to form easily constrictions inside the main channels by the carbon coating. This strongly suggests that the rough pore walls of SBA-15 may induce the incomplete wetting of carbon layers on the pore walls to form the constrictions inside the cylindrical pores. A comparison of two subloops implies that the pores of SBA-15 synthesized with a SiO2/P123 ratio of 75 consist of an assembly of connecting domains of different diameters; that is, the pores are highly corrugated. For SBA-15 synthesized with a SiO2/P123 ratio of 60, the amplitude of the pore corrugation is significantly decreased by the prolonged hydrothermal treatment at 373 K. On the other hand, for SBA-15 synthesized with a SiO2/P123 ratio of 45, the amplitude of the corrugation is negligibly small, although the cylindrical pores are interconnected through narrow necks with each other. It is found that the smaller the amplitude of the pore corrugation, the smaller the width of the hysteresis loop. PMID:23977846

Morishige, Kunimitsu

2013-09-11

460

The peeling behaviour of a graphene sheet on a nano-scale corrugated surface  

NASA Astrophysics Data System (ADS)

The peeling process and average peeling force of a graphene (GE) sheet on a corrugated surface are investigated using molecular dynamics simulation. It is found that the peeling behaviour varies with the substrate surface roughness and the peeling angle. Three kinds of typically peeling behaviours include (a) GE sheet directly passing the valley of the substrate roughness; (b) bouncing off from the substrate; and (c) continuously peeling off similarly to that on a flat substrate. As a result, the average peeling force is strongly dependent of the peeling behaviours. Furthermore, some interesting phenomena are caught, such as partial detaching and partial sliding of GE sheet in the valley of the substrate roughness, which are mainly due to the effects of pre-tension in GE sheet and the reduction of friction resistance. The results in this paper should be useful for the design of nano-film/substrate systems.

Chen, Hao; Chen, Shaohua

2013-10-01

461

Intrinsic broad-band white-light emission by a tuned, corrugated metal-organic framework.  

PubMed

Herein we report on the broad-band direct white-light originating from a single component emitter, namely a novel three-periodic metal-organic framework (MOF). This material features an unprecedented topology with (3,4)-connected nodes. The structure-function relationship in this system is driven by two complementary unique structural features: corrugation and interpenetration. Good correlation between simulated and experimental emission spectra has been attained, resulting in optimized color properties that approach requirements for solid-state lighting (SSL). Guided by the optimized calculated spectra, the tunability of the assembly was proven by the successful in-framework co-doping of Eu(3+). This resulted in significantly improved color properties, opening new paths for the rational design of alternative materials for SSL applications. PMID:22339608

Sava, Dorina F; Rohwer, Lauren E S; Rodriguez, Mark A; Nenoff, Tina M

2012-02-21

462

Convergent perturbative solution to the attractive corrugated hard wall model of atom--surface scattering  

SciTech Connect

The attractive corrugated wall model of atom--surface scattering is solved by an expansion method. The approach is similar to a Born expansion; however, projection operators must be introduced in order to obtain a convergent series near resonances. Diffraction intensities are calculated for He--LiF(001) and He--NaF(001) scattering. Good agreement with experimental intensities is obtained when the series is taken to convergence. In some cases (He--NaF) this requires calculation to as high as 12th order in the expansion parameter. At this order as many as 169 channels are included in the calculation. Preliminary estimates for the values for v/sub 01/ and v/sub 11/ for the He--NaF system have been found by comparison of theoretical and experimental intensities.

Wolfe-Brannon, K.; Weare, J.H.

1982-07-01

463

Sivashinsky equation for corrugated flames in the large-wrinkle limit.  

PubMed

Sivashinsky's [Acta Astron. 4, 1177 (1977)] nonlinear integrodifferential equation for the shape of corrugated one-dimensional flames is ultimately reducible to a 2N -body problem, involving the 2N complex poles of the flame slope. Thual, Frisch, and Hénon [J. Phys. (France) 46, 1485 (1985)] derived singular linear integral equations for the pole density in the limit of large steady wrinkles (N>1) , which they solved exactly for monocoalesced periodic fronts of highest amplitude of wrinkling and approximately otherwise. Here we solve those analytically for isolated crests, next for monocoalesced, then bicoalesced periodic flame patterns, whatever the (large) amplitudes involved. We compare the analytically predicted pole densities and flame shapes to numerical results deduced from the pole-decomposition approach. Good agreement is obtained, even for moderately large Ns . The results are extended to give hints as to the dynamics of supplementary poles. Open problems are evoked. PMID:18764058

