Sample records for y-joint test article

  1. Transient Pressure Test Article Test Program

    NASA Technical Reports Server (NTRS)

    Vibbart, Charles M.

    1989-01-01

    The Transient Pressure Test Article (TPTA) test program is being conducted at a new test facility located in the East Test Area at the National Aeronautics and Space Administration's (NASA's) Marshall Space Flight Center (MSFC) in Huntsville, Alabama. This facility, along with the special test equipment (STE) required for facility support, was constructed specifically to test and verify the sealing capability of the Redesigned Solid Rocket Motor (RSRM) field, igniter, and nozzle joints. The test article consists of full scale RSRM hardware loaded with inert propellant and assembled in a short stack configuration. The TPTA is pressurized by igniting a propellant cartridge capable of inducing a pressure rise rate which stimulates the ignition transient that occurs during launch. Dynamic loads are applied during the pressure cycle to simulate external tank attach (ETA) strut loads present on the ETA ring. Sealing ability of the redesigned joints is evaluated under joint movement conditions produced by these combined loads since joint sealing ability depends on seal resilience velocity being greater than gap opening velocity. Also, maximum flight dynamic loads are applied to the test article which is either pressurized to 600 psia using gaseous nitrogen (GN2) or applied to the test article as the pressure decays inside the test article on the down cycle after the ignition transient cycle. This new test facility is examined with respect to its capabilities. In addition, both the topic of test effectiveness versus space vehicle flight performance and new aerospace test techniques, as well as a comparison between the old SRM design and the RSRM are presented.

  2. Test and Analysis Correlation for a Y-Joint Specimen for a Composite Cryotank

    NASA Technical Reports Server (NTRS)

    Mason, Brian H.; Sleight, David W.; Grenoble, Ray

    2015-01-01

    The Composite Cryotank Technology Demonstration (CCTD) project under NASA's Game Changing Development Program (GCDP) developed space technologies using advanced composite materials. Under CCTD, NASA funded the Boeing Company to design and test a number of element-level joint specimens as a precursor to a 2.4-m diameter composite cryotank. Preliminary analyses indicated that the y-joint in the cryotank had low margins of safety; hence the y-joint was considered to be a critical design region. The y-joint design includes a softening strip wedge to reduce localized shear stresses at the skirt/dome interface. In this paper, NASA-developed analytical models will be correlated with the experimental results of a series of positive-peel y-joint specimens from Boeing tests. Initial analytical models over-predicted the experimental strain gage readings in the far-field region by approximately 10%. The over-prediction was attributed to uncertainty in the elastic properties of the laminate and a mismatch between the thermal expansion of the strain gages and the laminate. The elastic properties of the analytical model were adjusted to account for the strain gage differences. The experimental strain gages also indicated a large non-linear effect in the softening strip region that was not predicted by the analytical model. This non-linear effect was attributed to delamination initiating in the softening strip region at below 20% of the failure load for the specimen. Because the specimen was contained in a thermally insulated box during cryogenic testing to failure, delamination initiation and progression was not visualized during the test. Several possible failure initiation locations were investigated, and a most likely failure scenario was determined that correlated well with the experimental data. The most likely failure scenario corresponded to damage initiating in the softening strip and delamination extending to the grips at final failure.

  3. Optical Fiber Distributed Sensing Structural Health Monitoring (SHM) Strain Measurements Taken During Cryotank Y-Joint Test Article Load Cycling at Liquid Helium Temperatures

    NASA Technical Reports Server (NTRS)

    Allison, Sidney G.; Prosser, William H.; Hare, David A.; Moore, Thomas C.; Kenner, Winfred S.

