Science.gov

Sample records for rivets

  1. Rivet Graphene.

    PubMed

    Li, Xinlu; Sha, Junwei; Lee, Seoung-Ki; Li, Yilun; Ji, Yongsung; Zhao, Yujie; Tour, James M

    2016-08-23

    Large-area graphene has emerged as a promising material for use in flexible and transparent electronics due to its flexibility and optical and electronic properties. The anchoring of transition metal nanoparticles on large-area single-layer graphene is still a challenge. Here, we report an in situ preparation of carbon nano-onion-encapsulated Fe nanoparticles on rebar graphene, which we term rivet graphene. The hybrid film, which allows for polymer-free transfer and is strong enough to float on water with no added supports, exhibits high optical transparency, excellent electric conductivity, and good hole/electron mobility under certain tensile/compressive strains. The results of contact resistance and transfer length indicate that the current in the rivet graphene transistor does not just flow at the contact edge. Carbon nano-onions encapsulating Fe nanoparticles on the surface enhance the injection of charge between rivet graphene and the metal electrode. The anchoring of Fe nanoparticles encapsulated by carbon nano-onions on rebar graphene will provide additional avenues for applications of nanocarbon-based films in transparent and flexible electronics. PMID:27351673

  2. Riveting in metal airplane construction. Part II : riveting methods and equipment (concluded)

    NASA Technical Reports Server (NTRS)

    Pleines, Wilhelm

    1930-01-01

    This report includes descriptive material on rivet inspection, types of rivets and sizes. Tabular data on shearing strength of rivets at failure, ultimate shear of various rivets, tensile tests of rivet plate, and tensile strength values of riveted joints.

  3. Rivet user manual

    NASA Astrophysics Data System (ADS)

    Buckley, Andy; Butterworth, Jonathan; Grellscheid, David; Hoeth, Hendrik; Lönnblad, Leif; Monk, James; Schulz, Holger; Siegert, Frank

    2013-12-01

    This is the manual and user guide for the Rivet system for the validation and tuning of Monte Carlo event generators. As well as the core Rivet library, this manual describes the usage of the rivet program and the AGILe generator interface library. The depth and level of description is chosen for users of the system, starting with the basics of using validation code written by others, and then covering sufficient details to write new Rivet analyses and calculational components. Catalogue identifier: AEPS_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEPS_v1_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 571126 No. of bytes in distributed program, including test data, etc.: 4717522 Distribution format: tar.gz Programming language: C++, Python. Computer: PC running Linux, Mac. Operating system: Linux, Mac OS. RAM: 20 MB Classification: 11.9, 11.2. External routines: HepMC (https://savannah.cern.ch/projects/hepmc/), GSL (http://www.gnu.org/software/gsl/manual/gsl-ref.html), FastJet (http://fastjet.fr/), Python (http://www.python.org/), Swig (http://www.swig.org/), Boost (http://www.boostsoftware.com/), YAML (http://www.yaml.org/spec/1.2/spec.html) Nature of problem: Experimental measurements from high-energy particle colliders should be defined and stored in a general framework such that it is simple to compare theory predictions to them. Rivet is such a framework, and contains at the same time a large collection of existing measurements. Solution method: Rivet is based on HepMC events, a standardised output format provided by many theory simulation tools. Events are processed by Rivet to generate histograms for the requested list of analyses, incorporating all experimental phase space cuts and histogram definitions. Restrictions: Cannot calculate

  4. Riveting in metal airplane construction. Part IV : strength of riveted joints in duralumin (concluded)

    NASA Technical Reports Server (NTRS)

    Pleines, Wilhelm

    1930-01-01

    Tests were made to determine the crushing strength of a riveted joint, in order to define the difference in crushing stregth between a strictly bolted joint and a riveted joint. The object was to tabulate the crushing strength by failure on various plate thicknesses for a one-rivet double-shear riveted joint.

  5. Caring for Rosie the Riveter's Children

    ERIC Educational Resources Information Center

    MacKenzie, Bill

    2011-01-01

    During the Second World War, women in the United States who worked in the war industries in such jobs as welders, riveters, heavy machinery operators, and parachute riggers were heralded in the media as "Rosie the Riveter." From 1943 to 1945 a fortunate few of these workplace pioneers participated in a memorable experiment in child care at Kaiser…

  6. 49 CFR 230.28 - Higher shearing strength of rivets.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Appurtenances Strength of Materials § 230.28 Higher shearing strength of rivets. A higher shearing strength may be used for rivets when it can be shown through testing that the rivet material used is of such... 49 Transportation 4 2014-10-01 2014-10-01 false Higher shearing strength of rivets. 230.28...

  7. 49 CFR 230.28 - Higher shearing strength of rivets.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Appurtenances Strength of Materials § 230.28 Higher shearing strength of rivets. A higher shearing strength may be used for rivets when it can be shown through testing that the rivet material used is of such... 49 Transportation 4 2013-10-01 2013-10-01 false Higher shearing strength of rivets. 230.28...

  8. 49 CFR 230.28 - Higher shearing strength of rivets.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Appurtenances Strength of Materials § 230.28 Higher shearing strength of rivets. A higher shearing strength may be used for rivets when it can be shown through testing that the rivet material used is of such... 49 Transportation 4 2011-10-01 2011-10-01 false Higher shearing strength of rivets. 230.28...

  9. 49 CFR 230.28 - Higher shearing strength of rivets.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Appurtenances Strength of Materials § 230.28 Higher shearing strength of rivets. A higher shearing strength may be used for rivets when it can be shown through testing that the rivet material used is of such... 49 Transportation 4 2012-10-01 2012-10-01 false Higher shearing strength of rivets. 230.28...

  10. 49 CFR 230.28 - Higher shearing strength of rivets.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Appurtenances Strength of Materials § 230.28 Higher shearing strength of rivets. A higher shearing strength may be used for rivets when it can be shown through testing that the rivet material used is of such... 49 Transportation 4 2010-10-01 2010-10-01 false Higher shearing strength of rivets. 230.28...

  11. Riveting in metal airplane construction. Part III : strength of riveted joints in duralumin (continued)

    NASA Technical Reports Server (NTRS)

    Pleines, Wilhelm

    1930-01-01

    This report includes strength of riveted joints in duralumin, descriptions of test procedure and results of tests. Tabulated data includes: curshing strength by failure for various conditions, shearing strength of hole edge zone in direction of tearing, tearing strengths of plates weakened by rivet holes, and enlargement of holes at beginning of break.

  12. 46 CFR 59.10-15 - Rivets and staybolts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... VESSELS AND APPURTENANCES Welding Repairs to Boilers and Pressure Vessels in -Service § 59.10-15 Rivets and staybolts. (a) It is not permitted to reinforce or build up by welding the heads of rivets or staybolts that have deteriorated. Such rivets or staybolts shall be replaced. The seal welding of...

  13. 46 CFR 59.10-15 - Rivets and staybolts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... VESSELS AND APPURTENANCES Welding Repairs to Boilers and Pressure Vessels in -Service § 59.10-15 Rivets and staybolts. (a) It is not permitted to reinforce or build up by welding the heads of rivets or staybolts that have deteriorated. Such rivets or staybolts shall be replaced. The seal welding of...

  14. 46 CFR 59.10-15 - Rivets and staybolts.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... VESSELS AND APPURTENANCES Welding Repairs to Boilers and Pressure Vessels in -Service § 59.10-15 Rivets and staybolts. (a) It is not permitted to reinforce or build up by welding the heads of rivets or staybolts that have deteriorated. Such rivets or staybolts shall be replaced. The seal welding of...

  15. 46 CFR 59.10-15 - Rivets and staybolts.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... VESSELS AND APPURTENANCES Welding Repairs to Boilers and Pressure Vessels in -Service § 59.10-15 Rivets and staybolts. (a) It is not permitted to reinforce or build up by welding the heads of rivets or staybolts that have deteriorated. Such rivets or staybolts shall be replaced. The seal welding of...

  16. 46 CFR 59.10-15 - Rivets and staybolts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... VESSELS AND APPURTENANCES Welding Repairs to Boilers and Pressure Vessels in -Service § 59.10-15 Rivets and staybolts. (a) It is not permitted to reinforce or build up by welding the heads of rivets or staybolts that have deteriorated. Such rivets or staybolts shall be replaced. The seal welding of...

  17. The Effect of Surface Irregularities on Wing Drag. I. Rivets and Spot Welds. 1; Rivets and Spot Welds

    NASA Technical Reports Server (NTRS)

    Hood, Manley J.

    1938-01-01

    Tests have been conducted in the NACA 8-foot high-speed wind tunnel to determine the effect of exposed rivet heads and spot welds on wing drag. Most of the tests were made with an airfoil of 5-foot chord. The air speed was varied from 80 to 500 miles per hour and the lift coefficient from 0 to 0.30. The increases in the drag of the 5-foot airfoil varied from 6%, due to countersunk rivets, to 27%, due to 3/32-inch brazier-head rivets, with the rivets in a representative arrangement. The drag increases caused by protruding rivet heads were roughly proportional to the height of the heads. With the front row of rivets well forward, changes in spanwise pitch had negligible effects on drag unless the pitch was more than 2.5% of the chord. Data are presented for evaluating the drag reduction attained by removing rivets from the forward part of the wing surface; for example, it is shown that over 70% of the rivet drag is caused by the rivets on the forward 30% of the airfoil in a typical case.

  18. Revolving Eddy-Current Probe Detects Cracks Near Rivets

    NASA Technical Reports Server (NTRS)

    Namkung, Min; Wincheski, Buzz; Fulton, James P.; Nath, Shridhar; Simpson, John

    1995-01-01

    Scanning eddy-current probe in circular pattern increases sensitivity with which probe indicates fatigue cracks and other defects in metal surfaces in vicinity of rivets. Technique devised to facilitate inspection of riveted joints in aircraft. Eddy-current probe in question described in "Electro-magnetic Flaw Detector Is Easier To Use" (LAR-15046).

  19. 22. SHIPYARD NO. 2, ROSIE THE RIVETER MEMORIAL (SEE ALSO ...

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

    22. SHIPYARD NO. 2, ROSIE THE RIVETER MEMORIAL (SEE ALSO HAER No. CA-326-D), FORD ASSEMBLY PLANT (SEE ALSO HAER No. CA-326-H), AND RICHMOND SHIPYARD NO. 3, SW. - Rosie the Riveter National Historical Park, 1401 Marina Way South, Richmond, Contra Costa County, CA

  20. 49 CFR 230.27 - Maximum shearing strength of rivets.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Strength of Materials § 230.27 Maximum shearing strength of rivets. The maximum shearing strength... 49 Transportation 4 2010-10-01 2010-10-01 false Maximum shearing strength of rivets....

  1. 49 CFR 230.27 - Maximum shearing strength of rivets.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Strength of Materials § 230.27 Maximum shearing strength of rivets. The maximum shearing strength... 49 Transportation 4 2011-10-01 2011-10-01 false Maximum shearing strength of rivets....

  2. 49 CFR 230.27 - Maximum shearing strength of rivets.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Strength of Materials § 230.27 Maximum shearing strength of rivets. The maximum shearing strength... 49 Transportation 4 2012-10-01 2012-10-01 false Maximum shearing strength of rivets....

  3. 49 CFR 230.27 - Maximum shearing strength of rivets.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Strength of Materials § 230.27 Maximum shearing strength of rivets. The maximum shearing strength... 49 Transportation 4 2013-10-01 2013-10-01 false Maximum shearing strength of rivets....

  4. 49 CFR 230.27 - Maximum shearing strength of rivets.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Strength of Materials § 230.27 Maximum shearing strength of rivets. The maximum shearing strength... 49 Transportation 4 2014-10-01 2014-10-01 false Maximum shearing strength of rivets....

  5. 46 CFR 109.573 - Riveting, welding, and burning operations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Riveting, welding, and burning operations. 109.573... DRILLING UNITS OPERATIONS Miscellaneous § 109.573 Riveting, welding, and burning operations. Except as..., welding, or burning— (1) In a fuel tank; (2) On the boundary of a fuel tank; (3) On pipelines,...

  6. 46 CFR 109.573 - Riveting, welding, and burning operations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Riveting, welding, and burning operations. 109.573... DRILLING UNITS OPERATIONS Miscellaneous § 109.573 Riveting, welding, and burning operations. Except as..., welding, or burning— (1) In a fuel tank; (2) On the boundary of a fuel tank; (3) On pipelines,...

  7. 46 CFR 109.573 - Riveting, welding, and burning operations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Riveting, welding, and burning operations. 109.573... DRILLING UNITS OPERATIONS Miscellaneous § 109.573 Riveting, welding, and burning operations. Except as..., welding, or burning— (1) In a fuel tank; (2) On the boundary of a fuel tank; (3) On pipelines,...

  8. 46 CFR 109.573 - Riveting, welding, and burning operations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Riveting, welding, and burning operations. 109.573... DRILLING UNITS OPERATIONS Miscellaneous § 109.573 Riveting, welding, and burning operations. Except as..., welding, or burning— (1) In a fuel tank; (2) On the boundary of a fuel tank; (3) On pipelines,...

  9. 46 CFR 109.573 - Riveting, welding, and burning operations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Riveting, welding, and burning operations. 109.573... DRILLING UNITS OPERATIONS Miscellaneous § 109.573 Riveting, welding, and burning operations. Except as..., welding, or burning— (1) In a fuel tank; (2) On the boundary of a fuel tank; (3) On pipelines,...

  10. Tensile Tests of NACA and Conventional Machine-countersunk Flush Rivets

    NASA Technical Reports Server (NTRS)

    Bartone, Leonard M.; Mandel, Merven W.

    1944-01-01

    An investigation was conducted to determine and compare the tensile strength of NACA and conventional machine-countersunk flush rivets of several rivet-head angles and varying countersunk depth. The results of the investigation are presented in the form of curves that show the variation of the tensile strength of the rivet with the ratio of the sheet thickness to the rivet diameter. For the same rivet-head angle and for a given angle of c/d, the NACA rivets developed higher tensile strength than the conventional rivets.

  11. Residual Strength Analyses of Riveted Lap-Splice Joints

    NASA Technical Reports Server (NTRS)

    Seshadri, B. R.; Newman, J. C., Jr.

    2000-01-01

    The objective of this paper was to analyze the crack-linkup behavior in riveted-stiffened lap-splice joint panels with small multiple-site damage (MSD) cracks at several adjacent rivet holes. Analyses are based on the STAGS (STructural Analysis of General Shells) code with the critical crack-tip-opening angle (CTOA) fracture criterion. To account for high constraint around a crack front, the "plane strain core" option in STAGS was used. The importance of modeling rivet flexibility with fastener elements that accurately model load transfer across the joint is discussed. Fastener holes are not modeled but rivet connectivity is accounted for by attaching rivets to the sheet on one side of the cracks that simulated both the rivet diameter and MSD cracks. Residual strength analyses made on 2024-T3 alloy (1.6-mm thick) riveted-lap-splice joints with a lead crack and various size MSD cracks were compared with test data from Boeing Airplane Company. Analyses were conducted for both restrained and unrestrained buckling conditions. Comparison of results from these analyses and results from lap-splice-joint test panels, which were partially restrained against buckling indicate that the test results were bounded by the failure loads predicted by the analyses with restrained and unrestrained conditions.

  12. 12. VIEW OF FLOOR BEAMS, GUSSET PLATES, RIVET CONNECTIONS, LACED ...

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

    12. VIEW OF FLOOR BEAMS, GUSSET PLATES, RIVET CONNECTIONS, LACED VERTICALS AND LATTICE RAILING, LOOKING NORTHWEST - Attica Bridge, Spanning Deer Creek on County Road 500 East, Young America, Cass County, IN

  13. 8. SOUTH VIEW, RIVETED CONNECTION POINT OF TOP CHORD, DIAGONAL ...

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

    8. SOUTH VIEW, RIVETED CONNECTION POINT OF TOP CHORD, DIAGONAL TENSION MEMBER, INCLINED END POST AND VERTICAL MEMBER - Jordan Narrows Bridge, Crossing Jordan River at 9600 North, Lehi, Utah County, UT

  14. 12. Detail view (looking east) of riveted cconnection of top ...

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

    12. Detail view (looking east) of riveted cconnection of top chord and vertical members at the second panel point north from south abutment of Moody Bridge. - Moody Bridge, Spanning South Fork Eel River, Garberville, Humboldt County, CA

  15. 23. NORTHEAST TO CIRCA 1875 POWER SHEAR, PUNCH, AND RIVETING ...

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

    23. NORTHEAST TO CIRCA 1875 POWER SHEAR, PUNCH, AND RIVETING MACHINE SET UP TO DEMONSTRATE USE IN RIVETING COMPONENTS OF WHEEL ARMS FOR ELI WINDMILLS. HISTORIC DEBRIS FROM PUNCHING WORK IS VISIBLE BENEATH THE MACHINE IN THE OPERATOR'S PIT.' ON THE LEFT IS A U-SHAPED LOVEJOY FIELD PUNCH FOR USE IN INSTALLING STEEL WINDMILL/TOWER COMPONENTS. - Kregel Windmill Company Factory, 1416 Central Avenue, Nebraska City, Otoe County, NE

  16. Laboratory and workplace assessments of rivet bucking bar vibration emissions.

    PubMed

    McDowell, Thomas W; Warren, Christopher; Xu, Xueyan S; Welcome, Daniel E; Dong, Ren G

    2015-04-01

    Sheet metal workers operating rivet bucking bars are at risk of developing hand and wrist musculoskeletal disorders associated with exposures to hand-transmitted vibrations and forceful exertions required to operate these hand tools. New bucking bar technologies have been introduced in efforts to reduce workplace vibration exposures to these workers. However, the efficacy of these new bucking bar designs has not been well documented. While there are standardized laboratory-based methodologies for assessing the vibration emissions of many types of powered hand tools, no such standard exists for rivet bucking bars. Therefore, this study included the development of a laboratory-based method for assessing bucking bar vibrations which utilizes a simulated riveting task. With this method, this study evaluated three traditional steel bucking bars, three similarly shaped tungsten alloy bars, and three bars featuring spring-dampeners. For comparison the bucking bar vibrations were also assessed during three typical riveting tasks at a large aircraft maintenance facility. The bucking bars were rank-ordered in terms of unweighted and frequency-weighted acceleration measured at the hand-tool interface. The results suggest that the developed laboratory method is a reasonable technique for ranking bucking bar vibration emissions; the lab-based riveting simulations produced similar rankings to the workplace rankings. However, the laboratory-based acceleration averages were considerably lower than the workplace measurements. These observations suggest that the laboratory test results are acceptable for comparing and screening bucking bars, but the laboratory measurements should not be directly used for assessing the risk of workplace bucking bar vibration exposures. The newer bucking bar technologies exhibited significantly reduced vibrations compared to the traditional steel bars. The results of this study, together with other information such as rivet quality, productivity, tool

  17. The fatigue strength of riveted joints and lugs

    NASA Technical Reports Server (NTRS)

    Schijve, J

    1956-01-01

    This report deals with a number of tests on riveted joints and lugs for the primary purpose of comparing the several types of riveted joints and to study the effect of various factors on the fatigue strength of lugs. A check was made to ascertain whether or not an estimate of the fatigue life at a certain loading could be made from the dimensions of the joint and the fatigue data of the unnotched materials. Recommendations are made on the proportioning of joints to obtain better fatigue behavior.

  18. Self-Pierce Riveting of Three Aluminium Alloy and Mild Steel Sheets

    SciTech Connect

    Mori, K.; Abe, Y.; Sakai, S.; Kato, T.

    2010-06-15

    Three aluminium alloy and steel sheets were joined with a self-piercing rivet. Self-pierce riveting has the function of joining steel and aluminium alloys having very different melting points due to plastic joining. The requisites for joining the three sheets are the driving of the rivet leg through the middle sheet, the flaring of the rivet leg in the lower sheet and the prevention of the fracture of the lower sheet. The joinability for various combinations of the three sheets was determined. When the rivet leg is small, no driving through the middle sheet occurs, the lower sheet ruptures for a large rivet leg. In addition, 980 MPa high strength steel, mild steel and aluminium alloy sheets were joined by the self-pierce riveting.

  19. 14. View northeast. Detail of typical fish plating, riveted to ...

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

    14. View northeast. Detail of typical fish plating, riveted to top flange at center of each span. Same detail is found at center of both lower chords. - Walpole-Westminster Bridge, Spanning Connecticut River between Walpole, NH & Westminster, VT, Walpole, Cheshire County, NH

  20. View of riveted joint on tower support superstructure of Tensaw ...

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

    View of riveted joint on tower support superstructure of Tensaw River Bridge truss No. 2, looking southwest, showing deflector sheaves, roller and complex joint construction - Tensaw River Lift Bridge, Spanning Tensaw River at U.S. Highway 90, Mobile, Mobile County, AL

  1. View of riveted joint on tower support superstructure of Tensaw ...

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

    View of riveted joint on tower support superstructure of Tensaw River Bridge truss No. 2, looking northeast, showing deflector sheaves, roller and complex joint construction - Tensaw River Lift Bridge, Spanning Tensaw River at U.S. Highway 90, Mobile, Mobile County, AL

  2. Retention of riveted aluminum leg bands by wild turkeys

    USGS Publications Warehouse

    Diefenbach, Duane R.; Vreeland, Wendy C.; Casalena, Mary Jo; Schiavone, Michael V.

    2016-01-01

    In order for mark–recapture models to provide unbiased estimates of population parameters, it is critical that uniquely identifying tags or marks are not lost. We double-banded male and female wild turkeys with aluminum rivet bands and estimated the probability that a bird would be recovered with both bands <1–225 wk since banding (mean = 51.2 wk, SD = 44.0). We found that 100% of females (n = 37) were recovered with both bands. For males, we recovered 6 of 188 turkeys missing a rivet band for a retention probability of 0.984 (95% CI = 0.96–0.99). If male turkeys are double-banded with rivet bands the probability of recovering a turkey without any marks is <0.001. We failed to detect a change in band retention over time or differences between adults and juveniles. Given the low cost and high retention rates of rivet aluminum bands, we believe they are an effective marking technique for wild turkeys and, for most studies, will minimize any concern about the assumption that marks are not lost.

  3. UNIDENTIFIED CATENARY SUSPENSION BRIDGE, SHOWING RIVETED METAL PIERS UNDER CONSTRUCTION. ...

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

    UNIDENTIFIED CATENARY SUSPENSION BRIDGE, SHOWING RIVETED METAL PIERS UNDER CONSTRUCTION. NOTE APPROACH SPANS OF PIPE CONSTRUCTION IN RIGHT BACKGROUND. 3/4 VIEW FROM BELOW. - Clear Fork of Brazos River Suspension Bridge, Spanning Clear Fork of Brazos River at County Route 179, Albany, Shackelford County, TX

  4. Detail of south granite pier revealing riveted truss ends and ...

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

    Detail of south granite pier revealing riveted truss ends and iron footing plates on top of granite cap stones. View north - New York, New Haven & Hartford Railroad, Fort Point Channel Rolling Lift Bridge, Spanning Fort Point Channel, Boston, Suffolk County, MA

  5. UNIDENTIFIED CATENARY SUSPENSION BRIDGE, SHOWING COMPLETED RIVETED METAL PIERS AND ...

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

    UNIDENTIFIED CATENARY SUSPENSION BRIDGE, SHOWING COMPLETED RIVETED METAL PIERS AND WORKERS HOISTING SINGLE PIPE TOWER INTO PLACE. NOTE APPROACH SPANS OF PIPE CONSTRUCTION IN RIGHT BACKGROUND. ELEVATION VIEW. - Clear Fork of Brazos River Suspension Bridge, Spanning Clear Fork of Brazos River at County Route 179, Albany, Shackelford County, TX

  6. 49 CFR 230.34 - Riveted repairs and alterations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and... portions of the boiler. Prior to making riveted alterations on unstayed portions of the boiler, the steam... standard for boiler repairs. The steam locomotive owner and/or operator shall satisfy...

  7. 49 CFR 230.34 - Riveted repairs and alterations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and... portions of the boiler. Prior to making riveted alterations on unstayed portions of the boiler, the steam... standard for boiler repairs. The steam locomotive owner and/or operator shall satisfy...

  8. 49 CFR 230.34 - Riveted repairs and alterations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and... portions of the boiler. Prior to making riveted alterations on unstayed portions of the boiler, the steam... standard for boiler repairs. The steam locomotive owner and/or operator shall satisfy...

  9. 49 CFR 230.34 - Riveted repairs and alterations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and... portions of the boiler. Prior to making riveted alterations on unstayed portions of the boiler, the steam... standard for boiler repairs. The steam locomotive owner and/or operator shall satisfy...

  10. 49 CFR 230.34 - Riveted repairs and alterations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and... portions of the boiler. Prior to making riveted alterations on unstayed portions of the boiler, the steam... standard for boiler repairs. The steam locomotive owner and/or operator shall satisfy...

  11. 20. VIEW OF STEEL CROSSBEAMS, WOODEN STRINGERS, RIVETED CHANNEL POST, ...

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

    20. VIEW OF STEEL CROSSBEAMS, WOODEN STRINGERS, RIVETED CHANNEL POST, AND PIN-CONNECTED EYEBAR LOWER BRIDGE CHORD ALONG WESTERN ELEVATION, AT SOUTHWEST CORNER OF BRIDGE. FACING NORTHEAST. - Coverts Crossing Bridge, Spanning Mahoning River along Township Route 372 (Covert Road), New Castle, Lawrence County, PA

  12. 5. STANDPIPE STRUCTURE DETAIL SHOWING CONNECTIONS TO PENSTOCKS, RIVETED SECTIONAL ...

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

    5. STANDPIPE STRUCTURE DETAIL SHOWING CONNECTIONS TO PENSTOCKS, RIVETED SECTIONAL CONSTRUCTION OF TWO OF THE THREE ORIGINAL STANDPIPES (PHOTO RIGHT), WELDED SECTIONAL CONSTRUCTION OF FOURTH STANDPIPE, AND MODERN VENTILATION VALVES ON FIFTH PENSTOCK AT PHOTO LEFT CENTER BETWEEN FOURTH STANDPIPE AND ORIGINAL TWO. VIEW TO NORTHEAST. - Big Creek Hydroelectric System, Powerhouse 3 Penstock Standpipes, Big Creek, Big Creek, Fresno County, CA

  13. CLOSEUP OF TYPICAL BUILTUP, RIVETED AND PIN CONNECTED DECK TRUSS ...

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

    CLOSE-UP OF TYPICAL BUILT-UP, RIVETED AND PIN CONNECTED DECK TRUSS LOOKING UP AND NORTHEAST. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  14. UNIDENTIFIED CATENARY SUSPENSION BRIDGE ON RIVETED METAL PIERS, SHOWING HOWE ...

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

    UNIDENTIFIED CATENARY SUSPENSION BRIDGE ON RIVETED METAL PIERS, SHOWING HOWE PIPE TRUSS RAILING AND TRUSSED DECK BEAMS TYPICAL TO BRIDGES BUILT BY FLINN-MOYER COMPANY. TRIPODAL PIPE TOWERS RESEMBLE CLEAR FORK OF THE BRAZOS SUSPENSION BRIDGE’S TOWERS PRIOR TO ENCASEMENT IN CONCRETE. NOTE COLLAPSED TRUSS IN RIVER. ELEVATION VIEW. - Clear Fork of Brazos River Suspension Bridge, Spanning Clear Fork of Brazos River at County Route 179, Albany, Shackelford County, TX

  15. Effect of aging on mechanical properties of aluminum-alloy rivets

    NASA Technical Reports Server (NTRS)

    Roop, Frederick C

    1941-01-01

    Curves and tabular data present the results of strength tests made during and after 2 1/2 years of aging on rivets and rivet wire of 3/16-inch nominal diameter. The specimens were of aluminum alloy: 24S, 17S, and A17S of the duralumin type and 53S of the magnesium-silicide type.

  16. 46 CFR 126.160 - Tests and inspections during repairs or alterations, or during riveting, welding, burning, or...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... during riveting, welding, burning, or other hot work. 126.160 Section 126.160 Shipping COAST GUARD... § 126.160 Tests and inspections during repairs or alterations, or during riveting, welding, burning, or... riveting, welding, burning, or other hot work may commence. (c) Each examination must be conducted...

  17. 46 CFR 126.160 - Tests and inspections during repairs or alterations, or during riveting, welding, burning, or...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... during riveting, welding, burning, or other hot work. 126.160 Section 126.160 Shipping COAST GUARD... § 126.160 Tests and inspections during repairs or alterations, or during riveting, welding, burning, or... riveting, welding, burning, or other hot work may commence. (c) Each examination must be conducted...

  18. 46 CFR 126.160 - Tests and inspections during repairs or alterations, or during riveting, welding, burning, or...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... during riveting, welding, burning, or other hot work. 126.160 Section 126.160 Shipping COAST GUARD... § 126.160 Tests and inspections during repairs or alterations, or during riveting, welding, burning, or... riveting, welding, burning, or other hot work may commence. (c) Each examination must be conducted...

  19. 46 CFR 126.160 - Tests and inspections during repairs or alterations, or during riveting, welding, burning, or...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... during riveting, welding, burning, or other hot work. 126.160 Section 126.160 Shipping COAST GUARD... § 126.160 Tests and inspections during repairs or alterations, or during riveting, welding, burning, or... riveting, welding, burning, or other hot work may commence. (c) Each examination must be conducted...

  20. 46 CFR 126.160 - Tests and inspections during repairs or alterations, or during riveting, welding, burning, or...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... during riveting, welding, burning, or other hot work. 126.160 Section 126.160 Shipping COAST GUARD... § 126.160 Tests and inspections during repairs or alterations, or during riveting, welding, burning, or... riveting, welding, burning, or other hot work may commence. (c) Each examination must be conducted...

  1. Rivet-fastener belt splices reduce conveyor downtime

    SciTech Connect

    Not Available

    1982-11-01

    At Sahara Coal Co's No. 21 Mine in Illinois some 18 miles of conveyor belting are in underground use bringing coal from the faces to a main haulage conveyor which transports the coal to the surface. The belt material is nylon carcass with rubber cover. Because of relatively low roof clearance, thinner belt than is typically used underground is employed, since a 500 ft roll of thicker belting would be unable to negotiate low-clearance entries. This thinner belt material could not be spliced using conventional fasteners, but solid-plate rivetted splicing has been found to be satisfactory.

  2. Analysis of the rivets from the RMS Titanic using experimental and theoretical techniques

    NASA Astrophysics Data System (ADS)

    Hooper, Jennifer Jo

    Earlier studies of Titanic wrought iron rivets revealed an anisotropic, inhomogeneous composite material composed of glassy iron silicate (slag) particles embedded in a ferrite matrix. Micrographs indicated a directional character to the slag "stringers" that follows the method of processing---aligned parallel to the shaft in the center of the rivet, but oriented perpendicular to the shaft within the inner section of each head. It was proposed that the re-orientation of large slag particles in the rivet head weakened this region, predisposing the rivets to fail as a result of collision with the iceberg. Using quantitative metallography, mechanical testing, and a combination of modeling techniques, this hypothesis was tested using 35 Titanic rivets and additional contemporary wrought iron. Results revealed that the wrought iron microstructure showed a high slag content that was very coarse and unevenly distributed. Results from micro structural, chemical and mechanical analysis, as well as supporting historical evidence, suggested that two types of rivets, both wrought iron and steel, were used on the Titanic. Tensile testing results indicated that the longitudinal orientation in wrought iron possesses an average of 20% higher tensile strength and nearly four times the ductility of the transverse orientation. Results for Titanic rivet steel suggest a 100MPa enhancement in yield strength and tensile strength over wrought iron. Sequential imaging during mechanical testing, supported by micromechanical modeling predictions, indicated that the mechanical behavior of wrought iron is strongly affected by the orientation, distribution and content of slag within the matrix. Finite element analysis of a wrought iron rivet with anisotropic properties demonstrated that, because of poor ductility produced by the re-orientation of slag within the head, a Titanic rivet could not withstand a 5mm displacement of the hull's steel plates. Due to its low ultimate tensile strength, the

  3. Effects of process parameters on friction self-piercing riveting of dissimilar materials

    DOE PAGESBeta

    Liu, Xun; Lim, Yong Chae; Li, Yongbing; Tang, Wei; Ma, Yunwu; Feng, Zhili; Ni, Jun

    2016-05-24

    In the present work, a recently developed solid state joining technique, Friction self-piercing riveting (F-SPR), has been applied for joining high strength aluminum alloy AA7075-T6 to magnesium alloy AZ31B. The process was performed on a specially designed machine where the spindle can achieve the motion of sudden stop. Effects of rivet rotating rate and punch speed on axial plunge force, torque, joint microstructure and quality have been analyzed systematically. During F-SPR, higher rotating rate and slower punch speed can reduce axial force and torque, which correspondingly results in a slightly smaller interlock between rivet leg and joined materials. Improved localmore » flowability of both aluminum and magnesium alloys under a higher rotating speed results in a thicker aluminum layer surrounding the rivet leg, where formation of Al-Mg intermetallics was observed. Equivalent joint strength obtained in this study are higher than the yield strength of the AZ31 Mg alloy. One of the tensile failure modes is the rivet fracture, which is due to local softening of rivet leg from frictional heat. Lastly, other two failure modes include rivet pullout and shear through of bottom sheet.« less

  4. A robust multi-frequency mixing algorithm for suppression of rivet signal in GMR inspection of riveted structures

    NASA Astrophysics Data System (ADS)

    Safdernejad, Morteza S.; Karpenko, Oleksii; Ye, Chaofeng; Udpa, Lalita; Udpa, Satish

    2016-02-01

    The advent of Giant Magneto-Resistive (GMR) technology permits development of novel highly sensitive array probes for Eddy Current (EC) inspection of multi-layer riveted structures. Multi-frequency GMR measurements with different EC pene-tration depths show promise for detection of bottom layer notches at fastener sites. However, the distortion of the induced magnetic field due to flaws is dominated by the strong fastener signal, which makes defect detection and classification a challenging prob-lem. This issue is more pronounced for ferromagnetic fasteners that concentrate most of the magnetic flux. In the present work, a novel multi-frequency mixing algorithm is proposed to suppress rivet signal response and enhance defect detection capability of the GMR array probe. The algorithm is baseline-free and does not require any assumptions about the sample geometry being inspected. Fastener signal suppression is based upon the random sample consensus (RANSAC) method, which iteratively estimates parameters of a mathematical model from a set of observed data with outliers. Bottom layer defects at fastener site are simulated as EDM notches of different length. Performance of the proposed multi-frequency mixing approach is evaluated on finite element data and experimental GMR measurements obtained with unidirectional planar current excitation. Initial results are promising demonstrating the feasibility of the approach.

  5. Self-Pierce Riveting Through 3 Sheet Metal Combinations

    SciTech Connect

    Andersson, Roger; Jonason, Paul; Pettersson, Tommy

    2011-05-04

    One way to reduce the CO{sub 2} emissions in automotives is to reduce the weight of the Body-In-White. One easy to achieve the weight reduction is to replace steel sheet materials with Al alloys, which is 3 times lighter. One issue is the joining process, especially with combinations between steel grades and AL alloys. Example of combination of mixed material combinations (Al-steel) might be found in the door structure. The reason is because of the AL alloys worthier crash performance so the automotive manufacturer might want to use crash impact beams made by high strength steels in a AL intensive door structure. The joining process between aluminum and steel are problematic due it's not possible to use traditional spot-welding technologies due to the materials total difference in microstructure characteristics as well thermal properties. To overcome this issue then mechanical as well adhesion joining are frequently used. This paper describes a development process and subsequently analysis of a self-pierce rivet (SPR) process between 3 sheet metal combinations. The multi-material combinations in this study were a combination of ultra high strength steels sheets (DP1000) and a Al-alloy (AA 6014). The analysis of the SPR process, in sense of mechanical strengths, has been done by peel- and shear tests. To reduce the amount of future physical tests a virtual FE-model has been developed for the process. This FE model of the process has been subsequently used to analyze the mechanical strength during plastic deformation. By using inverse analysis a correct contact algorithm has been evaluated that would predict the binding force between the rivet and sheet under a deformation process. With this new virtual model it will not only possible to analyze and develop the SPR process but also to achieve the final strength of the joint.

  6. Mechanical joining with self piercing solid-rivets at elevated tool velocities

    SciTech Connect

    Neugebauer, R.; Jesche, F.; Kraus, C.; Hensel, S.

    2011-05-04

    In the present paper the influence of a higher setting velocity in the joining process of self piercing solid-rivets is shown. In the conventional process tool velocities well below 1 m/s are common. The present research results show the potential of increasing them in the range of about 5 m/s. The results are especially relevant for joining high-strength steels. These steel sheets often cause problems in the process of riveting mixed materials, e. g. aluminium-steel compound. The high strength of the steel sometimes leads to undesirable material flow in the joining process or unwanted burr development. These effects, which are described in detail in the article, can be reduced significantly for the investigated cases by the use of higher tool velocities. Using a high speed camera and a load cell, a test setup based on a drop tower was realized. It was used to time the force signals and the motion profile of the high speed riveting process. The results of the force analysis show an oscillating force progression. Within a numerical research the principal effects influencing the results of the riveting process can be shown. It was found that the pulse-like force transmission between riveting machine and punch, results in various vibrations especially of long and thin tool parts. Hence the rivet penetrates the sheet metal with non-uniform velocities. As a result the early indentation of die into the lower sheet metal at the beginning of the process is reduced, so that the final process step provides a sufficient material flow into the circular rivet groove. A strain-rate dependent process model with elastic tool properties and consideration of inertia effects is presented.

  7. The Increase in Frictional Resistance Caused by Various Types of Rivet Heads as Determined by Tests of Planing Surfaces

    NASA Technical Reports Server (NTRS)

    Truscott, Starr; Parkinson, J B

    1938-01-01

    The increase in the frictional resistance of a surface caused by the presence of rivet heads was determined by towing four planing surfaces of the same dimensions. One surface was smooth and represented a surface without rivet heads or one with perfectly flush countersunk rivets. The other three surfaces were each fitted with the same number of full-size rivet heads but of a different type arranged in the same pattern on each surface. The surfaces were towed at speeds representative of the high water speeds encountered by seaplanes during take-off and the range of Reynolds Number covered by the test was from 4 x 10(exp 6) to 18 x 10(exp 6). The rivet heads investigated were oval countersunk, brazier, and round for rivets having shanks 5/32 inch in diameter. The oval countersunk heads were sunk below the surface by dimpling the plating around them. The results of the tests showed that, for the rivet heads investigated, the increase in the friction coefficient of the surface is directly proportional to the height of the rivet head. The order of merit in regard to low resistance is flush countersunk, oval countersunk (whether sunk below the surface or not), brazier, and round.

  8. A 3D Model for Eddy Current Inspection in Aeronautics: Application to Riveted Structures

    NASA Astrophysics Data System (ADS)

    Paillard, S.; Pichenot, G.; Lambert, M.; Voillaume, H.; Dominguez, N.

    2007-03-01

    Eddy current technique is currently an operational tool used for fastener inspection which is an important issue for the maintenance of aircraft structures. The industry calls for faster, more sensitive and reliable NDT techniques for the detection and characterization of potential flaws nearby rivet. In order to reduce the development time and to optimize the design and the performances assessment of an inspection procedure, the CEA and EADS have started a collaborative work aiming at extending the modeling features of the CIVA non destructive simulation plat-form in order to handle the configuration of a layered planar structure with a rivet and an embedded flaw nearby. Therefore, an approach based on the Volume Integral Method using the Green dyadic formalism which greatly increases computation efficiency has been developed. The first step, modeling the rivet without flaw as a hole in a multi-stratified structure, has been reached and validated in several configurations with experimental data.

  9. The use of rivets for electrical resistance measurement on carbon fibre-reinforced thermoplastics

    NASA Astrophysics Data System (ADS)

    DeBaere, I.; Van Paepegem, W.; Degrieck, J.

    2007-10-01

    The use of fibre-reinforced thermoplastics, for example in the aeronautical industry, is increasing rapidly. Therefore, there is an increasing need for in situ monitoring tools, which preferably have limited influence on the behaviour of the material and which are easy to use. Furthermore, in the aeronautical industry composites are very often attached with rivets. In this study, the possibility of the use of rivets as contact electrodes for electrical resistance measurement is explored. The material used is a carbon fibre-reinforced polyphenylene sulphide. First, the set-up used is discussed. Then, static tensile tests on the laminate are performed. The possible influence of an extensometer on the measurements is examined. Furthermore, failure predictability is assessed. It may be concluded that the proposed set-up with the rivets can be used for electrical resistance measurement, with the ability to predict failure, and that the extensometer has a negative influence on the resistance measurement.

  10. 7. TYPICAL INTERIOR AND BOTTOM OF EMPTY 14.5FOOTDIAMETER RIVETED STEEL ...

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

    7. TYPICAL INTERIOR AND BOTTOM OF EMPTY 14.5-FOOT-DIAMETER RIVETED STEEL SOAP KETTLE, WITH STEAM COILS; VIEW DOWN FROM KETTLE TOP, FIFTH FLOOR, EAST BAY, THIRD KETTLE FROM SOUTH - Colgate & Company Jersey City Plant, Building No. B-13, 48-50 Grand Street, Jersey City, Hudson County, NJ

  11. Tensile and fatigue behaviour of self-piercing rivets of CFRP to aluminium for automotive application

    NASA Astrophysics Data System (ADS)

    Kang, J.; Rao, H.; Zhang, R.; Avery, K.; Su, X.

    2016-07-01

    In this study, the tensile and fatigue behaviour of self-piercing rivets (SPRs) in carbon fibre reinforced plastic (CFRP) to aluminium 6111 T82 alloys were evaluated. An average maximum lap-shear tensile load capacity of 3858 N was achieved, which is comparable to metal-to-metal SPR lap-shear joints. The CFRP-Al SPRs failed in lap-shear tension due to pull-out of the rivet head from the CFRP upper sheet. The CFRP-Al SPR lap- shear specimens exhibited superior fatigue life compared to previously studied aluminium-to- aluminium SPR lap-shear joints. The SPR lap-shear joints under fatigue loads failed predominantly due to kinked crack growth along the width of the bottom aluminium sheet. The fatigue cracks initiated in the plastically deformed region of the aluminium sheet close to the rivet shank in the rivet-sheet interlock region. Scatter in fatigue life and failure modes was observed in SPR lap-shear specimens tested close to maximum tensile load.

  12. 16. DETAIL, L1 JOINT, FROM BELOW AND SOUTH, SHOWING RIVETED ...

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

    16. DETAIL, L1 JOINT, FROM BELOW AND SOUTH, SHOWING RIVETED CONNECTION, AND CONFIGURATION OF VERTICAL U1-I1, LOWER CHORD AND FLOOR SYSTEM - Glendale Road Bridge, Spanning Deep Creek Lake on Glendale Road, McHenry, Garrett County, MD

  13. 13. DETAIL, U1 JOINT, FROM BELOW AND SOUTH, SHOWING RIVETED ...

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

    13. DETAIL, U1 JOINT, FROM BELOW AND SOUTH, SHOWING RIVETED CONNECTION, AND INTERSECTION OF END POST, VERTICAL, DIAGONAL AND UPPER CHORD MEMBERS AND LATERAL BRACING - Glendale Road Bridge, Spanning Deep Creek Lake on Glendale Road, McHenry, Garrett County, MD

  14. 14. DETAIL, U3 JOINT, FROM BELOW AND SOUTH, SHOWING RIVETED ...

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

    14. DETAIL, U3 JOINT, FROM BELOW AND SOUTH, SHOWING RIVETED CONNECTION, AND INTERSECTION OF TOP CHORD, VERTICAL U3-L3, DIAGONALS, AND LATERAL BRACING INCLUDING DOUBLE ANGLES WITH LACING BARS - Glendale Road Bridge, Spanning Deep Creek Lake on Glendale Road, McHenry, Garrett County, MD

  15. Numerical analysis of static performance comparison of friction stir welded versus riveted 2024-T3 aluminum alloy stiffened panels

    NASA Astrophysics Data System (ADS)

    Shao, Qing; He, Yuting; Zhang, Teng; Wu, Liming

    2014-07-01

    Most researches on the static performance of stiffened panel joined by friction stir welding(FSW) mainly focus on the compression stability rather than shear stability. To evaluate the potential of FSW as a replacement for traditional rivet fastening for stiffened panel assembly in aviation application, finite element method(FEM) is applied to compare compression and shear stability performances of FSW stiffened panels with stability performances of riveted stiffened panels. FEMs of 2024-T3 aluminum alloy FSW and riveted stiffened panels are developed and nonlinear static analysis method is applied to obtain buckling pattern, buckling load and load carrying capability of each panel model. The accuracy of each FEM of FSW stiffened panel is evaluated by stability experiment of FSW stiffened panel specimens with identical geometry and boundary condition and the accuracy of each FEM of riveted stiffened panel is evaluated by semi-empirical calculation formulas. It is found that FEMs without considering weld-induced initial imperfections notably overestimate the static strengths of FSW stiffened panels. FEM results show that, buckling patterns of both FSW and riveted compression stiffened panels represent local buckling of plate between stiffeners. The initial buckling waves of FSW stiffened panel emerge uniformly in each plate between stiffeners while those of riveted panel mainly emerge in the mid-plate. Buckling patterns of both FSW and riveted shear stiffened panels represent local buckling of plate close to the loading corner. FEM results indicate that, shear buckling of FSW stiffened panel is less sensitive to the initial imperfections than compression buckling. Load carrying capability of FSW stiffened panel is less sensitive to the initial imperfections than initial buckling. It can be concluded that buckling loads of FSW panels are a bit lower than those of riveted panels whereas carrying capabilities of FSW panels are almost equivalent to those of riveted

  16. The Effect of Rivet Heads on the Characteristics of a 6 by 36 Foot Clark Y Metal Airfoil

    NASA Technical Reports Server (NTRS)

    Dearborn, Clinton H

    1933-01-01

    An investigation was conducted in the N.A.C.A. full-scale wind tunnel to determine the effects of exposed rivet heads on the aerodynamic characteristics of a metal-covered 6 by 36 foot Clasky airfoil. Lead punching simulating 1/8inch rivet heads were attached in full-span rows at a pitch of 1 inch at various chord positions. Tests were made at velocities varying from 40 to 120 miles per hour to investigate the scale effect. Rivets at the 5 percent chord position the upper surface of the airfoil produced the greatest increase in drag for a single row. Nine rows of rivets on both surfaces, simulating rivet spacing of multispan construction, increased the drag coefficients by a constant amount at velocities between 100 and 120 miles per hour. Accordingly, if rivets spaced the same as those on the test airfoil were used on a Clark Y wing of 300 square feet area and operated at 200 miles per hour, the drag would be increased over that for the smooth wing by 55 pounds and the power required would be increased by 29 horsepower.

  17. Simulation of Intersection Rivet at Non-signalized Intersection in Housing Scheme

    NASA Astrophysics Data System (ADS)

    Nazmi, Mohd; Takaba, Sadao; Ohno, Sumio; Yusoff, Mohd Nazaruddin

    Accident in the residential area are become serious case in Malaysia. Most of the incidents occur among pedestrians, bicycles, motorcycles and vehicles. Our research purpose is to avoid collision at the non-signalized intersection in the housing scheme. We committed to reduce injuries and increase pedestrians' safety. Our research provides important information that can help driver predict common problems and take steps to prevent collisions. Intersection rivet is proposed for this matter. This type of signal system can prevent any accident in a dangerous non-signalized intersection. Simulation tools and systems are developed to find and solve the problem in order to decrease any fatal incident. Investigation data were used to simulate the situation more precisely. The result will be effective as reference to set the parameter of control system of the intersection rivet.

  18. Two-sided friction stir riveting by extrusion: A process for joining dissimilar materials

    DOE PAGESBeta

    Evans, William T.; Cox, Chase D.; Strauss, Alvin M.; Cook, George E.; Gibson, Brian T.

    2016-06-25

    Two-sided friction stir riveting (FSR) by extrusion is an innovative process developed to rapidly, efficiently, and securely join dissimilar materials. This process extends a previously developed one sided friction stir extrusion process to create a strong and robust joint by producing a continuous, rivet-like structure through a preformed hole in one of the materials with a simultaneous, two-sided friction stir spot weld. The two-sided FSR by extrusion process securely joins the dissimilar materials together and effectively locks them in place without the use of any separate materials or fasteners. Lastly, in this paper we demonstrate the process by joining aluminummore » to steel and illustrate its potential application to automotive and aerospace manufacturing processes.« less

  19. A Practical Engineering Approach to Predicting Fatigue Crack Growth in Riveted Lap Joints

    NASA Technical Reports Server (NTRS)

    Harris, C. E.; Piascik, R. S.; Newman, J. C., Jr.

    2000-01-01

    An extensive experimental database has been assembled from very detailed teardown examinations of fatigue cracks found in rivet holes of fuselage structural components. Based on this experimental database, a comprehensive analysis methodology was developed to predict the onset of widespread fatigue damage in lap joints of fuselage structure. Several computer codes were developed with specialized capabilities to conduct the various analyses that make up the comprehensive methodology. Over the past several years, the authors have interrogated various aspects of the analysis methods to determine the degree of computational rigor required to produce numerical predictions with acceptable engineering accuracy. This study led to the formulation of a practical engineering approach to predicting fatigue crack growth in riveted lap joints. This paper describes the practical engineering approach and compares predictions with the results from several experimental studies.