Joulin, Guy; Denet, Bruno

2008-07-23

464

Implementation of the CMOS MEMS Condenser Microphone with Corrugated Metal Diaphragm and Silicon Back-Plate  

PubMed Central

This study reports a CMOS-MEMS condenser microphone implemented using the standard thin film stacking of 0.35 ?m UMC CMOS 3.3/5.0 V logic process, and followed by post-CMOS micromachining steps without introducing any special materials. The corrugated diaphragm for the microphone is designed and implemented using the metal layer to reduce the influence of thin film residual stresses. Moreover, a silicon substrate is employed to increase the stiffness of the back-plate. Measurements show the sensitivity of microphone is ?42 ± 3 dBV/Pa at 1 kHz (the reference sound-level is 94 dB) under 6 V pumping voltage, the frequency response is 100 Hz–10 kHz, and the S/N ratio >55 dB. It also has low power consumption of less than 200 ?A, and low distortion of less than 1% (referred to 100 dB).

Huang, Chien-Hsin; Lee, Chien-Hsing; Hsieh, Tsung-Min; Tsao, Li-Chi; Wu, Shaoyi; Liou, Jhyy-Cheng; Wang, Ming-Yi; Chen, Li-Che; Yip, Ming-Chuen; Fang, Weileun

2011-01-01

465

A new mechanism for negative refraction and focusing using selective diffraction from surface corrugation.  

PubMed

Refraction at a smooth interface is accompanied by momentum transfer normal to the interface. We show that corrugating an initially smooth, totally reflecting, non-metallic interface provides a momentum kick parallel to the surface, which can be used to refract light negatively or positively. This new mechanism of negative refraction is demonstrated by visible light and microwave experiments on grisms (grating-prisms). Single-beam all-angle-negative-refraction is achieved by incorporating a surface grating on a flat multilayered material. This negative refraction mechanism is used to create a new optical device, a grating lens. A planoconcave grating lens is demonstrated to focus plane microwaves to a point image. These results show that customized surface engineering can be used to achieve negative refraction even though the bulk material has positive refractive index. The surface periodicity provides a tunable parameter to control beam propagation leading to novel optical and microwave devices. PMID:19547258

Lu, W T; Huang, Y J; Vodo, P; Banyal, R K; Perry, C H; Sridhar, S

2007-07-23

466

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

467

Modification of old corrugated container pulp with laccase and laccase-mediator system.  

PubMed

Modification of the physical properties of old corrugated container (OCC) pulp with laccase or a laccase-mediator (ABTS, HBT, VA) system was investigated under select enzymatic concentrations and reaction times. The optimal conditions for laccase treatment shown to be using a laccase dose of 160U/g o.d. pulp, a treatment time of 20h at 25°C, pH 7 with a pulp consistency of 5%. Results showed that the Lac-HBT treated OCC pulp gave the best strength properties, improving tensile strength by 15.7%. The increase in the carboxyl group content of OCC laccase or Lac-HBT treated pulp led to the increase in the swelling ability and bonding between fibers. Microscope images showed the fiber surface became rougher and more collapsible after Lac-HBT treatment. FT-IR data showed that new carboxylic acid groups were formed during Lac-HBT treatment. PMID:22326330

Chen, Yangmei; Wan, Jinquan; Ma, Yongwen; Tang, Bing; Han, Wenjia; Ragauskas, Arthur J

2012-01-03

468

Acoustic technique for tracing plastic pipe  

SciTech Connect

Many gas distribution company operation and maintenance activities require precise knowledge of the location of buried plastic piping. Under sponsorship of the Southern California Gas Company, IGT successfully demonstrated an acoustic plastic pipe location technique and is developing that technique into a practical field instrument. An acoustic signal is injected into the plastic pipe such that it propagates through the pipe. As the acoustic wave travels along the pipe, some of the sound radiates from the pipe to the surface of the ground. An array of sensors on the surface of the ground perpendicular to the pipe detects the acoustic signal, thereby locating the pipe. Two different acoustic measurements are used. The first measurement locates the pipe to within + 1.2 m (+ 4.0 ft). The second technique then determines the location of the pipe to within + 15 cm (+ 6 in.) and gives an estimate of pipe depth.