    2007-01-01

    This paper outlines cryogenic Y-joint testing at Langley Research Center (LaRC) to validate the performance of optical fiber Bragg grating strain sensors for measuring strain at liquid helium temperature (-240 C). This testing also verified survivability of fiber sensors after experiencing 10 thermal cool-down, warm-up cycles and 400 limit load cycles. Graphite composite skins bonded to a honeycomb substrate in a sandwich configuration comprised the Y-joint specimens. To enable SHM of composite cryotanks for consideration to future spacecraft, a light-weight, durable monitoring technology is needed. The fiber optic distributed Bragg grating strain sensing system developed at LaRC is a viable substitute for conventional strain gauges which are not practical for SHM. This distributed sensing technology uses an Optical Frequency Domain Reflectometer (OFDR). This measurement approach has the advantage that it can measure hundreds of Bragg grating sensors per fiber and the sensors are all written at one frequency, greatly simplifying fiber manufacturing. Fiber optic strain measurements compared well to conventional strain gauge measurements obtained during these tests. These results demonstrated a high potential for a successful implementation of a SHM system incorporating LaRC's fiber optic sensing system on the composite cryotank and other future cryogenic applications.

  4. Assembly Test Article (ATA)

    NASA Technical Reports Server (NTRS)

    Ricks, Glen A.

    1988-01-01

    The assembly test article (ATA) consisted of two live loaded redesigned solid rocket motor (RSRM) segments which were assembled and disassembled to simulate the actual flight segment stacking process. The test assembly joint was flight RSRM design, which included the J-joint insulation design and metal capture feature. The ATA test was performed mid-November through 24 December 1987, at Kennedy Space Center (KSC), Florida. The purpose of the test was: certification that vertical RSRM segment mating and separation could be accomplished without any damage; verification and modification of the procedures in the segment stacking/destacking documents; and certification of various GSE to be used for flight assembly and inspection. The RSRM vertical segment assembly/disassembly is possible without any damage to the insulation, metal parts, or seals. The insulation J-joint contact area was very close to the predicted values. Numerous deviations and changes to the planning documents were made to ensure the flight segments are effectively and correctly stacked. Various GSE were also certified for use on flight segments, and are discussed in detail.

  5. Ground test article for deployable space structure systems

    NASA Technical Reports Server (NTRS)

    Malloy, G. D.

    1984-01-01

    The ground test article fabrication and assembly plan was completed by Santek Engineering, Inc. The plan was reviewed and accepted by Rockwell during an on-site visit to the Santek facility. Raw material and hardware orders were placed by Santek in July. Approximately 98% of the raw materials and 10% of the hardware deliveries have been completed. Several material and hardware substitutions were requested by Santek due to no-bid responses from suppliers or excessive costs for limited quantity items. These substitutions were evaluated and approved by Rockwell Engineering and Material and Process and are being incorporated into the drawing package. Santek started fabrication of detail parts in mid-August. Their current resource utilization is at approximately 50% of the planned eventual commitment and is increasing at a rate commensurate with the fabrication and assembly plan. At this writing, Santek's estimate of completion is 03%. During verification testing of the diagonal member joint, in a program funded by Rockwell discretionary funds, the axial load to unlock the joint was found to increase significantly after a few cycles of operation. This was attributed to galling, poor lubrication, and locking pin geometry. A change of materials, lubricant, and modification of the pin geometry reduced the unlocking load and provided repeatability after 50 cycles of operation. This new design is being implemented into the ground test article.

  6. Determination of Parachute Joint Factors using Seam and Joint Testing

    NASA Technical Reports Server (NTRS)