  20. Detection of Fatigue Cracks at Rivets with Self-Nulling Probe

    NASA Technical Reports Server (NTRS)

    Wincheski, Buzz; Fulton, Jim; Nath, Shridhar; Namkung, Min

    1994-01-01

    A new eddy current probe developed at NASA Langley Research Center has been used to detect small cracks at rivets in aircraft lap splices [1]. The device has earlier been used to detect isolated fatigue cracks with a minimum detectable flaw size of roughly 1/2 to 1/3 the diameter of the probe [2]. The present work shows that the detectable flaw size for cracks originating at rivets can be greatly improved upon from that of isolated flaws. The use of a rotating probe method combined with spatial filtering has been used to detect 0.18 cm EDM notches, as measured from the rivet shank, with a 1.27 cm diameter probe and to detect flaws buried under the rivet head, down to a length of 0.076 cm, using a 0.32 cm diameter probe. The Self-Nulling Electromagnetic Flaw Detector induces a high density eddy current ring in the sample under test. A ferromagnetic flux focusing lens is incorporated such that in the absence of any inhomogeneities in the material under test only a minimal magnetic field will reach the interior of the probe. A magnetometer (pickup coil) located in the center of the probe therefore registers a null voltage in the absence of material defects. When a fatigue crack or other discontinuity is present in the test article the path of the eddy currents in the material is changed. The magnetic field associated with these eddy currents then enter into the interior of the probe, producing a large output voltage across the pickup coil leads. Further

  1. Experimental Analysis of Stiffness of the Riveted Steel Railway Bridge Deck Members' Joints

    NASA Astrophysics Data System (ADS)

    Gocál, Jozef; Hlinka, Richard; Jošt, Jozef; Bahleda, František

    2014-12-01

    The paper deals with the real behaviour of the riveted steel railway bridge deck members' connections with respect to their bending stiffness. Attention is paid to the stringer-to-cross beam connection as well as the cross beam-to-main girder connection. The stiffness of the two connections is investigated on the basis of evaluation of the experimentally determined stress response of the observed structural members to the actual traffic load on an existing railway bridge.

  2. Torsional moment to failure for carbon fibre polysulphone expandable rivets as compared with stainless steel screws for carbon fibre-reinforced epoxy fracture plate fixation.

    PubMed

    Sell, P J; Prakash, R; Hastings, G W

    1989-04-01

    A method of securing carbon fibre-reinforced epoxy bone plates with carbon fibre polysulphone expanding rivets was investigated. Six carbon fibre-reinforced epoxy bone plates were secured to rods with carbon fibre polysulphone rivets and six were secured with standard cortical stainless steel screws. These constructions were then subjected to pure torsional load to failure. The carbon fibre expandable rivets failed at a greater torsional moment.

  3. The Load Distribution in Bolted or Riveted Joints in Light-Alloy Structures

    NASA Technical Reports Server (NTRS)

    Vogt, F.

    1947-01-01

    This report contains a theoretical discussion of the load distribution in bolted or riveted joints in light-alloy structures which is applicable not only for loads below the limit of proportionality but also for loads above this limit. The theory is developed for double and single shear joints. The methods given are illustrated by numerical examples and the values assumed for the bolt (or rivet) stiffnesses are based partly on theory and partly on known experimental values. It is shown that the load distribution does not vary greatly with the bolt (or rivet) stiffnesses and that for design purposes it is usually sufficient to know their order of magnitude. The theory may also be directly used for spot-welded structures and, with small modifications, for seam-welded structures, The computational work involved in the methods described is simple and may be completed in a reasonable time for most practical problems. A summary of earlier theoretical and experimental investigations on the subject is included in the report.

  4. Multifrequency Eddy Current Inspection of Corrosion in Clad Aluminum Riveted Lap Joints and Its Effect on Fatigue Life

    SciTech Connect

    Okafor, A. C.; Natarajan, S.

    2007-03-21

    Aging aircraft are prone to corrosion damage and fatigue cracks in riveted lap joints of fuselage skin panels. This can cause catastrophic failure if not detected and repaired. Hence detection of corrosion damage and monitoring its effect on structural integrity are essential. This paper presents multifrequency eddy current (EC) inspection of corrosion damage and machined material loss defect in clad A1 2024-T3 riveted lap joints and its effect on fatigue life. Results of eddy current inspection, corrosion product removal and fatigue testing are presented.

  5. Multifrequency Eddy Current Inspection of Corrosion in Clad Aluminum Riveted Lap Joints and Its Effect on Fatigue Life

    NASA Astrophysics Data System (ADS)

    Okafor, A. C.; Natarajan, S.

    2007-03-01

    Aging aircraft are prone to corrosion damage and fatigue cracks in riveted lap joints of fuselage skin panels. This can cause catastrophic failure if not detected and repaired. Hence detection of corrosion damage and monitoring its effect on structural integrity are essential. This paper presents multifrequency eddy current (EC) inspection of corrosion damage and machined material loss defect in clad A1 2024-T3 riveted lap joints and its effect on fatigue life. Results of eddy current inspection, corrosion product removal and fatigue testing are presented.

  6. Optimization and Validation of Rotating Current Excitation with GMR Array Sensors for Riveted Structures Inspection.

    PubMed

    Ye, Chaofeng; Udpa, Lalita; Udpa, Satish

    2016-09-16

    In eddy current non-destructive testing of a multi-layered riveted structure, rotating current excitation, generated by orthogonal coils, is advantageous in providing sensitivity to defects of all orientations. However, when used with linear array sensors, the exciting magnetic flux density ( B x ) of the orthogonal coils is not uniform over the sensor region, resulting in an output signal magnitude that depends on the relative location of the defect to the sensor array. In this paper, the rotating excitation coil is optimized to achieve a uniform B x field in the sensor array area and minimize the probe size. The current density distribution of the coil is optimized using the polynomial approximation method. A non-uniform coil design is derived from the optimized current density distribution. Simulation results, using both an optimized coil and a conventional coil, are generated using the finite element method (FEM) model. The signal magnitude for an optimized coil is seen to be more robust with respect to offset of defects from the coil center. A novel multilayer coil structure, fabricated on a multi-layer printed circuit board, is used to build the optimized coil. A prototype probe with the optimized coil and 32 giant magnetoresistive (GMR) sensors is built and tested on a two-layer riveted aluminum sample. Experimental results show that the optimized probe has better defect detection capability compared with a conventional non-optimized coil.

  7. Optimization and Validation of Rotating Current Excitation with GMR Array Sensors for Riveted Structures Inspection

    PubMed Central

    Ye, Chaofeng; Udpa, Lalita; Udpa, Satish

    2016-01-01

    In eddy current non-destructive testing of a multi-layered riveted structure, rotating current excitation, generated by orthogonal coils, is advantageous in providing sensitivity to defects of all orientations. However, when used with linear array sensors, the exciting magnetic flux density (Bx) of the orthogonal coils is not uniform over the sensor region, resulting in an output signal magnitude that depends on the relative location of the defect to the sensor array. In this paper, the rotating excitation coil is optimized to achieve a uniform Bx field in the sensor array area and minimize the probe size. The current density distribution of the coil is optimized using the polynomial approximation method. A non-uniform coil design is derived from the optimized current density distribution. Simulation results, using both an optimized coil and a conventional coil, are generated using the finite element method (FEM) model. The signal magnitude for an optimized coil is seen to be more robust with respect to offset of defects from the coil center. A novel multilayer coil structure, fabricated on a multi-layer printed circuit board, is used to build the optimized coil. A prototype probe with the optimized coil and 32 giant magnetoresistive (GMR) sensors is built and tested on a two-layer riveted aluminum sample. Experimental results show that the optimized probe has better defect detection capability compared with a conventional non-optimized coil. PMID:27649202

  8. Optimization and Validation of Rotating Current Excitation with GMR Array Sensors for Riveted Structures Inspection.

    PubMed

    Ye, Chaofeng; Udpa, Lalita; Udpa, Satish

    2016-01-01

    In eddy current non-destructive testing of a multi-layered riveted structure, rotating current excitation, generated by orthogonal coils, is advantageous in providing sensitivity to defects of all orientations. However, when used with linear array sensors, the exciting magnetic flux density ( B x ) of the orthogonal coils is not uniform over the sensor region, resulting in an output signal magnitude that depends on the relative location of the defect to the sensor array. In this paper, the rotating excitation coil is optimized to achieve a uniform B x field in the sensor array area and minimize the probe size. The current density distribution of the coil is optimized using the polynomial approximation method. A non-uniform coil design is derived from the optimized current density distribution. Simulation results, using both an optimized coil and a conventional coil, are generated using the finite element method (FEM) model. The signal magnitude for an optimized coil is seen to be more robust with respect to offset of defects from the coil center. A novel multilayer coil structure, fabricated on a multi-layer printed circuit board, is used to build the optimized coil. A prototype probe with the optimized coil and 32 giant magnetoresistive (GMR) sensors is built and tested on a two-layer riveted aluminum sample. Experimental results show that the optimized probe has better defect detection capability compared with a conventional non-optimized coil. PMID:27649202

  9. Three-Dimensional Geometric Nonlinear Contact Stress Analysis of Riveted Joints

    NASA Technical Reports Server (NTRS)

    Shivakumar, Kunigal N.; Ramanujapuram, Vivek

    1998-01-01

    The problems associated with fatigue were brought into the forefront of research by the explosive decompression and structural failure of the Aloha Airlines Flight 243 in 1988. The structural failure of this airplane has been attributed to debonding and multiple cracking along the longitudinal lap splice riveted joint in the fuselage. This crash created what may be termed as a minor "Structural Integrity Revolution" in the commercial transport industry. Major steps have been taken by the manufacturers, operators and authorities to improve the structural airworthiness of the aging fleet of airplanes. Notwithstanding, this considerable effort there are still outstanding issues and concerns related to the formulation of Widespread Fatigue Damage which is believed to have been a contributing factor in the probable cause of the Aloha accident. The lesson from this accident was that Multiple-Site Damage (MSD) in "aging" aircraft can lead to extensive aircraft damage. A strong candidate in which MSD is highly probable to occur is the riveted lap joint.

  10. Study of eddy currents non destructive testing system in riveted assemblies

    SciTech Connect

    Rasolonjanahary, J.L.; Thollon, F.; Burais, N.; Brunotte, X.

    1996-05-01

    In order to optimize eddy current sensors, the authors have to simulate electromagnetic phenomena to predict sensors` response. 2D and 3D codes can be used but what kind of result can be expected from each of these codes? In this paper, performances of 3D formulations are testing using FEM package Flux3d. Adapted coupled formulations and boundary conditions are used to study eddy currents perturbation by flaws in aircraft riveted assemblies. Physical informations about the influence of flaw depth are obtained. The 3D calculations allow one to choose the most adapted measurement quantity and to define the position of the measurement sensors. Then, for optimizing the sensor, 2D FEM package Fissure is used taking into account the 3D results.

  11. The Characteristics of Fatigue Damage in the Fuselage Riveted Lap Splice Joint

    NASA Technical Reports Server (NTRS)

    Piascik, Robert S.; Willard, Scott A.

    1997-01-01

    An extensive data base has been developed to form the physical basis for new analytical methodology to predict the onset of widespread fatigue damage in the fuselage lap splice joint. The results of detailed destructive examinations have been cataloged to describe the physical nature of MSD in the lap splice joint. ne catalog includes a detailed description, e.g., crack initiation, growth rates, size, location, and fracture morphology, of fatigue damage in the fuselage lap splice joint structure. Detailed examinations were conducted on a lap splice joint panel removed from a full scale fuselage test article after completing a 60,000 cycle pressure test. The panel contained a four bay region that exhibited visible outer skin cracks and regions of crack link-up along the upper rivet row. Destructive examinations revealed undetected fatigue damage in the outer skin, inner skin, and tear strap regions. Outer skin fatigue cracks were found to initiate by fretting damage along the faying surface. The cracks grew along the faying surface to a length equivalent to two to three skin thicknesses before penetrating the outboard surface of the outer skin. Analysis of fracture surface marker bands produced during full scale testing revealed that all upper rivet row fatigue cracks contained in a dim bay region grow at similar rates; this important result suggests that fracture mechanics based methods can be used to predict the growth of outer skin fatigue cracks in lap splice structure. Results are presented showing the affects of MSD and out-of-plane pressure loads on outer skin crack link-up.

  12. In vivo degradation of a new concept of magnesium-based rivet-screws in the minipig mandibular bone.

    PubMed

    Schaller, Benoit; Saulacic, Nikola; Beck, Stefan; Imwinkelried, Thomas; Goh, Bee Tin; Nakahara, Ken; Hofstetter, Willy; Iizuka, Tateyuki

    2016-12-01

    Self-tapping of magnesium screws in hard bone may be a challenge due to the limited torsional strength of magnesium alloys in comparison with titanium. To avoid screw failure upon implantation, the new concept of a rivet-screw was applied to a WE43 magnesium alloy. Hollow cylinders with threads on the outside were expanded inside drill holes of minipig mandibles. During the expansion with a hexagonal mandrel, the threads engaged the surrounding bone and the inside of the screw transformed into a hexagonal screw drive to allow further screwing in or out of the implant. The in vivo degradation of the magnesium implants and the performance of the used coating were studied in a human standard-sized animal model. Four magnesium alloy rivet-screws were implanted in each mandible of 12 minipigs. Six animals received the plasmaelectrolytically coated magnesium alloy implants; another six received the uncoated magnesium alloy rivet-screws. Two further animals received one titanium rivet-screw each as control. In vivo radiologic examination was performed at one, four, and eight weeks. Euthanasia was performed for one group of seven animals (three animals with coated, three with uncoated magnesium alloy implants and one with titanium implant) at 12weeks and for the remaining seven animals at 24weeks. After euthanasia, micro-computed tomography and histological examination with histomorphometry were performed. Significantly less void formation as well as higher bone volume density (BV/TV) and bone-implant contact area (BIC) were measured around the coated implants compared to the uncoated ones. The surface coating was effective in delaying degradation despite plastic deformation. The results showed potential for further development of magnesium hollow coated screws for bone fixation.

  13. In vivo degradation of a new concept of magnesium-based rivet-screws in the minipig mandibular bone.

    PubMed

    Schaller, Benoit; Saulacic, Nikola; Beck, Stefan; Imwinkelried, Thomas; Goh, Bee Tin; Nakahara, Ken; Hofstetter, Willy; Iizuka, Tateyuki

    2016-12-01

    Self-tapping of magnesium screws in hard bone may be a challenge due to the limited torsional strength of magnesium alloys in comparison with titanium. To avoid screw failure upon implantation, the new concept of a rivet-screw was applied to a WE43 magnesium alloy. Hollow cylinders with threads on the outside were expanded inside drill holes of minipig mandibles. During the expansion with a hexagonal mandrel, the threads engaged the surrounding bone and the inside of the screw transformed into a hexagonal screw drive to allow further screwing in or out of the implant. The in vivo degradation of the magnesium implants and the performance of the used coating were studied in a human standard-sized animal model. Four magnesium alloy rivet-screws were implanted in each mandible of 12 minipigs. Six animals received the plasmaelectrolytically coated magnesium alloy implants; another six received the uncoated magnesium alloy rivet-screws. Two further animals received one titanium rivet-screw each as control. In vivo radiologic examination was performed at one, four, and eight weeks. Euthanasia was performed for one group of seven animals (three animals with coated, three with uncoated magnesium alloy implants and one with titanium implant) at 12weeks and for the remaining seven animals at 24weeks. After euthanasia, micro-computed tomography and histological examination with histomorphometry were performed. Significantly less void formation as well as higher bone volume density (BV/TV) and bone-implant contact area (BIC) were measured around the coated implants compared to the uncoated ones. The surface coating was effective in delaying degradation despite plastic deformation. The results showed potential for further development of magnesium hollow coated screws for bone fixation. PMID:27612710

  14. Ultrasonic inspection of multiple-rivet-hole lap joint cracks using global analysis with local finite element approach

    NASA Astrophysics Data System (ADS)

    Bhuiyan, Yeasin; Shen, Yanfeng; Giurgiutiu, Victor

    2016-04-01

    Ultrasonic inspection of multiple-rivet-hole lap joint cracks has been introduced using combined analytical and finite element approach (CAFA). Finite element analyses have been performed on local damage area in spite of the whole large structure and transfer function based analytical model is used to analyze the full structure. "Scattered cube" of complex valued wave damage interaction coefficient (WDIC) that involves scattering and mode conversion of Lamb waves around the damage is used as coupling between analytical and FEM simulation. WDIC is captured for multiple angles of incident Lamb mode (S0 and A0) over the frequency domain to analyze the cracks of multiple-rivet-hole lap joint. By analyzing the scattered cube of WDICs over the frequency domain and azimuthal angles the optimum parameters can be determined for each angle of incidence and the most sensitive signals are obtained using WaveformRevealer2D (WFR2D). These sensitive signals confirm the detection of the butterfly cracks in rivet holes through the installment of the transmitting and sensing PWASs in the proper locations and selecting the right frequency of excitation.

  15. Statistical investigation of fatigue crack initiation and growth around chamfered rivet holes in Alclad 2024 T3 as affected by corrosion

    NASA Technical Reports Server (NTRS)

    Fadragas, M. I.; Fine, M. E.; Moran, B.

    1994-01-01

    In panel specimens with rivet holes cracks initiate in the blunted knife edge of the chamfered rivet hole and propagate inward as well as along the hole. The fatigue lifetime to dominant crack information was defined as the number of cycles, N500 micrometer, to formation of a 500 micrometer long crack. Statistical data on N500 micrometer and on crack propagation after N500 micrometer were obtained for a large number of uncorroded specimens and specimens corroded in an ASTM B 117 salt spray. Considerable variation in N500 micrometer and crack propagation behavior was observed from specimen to specimen of the same nominal geometry with chamfered rivet holes increased the probability for both early formation and later formation of a propagating 500 micrometer fatigue crack. The growth of fatigue cracks after 500 micrometer size was little affected by prior salt spray.

  16. Tank Tests of the Effect of Rivet Heads, etc., on the Water Performance of a Seaplane Float, Special Report

    NASA Technical Reports Server (NTRS)

    Parkinson, J. B.; Robertson, J. B., Jr.

    1936-01-01

    A 1/3.5 full-size model of the Mark V float of the Bureau of Aeronautics, Navy Department, was tested in the NACA tank both with smooth painted bottom surfaces and with roundhead rivets, plate laps, and keel plates fitted to simulate the actual bottom of a metal float. The augmentation in water resistance due to the added roughness was found to be from 10-12% at the hum speed and from 12-14% at high speeds. The effect of the roughness of the afterbody was found to be negligible except at high trims. The model data were extrapolated to full size by the usual method which assumes the forces to vary according to Froude's law, and in the case of the smooth model by a method of separation that takes into account the effect of scale on the frictional resistance. It was concluded that the effect of rivet heads on the takeoff performance of a relatively high-powered float seaplane is of little consequence but that it may be of greater importance in the case of more moderately powered flying boats.

  17. Tank Tests to Show the Effect Rivet Heads on the Water Performance of a Seaplane-Float

    NASA Technical Reports Server (NTRS)

    Parkinson, J B

    1938-01-01

    A 1/3.5 full-sized model of a seaplane float constructed from lines supplied by the Bureau of Aeronautics, Navy Department, was tested first with smooth painted bottom surfaces and then with round-head rivets, plate laps, and keel plates fitted to simulate the actual bottom of a metal float. A percentage increase in water resistance caused by the added roughness was found to be from 5 to 20 percent at the hump speed and from 15 to 40 percent at high speeds. The effect of the roughness of the afterbody was found to be negligible except at high trims. The model data were extrapolated to full size by the usual method that assumes the forces to vary according to Froude's law and, in the case of the smooth model, by a method of separation that takes into account the effect of scale on the frictional resistance. It was concluded that the effect of rivet heads on the take-off performance of a relatively high-powered float seaplane is of little consequence, but it may be of greater importance in the case of more moderately powered flying boats.

  18. Revisiting (Some of) the Lasting Impacts of the Liberty Ships via a Metallurgical Analysis of Rivets from the SS "John W. Brown"

    NASA Astrophysics Data System (ADS)

    Harris, M. D.; Grogg, W. J.; Akoma, A.; Hayes, B. J.; Reidy, R. F.; Imhoff, E. F.; Collins, P. C.

    2015-12-01

    During World War II, 2710 Liberty ships were built in the United States across 18 ship yards. The rate of production of these ships was at a scale not previously witnessed, reflecting a strategic marshaling of national assets critical to the war effort. For the metallurgist, metallurgical engineer, or materials scientist, these ships also struck commanding images regarding their catastrophic failures. The study of these failures led to increased understanding of brittle fracture, fracture mechanics, and ductile-to-brittle transition temperatures. The post-mortem studies of Liberty ships highlighted the importance of composition and microstructure in controlling the properties of steel in fracture-critical applications. This study examines a rivet from the SS "John W. Brown", which was assembled in Baltimore, Maryland, and launched in September 1942, The "John W. Brown" was restored between 1988 and 1991. Classical metallurgical analysis of a rivet from the original 1942 vessel is compared with modern rivets used during its restoration. The rivets provide an analogue to the plate material used in these ships. A comparison of these materials is presented along with a discussion of the importance of composition-microstructure-property relationships that concomitantly evolved.

  19. Type VII collagen associated with the basement membrane of amniotic epithelium forms giant anchoring rivets which penetrate a massive lamina reticularis.

    PubMed

    Ockleford, C D; McCracken, S A; Rimmington, L A; Hubbard, A R D; Bright, N A; Cockcroft, N; Jefferson, T B; Waldron, E; d'Lacey, C

    2013-09-01

    In human amnion a simple cuboidal epithelium and underlying fibroblast layer are separated by an almost acellular compact layer rich in collagen types I and III. This (>10 μm) layer, which may be a thick lamina reticularis, apparently presents an unusual set of conditions. Integration of the multilaminous tissue across it is apparently achieved by waisted structures which we have observed with the light microscope in frozen, paraffin-wax and semi-thin resin sections. We have also captured transmission and scanning electron micrographs of the structures. These structures which cross the compact layer we call "rivets". The composition of these "rivets" has been examined immunocytochemically and in three dimensions using the confocal laser scanning epi-fluorescence microscope. The rivets contain type VII collagen and an α6 integrin. They associate with type IV collagen containing structures (basement membrane lamina densa and spongy coils) and a special population of fibroblasts which may generate, maintain or anchor rivets to the underlying mesenchymal layer. Although type VII collagen is well known to anchor basal lamina to underlying mesodermal collagen fibres these "rivets" are an order of magnitude larger than any previously described type VII collagen containing anchoring structures. Intriguing possible functions of these features include nodes for growth of fibrous collagen sheets and sites of possible enzymatic degradation during regulated amnion weakening approaching term. If these sites are confirmed to be involved in amnion degradation and growth they may represent important targets for therapeutic agents that are designed to delay preterm premature rupture of the membranes a major cause of fetal morbidity and mortality.

  20. Lamb wave-based damage quantification and probability of detection modeling for fatigue life assessment of riveted lap joint

    NASA Astrophysics Data System (ADS)

    He, Jingjing; Wang, Dengjiang; Zhang, Weifang

    2015-03-01

    This study presents an experimental and modeling study for damage detection and quantification in riveted lap joints. Embedded lead zirconate titanate piezoelectric (PZT) ceramic wafer-type sensors are employed to perform in-situ non-destructive testing during fatigue cyclical loading. A multi-feature integration method is developed to quantify the crack size using signal features of correlation coefficient, amplitude change, and phase change. In addition, probability of detection (POD) model is constructed to quantify the reliability of the developed sizing method. Using the developed crack size quantification method and the resulting POD curve, probabilistic fatigue life prediction can be performed to provide comprehensive information for decision-making. The effectiveness of the overall methodology is demonstrated and validated using several aircraft lap joint specimens from different manufactures and under different loading conditions.

  1. A record of all marker bands found in the upper rivet rows of 2 adjacent bays from a fuselage lap splice joint

    NASA Technical Reports Server (NTRS)

    Willard, Scott A.

    1995-01-01

    A full scale fuselage test article was subjected to 60,000 load cycles (pressurizations) to study the effect of widespread fatigue damage in fuselage structures. Every 10,000 cycles coded marker block loading sequences were used to mark the fracture surfaces of the fatigue cracks propagating within the panel. The loading sequences consisted of series of underloads combined with a series of full pressurizations. The combination of loads and underloads marked the fracture surfaces with marker bands that could later be used to reconstruct the fatigue crack growth history of selected regions within the test article. Thirty rivet holes comprising the upper rivet rows from two adjacent bays (bays #3 and #4) from a fuselage lap splice joint were examined for the purpose of this study. Optical and scanning electron microscopy (SEM) were used to locate the marker bands.

  2. Compression Buckling Behavior of Large-Scale Friction Stir Welded and Riveted 2090-T83 Al-Li Alloy Skin-Stiffener Panels

    NASA Technical Reports Server (NTRS)

    Hoffman, Eric K.; Hafley, Robert A.; Wagner, John A.; Jegley, Dawn C.; Pecquet, Robert W.; Blum, Celia M.; Arbegast, William J.

    2002-01-01

    To evaluate the potential of friction stir welding (FSW) as a replacement for traditional rivet fastening for launch vehicle dry bay construction, a large-scale friction stir welded 2090-T83 aluminum-lithium (Al-Li) alloy skin-stiffener panel was designed and fabricated by Lockheed-Martin Space Systems Company - Michoud Operations (LMSS) as part of NASA Space Act Agreement (SAA) 446. The friction stir welded panel and a conventional riveted panel were tested to failure in compression at the NASA Langley Research Center (LaRC). The present paper describes the compression test results, stress analysis, and associated failure behavior of these panels. The test results provide useful data to support future optimization of FSW processes and structural design configurations for launch vehicle dry bay structures.

  3. Initiation and growth of multiple-site damage in the riveted lap joint of a curved stiffened fuselage panel: An experimental and analytical study

    NASA Astrophysics Data System (ADS)

    Ahmed, Abubaker Ali

    As part of the structural integrity research of the National Aging Aircraft Research Program, a comprehensive study on multiple-site damage (MSD) initiation and growth in a pristine lap-joint fuselage panel has been conducted. The curved stiffened fuselage panel was tested at the Full-Scale Aircraft Structural Test Evaluation and Research (FASTER) facility located at the Federal Aviation Administration William J. Hughes Technical Center. A strain survey test was conducted to verify proper load application. The panel was then subjected to a fatigue test with constant-amplitude cyclic loading. The applied loading spectrum included underload marker cycles so that crack growth history could be reconstructed from post-test fractographic examinations. Crack formation and growth were monitored via nondestructive and high-magnification visual inspections. Strain gage measurements recorded during the strain survey tests indicated that the inner surface of the skin along the upper rivet row of the lap joint experienced high tensile stresses due to local bending. During the fatigue loading, cracks were detected by eddy-current inspections at multiple rivet holes along the upper rivet row. Through-thickness cracks were detected visually after about 80% of the fatigue life. Once MSD cracks from two adjacent rivet holes linked up, there was a quick deterioration in the structural integrity of the lap joint. The linkup resulted in a 2.87" (72.9-mm) lead fatigue crack that rapidly propagated across 12 rivet holes and crossed over into the next skin bay, at which stage the fatigue test was terminated. A post-fatigue residual strength test was then conducted by loading the panel quasi-statically up to final failure. The panel failed catastrophically when the crack extended instantaneously across three additional bays. Post-test fractographic examinations of the fracture surfaces in the lap joint of the fuselage panel were conducted to characterize subsurface crack initiation and

  4. Development of new positive-selection RIVET tools: detection of induced promoters by the excision-based transcriptional activation of an aacCI (GmR)-gfp fusion.

    PubMed

    Lozano, M J; Salas, M E; Giusti, M A; Draghi, W O; Torres Tejerizo, G A; Martini, M C; Del Papa, M F; Pistorio, M; Lagares, A

    2011-09-10

    RIVET (Recombination Based in vivo Expression Technology) is a powerful genetic tool originally conceived for the identification of genes induced in complex biological niches where conventional transcriptomics is difficult to use. With a broader application, genetic recombination-based technologies have also been used, in combination with regulatory proteins and specific transcriptional regulators, for the development of highly sensitive biosensor systems. RIVET systems generally comprise two modules: a promoter-trap cassette generating genomic transcriptional fusions to the tnpR gene encoding the Tn-γδ TnpR resolvase, and a reporter cassette carrying res-flanked selection markers that are excised upon expression of tnpR to produce an irreversible, inheritable phenotypic change. We report here the construction and validation of a new set of positive-selection RIVET systems that, upon induction of the promoter-trap module, generate the transcriptional activation of an antibiotic-resistant and a green-fluorescent phenotype. Two classes of promoter-trap tools were constructed to generate transcriptional fusions to tnpR: one based on the use of a narrow-host-range plasmid (pRIVET-I), integrative in several Gram-negative bacteria, and the other based on the use of a broad-host-range plasmid (pRIVET-R). The system was evaluated in the model soil bacterium Sinorhizobium meliloti, where a clear-cut phenotypic transition from Nm(R)-Gm(S)-GFP(-) to Nm(S)-Gm(R)-GFP(+) occurred upon expression of tnpR. A S. meliloti integrative RIVET library was constructed in pRIVET-I and, as expected, changes in the extracellular conditions (e.g., salt stress) triggered a significant increase in the appearance of Gm(R)-GFP(+) (excised) clones. The sacB-independent positive-selection RIVET systems here described provide suitable basic tools both for the construction of new recombination-based biosensors and for the search of bacterial markers induced when microorganisms colonize and invade

  5. Asbestos fibres in the lungs of an American mechanic who drilled, riveted, and ground brake linings: a case report and discussion.

    PubMed

    Finkelstein, Murray M

    2015-05-01

    In North America and Europe, the use of asbestos in friction products was discontinued before the end of the 20th century. In the developing world, the use of asbestos-containing friction products continues. In 2010, Cely-Garcia and colleagues (Cely-Garcia et al., 2012) sampled three brake repair shops located in Bogota, Colombia. Both asbestos and non-asbestos containing brake linings were sold separately or attached to a shoe. When brake linings are sold separated from the shoe, they must be manipulated to attach them to the shoe before installation. The process starts with the removal of the old brake shoe from the vehicle's brake drum. If the existing brake shoe is to be reused, the old lining needs to be removed and the old shoe must be ground to prepare it for a new lining. Riveting requires drilling holes in the linings and shoes and before installing rivets, the lining must be countersunk. The borders of the lining are bevelled. On some occasions, the entire exposed surface of the lining is ground to make it thinner. Once attached to the shoe, the edges of brake linings may extend beyond the shoe. In this case, it is necessary to cut or grind the edges to match the lining to the shoe before bevelling or grinding. The authors reported that 'the sampling results indicate that the brake mechanics sampled are exposed to extremely high asbestos concentrations (i.e. based on transmission electron microscopy counts), suggesting that this occupational group could be at excess risk of asbestos-related diseases'. PMID:25842376

  6. Correction: Cecotti, H. and Rivet, B. Subject Combination and Electrode Selection in Cooperative Brain-Computer Interface Based on Event Related Potentials. Brain Sci. 2014, 4, 335–355

    PubMed Central

    Cecotti, Hubert; Rivet, Bertrand

    2014-01-01

    The authors wish to make the following correction to this paper (Cecotti, H.; Rivet, B. Subject Combination and Electrode Selection in Cooperative Brain-Computer Interface Based on Event Related Potentials. Brain Sci. 2014, 4, 335–355): Due to an internal error, the reference numbers in the original published paper were not shown, and the error was not due to the authors. The former main text should be replaced as below. PMID:25243772

  7. Fatigue Strength and Related Characteristics of Aircraft Joints I : Comparison of Spot-Weld and Rivet Patterns in 24s-t Alclad and 75s-t Alclad

    NASA Technical Reports Server (NTRS)

    Russell, H W; Jackson, L R; Grover, H J; Beaver, W W

    1944-01-01

    Report contains detailed results of a number of fatigue tests on spot-welded joints in aluminum alloys. The tests described include: (1) fatigue tests on spot-welded lap joints in sheets of unequal thickness of alclad 24s-t. These tests indicate that the fatigue strength of a spot-welded joint in sheets of two different gages is slightly higher than that of a similar joint in two sheets of the thinner gage but definitely lower than that of a similar joint in two sheets of the thicker gage. (2) Fatigue tests on spot-welded alclad 75s-t spot-welded lap-joint specimens of alclad 75s-t were not any stronger in fatigue than similar specimens of alclad 24s-t. (3) Fatigue tests on lap-joint specimens spot -welded after various surface preparations--these included ac welding wire-brushed surfaces, dc welding wire-brushed surfaces, and dc welding chemically cleaned surfaces. While the ac welds were strongest statically, the dc welds on wire-brushed surfaces were strongest in fatigue. Specimens prepared in this way were very nearly as strong as the best riveted specimens tested for comparison. (4) Fatigue tests on specimens spot-welded with varying voltage so as to include a wide range of static spot-weld strengths. The fatigue strengths were in the same order as the static strengths but showed less range. (author)

  8. The New Workforce: Not Just Rosie the Riveter.

    ERIC Educational Resources Information Center

    Sullivan, Leila Gonzalez

    American women have always been an integral part of the work force, first on the family farm and later as industrial laborers. In World War II, millions of women went to work only to be sent back home when the men returned. Today, women are in a very different situation. Between 1985 and 2000, 80% of new entrants into the work force are expected…

  9. Close Encounters with Deadly Dangers: Riveting Reads and Classroom Ideas.

    ERIC Educational Resources Information Center

    Haven, Kendall

    This book presents 15 tales that bring the animal world into the classroom. The stories in this book are divided into two sections: stories from aquatic ecosystems (both fresh- and saltwater systems), and from terrestrial systems, including desert, meadow, woodland, mountain, Arctic tundra, savanna, pine forest, and jungle ecosystems. All predator…

  10. RIVETS: A Mechanical System for In Vivo and In Vitro Electrophysiology and Imaging

    PubMed Central

    Osborne, Jason E.; Dudman, Joshua T.

    2014-01-01

    A number of recent studies have provided compelling demonstrations that both mice and rats can be trained to perform a variety of behavioral tasks while restrained by mechanical elements mounted to the skull. The independent development of this technique by a number of laboratories has led to diverse solutions. We found that these solutions often used expensive materials and impeded future development and modification in the absence of engineering support. In order to address these issues, here we report on the development of a flexible single hardware design for electrophysiology and imaging both in brain tissue in vitro. Our hardware facilitates the rapid conversion of a single preparation between physiology and imaging system and the conversion of a given system between preparations. In addition, our use of rapid prototyping machines (“3D printers”) allows for the deployment of new designs within a day. Here, we present specifications for design and manufacturing as well as some data from our lab demonstrating the suitability of the design for physiology in behaving animals and imaging in vitro and in vivo. PMID:24551206

  11. Investigation of pulsed eddy current probes for detection of defects in riveted structures

    NASA Astrophysics Data System (ADS)

    Yang, Binfeng; Zhang, Hui; Kang, Zhibin; Wang, Xiaofeng

    2013-09-01

    The fatigue crack is the threat to integrity and safety of fuselage lap-joints. Quantification of fatigue cracks by designing and utilisation of an optimised electromagnetic nondestructive evaluation probe can insure the flight safety of aircrafts. In this paper, pulsed eddy current (PEC) for detection and characterisation of fatigue cracks is investigated. The principle of PEC is analysed first, from which four different models of PEC probes are simulated in ANSYS. The signal features, namely zero-crossing time, zero-crossing frequency and peak value are extracted from the time and frequency domains in an effort to qualitatively compare the crack detectability of the four models. The sensitivities of the different probes to cracks are analysed quantitatively. The difference in detectability among the probes is investigated based on the working principle. Simulation results show that the probe consisting of two horizontal detecting coils along with a magnetic field shield focusing the flux has the highest detectability. The conclusions derived from the simulation study are also validated by experiments.

  12. Aircraft Assembly, Riveting and Surface Repair 2; Sheet Metal Work 2: 9855.03.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    This course provides experience in assembly techniques, including repairs on aircraft structures, utilizing all methods from basic layout to surface protection of finished parts. Course content includes goals, specific objectives, metal fasteners, general structural repairs, and aircraft assembly. A bibliography and post-test are appended. Prior…

  13. VIEW SOUTH FROM WITHING THE FORWARD (BOW) SECTION Rosie ...

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

    VIEW SOUTH FROM WITHING THE FORWARD (BOW) SECTION - Rosie the Riveter National Historical Park, Rosie the Riveter Memorial, Off Regatta at Melville Square in Marina Park, Richmond, Contra Costa County, CA

  14. VIEW EAST SHOWING THE WEST SIDE OF THE FORWARD (BOW) ...

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

    VIEW EAST SHOWING THE WEST SIDE OF THE FORWARD (BOW) SECTION - Rosie the Riveter National Historical Park, Rosie the Riveter Memorial, Off Regatta at Melville Square in Marina Park, Richmond, Contra Costa County, CA

  15. VIEW SOUTH SHOWING THE STRUCTURE REPRESENTING THE FORWARD (BOW) SECTION ...

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

    VIEW SOUTH SHOWING THE STRUCTURE REPRESENTING THE FORWARD (BOW) SECTION OF A LIBERTY SHIP - Rosie the Riveter National Historical Park, Rosie the Riveter Memorial, Off Regatta at Melville Square in Marina Park, Richmond, Contra Costa County, CA

  16. 46 CFR 160.043-3 - Materials.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... shall be 18 percent nickel-silver. (d) Handles. The handles shall be good quality, thermosetting, high impact plastic. (e) Rivets and pins. The rivets and pins shall be either hard brass or 18 percent...

  17. 46 CFR 160.043-3 - Materials.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... shall be 18 percent nickel-silver. (d) Handles. The handles shall be good quality, thermosetting, high impact plastic. (e) Rivets and pins. The rivets and pins shall be either hard brass or 18 percent...

  18. Classification of Magneto-Optic Images using Neural Networks

    NASA Technical Reports Server (NTRS)

    Nath, Shridhar; Wincheski, Buzz; Fulton, Jim; Namkung, Min

    1994-01-01

    A real time imaging system with a neural network classifier has been incorporated on a Macintosh computer in conjunction with an MOI system. This system images rivets on aircraft aluminium structures using eddy currents and magnetic imaging. Moment invariant functions from the image of a rivet is used to train a multilayer perceptron neural network to classify the rivets as good or bad (rivets with cracks).

  19. 75 FR 15629 - Airworthiness Directives; Cessna Aircraft Company Model 525A Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-30

    ... issued AD 2009-24-13, Cessna has developed new design thrust attenuator paddles and universal head rivets... fasteners with new design thrust attenuator paddles and universal head rivets. We are proposing this AD to... 2009-24-13, Cessna has developed new design thrust attenuator paddles and universal head rivets...

  20. 75 FR 34354 - Airworthiness Directives; Cessna Aircraft Company Model 525A Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-17

    ...-24-13, Cessna has developed new design thrust attenuator paddles and universal head rivets as... new design thrust attenuator paddles and universal head ] rivets. We are issuing this AD to detect and... with new design thrust attenuator paddles and universal head rivets: Total cost per Total cost on...

  1. 46 CFR 35.01-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., repairs, or other such operations involving riveting, welding, burning, or like fire-producing actions-TB... making alterations, repairs, or other such operations involving riveting, welding, burning, or like fire... with safety, no alterations, repairs, or other such operations involving riveting, welding, burning,...

  2. 46 CFR 71.60-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., repairs, or other such operations involving riveting, welding, burning or like fire-producing actions. 71... required when making alterations, repairs, or other such operations involving riveting, welding, burning or... undertaken with safety, no alterations, repairs, or other such operations involving riveting,...

  3. 46 CFR 35.01-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., repairs, or other such operations involving riveting, welding, burning, or like fire-producing actions-TB... making alterations, repairs, or other such operations involving riveting, welding, burning, or like fire... with safety, no alterations, repairs, or other such operations involving riveting, welding, burning,...

  4. 46 CFR 35.01-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., repairs, or other such operations involving riveting, welding, burning, or like fire-producing actions-TB..., repairs, or other such operations involving riveting, welding, burning, or like fire-producing actions—TB... safety, no alterations, repairs, or other such operations involving riveting, welding, burning, or...

  5. 46 CFR 71.60-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., repairs, or other such operations involving riveting, welding, burning or like fire-producing actions. 71... required when making alterations, repairs, or other such operations involving riveting, welding, burning or... undertaken with safety, no alterations, repairs, or other such operations involving riveting,...

  6. 46 CFR 71.60-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., repairs, or other such operations involving riveting, welding, burning or like fire-producing actions. 71... required when making alterations, repairs, or other such operations involving riveting, welding, burning or... undertaken with safety, no alterations, repairs, or other such operations involving riveting,...

  7. 46 CFR 71.60-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., repairs, or other such operations involving riveting, welding, burning or like fire-producing actions. 71... required when making alterations, repairs, or other such operations involving riveting, welding, burning or... undertaken with safety, no alterations, repairs, or other such operations involving riveting,...

  8. 46 CFR 71.60-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., repairs, or other such operations involving riveting, welding, burning or like fire-producing actions. 71... required when making alterations, repairs, or other such operations involving riveting, welding, burning or... undertaken with safety, no alterations, repairs, or other such operations involving riveting,...

  9. 46 CFR 35.01-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., repairs, or other such operations involving riveting, welding, burning, or like fire-producing actions-TB..., repairs, or other such operations involving riveting, welding, burning, or like fire-producing actions—TB... safety, no alterations, repairs, or other such operations involving riveting, welding, burning, or...

  10. 46 CFR 35.01-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., repairs, or other such operations involving riveting, welding, burning, or like fire-producing actions-TB... making alterations, repairs, or other such operations involving riveting, welding, burning, or like fire... with safety, no alterations, repairs, or other such operations involving riveting, welding, burning,...

  11. Summary of Results of Tests Made by Aluminum Research Laboratories of Spot-welded Joints and Structural Elements

    NASA Technical Reports Server (NTRS)

    HARTMANN E C; Stickley, G W

    1942-01-01

    Available information concerning spot welding as a means of joining aluminum-alloy parts has been summarized and comparisons have been made of the relative merits of spot-welded and riveted aluminum-alloy structural elements. The results indicated that spot welding was as satisfactory as riveting insofar as resistance to static loads is concerned. Spot welds showed slightly lower resistance to impact loads but definitely lower resistance to repeated loads than rivets.

  12. VIEW NORTH FROM THE AFT (FANTAIL) SECTION OF THE MEMORIAL, ...

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

    VIEW NORTH FROM THE AFT (FANTAIL) SECTION OF THE MEMORIAL, LOOKING FORWARD TOWARD THE STACK AND BOW SECTIONS - Rosie the Riveter National Historical Park, Rosie the Riveter Memorial, Off Regatta at Melville Square in Marina Park, Richmond, Contra Costa County, CA

  13. 75 FR 64111 - Airworthiness Directives; Cessna Aircraft Company (Cessna) Models 336, 337, 337A (USAF 02B), 337B...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-19

    ... STC SA02055AT. The damage was described as starting with loose and working (smoking) rivets in the... station (WSTA) 150. The cracks were on both wings of the airplane and covered by repair patches. The wing... loose and working (smoking) rivets in the upper surface of the wing, buckling of the upper surface...

  14. 77 FR 60655 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-04

    ... observed on both sides of the keel beam around the rivets below the center wing box between frame (FR) 40... the center wing box and corrective actions , depending on findings. You may obtain further information... rivets on both sides of the keel beam side panel below the center wing box at STGR 42 on the LH and...

  15. 46 CFR 91.50-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., repairs, or other such operations involving riveting, welding, burning or like fire-producing actions. 91... testing required when making alterations, repairs, or other such operations involving riveting, welding..., welding, burning, or like fire-producing actions shall be made: (1) Within or on the boundaries of...

  16. 46 CFR 91.50-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., repairs, or other such operations involving riveting, welding, burning or like fire-producing actions. 91... testing required when making alterations, repairs, or other such operations involving riveting, welding..., welding, burning, or like fire-producing actions shall be made: (1) Within or on the boundaries of...

  17. 46 CFR 91.50-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., repairs, or other such operations involving riveting, welding, burning or like fire-producing actions. 91... testing required when making alterations, repairs, or other such operations involving riveting, welding..., welding, burning, or like fire-producing actions shall be made: (1) Within or on the boundaries of...

  18. 46 CFR 91.50-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., repairs, or other such operations involving riveting, welding, burning or like fire-producing actions. 91... testing required when making alterations, repairs, or other such operations involving riveting, welding..., welding, burning, or like fire-producing actions shall be made: (1) Within or on the boundaries of...

  19. 46 CFR 91.50-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., repairs, or other such operations involving riveting, welding, burning or like fire-producing actions. 91... testing required when making alterations, repairs, or other such operations involving riveting, welding..., welding, burning, or like fire-producing actions shall be made: (1) Within or on the boundaries of...

  20. 49 CFR 179.201-3 - Lined tanks.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... sump is permitted. No lining must be under tension when applied except due to conformation over rivet... surface of heads must be driven tight against the plate. All plates, castings and rivet heads on the... from porosity. (d) All surfaces of attachments or fittings and their closures exposed to the...

  1. 49 CFR 179.201-3 - Lined tanks.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... sump is permitted. No lining must be under tension when applied except due to conformation over rivet... surface of heads must be driven tight against the plate. All plates, castings and rivet heads on the... from porosity. (d) All surfaces of attachments or fittings and their closures exposed to the...

  2. 49 CFR 179.201-3 - Lined tanks.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... sump is permitted. No lining must be under tension when applied except due to conformation over rivet... surface of heads must be driven tight against the plate. All plates, castings and rivet heads on the... from porosity. (d) All surfaces of attachments or fittings and their closures exposed to the...

  3. 49 CFR 179.201-3 - Lined tanks.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... sump is permitted. No lining must be under tension when applied except due to conformation over rivet... surface of heads must be driven tight against the plate. All plates, castings and rivet heads on the... from porosity. (d) All surfaces of attachments or fittings and their closures exposed to the...

  4. 9. VIEW TO SOUTHEAST ALONG THE LENGTH OF THE SOUTHWEST ...

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

    9. VIEW TO SOUTHEAST ALONG THE LENGTH OF THE SOUTHWEST SIDE BAY. NOTE WORK AREAS IN LEAN-TO BAYS ALONG RIGHT SIDE. - Rosie the Riveter National Historical Park, Auxiliary Plate Shop, 912 Harbour Way, Richmond, Contra Costa County, CA

  5. 14. VIEW TO SOUTHWEST AT NORTH END OF SECONDFLOOR ASSEMBLY ...

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

    14. VIEW TO SOUTHWEST AT NORTH END OF SECOND-FLOOR ASSEMBLY AREA. VIEW SHOWS DETAILS OF SAWTOOTH ROOF STRUCTURE. - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  6. 4. VIEW TO EAST SHOWING WEST END OF CRANEWAY (CENTER), ...

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

    4. VIEW TO EAST SHOWING WEST END OF CRANEWAY (CENTER), WEST SIDE OF ASSEMBLY BUILDING (LEFT), AND WHARF (RIGHT). - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  7. 7. GENERAL WAREHOUSE, PERSPECTIVE VIEW TO NORTHWEST SHOWING FRONT ELEVATION ...

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

    7. GENERAL WAREHOUSE, PERSPECTIVE VIEW TO NORTHWEST SHOWING FRONT ELEVATION (LEFT) AND NORTH SIDE (RIGHT). - Rosie the Riveter National Historical Park, General Warehouse, 1320 Canal Boulevard, Richmond, Contra Costa County, CA

  8. 5. GENERAL WAREHOUSE, PERSPECTIVE VIEW TO NORTHWEST SHOWING FRONT ELEVATION ...

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

    5. GENERAL WAREHOUSE, PERSPECTIVE VIEW TO NORTHWEST SHOWING FRONT ELEVATION (LEFT) AND NORTH SIDE (RIGHT). - Rosie the Riveter National Historical Park, General Warehouse, 1320 Canal Boulevard, Richmond, Contra Costa County, CA

  9. 13. VIEW TO SOUTHEAST OF WAITING AREA SHOWING STAIRS TO ...

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

    13. VIEW TO SOUTHEAST OF WAITING AREA SHOWING STAIRS TO FIRST FLOOR (LEFT) AND HALL TO MANAGERS OFFICES (RIGHT). - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  10. CAFETERIA AT SHIPYARD NO. 3, PERSPECTIVE VIEW TO NORTHWEST SHOWING ...

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

    CAFETERIA AT SHIPYARD NO. 3, PERSPECTIVE VIEW TO NORTHWEST SHOWING SOUTHEAST END AND FRONT SIDE (SHADED BY TREES) - Rosie the Riveter National Historical Park, Cafeteria, 1301 Canal Boulevard, Richmond, Contra Costa County, CA

  11. 7. VIEW TO EAST SHOWING ELEVATION OF THE OFFICE PORTION ...

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

    7. VIEW TO EAST SHOWING ELEVATION OF THE OFFICE PORTION OF THE STRUCTURE AT NORTHWEST CORNER. - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  12. 3. VIEW TO WEST SHOWING EAST END OF OIL HOUSE ...

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

    3. VIEW TO WEST SHOWING EAST END OF OIL HOUSE (LEFT) AND EAST SIDE OF CRATING SHED AND ASSEMBLY BUILDING (RIGHT BACKGROUND). - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  13. 4. GENERAL WAREHOUSE, PERSPECTIVE VIEW TO NORTHWEST SHOWING SOUTH SIDE ...

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

    4. GENERAL WAREHOUSE, PERSPECTIVE VIEW TO NORTHWEST SHOWING SOUTH SIDE (LEFT) AND FRONT ELEVATION (RIGHT). - Rosie the Riveter National Historical Park, General Warehouse, 1320 Canal Boulevard, Richmond, Contra Costa County, CA

  14. 2. VIEW TO SOUTHWEST SHOWING OIL HOUSE (LEFT), BOILER ROOM ...

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

    2. VIEW TO SOUTHWEST SHOWING OIL HOUSE (LEFT), BOILER ROOM AND STACK (CENTER), ROOF OF CRANEWAY (BACKGROUND), AND CRATING SHED (RIGHT). - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  15. 1. VIEW TO NORTHEAST ACROSS RICHMOND INNER HARBOR FROM RICHMOND ...

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

    1. VIEW TO NORTHEAST ACROSS RICHMOND INNER HARBOR FROM RICHMOND SHIPYARD NO. 3. - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  16. 3. VIEW TO WEST SHOWING NORTHEAST SIDE OF BUILDING. NOTE ...

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

    3. VIEW TO WEST SHOWING NORTHEAST SIDE OF BUILDING. NOTE STIFFENING TRUSS OVER DOORWAY TO SUPPORT THE WALL. - Rosie the Riveter National Historical Park, Auxiliary Plate Shop, 912 Harbour Way, Richmond, Contra Costa County, CA

  17. 6. GENERAL WAREHOUSE, VIEW TO EAST SHOWING DETAIL OF ELEVATOR ...