Huebler, J.E.; Campbell, B.K. [Institute of Gas Technology, Chicago, IL (United States); Ching, G.K. [Southern California Gas Co., Los Angeles, CA (United States)

1992-12-31

469

Acoustic technique for tracing plastic pipe  

SciTech Connect

Many gas distribution company operation and maintenance activities require precise knowledge of the location of buried plastic piping. Under sponsorship of the Southern California Gas Company, IGT successfully demonstrated an acoustic plastic pipe location technique and is developing that technique into a practical field instrument. An acoustic signal is injected into the plastic pipe such that it propagates through the pipe. As the acoustic wave travels along the pipe, some of the sound radiates from the pipe to the surface of the ground. An array of sensors on the surface of the ground perpendicular to the pipe detects the acoustic signal, thereby locating the pipe. Two different acoustic measurements are used. The first measurement locates the pipe to within + 1.2 m (+ 4.0 ft). The second technique then determines the location of the pipe to within + 15 cm (+ 6 in.) and gives an estimate of pipe depth.

Huebler, J.E.; Campbell, B.K. (Institute of Gas Technology, Chicago, IL (United States)); Ching, G.K. (Southern California Gas Co., Los Angeles, CA (United States))

1992-01-01

470

Mixing in Helical Pipes  

NASA Astrophysics Data System (ADS)

We consider advection and diffusion of a passive scalar in a helical pipe. By assuming that the curvature and torsion are small (equivalent to small Dean number) and the Reynolds number is moderate, we can use a closed form approximation, due to Dean (1927) and Germano (1982), for the induced recirculation. We investigate the problem numerically using a split-step particle method for a variety of localized initial conditions. The problem is governed by two parameters: a nondimensional diffusion constant D (typically small), and the scaled ratio of torsion to curvature ?. At small times, the longitudinal width of the particle distribution, ?, is governed by diffusive effects (? ? ?Dt). At large times, Taylor diffusion dominates (? ? ?t/D). However, at intermediate times, a ballistic region exists where the width spreads linearly, as postulated by Mezic & Wiggins (1994). We also discuss how these various behaviors scale with the parameters D and ?.

Gratton, Michael B.; Bernoff, Andrew J.

2001-11-01

471

Updating pipe insulation  

SciTech Connect

Every plant engineer knows that proper insulation saves energy. The right insulation also increases plant yields and capacity without capital expansion. Field experience has shown that proper insulation, a combination of the right material, thickness, and jacketing helps maintain optimum temperatures throughout a process. The result is processes that safely run hotter and faster, and produce more acceptable product. In hydrocarbon processing, for example, insulating fuel, lubricant, and petrochemical lines helps ensure more premium-grade product. In power generation, better insulation means more saleable electricity per ton of fuel. In chemical processing, properly insulating process heat lines for reactor vessels and turbines means consistent product and less scrap. The same holds true for pulp and paper processing (especially at the pulping end), textile manufacturing, and food processing. This paper briefly explains a 5-step program to help a plant engineer determine the plant's pipe insulation requirements.

Rickards, D. (CertainTeed Corp., Valley Forge, PA (United States))

1993-03-04

472

Pipe initiation anchor  

SciTech Connect

In a pipe initiation anchor for forming a fixed anchor point for use in laying underwater pipelines, this patent described the combination of: a frame; a ground engaging member; means for attaching the frame to the ground engaging member; and socket means carried in the frame defining a socket for receiving and retaining the end portion of the pipeline within the socket. The socket means include first and second generally horizontal bars, with the first bar mounted in the frame and with the second bar mounted on a pivoting member in the frame and spaced from the first bar, and a counter-balance weight carried on the pivoting member urging the second bar toward the first bar.

Morris, G.A.

1987-10-27

473

Superconducting pipes and levitating magnets.  