    Mollmann, Catherine

    2015-01-01

    This paper details the methodology for determining the joint factor for all parachute components. This method has been successfully implemented on the Capsule Parachute Assembly System (CPAS) for the NASA Orion crew module for use in determining the margin of safety for each component under peak loads. Also discussed are concepts behind the joint factor and what drives the loss of material strength at joints. The joint factor is defined as a "loss in joint strength...relative to the basic material strength" that occurs when "textiles are connected to each other or to metals." During the CPAS engineering development phase, a conservative joint factor of 0.80 was assumed for each parachute component. In order to refine this factor and eliminate excess conservatism, a seam and joint testing program was implemented as part of the structural validation. This method split each of the parachute structural joints into discrete tensile tests designed to duplicate the loading of each joint. Breaking strength data collected from destructive pull testing was then used to calculate the joint factor in the form of an efficiency. Joint efficiency is the percentage of the base material strength that remains after degradation due to sewing or interaction with other components; it is used interchangeably with joint factor in this paper. Parachute materials vary in type-mainly cord, tape, webbing, and cloth -which require different test fixtures and joint sample construction methods. This paper defines guidelines for designing and testing samples based on materials and test goals. Using the test methodology and analysis approach detailed in this paper, the minimum joint factor for each parachute component can be formulated. The joint factors can then be used to calculate the design factor and margin of safety for that component, a critical part of the design verification process.

  7. Transient Pressure Test Article (TPTA) 1.1 and 1.1A, volume 1

    NASA Technical Reports Server (NTRS)

    Rebells, Clarence A.

    1988-01-01

    This final test report presents the results obtained during the static hot firing and cold-gas high Q tests of the first Transient Pressure Test Article (TPTA) 1.1. The TPTA consisted of field test joints A and B, which were the original RSRM J-insulation configuration, with a metal capture feature. It also consisted of a flight configuration nozzle-to-case test joint (Joint D) with shorter vent slots. Fluorocarbon O-rings were used in all the test joints. The purpose of the TPTA tests is to evaluate and characterize the RSMR field and nozzle-to-case joints under the influence of ignition and strut loads during liftoff anf high Q. All objectives of the cold-gas high Q (TPTA 1.1A) test were met and all measurements were close to predicted values. During the static hot-firing test (TPTA 1.1), the motor was inadvertently plugged by the quench injector plug, making it a more severe test, although no strut loads were applied. The motor was depressurized after approximately 11 min using an auxiliary system, and no anomalies were noted. In the static hot-firing test, pressure was incident on the insulation and the test joint gaps were within the predicted range. During the static hot-firing test, no strut loads were applied because the loading system malfunctioned. For this test, all measurements were within range of similar tests performed without strut loads.

  8. Field joint protection system rain qualification test report

    NASA Technical Reports Server (NTRS)

    Cook, M.

    1989-01-01

    This report documents the procedures, performance, and results obtained from the Field Joint Protection System (FJPS) rain test. This test was performed to validate that the flight configuration FJPS prevents the accumulation of moisture in the redesigned solid rocket motor (RSRM) field joints when subjected to simulated prelaunch natural rain environments. The FJPS test article was exposed to rain simulation for approximately 50 minutes. During the test, water entered through the open upper end of the systems tunnel and was funneled down between the tunnel and case. A sealant void at the moisture seal butt splice allowed this water to flow underneath the FJPS. The most likely cause of voids was improper bondline preparation, particularly on the moisture seal surface. In total, water penetrated underneath approximately 60 percent of the FJPS circumference. Because the test article was substantially different from flight configuration (no systems tunnel closeout), results of this test will not affect current flight motors. Due to the omission of systems tunnel covers and systems tunnel floor plate closeout, the test assembly was not representative of flight hardware and resulted in a gross overtest. It is therefore recommended that the test be declared void. It is also recommended that the test be repeated with a complete closeout of the systems tunnel, sealed systems tunnel ends, and improved adhesive bondline preparation.

  9. Materials testing protocol for small joint prostheses.

    PubMed

    Savory, K M; Hutchinson, D T; Bloebaum, R

    1994-10-01

    In this article, a protocol for the evaluation of new materials for small joint prostheses is introduced. The testing methods employed in the protocol were developed by reviewing reported clinical failure modes and conditions found in vivo. The methods developed quantitatively evaluates the fatigue, fatigue crack propagation, and wear resistance properties of materials. For this study, a silicone elastomer similar to Dow Corning Silastic HP100, a radiation stable polypropylene, and a copolymer of polypropylene and ethylene propylene-diene monomer (EPDM) are evaluated. None of the materials tested demonstrated the ideal properties that are sought in a self-hinging joint prostheses. The silicone elastomer had excellent wear properties; however, cracks quickly propagated, causing catastrophic failure when fatigued. Conversely, the copolymer showed excellent fatigue crack propagation resistance and less than favorable wear properties. The polypropylene did not perform well in any evaluation.