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

    6. GENERAL WAREHOUSE, VIEW TO EAST SHOWING DETAIL OF ELEVATOR DOOR (CENTER), FLANKING PEDESTRIAN ENTRIES, AND LOADING DOCK. - Rosie the Riveter National Historical Park, General Warehouse, 1320 Canal Boulevard, Richmond, Contra Costa County, CA

  18. 1. PERSPECTIVE VIEW TO WEST SHOWING SOUTHEAST END. NOTE THAT ...

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

    1. PERSPECTIVE VIEW TO WEST SHOWING SOUTHEAST END. NOTE THAT EXTERIOR CRANEWAY TRESTLES HAVE BEEN REDUCED IN LENGTH. - Rosie the Riveter National Historical Park, Auxiliary Plate Shop, 912 Harbour Way, Richmond, Contra Costa County, CA

  19. 7. VIEW TO NORTHEAST AT NORTHWEST END OF BUILDING. NOTE ...

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

    7. VIEW TO NORTHEAST AT NORTHWEST END OF BUILDING. NOTE CRANEWAY TRESTLE EXTENDING BEYOND END OF BUILDING. - Rosie the Riveter National Historical Park, Auxiliary Plate Shop, 912 Harbour Way, Richmond, Contra Costa County, CA

  20. 6. NORTH END OF MACHINE SHOP. FORGE SHOP (HAER No. ...

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

    6. NORTH END OF MACHINE SHOP. FORGE SHOP (HAER No. CA-326-K) ON LEFT, FORD PLANT IN DISTANCE, NE BY 60. - Rosie the Riveter National Historical Park, Machine Shop, 1311 Canal Boulevard, Richmond, Contra Costa County, CA

  1. FROM LEFT TO RIGHT, 115, 117, 119, 121, 123, 125, ...

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

    FROM LEFT TO RIGHT, 115, 117, 119, 121, 123, 125, 127, 129 COLLINS STREET. ATCHISON VILLAGE HOUSED WORKERS DURING WORLD WAR II - Rosie the Riveter National Historical Park, Atchison Village, Collins Street, Richmond, Contra Costa County, CA

  2. 40 CFR 205.158 - Labeling requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... distributed in commerce. (2) The label must be plastic or metal and be welded, riveted, or otherwise... manufacturer begins production of vehicles subject to this regulation, the Administrator will assign him a...

  3. 12. DETAIL OF CONNECTION BETWEEN SOUTHEAST END POST AND TOP ...

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

    12. DETAIL OF CONNECTION BETWEEN SOUTHEAST END POST AND TOP CHORD, SHOWING BOLT, RIVETED PLATES, AND EYE BAR; VIEW FROM WEST. - Mitchell's Mill Bridge, Spanning Winter's Run on Carrs Mill Road, west of Bel Air, Bel Air, Harford County, MD

  4. 17. MARINA WAY, HARBOUR WAY, AND MARITIME CHILD DEVELOPMENT CENTER ...

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

    17. MARINA WAY, HARBOUR WAY, AND MARITIME CHILD DEVELOPMENT CENTER (SEE ALSO HABS No. CA-2718), WITH RICHMOND SHIPYARD NO. 3. S. - Rosie the Riveter National Historical Park, 1401 Marina Way South, Richmond, Contra Costa County, CA

  5. 9. DETAIL SHOWING VERTICAL AND DIAGONAL WEB MEMBERS OF A ...

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

    9. DETAIL SHOWING VERTICAL AND DIAGONAL WEB MEMBERS OF A TRUSS RIVETED TOGETHER AT THE TOPCHORD OF THE EAST ELEVATION, LOOKING EAST - Wilson Mill Bridge, Spanning Deer Creek at MD Route 161, Darlington, Harford County, MD

  6. 3. GENERAL VIEW OF BOILER ROOM, LOOKING NORTH; CONTROL PANEL ...

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

    3. GENERAL VIEW OF BOILER ROOM, LOOKING NORTH; CONTROL PANEL AT CENTER; BOXLIKE, RIVETED HOUSING AT TOP CENTER CONTAINED AUGER FOR COAL DISTRIBUTION SYSTEM - Rath Packing Company, Boiler Room, Sycamore Street between Elm & Eighteenth Streets, Waterloo, Black Hawk County, IA

  7. 14 CFR Appendix C to Part 147 - Airframe Curriculum Subjects

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... conventional rivets. (3) 16. Form, lay out, and bend sheet metal. e. welding (1) 17. Weld magnesium and...-weld, and arc-weld steel. (1) 21. Weld aluminum and stainless steel. f. assembly and rigging (1)...

  8. PANORAMIC VIEW OF SHIPYARD NO. 3, LOOKING SOUTHEAST. FIRST AID ...

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

    PANORAMIC VIEW OF SHIPYARD NO. 3, LOOKING SOUTHEAST. FIRST AID STATION AT CENTER LEFT AND FORGE SHOP AT RIGHT - Rosie the Riveter National Historical Park, Richmond Shipyard No. 3, Point Potrero, Richmond, Contra Costa County, CA

  9. Evaluation of the fuselage lap joint fatigue and terminating action repair

    NASA Technical Reports Server (NTRS)

    Samavedam, Gopal; Thomson, Douglas; Jeong, David Y.

    1994-01-01

    Terminating action is a remedial repair which entails the replacement of shear head countersunk rivets with universal head rivets which have a larger shank diameter. The procedure was developed to eliminate the risk of widespread fatigue damage (WFD) in the upper rivet row of a fuselage lap joint. A test and evaluation program has been conducted by Foster-Miller, Inc. (FMI) to evaluate the terminating action repair of the upper rivet row of a commercial aircraft fuselage lap splice. Two full scale fatigue tests were conducted on fuselage panels using the growth of fatigue cracks in the lap joint. The second test was performed to evaluate the effectiveness of the terminating action repair. In both tests, cyclic pressurization loading was applied to the panels while crack propagation was recorded at all rivet locations at regular intervals to generate detailed data on conditions of fatigue crack initiation, ligament link-up, and fuselage fracture. This program demonstrated that the terminating action repair substantially increases the fatigue life of a fuselage panel structure and effectively eliminates the occurrence of cracking in the upper rivet row of the lap joint. While high cycle crack growth was recorded in the middle rivet row during the second test, failure was not imminent when the test was terminated after cycling to well beyond the service life. The program also demonstrated that the initiation, propagation, and linkup of WFD in full-scale fuselage structures can be simulated and quantitatively studied in the laboratory. This paper presents an overview of the testing program and provides a detailed discussion of the data analysis and results. Crack distribution and propagation rates and directions as well as frequency of cracking are presented for both tests. The progression of damage to linkup of adjacent cracks and to eventual overall panel failure is discussed. In addition, an assessment of the effectiveness of the terminating action repair and the

  10. Fracture analysis of multi-site cracking in fuselage lap joints

    NASA Astrophysics Data System (ADS)

    Beuth, J. L.; Hutchinson, J. W.

    1994-09-01

    A two-dimensional plane stress elastic fracture mechanics analysis of a cracked lap joint fastened by rigid pins is presented and results are applied to the problem of multi-site damage (MSD) in riveted lap joints of aircraft fuselage skins. Two problems are addressed, the problem of equal length MSD cracks and the problem of alternating length MSD cracks. For the problem of equal length cracks, two models of rivet/skin interactions are studied and the role of residual stresses due to the riveting process is explored. Stress intensity factors are obtained as a function of normalized crack length. Also, the load distribution among rivet rows and the compliance change of the joint due to MSD cracking are obtained. For the problem of alternating length cracks, attention is focussed on how load is distributed between columns of rivets and how this load shedding can alter crack tip stress intensity factors. The equal and alternating length crack analyses reveal no clear-cut mechanism to explain the relative uniformity of fatigue cracks emerging from lap joint rivet holes in actual aircraft and in mechanical lap joint tests.

  11. Fatigue strength of a single lap joint SPR-bonded

    SciTech Connect

    Di Franco, G.; Fratini, L.; Pasta, A.

    2011-05-04

    In the last years, hybrid joints, meaning with this the joints which consist in combining a traditional mechanical joint to a layer of adhesive, are gradually attracting the attention of various sectors of the construction of vehicles and transportation industries, for their better performance compared to just mechanical joints (self-piercing riveting SPR, riveting, and so on) or just to bonded joints.The paper investigates the fatigue behavior of a single lap joint self-piercing riveted (SPR) and bonded throughout fatigue tests. The considered geometric configuration allowed the use of two rivets placed longitudinally; an epoxy resin was used as adhesive. In the first part of the work static characterization of the joints was carried out through tensile tests. Then fatigue tests were made with the application of different levels of load. The fatigue curves were also obtained at the varying the distance between the two rivets in order to better assess the joint strength for a given length of overlap.

  12. Automatic Fastening Large Structures: a New Approach

    NASA Technical Reports Server (NTRS)

    Lumley, D. F.

    1985-01-01

    The external tank (ET) intertank structure for the space shuttle, a 27.5 ft diameter 22.5 ft long externally stiffened mechanically fastened skin-stringer-frame structure, was a labor intensitive manual structure built on a modified Saturn tooling position. A new approach was developed based on half-section subassemblies. The heart of this manufacturing approach will be 33 ft high vertical automatic riveting system with a 28 ft rotary positioner coming on-line in mid 1985. The Automatic Riveting System incorporates many of the latest automatic riveting technologies. Key features include: vertical columns with two sets of independently operating CNC drill-riveting heads; capability of drill, insert and upset any one piece fastener up to 3/8 inch diameter including slugs without displacing the workpiece offset bucking ram with programmable rotation and deep retraction; vision system for automatic parts program re-synchronization and part edge margin control; and an automatic rivet selection/handling system.

  13. Development of ultrafine-grained microstructure in Al-Cu-Mg alloy through equal-channel angular pressing

    NASA Astrophysics Data System (ADS)

    Sai Anuhya, Danam; Gupta, Ashutosh; Nayan, Niraj; Narayana Murty, S. V. S.; Manna, R.; Sastry, G. V. S.

    2014-08-01

    Al-Cu-Mg alloys are extensively used for riveting applications in aerospace industries due to their relatively high shear strength coupled with high plasticity. The significant advantage of using V65 aluminum alloy ((Al-4Cu-0.2Mg) for rivet application also stems from its significantly slower natural aging kinetics, which gives operational flexibility to carryout riveting operation even after 4 days of solution heat treatment, in contrast to its equivalent alloy AA2024.Rivets are usually made by cold heading of wire rods. In order to form a defect free rivet head, grain size control in wire rods is essential at each and every stage of processing right from casting onwards upto the final wire drawing stage. Wire drawing is carried out at room temperature to reduce diameter as well as impart good surface finish. In the present study, different microstructures in V65 alloy bars were produced by rolling at different temperatures (room temperature to 523K) and subsequently deformed by equal channel angular pressing (ECAP) at 423K upto an equivalent strain of 7. ECAP was carried out to study the effect of initial microstructure on grain refinement and degree of deformation on the evolution of ultrafine grain structure. The refinement of V65 alloy by ECAP is significantly influenced by Initial microstructure but amount of deformation strongly affects the evolution processes as revealed by optical microscopy and transmission electron microscopy.

  14. Rotating flux-focusing eddy current probe for flaw detection

    NASA Technical Reports Server (NTRS)

    Wincheski, Russell A. (Inventor); Fulton, James P. (Inventor); Nath, Shridhar C. (Inventor); Simpson, John W. (Inventor); Namkung, Min (Inventor)

    1997-01-01

    A flux-focusing electromagnetic sensor which uses a ferromagnetic flux-focusing lens simplifies inspections and increases detectability of fatigue cracks about circular fasteners and other circular inhomogeneities in high conductivity material. The unique feature of the device is the ferrous shield isolating a high-turn pick-up coil from an excitation coil, The use of the magnetic shield is shown to produce a null voltage output across the receiving coil in the presence of an unflawed sample. A redistribution of the current flow in the sample caused by the presence of flaws, however, eliminates the shielding condition and a large output voltage is produced, yielding a clear unambiguous flaw signal. By rotating the probe in a path around a circular fastener such as a rivet while maintaining a constant distance between the probe and the center of a rivet, the signal due to current flow about the rivet can be held constant. Any further changes in the current distribution, such as due to a fatigue crack at the rivet joint, can be detected as an increase in the output voltage above that due to the flow about the rivet head.

  15. The Effects of Some Surface Irregularities on Wing Drag

    NASA Technical Reports Server (NTRS)

    Drag, Manley

    1939-01-01

    The N.A.C.A. has conducted tests to provide more complete data than were previously available for estimating the effects of common surface irregularities on wing drag. The irregularities investigated included: brazier-head and countersunk rivets, spot welds, several types of sheet-metal joints, and surface roughness. Tests were also conducted to determine the over-all effect of manufacturing irregularities incidental to riveted aluminum alloy and to spot-welded stainless-steel construction. The tests were made in the 8-foot high speed wind tunnel at Reynolds Numbers up to 18,000,000. The results show that any of the surface irregularities investigated may increase wing drag enough to have important adverse effects on high-speed performance and economy. A method of estimating increases in wing drag caused by brazier-head rivets and lapped joints under conditions outside the range of the tests is suggested. Estimated drag increases due to rivets and lapped joints under conditions outside the range of the tests is suggested. Estimated drag increases due to rivets and lapped joints on a wing of 20-foot chord flying at 250 miles per hour are shown.

  16. Rotating concave eddy current probe

    DOEpatents

    Roach, Dennis P.; Walkington, Phil; Rackow, Kirk A.; Hohman, Ed

    2008-04-01

    A rotating concave eddy current probe for detecting fatigue cracks hidden from view underneath the head of a raised head fastener, such as a buttonhead-type rivet, used to join together structural skins, such as aluminum aircraft skins. The probe has a recessed concave dimple in its bottom surface that closely conforms to the shape of the raised head. The concave dimple holds the probe in good alignment on top of the rivet while the probe is rotated around the rivet's centerline. One or more magnetic coils are rigidly embedded within the probe's cylindrical body, which is made of a non-conducting material. This design overcomes the inspection impediment associated with widely varying conductivity in fastened joints.

  17. Preliminary results on the fracture analysis of multi-site cracking of lap joints in aircraft skins

    NASA Astrophysics Data System (ADS)

    Beuth, J. L., Jr.; Hutchinson, John W.

    1992-07-01

    Results of a fracture mechanics analysis relevant to fatigue crack growth at rivets in lap joints of aircraft skins are presented. Multi-site damage (MSD) is receiving increased attention within the context of problems of aging aircraft. Fracture analyses previously carried out include small-scale modeling of rivet/skin interactions, larger-scale two-dimensional models of lap joints similar to that developed here, and full scale three-dimensional models of large portions of the aircraft fuselage. Fatigue testing efforts have included flat coupon specimens, two-dimensional lap joint tests, and full scale tests on specimens designed to closely duplicate aircraft sections. Most of this work is documented in the proceedings of previous symposia on the aging aircraft problem. The effect MSD has on the ability of skin stiffeners to arrest the growth of long skin cracks is a particularly important topic that remains to be addressed. One of the most striking features of MSD observed in joints of some test sections and in the joints of some of the older aircraft fuselages is the relative uniformity of the fatigue cracks from rivet to rivet along an extended row of rivets. This regularity suggests that nucleation of the cracks must not be overly difficult. Moreover, it indicates that there is some mechanism which keeps longer cracks from running away from shorter ones, or, equivalently, a mechanism for shorter cracks to catch-up with longer cracks. This basic mechanism has not been identified, and one of the objectives of the work is to see to what extent the mechanism is revealed by a fracture analysis of the MSD cracks. Another related aim is to present accurate stress intensity factor variations with crack length which can be used to estimate fatigue crack growth lifetimes once cracks have been initiated. Results are presented which illustrate the influence of load shedding from rivets with long cracks to neighboring rivets with shorter cracks. Results are also included

  18. Preliminary results on the fracture analysis of multi-site cracking of lap joints in aircraft skins

    NASA Technical Reports Server (NTRS)

    Beuth, J. L., Jr.; Hutchinson, John W.

    1992-01-01

    Results of a fracture mechanics analysis relevant to fatigue crack growth at rivets in lap joints of aircraft skins are presented. Multi-site damage (MSD) is receiving increased attention within the context of problems of aging aircraft. Fracture analyses previously carried out include small-scale modeling of rivet/skin interactions, larger-scale two-dimensional models of lap joints similar to that developed here, and full scale three-dimensional models of large portions of the aircraft fuselage. Fatigue testing efforts have included flat coupon specimens, two-dimensional lap joint tests, and full scale tests on specimens designed to closely duplicate aircraft sections. Most of this work is documented in the proceedings of previous symposia on the aging aircraft problem. The effect MSD has on the ability of skin stiffeners to arrest the growth of long skin cracks is a particularly important topic that remains to be addressed. One of the most striking features of MSD observed in joints of some test sections and in the joints of some of the older aircraft fuselages is the relative uniformity of the fatigue cracks from rivet to rivet along an extended row of rivets. This regularity suggests that nucleation of the cracks must not be overly difficult. Moreover, it indicates that there is some mechanism which keeps longer cracks from running away from shorter ones, or, equivalently, a mechanism for shorter cracks to catch-up with longer cracks. This basic mechanism has not been identified, and one of the objectives of the work is to see to what extent the mechanism is revealed by a fracture analysis of the MSD cracks. Another related aim is to present accurate stress intensity factor variations with crack length which can be used to estimate fatigue crack growth lifetimes once cracks have been initiated. Results are presented which illustrate the influence of load shedding from rivets with long cracks to neighboring rivets with shorter cracks. Results are also included

  19. Three reading aids painted by Tomaso da Modena in the chapter house of San Nicolò Monastery in Treviso, Italy.

    PubMed

    Daxecker, F

    1999-01-01

    In 1352 the artist Tomaso da Modena depicted three monks with reading aids in the chapter house of San Nicolò Monastery. One of them is wearing rivet spectacles, the second is using a reading glass, and the third has a reading glass on a stand. These rivet spectacles are often quoted in the literature as the first pictorial representation of spectacles, while the reading glass was found in only one reference in the literature with only one illustration, and the reading glass with stand was not found at all.

  20. 2. GENERAL WAREHOUSE AT SHIPYARD NO. 3, PERSPECTIVE VIEW TO ...

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

    2. GENERAL WAREHOUSE AT SHIPYARD NO. 3, PERSPECTIVE VIEW TO WEST SOUTHWEST, OF FRONT ELEVATION AND NORTH SIDE. LOOKING ACROSS RICHMOND INNER HARBOR FROM NEAR THE FORD ASSEMBLY BUILDING. - Rosie the Riveter National Historical Park, General Warehouse, 1320 Canal Boulevard, Richmond, Contra Costa County, CA

  1. 1. VIEW OF GENERAL WAREHOUSE (LEFT) AND MACHINE SHOP (RIGHT) ...

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

    1. VIEW OF GENERAL WAREHOUSE (LEFT) AND MACHINE SHOP (RIGHT) AT SHIPYARD NO. 3, VIEW TO WEST-SOUTHWEST. LOOKING ACROSS RICHMOND INNER HARBOR FROM NEAR THE FORD ASSEMBLY BUILDING. - Rosie the Riveter National Historical Park, General Warehouse, 1320 Canal Boulevard, Richmond, Contra Costa County, CA

  2. 6. VIEW TO SOUTHEAST ALONG CENTRAL BAY. NOTE TRUSSED SUPPORT ...

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

    6. VIEW TO SOUTHEAST ALONG CENTRAL BAY. NOTE TRUSSED SUPPORT FOR CRANEWAY TRACKS WITH OVERHEAD BRIDGE CRANES IN BACKGROUND. NOTE ALSO SWINGING BOOM CRANES ATTACHED TO COLUMNS. - Rosie the Riveter National Historical Park, Auxiliary Plate Shop, 912 Harbour Way, Richmond, Contra Costa County, CA

  3. MACHINE SHOP AT SHIPYARD NO. 3, VIEW TO WESTSOUTHWEST OF ...

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

    MACHINE SHOP AT SHIPYARD NO. 3, VIEW TO WEST-SOUTHWEST OF THE EAST ELEVATION. LOOKING ACROSS THE RICHMOND INNER HARBOR FROM NEAR THE FORD ASSEMBLY BUILDING - Rosie the Riveter National Historical Park, Machine Shop, 1311 Canal Boulevard, Richmond, Contra Costa County, CA

  4. 8. VIEW TO EAST SHOWING PORTION OF WEST ELEVATION OF ...

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

    8. VIEW TO EAST SHOWING PORTION OF WEST ELEVATION OF ASSEMBLY AREA. MAIN ASSEMBLY LINE RAN FROM RIGHT TO LEFT ALONG THE FIRST-FLOOR WINDOWS. PARTS STORAGE WAS ON SECOND FLOOR. - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  5. 11. INTERIOR VIEW TO WEST ALONG SOUTHWEST SIDE OF BUILDING ...

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

    11. INTERIOR VIEW TO WEST ALONG SOUTHWEST SIDE OF BUILDING WITH NORTHWEST END OF BUILDING IN BACKGROUND. NOTE WORK AREAS IN LEAN-TO BAYS ALONG SIDE OF BUILDING. ALSO NOTE TRAVELING BRIDGE CRANES OVERHEAD AND SWINGING BOOM CRANES ATTACHED TO COLUMNS. - Rosie the Riveter National Historical Park, Auxiliary Plate Shop, 912 Harbour Way, Richmond, Contra Costa County, CA

  6. 9. VIEW TO SOUTH SHOWING ENTRANCES TO BUILDING AT NORTHEAST ...

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

    9. VIEW TO SOUTH SHOWING ENTRANCES TO BUILDING AT NORTHEAST CORNER. DOORS TO LEFT WERE FOR INTERIOR RAILROAD SPUR. ROLL-UP GARAGE DOOR TO RIGHT HAS REPLACED ORIGINAL PEDESTRIAN DOORS WHERE HOURLY SHIP WORKERS REPORTED TO WORK. - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  7. 8. VIEW TO SOUTHEAST FROM NORTHWEST END OF BUILDING, ELEVATION ...

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

    8. VIEW TO SOUTHEAST FROM NORTHWEST END OF BUILDING, ELEVATION OF CENTER BAY WOODEN PRATT ROOF TRUSSES. NOTE VARIABLE DIMENSIONS OF VERTICAL AND DIAGONAL MEMBERS: THICKER TOWARD ENDS AND THINNER TOWARD CENTER. - Rosie the Riveter National Historical Park, Auxiliary Plate Shop, 912 Harbour Way, Richmond, Contra Costa County, CA

  8. 6. PERSPECTIVE VIEW TO SOUTHWEST SHOWING NORTHWEST CORNER OF ASSEMBLY ...

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

    6. PERSPECTIVE VIEW TO SOUTHWEST SHOWING NORTHWEST CORNER OF ASSEMBLY BUILDING WHERE SHOWROOMS (FIRST FLOOR) AND OFFICES (SECOND FLOOR) WERE LOCATED. WEST SIDE OF ASSEMBLY AREA IS TO RIGHT. - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  9. MACHINE SHOP, PERSPECTIVE VIEW TO NORTHNORTHEAST OF THE WEST SIDE ...

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

    MACHINE SHOP, PERSPECTIVE VIEW TO NORTH-NORTHEAST OF THE WEST SIDE AND SOUTH END. WEST (REAR) SIDE OF GENERAL WAREHOUSE IS IN RIGHT FOREGROUND - Rosie the Riveter National Historical Park, Machine Shop, 1311 Canal Boulevard, Richmond, Contra Costa County, CA

  10. YARD NO. 3 BASINS (GRAVING DOCKS), VIEW TO EASTNORTHEAST AT ...

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

    YARD NO. 3 BASINS (GRAVING DOCKS), VIEW TO EAST-NORTHEAST AT THE SOUTH END OF THE CRANEWAY AND GALLERY BETWEEN BASINS NO. 1 AND 2, LOOKING ACROSS SOUTH END OF BASIN NO. 1 (THE WESTERN-MOST BASIN) - Rosie the Riveter National Historical Park, Graving Docks, Shipyard No. 3, Richmond, Contra Costa County, CA

  11. VIEW TO SOUTHEAST FROM NORTHWEST CORNER OF BASING NO. 4 ...

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

    VIEW TO SOUTHEAST FROM NORTHWEST CORNER OF BASING NO. 4 (SECOND BASING FROM THE EAST) SHOWING CRANEWAY AND GALLERY BETWEEN BASINS NO. 4 AND 5. GENERAL WAREHOUSE IS IN BACKGROUND - Rosie the Riveter National Historical Park, Graving Docks, Shipyard No. 3, Richmond, Contra Costa County, CA

  12. 12. VIEW TO NORTHEAST FROM WITHIN SERVICE OFFICE. THROUGH DOOR ...

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

    12. VIEW TO NORTHEAST FROM WITHIN SERVICE OFFICE. THROUGH DOOR IS LEFT IS DISTRIBUTOR OFFICE; THROUGH DOOR TO RIGHT IS WAITING ROOM AND STAIRS TO FIRST FLOOR. - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  13. 5. PERSPECTIVE VIEW TO EAST SHOWING NORTHWEST END AND SOUTHWEST ...

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

    5. PERSPECTIVE VIEW TO EAST SHOWING NORTHWEST END AND SOUTHWEST SIDE OF BUILDING. (NOTE THAT RIGHT PORTION OF PHOTOGRAPH WAS FOGGED DUE TO BELLOWS LEAK). - Rosie the Riveter National Historical Park, Auxiliary Plate Shop, 912 Harbour Way, Richmond, Contra Costa County, CA

  14. MARINA & MAINE STREETS FACING NW. DARKER COLORED HOME ON ...

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

    MARINA & MAINE STREETS FACING NW. DARKER COLORED HOME ON SE CORNER. NYSTROM VILLAGE, LIKE ATCHISON VILLAGE (HAER CA-326-N), HOUSED WORKERS DURING WORLD WAR II - Rosie the Riveter National Historical Park, Nystrom Village, Marina & Maine Streets, Richmond, Contra Costa County, CA

  15. 78 FR 40072 - Airworthiness Directives; Eurocopter France Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-03

    ...). SUMMARY: We propose to adopt a new airworthiness directive (AD) for certain serial-numbered Eurocopter... during a production modification. The proposed actions are intended to prevent failure of the... production line with non-conforming rivets installed on the RH and LH longitudinal beams Y350 of the...

  16. The Adult Learner: Some Things We Know

    ERIC Educational Resources Information Center

    Fogarty, Robin J.; Pete, Brian M.

    2007-01-01

    This book addresses the "warrior" who rises to the challenge of teaching the adult learner. The discussion is designed as a catalyst for dialogue about the adult learner and to uncover the complexities of teaching this rare and riveting species. This book is organized around three interlocking themes: some things we know about the adult learner;…

  17. 9. DETAIL OF ONE OF THE TWO CENTER PANELS IN ...

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

    9. DETAIL OF ONE OF THE TWO CENTER PANELS IN THE WEST TRUSS, SEEN FROM THE WEST, SHOWING POSTS, RIVETED PLATES, LOWER CHORDS, DIAGONAL EYE BARS WITH TURNBUCKLES, AND ENDS OF FLOOR BEAMS SUSPENDED FROM POSTS. - Mitchell's Mill Bridge, Spanning Winter's Run on Carrs Mill Road, west of Bel Air, Bel Air, Harford County, MD

  18. 18. DETAIL, L0 JOINT AND BEARING SEAT AT WEST ABUTMENT, ...

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

    18. DETAIL, L0 JOINT AND BEARING SEAT AT WEST ABUTMENT, FROM NORTH, SHOWING RIVETED CONNECTION OF BOTTOM CHORD AND END POST AT JOINT, AND FIXED SHOE - Glendale Road Bridge, Spanning Deep Creek Lake on Glendale Road, McHenry, Garrett County, MD

  19. 29 CFR 1926.62 - Lead.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 CFR 1910.1025(a)(2) is covered by this standard. Construction work is defined as work for... collection systems; (B) Spray painting with lead paint. (ii) In addition, with regard to tasks not listed in... are present: rivet busting; power tool cleaning without dust collection systems; cleanup...

  20. 78 FR 53640 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-30

    ... a case where two adjacent frame (FR) forks of a forward cargo door were found cracked. FR20B was... frame fork end of frame (FR)60 and FR60A of the aft cargo door for sheared, loose, or missing rivets... Register on May 20, 2013 (78 FR 29261). The NPRM proposed to correct an unsafe condition for the...

  1. 78 FR 29261 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-20

    ... states: One A330 operator recently reported a case where two adjacent frame (FR) forks of a forward cargo... frame fork end of frame (FR)60 and FR60A of the aft cargo door for sheared, loose, or missing rivets...-12, Amendment 39-17092 (77 FR 37797, June 25, 2012)] and ALI Task 523106-01-1. However, during...

  2. 6. VIEW OF THE EASTERN BRIDGE ELEVATION, SHOWING CENTRAL PIER ...

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

    6. VIEW OF THE EASTERN BRIDGE ELEVATION, SHOWING CENTRAL PIER AND ASSOCIATED SUPERSTRUCTURE, AND CANTILEVERED NORTHERN TRUSS SECTION. NOTE THE JOIN BETWEEN EYE-BAR (LEFT) AND RIVETED CHANNEL (RIGHT) LOWER BRIDGE CHORDS AT CENTER LEFT OF PHOTOGRAPH. FACING NORTH. - Coverts Crossing Bridge, Spanning Mahoning River along Township Route 372 (Covert Road), New Castle, Lawrence County, PA

  3. 30 CFR 57.6132 - Magazine requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives Storage... explosion hazard; (10) Locked when unattended; and (11) Used exclusively for the storage of explosive..., riveting, or the use of securely tightened bolts where individual metal portions are joined....

  4. 30 CFR 57.6132 - Magazine requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives Storage... explosion hazard; (10) Locked when unattended; and (11) Used exclusively for the storage of explosive..., riveting, or the use of securely tightened bolts where individual metal portions are joined....

  5. 30 CFR 57.6132 - Magazine requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives Storage... explosion hazard; (10) Locked when unattended; and (11) Used exclusively for the storage of explosive..., riveting, or the use of securely tightened bolts where individual metal portions are joined....

  6. 30 CFR 57.6132 - Magazine requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives Storage... explosion hazard; (10) Locked when unattended; and (11) Used exclusively for the storage of explosive..., riveting, or the use of securely tightened bolts where individual metal portions are joined....

  7. 49 CFR 195.205 - Repair, alteration and reconstruction of aboveground breakout tanks that have been in service.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... approximately atmospheric pressure constructed of carbon and low alloy steel, welded or riveted, and non... service must be capable of withstanding the internal pressure produced by the hazardous liquid to be..., examination, and material requirements of those respective standards. (3) For high pressure tanks built to...

  8. 49 CFR 179.200-22 - Test of tanks.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... evidence of distress. All rivets and closures, except safety relief valves or safety vents, shall be in... 49 Transportation 3 2011-10-01 2011-10-01 false Test of tanks. 179.200-22 Section 179.200-22 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS...

  9. 49 CFR 179.200-22 - Test of tanks.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... evidence of distress. All rivets and closures, except safety relief valves or safety vents, shall be in... 49 Transportation 3 2014-10-01 2014-10-01 false Test of tanks. 179.200-22 Section 179.200-22 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS...

  10. 49 CFR 179.200-22 - Test of tanks.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... evidence of distress. All rivets and closures, except safety relief valves or safety vents, shall be in... 49 Transportation 3 2012-10-01 2012-10-01 false Test of tanks. 179.200-22 Section 179.200-22 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS...

  11. 49 CFR 179.200-22 - Test of tanks.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... evidence of distress. All rivets and closures, except safety relief valves or safety vents, shall be in... 49 Transportation 3 2013-10-01 2013-10-01 false Test of tanks. 179.200-22 Section 179.200-22 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS...

  12. Sculpture, Metallic Formations II, Art Education: 6683.12b.

    ERIC Educational Resources Information Center

    Dubocq, Edward R.

    An exploratory course in the creation of shapes using a variety of metals and techniques is described in this guide for quinmester elective course for grades 7-12. Students cut, form, weld, rivet, cast and finish such metals as steel, copper, aluminum, brass, pewter, and bronze. They develop a working knowledge of the various tools and processes,…

  13. Celebrating Excellence: Learning and Teaching in Adult Higher Education. National Conference on Alternative and External Degree Programs for Adults (15th, Columbus, Ohio, October 5-7, 1995).

    ERIC Educational Resources Information Center

    Alliance, an Association for Alternative Degree Programs.

    These 23 presentations are organized in five categories: diversity, assessment, distance education, learning, and teaching. Five papers on diversity include the following: "From Rosie the Riveter to Comparable Worth: The Infusion of Gender and Women's Issues into an Interdisciplinary Curriculum for Working Adults" (Linda L. Hulbert, Theodore A.…

  14. 47 CFR 18.209 - Identification of authorized equipment.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Identification of authorized equipment. 18.209 Section 18.209 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL INDUSTRIAL, SCIENTIFIC, AND..., riveting, or a permanent adhesive. The label must be designed to last the expected lifetime of...

  15. View of north tower base panel and portion of concrete ...

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

    View of north tower base panel and portion of concrete abutment. Note riveted construction and dual-wire rope connections from counterweight to lift span on both sides. Lift wire ropes have been removed. - Potomac Edison Company, Chesapeake & Ohio Canal Bridge, Spanning C & O Canal South of U.S. 11, Williamsport, Washington County, MD

  16. 78 FR 51058 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-20

    ... side panel below the center wing box at STGR 42 on the LH and RH side between FR 40 and FR 42. (1) For... panels. Cracks were observed on both sides of the keel beam around the rivets below the center wing box... beam side panel below the center wing box and corrective actions , depending on findings. You...

  17. 49 CFR 236.743 - Dog, swing.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Dog, swing. 236.743 Section 236.743 Transportation... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.743 Dog, swing. A locking dog mounted in such a manner that it is free to rotate on a trunnion which is riveted to a...

  18. Teen Cyberbullying Investigated: Where Do Your Rights End and Consequences Begin?

    ERIC Educational Resources Information Center

    Jacobs, Thomas A.

    2010-01-01

    The Internet age has led to a different kind of teen bullying: cyberbullying. What is cyberbullying and what can teens do about it? In "Teen Cyberbullying Investigated," Judge Tom Jacobs presents a powerful collection of landmark court cases involving teens and charges of cyberbullying and cyberharassment. This riveting, informative guide will…

  19. 29 CFR 1910.217 - Mechanical power presses.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., hot bending and hot metal presses, forging presses and hammers, riveting machines and similar types of... equipment. Air controlling equipment shall be protected against foreign material and water entering the... shall be kept in good condition and free from obstructions, grease, oil, and water. (4) Overloading....

  20. 29 CFR 1910.217 - Mechanical power presses.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., hot bending and hot metal presses, forging presses and hammers, riveting machines and similar types of... equipment. Air controlling equipment shall be protected against foreign material and water entering the... shall be kept in good condition and free from obstructions, grease, oil, and water. (4) Overloading....

  1. 29 CFR 1910.217 - Mechanical power presses.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., hot bending and hot metal presses, forging presses and hammers, riveting machines and similar types of... equipment. Air controlling equipment shall be protected against foreign material and water entering the... surrounding floors shall be kept in good condition and free from obstructions, grease, oil, and water....

  2. 11. View showing detail of truss tower. The vertical, or ...

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

    11. View showing detail of truss tower. The vertical, or compression, members of the bridge are formed from two channel beams riveted together with lacing bars. The diagonal or tension members, are die-forged eyebars. - Center Street Swing Bridge, Southwest of Public Square, Cleveland, Cuyahoga County, OH

  3. 16 CFR Appendix to Part 23 - Exemptions Recognized in the Assay for Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled Gold Plate, Silver, and Platinum Industry..., Silver, and Platinum Industry Products (a) Exemptions recognized in the industry and not to be considered... in any assay for quality of a silver industry product include screws, rivets, springs, spring...

  4. 16 CFR Appendix to Part 23 - Exemptions Recognized in the Assay for Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled Gold Plate, Silver, and Platinum Industry..., Silver, and Platinum Industry Products (a) Exemptions recognized in the industry and not to be considered... in any assay for quality of a silver industry product include screws, rivets, springs, spring...

  5. 46 CFR 169.236 - Inspection and testing required.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... involving riveting, welding, burning, or other fire-producing actions may be made— (1) Within or on the... by the National Fire Protection Association; however, if the services of such certified marine... authorized person before the work is started. The certificate must include any requirements necessary...

  6. 46 CFR 176.710 - Inspection and testing prior to hot work.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... of NFPA 306 (incorporated by reference, see 46 CFR 175.600) before alterations, repairs, or other operations involving riveting, welding, burning, or other fire producing actions may be made aboard a vessel... authorized person before the work is started. The certificate must include any requirements necessary...

  7. 17. VIEW TO EAST SHOWING ONE OF THE OPENINGS IN ...

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

    17. VIEW TO EAST SHOWING ONE OF THE OPENINGS IN THE SECOND FLOOR EAST WALL THROUGH WHICH A CONVEYOR ONCE PASSED FOR MOVING BODY PANELS TO AND FROM THE SECOND FLOOR. - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  8. 18. VIEW TO EAST, DETAIL OF OPENING THROUGH THE SECOND ...

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

    18. VIEW TO EAST, DETAIL OF OPENING THROUGH THE SECOND FLOOR EAST WALL SHOWING CONVEYOR FOR MOVING MATERIAL TO THE SECOND FLOOR. (NOTE: THIS IS NOT AN ORIGINAL CONVEYOR FOR MOVING BODY PARTS). - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  9. 75 FR 15627 - Airworthiness Directives; Turbomeca Astazou XIV B and XIV H Turboshaft Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-30

    ... complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78... rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and 3. Will... riveted plugs, were introduced by modification AB 173 in order to improve the vibration characteristics...

  10. 78 FR 7308 - Airworthiness Directives; Bell Helicopter Textron Canada Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-01

    ... rivet, or other damage. This proposed AD is prompted by a stress analysis of the tailboom skin that revealed high-stress-concentration areas are susceptible to skin cracking. This condition, if not detected..., environmental, energy, or federalism impacts that might result from adopting the proposals in this document....

  11. Engineering Drawing II, 6-2. Military Curriculum Project for Vocational and Technical Education.

    ERIC Educational Resources Information Center

    Army Engineer School, Fort Belvoir, VA.

    This military-developed text consists of seven lessons to teach students with basic drafting skills more advanced techniques. Covered in the individual lessons are the following topics: auxiliary views; isometric drawing; screws, bolts, rivets, and welds; detail and assembly practices; intersections and developments; machine drawing; architectural…

  12. Creativity in Biographical Writing as the Necessary Fictions of Nonfiction.

    ERIC Educational Resources Information Center

    Feldman, Paula R.

    Biographical writing is highly imaginative writing and always has been. The task of the biographer is to weave a riveting story from the fabric of the subject's life. For example, a single pivotal incident in the lives of Percy Bysshe Shelley, the English poet, and Mary Godwin, author of "Frankenstein", at the grave of Mary's mother, Mary…

  13. 29 CFR 1915.4 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... repair of a vessel including, but not restricted to, alterations, conversions, installations, cleaning..., quarters, and machinery and boiler spaces. (r) The term hot work means riveting, welding, burning or other... regulations under 49 CFR part 178, subparts C and H. (u) The term powder actuated fastening tool means a...

  14. Detail, typical vertical member UL of south span, east truss, ...

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

    Detail, typical vertical member U-L of south span, east truss, showing riveted lacing bars and channels, and "Cambria" imprint, indicating Cambria Iron Company fabrication of member - Castle Garden Bridge, Township Route 343 over Bennetts Branch of Sinnemahoning Creek, Driftwood, Cameron County, PA

  15. 16. VIEW TO NORTHEAST OF SECONDFLOOR ASSEMBLY AREA FROM NEAR ...

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

    16. VIEW TO NORTHEAST OF SECOND-FLOOR ASSEMBLY AREA FROM NEAR SOUTHWEST WEST. NOTE DIFFERENCE IN ROOF STRUCTURE BETWEEN SAWTOOTH SKYLIGHTS OVER MOST OF THE SECOND FLOOR (RIGHT) AND THE PORTION OF THE ROOF RUNNING ALONG THE WEST EDGE OF THE BUILDING (LEFT). - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  16. The Cuban Missile Crisis: Considering Its Place in Cold War History. Teacher's Resource Book [and Student Text]. Public Policy Debate in the Classroom. Choices for the 21st Century Education Project. 4th Edition.

    ERIC Educational Resources Information Center

    Soukup, Nancy, Ed.

    Like no other region on the globe, the Caribbean Basin has served as a testing ground for U.S. foreign policy. Of all the countries in the region, Cuba has been the scene of many of the United States' most riveting foreign policy dramas. The teacher resource book and student text probe the complex, often troubled, relationship between the United…

  17. Lautal as a material for airplane construction

    NASA Technical Reports Server (NTRS)

    Brenner, Paul

    1929-01-01

    Lautal is a refinable aluminum alloy which, unlike duralumin, contains no magnesium. According to the statements of the Lauta Works, lautal contains: aluminum, 94%; copper, 4%; silicon, 2%. The use of lautal as a construction material is discussed in relation to specific weight, production methods, and riveting tests.

  18. 40 CFR 86.1833-01 - Adjustable parameters.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... return to its original shape after the force is removed (plastic or spring steel materials); (D) In the... bimetal spring, the plate covering the bimetal spring is riveted or welded in place, or held in place with... regardless of additional forces or torques applied to the adjustment; (C) The manufacturer demonstrates...

  19. 40 CFR 86.1833-01 - Adjustable parameters.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... return to its original shape after the force is removed (plastic or spring steel materials); (D) In the... bimetal spring, the plate covering the bimetal spring is riveted or welded in place, or held in place with... regardless of additional forces or torques applied to the adjustment; (C) The manufacturer demonstrates...

  20. 40 CFR 86.094-22 - Approval of application for certification; test fleet selections; determinations of parameters...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... the force is removed (plastic or spring steel materials); (D) In the case of any parameter, the... for $20 (1978 dollars) or less; (B) In the case of a choke bimetal spring, the plate covering the bimetal spring is riveted or welded in place, or held in place with nonreversible screws; (C) In the...

  1. 40 CFR 86.1833-01 - Adjustable parameters.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... return to its original shape after the force is removed (plastic or spring steel materials); (D) In the... bimetal spring, the plate covering the bimetal spring is riveted or welded in place, or held in place with... regardless of additional forces or torques applied to the adjustment; (C) The manufacturer demonstrates...

  2. 15. Detail along the northwest side of the inside of ...

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

    15. Detail along the northwest side of the inside of the bridge, showing the latticed vertical post that separates the second from the third panel point on the southwest end; the latticed top strut is rivet-connected to the vertical post and the top strut. - Post Road Bridge, State Route 7-A, Havre de Grace, Harford County, MD

  3. Ultimate Stresses Developed by 24S-T Sheet in Incomplete Diagonal Tension

    NASA Technical Reports Server (NTRS)

    Kuhn, Paul

    1941-01-01

    Tests were made on 18 shear panels of 24S-T aluminum alloy to verify the dependence of the ultimate stress on the degree of development of the diagonal-tension field. Tests were made on two thicknesses of sheet with the sheet either clamped between the flange angle or riveted to the outside of the angles.

  4. 49 CFR 236.743 - Dog, swing.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Dog, swing. 236.743 Section 236.743 Transportation... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.743 Dog, swing. A locking dog mounted in such a manner that it is free to rotate on a trunnion which is riveted to a...

  5. 49 CFR 236.743 - Dog, swing.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Dog, swing. 236.743 Section 236.743 Transportation... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.743 Dog, swing. A locking dog mounted in such a manner that it is free to rotate on a trunnion which is riveted to a...

  6. 49 CFR 236.743 - Dog, swing.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Dog, swing. 236.743 Section 236.743 Transportation... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.743 Dog, swing. A locking dog mounted in such a manner that it is free to rotate on a trunnion which is riveted to a...

  7. 20. VIEW TO WEST OF INTERIOR OF CRANEWAY WITH TOW ...

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

    20. VIEW TO WEST OF INTERIOR OF CRANEWAY WITH TOW TRAVELING BRIDGE CRANES (ONE OVERHEAD IN FOREGROUND AND ONE OVERHEAD IN BACKGROUNDS). NOTE WOOD BLOCK PAVING ON THE FLOOR. FIRST FLOOR ASSEMBLY AREA IS THE SPACE IN THE BACKGROUND ON THE RIGHT. - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  8. 49 CFR 236.743 - Dog, swing.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Dog, swing. 236.743 Section 236.743 Transportation... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.743 Dog, swing. A locking dog mounted in such a manner that it is free to rotate on a trunnion which is riveted to a...

  9. 13. DETAIL OF CONNECTION BETWEEN TOP CHORD AND POST IN ...

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

    13. DETAIL OF CONNECTION BETWEEN TOP CHORD AND POST IN WEST TRUSS, SHOWING CHANNELS AND REINFORCED CAST-IRON LACING, I-BEAMS FASTENED TOGETHER WITH RIVETTED PLATES, AND ASSEMBLY OF DIAGONAL EYE BEAM AND BOLT; VIEW FROM EAST SIDE. - Mitchell's Mill Bridge, Spanning Winter's Run on Carrs Mill Road, west of Bel Air, Bel Air, Harford County, MD

  10. An alternative fabrication method of the dart thrower's motion orthosis (also known as the dart orthosis).

    PubMed

    Schwartz, Deborah A

    2016-01-01

    To allow safe early wrist motion after wrist injury, this author has modified an earlier version of a dart thrower's motion orthotic device using material that is currently available on the market and an inexpensive paper fastener as the rivet. - KristinValdes, OTD, OT, CHT, Practice Forum Editor. PMID:27496989

  11. 49 CFR 230.20 - Alteration and repair report for steam locomotive boilers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... boilers. (a) Alterations. When an alteration is made to a steam locomotive boiler, the steam locomotive... steam locomotive boiler, the steam locomotive owner and/or operator shall file with the FRA Regional... the boiler. Whenever welded or riveted repairs are performed on stayed portions of a steam...

  12. 49 CFR 230.20 - Alteration and repair report for steam locomotive boilers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... boilers. (a) Alterations. When an alteration is made to a steam locomotive boiler, the steam locomotive... steam locomotive boiler, the steam locomotive owner and/or operator shall file with the FRA Regional... the boiler. Whenever welded or riveted repairs are performed on stayed portions of a steam...

  13. 49 CFR 230.20 - Alteration and repair report for steam locomotive boilers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... boilers. (a) Alterations. When an alteration is made to a steam locomotive boiler, the steam locomotive... steam locomotive boiler, the steam locomotive owner and/or operator shall file with the FRA Regional... the boiler. Whenever welded or riveted repairs are performed on stayed portions of a steam...

  14. 49 CFR 230.20 - Alteration and repair report for steam locomotive boilers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... boilers. (a) Alterations. When an alteration is made to a steam locomotive boiler, the steam locomotive... steam locomotive boiler, the steam locomotive owner and/or operator shall file with the FRA Regional... the boiler. Whenever welded or riveted repairs are performed on stayed portions of a steam...

  15. 49 CFR 230.20 - Alteration and repair report for steam locomotive boilers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... boilers. (a) Alterations. When an alteration is made to a steam locomotive boiler, the steam locomotive... steam locomotive boiler, the steam locomotive owner and/or operator shall file with the FRA Regional... the boiler. Whenever welded or riveted repairs are performed on stayed portions of a steam...

  16. Lessons: Katrina and Beginning Anew

    ERIC Educational Resources Information Center

    Kirylo, James D.

    2005-01-01

    New Orleans, fondly known in better days for its spectacular cuisine, cool jazz, and good times, was the leading story on television news broadcasts the world over when a massive hurricane came. As Katrina took its destructive path, culminating in the devastating rupture of ill-prepared levee systems, the world was riveted by stories about the…

  17. 46 CFR 189.50-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., repairs, or other such operations involving riveting, welding, burning, or like fire-producing actions..., welding, burning, or like fire-producing actions. (a) The provisions of “Standard for the Control of Gas..., burning, welding, or like fire-producing actions shall be made: (1) Within or on the boundaries of...

  18. 46 CFR 59.10-30 - Seal welding.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Seal welding. 59.10-30 Section 59.10-30 Shipping COAST... VESSELS AND APPURTENANCES Welding Repairs to Boilers and Pressure Vessels in -Service § 59.10-30 Seal welding. Where leaks occur in riveted joints or connections, they shall be carefully investigated...

  19. 46 CFR 59.10-30 - Seal welding.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Seal welding. 59.10-30 Section 59.10-30 Shipping COAST... VESSELS AND APPURTENANCES Welding Repairs to Boilers and Pressure Vessels in -Service § 59.10-30 Seal welding. Where leaks occur in riveted joints or connections, they shall be carefully investigated...

  20. 46 CFR 59.10-30 - Seal welding.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Seal welding. 59.10-30 Section 59.10-30 Shipping COAST... VESSELS AND APPURTENANCES Welding Repairs to Boilers and Pressure Vessels in -Service § 59.10-30 Seal welding. Where leaks occur in riveted joints or connections, they shall be carefully investigated...

  1. 46 CFR 189.50-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., repairs, or other such operations involving riveting, welding, burning, or like fire-producing actions..., welding, burning, or like fire-producing actions. (a) The provisions of “Standard for the Control of Gas..., burning, welding, or like fire-producing actions shall be made: (1) Within or on the boundaries of...

  2. 46 CFR 59.10-30 - Seal welding.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Seal welding. 59.10-30 Section 59.10-30 Shipping COAST... VESSELS AND APPURTENANCES Welding Repairs to Boilers and Pressure Vessels in -Service § 59.10-30 Seal welding. Where leaks occur in riveted joints or connections, they shall be carefully investigated...

  3. 46 CFR 59.10-30 - Seal welding.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Seal welding. 59.10-30 Section 59.10-30 Shipping COAST... VESSELS AND APPURTENANCES Welding Repairs to Boilers and Pressure Vessels in -Service § 59.10-30 Seal welding. Where leaks occur in riveted joints or connections, they shall be carefully investigated...

  4. 46 CFR 189.50-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., repairs, or other such operations involving riveting, welding, burning, or like fire-producing actions..., welding, burning, or like fire-producing actions. (a) The provisions of “Standard for the Control of Gas..., burning, welding, or like fire-producing actions shall be made: (1) Within or on the boundaries of...