PubMed

Motivated by a beautiful demonstration of the Faraday and the Lenz laws in which a small neodymium magnet falls slowly through a conducting nonferromagnetic tube, we consider the dynamics of a magnet falling coaxially through a superconducting pipe. Unlike the case of normal conducting pipes, in which the magnet quickly reaches the terminal velocity, inside a superconducting tube the magnet falls freely. On the other hand, to enter the pipe the magnet must overcome a large electromagnetic energy barrier. For sufficiently strong magnets, the barrier is so large that the magnet will not be able to penetrate it and will be levitated over the mouth of the pipe. We calculate the work that must done to force the magnet to enter a superconducting tube. The calculations show that superconducting pipes are very efficient at screening magnetic fields. For example, the magnetic field of a dipole at the center of a short pipe of radius a and length L approximately > a decays, in the axial direction, with a characteristic length xi approximately 0.26a. The efficient screening of the magnetic field might be useful for shielding highly sensitive superconducting quantum interference devices. Finally, the motion of the magnet through a superconducting pipe is compared and contrasted to the flow of ions through a trans-membrane channel. PMID:17280160

Levin, Yan; Rizzato, Felipe B

2006-12-12

474

Equations shorten pipe collapse calculations  

SciTech Connect

The API suggests collapse pressure equations for long, perfectly round, steel oil field casing, tubing, drill pipe, and line pipe. Operating and service company engineers can substitute two pipe collapse pressure equations for the 12 API equations now in general use. The shorthand results are almost the same as those from the API equations. The shorthand method has the additional advantage of allowing units from any measurement system. The API equations restrict calculations to US units only. The equation box lists the API (Equations 1--12) and the shorthand (Equations 13--14) equations. The API equations are based on work started shortly after the turn of the century.

Avakov, V.A. [Halliburton Energy Services, Duncan, OK (United States)

1995-04-10

475

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

476

Thermal performance of insulated pipe systems  

Microsoft Academic Search

The thermal performance of insulated pipe systems was measured as a function of insulation and pipe system parameters. Insulation parameters included insulation material, thickness, and air gaps at seams and joints. Pipe system parameters were pipe size, hangers, supports, and operating temperature. Over 150 thermal performance tests were recorded and analyzed over a two-year period. Test results show a 15

1981-01-01

477

Thermal performance of insulated pipe systems  

Microsoft Academic Search

The thermal performance of insulated pipe systems was measured as a function of insulation and pipe system parameters. Insulation parameters included insulation material, thickness, and air gaps at seams and joints. Pipe system parameters were pipe size, hangers, supports, and operating temperature. Over 150 thermal performance tests were recorded and analyzed over a two-year period. Test results show a 15%

J. M. Jr

1983-01-01

478

Pipe insulating system and apparatus therefor  

Microsoft Academic Search

A system is described for insulating pipe with a foamed material, such as polyurethane, which includes an apparatus for forming a mold about the pipe into which the foam may be injected, apparatus for propelling the pipe through the mold, and support rollers for supporting the pipe before the foam sets without damaging or permanently deforming the foamed insulation. The

Baughmann

1975-01-01

479

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

480

Laboratory Load Tests on Buried Flexible Pipe.  

National Technical Information Service (NTIS)

As part of a study on soil factors affecting the behavior of buried pipe, research is being conducted on the soil-structure interaction of buried flexible pipe; earlier tests dealt with rigid pipe. The main items of investigation on flexible pipe are soil...

A. K. Howard

1968-01-01

481

Heat pipes and their technical applications  

Microsoft Academic Search

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

L. L. Vasilev

1976-01-01

482

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

483

Recent advances in pipe support design  

SciTech Connect

This conference proceedings contains 10 papers. The topics covered include: analysis of base plates; design of pipe restraint end attachments; analysis of rigid struts; computer aided design of pipe supports; loading on connection angle clips; column to support nuclear piping systems; velocity sensitive hydraulic snubbers; load characteristics of pipe clamps. One paper is abstracted separately.

van Stijgeren, E.

1982-01-01

484

Flexible PMMA pipe for terahertz propagation  

NASA Astrophysics Data System (ADS)

We present an experimental study on a flexible terahertz (THz) pipe PMMA waveguide. The attenuation loss of this pipe at 3.1THz was 9.65dB/m. Further more, bending loss of the pipe waveguides was investigated. The experimental result shows good transmission properties of the pipe.

Liu, Jing; Xiao, Mingfei; Shen, Jingling; Zhang, Wei

2012-12-01

485

49 CFR 192.279 - Copper pipe.  

Code of Federal Regulations, 2011 CFR

...Transportation 3 2011-10-01 2011-10-01 false Copper pipe. 192.279 Section 192.279 Transportation...of Materials Other Than by Welding § 192.279 Copper pipe. Copper pipe may not be threaded except that copper pipe...