  10. CRYogenic Orbital TEstbed Ground Test Article Thermal Analysis

    NASA Technical Reports Server (NTRS)

    Piryk, David; Schallhorn, Paul; Walls, Laurie; Stopnitzky, Benny; Rhys, Noah; Wollen, Mark

    2012-01-01

    The purpose of this study was to anchor thermal and fluid system models to CRYOTE ground test data. The CRYOTE ground test artide was jointly developed by Innovative Engineering Solutions, United Launch Alliance and NASA KSC. The test article was constructed out of a titanium alloy tank, Sapphire 77 composite skin (similar to G10), an external secondary payload adapter ring, thermal vent system, multi layer insulation and various data acquisition instrumentation. In efforts to understand heat loads throughout this system, the GTA (filled with liquid nitrogen for safety purposes) was subjected to a series of tests in a vacuum chamber at Marshall Space Flight Center. By anchoring analytical models against test data, higher fidelity thermal environment predictions can be made for future flight articles which would eventually demonstrate critical cryogenic fluid management technologies such as system chilldown, transfer, pressure control and long term storage. Significant factors that influenced heat loads included radiative environments, multi-layer insulation performance, tank fill levels and pressures and even contact conductance coefficients. This report demonstrates how analytical thermal/fluid networks were established and includes supporting rationale for specific thermal responses.

  11. SRB Environment Evaluation and Analysis. Volume 2: RSRB Joint Filling Test/Analysis Improvements

    NASA Technical Reports Server (NTRS)

    Knox, E. C.; Woods, G. Hamilton

    1991-01-01

    Following the Challenger accident a very comprehensive solid rocket booster (SRB) redesign program was initiated. One objective of the program was to develop expertise at NASA/MSFC in the techniques for analyzing the flow of hot gases in the SRB joints. Several test programs were undertaken to provide a data base of joint performance with manufactured defects in the joints to allow hot gases to fill the joints. This data base was used also to develop the analytical techniques. Some of the test programs were Joint Environment Simulator (JES), Nozzle Joint Environment Simulator (NJES), Transient Pressure Test Article (TPTA), and Seventy-Pound Charge (SPC). In 1988 the TPTA test hardware was moved from the Utah site to MSFC and several RSRM tests were scheduled, to be followed by tests for the ASRM program. REMTECH Inc. supported these activities with pretest estimates of the flow conditions in the test joints, and post-test analysis and evaluation of the measurements. During this support REMTECH identified deficiencies in the gas-measurement instrumentation that existed in the TPTA hardware, made recommendations for its replacement, and identified improvements to the analytical tools used in the test support. Only one test was completed under the TPTA RSRM test program, and those scheduled for the ASRM were rescheduled to a time after the expiration of this contract. The attention of this effort was directed toward improvements in the analytical techniques in preparation for when the ASRM program begins.

  12. The Joint Convention - Its Structure, the Articles and its Administration

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Metcalf, P.; Louvat, D.