  5. 46 CFR 189.50-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., repairs, or other such operations involving riveting, welding, burning, or like fire-producing actions..., welding, burning, or like fire-producing actions. (a) The provisions of “Standard for the Control of Gas..., burning, welding, or like fire-producing actions shall be made: (1) Within or on the boundaries of...

  6. 46 CFR 189.50-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., repairs, or other such operations involving riveting, welding, burning, or like fire-producing actions..., welding, burning, or like fire-producing actions. (a) The provisions of “Standard for the Control of Gas..., burning, welding, or like fire-producing actions shall be made: (1) Within or on the boundaries of...

  7. 78 FR 78703 - Airworthiness Directives; The Boeing Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-27

    ... that the aft pressure bulkhead web area is subject to widespread fatigue damage (WFD). This AD requires modifying the aft pressure bulkhead. The modification includes inspecting for cracks around the rivet holes, and repair of any cracking. We are issuing this AD to prevent fatigue cracking of the aft...

  8. 49 CFR 195.205 - Repair, alteration and reconstruction of aboveground breakout tanks that have been in service.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... approximately atmospheric pressure constructed of carbon and low alloy steel, welded or riveted, and non... service must be capable of withstanding the internal pressure produced by the hazardous liquid to be..., examination, and material requirements of those respective standards. (3) For high pressure tanks built to...

  9. 49 CFR 195.205 - Repair, alteration and reconstruction of aboveground breakout tanks that have been in service.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... approximately atmospheric pressure constructed of carbon and low alloy steel, welded or riveted, and non... service must be capable of withstanding the internal pressure produced by the hazardous liquid to be..., examination, and material requirements of those respective standards. (3) For high pressure tanks built to...

  10. 49 CFR 195.205 - Repair, alteration and reconstruction of aboveground breakout tanks that have been in service.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... approximately atmospheric pressure constructed of carbon and low alloy steel, welded or riveted, and non... service must be capable of withstanding the internal pressure produced by the hazardous liquid to be..., examination, and material requirements of those respective standards. (3) For high pressure tanks built to...

  11. 49 CFR 195.205 - Repair, alteration and reconstruction of aboveground breakout tanks that have been in service.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... approximately atmospheric pressure constructed of carbon and low alloy steel, welded or riveted, and non... service must be capable of withstanding the internal pressure produced by the hazardous liquid to be..., examination, and material requirements of those respective standards. (3) For high pressure tanks built to...

  12. Dear Mr. Kozol. . . . Four African American Women Scholars and the Re-Authoring of Savage Inequalities

    ERIC Educational Resources Information Center

    Farmer-Hinton, Raquel; Lewis, Joi D.; Patton, Lori D.; Rivers, Ishwanzya D.

    2013-01-01

    Background: In 1991, Savage Inequalities quickly became the most riveting assessment of the inequalities in U.S. public schools. When Kozol visited East St. Louis for his book, the authors of this paper lived and attended schools there. As Kozol's readers in their respective graduate and undergraduate classes, the authors found it difficult…

  13. 77 FR 37797 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-25

    ... frame (FR) fork ends. In addition, during a scheduled maintenance check, the aft cargo door frame 64A of... fork ends, as well as cracks of the aft cargo door frame 64A. This AD requires performing a detailed inspection of the outer skin rivets at the frame fork ends of the forward and aft cargo door for...

  14. The Rosenberg Trial: Uncovering the Layers of History

    ERIC Educational Resources Information Center

    Ragsdale, Bruce A.

    2013-01-01

    The trial of Julius and Ethel Rosenberg on charges of conspiring to spy for the Soviet Union remains one of the defining moments of the Cold War era. The dramatic allegations of stolen atomic secrets and networks of Communist spies riveted the public's attention. The determination of government prosecutors reflected a widely shared belief…

  15. Robotics 101

    ERIC Educational Resources Information Center

    Sultan, Alan

    2011-01-01

    Robots are used in all kinds of industrial settings. They are used to rivet bolts to cars, to move items from one conveyor belt to another, to gather information from other planets, and even to perform some very delicate types of surgery. Anyone who has watched a robot perform its tasks cannot help but be impressed by how it works. This article…

  16. 77 FR 63270 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-16

    ... of an A320 family aeroplane, it was discovered that a fastener was missing at FR 24 between stringer... aluminum rivet, Part Number (P/N) ASNA2050DXJ040, is to connect the FR 24 to the FR 24 Tee. The hole where... Policies and Procedures (44 FR 11034, February 26, 1979); 3. Will not affect intrastate aviation in...

  17. Civil Rights Milestones Offer Lessons

    ERIC Educational Resources Information Center

    Malveaux, Julianne

    2004-01-01

    The landmark legal decision, Brown v. Board of Education, was rendered on May 17, 1954. Fifty years later, campuses and communities are commemorating the decision and its impact on contemporary life. The Harvard legal scholar, Charles Ogletree, has published a riveting book of his reflections, a government commission is staging a variety of…

  18. Best Reference 2008

    ERIC Educational Resources Information Center

    Coutts, Brian E.; LaGuardia, Cheryl

    2009-01-01

    America's subprime mortgage crisis of 2007 spiraled into a global financial crisis in 2008. For much of the year, attention was riveted on the presidential primaries. A worsening economy made the election somewhat anticlimactic, but everybody rejoiced with the choice of the first "international" President. With stocks tumbling and major firms…

  19. Effect of polymer coatings on fatigue strength of aluminum alloy 2024 box beams

    NASA Technical Reports Server (NTRS)

    Nordmark, G. E.; Kelsey, R. A.

    1972-01-01

    Previous investigators have shown that polymer coatings raise the fatigue strength of metals tested in air to about the same level as that of uncoated specimens tested in vacuum. The results are given of tests to determine if a polymer coating would improve the fatigue strength of built-up aluminum alloy members simulating aircraft construction. Aluminum alloy 2024-T4 riveted box beams were subjected to constant amplitude fatigue tests in air as well as in salt water fog. The coating did not improve the fatigue strength of beams tested in either environment. This is believed to result from the fact that most failures originated at rivet holes, which were isolated from both the coating and the environment.

  20. Mechanical fastening solution with a sealing undercut which ensures a uniform force transmission

    NASA Astrophysics Data System (ADS)

    Krugmann, J.; Moritzer, E.

    2014-05-01

    Whereas metal rivet connections are well-researched and are used especially with lightweight structures [1], plastic rivet connections are still in need of further research. The fastening solution presented here represents an alternative to existing connections. Through the direct molding-on of a boss with an optimized geometry, a mechanical connection is created with a uniform sealing undercut over the entire circumference. The method of direct screwing assumes significant importance in the development of the new fastening solution. It is only the introduction of the threaded screw that creates the axial tension for the compression of the boss, and thus, together with the necessary preload force, secures the connection. The characteristic features of the fastening element are one-side accessibility (blind joint), uniform force transmission and simultaneous sealing of the connection.

  1. Neck-band retention for Canada geese in the Mississippi (USA) flyway

    USGS Publications Warehouse

    Samuel, M.D.; Weiss, N.T.; Rusch, D.H.; Craven, S.R.; Trost, R.E.; Caswell, F.D.

    1990-01-01

    We used capture, harvest, and observation histories of Canada geese (Branta canadensis) banded in the Mississippi flyway, 1974-88, to examine the problem of neck-band retention. Methods for the analysis of survival data were used to estimate rates of neck-band retention and to evaluate factors associated with neck-band loss. Sex, age of bird at banding, rivet use, and neck-band type significantly influenced neck-band retention. For most of the resulting cohorts (e.g., sex, age, rivet, and neck-band type categories), neck-band retention rates decreased through time. We caution against using small samples or data collected during short-term studies to determine retention rates. We suggest that observation data be used in neck-band retention studies to increase the efficiency of estimating retention time.

  2. NASA airframe structural integrity program

    NASA Technical Reports Server (NTRS)

    Harris, Charles E.

    1991-01-01

    NASA has initiated a research program with the long-term objective of supporting the aerospace industry in addressing issues related to the aging commercial transport fleet. The interdisciplinary program combines advanced fatigue crack growth prediction methodology with innovative nondestructive examination technology with the focus on multi-site damage (MSD) at riveted connections. A fracture mechanics evaluation of the concept of pressure proof testing the fuselage to screen for MSD has been completed. Also, a successful laboratory demonstration of the ability of the thermal flux method to detect disbonds at riveted lap splice joints has been conducted. All long-term program elements have been initiated and the plans for the methodology verification program are being coordinated with the airframe manufacturers.

  3. VIEW TO EAST OF THE NORTH END OF BASIN NO. ...

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

    VIEW TO EAST OF THE NORTH END OF BASIN NO. 1 (THE WESTERN-MOST BASIN) SHOWING THE CRANEWAY AND GALLERY BETWEEN BASINS NO. 1 AND 2. BASSWOOD BUOY TENDER AND THREE SMALL VESSELS ARE BERTHED IN BASIN NO. 1. LARGER VESSELS ARE BERTHED IN BASINS TO THE EAST, SEEN IN BACKGROUND - Rosie the Riveter National Historical Park, Graving Docks, Shipyard No. 3, Richmond, Contra Costa County, CA

  4. RIGGERS LOFT/PAINT SHOP/SHEET METAL SHOP, VIEW TO SOUTHEAST. THE PAINT ...

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

    RIGGERS LOFT/PAINT SHOP/SHEET METAL SHOP, VIEW TO SOUTHEAST. THE PAINT SHOP WAS LOCATED IN THE CLOSEST CORNER OF THE BUILDING. THE SHEET METAL SHOP WAS LOCATED IN THE CORNER OF THE BUILDING ON THE RIGHT. THE RIGGERS LOFT WAS LOCATED IN THE PORTION OF THE BUILDING OUT OF VIEW TO THE LEFT - Rosie the Riveter National Historical Park, Riggers Loft/Paint Shop/Sheet Metal Shop, 1322 Canal Boulevard, Richmond, Contra Costa County, CA

  5. In-flight measurements of the GA/W/-2 aerodynamic characteristics

    NASA Technical Reports Server (NTRS)

    Gregorek, G. M.; Hoffmann, M. J.; Weislogel, G. S.; Vogel, G. M.

    1977-01-01

    Flight tests of a new 13% General Aviation Airfoil - the GA(W)-2 - gloved full span onto the existing wing of a Beech Sundowner have generated chordwise pressure distributions and wake surveys. Section lift, drag and moment coefficients derived from these measurements verify wind tunnel data and theory predicting the performance of this airfoil. The effect of steps, rivets and surface coatings upon the drag of the GA(W)-2 was also evaluated.

  6. Prosthetic Tool For Holding Small Ferromagnetic Parts

    NASA Technical Reports Server (NTRS)

    Norton, William E.; Carden, James R.; Belcher, Jewell G., Jr.; Vest, Thomas W.

    1995-01-01

    Tool attached to prosthetic hand or arm enables user to hold nails, screws, nuts, rivets, and other small ferromagnetic objects on small magnetic tip. Device adjusted to hold nail or screw at proper angle for hammering or for use of screwdriver, respectively. Includes base connector with threaded outer surface and lower male member inserted in standard spring-action, quick-connect/quick-disconnect wrist adapter on prosthetic hand or arm.

  7. Fastener Design Course [Workbook

    NASA Technical Reports Server (NTRS)

    Barrett, Richart T.

    1997-01-01

    Richard T. Barrett, Senior Aerospace Engineer of NASA Lewis Research Center presents a comprehensive course on fastener design. A recognized expert in the field of fastener technology Mr. Barrett combines lecture, charts, illustrations with real-world experiences. Topics covered include: materials, plantings and coatings, locking methods threads, joint stiffness, rivets, inserts, nut plates, thread lubricants, design criteria, etc. These presentation slides accompany the DVD.

  8. A Summary of Diagonal Tension Part I : Methods of Analysis

    NASA Technical Reports Server (NTRS)

    Kuhn, Paul; Peterson, James P; Levin, L Ross

    1952-01-01

    Previously published methods for stress and strength analysis of plane and curved shear webs working in diagonal tension are presented as a unified method. The treatment is sufficiently comprehensive and detailed to make the paper self-contained. Part 1 discusses the theory and methods for calculating the stresses and shear deflections of web systems as well as the strengths of the web, the stiffeners, and the riveting. Part 2, published separately, presents the experimental evidence. (author)

  9. HOT METAL BRIDGE (NOTE: BUILDERS: JONES AND LAUGHLIN STEEL CA. ...

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

    HOT METAL BRIDGE (NOTE: BUILDERS: JONES AND LAUGHLIN STEEL CA. 1890), SOUTH PORTAL. THREE PIN CONNECTED CAMELBACK TRUSS SPANS, ONE SKEWED THROUGH TRUSS SPAN ON NORTH SIDE TRUSS BRIDGE, EAST OF HOT METAL BRIDGE BUILT BY AMERICAN BRIDGE COMPANY CA. 1910. (RIVETED MULTI-SPAN TRUSS). - Jones & Laughlin Steel Corporation, Pittsburgh Works, Morgan Billet Mill Engine, 550 feet north of East Carson Street, opposite South Twenty-seventh Street, Pittsburgh, Allegheny County, PA

  10. First-Person Assignments: Considering How History Affects and Is Affected by the Individual

    ERIC Educational Resources Information Center

    Johansen, Mary Carroll

    2014-01-01

    This author is an avid consumer of history and has a desire to open students to the endless supply of the riveting stories of men and women struggling to cope with a changing world. The fascination toward the people of the past is enthralling history, and students need to feel that same sense of wonder and love of history. To accomplish this goal,…

  11. 13. SOUTHEAST TO SUCKER ROD WORK BENCH AND WOODEN SUCKER ...

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

    13. SOUTHEAST TO SUCKER ROD WORK BENCH AND WOODEN SUCKER ROD STORAGE RACKS ALONG EAST WALL OF FACTORY INTERIOR. AT THIS BENCH WORKERS RIVETED THREADED WROUGHT IRON CONNECTORS TO THE ENDS OF 20' LONG WOODEN SUCKER RODS (THE RODS WHICH EXTEND DOWNWARD IN THE WELL FROM THE GROUND SURFACE TO PISTON DISPLACEMENT PUMPS WHICH ACTUALLY ELEVATE WATER TO THE SURFACE). ROZNOR HEATER AT THE FAR RIGHT WAS ADDED CIRCA 1960. - Kregel Windmill Company Factory, 1416 Central Avenue, Nebraska City, Otoe County, NE

  12. Beyond the Simple Model of Child Care Facilities: Support Spaces for Quality

    ERIC Educational Resources Information Center

    Greenman, Jim

    2006-01-01

    The age of child care building on a wide scale really began in the 1970s. Before that, there had been a history of day nurseries going back to the turn of the century and Lanham Act centers during World War II to provide care for "Rosie the Riveter" mothers in the work force. The "purpose built" child care center was an economical box with almost…

  13. Small Fixture Strains Composites for Environmental Tests

    NASA Technical Reports Server (NTRS)

    Tervet, F. W.

    1982-01-01

    Fixture for long-term strain tests of composites is based on inexpensive tool for repairing motorcycle chains. (In normal use tool forces rivet out of chain element.) As modified for composite testing, tool has precision screw and shim. Qualification tests for graphite/epoxy composites are made less expensive by simple test fixture. Used in quantity, fixtures apply precisely similar loads to many samples.

  14. Autonomous Deicing System For Airplane Wing

    NASA Technical Reports Server (NTRS)

    Hickman, G. A.; Gerardi, J. J.

    1993-01-01

    Prototype autonomous deicing system for airplane includes network of electronic and electromechanical modules at various locations in wings and connected to central data-processing unit. Small, integrated solid-state device, using long coils installed under leading edge, exciting small vibrations to detect ice and larger vibrations to knock ice off. In extension of concept, outputs of vibration sensors and other sensors used to detect rivet-line fractures, fatigue cracks, and other potentially dangerous defects.

  15. Particle contamination from Martin Optical Black. [in design of barrel baffle of Infrared Astronomical Satellite

    NASA Technical Reports Server (NTRS)

    Young, P. J.; Noll, R.; Andreozzi, L.; Hope, J.

    1981-01-01

    The design of the barrel baffle of the Infrared Astronomical Satellite (IRAS) Optical Subsystem to minimize production of particulate contamination is described. The configuration of the 50-inch long, 28.5-inch diameter baffle required pop-rivet assembly after coating with Martin Optical Black for stray light suppression. An experiment to determine the contamination produced at assembly led to the modification of the baffle construction to preclude such damage to the coated surfaces.

  16. Particle contamination from Martin Optical Black

    NASA Astrophysics Data System (ADS)

    Young, P. J.; Noll, R.; Andreozzi, L.; Hope, J.

    The design of the barrel baffle of the Infrared Astronomical Satellite (IRAS) Optical Subsystem to minimize production of particulate contamination is described. The configuration of the 50-inch long, 28.5-inch diameter baffle required pop-rivet assembly after coating with Martin Optical Black for stray light suppression. An experiment to determine the contamination produced at assembly led to the modification of the baffle construction to preclude such damage to the coated surfaces.

  17. MCPLOTS: a particle physics resource based on volunteer computing

    NASA Astrophysics Data System (ADS)

    Karneyeu, A.; Mijovic, L.; Prestel, S.; Skands, P. Z.

    2014-02-01

    The mcplots.cern.ch web site ( mcplots) provides a simple online repository of plots made with high-energy-physics event generators, comparing them to a wide variety of experimental data. The repository is based on the hepdata online database of experimental results and on the rivet Monte Carlo analysis tool. The repository is continually updated and relies on computing power donated by volunteers, via the lhc@home 2.0 platform.

  18. Vibration and recoil control of pneumatic hammers. [by air flow pressure regulation

    NASA Technical Reports Server (NTRS)

    Constantinescu, I. N.; Darabont, A. V.

    1974-01-01

    Vibration sources are described for pneumatic hammers used in the mining industry (pick hammers), in boiler shops (riveting hammers), etc., bringing to light the fact that the principal vibration source is the variation in air pressure inside the cylinder. The present state of the art of vibration control of pneumatic hammers as it is practiced abroad, and the solutions adopted for this purpose, are discussed. A new type of pneumatic hammer with a low noise and vibration level is presented.

  19. Four paths of competition

    SciTech Connect

    Studness, C.M.

    1995-05-01

    The financial community`s focus on utility competition has been riveted on the proceedings now in progress at state regulatory commissions. The fear that something immediately damaging will come out of these proceedings seems to have diminished in recent months, and the stock market has reacted favorably. However, regulatory developments are only one of four paths leading to competition; the others are the marketplace, the legislatures, and the courts. Each could play a critical role in the emergence of competition.

  20. Enterococcus faecalis 6-Phosphogluconolactonase Is Required for Both Commensal and Pathogenic Interactions with Manduca sexta

    PubMed Central

    Holt, Jonathan F.; Frank, Kristi L.; Du, Jing; Guan, Changhui; Handelsman, Jo

    2014-01-01

    Enterococcus faecalis is a commensal and pathogen of humans and insects. In Manduca sexta, E. faecalis is an infrequent member of the commensal gut community, but its translocation to the hemocoel results in a commensal-to-pathogen switch. To investigate E. faecalis factors required for commensalism, we identified E. faecalis genes that are upregulated in the gut of M. sexta using recombinase-based in vivo expression technology (RIVET). The RIVET screen produced 113 clones, from which we identified 50 genes that are more highly expressed in the insect gut than in culture. The most frequently recovered gene was locus OG1RF_11582, which encodes a 6-phosphogluconolactonase that we designated pglA. A pglA deletion mutant was impaired in both pathogenesis and gut persistence in M. sexta and produced enhanced biofilms compared with the wild type in an in vitro polystyrene plate assay. Mutation of four other genes identified by RIVET did not affect persistence in caterpillar guts but led to impaired pathogenesis. This is the first identification of genetic determinants for E. faecalis commensal and pathogenic interactions with M. sexta. Bacterial factors identified in this model system may provide insight into colonization or persistence in other host-associated microbial communities and represent potential targets for interventions to prevent E. faecalis infections. PMID:25385794

  1. A low-cost method to identify tubewells for longitudinal research on arsenic in groundwater.

    PubMed

    Sugimoto, Jonathan D; Ahmad, Salahuddin; Rashid, Mahbubur; Shamim, Abu Ahmed; Labrique, Alain B

    2007-09-01

    Exposure to high concentrations of arsenic in tubewell groundwater from the shallow aquifers of Bangladesh could result in up to 300,000 arsenic-related cancer cases over the next four decades. Understanding the magnitude and temporal dynamics of this exposure, via longitudinal studies, is imperative for planning effective mitigation and management strategies. Appropriate methods are needed to identify tubewells for longitudinal sampling. A plastic band marked with a unique identification number was developed, and various methods for attaching the band to the tubewell were tested, resulting in the choice of a galvanized-iron split-rivet. Two follow-up surveys at two and 14 months post-banding assessed the durability and longevity under field conditions in the JiVitA Project area in rural, northwestern Bangladesh. After two months, approximately 96.0% of the original bands on 1,063 tubewells were functional, although the rivets were partially corroded. After 14 months, approximately 65% of a subsample of the bands were functional. With further improvements to the rivets, these bands offer an inexpensive, durable, enumeration technology for longitudinal studies on groundwater arsenic.

  2. Structural analysis of Aircraft fuselage splice joint

    NASA Astrophysics Data System (ADS)

    Udaya Prakash, R.; Kumar, G. Raj; Vijayanandh, R.; Senthil Kumar, M.; Ramganesh, T.

    2016-09-01

    In Aviation sector, composite materials and its application to each component are one of the prime factors of consideration due to the high strength to weight ratio, design flexibility and non-corrosive so that the composite materials are widely used in the low weight constructions and also it can be treated as a suitable alternative to metals. The objective of this paper is to estimate and compare the suitability of a composite skin joint in an aircraft fuselage with different joints by simulating the displacement, normal stress, vonmises stress and shear stress with the help of numerical solution methods. The reference Z-stringer component of this paper is modeled by CATIA and numerical simulation is carried out by ANSYS has been used for splice joint presents in the aircraft fuselage with three combinations of joints such as riveted joint, bonded joint and hybrid joint. Nowadays the stringers are using to avoid buckling of fuselage skin, it has joined together by rivets and they are connected end to end by splice joint. Design and static analysis of three-dimensional models of joints such as bonded, riveted and hybrid are carried out and results are compared.

  3. A Low-cost Method to Identify Tubewells for Longitudinal Research on Arsenic in Groundwater

    PubMed Central

    Sugimoto, Jonathan D.; Ahmad, Salahuddin; Rashid, Mahbubur; Shamim, Abu Ahmed; Labrique, Alain B.

    2007-01-01

    Exposure to high concentrations of arsenic in tubewell groundwater from the shallow aquifers of Bangladesh could result in up to 300,000 arsenic-related cancer cases over the next four decades. Understanding the magnitude and temporal dynamics of this exposure, via longitudinal studies, is imperative for planning effective mitigation and management strategies. Appropriate methods are needed to identify tubewells for longitudinal sampling. A plastic band marked with a unique identification number was developed, and various methods for attaching the band to the tubewell were tested, resulting in the choice of a galvanized-iron split-rivet. Two follow-up surveys at two and 14 months post-banding assessed the durability and longevity under field conditions in the JiVitA Project area in rural, northwestern Bangladesh. After two months, ~96.0% of the original bands on 1,063 tubewells were functional, although the rivets were partially corroded. After 14 months, ~65% of a subsample of the bands were functional. With further improvements to the rivets, these bands offer an inexpensive, durable, enumeration technology for longitudinal studies on groundwater arsenic. PMID:18330072

  4. Evaluation of the Self-Nulling Rotating Eddy Current Probe System

    NASA Technical Reports Server (NTRS)

    Hagemaier, Don; Rengel, Kent; Wincheski, Buzz; Namkung, Min

    1999-01-01

    In order to detect multi-site fatigue cracks located under flush-head rivets, automated eddy current equipment is required. To assure a reliable system, the eddy current probe must be centered easily over the installed rivets. To meet these requirements, the NDE Group at NASA LaRC developed the Self-Nulling Rotating Eddy Current Probe System (SNRECPS) which will be referred to as RPS in this document. The system was evaluated at the FAA, NDI Validation Center, in Albuquerque, New Mexico. The system was capable of detecting a 0.032 inch long crack with a 90/95% PoD. Further evaluations were conducted at Boeing in Long Beach, California. These evaluations included fatigue cracks and notches in a range from 0.025 to 0.100 inch long under flush-head aluminum rivets, and titanium or steel flush-head fasteners. The results of these tests are reported herein. Subsequently, the system was loaned to the USAF Structures Laboratory for the purpose of detecting and measuring short cracks under flush-head rivets in a variety of fatigue test specimens. The inspection task was to detect and plot crack growth from numbered fasteners in lettered rows. In January, 1998, the system was taken to Northwest Airlines Maintenance Base, in Atlanta, to inspect a DC-9, for multi-site cracks in three circumferential splices. The aircraft had 83,000 cycles. The inspection was conducted at 30 kHz from longeron 5 left to longeron 5 right. The system was calibrated using a 0,030 EDM first layer notch. The instrument gain was set to 19 mV from the notch. The reject level was set at 10 mV and the unflawed fasteners yielded a signal amplitude of 2 to 3 mV. Only one fastener location, out of about 2,500 tested, yielded a signal of 58 mV. The rivet was removed and visually evaluated. It appeared to be a slight gouge in the counter-sink zone. No fatigue cracks were detected. The same fastener locations were also inspected using the Boeing MAUS system at 60 kHz. No cracks were detected. Thus far, the

  5. Fracture analyses of thin films, interfaces, and joints

    NASA Astrophysics Data System (ADS)

    Beuth, Jack Lee, Jr.

    multi-site damage (multiple small fatigue cracks emerging from rivet holes along a single line of rivets) in the lap joints of the skins of aging aircraft. Stress intensity factors are plotted as a function of normalized crack length for two types of rivet contact conditions. The roles of transverse stresses and residual stresses induced by the riveting process are explored. The underlying cause of MSD cracking is investigated, including the potential influence of the shedding of load from one cracked rivet hole to a lesser cracked neighbor.

  6. Robotic collaborative technology alliance: an open architecture approach to integrated research

    NASA Astrophysics Data System (ADS)

    Dean, Robert Michael S.; DiBerardino, Charles A.

    2014-06-01

    The Robotics Collaborative Technology Alliance (RCTA) seeks to provide adaptive robot capabilities which move beyond traditional metric algorithms to include cognitive capabilities [1]. Research occurs in 5 main Task Areas: Intelligence, Perception, Dexterous Manipulation and Unique Mobility (DMUM), Human Robot Interaction (HRI), and Integrated Research (IR). This last task of Integrated Research is especially critical and challenging. Individual research components can only be fully assessed when integrated onto a robot where they interact with other aspects of the system to create cross-Task capabilities which move beyond the State of the Art. Adding to the complexity, the RCTA is comprised of 12+ independent organizations across the United States. Each has its own constraints due to development environments, ITAR, "lab" vs "real-time" implementations, and legacy software investments from previous and ongoing programs. We have developed three main components to manage the Integration Task. The first is RFrame, a data-centric transport agnostic middleware which unifies the disparate environments, protocols, and data collection mechanisms. Second is the modular Intelligence Architecture built around the Common World Model (CWM). The CWM instantiates a Common Data Model and provides access services. Third is RIVET, an ITAR free Hardware-In-The-Loop simulator based on 3D game technology. RIVET provides each researcher a common test-bed for development prior to integration, and a regression test mechanism. Once components are integrated and verified, they are released back to the consortium to provide the RIVET baseline for further research. This approach allows Integration of new and legacy systems built upon different architectures, by application of Open Architecture principles.

  7. 10. VIEW TO NORTHEAST FROM WITHIN SOUTHWEST BAY, LOOKING THROUGH ...

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

    10. VIEW TO NORTHEAST FROM WITHIN SOUTHWEST BAY, LOOKING THROUGH CENTER BAY AND INTO NORTHEAST BAY. NOTE TRAVELING BRIDGE CRANE OVERHEAD AND SWINGING BOOM CRANES ATTACHED TO COLUMNS ON RIGHT AND LEFT. NOTE ALSO THE DIFFERENCE IN TRUSSES SUPPORTING CRANEWAY TRACKS FOR SIDE BAYS AND CENTER BAY. TRUSSES SUPPORTING CRANEWAY TRACKS IN SIDE BAYS (CENTER FOREGROUND AND FAR BACKGROUND) ARE HOWE TRUSSES WITH WOOD DIAGONALS AND STEEL VERTICALS. TRUSSES SUPPORTING CRANEWAY TRACKS IN CENTER BAY (MID BACKGROUND) ARE PRATT TRUSSES WITH WOOD VERTICALS AND DIAGONALS. - Rosie the Riveter National Historical Park, Auxiliary Plate Shop, 912 Harbour Way, Richmond, Contra Costa County, CA

  8. Column strength of tubes elastically restrained against rotation at the ends

    NASA Technical Reports Server (NTRS)

    Osgood, William R

    1938-01-01

    Report presents the results of a study made of the effects of known end restraint on commercially available round and streamline tubing of chromium-molybdenum steel, duralumin, stainless steel, and heat-treated chromium-molybdenum steel; and a more accurate method than any previously available, but still a practical method, was developed for designing compression members in riveted or welded structures, particularly aircraft. Two hundred specimens were tested as short, medium-length, and long columns with freely supported ends or elastically restrained ends. Tensile and compressive tests were made on each piece of original tubing from which column specimens were cut.

  9. Detailed finite element analysis and preliminary study of the effects of friction and fastener pre-tension on the mechanical behavior of fastened built-up members

    NASA Astrophysics Data System (ADS)

    Bonachera Martin, Francisco Javier

    The characterization of fatigue resistance is one of the main concerns in structural engineering, a concern that is particularly important in the evaluation of existing bridge members designed or erected before the development of fatigue design provisions. The ability of a structural member to develop alternate load paths after the failure of a component is known as member-level or internal redundancy. In fastened built-up members, these alternate load paths are affected by the combination of fastener pre-tension and friction between the structural member components in contact. In this study, a finite element methodology to model and analyze riveted and bolted built-up members was developed in ABAQUS and validated with experimental results. This methodology was used to created finite element models of three fastened plates subjected to tension, in which the middle plate had failed, in order to investigate the fundamental effects of combined fastener pre-tension and friction on their mechanical behavior. Detailed finite element models of riveted and bolted built-up flexural members were created and analyze to understand the effect of fastener pre-tension in member-level redundancy and resistance to fatigue and fracture. The obtained results showed that bolted members are able to re-distribute a larger portion of the load away from the failing component into the rest of the member than riveted members, and that this transfer of load also took place over a smaller length. Superior pre-tension of bolts, in comparison to rivets, results in larger frictional forces that develop at the contact interfaces between components and constitute additional alternate load paths that increase member-level redundancy which increase the fatigue and fracture resistance of the structural member during the failure of one of its components. Although fatigue and fracture potential may be mitigated by compressive stresses developing around the fastener hole due to fastener pre-tension, it

  10. Micromechanics of compression failures in open hole composite laminates

    NASA Technical Reports Server (NTRS)

    Guynn, E. Gail; Bradley, Walter L.

    1987-01-01

    The high strength-to-weight ratio of composite materials is ideally suited for aerospace applications where they already are used in commercial and military aircraft secondary structures and will soon be used for heavily loaded primary structures. One area impeding the widespread application of composites is their inherent weakness in compressive strength when compared to the tensile properties of the same material. Furthermore, these airframe designs typically contain many bolted or riveted joints, as well as electrical and hydraulic control lines. These applications produce areas of stress concentration, and thus, further complicate the compression failure problem. Open hole compression failures which represent a typical failure mode for composite materials are addressed.

  11. Deconstructing the skin: cytoarchitectural determinants of epidermal morphogenesis

    PubMed Central

    Simpson, Cory L.; Patel, Dipal M.; Green, Kathleen J.

    2012-01-01

    To provide a stable environmental barrier, the epidermis requires an integrated network of cytoskeletal elements and cellular junctions. Nevertheless, the epidermis ranks among the body’s most dynamic tissues, continually regenerating itself and responding to cutaneous insults. As keratinocytes journey from the basal compartment towards the cornified layers, they completely reorganize their adhesive junctions and cytoskeleton. These architectural components are more than just rivets and scaffolds — they are active participants in epidermal morphogenesis that regulate epidermal polarization, signalling and barrier formation. PMID:21860392

  12. Stresses In Vehicle Chassis Joints - A Canparison Of SPATE With Other Analysis Techniques

    NASA Astrophysics Data System (ADS)

    Loader, A. J.; Turner, W. B.; Harwood, N.

    1987-04-01

    Joints in ladder frame chassis have been studied as part of an SERC Teaching Company Schene. The joints between the cross members and side members are complex structures involving bolts, welds and/or rivets, as the cross member section can be tubular, box or C-section. It is therefore difficult to apply simple analytical methods to such joints. This paper compares the stresses obtained by brittle lacquer, strain gauge and SPATE measurements with those found from a finite elenent analysis of the joints.

  13. Imaging flaws in thin metal plates using a magneto-optic device

    NASA Technical Reports Server (NTRS)

    Wincheski, B.; Prabhu, D. R.; Namkung, M.; Birt, E. A.

    1992-01-01

    An account is given of the capabilities of the magnetooptic/eddy-current imager (MEI) apparatus in the case of aging aircraft structure-type flaws in 2024-T3 Al alloy plates. Attention is given to images of cyclically grown fatigue cracks from rivetted joints in fabricated lap-joint structures, electrical discharge machining notches, and corrosion spots. Although conventional eddy-current methods could have been used, the speed and ease of MEI's use in these tests is unmatched by such means. Results are displayed in real time as a test piece is scanned, furnishing easily interpreted flaw images.

  14. 19. VIEW TO SOUTHWEST OF FIRST FLOOR SHOWING CONVEYOR FOR ...

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

    19. VIEW TO SOUTHWEST OF FIRST FLOOR SHOWING CONVEYOR FOR MOVING MATERIAL TO SECOND FLOOR. (NOTE: THIS IS NOT AN ORIGINAL CONVEYOR FOR MOVING BODY PARTS) STAIRS IN BACKGROUND LEAD TO SECOND FLOOR VIA TOILET ROOM NO. 4 AND COAT ROOM AT MEZZANINES LEVEL SITUATED BETWEEN THE TWO SETS OF STAIRS. THERE ARE THREE OTHER TOILET/COAT ROOM MEZZANINES TO THE NORTH LOCATED ALONG THE WALL BETWEEN THE FIRST AND SECOND FLOORS, BEHIND AND TO THE LEFT OF THE STAIRS IS A FREIGHT ELEVATOR SHAFT. - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  15. 3M heavy duty roto peen: Baseline report; Summary

    SciTech Connect

    1997-07-31

    The roto peen scaler allows for the selective removal of concrete substrates. The peen is a tungsten carbide shot brazed to a hardened steel rivet that is supported by a heavy duty flexible flap. The peens are coupled with a commercially available piece of equipment that is used to scabble or remove the concrete. The scabbled debris is then collected into 55 gallon drums by means of a vacuum system. The safety and health evaluation during the human factors assessment focused on two main areas: noise and dust.

  16. Performance of the Spacelab Astro-1 mission heat pipe radiator

    NASA Technical Reports Server (NTRS)

    Humphries, W. R.; Hamner, R. M.; Stallings, R. D.; Cotton, J. A.

    1985-01-01

    This paper describes the design and performance of the Astro Integrated Radiator System (IRS). The system was recently ground tested and proven successful in rejecting approximately 400 watts of heat. The radiator was constructed from an aluminum panel configured to form two orthogonal planes. Heat pipes were adhesively bonded and riveted to the radiator to isothermalize the surface. The IRS was subjected to a full thermal vacuum test to validate the thermal math model and to qualify the radiator for space flight. The thermal performance met prescribed temperature limits with margins at both extremes, and no mechanical failures occurred.

  17. Stresses Around Rectangular Cut-outs with Reinforced Coaming Stringers

    NASA Technical Reports Server (NTRS)

    Kuhn, Paul; Rafel, Norman; Griffith, George E

    1947-01-01

    Strain measurements and strength tests were made on six skin-stringer panels under axial load. Three of these panels had short rectangular cut-outs, and three a long one. The width of the cut-out was about one-half of the width of the panel. Three types of coating stringers were used: without reinforcement, with riveted-up reinforcement, or with integral reinforcement. The strain measurements were found to be in good agreement with a previously published theory adapted where necessary by making overlapping assumptions.

  18. Fastener Design Manual

    NASA Technical Reports Server (NTRS)

    Barrett, Richard T.

    1990-01-01

    This manual was written for design engineers to enable them to choose appropriate fasteners for their designs. Subject matter includes fastener material selection, platings, lubricants, corrosion, locking methods, washers, inserts, thread types and classes, fatigue loading, and fastener torque. A section on design criteria covers the derivation of torque formulas, loads on a fastener group, combining simultaneous shear and tension loads, pullout load for tapped holes, grip length, head styles, and fastener strengths. The second half of this manual presents general guidelines and selection criteria for rivets and lockbolts.

  19. Recent fracture mechanics results from NASA research related to the aging commercial transport fleet

    NASA Technical Reports Server (NTRS)

    Harris, Charles E.

    1991-01-01

    NASA is conducting the Airframe Structural Integrity Program in support of the aging commercial transport fleet. This interdisciplinary program is being worked in cooperation with the U.S. airframe manufacturers, airline operators, and the FAA. Advanced analysis methods are under development to predict the fatigue crack growth in complex built-up shell structures. Innovative nondestructive examination technologies are also under development to provide large area inspection capability to detect corrosion, disbonds, and fatigue cracks. Recent fracture mechanics results applicable to predicting the growth of cracks initiating at the rivets of fuselage splice joints are reviewed.

  20. Fracture mechanics research at NASA related to the aging commercial transport fleet

    NASA Technical Reports Server (NTRS)

    Newman, James C., Jr.; Harris, Charles E.

    1992-01-01

    NASA is conducting the Airframe Structural Integrity Program in support of the aging commercial transport fleet. This interdisciplinary program is being worked in cooperation with the U.S. airframe manufacturers, airline operators, and the FAA. Advanced analysis methods are under development and an extensive testing program is under way to study fatigue crack growth and fracture in complex built-up shell structures. Innovative nondestructive examination technologies are also being developed to provide large area inspection capability to detect corrosion, disbonds, and cracks. Recent fracture mechanics results applicable to predicting the growth of cracks under monotonic and cyclic loading at rivets in fuselage lap-splice joints are reviewed.

  1. Triton 2 (1B)

    NASA Technical Reports Server (NTRS)

    Clark, Michelle L.; Meiss, A. G.; Neher, Jason R.; Rudolph, Richard H.

    1994-01-01

    The goal of this project was to perform a detailed design analysis on a conceptually designed preliminary flight trainer. The Triton 2 (1B) must meet the current regulations in FAR Part 23. The detailed design process included the tasks of sizing load carrying members, pulleys, bolts, rivets, and fuselage skin for the safety cage, empennage, and control systems. In addition to the regulations in FAR Part 23, the detail design had to meet established minimums for environmental operating conditions and material corrosion resistance.

  2. Inspecting for widespread fatigue damage: Is partial debonding the key?

    NASA Technical Reports Server (NTRS)

    Brewer, John

    1994-01-01

    Experimental and analytical results indicate that cracks can initiate, grow, and coalesce more rapidly in fuselage lap joints that have experienced partial or complete debonding. Computational analysis in this paper shows that stress concentrations and stress intensity factors at the rivet holes are far less severe when the bond is intact. Debonding hastens the initiation of widespread fatigue cracks and significantly increases crack growth rate. Thus, debonded regions serve as "breeding grounds" for widespread fatigue damage. Therefore, the effectiveness of lap joint inspection programs may be enhanced if detailed inspections are focused on areas in which debonding has been detected.

  3. [State of vegetative regulation in workers exposed to vibration at work during industrial implementation of hi-tech pneumoinstruments].

    PubMed

    Drobyshev, V A; Shpagina, L A; Panacheva, L A; Gerasimenko, O N; Abramovich, S G; Smirnova, I N

    2016-01-01

    The study was conducted on aircraft-building enterprise during production microcycle (before working shift start, during last working hour and in an hour after the shift end)--spectral analysis covered variability of heart rhythm in 70 male assembler riveters aged 25-59, divided into 2 groups in accordance with industrial equipment used. The group 1 used standard vibroinstrument, the group 2--pneumoinstruments with low vibration velocity parameters. Triple study during the working shift revealed in group 2 an adequate reaction of vegetative nervous system to vibration, in group 1 a negative trend was seen with centralization of regulatory processes and absence of adequate recovery in an hour after work.

  4. Laser ablation of CFRP using picosecond laser pulses at different wavelengths from UV to IR

    NASA Astrophysics Data System (ADS)

    Wolynski, Alexander; Herrmann, Thomas; Mucha, Patrick; Haloui, Hatim; L'huillier, Johannes

    Laser processing of carbon fibre reinforced plastics (CFRP) has a great industrial relevance for high performance structural parts in airplanes, machine tools and cars. Through-holes drilled by nanosecond laser pulses show thermal induced molten layers and voids. Recently, picosecond lasers have demonstrated the ability to drill high-efficient and high-quality rivet through-holes. In this paper a high-power picosecond laser system operating at different wavelengths (355 nm, 532 nm and 1064 nm) has been used for CFRP ablation experiments to study the influence of different laser parameters in terms of machining quality and processing time.

  5. 3M heavy duty roto peen: Baseline report; Greenbook (chapter)

    SciTech Connect

    1997-07-31

    The heavy-duty roto peen technology is being evaluated at Florida International University (FIU) as a baseline technology. It is a commercially available technology and has been used for various projects at locations throughout the country. In conjunction with FIU`s evaluation of efficiency and cost, this report covers the human factors assessment for safety and health issues. The heavy-duty roto peen allows for the selective removal of concrete substrates. The peen is a tungsten carbide shot brazed to a hardened steel rivet that is supported by a heavy-duty flexible flap. The shot rivet is kept captive to the tool by mounting the roto peen in a slotted hub. The heavy-duty roto peen is designed to be used with several commercially available pieces of equipment. The equipment being used will determine the width of each pass. The equipment being used with the roto peen is then connected to a vacuum system for dust collection during scabbling. The safety and health evaluation during the human factors assessment focused on two main areas: noise and dust.

  6. 3M heavy duty roto peen: Baseline report

    SciTech Connect

    1997-07-31

    The heavy-duty roto peen technology was being evaluated at Florida International University (FIU) as a baseline technology. It is a commercially available technology and has been used for various projects at locations throughout the country. In conjunction with FIU`s evaluation of efficiency and cost, this report covers the human factors assessment for safety and health issues. The heavy-duty roto peen allows for the selective removal of concrete substrates. The peen is a tungsten carbide shot brazed to a hardened steel rivet that is supported by a heavy-duty flexible flap. The shot rivet is kept captive to the tool by mounting the roto peen in a slotted hub. The heavy-duty roto peen is designed to be used with several commercially available pieces of equipment. The equipment being used will determine the width of each pass. The equipment being used with the roto peen is then connected to a vacuum system for dust collection during scabbling. The safety and health evaluation during the human factors assessment focused on two main areas: noise and dust.

  7. Fracture Analysis of the FAA/NASA Wide Stiffened Panels

    NASA Technical Reports Server (NTRS)

    Seshadri, B. R.; Newman, J. C., Jr.; Dawicke, D. S.; Young, R. D.

    1998-01-01

    This paper presents the fracture analyses conducted on the FAA/NASA stiffened and unstiffened panels using the STAGS (STructural Analysis of General Shells) code with the critical crack-tip-opening angle (CTOA) fracture criterion. The STAGS code with the "plane-strain" core option was used in all analyses. Previous analyses of wide, flat panels have shown that the high-constraint conditions around a crack front, like plane strain, has to be modeled in order for the critical CTOA fracture criterion to predict wide panel failures from small laboratory tests. In the present study, the critical CTOA value was determined from a wide (unstiffened) panel with anti-buckling guides. The plane-strain core size was estimated from previous fracture analyses and was equal to about the sheet thickness. Rivet flexibility and stiffener failure was based on methods and criteria, like that currently used in industry. STAGS and the CTOA criterion were used to predict load-against-crack extension for the wide panels with a single crack and multiple-site damage cracking at many adjacent rivet holes. Analyses were able to predict stable crack growth and residual strength with a few percent (5%) of stiffened panel tests results but over predicted the buckling failure load on a unstiffened panel with a single crack by 10%.

  8. Impact resistance of spar-shell composite fan blades

    NASA Technical Reports Server (NTRS)

    Graff, J.; Stoltze, L.; Varholak, E. M.

    1973-01-01

    Composite spar-shell fan blades for a 1.83 meter (6 feet) diameter fan stage were fabricated and tested in a whirling arm facility to evaluate foreign object damage (FOD) resistance. The blades were made by adhesively bonding boron-epoxy shells on titanium spars and then adhesively bonding an Inconel 625 sheath on the leading edge. The rotating blades were individually tested at a tip speed of 800 feet per second. Impacting media used were gravel, rivets, bolt, nut, ice balls, simulated birds, and a real bird. Incidence angles were typical of those which might be experienced by STOL aircraft. The tests showed that blades of the design tested in this program have satisfactory impact resistance to small objects such as gravel, rivets, nuts, bolts, and two inch diameter ice balls. The blades suffered nominal damage when impacted with one-pound birds (9 to 10 ounce slice size). However, the shell was removed from the spar for a larger slice size.

  9. Screening of In Vivo Activated Genes in Enterococcus faecalis during Insect and Mouse Infections and Growth in Urine

    PubMed Central

    Hanin, Aurelie; Sava, Irina; Bao, YinYin; Huebner, Johannes; Hartke, Axel; Auffray, Yanick; Sauvageot, Nicolas

    2010-01-01

    Enterococcus faecalis is part of the commensal microbiota of humans and its main habitat is the gastrointestinal tract. Although harmless in healthy individuals, E. faecalis has emerged as a major cause of nosocomial infections. In order to better understand the transformation of a harmless commensal into a life-threatening pathogen, we developed a Recombination-based In Vivo Expression Technology for E. faecalis. Two R-IVET systems with different levels of sensitivity have been constructed in a E. faecalis V583 derivative strain and tested in the insect model Galleria mellonella, during growth in urine, in a mouse bacteremia and in a mouse peritonitis model. Our combined results led to the identification of 81 in vivo activated genes. Among them, the ef_3196/7 operon was shown to be strongly induced in the insect host model. Deletion of this operonic structure demonstrated that this two-component system was essential to the E. faecalis pathogenic potential in Galleria. Gene ef_0377, induced in insect and mammalian models, has also been further analyzed and it has been demonstrated that this ankyrin-encoding gene was also involved in E. faecalis virulence. Thus these R-IVET screenings led to the identification of new E. faecalis factors implied in in vivo persistence and pathogenic potential of this opportunistic pathogen. PMID:20686694

  10. Consequences of disrupting Salmonella AI-2 signaling on interactions within soft rots.

    PubMed

    Cox, Clayton E; McClelland, Michael; Teplitski, Max

    2013-04-01

    Within soft rots, Salmonella spp. reach population densities 10- to 100-fold higher than within intact plants. The hypothesis that Salmonella spp. exchange AI-2 signals with Pectobacterium carotovorum to increase its competitive fitness was tested using mutants involved in AI-2 production (luxS) or perception (lsrACDBF or lsrG). Co-infections of a wild-type Salmonella sp. and its AI-2 mutants (at ≈3 to 10(4)) were established in green or red tomato ('FL 47' or 'Campari' for 3 or 5 days) as well as tomato co-infected with Pectobacterium (at 10(9)) or its luxS mutant. There were no significant differences in the competitive fitness of Salmonella, indicating that AI-2 signaling is not a major input in the interactions between these organisms under the tested conditions. A Salmonella lsrG::tnpR-lacZ resolvase in vivo expression technology (RIVET) reporter, constructed to monitor AI-2-related gene expression, responded strongly to the luxS deletion but only weakly to external sources of AI-2. Growth in soft rots generally decreased RIVET resolution; however, the effect was not correlated to the luxS genotype of the Pectobacterium sp. The results of this study show that AI-2 signaling offers no significant benefit to Salmonella spp. in this model of colonization of tomato or soft rots. PMID:23324045

  11. Fracture Analysis of the FAA/NASA Wide Stiffened Panels

    NASA Technical Reports Server (NTRS)

    Seshadri, B. R.; Newman, J. C., Jr.; Dawicke, D. S.; Young, R. D.

    1999-01-01

    This paper presents the fracture analyses conducted on the FAA/NASA stiffened and unstiffened panels using the STAGS (STructural Analysis of General Shells) code with the critical crack-tip-opening angle (CTOA) fracture criterion. The STAGS code with the "plane-strain" core option was used in all analyses. Previous analyses of wide, flat panels have shown that the high-constraint conditions around a crack front, like plane strain, has to be modeled in order for the critical CTOA fracture criterion to predict wide panel failures from small laboratory tests. In the present study, the critical CTOA value was determined from a wide (unstiffened) panel with anti-buckling guides. The plane-strain core size was estimated from previous fracture analyses and was equal to about the sheet thickness. Rivet flexibility and stiffener failure was based on methods and criteria, like that currently used in industry. STAGS and the CTOA criterion were used to predict load-against-crack extension for the wide panels with a single crack and multiple-site damage cracking at many adjacent rivet holes. Analyses were able to predict stable crack growth and residual strength within a few percent (5%) of stiffened panel tests results but over predicted the buckling failure load on an unstiffened panel with a single crack by 10%.

  12. Design, fabrication, installation and flight service evaluation of a composite cargo ramp skin on a model CH-53 helicopter

    NASA Technical Reports Server (NTRS)

    Lowry, D. W.; Rich, M. J.