2011-10-01

486

49 CFR 192.279 - Copper pipe.  

Code of Federal Regulations, 2010 CFR

...Transportation 3 2009-10-01 2009-10-01 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 pipe...

2009-10-01

487

49 CFR 192.279 - Copper pipe.  

Code of Federal Regulations, 2012 CFR

...Transportation 3 2012-10-01 2012-10-01 false Copper pipe. 192.279 Section 192.279 Transportation...of Materials Other Than by Welding § 192.279 Copper pipe. Copper pipe may not be threaded except that copper pipe...

2012-10-01

488

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 pipe...

2010-10-01

489

Seismic Proving Test of Eroded Piping (Status of Eroded Piping Component and System Test)  

Microsoft Academic Search

In FY 2000, a 3-year testing program of eroded piping was initiated with the following objectives: 1) to ascertain the seismic safety margins for eroded piping designed under the current seismic design code, 2) to clarify the elasto-plastic response and ultimate strength of eroded nuclear piping. A series of tests on eroded piping components and eroded piping systems was planned.

Y. Namita; K. Suzuki; H. Abe; I. Ichihashi; M. Shiratori; K. Iwata; A. Nebu

490

Nitrogen heat pipe for cryocooler thermal shunt  

SciTech Connect

A nitrogen heat pipe was designed, built and tested for the purpose of providing a thermal shunt between the two stages of a Gifford-McMahan (GM) cryocooler during cooldown. The nitrogen heat pipe has an operating temperature range between 63 and 123 K. While the heat pipe is in the temperature range during the system cooldown, it acts as a thermal shunt between the first and second stage of the cryocooler. The heat pipe increases the heat transfer to the first stage of the cryocooler, thereby reducing the cooldown time of the system. When the heat pipe temperature drops below the triple point, the nitrogen working fluid freezes, effectively stopping the heat pipe operation. A small heat leak between cryocooler stages remains because of axial conduction along the heat pipe wall. As long as the heat pipe remains below 63 K, the heat pipe remains inactive. Heat pipe performance limits were measured and the optimum fluid charge was determined.

Prenger, F.C.; Hill, D.D.; Daney, D.E.; Daugherty, M.A. [Los Alamos National Lab., NM (United States); Green, G.F.; Roth, E.W. [Naval Surface Warfare Center, Annapolis, MD (United States)

1995-09-01

491

B Plant process piping replacement feasibility study  

SciTech Connect

Reports on the feasibility of replacing existing embedded process piping with new more corrosion resistant piping between cells and between cells and a hot pipe trench of a Hanford Site style canyon facility. Provides concepts for replacement piping installation, and use of robotics to replace the use of the canyon crane as the primary means of performing/supporting facility modifications (eg, cell lining, pipe replacement, equipment reinstallation) and operational maintenenace.

Howden, G.F.

1996-02-07

492

Protection cover for pipe bends  

US Patent & Trademark Office Database

A protection cover for pipe bends produced from a plastic material by deep drawing into a shape which is similar to the shape which could be obtained if an integral and complete cover installed on a pipe bend had been cut along the interior generatrics line of the pipe bend and spread apart and opened up. The shape of the present protection cover is further modified by having a cup-shaped part generally elongated and rounded in transverse cross-section and having integral therewith tail sections located at each short side of the cup-shaped part. Each of the tail sections have a concave bend therein. The overall shape of the protection cover is such that when the cover is applied over an insulated pipe bend, the cover will have on its interior side a curvature radius that is essentially greater than the curvature radius of its exterior side, and the two curvature radii will have mutually different centers.

1976-06-01

493

Idea Bank: Pipe Cleaner DNA  

NSDL National Science Digital Library

The pipe cleaner DNA model uses simple materials, but offers limitless opportunities for realistic manipulation, including DNA replication, mutation, and protein synthesis. The activity is also appropriate for students at many levels.

Rosenkrantz, Kurt

2004-05-01

494

Heat Pipe Applications Workshop Report.  