    The objective of the Joint Convention on the Safety of Spent Fuel Management and on the Safety of Radioactive Waste Management (The Joint Convention) is to achieve a high level of safety worldwide in the management of spent nuclear and fuel and radioactive waste. [1] It is an incentive convention designed to encourage and assist countries to achieve the objective. Contracting Parties to the Joint Convention are required to compile and submit a national report on how they meet the articles of the Joint Convention. The reports are peer reviewed by other Contracting Parties to the Joint Convention and thenmore » countries have to defend the report at a review meeting of all the Contracting Parties. The process entails both a self appraisal in compiling the report and independent international peer review. Summaries are compiled of the various reviews and these are presented in plenary, with a view to identifying generic issues and areas in which countries are improving safety or have identified for further development. The process also presents an opportunity for countries involved to benchmark their national spent fuel and radioactive waste safety programmes against prevailing international practice. The paper elaborates the detailed elements involved and discusses the experience from the first review meeting of Contracting Parties, and issues envisaged for consideration at the second review meeting scheduled for May 2006. (authors)« less

  13. Critical joints in large composite primary aircraft structures. Volume 2: Technology demonstration test report

    NASA Technical Reports Server (NTRS)

    Bunin, Bruce L.

    1985-01-01

    A program was conducted to develop the technology for critical structural joints in composite wing structure that meets all the design requirements of a 1990 commercial transport aircraft. The results of four large composite multirow bolted joint tests are presented. The tests were conducted to demonstrate the technology for critical joints in highly loaded composite structure and to verify the analytical methods that were developed throughout the program. The test consisted of a wing skin-stringer transition specimen representing a stringer runout and skin splice on the wing lower surface at the side of the fuselage attachment. All tests were static tension tests. The composite material was Toray T-300 fiber with Ciba-Geigy 914 resin in 10 mil tape form. The splice members were metallic, using combinations of aluminum and titanium. Discussions are given of the test article, instrumentation, test setup, test procedures, and test results for each of the four specimens. Some of the analytical predictions are also included.

  14. STRUCTURAL TEST ARTICLE

    NASA Image and Video Library

    2016-04-06

    FROM RIGHT, KATHRYN GUELDE AND ASHLEY HOLLADAY OF AERIE AEROSPACE LLC IN HUNTSVILLE, INSTALL THE STRUCTURAL TEST ARTICLE FOR THE FIRST SERIES OF COMPOSITE TESTS FOR THE SHELL BUCKLING KNOCKDOWN FACTOR PROJECT.

  15. Space Suit Joint Torque Testing

    NASA Technical Reports Server (NTRS)

    Valish, Dana J.

    2011-01-01

    In 2009 and early 2010, a test was performed to quantify the torque required to manipulate joints in several existing operational and prototype space suits in an effort to develop joint torque requirements appropriate for a new Constellation Program space suit system. The same test method was levied on the Constellation space suit contractors to verify that their suit design meets the requirements. However, because the original test was set up and conducted by a single test operator there was some question as to whether this method was repeatable enough to be considered a standard verification method for Constellation or other future space suits. In order to validate the method itself, a representative subset of the previous test was repeated, using the same information that would be available to space suit contractors, but set up and conducted by someone not familiar with the previous test. The resultant data was compared using graphical and statistical analysis and a variance in torque values for some of the tested joints was apparent. Potential variables that could have affected the data were identified and re-testing was conducted in an attempt to eliminate these variables. The results of the retest will be used to determine if further testing and modification is necessary before the method can be validated.

  16. Neuropeotide Y changes the excitability of fine afferent units in the rat knee joint

    PubMed Central

    Just, Stefan; Heppelmann, Bernd

    2001-01-01

    The aim of the present study was to examine the effects of the sympathetic co-transmitter Neuropeotide Y on primary afferent nerve fibres of the rat knee joint. The responses to passive joint rotations at defined torque were recorded from 41 slowly conducting afferent nerve fibres (0.9 – 18.8 m s−1) innervating the knee joint capsule. About 70% of the joint afferents were significantly affected in their mechanosensitivity by topical application of Neuropeptide Y. Significant effects occurred at a concentration of 10 nM. Decreased mechanosensitivity was observed in about 40% of nerve fibres, whereas 30% of the units increased the mechanosensitivity. In addition, in about 35% of the fibres resting activity was induced or increased. Neither the conduction velocity nor the mechanical threshold of the units correlated with the described effects of Neuropeptide Y. NPY(13 – 36), a specific Y2-receptor agonist, only modulated the mechanosensitivity, with no effect on the resting activity. The effects on the mechanosensitivity were similar to Neuropeptide Y, i.e. increase and decrease of the response. Studies with the Y1-agonist (Leu31, Pro34)-NPY showed that activation of the Y1-receptor predominantly resulted in an enhanced mechanosensitivity and an induction or increase of a resting activity. The opposite effect was observed by application of BIBP 3226 BS, a Y1-receptor antagonist. In conclusion, these data indicate that Neuropeptide Y affects the excitability of sensory nerve fibre endings. PMID:11159723