    1983-01-01

    The installation of a composite skin panel on the cargo ramp of a CH-530 marine helicopter is discussed. The composite material is of Kevlar/Epoxy (K/E) which replaces aluminum outer skins on the aft two bays of the ramp. The cargo ramp aft region was selected as being a helicopter airframe surface subjected to possible significant field damage and would permit an evaluation of the long term durability of the composite skin panel. A structural analysis was performed and the skin shears determined. Single lap joints of K/E riveted to aluminum were statically tested. The joint tests were used to determine bearing allowables and the required K/E skin gage. The K/E skin panels riveted to aluminum edge members were tested in a shear fixture to confirm the allowable shear and bearing strengths. Impact tests were conducted on aluminum skin panels to determine energy level and damage relationship. The K/E skin panels of various ply orientations and laminate thicknesses were then impacted at similar energy levels. The results of the analysis and tests were used to determine the required K/E skin gages in each of the end two bays of the ramp.

  13. Stress concentrations for straight-shank and countersunk holes in plates subjected to tension, bending, and pin loading

    NASA Technical Reports Server (NTRS)

    Shivakumar, K. N.; Newman, J. C., Jr.

    1992-01-01

    A three dimensional stress concentration analysis was conducted on straight shank and countersunk (rivet) holes in a large plate subjected to various loading conditions. Three dimensional finite element analysis were performed with 20 node isoparametric elements. The plate material was assumed to be linear elastic and isotropic, with a Poisson ratio of 0.3. Stress concentration along the bore of the hole were computed for several ratios of hole radius to plate thickness (0.1 to 2.5) and ratios of countersink depth to plate thickness (0.25 to 1). The countersink angles were varied from 80 to 100 degrees in some typical cases, but the angle was held constant at 100 degrees for most cases. For straight shank holes, three types of loading were considered: remote tension, remote bending, and wedge loading in the hole. Results for remote tension and wedge loading were used to estimate stress concentration for simulated rivet in pin loading. For countersunk holes only remote tension and bending were considered. Based on the finite element results, stress concentration equations were developed. Whenever possible, the present results were compared with other numerical solutions and experimental results from the literature.

  14. Factors Associated With Non-compliance of Asbestos Occupational Standards in Brake Repair Workers.

    PubMed

    Cely-García, María Fernanda; Curriero, Frank C; Giraldo, Margarita; Méndez, Lorena; Breysse, Patrick N; Durán, Mauricio; Torres-Duque, Carlos A; González-García, Mauricio; Pérez, Carolina; Parada, Patricia; Ramos-Bonilla, Juan Pablo

    2016-10-01

    Asbestos and non-asbestos containing brake products are currently used in low- and middle-income countries like Colombia. Because brake products are distributed detached from their supports, they require manipulation before installation, which release fibers and expose workers. Previous studies of our research group have documented exposures in excess of the widely accepted 0.1 f/cm(3) exposure guideline. The aim of this study is to identify factors associated with non-compliance of the 8-h time weighted average (TWA) 0.1 f/cm(3) asbestos occupational limit among brake mechanics (i.e. riveters). Eighteen brake repair shops (BRS) located in Bogotá (Colombia) were sampled during 3 to 6 consecutive days for the entire work-shift. Personal and short-term personal samples were collected following NIOSH methods 7400 and 7402. Longitudinal based logistic regression models were used to determine the association between the odds of exceeding the 8-h TWA 0.1 f/cm(3) asbestos occupational limit and variables such as type of tasks performed by workers, workload (number of products manipulated daily), years of experience as riveters, and shop characteristics. These models can be used to estimate the odds of being currently or historically overexposed when sampling data do not exist. Since the information required to run the models can vary for both retrospective and current asbestos occupational exposure studies, three models were constructed with different information requirements. The first model evaluated the association between the odds of non-compliance with variables related to the workload, the second model evaluated the association between the odds of non-compliance with variables related to the manipulation tasks, and the third model evaluated the association between the odds of non-compliance with variables related with both the type of tasks performed by workers and the workload. Variables associated with the odds of non-compliance included conducting at least one

  15. Thermographic detection of cracks in thin sheets

    NASA Technical Reports Server (NTRS)

    Cramer, K. E.; Syed, Hazari; Winfree, William P.

    1991-01-01

    A thermographic inspection technique for crack detection based on a 2D filter convolved with the thermal temperature images is presented. The filter is designed to approximate operating on the temperature images with a Laplacian operator. This operation yields an image which approximates changes in the heat flux in a thin plate. This filtering method results in an enhanced contrast due to the presence of cracks. Measurements have been performed on samples with fabricated electrical discharge machining (EDM) notches (both through-the-thickness and surface notches) and closed fatigue cracks around rivets. It is shown that the technique is effective for the detection of various crack lengths down to the resolution limits of the imager used.

  16. Inspection of a Medieval Wood Sculpture Using Computer Tomography

    NASA Astrophysics Data System (ADS)

    Kapitany, K.; Somogyi, A.; Barsi, A.

    2016-06-01

    Computer tomography (CT) is an excellent technique for obtaining accurate 3D information about the human body. It allows to visualize the organs, bones and blood vessels, furthermore it enables to diagnose anomalies and diseases. Its spatial reconstruction capability supports other interesting applications, such as inspecting different, even valuable objects like ancient sculptures. Current paper presents a methodology of evaluating CT and video imagery through the example of investigating a wood Madonna with infant Jesus sculpture from the 14th century. The developed techniques extract the outer boundary of the statue, which has been triangulated to derive the surface model. The interior of the sculpture has also been revealed: the iron bolts and rivets as well as the woodworm holes can be mapped. By merging the interior and outer data (geometry and texture) interesting visualizations (perspective views, sections etc.) have been created.

  17. Thermal performance evaluation of the Suncatcher SH-11 (liquid) solar collector

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The procedures used and the results obtained during the evaluation test program on the Solar Unlimited, Inc., Suncatcher SH-11 (liquid) solar collector are presented. The flat-plate collector case assembly is made of .08 inch aluminum 3003 H14 riveted with fiberglass board insulation. The absorber consists of collared aluminum fins mechanically bonded to 3/8 inch copper tubing and coated with 3M Nextel black. Water is used as the working fluid. The glazing is made of a single glass, 1/8 inch water white, tempered and antireflective. The collector weight is 85 pounds with overall external dimensions of about 35.4 in x 82.0 in x 4.0 in. Thermal performance data on the Solar Unlimited Suncatcher SH-11 solar collector under simulated conditions were conducted using the MSFC Solar Simulator.

  18. Drawn arc stud welding: Crossing over from steel to aluminum

    SciTech Connect

    Ramasamy, S.

    2000-01-01

    In their quest to reduce vehicle weights, car manufacturers are exploring further use of aluminum, including more aluminum components in body construction. To acquire a better understanding of aluminum stud welding, auto manufacturers worldwide have formed a task force to conduct research on aluminum joining methods. Currently, Emhart Fastening Teknologies is working with this group in development programs such as Earthing studs, WELDFAST and Self-Pierce Rivet (SPR). The global automotive industry is clearly committed to the increased use of aluminum in cars and trucks. This presents enormous challenges and responsibilities for assembly systems suppliers, particularly those specializing in welding processes. Continuing strides in the technological sophistication of DASW is bringing this process to the forefront in advancing the use of aluminum in vehicles throughout the world.

  19. [State of vegetative regulation in workers exposed to vibration at work during industrial implementation of hi-tech pneumoinstruments].

    PubMed

    Drobyshev, V A; Shpagina, L A; Panacheva, L A; Gerasimenko, O N; Abramovich, S G; Smirnova, I N

    2016-01-01

    The study was conducted on aircraft-building enterprise during production microcycle (before working shift start, during last working hour and in an hour after the shift end)--spectral analysis covered variability of heart rhythm in 70 male assembler riveters aged 25-59, divided into 2 groups in accordance with industrial equipment used. The group 1 used standard vibroinstrument, the group 2--pneumoinstruments with low vibration velocity parameters. Triple study during the working shift revealed in group 2 an adequate reaction of vegetative nervous system to vibration, in group 1 a negative trend was seen with centralization of regulatory processes and absence of adequate recovery in an hour after work. PMID:27164752

  20. 18. VIEW SOUTHWEST OF 450 HP TURBINE INSTALLATION IN BASEMENT ...

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

    18. VIEW SOUTHWEST OF 450 HP TURBINE INSTALLATION IN BASEMENT OF GRANITEVILLE MILL. MAIN FEATURE OF THE PHOTOGRAPH IS THE PENSTOCK CONDUCTING WATER TO THE TURBINE IN THE BACKGROUND. THE PENSTOCK IS OF RIVETED IRON CONSTRUCTION AND REPLACED A WOOD PENSTOCK IN 1882. THE COVERED OPENING IN THE CENTER OF THE PHOTOGRAPH ORIGINALLY CONNECTED TO A STANDPIPE WHICH EXITED VERTICALLY THROUGH THE MILL. THE STANDPIPE MODERATED WATER PRESSURE AND SERVED AS A SAFETY FEATURE IN THE EVENT THE TURBINE GATES WERE RAPIDLY CLOSED. (IF LOAD IN THE MILL WERE SUDDENLY STOPPED-SAY AT QUITTING TIME-THE GATES WOULD SHUT DOWN FLOW TO THE TURBINE. THE STANDPIPE OFFERED A PLACE FOR THE WATER, RAPIDLY MOVING THROUGH THE PENSTOCK, TO ESCAPE. IN A SHUT-DOWN SITUATION WATER WOULD ... - Graniteville Mill, Marshall Street, Graniteville, Aiken County, SC

  1. Low-frequency nondestructive analysis of cracks in multilayer structures using a scanning magnetic microscope

    NASA Astrophysics Data System (ADS)

    Adamo, M.; Nappi, C.; Sarnelli, E.

    2010-09-01

    The use of a scanning magnetic microscope (SMM) with a high temperature superconducting quantum interference device (SQUID) for quantitative measurements in eddy current nondestructive analysis (NDA) is presented. The SQUID has been used to detect the weak magnetic field variations around a small defect, close to a structural part generating an intensive magnetic field. The experimental data for a deep crack close to a rivet in a multilayer conducting plate have been taken in a RF-shielded environment and discussed in the light of the theoretical predictions. The results show that eddy current NDA can distinguish subsurface crack signals from wider structural signals, with defects located 10 mm below the surface. Moreover, in order to visualize the structure of the probing current when a circular induction coil is used, the simulation of eddy currents in a thick unflawed conducting plate has been carried out.

  2. Low Temperature SQUID for NDE Applications

    NASA Technical Reports Server (NTRS)

    Wincheski, Buzz (Technical Monitor); Selim, Raouf

    2003-01-01

    We have developed a low temperature SuperConducting Quantum Interference Device - SQUID measurement system for detection of defects deep under the surface of aluminum structures using eddy current techniques. The system uses a two dimensional planar inducer with two different excitation frequencies to induce a current in the sample. We have developed a data analysis software program that enabled us to distinguish between round defects (holes), straight defects (slots) and slots close to holes simulating cracks starting from rivets in aluminum structures. We were able to detect defects that are 8mm below the surface. We have also measured the change in phase of the detected signal as a function of depth of the defect. This relationship can be used to determine the depth of hidden flaws. Using this analysis software with the high temperature SQUID system at NASA Langley we were able to detect slots close to holes in layered aluminum sample.

  3. Spurious signals generated by electron tunneling on large reflector antennas

    NASA Technical Reports Server (NTRS)

    Higa, W. H.

    1975-01-01

    Large reflector antennas are currently fabricated by assembling a large number of small light aluminum panels onto a superstructure. A large number of aluminum-to-aluminum joints are inherently exposed to RF radiation on such an antenna. It is shown in this paper that the natural oxide layer on aluminum is of the correct thickness to permit electron tunneling through the Al-Al2O3-Al junctions. The nonlinearity due to the junctions then generates spurious signals when these antennas are used for simultaneous transmission and reception of signals at different frequencies. Moreover, the large number of junctions (rivets) on an antenna can combine to produce serious interference in these diplexed systems.

  4. 20. 'Erection Plan, Renewal of Bridge 210 C over Sacramento ...

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

    20. 'Erection Plan, Renewal of Bridge 210 C over Sacramento River near Tehama, Calif., 3 140'-0' S. T. Riveted Thru Truss Spans, 17'-9' C. to C. Trusses, 31'-0' C. To C. Chords. U.S.S. P. Co. Pacific Coast Dept., Order No. SF 604, Southern Pacific Co., Order No. 51168-P-38428, 1925 Specifications, Scale in. ft., American Bridge Co., Ambridge Plant, Dwgs. made at Ambridge No. 5 in charge of Reehl, Detailed by W.F.R., Date, Checked by L.A.E., Date 1/5/29, Fld. conn. chk. by ENN, Date 3/9/29, Order No. F5659, Sheet No. E3.' - Southern Pacific Railroad Shasta Route, Bridge No. 210.52, Milepost 210.52, Tehama, Tehama County, CA

  5. Migrants, Manpower and Math in the Coming Europe

    PubMed Central

    Evans, Robert G.

    2015-01-01

    “A dead child” said Stalin “is a tragedy. Two million are a statistic.” A single photograph of a beach riveted world attention, converting Syrian refugees from statistics to tragedy. But the statistics remain. Three Canadian columnists have offered contrasting interpretations. Eric Reguly argues that a static and aging Europe needs more manpower to sustain its economy. Margaret Wente, however, observes the failure of integration of migrants in Sweden. Migrants are drawn by open borders and a generous welfare state, but do not fit an advanced, high-skill economy. Gwynne Dyer notes that current inflows, IF evenly distributed, are a tiny proportion of the overall European Union. But economic migrants from Africa are a much larger issue. Their numbers are effectively inexhaustible. PMID:26742112

  6. The effect of oblique angle of sound incidence, realistic edge conditions, curvature and in-plane panel stresses on the noise reduction characteristics of general aviation type panels

    NASA Technical Reports Server (NTRS)

    Grosveld, F.; Lameris, J.; Dunn, D.

    1979-01-01

    Experiments and a theoretical analysis were conducted to predict the noise reduction of inclined and curved panels. These predictions are compared to the experimental results with reasonable agreement between theory and experiment for panels under an oblique angle of sound incidence. Theoretical as well as experimental results indicate a big increase in noise reduction when a flat test panel is curved. Further curving the panel slightly decreases the noise reduction. Riveted flat panels are shown to give a higher noise reduction in the stiffness-controlled frequency region, while bonded panels are superior in this region when the test panel is curved. Experimentally measured noise reduction characteristics of flat aluminum panels with uniaxial in-plane stresses are presented and discussed. These test results indicate an important improvement in the noise reduction of these panels in the frequency range below the fundamental panel/cavity frequency.

  7. NASTRAN DMAP Fuzzy Structures Analysis: Summary of Research

    NASA Technical Reports Server (NTRS)

    Sparrow, Victor W.

    2001-01-01

    The main proposed tasks of Cooperative Agreement NCC1-382 were: (1) developing MSC/NASTRAN DMAP language scripts to implement the Soize fuzzy structures approach for modeling the dynamics of complex structures; (2) benchmarking the results of the new code to those for a cantilevered beam in the literature; and (3) testing and validating the new code by comparing the fuzzy structures results to NASA Langley experimental and conventional finite element results for two model test structures representative of aircraft fuselage sidewall construction: (A) a small aluminum test panel (SLP, single longeron panel) with a single longitudinal stringer attached with bolts; and (B) a 47 by 72 inch flat aluminum fuselage panel (AFP, aluminum fuselage panel) including six longitudinal stringers and four frame stiffeners attached with rivets.

  8. In the path of destruction - eyewitness chronicles of Mount St. Helens

    USGS Publications Warehouse

    Waitt, Richard B.

    2015-01-01

    “The air had no oxygen, like being trapped underwater…I was being cremated, the pain unbearable.”-- Jim Scymanky“I was on my knees, my back to the hot wind. It blew me along, lifting my rear so I was up on my hands…It was hot but I didn’t feel burned—until I felt my ears curl.”—Mike HubbardA napping volcano blinked awake in March 1980. Two months later, the mountain roared. Author Richard Waitt was one of the first to arrive following the mountain’s early rumblings. A geologist with intimate knowledge of Mount St. Helens, Waitt delivers a detailed and accurate chronicle of events. The eruption story unfolds through unforgettable, riveting narratives—the heart of a masterful chronology that also delivers engrossing science, history, and journalism.

  9. Low-Temperature Forming of Beta Titanium Alloys

    NASA Technical Reports Server (NTRS)

    Kaneko, R. S.; Woods, C. A.

    1983-01-01

    Low cost methods for titanium structural fabrication using advanced cold-formable beta alloys were investigated for application in a Mach 2.7 supersonic cruise vehicle. This work focuses on improving processing and structural efficiencies as compared with standard hot formed and riveted construction of alpha-beta alloy sheet structure. Mechanical property data and manufacturing parameters were developed for cold forming, brazing, welding, and processing Ti-15V-3Cr-3Sn-3Al sheet, and Ti-3Al-8V-6Cr-4Zr on a more limited basis. Cost and structural benefits were assessed through the fabrication and evaluation of large structural panels. The feasibility of increasing structural efficiency of beta titanium structure by selective reinforcement with metal matrix composite was also explored.

  10. Low cost fabrication of sheet structure using a new beta titanium alloy, Ti-15V-3Cr-3Al-3Sn

    NASA Technical Reports Server (NTRS)

    Kaneko, R. S.; Davis, G. W.; Woods, C. A.; Royster, D. M.

    1982-01-01

    Development efforts have been undertaken to improve the processing and structural efficiencies of advanced cold-formable beta Ti alloys, using the standard, hot-formed and rivetted construction of Ti-6Al-4V sheet structures as a basis for comparison. Ti-15V-3Cr-3Al-3Sn (Ti-15-3) beta alloy is formable, brazable and weldable in the solution-treated condition, and after aging displays mechanical properties suitable for postulated service in the -65 to 600 F temperature range. A novel methodology using cold-formed Ti-15-3 stringers and Ti-6Al-4V face sheets that are joined by means of an out-of-furnace isothermal brazing process, followed by low temperature aging, can reduce production costs by as much as 28 per cent. Structural efficiency has been demonstrated in room and elevated temperature crippling tests of small skin-stringer assemblies.

  11. The Neptune System in Voyager's Afterglow.

    PubMed

    Kerr, R A

    1989-09-29

    Any time the view of a planet leaps from a fuzzy dot accompanied by two pinpoints of light to the riveting details of swirling clouds, rings, cratered moonlets, and even individual dust particles, planetary science is going to be in for some upheaval. Voyager 2's encounter with Neptune was no exception. Something as seemingly innocuous as an hour or two shift in the new length of a Neptunian day is giving meteorologists and physicists fits. And Neptune's canted, complex magnetic field found by Voyager knocks into a cocked hat most ideas about why a similar field at Uranus was unique. But there were more reassuring discoveries as well. Here are samplings of both sorts of findings.

  12. Study of the damping characteristics of general aviation aircraft panels and development of computer programs to calculate the effectiveness of interior noise control treatment, part 1

    NASA Technical Reports Server (NTRS)

    Navaneethan, R.; Hunt, J.; Quayle, B.

    1982-01-01

    Tests were carried out on 20 inch x 20 inch panels at different test conditions using free-free panels, clamped panels, and panels as installed in the KU-FRL acoustic test facility. Tests with free-free panels verified the basic equipment set-up and test procedure. They also provided a basis for comparison. The results indicate that the effect of installed panels is to increase the damping ratio at the same frequency. However, a direct comparison is not possible, as the fundamental frequency of a free-free panel differs from the resonance frequency of the panel when installed. The damping values of panels installed in the test facility are closer to the damping values obtained with fixed-fixed panels. Effects of damping tape, stiffeners, and bonded and riveted edged conditions were also investigated. Progress in the development of a simple interior noise level control program is reported.

  13. Measurements of fuselage skin strains and displacements near a longitudinal lap joint in a pressurized aircraft

    NASA Technical Reports Server (NTRS)

    Phillips, Edward P.; Britt, Vicki O.

    1991-01-01

    Strains and displacements in a small area near a longitudinal lap joint in the fuselage skin of a B737 aircraft were measured during a pressurization cycle to a differential pressure of 6.2 psi while the aircraft was on the ground. It was found that hoop strains were higher than longitudinal strains at each location; membrane strains in the unreinforced skin were higher than in the joint; membrane strains in the hoop direction, as well as radial displacements, tended to be highest at the mid-bay location between skin reinforcements; significant bending in the hoop direction occurred in the joint and in the skin near the joint, and the bending was unsymmetrically distributed about the stringer at the middle of the joint; and radial displacements were unsymmetrically distributed across the lap joint. The interpretation of the strain gage data for locations on the bonded and riveted lap joint assumed that the joint did not contain disbonded areas.

  14. Narrating September 11: Race, Gender, and the Play of Cultural Identities

    PubMed Central

    Mattingly, Cheryl; Lawlor, Mary; Jacobs-Huey, Lanita

    2010-01-01

    This article considers the September 11 tragedy as an event that has created a powerful experience—an astonishing and unthinkable “breach” from the expected and routine—that has riveted the American public and provoked personal storytelling. September 11 and its aftermath have provided an occasion for rethinking and reworking cultural identity. We explore how September 11 and subsequent events have been experienced, constructed, and narrated by African American women, primarily from working-class and low-income backgrounds. These stories, and the commentaries and discussions that surround them, provide vehicles for these women to ponder what sort of social contexts they inhabit, within what sort of subject positions they are placed, and how these may be shifting in light of the attacks and America's “War on Terrorism. PMID:20706602

  15. Characterization of Nitinol Laser-Weld Joints by Nondestructive Testing

    NASA Astrophysics Data System (ADS)

    Wohlschlögel, Markus; Gläßel, Gunter; Sanchez, Daniela; Schüßler, Andreas; Dillenz, Alexander; Saal, David; Mayr, Peter

    2015-12-01

    Joining technology is an integral part of today's Nitinol medical device manufacturing. Besides crimping and riveting, laser welding is often applied to join components made from Nitinol to Nitinol, as well as Nitinol components to dissimilar materials. Other Nitinol joining techniques include adhesive bonding, soldering, and brazing. Typically, the performance of joints is assessed by destructive mechanical testing, on a process validation base. In this study, a nondestructive testing method—photothermal radiometry—is applied to characterize small Nitinol laser-weld joints used to connect two wire ends via a sleeve. Two different wire diameters are investigated. Effective joint connection cross sections are visualized using metallography techniques. Results of the nondestructive testing are correlated to data from destructive torsion testing, where the maximum torque at fracture is evaluated for the same joints and criteria for the differentiation of good and poor laser-welding quality by nondestructive testing are established.

  16. An investigation of the aerodynamic characteristics of a new general aviation airfoil in flight

    NASA Technical Reports Server (NTRS)

    Gregorek, G. M.; Hoffmann, M. J.; Weislogel, G. S.

    1982-01-01

    A low speed airfoil, the GA(W)-2, - a 13% thickness to chord ratio airfoil was evaluated. The wing of a Beech Sundowner was modified at by adding balsa ribs and covered with aluminum skin, to alter the existing airfoil shape to that of the GA(W)-2 airfoil. The aircraft was flown in a flight test program that gathered wing surface pressures and wake data from which the lift drag, and pitching moment of the airfoil could be determined. After the base line performance of the airfoil was measured, the drag due to surface irregularities such as steps, rivets and surface waviness was determined. The potential reduction of drag through the use of surface coatings such as KAPTON was also investigated.

  17. Development of an improved performance SiGe unicouple

    SciTech Connect

    Nakahara, J.F.; Franklin, B.; DeFillipo, L.E.

    1995-01-20

    A two-step diffusion bonding process was developed such that the p-type material is bonded to the SiMo hot shoe first at 1594 K followed by the lower melting point n-type material between 1518 and 1520 K. Standard procedures were used to silicon nitride coat the thermoelectric pellets and to attach the cold side CTE transition and heat rejection components to produce unicouples. Two unicouples successfully withstood simulated rivet operations as would be experienced in the fabrication of a Radioisotope Thermoelectric Generator (RTG) converter to verify the integrity of the tungsten cold shoe to thermoelectric material interface. The performance of these unicouples will be further evaluated in an 18-couple test module. {copyright}American Institute of Physics 1995

  18. Rivited panel surface measurement using photogrammetry

    NASA Technical Reports Server (NTRS)

    Merrick, W. D.; Lobb, V. B.; Lansing, F. L.; Stoller, F. W.

    1986-01-01

    Two riveted antenna panels on rings number 3 and 9 were removed from the 34m antenna at DSS-15, fixed in the leveled position and the surface was photographed indoors. The results from this pilot photogrammetric demonstration and diagnostics of panel surface contours, are presented. The photogrammetric network for each panel incorporated eight photographs, two from each of four camera stations and observed over 200 targets. The accuracy (1 sigma) of the XYZ coordinates for the error ellipsoids was + or - 0.013 mm (0.0005 inch). This level of precision relative to the object size corresponds roughly to 1 part in 250,000 which is superior to conventional dial sweep-arm template techniques by at least a factor of 4.

  19. Evaluation of Pressurization Fatigue Life of 1441 Al-li Fuselage Panel

    NASA Technical Reports Server (NTRS)

    Bird, R. Keith; Dicus, Dennis I.; Fridlyander, Joseph; Davydov, Valentin

    1999-01-01

    A study was conducted to evaluate the pressurization fatigue life of fuselage panels with skins fabricated from 1441 Al-Li, an attractive new Russian alloy. The study indicated that 1441 Al-Li has several advantages over conventional aluminum fuselage skin alloy with respect to fatigue behavior. Smooth 1441 Al-Li sheet specimens exhibited a fatigue endurance limit similar to that for 1163 Al (Russian version of 2024 Al) sheet. Notched 1441 Al-Li sheet specimens exhibited greater fatigue strength and longer fatigue life than 1163 Al. In addition, Tu-204 fuselage panels fabricated by Tupolev Design Bureau using Al-Li skin and ring frames with riveted 7000-series aluminum stiffeners had longer pressurization fatigue lives than did panels constructed from conventional aluminum alloys. Taking into account the lower density of this alloy, the results suggest that 1441 Al-Li has the potential to improve fuselage performance while decreasing structural weight.

  20. Migrants, Manpower and Math in the Coming Europe.

    PubMed

    Evans, Robert G

    2015-11-01

    "A dead child" said stalin "is a tragedy. Two million are a statistic." A single photograph of a beach riveted world attention, converting syrian refugees from statistics to tragedy. But the statistics remain. Three Canadian columnists have offered contrasting interpretations. Eric Reguly argues that a static and aging Europe needs more manpower to sustain its economy. Margaret Wente, however, observes the failure of integration of migrants in Sweden. Migrants are drawn by open borders and a generous welfare state, but do not fit an advanced, high-skill economy. Gwynne Dyer notes that current inflows, IF evenly distributed, are a tiny proportion of the overall European Union. But economic migrants from Africa are a much larger issue. Their numbers are effectively inexhaustible.

  1. Variable-Density Tunnel

    NASA Technical Reports Server (NTRS)

    1921-01-01

    The outside pressure shell for the Variable-Density Tunnel (VDT). The shell, or 'tank' as it was called, was built in the Newport News Shipyard and traveled by barge to Langley. The tank could withstand a working pressure of 21 atmospheres. Elton Miller described it in NACA TR No. 227 (pp. 411-412): 'It is built of steel plates lapped and riveted according to the usual practice in steam boiler construction, although, because of the size of the tank and the high working pressure, the construction is unusually heavy. There is a cylindrical body portion of 2-1/8 inch (53.98 millimeters) steel plate with hemispherical ends 1-1/4 inches (31.75 millimeters) in thickness.'

  2. Development of an adhesively bonded beryllium propulsion structure for the Mariner Mars 1971 spacecraft

    NASA Technical Reports Server (NTRS)

    Stevens, J. H.; Layman, W. E.

    1972-01-01

    The design, testing, and fabrication of the support truss structure for the propulsion system of the Mariner 9 spacecraft are described. Support is provided by an 8.9-kg (19.5-lbm) truss assembly consisting of beryllium tubes adhesively bonded to magnesium end fittings. Beryllium was selected for the tubular struts in the truss because of its exceptionally high stiffness-to-weight ratio. Adhesive bonding, rather than riveting, was utilized to join the struts to the end fittings because of the low toughness (high notch sensitivity) of beryllium. Magnesium, used in the end fittings, resulted in a 50% weight saving over aluminum since geometric factors in the fitting design resulted in low stress areas where magnesium's lower density is a benefit.

  3. Rupture of anterior lens capsule from blunt ocular injury.

    PubMed

    Banitt, Michael R; Malta, João B; Mian, Shahzad I; Soong, H Kaz

    2009-05-01

    We report 3 cases of blunt trauma causing rupture of the anterior lens capsule with cataract formation. The injuries were caused by a paintball gun, a ball-bearing air pistol, and an aluminum rivet. In all 3 cases, the anterior capsule tears were central and the posterior capsules and zonules intact; uneventful cataract extraction with implantation of an intraocular lens was performed. The postoperative visual acuities was 20/40 in 1 case and 20/20 in the other 2 cases. We propose that the anterior lens capsule may have been torn by direct contusion from rapid focal indentation of the cornea onto the lens (coup injury) or by a fluid-mechanical, anteriorly directed rebound of the vitreous, bursting open the anterior capsule (contrecoup injury).

  4. Powered protrusion cutter

    DOEpatents

    Bzorgi, Fariborz M.

    2010-03-09

    An apparatus for clipping a protrusion of material is provided. The protrusion may, for example, be a bolt head, a nut, a rivet, a weld bead, or a temporary assembly alignment tab protruding from a substrate surface of assembled components. The apparatus typically includes a cleaver having a cleaving edge and a cutting blade having a cutting edge. Generally, a mounting structure configured to confine the cleaver and the cutting blade and permit a range of relative movement between the cleaving edge and the cutting edge is provided. Also typically included is a power device coupled to the cutting blade. The power device is configured to move the cutting edge toward the cleaving edge. In some embodiments the power device is activated by a momentary switch. A retraction device is also generally provided, where the retraction device is configured to move the cutting edge away from the cleaving edge.

  5. Device for cutting protrusions

    DOEpatents

    Bzorgi, Fariborz M.

    2011-07-05

    An apparatus for clipping a protrusion of material is provided. The protrusion may, for example, be a bolt head, a nut, a rivet, a weld bead, or a temporary assembly alignment tab protruding from a substrate surface of assembled components. The apparatus typically includes a cleaver having a cleaving edge and a cutting blade having a cutting edge. Generally, a mounting structure configured to confine the cleaver and the cutting blade and permit a range of relative movement between the cleaving edge and the cutting edge is provided. Also typically included is a power device coupled to the cutting blade. The power device is configured to move the cutting edge toward the cleaving edge. In some embodiments the power device is activated by a momentary switch. A retraction device is also generally provided, where the retraction device is configured to move the cutting edge away from the cleaving edge.

  6. Simulation of stress in an innovative combination of composite with metal sheet

    NASA Astrophysics Data System (ADS)

    Wróbel, A.; Płaczek, M.; Buchacz, A.; Słomiany, A.

    2016-08-01

    In this article research of stress impact in multi-point connection glass epoxy composite with a metal sheet with a rivet nuts was presented. Composite materials are increasingly used because of the good mechanical properties and low price. The laminates are composites of a layer structure, characterized by very high strength in the direction of the fibers, their weakness is not good toughness in a direction perpendicular to the layers. Mainly checking of displacements and stresses generated on the sheet as a result of pneumatic actuators load for composite boards was carried out. Glass-epoxy composite consisting of four layers of glass mat with a weight of 1000 g/m2 and an epoxy resin and hardener HG700 LG700 volume ratio of 38/100 was created. Next composite was fixed with steel plate with a rivet nuts and bolts. A model of laminate samples and plate was simulate in Siemens NX 8.5 software. The simulation results will determine stresses and displacements in conjunction newly designed composite sheet. Strength analysis was performed with the use of the module NX Advanced Simulation. FEM is an advanced method for solving systems of differential equations, based on the division of the field into finite elements for which the solution is approximated by specific functions, and performing the actual calculations only for nodes of this division. Due to the complexity of the created object to simplify the elements made to reduce the calculation time. This article presents the study of stresses and displacements in the composite plates joined with sheet metal, in summary of this article, the authors compare the obtainted results with the computer simulation results in the article: " The study of fix composite panel and steel plates on testing stand".

  7. In situ repair welding of steam turbine shroud for replacing a cracked blade

    NASA Astrophysics Data System (ADS)

    Albert, S. K.; Das, C. R.; Ramasubbu, V.; Bhaduri, A. K.; Ray, S. K.; Raj, Baldev

    2002-06-01

    A root-cracked blade in a high-pressure steam turbine of a nuclear power plant had to be replaced with a new blade by cutting the shroud to remove the cracked blade. This necessitated in situ welding of a new shroud piece with the existing shroud after the blade replacement. The in situ welding of the shroud, a 12% Cr martensitic stainless steel with tempered martensite microstructure, was carried out using gastungsten arc welding and 316L austenitic stainless steel filler metal followed by localized postweld heat treatment at 873 K for 1 h using a specially designed electrical resistance-heating furnace. Mock-up trials were carried out to ensure that sound welds could be made under the constraints present during the in situ repair welding operation. In situ metallography of the repair weld after postweld heat treatment confirmed the adequate tempering of the martensitic structure in the heat-affected zone. Metallurgical investigations carried out in the laboratory on a shroud test-piece that had been welded using the same procedure as employed in the field confirmed the success of the in situ repair operation. The alternate option available was replacing the cracked blade and the shroud piece to which it is riveted with a new one, reducing the height of all the blades attached to the shroud by machining, riveting the blades with reduced height to the new shroud, and, finally, dynamic balancing of the entire turbine after completion of the repair. This option is both time-consuming and expensive. Hence, the successful completion of this repair welding resulted in enormous savings both in terms of reducing the downtime of the plant and the cost of the repair. The turbine has been put back into service and has been operating satisfactorily since December 2000.

  8. Mutual Inductance Problem for a System Consisting of a Current Sheet and a Thin Metal Plate

    NASA Technical Reports Server (NTRS)

    Fulton, J. P.; Wincheski, B.; Nath, S.; Namkung, M.

    1993-01-01

    Rapid inspection of aircraft structures for flaws is of vital importance to the commercial and defense aircraft industry. In particular, inspecting thin aluminum structures for flaws is the focus of a large scale R&D effort in the nondestructive evaluation (NDE) community. Traditional eddy current methods used today are effective, but require long inspection times. New electromagnetic techniques which monitor the normal component of the magnetic field above a sample due to a sheet of current as the excitation, seem to be promising. This paper is an attempt to understand and analyze the magnetic field distribution due to a current sheet above an aluminum test sample. A simple theoretical model, coupled with a two dimensional finite element model (FEM) and experimental data will be presented in the next few sections. A current sheet above a conducting sample generates eddy currents in the material, while a sensor above the current sheet or in between the two plates monitors the normal component of the magnetic field. A rivet or a surface flaw near a rivet in an aircraft aluminum skin will disturb the magnetic field, which is imaged by the sensor. Initial results showed a strong dependence of the flaw induced normal magnetic field strength on the thickness and conductivity of the current-sheet that could not be accounted for by skin depth attenuation alone. It was believed that the eddy current imaging method explained the dependence of the thickness and conductivity of the flaw induced normal magnetic field. Further investigation, suggested the complexity associated with the mutual inductance of the system needed to be studied. The next section gives an analytical model to better understand the phenomenon.

  9. Dynamic thermal tomography for nondestructive inspection of aging aircraft

    SciTech Connect

    Del Grande, N.K.; Dolan, K.W.; Durbin, P.F.; Gorvad, M.R.; Shapiro, A.B.

    1993-11-01

    The authors apply dual-band infrared (DBIR) imaging as a dynamic thermal tomography tool for wide area inspection of a Boeing 737 aircraft and several Boeing KC-135 aircraft panels. The analyses are discussed in this report. After flash-heating the aircraft skin, they record synchronized DBIR images every 40 ms, from onset to 8 seconds after the heat flash. They analyze selective DBIR image ratios which enhance surface temperature contrast and remove surface-emissivity clutter. The Boeing 737 and KC-135 aircraft fuselage panels have varying percent thickness losses from corrosion. They established the correlation of percent thickness loss with surface temperature rise (above ambient) for a partially corroded F-18 wing box structure and several aluminum plates which had 6 to 60% thickness losses at milled flat-bottom hole sites. Based on this correlation, lap splice temperatures rise 1C per 24 {plus_minus} 5% material loss at 0.4 s after the heat flash. They tabulate and map corrosion-related percent thickness loss effects for the riveted Boeing 737, and the riveted Boeing KKC-135. They map the fuselage composite thermal inertia, based on the (inverse) slope of the surface temperature versus inverse square root of time. Composite thermal inertia maps characterized shallow skin defects within the lap splice at early times (< 0.3 s) and deeper skin defects within the lap splice at late times (> 0.4 s). Late time composite thermal inertia maps depict where corrosion-related thickness losses occur (e.g., on the inside of the Boeing 737 lap splice, beneath the galley and the latrine). Lap splice sites on a typical Boeing KC-135 panel with low composite thermal inertia values had high skin-thickness losses from corrosion.

  10. Dual-band infrared (DBIR) imaging inspections of Boeing 737 and KC-135 aircraft panels

    SciTech Connect

    Del Grande, N.K.; Dolan, K.W.; Durbin, P.F.; Gorvad, M.R.; Shapiro, A.B.

    1993-08-27

    We apply dual-band infrared (DBIR) imaging as a dynamic thermal tomography tool for wide area inspection of a Boeing 737 aircraft, and several Boeing KC-135 aircraft panels. Our analyses are discussed in this report. After flash-heating the aircraft skin, we record synchronized DBIR images every 40 ms, from onset to 8 seconds after the heat flash. We analyze selective DBIR image ratios which enhance surface temperature contrast and remove surface-emissivity clutter (from dirt, dents, tape, markings, ink, sealants, uneven paint, paint stripper, exposed metal and roughness variations). The Boeing 737 and KC-135 aircraft fuselage panels have varying percent thickness losses from corrosion. We established the correlation of percent thickness loss with surface temperature rise (above ambient) for a partially corroded F-18 wing box structure and several aluminum reference panels. Based on this correlation, lap splice temperatures rise 1{degrees}C per 24 {plus_minus} 5 % material loss at 0.4 s after the heat flash. We show tables, charts and temperature maps of typical lap splice material losses for the riveted (and bonded) Boeing 737, and the riveted (but unbonded) Boeing KC-135. We map the fuselage composite thermal inertia, based on the (inverse) slope of the surface temperature versus inverse square root of time. Composite thermal inertia maps characterize shallow skin defects within the lap splice at early times (<0.3 s) and deeper skin defects within the lap splice at late times (>0.4 s). Late time composite thermal inertia maps depict where corrosion-related thickness losses occur. Lap splice sites on a typical Boeing KC-135 panel with low composite thermal inertia values had high skin-thickness losses from corrosion.

  11. Integral Manufacturing of Composite Skin-Stringer Assembly and Their Stability Analyses

    NASA Astrophysics Data System (ADS)

    Mahfuz, Hassan; Majumdar, Prasun; Saha, Mrinal; Shamery, Frederick; Jeelani, Shaik

    2004-05-01

    Stiffened composite constructions are increasingly being used in the primary structures of aircraft. One key component in these structures is the assembly between the skin and the stringer. The purpose of the stringers sandwiched between two separate layers of skin is to provide structural integrity to a relatively weak skin-structure. Current practice is to fabricate the skin and the stringer separately, assemble them with adhesively bonded joints, and then co-cure the entire assembly in an autoclave. However, the reliability of the joint manufactured in this fashion is not dependable and hence requires riveting of the skin with the stringer by hundreds of mechanical fasteners. Although the mechanical fastener improves the joint reliability, it certainly increases the weight and reduces the strength of the structure by introducing stress concentration points around the rivet holes. In order to eliminate these disadvantages, an innovative low cost manufacturing technique has been developed. The technique utilizes the vacuum assisted resin transfer molding (VARTM) process to co-inject both the skin and the stringer in one integral step. Furthermore, the skin and the stringer are now part of one continuous fabric preform which by default eliminates any adhesive bonding. Several skin-stringer assemblies with plain weave carbon fabric and SC-15 epoxy resin have been manufactured following this procedure. Stability of the manufactured skin-stringer assembly has been investigated experimentally. The extensive analysis focused on the determination of the critical load corresponding to the instability of the structure, failure load and study of the failure mechanisms. Details of manufacturing procedures and experimental investigations are presented in the paper.

  12. Performance analysis of bonded composite doublers on aircraft structures

    SciTech Connect

    Roach, D.

    1995-08-01

    Researchers contend that composite repairs (or structural reinforcement doublers) offer numerous advantages over metallic patches including corrosion resistance, light weight, high strength, elimination of rivets, and time savings in installation. Their use in commercial aviation has been stifled by uncertainties surrounding their application, subsequent inspection and long-term endurance. The process of repairing or reinforcing airplane structures is time consuming and the design is dependent upon an accompanying stress and fatigue analysis. A repair that is too stiff may result in a loss of fatigue life, continued growth of the crack being repaired, and the initiation of a new flaw in the undesirable high stress field around the patch. Uncertainties in load spectrums used to design repairs exacerbates these problems as does the use of rivets to apply conventional doublers. Many of these repair or structural reinforcement difficulties can be addressed through the use of composite doublers. Primary among unknown entities are the effects of non-optimum installations and the certification of adequate inspection procedures. This paper presents on overview of a program intended to introduce composite doubler technology to the US commercial aircraft fleet. In this project, a specific composite application has been chosen on an L-1011 aircraft in order to focus the tasks on application and operation issues. Through the use of laboratory test structures and flight demonstrations on an in-service L-1011 airplane, this study is investigating composite doubler design, fabrication, installation, structural integrity, and non-destructive evaluation. In addition to providing an overview of the L-1011 project, this paper focuses on a series of fatigue and strength tests which have been conducted in order to study the damage tolerance of composite doublers. Test results to-date are presented.

  13. DARLA: Data Assimilation and Remote Sensing for Littoral Applications

    NASA Astrophysics Data System (ADS)

    Jessup, A.; Holman, R. A.; Chickadel, C.; Elgar, S.; Farquharson, G.; Haller, M. C.; Kurapov, A. L.; Özkan-Haller, H. T.; Raubenheimer, B.; Thomson, J. M.

    2012-12-01

    DARLA is 5-year collaborative project that couples state-of-the-art remote sensing and in situ measurements with advanced data assimilation (DA) modeling to (a) evaluate and improve remote sensing retrieval algorithms for environmental parameters, (b) determine the extent to which remote sensing data can be used in place of in situ data in models, and (c) infer bathymetry for littoral environments by combining remotely-sensed parameters and data assimilation models. The project uses microwave, electro-optical, and infrared techniques to characterize the littoral ocean with a focus on wave and current parameters required for DA modeling. In conjunction with the RIVET (River and Inlets) Project, extensive in situ measurements provide ground truth for both the remote sensing retrieval algorithms and the DA modeling. Our goal is to use remote sensing to constrain data assimilation models of wave and circulation dynamics in a tidal inlet and surrounding beaches. We seek to improve environmental parameter estimation via remote sensing fusion, determine the success of using remote sensing data to drive DA models, and produce a dynamically consistent representation of the wave, circulation, and bathymetry fields in complex environments. The objectives are to test the following three hypotheses: 1. Environmental parameter estimation using remote sensing techniques can be significantly improved by fusion of multiple sensor products. 2. Data assimilation models can be adequately constrained (i.e., forced or guided) with environmental parameters derived from remote sensing measurements. 3. Bathymetry on open beaches, river mouths, and at tidal inlets can be inferred from a combination of remotely-sensed parameters and data assimilation models. Our approach is to conduct a series of field experiments combining remote sensing and in situ measurements to investigate signature physics and to gather data for developing and testing DA models. A preliminary experiment conducted at

  14. Ultrasonic Nondestructive Characterization of Adhesive Bonds

    NASA Technical Reports Server (NTRS)

    Qu, Jianmin

    1999-01-01

    Adhesives and adhesive joints are widely used in various industrial applications to reduce weight and costs, and to increase reliability. For example, advances in aerospace technology have been made possible, in part, through the use of lightweight materials and weight-saving structural designs. Joints, in particular, have been and continue to be areas in which weight can be trimmed from an airframe through the use of novel attachment techniques. In order to save weight over traditional riveted designs, to avoid the introduction of stress concentrations associated with rivet holes, and to take full advantage of advanced composite materials, engineers and designers have been specifying an ever-increasing number of adhesively bonded joints for use on airframes. Nondestructive characterization for quality control and remaining life prediction has been a key enabling technology for the effective use of adhesive joints. Conventional linear ultrasonic techniques generally can only detect flaws (delamination, cracks, voids, etc) in the joint assembly. However, more important to structural reliability is the bond strength. Although strength, in principle, cannot be measured nondestructively, a slight change in material nonlinearity may indicate the onset of failure. Furthermore, microstructural variations due to aging or under-curing may also cause changes in the third order elastic constants, which are related to the ultrasonic nonlinear parameter of the polymer adhesive. It is therefore reasonable to anticipate a correlation between changes in the ultrasonic nonlinear acoustic parameter and the remaining bond strength. It has been observed that higher harmonics of the fundamental frequency are generated when an ultrasonic wave passes through a nonlinear material. It seems that such nonlinearity can be effectively used to characterize bond strength. Several theories have been developed to model this nonlinear effect. Based on a microscopic description of the nonlinear

  15. [Theo van Gogh's medical record].

    PubMed

    Voskuil, P H

    1992-09-01

    In the final months of his life Theo van Gogh was admitted to the 'Geneeskundig Gesticht voor Krankzinnigen te Utrecht'. In November 1990 from the archives of the Willem Arntsz Huis, psychiatric centre in Utrecht, the medical files from this period were made available and a transcription was made by Han van Crimpen and Sjraar van Heugten, scientific collaborators of the Van Gogh Museum. From these data it is acceptable to conclude that Theo van Gogh had dementia paralytica and suffered a fast deterioration of his situation in these last few months. It is, however, probable that at least as early as 1886 Theo showed the first symptoms of this disease when he was in Paris, and that he was treated for this reason by dr. Rivet and dr. Gruby. There are insufficient indications that in Vincent van Gogh's case the same diagnosis can be put forward. It is most probable that during Vincent's visit to Theo in Paris in July 1890 in Theo's case symptoms of his medical deterioration were to be seen and this may have influenced the considerations finally leading to Vincent van Gogh's suicide.

  16. Bayesian estimation of crack initiation times from service data

    NASA Technical Reports Server (NTRS)

    Heller, R. A.; Stevens, G. H.

    1977-01-01

    Lockheed C-130 Hercules aircraft have during their service life been periodically inspected and growing cracks around rivet holes were recorded. This record has recently been used to determine the statistical distributions of crack initiation times and the distribution of initial crack sizes. When crack initiation times are calculated from such cracks, by backward extrapolation of the growth relation, the resulting distribution of crack initiation times will indicate a preponderance of short times to crack initiation. If however, such distributions are combined with the reliability of the inspection procedure, the statistical distribution of missed initiation times can be estimated. The method used is based on Bayes theorem which permits the calculation of the 'prior' distribution (initiation times before inspection) from a knowledge of the 'posterior' distribution (initiation times obtained from the inspection) and a 'likelihood function' (reliability of the inspection) procedure. The results indicate that during an early inspection a large percentage of initiation times will be missed and that the fraction of located initiation times increases during later inspections.

  17. Experimental Analysis of Desalination Unit Coupled with Solar Water Lens Concentrator

    NASA Astrophysics Data System (ADS)

    Chaithanya, K. K.; Rajesh, V. R.; Suresh, Rahul

    2016-09-01

    The main problem that the world faces in this scenario is shortage of potable water. Hence this research work rivets to increase the yield of desalination system in an economical way. The integration of solar concentrator and desalination unit can project the desired yield, but the commercially available concentrated solar power technologies (CSP) are not economically viable. So this study proposes a novel method to concentrate ample amount of solar radiation in a cost effective way. Water acting as lens is a highlighted technology initiated in this work, which can be a substitute for CSP systems. And water lens can accelerate the desalination process so as to increase the yield economically. The solar irradiance passing through the water will be concentrated at a focal point, and the concentration depends on curvature of water lens. The experimental analysis of water lens makes use of transparent thin sheet, supported on a metallic structure. The Plano convex shape of water lens is developed by varying the volume of water that is being poured on the transparent thin sheet. From the experimental analysis it is inferred that, as the curvature of water lens increases, solar irradiance can be focused more accurately on to the focus and a higher water temperature is obtained inside the solar still.

  18. Optical Estimation of Depth and Current in a Ebb Tidal Delta Environment

    NASA Astrophysics Data System (ADS)

    Holman, R. A.; Stanley, J.

    2012-12-01

    A key limitation to our ability to make nearshore environmental predictions is the difficulty of obtaining up-to-date bathymetry measurements at a reasonable cost and frequency. Due to the high cost and complex logistics of in-situ methods, research into remote sensing approaches has been steady and has finally yielded fairly robust methods like the cBathy algorithm for optical Argus data that show good performance on simple barred beach profiles and near immunity to noise and signal problems. In May, 2012, data were collected in a more complex ebb tidal delta environment during the RIVET field experiment at New River Inlet, NC. The presence of strong reversing tidal currents led to significant errors in cBathy depths that were phase-locked to the tide. In this paper we will test methods for the robust estimation of both depths and vector currents in a tidal delta domain. In contrast to previous Fourier methods, wavenumber estimation in cBathy can be done on small enough scales to resolve interesting nearshore features.

  19. New method of determination of spot welding-adhesive joint fatigue life using full field strain evolution

    NASA Astrophysics Data System (ADS)

    Sadowski, T.; Kneć, M.

    2016-04-01

    Fatigue tests were conducted since more than two hundred years ago. Despite this long period, as fatigue phenomena are very complex, assessment of fatigue response of standard materials or composites still requires a long time. Quite precise way to estimate fatigue parameters is to test at least 30 standardized specimens for the analysed material and further statistical post processing is required. In case of structural elements analysis like hybrid joints (Figure 1), the situation is much more complex as more factors influence the fatigue load capacity due to much more complicated structure of the joint in comparison to standard materials specimen, i.e. occurrence of: welded hot spots or rivets, adhesive layers, local notches creating the stress concentrations, etc. In order to shorten testing time some rapid methods are known: Locati's method [1] - step by step load increments up to failure, Prot's method [2] - constant increase of the load amplitude up to failure; Lehr's method [2] - seeking for the point during regular fatigue loading when an increase of temperature or strains become non-linear. The present article proposes new method of the fatigue response assessment - combination of the Locati's and Lehr's method.