National Technical Information Service (NTIS)

The proceedings of the Heat Pipe Applications Workshop, held at the Los Alamos Scientific Laboratory October 20-21, 1977, are reported. This workshop, which brought together representatives of the Department of Energy and of a dozen industrial organizatio...

W. A. Ranken

1978-01-01

495

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

496

LARGE-BORE PIPE DECONTAMINATION  

SciTech Connect

The decontamination and characterization of large-bore pipe is difficult because of the various geometries and diameters of pipe and its different material types. A robust decontamination system must be capable of adapting to different pipe diameters (project scope is 6 inches to 24 inches), cleaning surfaces with various surface conditions and material types (i.e., painted, rusted, carbon steel, or stainless steel), and be cost-effective to operate and maintain. The characterization system must be capable of handling the different pipe parameters and detecting contamination on the inside and outside surfaces. It must also operate in a cost-effective manner. Current technology options do not provide a robust system to meet these objectives. The purpose of this project is to verify the need for this technology through determining quantities of pipe available for decontamination (completed FY97), perform a technology screening process to select technologies for decontamination (completed FY97) and characterization (completed FY98), perform treatability studies to collect required performance data (completed FY97), and design and fabricate a prototype system to decontaminate and characterize the internal and external surfaces of large-bore pipe. A field mobile system capable of performing decontamination and characterization operations will be the main deliverable for this project. A summary of activities completed during FY97 is provided to understand the project development and implementation process.

M.A. Ebadian

1999-01-01

497

Composite material heat pipe radiator  

SciTech Connect

Organic matrix composite material is recognized for its significant strength to weight ratio when compared to metal and consequently was investigated for reducing the mass of heat pipes for future space missions. The particular heat pipe that was constructed and tested was made from an organic matrix composite material applied to a linear of titanium tubing spun to foil thickness (0.076 mm). The thin liner transitioned to heavier-walled ends which allowed the tubing to be sealed using conventional welding. More specifically, the heat pipe was 1.14 m long, 24 mm in diameter and had a mass of 0.165 kg. Water was the working fluid. The heat pipe was tested in a Thermacore thermal vacuum chamber under hot and cold wall operating conditions. The heat load dissipated ranged from 10 to 60 watts. Heat pipe operating temperatures varied from 278 K to 403 K. After testing, the heat pipe was delivered to NASA JSC where future thermal vacuum chamber tests are planned. {copyright} {ital 1996 American Institute of Physics.}

Gernert, N.J.; Sarraf, D.B. [Thermacore, Inc., 780 Eden Road, Lancaster, Pennsylvania 17601 (United States); Guenther, R.J. [Battelle, Pacific Northwest Laboratories, Richland, Washington 99352 (United States); Hurlbert/, K.M. [NASA Johnson Space Center, 2101 NASA Road, 1 Houston, Texas 77058-3696 (United States); EC3

1996-03-01

498

Pipe weld crown removal device  

DOEpatents

This invention is comprised of a device that provides for grinding down the crown of a pipe weld joining aligned pipe sections so that the weld is substantially flush with the pipe sections joined by the weld. The device includes a cage assembly comprising a pair of spaced cage rings adapted to be mounted for rotation on the respective pipe sections on opposite sides of the weld, a plurality of grinding wheels, supported by the cage assembly for grinding down the crown of the weld, and a plurality of support shafts, each extending longitudinally along the joined pipe sections, parallel thereto, for individually mounting respective grinding wheels. Each end of the support shafts is mounted for rotation in a bearing assembly housed within a radially directed opening in a corresponding one of the cage rings so as to provide radial movement of the associated shaft, and thus of the associated grinding wheel, towards and away from the weld. A first drive sprocket provides rotation of the cage assembly around the pipe sections while a second drive unit, driven by a common motor, provides rotation of the grinding wheels.

Sword, C.K.; Sette, P.J.

1991-12-31

499

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

500

The dynamic response of end-clamped sandwich beams with a Y-frame or corrugated core  

Microsoft Academic Search

The dynamic response of end-clamped monolithic beams and sandwich beams has been measured by loading the beams at mid-span using metal foam projectiles. The AISI 304 stainless-steel sandwich beams comprise two identical face sheets and either prismatic Y-frame or corrugated cores. The resistance to shock loading is quantified by the permanent transverse deflection at mid-span of the beams as a

V. Rubino; V. S. Deshpande; N. A. Fleck

2008-01-01