  17. The design and development of a triaxial wear-testing joint simulator.

    PubMed

    Green, A S; O'Connell, M K; Lyons, A S; James, S P

    1999-01-01

    Most of the existing wear testers created to wear test total hip replacements, specifically the acetabular component, are designed to exert only an axial force and provide rotation in a close approximation of the actual femoral movement. The Rocky Mountain Joint Simulator was designed to exert three orthogonal forces and provide rotations about the X-, Y- and Z-axes to more closely simulate the physiological forces and motions found in the human gait cycle. The RMJS was also designed with adaptability for other joints, such as knees or canine hips, through the use of hydraulics and a computer-programmable control system. Such adaptability and functionality allows the researcher to more closely model a gait cycle, thereby obtaining wear patterns that resemble those found in retrieved implants more closely than existing simulators. Research is ongoing into the tuning and evaluation of the machine and preliminary acetabular component wear test results will be presented at the conference.

  18. Culture - joint fluid

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003742.htm Culture - joint fluid To use the sharing features on this page, please enable JavaScript. Joint fluid culture is a laboratory test to detect infection-causing ...

  19. Shading aboveground L-joint and lap-joint tests : comparison of white pine and sugar maple test assemblies

    Treesearch

    Carol A. Clausen; Daniel L. Lindner

    2011-01-01

    Five-year performance ratings are presented for two types of untreated, uncoated wood joints (L and lap) in aboveground tests under shaded conditions. The effect of shading on moisture entrapment in pine and maple L and lap joints was evaluated in a moderate decay zone (Madison, Wisconsin). Variations were observed between wood species, visual ratings, joint type,...

  20. Results and Analysis from Space Suit Joint Torque Testing

    NASA Technical Reports Server (NTRS)

    Matty, Jennifer

    2010-01-01

    This joint mobility KC lecture included information from two papers, "A Method for and Issues Associated with the Determination of Space Suit Joint Requirements" and "Results and Analysis from Space Suit Joint Torque Testing," as presented for the International Conference on Environmental Systems in 2009 and 2010, respectively. The first paper discusses historical joint torque testing methodologies and approaches that were tested in 2008 and 2009. The second paper discusses the testing that was completed in 2009 and 2010.

  1. Room Temperature and Elevated Temperature Composite Sandwich Joint Testing

    NASA Technical Reports Server (NTRS)

    Walker, Sandra P.

    1998-01-01

    Testing of composite sandwich joint elements has been completed to verify the strength capacity of joints designed to carry specified running loads representative of a high speed civil transport wing. Static tension testing at both room and an elevated temperature of 350 F and fatigue testing at room temperature were conducted to determine strength capacity, fatigue life, and failure modes. Static tension test results yielded failure loads above the design loads for the room temperature tests, confirming the ability of the joint concepts tested to carry their design loads. However, strength reductions as large as 30% were observed at the elevated test temperature, where all failure loads were below the room temperature design loads for the specific joint designs tested. Fatigue testing resulted in lower than predicted fatigue lives.