  20. Time-resolved genetic responses of Lactococcus lactis to a dairy environment.

    PubMed

    Bachmann, Herwig; de Wilt, Leonie; Kleerebezem, Michiel; van Hylckama Vlieg, Johan E T

    2010-05-01

    Lactococcus lactis is one of main bacterial species found in mixed dairy starter cultures for the production of semi-hard cheese. Despite the appreciation that mixed cultures are essential for the eventual properties of the manufactured cheese the vast majority of studies on L. lactis were carried out in laboratory media with a pure culture. In this study we applied an advanced recombinant in vivo expression technology (R-IVET) assay in combination with a high-throughput cheese-manufacturing protocol for the identification and subsequent validation of promoter sequences specifically induced during the manufacturing and ripening of cheese. The system allowed gene expression measurements in an undisturbed product environment without the use of antibiotics and in combination with a mixed strain starter culture. The utilization of bacterial luciferase as reporter enabled the real-time monitoring of gene expression in cheese for up to 200 h after the cheese-manufacturing process was initiated. The results revealed a number of genes that were clearly induced in cheese such as cysD, bcaP, dppA, hisC, gltA, rpsE, purL, amtB as well as a number of hypothetical genes, pseudogenes and notably genetic elements located on the non-coding strand of annotated open reading frames. Furthermore genes that are likely to be involved in interactions with bacteria used in the mixed strain starter culture were identified.

  1. Element Load Data Processor (ELDAP) Users Manual

    NASA Technical Reports Server (NTRS)

    Ramsey, John K., Jr.; Ramsey, John K., Sr.

    2015-01-01

    Often, the shear and tensile forces and moments are extracted from finite element analyses to be used in off-line calculations for evaluating the integrity of structural connections involving bolts, rivets, and welds. Usually the maximum forces and moments are desired for use in the calculations. In situations where there are numerous structural connections of interest for numerous load cases, the effort in finding the true maximum force and/or moment combinations among all fasteners and welds and load cases becomes difficult. The Element Load Data Processor (ELDAP) software described herein makes this effort manageable. This software eliminates the possibility of overlooking the worst-case forces and moments that could result in erroneous positive margins of safety and/or selecting inconsistent combinations of forces and moments resulting in false negative margins of safety. In addition to forces and moments, any scalar quantity output in a PATRAN report file may be evaluated with this software. This software was originally written to fill an urgent need during the structural analysis of the Ares I-X Interstage segment. As such, this software was coded in a straightforward manner with no effort made to optimize or minimize code or to develop a graphical user interface.

  2. Aerothermal performance and structural integrity of a Rene 41 thermal protection system at Mach 6.6

    NASA Technical Reports Server (NTRS)

    Deveikis, W. D.; Miserentino, R.; Weinstein, I.; Shideler, J. L.

    1975-01-01

    A flightweight panel based on a metallic thermal-protection-system concept for hypersonic and reentry vehicles was subjected repeatedly to thermal cycling by quartz-lamp radiant heating using a thermal history representative of a reentry heat pulse and to aerodynamic heating at heating rates required to sustain a surface temperature of 1089 K (1960 R). The panel consisted of a corrugated heat shield and support members of 0.05-cm (0.02-in.) thick Rene 41 of riveted construction and 5.08-cm (2-in.) thick silica fibrous insulation packages covered by Rene 41 foil and inconel screening. All tests were conducted in the Langley 8-foot high-temperature structures tunnel with the heat shield corrugations alined in the stream direction. The panel sustained 5.33 hr of intermittent radiant heating and 6.5 min of intermittent aerodynamic heating of up to 1-min duration for differential pressures up to 6.2 kPa (0.9 psi) with no apparent degradation of thermal or structural integrity, as indicated by temperature distributions and results from load deflection tests and vibration surveys of natural frequencies.

  3. Performance of a hypersonic hot fuselage structure with a carbon dioxide frost projected, nonintegral cryogenic tank

    NASA Technical Reports Server (NTRS)

    Sharpe, E. L.; Jackson, L. R.

    1975-01-01

    A model which consisted of a hot structure and a nonintegral tank protected by a carbon dioxide frost thermal protection system was tested under the following conditions: (1) room temperature loading and (2) heating and loading corresponding to the Mach 8 flight of an air-breathing launch vehicle. In the simulated flight tests, liquid nitrogen inside the tank was withdrawn at the rate fuel would be consumed. Prior to each simulated flight test, carbon dioxide was cryodeposited in the insulation surrounding the tank; during the tests, subliming CO2 frost absorbed heat and provided a purge gas for the space between the tank and the structure. A method of flame spraying the joints between panels with a nickel-aluminum material was developed to prevent excessive leakage of the purge gas through the outer structure. The tests indicated that the hot structure (with a joint repaired by riveting), the nonintegral tank and suspension system, and the carbon dioxide frost thermal protection system provide a workable concept with predictable performance.

  4. Performance optimization of a diagnostic system based upon a simulated strain field for fatigue damage characterization

    NASA Astrophysics Data System (ADS)

    Sbarufatti, C.; Manes, A.; Giglio, M.

    2013-11-01

    The work presented hereafter is about the development of a diagnostic system for crack damage detection, localization and quantification on a typical metallic aeronautical structure (skin stiffened through riveted stringers). Crack detection and characterization are based upon strain field sensitivity to damage. The structural diagnosis is carried out by a dedicated smart algorithm (Artificial Neural Network) which is trained on a database of Finite Element simulations relative to damaged and undamaged conditions, providing the system with an accurate predictor at low overall cost. The algorithm, trained on numerical damage experience, is used in a simulated environment to provide reliable preliminary information concerning the algorithm performances for damage diagnosis, thus further reducing the experimental costs and efforts associated with the development and optimization of such systems. The same algorithm has been tested on real experimental strain patterns acquired during real fatigue crack propagation, thus verifying the capability of the numerically trained algorithm for anomaly detection, damage assessment and localization on a real complex structure. The load variability, the discrepancy between the Finite Element Model and the real structure, and the uncertainty in the algorithm training process have been addressed in order to enhance the robustness of the system inference process. Some further algorithm training strategies are discussed, aimed at minimizing the risk for false alarms while maintaining a high probability of damage detection.

  5. Research into hand-arm vibration syndrome and its prevention in Japan.

    PubMed

    Yamada, S; Sakakibara, H

    1994-05-01

    Research on vibration syndrome in Japan began in the 1930s with studies of the disorder among railway, mining and shipyard workers. In 1947, the Ministry of Labor decided vibration syndrome among operators of rock drills and riveters etc. was an occupational disease. Industrial developments in the 1950s and 1960s promoted the survey of vibration syndrome in mining, stone quarrying and forestry. The Ministry of Labor (1965) and the National Personnel Agency (1966) legally recognized vibration syndrome among chain saw operators as an occupational disease. Guidelines for prevention and early therapy were issued in the 1970s and 80s. From the late 1970s into the 1980s, research focused on the clinical picture, diagnostic methods and therapy. In pathophysiology, advances were made in research into the autonomic nervous system during the 1980s. The 1970s and 80s saw a steady reduction in risk from technological change and working conditions, and advances in medical care, education and meteorological forecasting. A comprehensive prevention system established in the 1980s in the Japanese forest industry involved: 1) work restrictions, 2) an improved health care system, 3) advances in the design of vibrating tools, handle-warming devices, and 4) improved worker education. This comprehensive preventive system was legally introduced into other industries, resulting in a rapid decrease in the incidence of vibration syndrome in Japan. PMID:7708109

  6. Process Development for Stamping Á-Pillar Covers with Aluminum

    SciTech Connect

    Choi, Jung-Pyung; Rohatgi, Aashish; Smith, Mark T.; Lavender, Curt A.

    2015-02-20

    In this work, performed in close collaboration with PACCAR and Magna International, a 6XXX series aluminum alloy was used for the development of A-Pillar cover for the cab of a typical heavy-duty Class-8 truck. The use of Al alloy for the A-pillar cover represents an approximately 40% weight savings over its steel or molded fiberglass composite counterpart. For the selected Al alloy, a small amount of cold work (5% tensile strain), following prior hot-forming, was found to significantly improve the subsequent age-hardening response. The role of solutionizing temperature and rate of cooling on the age-hardening response after paint-bake treatment were investigated. For the temperature range selected in this work, higher solutionizing temperature correlated with greater subsequent age-hardening and vice-versa. However, the age-hardening response was insensitive to the mode of cooling (water quench vs. air cooling). Finally, a two-step forming process was developed where, in the first step, the blank was heated to solutionizing temperature, quenched, and then partially formed at room temperature. For the second step, the pre-form was re-heated and quenched as in the first step, and the forming was completed at room temperature. The resulting A-pillars had sufficient residual ductility to be compatible with hemming and riveting

  7. Development of a biaxial test facility for structural evaluation of aircraft fuselage panels

    SciTech Connect

    Roach, D.; Walkington, P.; Rice, T.

    1998-03-01

    The number of commercial airframes exceeding twenty years of service continues to grow. An unavoidable by-product of aircraft use is that crack and corrosion flaws develop throughout the aircraft`s skin and substructure elements. Economic barriers to the purchase of new aircraft have created an aging aircraft fleet and placed even greater demands on efficient and safe repair methods. Composite doublers, or repair patches, provide an innovative repair technique which can enhance the way aircraft are maintained. Instead of riveting multiple steel or aluminum plates to facilitate an aircraft repair, it is now possible to bond a single Boron-Epoxy composite doubler to the damaged structure. The composite doubler repair process produces both engineering and economic benefits. The FAA`s Airworthiness Assurance Center at Sandia National Labs completed a project to introduce composite doubler repair technology to the commercial aircraft industry. This paper focuses on a specialized structural test facility which was developed to evaluate the performance of composite doublers on actual aircraft structure. The facility can subject an aircraft fuselage section to a combined load environment of pressure (hoop stress) and axial, or longitudinal, stress. The tests simulate maximum cabin pressure loads and use a computerized feedback system to maintain the proper ratio between hoop and axial loads. Through the use of this full-scale test facility it was possible to: (1) assess general composite doubler response in representative flight load scenarios, and (2) verify the design and analysis approaches as applied to an L-1011 door corner repair.

  8. LDEF (Postflight), AO175 : Evaluation of Long-Duration Exposure to the Natural Space Environment on

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO175 : Evaluation of Long-Duration Exposure to the Natural Space Environment on Graphite-Polyimide and Graphite-Epoxy Mechanical Properties, Tray A01 The Graphite-Polyimide and Graphite-Epoxy Mechanical Properties experiment postflight photograph was taken in the Orbiter Processing Facility during the period when the LDEF was being transferred from the Orbiter cargo bay to the KSC Payload Transporter. The photograph shows considerably more detail than the flight photograph. The horizontal lines on the honeycomb panel that appear to be cracks from space exposure are instead fine lines of excess epoxy resin formed during the bagging and curing process. The harsh white color of the epoxy adhesive along the rivet lines is from the lighting conditions in the OPF. The brown discoloration on the paint dots and the stain on the aluminum mounting strips appear to have changed little from the flight photograph. The greater detail does show that a stain exists at most composite and mounting strip interfaces.

  9. The Effects of Impact Vibration on Peripheral Blood Vessels and Nerves

    PubMed Central

    KRAJNAK, Kristine M.; WAUGH, Stacey; JOHNSON, Claud; MILLER, G. Roger; XU, Xueyan; WARREN, Christopher; DONG, Ren G.

    2013-01-01

    Research regarding the risk of developing hand-arm vibration syndrome after exposure to impact vibration has produced conflicting results. This study used an established animal model of vibration-induced dysfunction to determine how exposure to impact vibration affects peripheral blood vessels and nerves. The tails of male rats were exposed to a single bout of impact vibration (15 min exposure, at a dominant frequency of 30 Hz and an unweighted acceleration of approximately 345 m/s2) generated by a riveting hammer. Responsiveness of the ventral tail artery to adrenoreceptor-mediated vasoconstriction and acetylcholine-mediated re-dilation was measured ex vivo. Ventral tail nerves and nerve endings in the skin were assessed using morphological and immunohistochemical techniques. Impact vibration did not alter vascular responsiveness to any factors or affect trunk nerves. However, 4 days following exposure there was an increase in protein-gene product (PGP) 9.5 staining around hair follicles. A single exposure to impact vibration, with the exposure characteristics described above, affects peripheral nerves but not blood vessels. PMID:24077447

  10. Development of an improved performance SiGe unicouple

    NASA Astrophysics Data System (ADS)

    Nakahara, Jan F.; Franklin, Brian; DeFillipo, Lawrence E.

    1995-01-01

    This paper describes the fabrication of unicouples with improved SiGe alloys. Based on laboratory measurements of the thermoelectric properties the improved materials provide about a 10% improvement in the figure-of-merit between 573 and 1273 K compared to standard coarse grain unicouple materials. The improved materials are p-type Si0.796Ge0.199B0.005 fabricated at Martin Marietta Astro Space by the Vacuum casting/hot pressing method and n-type Si0.784Ge0.196Ga0.005P0.015 fabricated at Ames Laboratory by the mechanical alloying/hot isostatic pressing method. The standard unicouple bonding process was adjusted to accommodate the lower melting temperature of the SiGe/GaP material. A two-step diffusion bonding process was developed such that the p-type material is bonded to the SiMo hot shoe first at 1594 K followed by the lower melting point n-type material between 1518 and 1520 K. Standard procedures were used to silicon nitride coat the thermoelectric pellets and to attach the cold side CTE transition and heat rejection components to produce unicouples. Two unicouples successfully withstood simulated rivet operations as would be experienced in the fabrication of a Radioisotope Thermoelectric Generator (RTG) converter to verify the integrity of the tungsten cold shoe to thermoelectric material interface. The performance of these unicouples will be further evaluated in an 18-couple test module.

  11. Preliminary Test Results of a Non-Contacting Finger Seal on a Herringbone-Grooved Rotor

    NASA Technical Reports Server (NTRS)

    Proctor, Margaret P.; Delgado, Irebert R.

    2009-01-01

    The baseline non-contacting finger seal is a NASA patented design. The primary difference between it and Gul Aroras design patented by AlliedSignal is that there are no lift pads on the high pressure fingers. The baseline non-contacting finger seal is comprised of a back plate, aft spacer, aft (or low pressure) finger element, forward (or high pressure) finger element, forward spacer, and front plate. The components are held together with 20 flat head screws. A typical seal would have a back plate of approximately the same thickness as the front plate and would be riveted together. The thicker back plate allows use of threaded fasteners so that different finger elements can be tested without having to replace all the individual seal components. The finger elements are essentially washers made of thin sheet stock with multiple curved slots machined around the inner diameter to form the fingers. They are clocked so that the fingers of one cover the slots of the other. The aft finger element fingers have axial extensions or "lift pads" at the seal id that are concentric to the rotor. The fingers act as cantilever beams and flex in response to rotor dynamic motion and radial growth of the rotor due to centrifugal or thermal forces.

  12. Head-mounted workstation displays for airborne reconnaissance applications

    NASA Astrophysics Data System (ADS)

    Browne, Michael P.

    1998-09-01

    Aircraft reconnaissance operators need to access increasing amounts of information to perform their job effectively. Unfortunately, there is no excess weight, space or power capacity in most airborne platforms for the installation of additional display surfaces. Head mounted workstation displays solve these weight, space and power problems and mitigate information overload by providing a user-friendly interface to displayed information. Savings can be tremendous for large platforms. Over 18 kW of power and over 5,000 pounds could be saved on each Rivet Joint or AWACS platform. Even small platforms such as the E-2C or UAV ground control stations benefit from removal of large, heavy CRT or LCD displays. In addition, head mounted workstation displays provide an increased capability for collaborative mission planning and reduce motion-induced nausea. Kaiser Electronics has already designed and demonstrated a prototype system, VIEWTM, that addresses the needs of the airborne workstation operator. This system is easily reconfigured for multiple tasks and can be designed as a portable workstation for use anywhere within the aircraft (especially for maintenance or supervisory roles). We have validated the VIEWTM design with hundreds of user trials within the airborne reconnaissance community. Adopting such a display system in reconnaissance aircraft will gain significant benefits such as longer on-station time, increased operational altitude and improved operator performance.

  13. Lead abatement system cuts corners, costs for utility company

    SciTech Connect

    Fuller, B.

    1996-11-01

    When Consolidated Edison Co. (New York) called for bids to remove lead from the 125-foot-tall steam-dispersion stacks at its Astoria Power Generating Station, the company specified that no lead could be released into the environment during the project. Another restriction was that any abrasive blasting for surface preparation would have to be accompanied by full-scale containment--including use of airtight seals, ventilation systems, entrance and exit air locks, and impermeable containment material--to ensure minimal discharge to the generating plant below the stack. Prospective contractors also would be required to meet Occupational Safety and Health Administration standards for medical surveillance, hygiene facilities, eating areas and personal protective equipment if lead levels exceeded 30 micrograms per cubic meter. To reduce the cost of erecting and maintaining full containment without jeopardizing health and safety criteria, Con Ed incorporated a practical solution to remove its aging, lead-based paint. The technology, comprised of a Vac-Pac{reg_sign} self-drumming HEPA filtration system, supports up to 10 operators using proprietary scalers and needleguns. The scalers are effective for flat areas, removing coatings at 45 square feet per hour, while the needleguns are designed for use on corners, edges, rivets and bolts.

  14. General-purpose event generators for LHC physics

    SciTech Connect

    Buckley, Andy; Butterworth, Jonathan; Gieseke, Stefan; Grellscheid, David; Hoche, Stefan; Hoeth, Hendrik; Krauss, Frank; Lonnblad, Leif; Nurse, Emily; Richardson, Peter; Schumann, Steffen; Seymour, Michael H.; Sjostrand, Torbjorn; Skands, Peter; Webber, Bryan; /Cambridge U.

    2011-03-03

    We review the physics basis, main features and use of general-purpose Monte Carlo event generators for the simulation of proton-proton collisions at the Large Hadron Collider. Topics included are: the generation of hard-scattering matrix elements for processes of interest, at both leading and next-to-leading QCD perturbative order; their matching to approximate treatments of higher orders based on the showering approximation; the parton and dipole shower formulations; parton distribution functions for event generators; non-perturbative aspects such as soft QCD collisions, the underlying event and diffractive processes; the string and cluster models for hadron formation; the treatment of hadron and tau decays; the inclusion of QED radiation and beyond-Standard-Model processes. We describe the principal features of the Ariadne, Herwig++, Pythia 8 and Sherpa generators, together with the Rivet and Professor validation and tuning tools, and discuss the physics philosophy behind the proper use of these generators and tools. This review is aimed at phenomenologists wishing to understand better how parton-level predictions are translated into hadron-level events as well as experimentalists wanting a deeper insight into the tools available for signal and background simulation at the LHC.

  15. Failure of dissimilar material bonded joints

    NASA Astrophysics Data System (ADS)

    Konstantakopoulou, M.; Deligianni, A.; Kotsikos, G.

    2016-03-01

    Joining of materials in structural design has always been a challenge for engineers. Bolting and riveting has been used for many years, until the emergence of fusion welding which revolutionised construction in areas such as shipbuilding, automotive, infrastructure and consumer goods. Extensive research in the past 50 years has resulted in better understanding of the process and minimised the occurrence of failures associated with fusion welding such as, residual stress cracking, stress corrosion and corrosion fatigue cracking, localised reduction in mechanical properties due to microstructural changes (heat affected zone) etc. Bonding has been a technique that has been proposed as an alternative because it eliminates several of the problems associated with fusion welding. But, despite some applications it has not seen wide use. There is however a renewed interest in adhesively bonded joints, as designers look for ever more efficient structures which inevitably leads to the use and consequently joining of combinations of lightweight materials, often with fundamentally different mechanical and physical properties. This chapter provides a review of adhesively bonded joints and reports on improvements to bonded joint strength through the introduction of carbon nanotubes at the bond interface. Results from various workers in the field are reported as well as the findings of the authors in this area of research. It is obvious that there are several challenges that need to be addressed to further enhance the strength of bonded joints and worldwide research is currently underway to address those shortcomings and build confidence in the implementation of these new techniques.

  16. Loss of butt-end leg bands on male wild turkeys

    USGS Publications Warehouse

    Diefenbach, Duane R.; Casalena, Mary Jo; Schiavone, Michael V.; Swanson, David A.; Reynolds, Michael; Boyd, Robert C.; Eriksen, Robert; Swift, Bryan

    2009-01-01

    We estimated loss of butt-end leg bands on male wild turkeys (Meleagris gallapavo) captured in New York, Ohio, and Pennsylvania (USA) during December–March, 2006–2008. We used aluminum rivet leg bands as permanent marks to estimate loss of regular aluminum, enameled aluminum, anodized aluminum, and stainless steel butt-end leg bands placed below the spur. We used band loss information from 887 turkeys recovered between 31 days and 570 days after release (x¯  =  202 days). Band loss was greater for turkeys banded as adults (>1 yr old) than juveniles and was greater for aluminum than stainless steel bands. We estimated band retention was 79–96%, depending on age at banding and type of band, for turkeys recovered 3 months after release. Band retention was <50% for all age classes and band types 15 months after banding. We concluded that use of butt-end leg bands on male wild turkeys is inappropriate for use in mark–recapture studies.

  17. Eddy Current Inspection of Components with Complex Geometries

    NASA Astrophysics Data System (ADS)

    Plotnikov, Yuri; Wang, Changting; McKnight, William; Suh, Ui

    2008-02-01

    Eddy current (EC) technique is a common inspection method for the detection of open surface cracks and subsurface anomalies. While manual EC inspection is quite reliable on parts with flat (or large curvature) surfaces and parts with consistent subsurface geometry, EC inspection of parts having more complicated surface and subsurface profiles has to rely on automated scan/data collection and post-processing. Examples of the structures with complex geometries are aircraft engine rotating parts and multi-layer aircraft structures (lap joints). Data collection for such structures, in most cases, can be performed by using multiple scans of a single sensor EC probe with multi-frequency excitation. To improve productivity of the inspection, arrays of EC sensors are applied during inspection for surface flaws. In this work, the flexible ECAP (EC array probe) with sensitivity to the cracks of variable orientations is presented. To resolve the complex subsurface geometry of the aircraft skin, pulsed excitation is employed. This makes for a faster data collection and full post-processing capabilities. Conversion to multi-frequency (multi-layer) image analysis is done after data collection is completed. The subsurface flaws present in a particular layer of a riveted lap joint become evident from several EC images, which cannot be accomplished by manual inspection.

  18. Advances in Fatigue and Fracture Mechanics Analyses for Aircraft Structures

    NASA Technical Reports Server (NTRS)

    Newman, J. C., Jr.

    1999-01-01

    This paper reviews some of the advances that have been made in stress analyses of cracked aircraft components, in the understanding of the fatigue and fatigue-crack growth process, and in the prediction of residual strength of complex aircraft structures with widespread fatigue damage. Finite-element analyses of cracked structures are now used to determine accurate stress-intensity factors for cracks at structural details. Observations of small-crack behavior at open and rivet-loaded holes and the development of small-crack theory has lead to the prediction of stress-life behavior for components with stress concentrations under aircraft spectrum loading. Fatigue-crack growth under simulated aircraft spectra can now be predicted with the crack-closure concept. Residual strength of cracked panels with severe out-of-plane deformations (buckling) in the presence of stiffeners and multiple-site damage can be predicted with advanced elastic-plastic finite-element analyses and the critical crack-tip-opening angle (CTOA) fracture criterion. These advances are helping to assure continued safety of aircraft structures.

  19. Advances in Fatigue and Fracture Mechanics Analyses for Metallic Aircraft Structures

    NASA Technical Reports Server (NTRS)

    Newman, J. C., Jr.

    2000-01-01

    This paper reviews some of the advances that have been made in stress analyses of cracked aircraft components, in the understanding of the fatigue and fatigue-crack growth process, and in the prediction of residual strength of complex aircraft structures with widespread fatigue damage. Finite-element analyses of cracked metallic structures are now used to determine accurate stress-intensity factors for cracks at structural details. Observations of small-crack behavior at open and rivet-loaded holes and the development of small-crack theory has lead to the prediction of stress-life behavior for components with stress concentrations under aircraft spectrum loading. Fatigue-crack growth under simulated aircraft spectra can now be predicted with the crack-closure concept. Residual strength of cracked panels with severe out-of-plane deformations (buckling) in the presence of stiffeners and multiple-site damage can be predicted with advanced elastic-plastic finite-element analyses and the critical crack-tip-opening angle (CTOA) fracture criterion. These advances are helping to assure continued safety of aircraft structures.

  20. Occupational lead exposure aboard a tall ship

    SciTech Connect

    Landrigan, P.J.; Straub, W.E.

    1985-01-01

    To evaluate occupational exposures to lead in shipfitters cutting and riveting lead-painted iron plates aboard an iron-hulled sailing vessel, the authors conducted an environmental and medical survey. Lead exposures in seven personal (breathing zone) air samples ranged from 108 to 500 micrograms/mT (mean 257 micrograms/mT); all were above the Occupational Safety and Health Administration (OSHA) standard of 50 micrograms/mT. In two short-term air samples obtained while exhaust ventilation was temporarily disconnected, mean lead exposure rose to 547 micrograms/mT. Blood lead levels in ten shipfitters ranged from 25 to 53 micrograms/dl. Blood lead levels in shipfitters were significantly higher than in other shipyard workers. Smoking shipfitters had significantly higher lead levels than nonsmokers. Lead levels in shipfitters who wore respirators were not lower than in those who wore no protective gear. Four shipfitters had erythrocyte protoporphyrin (EP) concentrations above the adult upper normal limit of 50 micrograms/dl. A close correlation was found between blood lead and EP levels. Prevalence of lead-related symptoms was no higher in shipfitters than in other workers. These data indicate that serious occupational exposure to lead can occur in a relatively small boatyard.

  1. Advances in Structural Integrity Analysis Methods for Aging Metallic Airframe Structures with Local Damage

    NASA Technical Reports Server (NTRS)

    Starnes, James H., Jr.; Newman, James C., Jr.; Harris, Charles E.; Piascik, Robert S.; Young, Richard D.; Rose, Cheryl A.

    2003-01-01

    Analysis methodologies for predicting fatigue-crack growth from rivet holes in panels subjected to cyclic loads and for predicting the residual strength of aluminum fuselage structures with cracks and subjected to combined internal pressure and mechanical loads are described. The fatigue-crack growth analysis methodology is based on small-crack theory and a plasticity induced crack-closure model, and the effect of a corrosive environment on crack-growth rate is included. The residual strength analysis methodology is based on the critical crack-tip-opening-angle fracture criterion that characterizes the fracture behavior of a material of interest, and a geometric and material nonlinear finite element shell analysis code that performs the structural analysis of the fuselage structure of interest. The methodologies have been verified experimentally for structures ranging from laboratory coupons to full-scale structural components. Analytical and experimental results based on these methodologies are described and compared for laboratory coupons and flat panels, small-scale pressurized shells, and full-scale curved stiffened panels. The residual strength analysis methodology is sufficiently general to include the effects of multiple-site damage on structural behavior.

  2. Testing and analysis of a modernized freight wagon's elements flammability

    NASA Astrophysics Data System (ADS)

    Płaczek, M.; Wróbel, A.; Baier, A.

    2016-08-01

    Paper concerns an issue of freight wagon modernization using composite materials. The goal of the project is to elongate the period between repairs (by better corrosion protection) and improve conditions of exploitation of modernized freight wagons (for example easier unloading during winter conditions - no freezes of the charge to the freight wagon body shell). Application of the composite panels to the freight wagon's body shell was proposed as the solution that can solve mentioned problems. The composite panels composed of fiberglass and epoxy resin were proposed. They will be mounted on the body shell using rivet nuts. What is more the body shell of the modernized freight wagon will be painted using an anti-corrosion agent. In this paper the analysis of a flammability of the proposed composition (the composite plate made of fiberglass and epoxy resin mounted to the steel sheet with additional anticorrosion agent) is presented. In the paper results of laboratory tests conducted according to international standards are presented. A series of samples of elements of modernized freight wagons was tested using the created laboratory stand. Obtained results were averaged and the proposed material was assigned to the one of the class of materials for their combustibility.

  3. Development and application of in vivo expression technology (IVET) for analysing microbial gene expression in complex environments.

    PubMed

    Jackson, R W; Giddens, S R

    2006-09-01

    Establishing the mechanisms by which microbes interact with their environment, including eukaryotic hosts, is a major challenge that is essential for the economic utilisation of microbes and their products. Techniques for determining global gene expression profiles of microbes, such as microarray analyses, are often hampered by methodological restraints, particularly the recovery of bacterial transcripts (RNA) from complex mixtures and rapid degradation of RNA. A pioneering technology that avoids this problem is In Vivo Expression Technology (IVET). IVET is a 'promoter-trapping' methodology that can be used to capture nearly all bacterial promoters (genes) upregulated during a microbe-environment interaction. IVET is especially useful because there is virtually no limit to the type of environment used (examples to date include soil, oomycete, a host plant or animal) to select for active microbial promoters. Furthermore, IVET provides a powerful method to identify genes that are often overlooked during genomic annotation, and has proven to be a flexible technology that can provide even more information than identification of gene expression profiles. A derivative of IVET, termed resolvase-IVET (RIVET), can be used to provide spatio-temporal information about environment-specific gene expression. More recently, niche-specific genes captured during an IVET screen have been exploited to identify the regulatory mechanisms controlling their expression. Overall, IVET and its various spin-offs have proven to be a valuable and robust set of tools for analysing microbial gene expression in complex environments and providing new targets for biotechnological development.

  4. Evaluation of fatigue cracks using nonlinearities of acousto-ultrasonic waves acquired by an active sensor network

    NASA Astrophysics Data System (ADS)

    Zhou, Chao; Hong, Ming; Su, Zhongqing; Wang, Qiang; Cheng, Li

    2013-01-01

    There has been increasing interest in using the nonlinear features of acousto-ultrasonic (AU) waves to detect damage onset (e.g., micro-fatigue cracks) due to their high sensitivity to damage with small dimensions. However, most existing approaches are able to infer the existence of fatigue damage qualitatively, but fail to further ascertain its location and severity. A damage characterization approach, in conjunction with the use of an active piezoelectric sensor network, was established, capable of evaluating fatigue cracks in a quantitative manner (including the co-presence of multiple fatigue cracks, and their individual locations and severities). Fundamental investigations, using both experiment and enhanced finite element analysis dedicated to the simulation of nonlinear AU waves, were carried out to link the accumulation of nonlinearities extracted from high-order AU waves to the characteristic parameters of a fatigue crack. A probability-based diagnostic imaging algorithm was developed, facilitating an intuitive presentation of identification results in images. The approach was verified experimentally by evaluating multi-fatigue cracks near rivet holes of a fatigued aluminum plate, showing satisfactory precision in characterizing real, barely visible fatigue cracks. Compared with existing methods, this approach innovatively (i) uses permanently integrated active sensor networks, conducive to automatic and online health monitoring; (ii) characterizes fatigue cracks at a quantitative level; (iii) allows detection of multiple fatigue cracks; and (iv) visualizes identification results in intuitive images.

  5. Analysis of Vibrating Circular Plates Having Non-Uniform Constraints Using the Modal Properties of Free-Edge Plates: Application to Bolted Plates

    NASA Astrophysics Data System (ADS)

    Amabili, M.; Pierandrei, R.; Frosali, G.

    1997-09-01

    The free vibrations of a circular plate having elastic constraints variable according to the angular co-ordinate are investigated. The non-uniform translational and rotational stiffness of the constraints are expanded in the Fourier series; it is assumed that the system presents a symmetry axis. The mode shapes are expanded in a Fourier-Bessel series by using the Rayleigh-Ritz method. The eigenfunctions of the free-edge circular plate vibrating in vacuum are assumed as admissible functions. This choice allows one to compute the potential energy of the plate using the kinetic energy of single modes of free-edge plates. The effect of the in-plane load is included and internal constraints are studied. By using the same technique, the free vibrations of a circular plate resting on an annular, non-uniform, Winkler foundation are investigated. Numerical results are given for the cases studied already, in order to validate the proposed method, and for bolted (or riveted) plates fixed by different numbers of bolts.

  6. Finite Element Model Development and Validation for Aircraft Fuselage Structures

    NASA Technical Reports Server (NTRS)

    Buehrle, Ralph D.; Fleming, Gary A.; Pappa, Richard S.; Grosveld, Ferdinand W.

    2000-01-01

    The ability to extend the valid frequency range for finite element based structural dynamic predictions using detailed models of the structural components and attachment interfaces is examined for several stiffened aircraft fuselage structures. This extended dynamic prediction capability is needed for the integration of mid-frequency noise control technology. Beam, plate and solid element models of the stiffener components are evaluated. Attachment models between the stiffener and panel skin range from a line along the rivets of the physical structure to a constraint over the entire contact surface. The finite element models are validated using experimental modal analysis results. The increased frequency range results in a corresponding increase in the number of modes, modal density and spatial resolution requirements. In this study, conventional modal tests using accelerometers are complemented with Scanning Laser Doppler Velocimetry and Electro-Optic Holography measurements to further resolve the spatial response characteristics. Whenever possible, component and subassembly modal tests are used to validate the finite element models at lower levels of assembly. Normal mode predictions for different finite element representations of components and assemblies are compared with experimental results to assess the most accurate techniques for modeling aircraft fuselage type structures.

  7. Neutron Radiographic Inspection of Industrial Components using Kamini Neutron Source Facility

    NASA Astrophysics Data System (ADS)

    Raghu, N.; Anandaraj, V.; Kasiviswanathan, K. V.; Kalyanasundaram, P.

    2008-03-01

    Kamini (Kalpakkam Mini) reactor is a U233 fuelled, demineralised light water moderated and cooled, beryllium oxide reflected, low power (30 kW) nuclear research reactor. This reactor functions as a neutron source with a flux of 1012 n/cm2 s-1 at core centre with facilitates for carrying out neutron radiography, neutron activation analysis and neutron shielding experiments. There are two beam tubes for neutron radiography. The length/diameter ratio of the collimators is about 160 and the aperture size is 220 mm×70 mm. Flux at the outer end of the beam tube is ˜106-107 n/cm2 s. The north end beam tube is for radiography of inactive object while the south side beam tube is for radiography of radioactive objects. The availability of high neutron flux coupled with good collimated beam provides high quality radiographs with short exposure time. The reactor being a unique national facility for neutron radiography has been utilized in the examination of irradiated components, aero engine turbine blades, riveted plates, automobile chain links and for various types of pyro devices used in the space programme. In this paper, an overview of the salient features of this reactor facility for neutron radiography and our experience in the inspection of a variety of industrial components will be given.

  8. Finite element model for MOI applications using A-V formulation

    NASA Astrophysics Data System (ADS)

    Xuan, L.; Shanker, B.; Udpa, L.; Shih, W.; Fitzpatrick, G.

    2001-04-01

    Magneto-optic imaging (MOI) is a relatively new sensor application of an extension of bubble memory technology to NDT and produce easy-to-interpret, real time analog images. MOI systems use a magneto-optic (MO) sensor to produce analog images of magnetic flux leakage from surface and subsurface defects. The instrument's capability in detecting the relatively weak magnetic fields associated with subsurface defects depends on the sensitivity of the magneto-optic sensor. The availability of a theoretical model that can simulate the MOI system performance is extremely important for optimization of the MOI sensor and hardware system. A nodal finite element model based on magnetic vector potential formulation has been developed for simulating MOI phenomenon. This model has been used for predicting the magnetic fields in simple test geometry with corrosion dome defects. In the case of test samples with multiple discontinuities, a more robust model using the magnetic vector potential Ā and electrical scalar potential V is required. In this paper, a finite element model based on A-V formulation is developed to model complex circumferential crack under aluminum rivets in dimpled countersink.

  9. Effect of thermal exposure, forming, and welding on high-temperature, dispersion-strengthened aluminum alloy: Al-8Fe-1V-2Si

    NASA Technical Reports Server (NTRS)

    Kennedy, J. R.; Gilman, P. S.; Zedalis, M. S.; Skinner, D. J.; Peltier, J. M.

    1991-01-01

    The feasibility of applying conventional hot forming and welding methods to high temperature aluminum alloy, Al-8Fe-1V-2Si (FVS812), for structural applications and the effect of thermal exposure on mechanical properties were determined. FVS812 (AA8009) sheet exhibited good hot forming and resistance welding characteristics. It was brake formed to 90 deg bends (0.5T bend radius) at temperatures greater than or equal to 390 C (730 F), indicating the feasibility of fabricating basic shapes, such as angles and zees. Hot forming of simple contoured-flanged parts was demonstrated. Resistance spot welds with good static and fatigue strength at room and elevated temperatures were readily produced. Extended vacuum degassing during billet fabrication reduced porosity in fusion and resistance welds. However, electron beam welding was not possible because of extreme degassing during welding, and gas-tungsten-arc welds were not acceptable because of severely degraded mechanical properties. The FVS812 alloy exhibited excellent high temperature strength stability after thermal exposures up to 315 C (600 F) for 1000 h. Extended billet degassing appeared to generally improve tensile ductility, fatigue strength, and notch toughness. But the effects of billet degassing and thermal exposure on properties need to be further clarified. The manufacture of zee-stiffened, riveted, and resistance-spot-welded compression panels was demonstrated.

  10. Residual Strength Analysis Methodology: Laboratory Coupons to Structural Components

    NASA Technical Reports Server (NTRS)

    Dawicke, D. S.; Newman, J. C., Jr.; Starnes, J. H., Jr.; Rose, C. A.; Young, R. D.; Seshadri, B. R.

    2000-01-01

    The NASA Aircraft Structural Integrity (NASIP) and Airframe Airworthiness Assurance/Aging Aircraft (AAA/AA) Programs have developed a residual strength prediction methodology for aircraft fuselage structures. This methodology has been experimentally verified for structures ranging from laboratory coupons up to full-scale structural components. The methodology uses the critical crack tip opening angle (CTOA) fracture criterion to characterize the fracture behavior and a material and a geometric nonlinear finite element shell analysis code to perform the structural analyses. The present paper presents the results of a study to evaluate the fracture behavior of 2024-T3 aluminum alloys with thickness of 0.04 inches to 0.09 inches. The critical CTOA and the corresponding plane strain core height necessary to simulate through-the-thickness effects at the crack tip in an otherwise plane stress analysis, were determined from small laboratory specimens. Using these parameters, the CTOA fracture criterion was used to predict the behavior of middle crack tension specimens that were up to 40 inches wide, flat panels with riveted stiffeners and multiple-site damage cracks, 18-inch diameter pressurized cylinders, and full scale curved stiffened panels subjected to internal pressure and mechanical loads.

  11. Use of the dynamic gastro-intestinal model TIM to explore the survival of the yogurt bacterium Streptococcus thermophilus and the metabolic activities induced in the simulated human gut.

    PubMed

    Uriot, Ophélie; Galia, Wessam; Awussi, Ahoefa Ablavi; Perrin, Clarisse; Denis, Sylvain; Chalancon, Sandrine; Lorson, Emilie; Poirson, Chantal; Junjua, Maira; Le Roux, Yves; Alric, Monique; Dary, Annie; Blanquet-Diot, Stéphanie; Roussel, Yvonne

    2016-02-01

    Streptococcus thermophilus, a lactic acid bacterium used to produce yogurts and cheeses is more and more considered for its potential probiotic properties. This implies that additional information should be obtained regarding its survival and metabolic activity in the human Gastro-Intestinal Tract (GIT). In this study, we screened 30 S. thermophilus strains for urease, small heat shock protein, and amino-acid decarboxylase functions which may play a role in survival in the upper part of the GIT. The survival kinetics of 4 strains was investigated using the TIM, a physiologically relevant in vitro dynamic gastric and small intestinal model. The three strains LMD9, PB18O and EBLST20 showed significantly higher survival than CNRZ21 in all digestive compartments of the TIM, which may be related to the presence of urease and heat shock protein functions. When LMD9 bacterial cells were delivered in a fermented milk formula, a significant improvement of survival in the TIM was observed compared to non-fermented milk. With the RIVET (Recombinase In Vivo Expression Technology) method applied to the LMD9 strain, a promoter located upstream of hisS, responsible for the histidyl-transfer RNA synthesis, was found to be specifically activated in the artificial stomach. The data generated on S. thermophilus survival and its adaptation capacities to the digestive tract are essential to establish a list of biomarkers useful for the selection of probiotic strains. PMID:26611166

  12. Use of the dynamic gastro-intestinal model TIM to explore the survival of the yogurt bacterium Streptococcus thermophilus and the metabolic activities induced in the simulated human gut.

    PubMed

    Uriot, Ophélie; Galia, Wessam; Awussi, Ahoefa Ablavi; Perrin, Clarisse; Denis, Sylvain; Chalancon, Sandrine; Lorson, Emilie; Poirson, Chantal; Junjua, Maira; Le Roux, Yves; Alric, Monique; Dary, Annie; Blanquet-Diot, Stéphanie; Roussel, Yvonne

    2016-02-01

    Streptococcus thermophilus, a lactic acid bacterium used to produce yogurts and cheeses is more and more considered for its potential probiotic properties. This implies that additional information should be obtained regarding its survival and metabolic activity in the human Gastro-Intestinal Tract (GIT). In this study, we screened 30 S. thermophilus strains for urease, small heat shock protein, and amino-acid decarboxylase functions which may play a role in survival in the upper part of the GIT. The survival kinetics of 4 strains was investigated using the TIM, a physiologically relevant in vitro dynamic gastric and small intestinal model. The three strains LMD9, PB18O and EBLST20 showed significantly higher survival than CNRZ21 in all digestive compartments of the TIM, which may be related to the presence of urease and heat shock protein functions. When LMD9 bacterial cells were delivered in a fermented milk formula, a significant improvement of survival in the TIM was observed compared to non-fermented milk. With the RIVET (Recombinase In Vivo Expression Technology) method applied to the LMD9 strain, a promoter located upstream of hisS, responsible for the histidyl-transfer RNA synthesis, was found to be specifically activated in the artificial stomach. The data generated on S. thermophilus survival and its adaptation capacities to the digestive tract are essential to establish a list of biomarkers useful for the selection of probiotic strains.

  13. Basic research on design analysis methods for rotorcraft vibrations

    NASA Technical Reports Server (NTRS)

    Hanagud, S.

    1991-01-01

    The objective of the present work was to develop a method for identifying physically plausible finite element system models of airframe structures from test data. The assumed models were based on linear elastic behavior with general (nonproportional) damping. Physical plausibility of the identified system matrices was insured by restricting the identification process to designated physical parameters only and not simply to the elements of the system matrices themselves. For example, in a large finite element model the identified parameters might be restricted to the moduli for each of the different materials used in the structure. In the case of damping, a restricted set of damping values might be assigned to finite elements based on the material type and on the fabrication processes used. In this case, different damping values might be associated with riveted, bolted and bonded elements. The method itself is developed first, and several approaches are outlined for computing the identified parameter values. The method is applied first to a simple structure for which the 'measured' response is actually synthesized from an assumed model. Both stiffness and damping parameter values are accurately identified. The true test, however, is the application to a full-scale airframe structure. In this case, a NASTRAN model and actual measured modal parameters formed the basis for the identification of a restricted set of physically plausible stiffness and damping parameters.

  14. Characterizing spontaneous induction of Stx encoding phages using a selectable reporter system.

    PubMed

    Livny, Jonathan; Friedman, David I

    2004-03-01

    Shiga toxin (Stx) genes in Stx producing Escherichia coli (STEC) are encoded in prophages of the lambda family, such as H-19B. The subpopulation of STEC lysogens with induced prophages has been postulated to contribute significantly to Stx production and release. To study induced STEC, we developed a selectable in vivo expression technology, SIVET, a reporter system adapted from the RIVET system. The SIVET lysogen has a defective H-19B prophage encoding the TnpR resolvase gene downstream of the phage PR promoter and a cat gene with an inserted tet gene flanked by targets for the TnpR resolvase. Expression of resolvase results in excision of tet, restoring a functional cat gene; induced lysogens survive and are chloramphenicol resistant. Using SIVET we show that: (i) approximately 0.005% of the H-19B lysogens are spontaneously induced per generation during growth in LB. (ii) Variations in cellular physiology (e.g. RecA protein) rather than in levels of expressed repressor explain why members of a lysogen population are spontaneously induced. (iii) A greater fraction of lysogens with stx encoding prophages are induced compared to lysogens with non-Stx encoding prophages, suggesting increased sensitivity to inducing signal(s) has been selected in Stx encoding prophages. (iv) Only a small fraction of the lysogens in a culture spontaneously induce and when the lysogen carries two lambdoid prophages with different repressor/operators, 933W and H-19B, usually both prophages in the same cell are induced.

  15. Composition and microstructure of Roman metallic artefacts of Southwestern Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Valério, P.; Voráčová, E.; Silva, R. J. C.; Araújo, M. F.; Soares, A. M. M.; Arruda, A. M.; Pereira, C.

    2015-10-01

    The Roman invasion introduces new alloys and metallurgical practices in Iberian Peninsula. The southwestern end of this region has many evidences of connections with the Roman World, but there are no studies about the manufacture and use of copper-based artefacts during this period. Therefore, a set of about 20 ornaments, tools and small attachments recovered at the Roman sites of Monte Molião and Cidade das Rosas was studied by an analytical approach combining micro-EDXRF, optical microscopy, SEM-EDS and Vickers microhardness testing. The artefact composition shows a good correlation with function, namely pure copper for nails and rivets, low-tin bronze (2-6 wt% Sn) for basic tools, high-tin bronze (14 wt% Sn) for fibulae and high-lead bronze (19 wt% Pb) for a decorated jug handle. The manufacture also depends on function because most artefacts were subjected to thermomechanical processing, except the ornaments that would not benefit from post-casting work. Brass and gunmetal were only present in the site with a later chronology. A metallurgy visibly ruled by economical, aesthetical and technological concerns reinforces the evidences about the total integration of Southwestern Iberian Peninsula in the Roman World, but further studies will be essential to determine the evolution of copper-based alloys in Lusitania under Roman influence.

  16. A 3D Porous Architecture of Si/graphene Nanocomposite as High-performance Anode Materials for Li-ion Batteries

    SciTech Connect

    Xin X.; Zhu Y.; Zhou, X.; Wang, F.; Yao, X.; Xu, X.; Liu, Z.

    2012-04-28

    A 3D porous architecture of Si/graphene nanocomposite has been rationally designed and constructed through a series of controlled chemical processes. In contrast to random mixture of Si nanoparticles and graphene nanosheets, the porous nanoarchitectured composite has superior electrochemical stability because the Si nanoparticles are firmly riveted on the graphene nanosheets through a thin SiO{sub x} layer. The 3D graphene network enhances electrical conductivity, and improves rate performance, demonstrating a superior rate capability over the 2D nanostructure. This 3D porous architecture can deliver a reversible capacity of {approx}900 mA h g{sup -1} with very little fading when the charge rates change from 100 mA g{sup -1} to 1 A g{sup -1}. Furthermore, the 3D nanoarchitechture of Si/graphene can be cycled at extremely high Li{sup +} extraction rates, such as 5 A g{sup -1} and 10 A g{sup -1}, for over than 100 times. Both the highly conductive graphene network and porous architecture are considered to contribute to the remarkable rate capability and cycling stability, thereby pointing to a new synthesis route to improving the electrochemical performances of the Si-based anode materials for advanced Li-ion batteries.

  17. Research into hand-arm vibration syndrome and its prevention in Japan.

    PubMed

    Yamada, S; Sakakibara, H

    1994-05-01

    Research on vibration syndrome in Japan began in the 1930s with studies of the disorder among railway, mining and shipyard workers. In 1947, the Ministry of Labor decided vibration syndrome among operators of rock drills and riveters etc. was an occupational disease. Industrial developments in the 1950s and 1960s promoted the survey of vibration syndrome in mining, stone quarrying and forestry. The Ministry of Labor (1965) and the National Personnel Agency (1966) legally recognized vibration syndrome among chain saw operators as an occupational disease. Guidelines for prevention and early therapy were issued in the 1970s and 80s. From the late 1970s into the 1980s, research focused on the clinical picture, diagnostic methods and therapy. In pathophysiology, advances were made in research into the autonomic nervous system during the 1980s. The 1970s and 80s saw a steady reduction in risk from technological change and working conditions, and advances in medical care, education and meteorological forecasting. A comprehensive prevention system established in the 1980s in the Japanese forest industry involved: 1) work restrictions, 2) an improved health care system, 3) advances in the design of vibrating tools, handle-warming devices, and 4) improved worker education. This comprehensive preventive system was legally introduced into other industries, resulting in a rapid decrease in the incidence of vibration syndrome in Japan.

  18. Structural Health Monitoring of AN Aircraft Joint

    NASA Astrophysics Data System (ADS)

    Mickens, T.; Schulz, M.; Sundaresan, M.; Ghoshal, A.; Naser, A. S.; Reichmeider, R.

    2003-03-01

    A major concern with ageing aircraft is the deterioration of structural components in the form of fatigue cracks at fastener holes, loose rivets and debonding of joints. These faults in conjunction with corrosion can lead to multiple-site damage and pose a hazard to flight. Developing a simple vibration-based method of damage detection for monitoring ageing structures is considered in this paper. The method is intended to detect damage during operation of the vehicle before the damage can propagate and cause catastrophic failure of aircraft components. It is typical that only a limited number of sensors could be used on the structure and damage can occur anywhere on the surface or inside the structure. The research performed was to investigate use of the chirp vibration responses of an aircraft wing tip to detect, locate and approximately quantify damage. The technique uses four piezoelectric patches alternatively as actuators and sensors to send and receive vibration diagnostic signals.Loosening of selected screws simulated damage to the wing tip. The results obtained from the testing led to the concept of a sensor tape to detect damage at joints in an aircraft structure.

  19. Flexible Chip Scale Package and Interconnect for Implantable MEMS Movable Microelectrodes for the Brain

    PubMed Central

    Jackson, Nathan; Muthuswamy, Jit

    2009-01-01

    We report here a novel approach called MEMS microflex interconnect (MMFI) technology for packaging a new generation of Bio-MEMS devices that involve movable microelectrodes implanted in brain tissue. MMFI addresses the need for (i) operating space for movable parts and (ii) flexible interconnects for mechanical isolation. We fabricated a thin polyimide substrate with embedded bond-pads, vias, and conducting traces for the interconnect with a backside dry etch, so that the flexible substrate can act as a thin-film cap for the MEMS package. A double gold stud bump rivet bonding mechanism was used to form electrical connections to the chip and also to provide a spacing of approximately 15–20 µm for the movable parts. The MMFI approach achieved a chip scale package (CSP) that is lightweight, biocompatible, having flexible interconnects, without an underfill. Reliability tests demonstrated minimal increases of 0.35 mΩ, 0.23 mΩ and 0.15 mΩ in mean contact resistances under high humidity, thermal cycling, and thermal shock conditions respectively. High temperature tests resulted in an increase in resistance of > 90 mΩ when aluminum bond pads were used, but an increase of ~ 4.2 mΩ with gold bond pads. The mean-time-to-failure (MTTF) was estimated to be at least one year under physiological conditions. We conclude that MMFI technology is a feasible and reliable approach for packaging and interconnecting Bio-MEMS devices. PMID:20160981

  20. Lightning protection guidelines and test data for adhesively bonded aircraft structures

    NASA Technical Reports Server (NTRS)

    Pryzby, J. E.; Plumer, J. A.

    1984-01-01

    The highly competitive marketplace and increasing cost of energy has motivated manufacturers of general aviation aircraft to utilize composite materials and metal-to-metal bonding in place of conventional fasteners and rivets to reduce weight, obtain smoother outside surfaces and reduce drag. The purpose of this program is protection of these new structures from hazardous lightning effects. The program began with a survey of advance-technology materials and fabrication methods under consideration for future designs. Sub-element specimens were subjected to simulated lightning voltages and currents. Measurements of bond line voltages, electrical sparking, and mechanical strength degradation were made to comprise a data base of electrical properties for new technology materials and basic structural configurations. The second hase of the program involved tests on full scale wing structures which contained integral fuel tanks and which were representative of examples of new technology structures and fuel systems. The purpose of these tests was to provide a comparison between full scale structural measurements and those obtained from the sub-element specimens.

  1. Advances in utilization of structurally integrated sensor networks for health monitoring in commercial applications

    NASA Astrophysics Data System (ADS)

    Lin, Mark; Kumar, Amrita; Qing, Xinlin; Beard, Shawn J.

    2002-07-01

    Structural health monitoring is a new technology that has been increasingly evaluated by the industry as a potential approach to improve the cost and ease of structural inspection. By improving structural inspection, structures can be made safer and more reliable, thus reducing the cost of structure ownership. Acellent Technologies is developing tools for structural health monitoring. The tools Acellent is offering are the SMART Layer and the SMART Suitcase. The SMART Layer is a flexible layer with a distributed array of piezoelectric transducers made using the printed circuit process that allows easy installation onto structures for in-situ sensing. The SMART Suitcase is an instrument that can interact with the SMART Layer and process the information collected from the structures. Acellent has been providing the system to researchers and companies to try out this new technique. Currently, this system is being evaluated by aircraft manufacturers for monitoring fatigue cracks from rivet holes, by an automotive company for inspecting flaws in composite/foam components, and by aerospace companies for detecting damages in composite/honeycomb sandwich structures. Other recent developments include the addition of fiber-optic sensors onto the SMART Layer and proving the SMART Layer for composite RTM process.

  2. Laser vibrometry for guided wave propagation phenomena visualisation and damage detection

    NASA Astrophysics Data System (ADS)

    Malinowski, Pawel; Wandowski, Tomasz; Kudela, Pawel; Ostachowicz, Wieslaw

    2010-05-01

    This paper presents research on the damage localization method. The method is based on guided wave propagation phenomena. The investigation was focused on application of this method to monitor the condition of structural elements such as aluminium or composite panels. These elements are commonly used in aerospace industry and it is crucial to provide a methodology to determine their condition, in order to prevent from unexpected and dangerous collapse of a structure. Propagating waves interact with cracks, notches, rivets, thickness changes, stiffeners and other discontinuities present in structural elements. It means that registering these waves one can obtain information about the structure condition—whether it is damaged or not. Furthermore these methods can be applied not only to aerospace structures but also to wind turbine blades and pipelines. In reported investigation piezoelectric transducer was used to excite guided waves in considered panel. Measurement of the wave field was realized using laser scanning vibrometer that registered the velocity responses at a defined points belonging to a defined mesh. Mesh spacing was investigated in order to ensure fine wave propagation visualisation. Firstly, wave propagation in pristine specimen was investigated. Secondly, artificial damage was introduced to the specimen. Finally, wave interaction with damage was visualised and conclusions regarding potentials of application of laser vibrometer for damage detection were drawn. All the processing was made with the developed MATLAB procedures.

  3. Use of Circular Foldable Nitinol Blades for Resecting Calcified Aortic Heart Valves

    NASA Astrophysics Data System (ADS)

    Hauck, Florian; Wendt, Daniel; Stühle, Sebastian; Kawa, Emilia; Wendt, Hermann; Müller, Wiebke; Thielmann, Matthias; Kipfmüller, Brigitte; Vogel, Bernd; Jakob, Heinz

    2009-08-01

    The use of percutaneous aortic valve implantation is limited, as the native calcified valve is left in situ. A new device has been developed for resecting calcified aortic valves, using collapsible nickel-titanium blades: laser-cut T-structures of Nitinol sheet-material (Ni51Ti49 at.%) have been grinded on a high-speed milling cutter to produce cutting edges which have been given the shape of half-circles afterwards. These have been connected to each other and to struts by using rivets which also serve as articulating axes for the cutting ring. The blades are folded around these axes and retreated into a tube to be inserted in the heart through the calcified valve leaflets. Once released, the cutting edges regain their ring-shape. By combining rotation of the ring with a translating movement against a second ring of slightly greater diameter on the instrument, a punching process is created which cuts the calcified valve leaflets and leaves a circular annulus, where a prosthesis can be fixed. In vitro cutting of artificially calcified valves ( n = 6) resulted in a resection time of t = 22 ± 6.29 s with a maximum turning moment of M = 2.4 ± 1.27 Nm, proving the function and the feasibility of the concept.

  4. Toward a Unified Theory of Silent Seismicity in Central Mexico

    NASA Astrophysics Data System (ADS)

    Cruz-Atienza, V. M.; Rivet, D. N.; Kostoglodov, V.; Husker, A. L.; Legrand, D.; Campillo, M.

    2011-12-01

    During the 2006 slow slip event (SSE) in Guerrero, Mexico, a seismic profile was deployed above the slipping interface. Data from this seismological network generated several observations, including the detection of an ultra-slow velocity layer confined to the uppermost part of the slab (Song et al., Science, 2009), high Poisson's and Vp/Vs ratios within a large slab segment (Kim et al., JGR, 2010), and a transient reduction of surface waves velocity in the middle crust of about 0.2% due to the quasi-static slow-slip process (Rivet et al., GRL, 2011). Based on these observations, we have proceeded as follow. The slip history of the 2006 Guerrero SSE (Radiguet et al., GJI, 2010) was put into a 3D viscoelastic finite difference code, approximating the pore pressure as Pp=B*Pc, where B is the Skempton coefficient (0≤B≤1) and Pc is the confining pressure. Solving the fluid diffusion equation in the model, we find that the silent earthquake induces a widespread decrease of effective pressure, Pe=Pc-Pp (i.e. dilation increase), above the horizontal segment of the plate interface, where the NVT activity has been localized by previous authors (Payero et al., GRL, 2008; Husker et al., submitted, 2011). Assuming a fluid seal along the plate interface as suggested in Cascadia (Audet et al., Nature, 2009), the time-dependent migration (velocity) of confined fluids in the ultra-slow layer is first upward everywhere and then reorganizes by pointing two 'attraction' poles (i.e. low-pressure slab segments), the first one 80-90 km and the second one around 150 km away from the coast. We present NVT relocations obtained with a new and promising technique (Cruz-Atienza et al., in preparation, 2011). This technique is based on NVT energy-like and waveform correlation measurements in the three ground motion components. By superimposing the hypocentral relocations over the evolving Pp lithospheric cross-section, a surprisingly good correlation appears between the slab 'attraction

  5. Development and validation of bonded composite doubler repairs for commercial aircraft.

    SciTech Connect

    Roach, Dennis Patrick; Rackow, Kirk A.

    2007-07-01

    A typical aircraft can experience over 2,000 fatigue cycles (cabin pressurizations) and even greater flight hours in a single year. An unavoidable by-product of aircraft use is that crack, impact, and corrosion flaws develop throughout the aircraft's skin and substructure elements. Economic barriers to the purchase of new aircraft have placed even greater demands on efficient and safe repair methods. The use of bonded composite doublers offers the airframe manufacturers and aircraft maintenance facilities a cost effective method to safely extend the lives of their aircraft. Instead of riveting multiple steel or aluminum plates to facilitate an aircraft repair, it is now possible to bond a single Boron-Epoxy composite doubler to the damaged structure. The FAA's Airworthiness Assurance Center at Sandia National Labs (AANC), Boeing, and Federal Express completed a pilot program to validate and introduce composite doubler repair technology to the U.S. commercial aircraft industry. This project focused on repair of DC-10 fuselage structure and its primary goal was to demonstrate routine use of this repair technology using niche applications that streamline the design-to-installation process. As composite doubler repairs gradually appear in the commercial aircraft arena, successful flight operation data is being accumulated. These commercial aircraft repairs are not only demonstrating the engineering and economic advantages of composite doubler technology but they are also establishing the ability of commercial maintenance depots to safely adopt this repair technique. This report presents the array of engineering activities that were completed in order to make this technology available for widespread commercial aircraft use. Focused laboratory testing was conducted to compliment the field data and to address specific issues regarding damage tolerance and flaw growth in composite doubler repairs. Fatigue and strength tests were performed on a simulated wing repair using a

  6. Surface Modifications in Adhesion and Wetting

    NASA Astrophysics Data System (ADS)

    Longley, Jonathan

    Advances in surface modification are changing the world. Changing surface properties of bulk materials with nanometer scale coatings enables inventions ranging from the familiar non-stick frying pan to advanced composite aircraft. Nanometer or monolayer coatings used to modify a surface affect the macro-scale properties of a system; for example, composite adhesive joints between the fuselage and internal frame of Boeing's 787 Dreamliner play a vital role in the structural stability of the aircraft. This dissertation focuses on a collection of surface modification techniques that are used in the areas of adhesion and wetting. Adhesive joints are rapidly replacing the familiar bolt and rivet assemblies used by the aerospace and automotive industries. This transition is fueled by the incorporation of composite materials into aircraft and high performance road vehicles. Adhesive joints have several advantages over the traditional rivet, including, significant weight reduction and efficient stress transfer between bonded materials. As fuel costs continue to rise, the weight reduction is accelerating this transition. Traditional surface pretreatments designed to improve the adhesion of polymeric materials to metallic surfaces are extremely toxic. Replacement adhesive technologies must be compatible with the environment without sacrificing adhesive performance. Silane-coupling agents have emerged as ideal surface modifications for improving composite joint strength. As these coatings are generally applied as very thin layers (<50 nm), it is challenging to characterize their material properties for correlation to adhesive performance. We circumvent this problem by estimating the elastic modulus of the silane-based coatings using the buckling instability formed between two materials of a large elastic mismatch. The elastic modulus is found to effectively predict the joint strength of an epoxy/aluminum joint that has been reinforced with silane coupling agents. This buckling

  7. Hydrodynamic ram modeling with the immersed boundary method

    SciTech Connect

    Lewis, M.W.; Kashiwa, B.A.; Rauenzahn, R.M.

    1998-03-01

    The authors have modeled a hydrodynamic ram experiment conducted at Wright-Patterson Air Force Base. In the experiment, a projectile traveling at 200 ft/sec impacted and penetrated a simulated airplane wing containing water. The structure consisted of composite panels with stiffeners and rivets, and an aluminum panel. The test included instrumentation to measure strains, accelerations, and pressures. The technique used for modeling this experiment was a multifluid compressible finite volume approach. The solid fields, namely the projectile and the plates which comprised the structure, were represented by a set of discrete, Lagrangian-frame, mass points. These mass points were followed throughout the computation. The contribution of the stress state at each mass point was applied on the grid to determine the stress divergence contribution to the equations of motion and resulting grid based accelerations. This approach has been defined as the immersed boundary method. The immersed boundary method allows the modeling of fluid-structure interaction problems involving material failure. The authors implemented a plate theory to allow the representation of each plate by a surface of mass points. This theory includes bending terms and transverse shear. Arbitrary constitutive models may be used for each plate. Here they describe the immersed boundary method as they have implemented. They then describe the plate theory and its implementation. They discuss the hydrodynamic ram experiment and describe how they modeled it. They compare computed results with test data. They finally conclude with a discussion of benefits and difficulties associated with this modeling approach and possible improvement to it.

  8. Development and validation of nondestructive inspection techniques for composite doubler repairs on commercial aircraft

    SciTech Connect

    Roach, D.; Walkington, P.

    1998-05-01

    Composite doublers, or repair patches, provide an innovative repair technique which can enhance the way aircraft are maintained. Instead of riveting multiple steel or aluminum plates to facilitate an aircraft repair, it is possible to bond a single boron-epoxy composite doubler to the damaged structure. In order for the use of composite doublers to achieve widespread use in the civil aviation industry, it is imperative that methods be developed which can quickly and reliably assess the integrity of the doubler. In this study, a specific composite application was chosen on an L-1011 aircraft in order to focus the tasks on application and operation issues. Primary among inspection requirements for these doublers is the identification of disbonds, between the composite laminate and aluminum parent material, and delaminations in the composite laminate. Surveillance of cracks or corrosion in the parent aluminum material beneath the doubler is also a concern. No single nondestructive inspection (NDI) method can inspect for every flaw type, therefore it is important to be aware of available NDI techniques and to properly address their capabilities and limitations. A series of NDI tests were conducted on laboratory test structures and on full-scale aircraft fuselage sections. Specific challenges, unique to bonded composite doubler applications, were highlighted. An array of conventional and advanced NDI techniques were evaluated. Flaw detection sensitivity studies were conducted on applicable eddy current, ultrasonic, X-ray and thermography based devices. The application of these NDI techniques to composite doublers and the results from test specimens, which were loaded to provide a changing flaw profile, are presented in this report. It was found that a team of these techniques can identify flaws in composite doubler installations well before they reach critical size.

  9. Damage Assessment of Composite Structures Using Digital Image Correlation

    NASA Astrophysics Data System (ADS)

    Caminero, M. A.; Lopez-Pedrosa, M.; Pinna, C.; Soutis, C.

    2014-02-01

    The steady increase of Carbon-Fiber Reinforced Polymer (CFRP) Structures in modern aircraft will reach a new dimension with the entry into service of the Boeing 787 and Airbus 350. Replacement of damaged parts will not be a preferable solution due to the high level of integration and the large size of the components involved. Consequently the need to develop repair techniques and processes for composite components is readily apparent. Bonded patch repair technologies provide an alternative to mechanically fastened repairs with significantly higher performance, especially for relatively thin skins. Carefully designed adhesively bonded patches can lead to cost effective and highly efficient repairs in comparison with conventional riveted patch repairs that cut fibers and introduce highly strained regions. In this work, the assessment of the damage process taking place in notched (open-hole) specimens under uniaxial tensile loading was studied. Two-dimensional (2D) and three-dimensional (3D) Digital Image Correlation (DIC) techniques were employed to obtain full-field surface strain measurements in carbon-fiber/epoxy T700/M21 composite plates with different stacking sequences in the presence of an open circular hole. Penetrant enhanced X-ray radiographs were taken to identify damage location and extent after loading around the hole. DIC strain fields were compared to finite element predictions. In addition, DIC techniques were used to characterise damage and performance of adhesively bonded patch repairs in composite panels under tensile loading. This part of work relates to strength/stiffness restoration of damaged composite aircraft that becomes more important as composites are used more extensively in the construction of modern jet airliners. The behaviour of bonded patches under loading was monitored using DIC full-field strain measurements. Location and extent of damage identified by X-ray radiography correlates well with DIC strain results giving confidence to

  10. Wheat in the Mediterranean revisited – tetraploid wheat landraces assessed with elite bread wheat Single Nucleotide Polymorphism markers

    PubMed Central

    2014-01-01

    Background Single Nucleotide Polymorphism (SNP) panels recently developed for the assessment of genetic diversity in wheat are primarily based on elite varieties, mostly those of bread wheat. The usefulness of such SNP panels for studying wheat evolution and domestication has not yet been fully explored and ascertainment bias issues can potentially affect their applicability when studying landraces and tetraploid ancestors of bread wheat. We here evaluate whether population structure and evolutionary history can be assessed in tetraploid landrace wheats using SNP markers previously developed for the analysis of elite cultivars of hexaploid wheat. Results We genotyped more than 100 tetraploid wheat landraces and wild emmer wheat accessions, some of which had previously been screened with SSR markers, for an existing SNP panel and obtained publically available genotypes for the same SNPs for hexaploid wheat varieties and landraces. Results showed that quantification of genetic diversity can be affected by ascertainment bias but that the effects of ascertainment bias can at least partly be alleviated by merging SNPs to haplotypes. Analyses of population structure and genetic differentiation show strong subdivision between the tetraploid wheat subspecies, except for durum and rivet that are not separable. A more detailed population structure of durum landraces could be obtained than with SSR markers. The results also suggest an emmer, rather than durum, ancestry of bread wheat and with gene flow from wild emmer. Conclusions SNP markers developed for elite cultivars show great potential for inferring population structure and can address evolutionary questions in landrace wheat. Issues of marker genome specificity and mapping need, however, to be addressed. Ascertainment bias does not seem to interfere with the ability of a SNP marker system developed for elite bread wheat accessions to detect population structure in other types of wheat. PMID:24885044

  11. Development program to certify composite doubler repair technique for commercial aircraft

    SciTech Connect

    Roach, D.P.

    1997-07-01

    Commercial airframes exceeding 20 service years often develop crack and corrosion flaws. Bonded composite doublers offer a cost effective method to safely extend aircraft lives. The Federal Aircraft Authority (FAA) has completed a project to introduce composite doubler repair technology to the commercial aircraft industry. Instead of riveting steel or aluminum plates for repair, a single composite doubler may be bonded to the damaged structure. Adhesive bonding eliminates stress concentrations caused by fastener holes. Composites are readily formed into complex shapes for repairing irregular components. Also, composite doublers can be tailored to meet specific anisotropy needs, eliminating structural stiffening in directions other than those required. Other advantages include corrosion resistance, a high strength-to-weight ratio, and potential time savings in installation. One phase of this study developed general methodologies and test programs to ensure proper performance of the technique. A second phase focused on reinforcement of an L-1011 door frame, and encompassed all lifetime tasks such as design, analysis, installation, and nondestructive inspection. This paper overviews the project and details the activities conducted to gain FAA approval for composite doubler use. Structural tests evaluated the damage tolerance and fatigue performance of composite doublers while finite element models were generated to study doubler design issues. Nondestructive inspection procedures were developed and validated using full-scale test articles. Installation dry-runs demonstrated the viability of applying composite doublers in hangar environments. The project`s documentation package was used to support installation of a Boron-Epoxy composite repair on a Delta Air Lines L-1011 aircraft. A second product of the results is a Lockheed Service Bulletin which allows the door corner composite doubler to be installed on all L-1011 aircraft. 9 refs., 10 figs., 2 tabs.

  12. Mapping wave breaking and residual foam using infrared remote sensing

    NASA Astrophysics Data System (ADS)

    Carini, R. J.; Jessup, A. T.; Chickadel, C.

    2012-12-01

    Quantifying wave breaking in the surfzone is important for the advancement of models that seek to accurately predict energy dissipation, near-shore circulation, wave-current interactions, and air-sea gas transfer. Electro-optical remote sensing has been used to try to identify breaking waves. However, the residual foam, left over after the wave has broken, is indistinguishable from active foam in the visible band, which makes identification of active breaking difficult. Here, we explore infrared remote sensing of breaking waves at near-grazing incidence angles to differentiate between active and residual foam in the surfzone. Measurements were made at two field sites: Duck, NC, in September 2010 (Surf Zone Optics) and New River Inlet, NC, in May 2012 (RIVET). At both sites, multiple IR cameras were mounted to a tower onshore, viewing the surfzone at near-grazing incidence angles. For near-grazing incidence angles, small changes in viewing angle, such as those produced by the slope of a wave face, cause large modulations of the infrared signal. Therefore, the passage of waves can be seen in IR imagery. Wave breaking, however, is identified by the resulting foam. Foam has a higher emissivity than undisturbed water and thus appears warmer in an IR image. Residual foam cools quickly [Marmorino and Smith, 2005], thereby making its signal distinct from that of foam produced during active wave breaking. We will use these properties to develop a technique to produce spatial and temporal maps of active breaking and residual foam. These products can then be used to validate current models of surfzone bubbles and foam coverage. From the maps, we can also estimate energy dissipation due to wave breaking in the surfzone and compare this to estimates made with in situ data.; Infrared image of the surfzone at Duck, NC. Examples of actively breaking foam and cool residual foam are labeled.

  13. Bathymetry Estimates on Open Beaches and in Tidal Inlets via Remote Sensing

    NASA Astrophysics Data System (ADS)

    Honegger, D.; Haller, M. C.; Holman, R. A.

    2014-12-01

    Despite its vital importance to coastal hydrodynamics and maritime safety, bathymetry is often unknown or poorly constrained; remote sensing techniques show promise to help fill this gap. It has been shown that spatial gradients of cross-spectral phase can be successfully exploited to estimate highly-resolved, frequency-dependent wavenumber vectors in wave resolving image time series. These frequency-wavenumber vector pairs have proven useful for bathymetry estimation not only through basic inversion of the linear dispersion relation, but also through more complex data assimilation schemes. However, previous efforts are generally limited to open beaches. As part of the DARLA and RIVET I/II experiments (Duck, NC; New River Inlet, NC; Columbia River Mouth, OR/WA), we present application of this methodology to two complementary remote sensors (X-band marine radar and optical video) and to a range of environments, from simple (open beach) to complex (a micro-tidal inlet mouth and an energetic meso-tidal estuary mouth). Bathymetry estimates via linear wave theory (the "cBathy" algorithm), spatially resolved on the order of one wavelength, are shown to reproduce bar gaps along open beaches and the structure of ebb-tidal shoals. These quasi-continuous estimates are provided at significantly greater resolution than those calculated via 3D-FFT methods over similar domain sizes (up to 40+ km2). Mean currents can affect depth inversion estimates through the Doppler shift of the wave field. As the effect scales with the current vector component in the direction of the waves, this term is often negligible on open beaches, but it becomes significant near tidal inlets. Tidal averaging of the Doppler effect induces a depth estimate bias, but it does not appreciably deteriorate depth estimate accuracy in the presence of low-amplitude, oscillatory tidal currents. Additionally, if slack-water events can be identified, the problem can be divided into separate depth- and current-inversions.

  14. Designing a leaner, cleaner machine

    SciTech Connect

    Valenti, M.

    1997-05-01

    With factories cutting back on emissions and municipalities stepping up recycling efforts, environmentalists have cast automobiles as the primary pollution culprit. A concept car called the XCAR, which incorporates a fuel-efficient, low-pollution engine from Australia, may one day rehabilitate automobiles` bad environmental reputation. The XCAR is being designed by XCORP in Malibu, Calif. The company was founded in 1991 to transfer cutting-edge aerospace and defense technologies to business and manufacturing applications. Their goals are to design a next-generation automobile that will use less energy; provide a higher degree of safety by being more impact-resistant; reduce stress on roads, highways, and bridges by its lighter weight, thus extending the life of infrastructure; and be easily recycled and repaired. The company is developing a roadster, a subcompact coupe, and a sports/utility version of the XCAR for American civilian use, as well as a general-purpose version for the US military and a multipurpose car for developing nations. The design of the XCAR includes molded thermoplastic panels, which reduces the vehicle`s overall weight. Thermoplastic also lowers the energy needed to stamp steel parts by eliminating the by-products generated from spot-welding, drilling, and riveting, such as welding fumes and spent machining oils. Using large, molded thermoplastic/aluminum sections for much of the chassis and body assemblies will also reduce the number of parts required by a third compared to conventional autos. In addition, paint application and its attendant solvents are eliminated because the color is molded into the plastic body.

  15. Arthroscopic transtendinous repair of articular-sided pasta (partial articular supraspinatus tendon avulsion) injury

    PubMed Central

    Wang, Yi; Lu, Liangyu; Lu, Zhe; Xiao, Lei; Kang, Yifan; Wang, Zimin

    2015-01-01

    Objective: To evaluate clinical efficacy of arthroscopic transtendinous repair of partial articular-sided PASTA (partial articular supraspinatus tendon avulsion) injury. Methods: From February 2011 to July 2014, 12 cases of PASTA, aged 29 to 72 years with an average of 52.9 ± 13.3 years, were treated arthoscopically. To repair PASTA, articular-sided rotator cuff tear was explored, injury site was punctured and labeled with PDS absorbable monofilament suture (Ethicon, Somerville, NJ, USA) suture, subacromial bursa was cleaned up with acromioplasty, and integrity of bursa-side rotator cuff was assessed. Then with arthroscope in glenohumeral joint, footprint of the bursa-side supraspinatus tendon was preserved, rivets were introduced into the joint through supraspinatus tendon, joint-side partial tear was sutured, and anatomical reconstruction of the rotator cuff footprint was established. The patients were followed up post-operatively for 12-36 months, average 22 ± 7.3 months. The clinical outcomes were emulated with ASES (American Shoulder and Elbow Surgeons) Shoulder Score system and UCLA (University of California at Los Angeles) Shoulder rating scale. Results: The post-operative ASES score was 89.7 ± 5.6, higher than the pre-operative one 49.8 ± 9.8 (t = 12.25, P <0.0001). While UCLA scale increased from the pre-operative 17.3, ± 3.3 to the post-operative 30.4 ± 3.2 points (t = 9.87, P <0.0001), with a satisfaction rate of 11/12 (91.7%). Conclusion: Trans-tendon repair is ideal for PASTA with advantage of maximal preservation of the normal rotator cuff tissue, anatomical reconstruction of the rotator cuff footprint and stable fixation of tendon-bone interface. PMID:25784979

  16. Use of projection moiré for measuring the instantaneous out-of-plane deflections of composite plates subject to bird strike

    NASA Astrophysics Data System (ADS)

    Van Paepegem, W.; Shulev, A.; Moentjens, A.; Harizanova, J.; Degrieck, J.; Sainov, V.

    2008-07-01

    For the new generation aircraft families, the use of fibre-reinforced plastics is considered for the leading edge of the wings. However, this leading edge is very prone to bird strike impact. This paper presents the use of the projection moiré technique to measure the instantaneous out-of-plane deflections of composite plates subject to bird strike. Very strict constraints with regard to (i) high-speed image acquisition, (ii) vibrations of the impact chamber, and (iii) projection and observation angles, complicated substantially the development of the set-up. Moreover, the high frame rates (12,000 fps) required a very intensive illumination. In the optimized configuration, a specially designed grating with gradually changing period is projected by means of special halide hydride lamps through one of the side windows of the impact chamber onto the composite plate riveted in a steel frame. The digital high-speed camera is mounted on the roof of the impact chamber and records through a mirror the object surface with the projected fringe pattern on it. Numerical routines based on local Fourier transform were developed to process the digital images to extract the phase and the out-of-plane displacements. The phase evaluation is possible due to the carrier frequency nature of the projected moiré pattern. This carrier frequency allows separation of the unwanted additive and multiplicative fringe pattern components in the frequency domain via the application of a proper mask. The numerical calculations were calibrated for the bird strike on an aluminum plate, where the plastic deformation could be checked after the test.

  17. Projection Moire measurement of the deflection of composite plates subject to bird strike impact

    NASA Astrophysics Data System (ADS)

    Shulev, A.; Van Paepegem, W.; Harizanova, J.; Moentjens, A.; Degrieck, J.; Sainov, V.

    2007-06-01

    For the new generation aircraft families, the use of fibre-reinforced plastics is considered for the leading edge of the wings. However, this leading edge is very prone to bird strike impact. This paper presents the use of the projection moire technique to measure the out-of-plane deflections of composite plates subject to bird strike. Very strict constraints with regard to: (i) high speed image acquisition, (ii) vibrations of the impact chamber, and (iii) projection and observation angles - complicated substantially the development of the set-up. Moreover, the high frame rates (12000 fps) required a very intensive illumination. In the optimized configuration, a specially designed grating with gradually changing period is projected by means of special Metal Hydride lamps through one of the side windows of the impact chamber onto the composite plate riveted in a steel frame. The digital high speed camera is mounted on the roof of the impact chamber and records through a mirror the object surface with the projected fringe pattern on it. Numerical routines based on Local Fourier Transform were developed to process the digital images, to extract the phase and the out-of-plane displacements. The phase evaluation is possible due to the carrier frequency nature of the projected moire pattern. This carrier frequency allows separation of the unwanted additive and multiplicative fringe pattern components in the frequency domain via the application of a proper mask. The numerical calculations were calibrated for the bird strike of an aluminium plate, where the plastic deformation could be checked after the test.

  18. Indonesian commercial bus drum brake system temperature model

    NASA Astrophysics Data System (ADS)

    Wibowo, D. B.; Haryanto, I.; Laksono, N. P.

    2016-03-01

    Brake system is the most significant aspect of an automobile safety. It must be able to slow the vehicle, quickly intervening and reliable under varying conditions. Commercial bus in Indonesia, which often stops suddenly and has a high initial velocity, will raise the temperature of braking significantly. From the thermal analysis it is observed that for the bus with the vehicle laden mass of 15 tons and initial velocity of 80 km/h the temperature is increasing with time and reaches the highest temperature of 270.1 °C when stops on a flat road and reaches 311.2 °C on a declination road angle, ø, 20°. These temperatures exceeded evaporation temperature of brake oil DOT 3 and DOT 4. Besides that, the magnitude of the braking temperature also potentially lowers the friction coefficient of more than 30%. The brakes are pressed repeatedly and high-g decelerations also causes brake lining wear out quickly and must be replaced every 1 month as well as the emergence of a large thermal stress which can lead to thermal cracking or thermal fatigue crack. Brake fade phenomenon that could be the cause of many buses accident in Indonesia because of the failure of the braking function. The chances of accidents will be even greater when the brake is worn and not immediately replaced which could cause hot spots as rivets attached to the brake drum and brake oil is not changed for more than 2 years that could potentially lower the evaporation temperature because of the effect hygroscopic.

  19. Guided wave nuances for ultrasonic nondestructive evaluation.

    PubMed

    Rose, J L

    2000-01-01

    Recent developments in guided wave generation, reception, and mode control show that increased penetration power and sensitivity are possible. A tone burst function generator and appropriate signal processing are generally used. Variable angle beam and comb-type transducers are the key to this effort. Problems in tubing, piping, hidden corrosion detection in aging aircraft, adhesive and diffusion bonding, and ice detection are discussed. Additionally, sample configurations, inspection objectives, and logic are being developed for such sample problems as defect detection and analysis in lap splice joints, tear straps, cracks in a second layer, hidden corrosion in multiple layers, cracks from rivet holes, transverse cracking in a beam, and cracks in landing gear assembly. Theoretical and experimental aspects of guided wave analysis include phase velocity, group velocity, and attenuation dispersion curves; boundary element model analysis for reflection and transmission factor analysis; use of wave structure for defect detection sensitivity; source influence on the phase velocity spectrum, and the use of angle beam and comb transducer technology. Probe design and modeling considerations are being explored. Utilization of in-plane and out-of-plane displacement patterns on the surface and longitudinal power distribution across the structural cross-section are considered for improved sensitivity, penetration power, and resolution in nondestructive evaluation. Methods of controlling the phase velocity spectrum for mode and frequency selection are available. Such features as group velocity change, mode cut-off measurements, mode conversion, amplitude ratios of transmission, and reflection factors of specific mode and frequency as input will be introduced for their ability to be used in flaw and material characterization analysis.

  20. Assessing the Response of Nematode Communities to Climate Change-Driven Warming: A Microcosm Experiment

    PubMed Central

    Gingold, Ruth; Moens, Tom; Rocha-Olivares, Axayácatl

    2013-01-01

    alternative diversity–ecosystem functioning relationships, such as the Rivets and the Idiosyncrasy Model. PMID:23825552

  1. Guided wave nuances for ultrasonic nondestructive evaluation.

    PubMed

    Rose, J L

    2000-01-01

    Recent developments in guided wave generation, reception, and mode control show that increased penetration power and sensitivity are possible. A tone burst function generator and appropriate signal processing are generally used. Variable angle beam and comb-type transducers are the key to this effort. Problems in tubing, piping, hidden corrosion detection in aging aircraft, adhesive and diffusion bonding, and ice detection are discussed. Additionally, sample configurations, inspection objectives, and logic are being developed for such sample problems as defect detection and analysis in lap splice joints, tear straps, cracks in a second layer, hidden corrosion in multiple layers, cracks from rivet holes, transverse cracking in a beam, and cracks in landing gear assembly. Theoretical and experimental aspects of guided wave analysis include phase velocity, group velocity, and attenuation dispersion curves; boundary element model analysis for reflection and transmission factor analysis; use of wave structure for defect detection sensitivity; source influence on the phase velocity spectrum, and the use of angle beam and comb transducer technology. Probe design and modeling considerations are being explored. Utilization of in-plane and out-of-plane displacement patterns on the surface and longitudinal power distribution across the structural cross-section are considered for improved sensitivity, penetration power, and resolution in nondestructive evaluation. Methods of controlling the phase velocity spectrum for mode and frequency selection are available. Such features as group velocity change, mode cut-off measurements, mode conversion, amplitude ratios of transmission, and reflection factors of specific mode and frequency as input will be introduced for their ability to be used in flaw and material characterization analysis. PMID:18238584

  2. Smart patches: self-monitoring composite patches for the repair of aircraft

    NASA Astrophysics Data System (ADS)

    Crossley, Samuel D.; Marioli-Riga, Zaira; Tsamasphyros, George; Kanderakis, George; Furnarakis, Nikos; Ikiades, Aris; Konstantaki, Mary

    2004-03-01

    Conventional aircraft repair techniques employ bolted or riveted metallic reinforcements, which frequently introduce additional stress concentrations leading to further cracking and creating areas difficult or impossible to inspect. Bonded composite repairs ("patches") result in the elimination of stress concentrations caused by additional fastener holes, improved strength to weight ratio and present a sealed interface. This reduces even further the danger of corrosion and fretting under the repair, gives greater flexibility in design and lessens application time while lengthening fatigue life. Embedding optical fibres and sensors into the patch, and combining this with advanced data collection and processing systems, creating a so-called "smart patch", will enable the real-time assessment of aircraft structural integrity resulting in reliable prediction of maintenance requirements for repaired structures. This paper describes the current state of the art in smart patch technology, and includes a detailed description of the measurement problem and of the work being undertaken to solve it, at both the component and system level. An analysis of typical crack behaviour, based on FE modelling is presented and this demonstrates the need for optical strain sensors having a very short gauge length. The paper discusses the advantages and limitations of very short Fibre Bragg Gratings (FBGs) in this context and also provides early experimental data from 1mm and 2mm gratings which have been fabricated for this purpose. The paper also describes the impact of the measurement and environmental constraints on the design of the FBG interrogation system and presents the results of initial trials. The work is being undertaken in the framework of a collaborative project (ACIDS) which is co-funded by the European Commission.

  3. Upgrading a 1950s tank farm to meet the environmental standards of the 1990S

    SciTech Connect

    Butler, C.F.; Peterson, S.W.

    1995-12-31

    The Texaco Inc. Research and Development (Texaco) facility in Beacon, New York includes an above ground storage tank (AST) farm, known as Tank Farm No. 1, which consists of eighteen tanks with capacities ranging from 10,000 to 21,000 gallons. A second tank farm, at the Texaco, Beacon facility, designated as the Boiler House Tank Farm, includes three additional tanks with capacities from 10,000 to 44,900 gallons. The Tank Farm No. 1 AST systems are all vertical, carbon steel tanks which were initially installed in several phases in the 1950s. The Boiler House Tank Farm ASTs are also vertical, carbon steel tanks, including one riveted construction tank that was installed in 1931. Each of the Texaco ASTs are used to store a variety of petroleum products, including diesel fuel, stoddard solvent, used oil, and various grades of gasoline and gasoline components. The New York State Department of Environmental Conservation (NYSDEC) has established regulations for petroleum bulk storage in 6 NYCRR Parts 612 through 614. These regulations include requirements for monitoring and inspecting AST systems, including a rigorous ``out of service`` inspection, to be completed at least once every ten years. Although several revisions had been completed at Tank Farm No. 1 in recent years, including installation of a reinforced concrete secondary containment dike system and new above ground piping, the tank shells and most appurtenances (e.g. water drawoff valves), were unmodified since they were initially installed. On this basis, Texaco decided to upgrade the AST systems in conjunction with the NYSDEC ten-year inspections, by installing reinforced fiberglass liners in the tank floors, and by removing and/or replacing tank appurtenances to meet current industry standards and fire code requirements. This paper presents a summary of the program implemented to upgrade the Texaco, Beacon tank farm AST systems.

  4. Is long-term ecological functioning stable: The case of the marine benthos?

    NASA Astrophysics Data System (ADS)

    Frid, C. L. J.; Caswell, B. A.

    2015-04-01

    It is widely acknowledged that human activities are contributing to substantial biodiversity loss and that this threatens ecological processes underpinning human exploitation of 'ecosystem services' (defined by the Millennium Ecosystem Assessment as 'the benefits people obtain from ecosystems'). In the present study we consider three 'intermediate ecosystem services' in both contemporary and ancient marine systems and although 'ecosystem services' per se did not exist in the Jurassic our study seeks to consider the future provision of these services and so the term is retained. We consider the temporal patterns in benthic marine ecosystems: (1) spanning four decades at two offshore stations in the North Sea, UK and (2) over millennial scales in Late Jurassic UK palaeocommunities. Biological traits analysis is used to link changes in taxonomic composition to variations in ecological functioning and the potential supply of three 'intermediate' ecosystem services: the ability to provide food to fish and other predators, benthic nutrient regeneration and carbon cycling. We examine whether changes in taxonomic composition drive temporal variation in functioning, whether this variation increases over time and the extent to which species turnover is comparable in contemporary and ancient systems. Taxonomic variability was of a similar magnitude in all three systems and there was evidence for changes in functioning linked to changes in several (key or rivet) taxa. During other periods resilience maintained functioning in the face of taxonomic change. These results suggest that in these benthic systems the Biodiversity-Ecosystem Functioning relationship is idiosyncratic, but a degree of temporal stability in functioning is maintained such that the ecosystem services they underpin would also be stable during decadal and longer-term changes.

  5. Assessing the Response of Nematode Communities to Climate Change-Driven Warming: A Microcosm Experiment.

    PubMed

    Gingold, Ruth; Moens, Tom; Rocha-Olivares, Axayácatl

    2013-01-01

    alternative diversity-ecosystem functioning relationships, such as the Rivets and the Idiosyncrasy Model.

  6. A Comprehensive Review of the Cosmeceutical Benefits of Vanda Species (Orchidaceae).

    PubMed

    Hadi, Hazrina; Razali, Syarifah Nazira Said; Awadh, Ammar Ihsan

    2015-08-01

    Orchidaceae is the largest family of flowering plants with over 35,000 species and 850 genera. About 3300 species of orchids are found in Malaysia and the diversity is highest in the Main, Keledang, Bintang and Tahan Ranges. Apart from being prized for their beauty, orchids have long been used by humans for medicinal purposes. Today the uses of orchids have been expanded to the food and cosmetics industries. Many cosmeceutical companies use orchid extracts as an active ingredient in their products. Previous studies provide riveting insights into the potential uses of orchid extracts as an active agent in cosmetics. This paper describes the cosmeceutical potential of orchids as an anti-aging, and skin moisturizing agent. Orchid extracts from Vanda coerulea and V. teres delay aging caused by reactive oxygen species (ROS) following LV irradiation through their antioxidant and anti-inflammatory activity. These extracts also show anti-aging properties by stimulating cytochrome c oxidase (complex IV), which is part of the electron transport chain in mitochondria. Stimulation of cytochrome c oxidase improves the respiratory function of mitochondria in keratinocytes. The presence of mucilage in orchids enables them to maintain skin hydration. Mucilage functions as a moisturizer and emollient due to its high water binding capacity. Additionally, orchid extracts provide skin hydration by stimulating aquaporin 3 (AQP3) and LEKTI protein expression. The presence of AQP3 leads to a five-fold increase in water permeability, which subsequently increases stratum corneum hydration. Increased LEKTI protein expression mediated by orchid extracts reduces the degradation of desmoglein-1 and enhances the structural function of desmosomes, which play important roles in preventing water evaporation. PMID:26434147

  7. Full-Scale Structural and NDI Validation Tests of Bonded Composite Doublers for Commercial Aircraft Applications

    SciTech Connect

    Roach, D.; Walkington, P.

    1999-02-01

    Composite doublers, or repair patches, provide an innovative repair technique which can enhance the way aircraft are maintained. Instead of riveting multiple steel or aluminum plates to facilitate an aircraft repair, it is possible to bond a single Boron-Epoxy composite doubler to the damaged structure. Most of the concerns surrounding composite doubler technology pertain to long-term survivability, especially in the presence of non-optimum installations, and the validation of appropriate inspection procedures. This report focuses on a series of full-scale structural and nondestructive inspection (NDI) tests that were conducted to investigate the performance of Boron-Epoxy composite doublers. Full-scale tests were conducted on fuselage panels cut from retired aircraft. These full-scale tests studied stress reductions, crack mitigation, and load transfer capabilities of composite doublers using simulated flight conditions of cabin pressure and axial stress. Also, structures which modeled key aspects of aircraft structure repairs were subjected to extreme tension, shear and bending loads to examine the composite laminate's resistance to disbond and delamination flaws. Several of the structures were loaded to failure in order to determine doubler design margins. Nondestructive inspections were conducted throughout the test series in order to validate appropriate techniques on actual aircraft structure. The test results showed that a properly designed and installed composite doubler is able to enhance fatigue life, transfer load away from damaged structure, and avoid the introduction of new stress risers (i.e. eliminate global reduction in the fatigue life of the structure). Comparisons with test data obtained prior to the doubler installation revealed that stresses in the parent material can be reduced 30%--60% through the use of the composite doubler. Tests to failure demonstrated that the bondline is able to transfer plastic strains into the doubler and that the

  8. Optimization of a Lunar Pallet Lander Reinforcement Structure Using a Genetic Algorithm

    NASA Technical Reports Server (NTRS)

    Burt, Adam

    2014-01-01

    In this paper, a unique system level spacecraft design optimization will be presented. A Genetic Algorithm is used to design the global pattern of the reinforcing structure, while a gradient routine is used to adequately stiffen the sub-structure. The system level structural design includes determining the optimal physical location (and number) of reinforcing beams of a lunar pallet lander deck structure. Design of the substructure includes determining placement of secondary stiffeners and the number of rivets required for assembly.. In this optimization, several considerations are taken into account. The primary objective was to raise the primary natural frequencies of the structure such that the Pallet Lander primary structure does not significantly couple with the launch vehicle. A secondary objective is to determine how to properly stiffen the reinforcing beams so that the beam web resists the shear buckling load imparted by the spacecraft components mounted to the pallet lander deck during launch and landing. A third objective is that the calculated stress does not exceed the allowable strength of the material. These design requirements must be met while, minimizing the overall mass of the spacecraft. The final paper will discuss how the optimization was implemented as well as the results. While driven by optimization algorithms, the primary purpose of this effort was to demonstrate the capability of genetic algorithms to enable design automation in the preliminary design cycle. By developing a routine that can automatically generate designs through the use of Finite Element Analysis, considerable design efficiencies, both in time and overall product, can be obtained over more traditional brute force design methods.

  9. Finite Element Analysis of PM1000Ò Beaded Web Hot-Structure

    NASA Astrophysics Data System (ADS)

    Rocha, R.

    as PM1000, present high melting point, along with excellent mechanical properties up to temperatures in its vicinity. Known as hot-structures, these are today seen as one of the most promising concepts for building re-entry vehicles' structures that can also withstand the high temperatures involved, dramatically reducing the production and especially the maintenance costs of such vehicles. Dutch Space and the TUDelft, along with other partners, are developing skin and spar structures whose mass is sufficiently low, and whose thermal stresses are sufficiently reduced as to be able to resist successive re-entry cycles. Due to the high thermal expansion coefficient of such alloys, along with its rather low thermal conductivity, the spar has to be formed into a beaded shape that allows the outer skin to dilate, or else the thermal stresses that would occur would cause the structure to buckle, and ultimately, fail. widely accepted code ABAQUS/Standard. Calculation of the temperature fields on the structure induced by given heat fluxes was followed by attainment of the consequent thermal stresses, using a fully non-linear transient simulation, that included temperature-dependent plastic material behaviour. thermal testing, one brazed, one riveted, and one with a flat spar for comparison objectives. The results obtained from the FEM analysis were compared with the data available from the thermal testing. structures, with little to no plastic deformation of the material, allowing for widespread usage of this concept in the construction of reusable launch vehicles, with the aforementioned advantages in construction and maintenance costs, when compared with present-day structure plus CMC-based (ceramic matrix composites) heat-shield configurations.

  10. Development of a structural health monitoring system for the life assessment of critical transportation infrastructure.

    SciTech Connect

    Roach, Dennis Patrick; Jauregui, David Villegas; Daumueller, Andrew Nicholas

    2012-02-01

    Recent structural failures such as the I-35W Mississippi River Bridge in Minnesota have underscored the urgent need for improved methods and procedures for evaluating our aging transportation infrastructure. This research seeks to develop a basis for a Structural Health Monitoring (SHM) system to provide quantitative information related to the structural integrity of metallic structures to make appropriate management decisions and ensuring public safety. This research employs advanced structural analysis and nondestructive testing (NDT) methods for an accurate fatigue analysis. Metal railroad bridges in New Mexico will be the focus since many of these structures are over 100 years old and classified as fracture-critical. The term fracture-critical indicates that failure of a single component may result in complete collapse of the structure such as the one experienced by the I-35W Bridge. Failure may originate from sources such as loss of section due to corrosion or cracking caused by fatigue loading. Because standard inspection practice is primarily visual, these types of defects can go undetected due to oversight, lack of access to critical areas, or, in riveted members, hidden defects that are beneath fasteners or connection angles. Another issue is that it is difficult to determine the fatigue damage that a structure has experienced and the rate at which damage is accumulating due to uncertain history and load distribution in supporting members. A SHM system has several advantages that can overcome these limitations. SHM allows critical areas of the structure to be monitored more quantitatively under actual loading. The research needed to apply SHM to metallic structures was performed and a case study was carried out to show the potential of SHM-driven fatigue evaluation to assess the condition of critical transportation infrastructure and to guide inspectors to potential problem areas. This project combines the expertise in transportation infrastructure at New

  11. Upper limb dynamic responses to impulsive forces for selected assembly workers.

    PubMed

    Sesto, Mary E; Radwin, Robert G; Block, Walter F; Best, Thomas M

    2006-02-01

    This study evaluated the upper limb, dynamic, mechanical response parameters for 14 male assembly workers recruited from selected jobs based on power tool use. It was hypothesized that the type of power tool operation would affect stiffness, effective mass, and damping of the upper extremity; and workers with symptoms and positive physical examination findings would have different mechanical responses than asymptomatic workers without physical examination findings. Participants included operators who regularly used torque reaction power hand tools, such as nutrunners and screwdrivers, and nontorque reaction power hand tools, such as riveters. The mechanical parameters of the upper limb were characterized from the loading response of an apparatus having known dynamic properties while worker grasps an oscillating handle in free vibration. In addition, all workers underwent a physical examination, magnetic resonance imaging, and completed a symptom survey. Workers were categorized as controls or cases based on reported forearm symptoms and physical exam findings. A total of seven workers were categorized as cases and had less average mechanical stiffness (46%, p > 0.01), damping (74%, p > 0.01), and effective mass (59%, p > 0.05) than the seven workers categorized as controls. Magnetic resonance imaging (MRI) findings suggestive of muscle edema were observed for two workers classified as cases and who regularly used torque reaction power tools. No MRI enhancement was observed in the seven subjects who did not regularly use torque reaction power tools. The ergonomic consequences of less stiffness, effective mass, and damping in symptomatic workers may include reduced capacity to react against rapidly building torque reaction forces encountered when operating power hand tools. PMID:16361220

  12. On the development of a strength prediction methodology for fibre metal laminates in pin bearing

    NASA Astrophysics Data System (ADS)

    Krimbalis, Peter Panagiotis

    The development of Fibre Metal Laminates (FMLs) for application into aerospace structures represents a paradigm shift in airframe and material technology. By consolidating both monolithic metallic alloys and fibre reinforced composite layers, a new material structure is born exhibiting desired qualities emerging from its heterogeneous constituency. When mechanically fastened via pins, bolts and rivets, these laminated materials develop damage and ultimately fail via mechanisms that were not entirely understood and different than either their metallic or composite constituents. The development of a predictive methodology capable of characterizing how FMLs fastened with pins behave and fail would drastically reduce the amount of experimentation necessary for material qualification and be an invaluable design tool. The body of this thesis discusses the extension of the characteristic dimension approach to FMLs and the subsequent development of a new failure mechanism as part of a progressive damage finite element (FE) modeling methodology with yielding, delamination and buckling representing the central tenets of the new mechanism. This yielding through delamination buckling (YDB) mechanism and progressive FE model were investigated through multiple experimental studies. The experimental investigations required the development of a protocol with emphasis on measuring deformation on a local scheme in addition to a global one. With the extended protocol employed, complete characterization of the material response was possible and a new definition for yield in a pin bearing configuration was developed and subsequently extended to a tensile testing configuration. The performance of this yield definition was compared directly to existing definitions and was shown to be effective in both quasi-isotropic and orthotropic materials. The results of the experiments and FE simulations demonstrated that yielding (according to the new definition), buckling and delamination

  13. a Multi-Data Source and Multi-Sensor Approach for the 3d Reconstruction and Visualization of a Complex Archaelogical Site: the Case Study of Tolmo de Minateda

    NASA Astrophysics Data System (ADS)

    Torres-Martínez, J. A.; Seddaiu, M.; Rodríguez-Gonzálvez, P.; Hernández-López, D.; González-Aguilera, D.

    2015-02-01

    The complexity of archaeological sites hinders to get an integral modelling using the actual Geomatic techniques (i.e. aerial, closerange photogrammetry and terrestrial laser scanner) individually, so a multi-sensor approach is proposed as the best solution to provide a 3D reconstruction and visualization of these complex sites. Sensor registration represents a riveting milestone when automation is required and when aerial and terrestrial dataset must be integrated. To this end, several problems must be solved: coordinate system definition, geo-referencing, co-registration of point clouds, geometric and radiometric homogeneity, etc. Last but not least, safeguarding of tangible archaeological heritage and its associated intangible expressions entails a multi-source data approach in which heterogeneous material (historical documents, drawings, archaeological techniques, habit of living, etc.) should be collected and combined with the resulting hybrid 3D of "Tolmo de Minateda" located models. The proposed multi-data source and multi-sensor approach is applied to the study case of "Tolmo de Minateda" archaeological site. A total extension of 9 ha is reconstructed, with an adapted level of detail, by an ultralight aerial platform (paratrike), an unmanned aerial vehicle, a terrestrial laser scanner and terrestrial photogrammetry. In addition, the own defensive nature of the site (i.e. with the presence of three different defensive walls) together with the considerable stratification of the archaeological site (i.e. with different archaeological surfaces and constructive typologies) require that tangible and intangible archaeological heritage expressions can be integrated with the hybrid 3D models obtained, to analyse, understand and exploit the archaeological site by different experts and heritage stakeholders.

  14. Locating fatigue damage using temporal signal features of nonlinear Lamb waves

    NASA Astrophysics Data System (ADS)

    Hong, Ming; Su, Zhongqing; Lu, Ye; Sohn, Hoon; Qing, Xinlin

    2015-08-01

    The temporal signal features of linear guided waves, as typified by the time-of-flight (ToF), have been exploited intensively for identifying damage, with proven effectiveness in locating gross damage in particular. Upon re-visiting the conventional, ToF-based detection philosophy, the present study extends the use of temporal signal processing to the realm of nonlinear Lamb waves, so as to reap the high sensitivity of nonlinear Lamb waves to small-scale damage (e.g., fatigue cracks), and the efficacy of temporal signal processing in locating damage. Nonlinear wave features (i.e., higher-order harmonics) are extracted using networked, miniaturized piezoelectric wafers, and reverted to the time domain for damage localization. The proposed approach circumvents the deficiencies of using Lamb wave features for evaluating undersized damage, which are either undiscernible in time-series analysis or lacking in temporal information in spectral analysis. A probabilistic imaging algorithm is introduced to supplement the approach, facilitating the presentation of identification results in an intuitive manner. Through numerical simulation and then experimental validation, two damage indices (DIs) are comparatively constructed, based, respectively, on linear and nonlinear temporal features of Lamb waves, and used to locate fatigue damage near a rivet hole of an aluminum plate. Results corroborate the feasibility and effectiveness of using temporal signal features of nonlinear Lamb waves to locate small-scale fatigue damage, with enhanced accuracy compared with linear ToF-based detection. Taking a step further, a synthesized detection strategy is formulated by amalgamating the two DIs, targeting continuous and adaptive monitoring of damage from its onset to macroscopic formation.

  15. Crack growth monitoring at CFRP bond lines

    NASA Astrophysics Data System (ADS)

    Rahammer, M.; Adebahr, W.; Sachse, R.; Gröninger, S.; Kreutzbruck, M.

    2016-02-01

    With the growing need for lightweight technologies in aerospace and automotive industries, fibre-reinforced plastics, especially carbon-fibre (CFRP), are used with a continuously increasing annual growth rate. A promising joining technique for composites is adhesive bonding. While rivet holes destroy the fibres and cause stress concentration, adhesive bond lines distribute the load evenly. Today bonding is only used in secondary structures due to a lack of knowledge with regard to long-term predictability. In all industries, numerical simulation plays a critical part in the development process of new materials and structures, while it plays a vital role when it comes to CFRP adhesive bondings conducing the predictability of life time and damage tolerance. The critical issue with adhesive bondings is crack growth. In a dynamic tensile stress testing machine we dynamically load bonded CFRP coupon specimen and measure the growth rate of an artificially started crack in order to feed the models with the results. We also investigate the effect of mechanical crack stopping features. For observation of the bond line, we apply two non-contact NDT techniques: Air-coupled ultrasound in slanted transmission mode and active lockin-thermography evaluated at load frequencies. Both methods give promising results for detecting the current crack front location. While the ultrasonic technique provides a slightly higher accuracy, thermography has the advantage of true online monitoring, because the measurements are made while the cyclic load is being applied. The NDT methods are compared to visual inspection of the crack front at the specimen flanks and show high congruence. Furthermore, the effect of crack stopping features within the specimen on the crack growth is investigated. The results show, that not all crack fronts are perfectly horizontal, but all of them eventually come to a halt in the crack stopping feature vicinity.

  16. Automated generation of weld path trajectories.

    SciTech Connect

    Sizemore, John M.; Hinman-Sweeney, Elaine Marie; Ames, Arlo Leroy

    2003-06-01

    AUTOmated GENeration of Control Programs for Robotic Welding of Ship Structure (AUTOGEN) is software that automates the planning and compiling of control programs for robotic welding of ship structure. The software works by evaluating computer representations of the ship design and the manufacturing plan. Based on this evaluation, AUTOGEN internally identifies and appropriately characterizes each weld. Then it constructs the robot motions necessary to accomplish the welds and determines for each the correct assignment of process control values. AUTOGEN generates these robot control programs completely without manual intervention or edits except to correct wrong or missing input data. Most ship structure assemblies are unique or at best manufactured only a few times. Accordingly, the high cost inherent in all previous methods of preparing complex control programs has made robot welding of ship structures economically unattractive to the U.S. shipbuilding industry. AUTOGEN eliminates the cost of creating robot control programs. With programming costs eliminated, capitalization of robots to weld ship structures becomes economically viable. Robot welding of ship structures will result in reduced ship costs, uniform product quality, and enhanced worker safety. Sandia National Laboratories and Northrop Grumman Ship Systems worked with the National Shipbuilding Research Program to develop a means of automated path and process generation for robotic welding. This effort resulted in the AUTOGEN program, which has successfully demonstrated automated path generation and robot control. Although the current implementation of AUTOGEN is optimized for welding applications, the path and process planning capability has applicability to a number of industrial applications, including painting, riveting, and adhesive delivery.

  17. Load monitoring of aerospace structures utilizing micro-electro-mechanical systems for static and quasi-static loading conditions

    NASA Astrophysics Data System (ADS)

    Martinez, M.; Rocha, B.; Li, M.; Shi, G.; Beltempo, A.; Rutledge, R.; Yanishevsky, M.

    2012-11-01

    The National Research Council Canada (NRC) has worked on the development of structural health monitoring (SHM) test platforms for assessing the performance of sensor systems for load monitoring applications. The first SHM platform consists of a 5.5 m cantilever aluminum beam that provides an optimal scenario for evaluating the ability of a load monitoring system to measure bending, torsion and shear loads. The second SHM platform contains an added level of structural complexity, by consisting of aluminum skins with bonded/riveted stringers, typical of an aircraft lower wing structure. These two load monitoring platforms are well characterized and documented, providing loading conditions similar to those encountered during service. In this study, a micro-electro-mechanical system (MEMS) for acquiring data from triads of gyroscopes, accelerometers and magnetometers is described. The system was used to compute changes in angles at discrete stations along the platforms. The angles obtained from the MEMS were used to compute a second, third or fourth order degree polynomial surface from which displacements at every point could be computed. The use of a new Kalman filter was evaluated for angle estimation, from which displacements in the structure were computed. The outputs of the newly developed algorithms were then compared to the displacements obtained from the linear variable displacement transducers connected to the platforms. The displacement curves were subsequently post-processed either analytically, or with the help of a finite element model of the structure, to estimate strains and loads. The estimated strains were compared with baseline strain gauge instrumentation installed on the platforms. This new approach for load monitoring was able to provide accurate estimates of applied strains and shear loads.

  18. Adhesive bonding of resin composite to various titanium surfaces using different metal conditioners and a surface modification system

    PubMed Central

    ALMILHATTI, Hercules Jorge; NEPPELENBROEK, Karin Hermana; VERGANI, Carlos Eduardo; MACHADO, Ana Lúcia; PAVARINA, Ana Cláudia; GIAMPAOLO, Eunice Teresinha

    2013-01-01

    Objective This study evaluated the effect of three metal conditioners on the shear bond strength (SBS) of a prosthetic composite material to cpTi grade I having three surface treatments. Material and Methods One hundred sixty eight rivet-shaped specimens (8.0x2.0 mm) were cast and subjected to polishing (P) or sandblasting with either 50 mm (50SB) or 250 mm (250SB) Al2O3. The metal conditioners Metal Photo Primer (MPP), Cesead II Opaque Primer (OP), Targis Link (TL), and one surface modification system Siloc (S), were applied to the specimen surfaces, which were covered with four 1-mm thick layers of resin composite. The resin layers were exposed to curing light for 90 s separately. Seven specimens from each experimental group were stored in water at 37ºC for 24 h while the other 7 specimens were subjected to 5,000 thermal cycles consisting of water baths at 4ºC and 60ºC (n=7). All specimens were subjected to SBS test (0.5 mm/min) until failure occurred, and further 28 specimens were analyzed using scanning electron microscope (SEM) and X-ray energy-dispersive spectroscopy (EDS). Data were analyzed by 3-way ANOVA followed by post-hoc Tukey's test (α=0.05). Results On 50SB surfaces, OP groups showed higher SBS means than MPP (P<0.05), while no significant difference was found among OP, S, and TL groups. On 250SB surfaces, OP and TL groups exhibited higher SBS than MPP and S (P<0.05). No significant difference in SBS was found between OP and TL groups nor between MPP and S groups. The use of conditioners on 250SB surfaces resulted in higher SBS means than the use of the same products on 50SB surfaces (P<0.05). Conclusion Sandblasting associated with the use of metal conditioners improves SBS of resin composites to cpTi. PMID:24473727

  19. Materials Design for Joinable, High Performance Aluminum Alloys

    NASA Astrophysics Data System (ADS)

    Glamm, Ryan James

    An aluminum alloy compatible with friction stir welding is designed for automotive and aerospace structural applications. Current weldable automotive aluminum alloys do not possess the necessary strength to meet safety standards and therefore are not able to replace steel in the automotive body. Significant weight savings could be achieved if steel components are replaced with aluminum. Current aerospace alloys are not weldable, requiring machining of large pieces that are then riveted together. If an aerospace alloy could be friction stir welded, smaller pieces could be welded, reducing material waste. Using a systems approach for materials design, property goals are set from performance objectives. From previous research and computational predictions, a structure is designed for a prototype alloy containing dynamic precipitates to readily dissolve and re-precipitate and high stability precipitates to resist dissolution and coarsening in the weld region. It is found that a Ag modified Al-3.9Mg-0.04Cu (at. %) alloy enhanced the rate and magnitude of hardening during ageing, both beneficial effects for dynamic precipitation. In the same alloy, ageing at 350°C results in hardening from Al 3(Sc,Zr) precipitates. Efforts to effectively precipitate both populations simultaneously are unsuccessful. The Al3(Sc,Zr) precipitation hardened prototype is friction stir processed and no weak zones are found in the weld hardness profile. An aerospace alloy design is proposed, utilizing the dual precipitate structure shown in the prototype. The automotive alloy is designed using a basic strength model with parameters determined from the initial prototype alloy analysis. After ageing to different conditions, the alloy is put through a simulated heat affected zone thermal cycle with a computer controlled induction heater. The aged samples lose hardness from the weld cycle but recover hardness from a post weld heat treatment. Atom probe tomography and transmission electron

  20. Mechanically fastened composite laminates subjected to combined bearing-bypass and shear loading

    NASA Technical Reports Server (NTRS)

    Madenci, Erdogan

    1993-01-01

    Bolts and rivets provide a means of load transfer in the construction of aircraft. However, they give rise to stress concentrations and are often the source and location of static and fatigue failures. Furthermore, fastener holes are prone to cracks during take-off and landing. These cracks present the most common origin of structural failures in aircraft. Therefore, accurate determination of the contact stresses associated with such loaded holes in mechanically fastened joints is essential to reliable strength evaluation and failure prediction. As the laminate is subjected to loading, the contact region, whose extent is not known, develops between the fastener and the hole boundary through this contact region, which consists of slip and no-slip zones due to friction. The presence of the unknown contact stress distribution over the contact region between the pin and the composite laminate, material anisotropy, friction between the pin and the laminate, pin-hole clearance, combined bearing-bypass and shear loading, and finite geometry of the laminate result in a complex non-linear problem. In the case of bearing-bypass loading in compression, this non-linear problem is further complicated by the presence of dual contact regions. Previous research concerning the analysis of mechanical joints subjected to combined bearing-bypass and shear loading is non-existent. In the case of bearing-bypass loading only, except for the study conducted by Naik and Crews (1991), others employed the concept of superposition which is not valid for this non-linear problem. Naik and Crews applied a linear finite element analysis with conditions along the pin-hole contact region specified as displacement constraint equations. The major shortcoming of this method is that the variation of the contract region as a function of the applied load should be known a priori. Also, their analysis is limited to symmetric geometry and material systems, and frictionless boundary conditions. Since the

  1. Characterization of functionalized self-assembled monolayers and surface-attached interlocking molecules using near-edge X-ray absorption fine structure spectroscopy

    NASA Astrophysics Data System (ADS)

    Willey, Trevor Michael

    Quantitative knowledge of the fundamental structure and substrate binding, as well as the direct measurement of conformational changes, are essential to the development of self-assembled monolayers (SAMs) and surface-attached interlocking molecules, catenanes and rotaxanes. These monolayers are vital to development of nano-mechanical, molecular electronic, and biological/chemical sensor applications. This dissertation investigates properties of functionalized SAMs in sulfur-gold based adsorbed molecular monolayers using quantitative spectroscopic techniques including near-edge x-ray absorption fine structure spectroscopy (NEXAFS) and x-ray photoelectron spectroscopy (XPS). The stability of the gold-thiolate interface is addressed. A simple model SAM consisting of dodecanethiol adsorbed on Au(111) degrades significantly in less than 24 hours under ambient laboratory air. S 2p and O 1s XPS show the gold-bound thiolates oxidize to sulfinates and sulfonates. A reduction of organic material on the surface and a decrease in order are observed as the layer degrades. The effect of the carboxyl vs. carboxylate functionalization on SAM structure is investigated. Carboxyl-terminated layers consisting of long alkyl-chain thiols vs. thioctic acid with short, sterically separated, alkyl groups are compared and contrasted. NEXAFS shows a conformational change, or chemical switchability, with carboxyl groups tilted over and carboxylate endgroups more upright. Surface-attached loops and simple surface-attached rotaxanes are quantitatively characterized, and preparation conditions that lead to desired films are outlined. A dithiol is often insufficient to form a molecular species bound at each end to the substrate, while a structurally related disulfide-containing polymer yields surface-attached loops. Similarly, spectroscopic techniques show the successful production of a simple, surface-attached rotaxane that requires a "molecular riveting" step to hold the mechanically attached

  2. Validity of self reported occupational exposures to hand transmitted and whole body vibration

    PubMed Central

    Palmer, K.; Haward, B.; Griffin, M.; Bendall, H.; Coggon, D.

    2000-01-01

    OBJECTIVES—To assess the accuracy with which workers report their exposure to occupational sources of hand transmitted (HTV) and whole body vibration (WBV).
METHODS—179 Workers from various jobs involving exposure to HTV or WBV completed a self administered questionnaire about sources of occupational exposure to vibration in the past week. They were then observed at work over 1 hour, after which they completed a second questionnaire concerning their exposures during this observation period. The feasibility of reported sources of exposure during the past week was examined by questioning managers and by inspection of tools and machines in the workplace. The accuracy of reported sources and durations of exposure in the 1 hour period were assessed relative to what had been observed.
RESULTS—The feasibility of exposure in the previous week was confirmed for 97% of subjects who reported exposure to HTV, and for 93% of subjects who reported exposure to WBV. The individual sources of exposure reported were generally plausible, but occupational use of cars was substantially overreported, possibly because of confusion with their use in travel to and from work. The accuracy of exposures reported during the observation period was generally high, but some sources of HTV were confused—for example, nailing and stapling guns reported as riveting hammers, and hammer drills not distinguished from other sorts of drill. Workers overestimated their duration of exposure to HTV by a median factor of 2.5 (interquartile range (IQR) 1.6-5.9), but estimated durations of exposure were more accurate when the exposure was relatively continuous rather than for intermittent short periods. Reported durations of exposure to WBV were generally accurate (median ratio of reported to observed time 1.1, IQR 1.0-1.2).
CONCLUSIONS—Sources of recent occupational exposure to vibration seem to be reported with reasonable accuracy, but durations of exposure to HTV are systematically

  3. Fatigue test of a fiberglass based composite panel. Increasing the lifetime of freight wagon

    NASA Astrophysics Data System (ADS)

    Sobek, M.; Baier, A.; Grabowski, Ł.; Majzner, M.

    2016-08-01

    In the XXI century transportation of goods plays a key role in the economy. Due to a good logistics the economy is able to grow fluently. Although land transportation is carried out mainly through trucks for the last several years there has been noted an increase in the percentage share of rail transport in the freight transport. The main goods transported by railways are mineral fuels, mining and quarrying products. They constitute the greater part of 70% of total transported goods. Transportation of material of such high weight, high hardness and with different shapes involves increased and accelerated wear and tear of the cargo space of the wagon. This process is also magnified by substances used to prevent overheating or goods theft. Usually they are in the form of chemical compounds powder, eg. Calcium. A very large impact on the wear of the freight wagons hull is made because of mechanical damage. Their source comes mostly from loading cargo with impetus and using heavy machines during unloading. A large number of cycles of loading and unloading during the working period causes abrasion of body and as a result after several years a wagon car qualifies for a major maintenance. Possibility of application composite panels in the process of renovating the wagons body could reduce the weight of whole train and prolong the service life between mandatory technical inspection. The Paper "Fatigue test of a fiberglass based composite panel. Increasing the lifetime of freight wagon" presents the research process and the results of the endurance test of the composite panel samples fixed to a metal plate. As a fixing method a stainless steel rivet nut and a stainless steel button head socket screws were chosen. Cyclic and multiple load were applied to test samples using a pneumatic cylinder. Such a methodology simulated the forces resulting from loading and unloading of the wagon and movement of the cargo during transport. In the study a dedicated stand equipped with a

  4. Characterization of Functionalized Self-Assembled Monolayers and Surface-Attached Interlocking Molecules Using Near-Edge X-ray Absorption Fine Structure Spectroscopy

    SciTech Connect

    Willey, Trevor M.

    2004-04-01

    Quantitative knowledge of the fundamental structure and substrate binding, as well as the direct measurement of conformational changes, are essential to the development of self-assembled monolayers (SAMs) and surface-attached interlocking molecules, catenanes and rotaxanes. These monolayers are vital to development of nano-mechanical, molecular electronic, and biological/chemical sensor applications. This dissertation investigates properties of functionalized SAMs in sulfur-gold based adsorbed molecular monolayers using quantitative spectroscopic techniques including near-edge x-ray absorption fine structure spectroscopy (NEXAFS) and x-ray photoelectron spectroscopy (XPS). The stability of the gold-thiolate interface is addressed. A simple model SAM consisting of dodecanethiol adsorbed on Au(111) degrades significantly in less than 24 hours under ambient laboratory air. S 2p and O 1s XPS show the gold-bound thiolates oxidize to sulfinates and sulfonates. A reduction of organic material on the surface and a decrease in order are observed as the layer degrades. The effect of the carboxyl vs. carboxylate functionalization on SAM structure is investigated. Carboxyl-terminated layers consisting of long alkyl-chain thiols vs. thioctic acid with short, sterically separated, alkyl groups are compared and contrasted. NEXAFS shows a conformational change, or chemical switchability, with carboxyl groups tilted over and carboxylate endgroups more upright. Surface-attached loops and simple surface-attached rotaxanes are quantitatively characterized, and preparation conditions that lead to desired films are outlined. A dithiol is often insufficient to form a molecular species bound at each end to the substrate, while a structurally related disulfide-containing polymer yields surface-attached loops. Similarly, spectroscopic techniques show the successful production of a simple, surface-attached rotaxane that requires a ''molecular riveting'' step to hold the mechanically attached

  5. Further Evolution of Composite Doubler Aircraft Repairs Through a Focus on Niche Applications

    SciTech Connect

    ROACH,DENNIS P.

    2000-07-15

    The number of commercial airframes exceeding twenty years of service continues to grow. A typical aircraft can experience over 2,000 fatigue cycles (cabin pressurizations) and even greater flight hours in a single year. An unavoidable by-product of aircraft use is that crack and corrosion flaws develop throughout the aircraft's skin and substructure elements. Economic barriers to the purchase of new aircraft have created an aging aircraft fleet and placed even greater demands on efficient and safe repair methods. The use of bonded composite doublers offers the airframe manufacturers and aircraft maintenance facilities a cost effective method to safety extend the lives of their aircraft. Instead of riveting multiple steel or aluminum plates to facilitate an aircraft repair, it is now possible to bond a single Boron-Epoxy composite doubler to the damaged structure. The FAA's Airworthiness Assurance Center at Sandia National Labs (AANC) is conducting a program with Boeing and Federal Express to validate and introduce composite doubler repair technology to the US commercial aircraft industry. This project focuses on repair of DC-10 structure and builds on the foundation of the successful L-1011 door corner repair that was completed by the AANC, Lockheed-Martin, and Delta Air Lines. The L-1011 composite doubler repair was installed in 1997 and has not developed any flaws in over three years of service, As a follow-on effort, this DC-1O repair program investigated design, analysis, performance (durability, flaw containment, reliability), installation, and nondestructive inspection issues. Current activities are demonstrating regular use of composite doubler repairs on commercial aircraft. The primary goal of this program is to move the technology into niche applications and to streamline the design-to-installation process. Using the data accumulated to date, the team has designed, analyzed, and developed inspection techniques for an array of composite doubler repairs

  6. Simulation tools for robotics research and assessment

    NASA Astrophysics Data System (ADS)

    Fields, MaryAnne; Brewer, Ralph; Edge, Harris L.; Pusey, Jason L.; Weller, Ed; Patel, Dilip G.; DiBerardino, Charles A.

    2016-05-01

    The Robotics Collaborative Technology Alliance (RCTA) program focuses on four overlapping technology areas: Perception, Intelligence, Human-Robot Interaction (HRI), and Dexterous Manipulation and Unique Mobility (DMUM). In addition, the RCTA program has a requirement to assess progress of this research in standalone as well as integrated form. Since the research is evolving and the robotic platforms with unique mobility and dexterous manipulation are in the early development stage and very expensive, an alternate approach is needed for efficient assessment. Simulation of robotic systems, platforms, sensors, and algorithms, is an attractive alternative to expensive field-based testing. Simulation can provide insight during development and debugging unavailable by many other means. This paper explores the maturity of robotic simulation systems for applications to real-world problems in robotic systems research. Open source (such as Gazebo and Moby), commercial (Simulink, Actin, LMS), government (ANVEL/VANE), and the RCTA-developed RIVET simulation environments are examined with respect to their application in the robotic research domains of Perception, Intelligence, HRI, and DMUM. Tradeoffs for applications to representative problems from each domain are presented, along with known deficiencies and disadvantages. In particular, no single robotic simulation environment adequately covers the needs of the robotic researcher in all of the domains. Simulation for DMUM poses unique constraints on the development of physics-based computational models of the robot, the environment and objects within the environment, and the interactions between them. Most current robot simulations focus on quasi-static systems, but dynamic robotic motion places an increased emphasis on the accuracy of the computational models. In order to understand the interaction of dynamic multi-body systems, such as limbed robots, with the environment, it may be necessary to build component

  7. XB-70A landing with drag chutes deployed

    NASA Technical Reports Server (NTRS)

    1960-01-01

    raised for high-speed flight to reduce drag and lowered for greater visibility during takeoff and landing. The forward fuselage was constructed of riveted titanium frames and skin. The remainder of the airplane was constructed almost entirely of stainless steel. The skin was a brazed stainless-steel honeycomb material. Six General Electric YJ93-3 turbojet engines, each in the 30,000-pound-thrust class, powered the XB-70. Internal geometry of the inlets was controllable to maintain the most efficient airflow to the engines.

  8. Structural development of laminar flow control aircraft chordwise wing joint designs

    NASA Technical Reports Server (NTRS)

    Fischler, J. E.; Jerstad, N. M.; Gallimore, F. H., Jr.; Pollard, T. J.

    1989-01-01

    For laminar flow to be achieved, any protuberances on the surface must be small enough to avoid transition to turbulent flow. However, the surface must have joints between the structural components to allow assembly or replacement of damaged parts, although large continuous surfaces can be utilized to minimize the number the number of joints. Aircraft structural joints usually have many countersunk bolts or rivets on the outer surface. To maintain no mismatch on outer surfaces, it is desirable to attach the components from the inner surface. It is also desirable for the panels to be interchangeable, without the need for shims at the joint, to avoid surface discontinuities that could cause turbulence. Fabricating components while pressing their outer surfaces against an accurate mold helps to ensure surface smoothness and continuity at joints. These items were considered in evaluating the advantages and disadvantages of the joint design concepts. After evaluating six design concepts, two of the leading candidates were fabricated and tested using many small test panels. One joint concept was also built and tested using large panels. The small and large test panel deflections for the leading candidate designs at load factors up to +1.5 g's were well within the step and waviness requirements for avoiding transition.The small panels were designed and tested for compression and tension at -65 F, at ambient conditions, and at 160 F. The small panel results for the three-rib and the sliding-joint concepts indicated that they were both acceptable. The three-rib concept, with tapered splice plates, was considered to be the most practical. A modified three-rib joint that combined the best attributes of previous candidates was designed, developed, and tested. This improved joint met all of the structural strength, surface smoothness, and waviness criteria for laminar flow control (LFC). The design eliminated all disadvantages of the initial three-rib concept except for

  9. Conception axiomatique des joints hybrides a recouvrement simple en materiaux composites

    NASA Astrophysics Data System (ADS)

    Ouellet, Marc

    Minimizing weight is a primary objective in every system design in the aerospace and automotive industry. Therefore, the use of composite materials has become an integral part of the design of mechanical components. However, in composite structure design, their complexity normally makes it impossible to design them as a single part. This leads to the necessity of using joints. Sadly, these joints introduce discontinuities in the stress distribution within the components and are often the sites of stress concentration. Therefore, they may limit the performance of a structure, in addition to increasing the overall mass significantly due to the use of mechanical fasteners such as bolts and rivets. This is why bonded joints are increasingly popular. They are much lighter than bolted or riveted joints and are often more rigid. Unfortunately, it is very difficult to inspect a bonded joint for defects since the presence of cracks in the adhesive cannot be observed with the naked eye. The main objective of this work is to propose a new design methodology for hybrid joints. To accomplish this, it is necessary to establish reliable analysis tools to improve our understanding of the behavior of these joints when subjected to an external force. A better understanding of the interactions between the parameters is also required. To improve our knowledge on the subject, a literature review was conducted. This review was structured as to emphasize on the behavior of hybrid single lap joints when subjected to an external force in tension. Following this literature review, an analysis of the stress distribution within the joint was carried out using a finite element model. The model and the results were compared with those from two papers in order to validate the quality of representation. Subsequently, a modification was made to an existing analytical model in order to add the bolts' preload as a parameter. These two models, namely the finite element model and the analytical model

  10. PREFACE: Radiation Damage in Biomolecular Systems (RADAM07)

    NASA Astrophysics Data System (ADS)

    McGuigan, Kevin G.

    2008-03-01

    The annual meeting of the COST P9 Action `Radiation damage in biomolecular systems' took place from 19-22 June 2007 in the Royal College of Surgeons in Ireland, in Dublin. The conference was structured into 5 Working Group sessions: Electrons and biomolecular interactions Ions and biomolecular interactions Radiation in physiological environments Theoretical developments for radiation damage Track structure in cells Each of the five working groups presented two sessions of invited talks. Professor Ron Chesser of Texas Tech University, USA gave a riveting plenary talk on `Mechanisms of Adaptive Radiation Responses in Mammals at Chernobyl' and the implications his work has on the Linear-No Threshold model of radiation damage. In addition, this was the first RADAM meeting to take place after the Alexander Litvenenko affair and we were fortunate to have one of the leading scientists involved in the European response Professor Herwig Paretzke of GSF-Institut für Strahlenschutz, Neuherberg, Germany, available to speak. The remaining contributions were presented in the poster session. A total of 72 scientific contributions (32 oral, 40 poster), presented by 97 participants from 22 different countries, gave an overview on the current progress in the 5 different subfields. A 1-day pre-conference `Early Researcher Tutorial Workshop' on the same topic kicked off on 19 June attended by more than 40 postgrads, postdocs and senior researchers. Twenty papers, based on these reports, are included in this volume of Journal of Physics: Conference Series. All the contributions in this volume were fully refereed, and they represent a sample of the courses, invited talks and contributed talks presented during RADAM07. The interdisciplinary RADAM07 conference brought together researchers from a variety of different fields with a common interest in biomolecular radiation damage. This is reflected by the disparate backgrounds of the authors of the papers presented in these proceedings

  11. Flexible Cryogenic Temperature and Liquid-Level Probes

    NASA Technical Reports Server (NTRS)

    Haberbusch, Mark

    2005-01-01

    and of associated external electronic circuitry. In each probe, the diodes and the lead wires are embedded in a strong, lightweight, flexible polyimide strip. Each probe is constructed as an integral unit that includes a multipin input/output plug or socket for solderless connection of the lead wires to the external circuitry. The polyimide strip includes mounting tabs with holes that can accommodate rivets, screws, or other fasteners. Alternatively, a probe can be mounted by use of an epoxy. A probe can be manufactured to almost any length or width, and the diodes can be embedded at almost any desired location along and across the polyimide strip. In designing a probe for a specific application, one seeks a compromise between (1) minimizing the number of diodes in order to minimize the complexity of input/output connections and external electronic circuitry while (2) using enough diodes to obtain the required precision. Optionally, to minimize spurious heating of the cryogenic fluid, the external circuitry can be designed to apply power to the probe only during brief measurement intervals. Assuming that the external circuitry is maintained at a steady temperature, a power-on interval of only a few seconds is sufficient to obtain accurate data on temperatures and/or the height of the liquid/vapor interface.

  12. Observations and modeling of exchange and residence time in tidal inlets

    NASA Astrophysics Data System (ADS)

    Rynne, Patrick Forde

    also developed. In the transport model, a new definition of tidally driven exchange is presented and used to quantify how tidal exchange controls residence time in a lagoon. Residence time is found to be minimized for inlets that are restricted enough to produce energetic tidal flows, but broad enough to prevent a reduction in the tidal prism. To apply the methods derived from the idealized modeling to a real inlet system, a depth-averaged coupled Wave-Flow model of New River Inlet (NRI) in North Carolina is developed. NRI features a relatively narrow inlet that connects to an expansive estuary. The model is calibrated and verified with a collection of field observations obtained during the first ONR funded Inlet and River Mouth Dynamics Departmental Research Initiative (RIVET 1) field experiment. In situ flow, water level, wave and dye concentration observations are used to quantify model performance through a skill analysis. The methods developed to quantify residence time and tidal exchange in the idealized lagoon models are applied to the NRI model. The model is used to quantify residence time with parameters from each tidal cycle from May 1-20, 2012 to examine temporal variability. Through the modeling it is shown that residence time in an estuary is controlled primarily by the geometry of the system, and by the processes of tidal exchange and river flushing. Tidal exchange is further controlled by an assortment of factors including the geometry of the inlet, the magnitude of the tide, and any physical processes that draw water away from the inlet on both the ocean and estuary sides. The temporal variability of tidal exchange is attributed primarily to subtidal fluctuations of the tidal prism and secondarily to nearshore processes driven by wind and waves that produce longshore currents. The river flow at NRI, although weak, is shown to reduce the mean residence time by 14.6%. Future work is needed to develop an analytical expression for the mean residence time in

  13. Test Analysis Correlation of the Single Stringer Bending Tests for the Space Shuttle ET-137 Intertank Stringer Crack Investigation

    NASA Technical Reports Server (NTRS)

    Phillips, Dawn R.; Saxon, Joseph B.; Wingate, Robert J.

    2012-01-01

    On November 5, 2010, Space Shuttle mission STS-133 was scrubbed due to a hydrogen leak at the Ground Umbilical Carrier Plate (GUCP). After the scrub, a crack in the foam thermal protection system (TPS) was observed on the External Tank (ET) near the interface between the liquid oxygen (LOX) tank and the Intertank. When the damaged foam was removed, two 9-in. long cracks were found on the feet of Intertank stringer S7-2, and the stringer failure was the cause of the TPS crack. An investigation was conducted to determine the root cause of the cracks, establish a remedy/repair for the stringers, and provide flight rationale for the damaged tank, ET-137. The Space Transportation System (STS) Super Lightweight ET (SLWT) is comprised of two propellant tanks (an aft liquid hydrogen (LH2) tank and a forward LOX tank) and an Intertank. The Intertank serves as the structural connection between the two propellant tanks and also functions to receive and distribute all thrust loads from the solid rocket boosters . The Intertank is a stiffened cylinder structure consisting of eight mechanically joined panels (two integrally-stiffened, machined thrust panels to react the booster loads and six stringer-stiffened skin panels). There are one main ring frame, four intermediate ring frames, and forward and aft flange chords that mate to the respective propellant tanks.. The skin/stringer panels utilize external hat-section stringers that are mechanically attached with rivets along most of their length and with specialty fasteners, such as GP Lockbolts and Hi-Loks, at the forward and aft ends where the stringers attach to the flange chords. During the STS-133 Intertank stringer crack investigation, cracks were found on a total of five stringers. All of the cracks were at the LOX end, in the feet of the stringers, and near the forward fasteners (GP Lockbolts). Video of tanking for the November 5 launch attempt was used to determine that the TPS failure, and thus the stringer failure

  14. Leveraging Data Intensive Computing to Support Automated Event Services

    NASA Technical Reports Server (NTRS)

    Clune, Thomas L.; Freeman, Shawn M.; Kuo, Kwo-Sen

    2012-01-01

    A large portion of Earth Science investigations is phenomenon- or event-based, such as the studies of Rossby waves, mesoscale convective systems, and tropical cyclones. However, except for a few high-impact phenomena, e.g. tropical cyclones, comprehensive records are absent for the occurrences or events of these phenomena. Phenomenon-based studies therefore often focus on a few prominent cases while the lesser ones are overlooked. Without an automated means to gather the events, comprehensive investigation of a phenomenon is at least time-consuming if not impossible. An Earth Science event (ES event) is defined here as an episode of an Earth Science phenomenon. A cumulus cloud, a thunderstorm shower, a rogue wave, a tornado, an earthquake, a tsunami, a hurricane, or an EI Nino, is each an episode of a named ES phenomenon," and, from the small and insignificant to the large and potent, all are examples of ES events. An ES event has a finite duration and an associated geolocation as a function of time; its therefore an entity in four-dimensional . (4D) spatiotemporal space. The interests of Earth scientists typically rivet on Earth Science phenomena with potential to cause massive economic disruption or loss of life, but broader scientific curiosity also drives the study of phenomena that pose no immediate danger. We generally gain understanding of a given phenomenon by observing and studying individual events - usually beginning by identifying the occurrences of these events. Once representative events are identified or found, we must locate associated observed or simulated data prior to commencing analysis and concerted studies of the phenomenon. Knowledge concerning the phenomenon can accumulate only after analysis has started. However, except for a few high-impact phenomena. such as tropical cyclones and tornadoes, finding events and locating associated data currently may take a prohibitive amount of time and effort on the part of an individual investigator. And

  15. ldentifying Episodes of Earth Science Phenomena Using a Big-Data Technology

    NASA Technical Reports Server (NTRS)

    Kuo, Kwo-Sen; Oloso, Amidu; Rushing, John; Lin, Amy; Fekete, Gyorgy; Ramachandran, Rahul; Clune, Thomas; Dunny, Daniel

    2014-01-01

    A significant portion of Earth Science investigations is phenomenon- (or event-) based, such as the studies of Rossby waves, volcano eruptions, tsunamis, mesoscale convective systems, and tropical cyclones. However, except for a few high-impact phenomena, e.g. tropical cyclones, comprehensive records are absent for the occurrences or events of these phenomena. Phenomenon-based studies therefore often focus on a few prominent cases while the lesser ones are overlooked. Without an automated means to gather the events, comprehensive investigation of a phenomenon is at least time-consuming if not impossible. We have constructed a prototype Automated Event Service (AES) system that is used to methodically mine custom-defined events in the reanalysis data sets of atmospheric general circulation models. Our AES will enable researchers to specify their custom, numeric event criteria using a user-friendly web interface to search the reanalysis data sets. Moreover, we have included a social component to enable dynamic formation of collaboration groups for researchers to cooperate on event definitions of common interest and for the analysis of these events. An Earth Science event (ES event) is defined here as an episode of an Earth Science phenomenon (ES phenomenon). A cumulus cloud, a thunderstorm shower, a rogue wave, a tornado, an earthquake, a tsunami, a hurricane, or an El Nino, is each an episode of a named ES phenomenon, and, from the small and insignificant to the large and potent, all are examples of ES events. An ES event has a duration (often finite) and an associated geo-location as a function of time; it's therefore an entity embedded in four-dimensional (4D) spatiotemporal space. Earth Science phenomena with the potential to cause massive economic disruption or loss of life often rivet the attention of researchers. But, broader scientific curiosity also drives the study of phenomena that pose no immediate danger, such as land/sea breezes. Due to Earth System

  16. Nickel and cobalt allergy before and after nickel regulation--evaluation of a public health intervention.

    PubMed

    Thyssen, Jacob Pontoppidan

    2011-09-01

    Over the 20th century, the frequent use of nickel in consumer products resulted in an increasing prevalence of nickel allergy. Risk items included suspenders in the 1950s-1960s; buttons, zippers and rivets in the 1970s; and ear-piercing jewellery in the 1980s. When subjects allergic to nickel were exposed to nickel in high concentrations, it often resulted in allergic nickel contact dermatitis and hand eczema. In 1990, the Danish government began to regulate consumer nickel exposure as a response to the increasing nickel allergy problem. In 1994, the EU Nickel Directive was passed, a regulation that was based on the Danish and Swedish nickel regulations. These major public health interventions were expected to change the epidemiology of nickel allergy and dermatitis in Europe. Furthermore, it was debated whether nickel would be replaced by cobalt in inexpensive jewellery and result in higher prevalence of cobalt allergy. An evaluation of the possible effects of the European nickel regulations is of importance to ensure protection of consumers and dermatitis patients. This doctoral thesis aimed to evaluate the effects of regulatory interventions on nickel exposure by investigating the development of nickel allergy and dermatitis before and after nickel regulation. Furthermore, a change in the association between nickel allergy and hand eczema was evaluated. The nickel spot test was validated to determine its value when used for screening purposes. Possible explanations for the persistence of nickel allergy were explored including genetic predisposition and consumer nickel exposure from jewellery and accessories. A cobalt spot test was developed and validated. Finally, it was evaluated whether a cobalt allergy epidemic had replaced the nickel allergy epidemic after nickel regulation in terms of increasing cobalt sensitization and cobalt exposure. The thesis showed that the prevalence of nickel allergy decreased significantly after nickel regulation in young Danish

  17. Modal content based damage indicators and phased array transducers for structural health monitoring of aircraft structures using ultrasonic guided waves

    NASA Astrophysics Data System (ADS)

    Ren, Baiyang

    Composite materials, especially carbon fiber reinforced polymers (CFRP), have been widely used in the aircraft industry because of their high specific strength and stiffness, resistance to corrosion and good fatigue life. Due to their highly anisotropic material properties and laminated structures, joining methods like bolting and riveting are no longer appropriate for joining CFRP since they initiate defects during the assembly and severely compromise the integrity of the structure; thus new techniques for joining CFRP are highly demanded. Adhesive bonding is a promising method because it relieves stress concentration, reduces weight and provides smooth surfaces. Additionally, it is a low-cost alternative to the co-cured method which is currently used to manufacture components of aircraft fuselage. Adhesive defects, disbonds at the interface between adherend and adhesive layer, are focused on in this thesis because they can be initialized by either poor surface preparation during the manufacturing or fatigue loads during service. Aircraft need structural health monitoring (SHM) systems to increase safety and reduce loss, and adhesive bonds usually represent the hotspots of the assembled structure. There are many nondestructive evaluation (NDE) methods for bond inspection. However, these methods cannot be readily integrated into an SHM system because of the bulk size and weight of the equipment and requirement of accessibility to one side of the bonded joint. The first objective of this work is to develop instruments, actuators, sensors and a data acquisition system for SHM of bond lines using ultrasonic guided waves which are well known to be able to cover large volume of the structure and inaccessible regions. Different from widely used guided wave sensors like PZT disks, the new actuators, piezoelectric fiber composite (PFC) phased array transducers0 (PAT), can control the modal content of the excited waves and the new sensors, polyvinylidene fluoride (PVDF

  18. XB-70A #1 liftoff with TB-58A chase aircraft

    NASA Technical Reports Server (NTRS)

    1960-01-01

    .6-percent delta wing. The outer portion of the wing could be folded down in flight to provide greater lateral-directional stability. The airplane had two windshields. A moveable outer windshield was raised for high-speed flight to reduce drag and lowered for greater visibility during takeoff and landing. The forward fuselage was constructed of riveted titanium frames and skin. The remainder of the airplane was constructed almost entirely of stainless steel. The skin was a brazed stainless-steel honeycomb material. Six General Electric YJ93-3 turbojet engines, each in the 30,000-pound-thrust class, powered the XB-70. Internal geometry of the inlets was controllable to maintain the most efficient airflow to the engines.

  19. Flexible Cryogenic Temperature and Liquid-Level Probes

    NASA Technical Reports Server (NTRS)

    Haberbusch, Mark

    2003-01-01

    the designs of the probes and of associated external electronic circuitry. In each probe, the diodes and the lead wires are embedded in a strong, lightweight, flexible polyimide strip. Each probe is constructed as an integral unit that includes a multipin input/output plug or socket for solderless connection of the lead wires to the external circuitry. The polyimide strip includes mounting tabs with holes that can accommodate rivets, screws, or other fasteners. Alternatively, a probe can be mounted by use of an epoxy. A probe can be manufactured to almost any length or width, and the diodes can be embedded at almost any desired locations along and across the polyimide strip. In designing a probe for a specific application, one seeks a compromise between (1) minimizing the number of diodes in order to minimize the complexity of input/output connections and external electronic circuitry while (2) using enough diodes to obtain the required precision. Optionally, to minimize spurious heating of the cryogenic fluid, the external circuitry can be designed to apply power to the probe only during brief measurement intervals. Assuming that the external circuitry is maintained at a steady temperature, a power-on interval of only a few seconds is sufficient to obtain accurate data on temperatures and/or the height of the liquid/vapor interface.

  20. XB-70A #1 cockpit

    NASA Technical Reports Server (NTRS)

    1965-01-01

    was the world's largest experimental aircraft. It was capable of flight at speeds of three times the speed of sound (roughly 2,000 miles per hour) at altitudes of 70,000 feet. It was used to collect in-flight information for use in the design of future supersonic aircraft, military and civilian. The major objectives of the XB-70 flight research program were to study the airplane's stability and handling characteristics, to evaluate its response to atmospheric turbulence, and to determine the aerodynamic and propulsion performance. In addition there were secondary objectives to measure the noise and friction associated with airflow over the airplane and to determine the levels and extent of the engine noise during takeoff, landing, and ground operations. The XB-70 was about 186 feet long, 33 feet high, with a wingspan of 105 feet. Originally conceived as an advanced bomber for the United States Air Force, the XB-70 was limited to production of two aircraft when it was decided to limit the aircraft's mission to flight research. The first flight of the XB-70 was made on Sept. 21, 1964. The number two XB-70 was destroyed in a mid-air collision on June 8, 1966. Program management of the NASA-USAF research effort was assigned to NASA in March 1967. The final flight was flown on Feb. 4, 1969. Designed by North American Aviation (later North American Rockwell and still later, a division of Boeing) the XB-70 had a long fuselage with a canard or horizontal stabilizer mounted just behind the crew compartment. It had a sharply swept 65.6-percent delta wing. The outer portion of the wing could be folded down in flight to provide greater lateral-directional stability. The airplane had two windshields. A moveable outer windshield was raised for high-speed flight to reduce drag and lowered for greater visibility during takeoff and landing. The forward fuselage was constructed of riveted titanium frames and skin. The remainder of the airplane was constructed almost entirely of

  1. List of Participants

    NASA Astrophysics Data System (ADS)

    2011-09-01

    KhodelVictorKurchatov Institute, Moscowvak@wuphys.wustl.edu KimuraMasaakiHokkaido University, Sapporomasaaki@nucl.sci.hokudai.ac.jp LacroixDenisGANIL, Caenlacroix@ganil.fr LiangHaozhaoPeking University, Beijinghzliang@pku.edu.cn MargueronJérômeIPN Orsayjerome.margueron@ipno.in2p3.fr MassotElisabethIPN Orsaymassot@ipno.in2p3.fr MengJiePeking University, Beijingmengj@pku.edu.cn MillerTomaszWarsaw University of Technologymillert@student.mini.pw.edu.pl MoghrabiKassemIPN Orsaymoghrabi@ipno.in2p3.fr NapolitaniPaoloIPN Orsaynapolita@ipno.in2p3.fr NeffThomasGSI Darmstadtt.neff@gsi.de NguyenVan GiaiIPN Orsaynguyen@ipno.in2p3.fr OtsukaTakaharuUniversity of Tokyootsuka@phys.s.u-tokyo.ac.jp PilletNathalie-MarieCEA-DAM, Arpajonnathalie.pillet@cea.fr QiChongKTH Stockholmchongq@kth.se RamananSunethraICTP Triestesramanan@ictp.it RingPeterTU Munichring@ph.tum.de Rios HuguetArnauUniversity of Surreya.rios@surrey.ac.uk RivetMarie-FranceIPN Orsayrivet@ipno.in2p3.fr RobledoLuisUniversidad Autonoma de Madridluis.robledo@uam.es Roca MazaXavierINFN Milanoxavier.roca.maza@mi.infn.it RöpkeGerdRostock Universitygerd.roepke@uni-rostock.de RowleyNeilIPN Orsayrowley@ipno.in2p3.fr SagawaHiroyukiUniversity of Aizusagawa@u-aizu.ac.jp SandulescuNicolaeIFIN-HH, Bucharestsandulescu@theory.nipne.ro SchuckPeterIPN Orsayschuck@ipno.in2p3.fr SedrakianArmenGoethe Universität Frankfurtsedrakian@th.physik.uni-frankfurt.de SeveryukhinAlexeyJINR Dubnasever@theor.jinr.ru SogoTakaakiIPN Orsaysogo@ipno.in2p3.fr SomàVittorioCEA Saclayvittorio.soma@cea.fr StrinatiGiancarloUniversità di Camerinogiancarlo.strinati@gmail.com SuharaTadahiroKyoto Universitysuhara@ruby.scphys.kyoto-u.ac.jp SukhoruchkinSergeiPetersburg Nuclear Physics Institutesergeis@pnpi.spb.ru SuzukiToruTokyo Metropolitan Universitysuzukitr@tmu.ac.jp SuzukiToshioNihon University, Tokyosuzuki@chs.nihon-u.ac.jp TarpanovDimitarINRNE, Sofiadimitert@yahoo.co.uk Tohsaki-SuzukiAkihiroOsaka Universitytohsaki@rcnp.osaka-u.ac.jp TypelStefanGSI Darmstadts

  2. Distributed modeling of radiocesium washoff from the experimental watershed plots of the Fukushima fallout zone

    NASA Astrophysics Data System (ADS)

    Kivva, Sergei; Zheleznyak, Mark; Konoplev, Alexei; Nanba, Kenji; Onda, Yuichi; Wakiyama Yoshifumi Wakiyama, Yoshifumi

    2015-04-01

    watershed of Konoplyanka river, tributary of Dnieper Rivet at the territory of the Pridneprovsky Chemical) Plant and neighboring tailings dumps. The modeling results has been used for the assessment of the watershed's "hot spots" and analyses of the ways of the diminishing of the uranium wash off from the watersheds The testing of DHSMV-R has started in 2014 for Fukushima watershed experimental plots. The major amount of 137Cs is washed out from watershed on sediments and only small fraction in solute. The reason for such phenomenon that was not observed at Chernobyl can be - steeper slopes, more intensive rains ( daily maximum in Fukushima city at 160 mm, hourly maximum 69mm) and higher Kd values due to the volcanic kind of soils. The virtual rain of the daily amount 200 mm ( as in mountains around Fukushima city) was applied for Farmland A1- slope 7.36% and imaginary watershed (case B) the same as A1 however slope as in Chernobyl plots ( Konoplev, 1996) 4%. Due to the high nonlinearity in erosion equations for the such heavy precipitations the total amount of washed out 137Cs with sediments for the steep watershed A due to the simulated rainstorm ( 11530 Bq) is at 20 times higher, than such amount for mild slope watershed B ( 690 Bq) when the watershed A is only twice steeper than B. The modeling results demonstrate that the higher intensity of the extreme rainstorm in Fukushima area than in Chernobyl area initiated even on slightly steeper slopes the much higher amount of 137Cs washed out with sediments in Fukushima than in Chernobyl area. The successful testing of the distributed model provides the background for the simulation of the watersheds of the larger scales for small, medium and large rivers. The implementation of such models is important as for the forecasting of 137Cs wash out from the watersheds and following transport in rivers for the highest extreme floods that still did not happen in Fukushima area after the accident, as also for the long term