  2. Main Propulsion Test Article (MPTA)

    NASA Technical Reports Server (NTRS)

    Snoddy, Cynthia

    2010-01-01

    Scope: The Main Propulsion Test Article integrated the main propulsion subsystem with the clustered Space Shuttle Main Engines, the External Tank and associated GSE. The test program consisted of cryogenic tanking tests and short- and long duration static firings including gimbaling and throttling. The test program was conducted on the S1-C test stand (Position B-2) at the National Space Technology Laboratories (NSTL)/Stennis Space Center. 3 tanking tests and 20 hot fire tests conducted between December 21 1 1977 and December 17, 1980 Configuration: The main propulsion test article consisted of the three space shuttle main engines, flightweight external tank, flightweight aft fuselage, interface section and a boilerplate mid/fwd fuselage truss structure.

  3. Solid Propellant Test Article (SPTA) Test Stand

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This photograph shows the Solid Propellant Test Article (SPTA) test stand with the Modified Nasa Motor (M-NASA) test article at the Marshall Space Flight Center (MSFC). The SPTA test stand, 12-feet wide by 12-feet long by 24-feet high, was built in 1989 to provide comparative performance data on nozzle and case insulation material and to verify thermostructural analysis models. A modified NASA 48-inch solid motor (M-NASA motor) with a 12-foot blast tube and 10-inch throat makes up the SPTA. The M-NASA motor is being used to evaluate solid rocket motor internal non-asbestos insulation materials, nozzle designs, materials, and new inspection techniques. New internal motor case instrumentation techniques are also being evaluated.

  4. Joint Detect and Avoid Flight Testing

    NASA Technical Reports Server (NTRS)

    Maliska, Heather; Estrada, Ramon; Euteneuer, Eric; Gong, Chester; Arthur, Keith

    2015-01-01

    This presentation gives insight into a joint flight testing effort that included participation from NASA, Honeywell, and General Atomics. The presentation includes roles and responsibilities, test flow, and encounter requirements and summary.

  5. Utilization survey of prototype structural test article

    NASA Technical Reports Server (NTRS)

    Baber, S.; Mcdaniel, H. M.; Berry, M. J.

    1974-01-01

    A survey was conducted of six aerospace companies and two NASA agencies to determine how prototype structural test articles are used in flight operations. The prototype structures are airframes and similar devices which are used for testing and generally are not flown. The survey indicated the following: (1) prototype test articles are not being discarded after development testing is complete, but are used for other purposes, (2) only two cases of prototypes being refurbished and flown were identified, (3) protective devices and inspection techniques are available to prevent or minimize test article damage, (4) substitute programs from design verification are availabel in lieu of using prototype structural articles, and (5) there is a trend away from dedicated test articles. Four options based on these study results were identified to reduce test and hardware costs without compromising reliability of the flight program.

  6. [Diagnostic test scale SI5: Assessment of sacroiliac joint dysfunction].

    PubMed

    Acevedo González, Juan C; Quintero Oliveros, Silvia

    2015-01-01

    Sacroiliac joint dysfunction is a known cause of low back pain. We think that a diagnostic score scale (SI5) may be performed to assess diagnostic utility of clinical signs of sacroiliac joint dysfunction. The primary aim of the present study was to conduct the pilot study of our new diagnostic score scale, the SI5, for sacroiliac joint syndrome. We reviewed the literature on clinical characteristics, diagnostic tests and imaging most commonly used in diagnosing sacroiliac joint dysfunction. Our group evaluated the diagnostic utility of these aspects and we used those considered most representative to develop the SI5 diagnostic scale. The SI5 scale was applied to 22 patients with low back pain; afterwards, the standard test for diagnosing this pathology (selective blockage of the SI joint) was also performed on these patients. The sensitivity and specificity for each sign were also assessed and the diagnostic scale called SI5 was then proposed, based on these data. The most sensitive clinical tests for diagnosing SI joint dysfunction were 2 patient-reported clinical characteristics, the Laguerre Test, sacroiliac rocking test and Yeomans test (greater than 80% sensitivity). The tests with greatest diagnostic specificity (>80%) were the Lewitt test, Piedallu test and Gillet test. The proposed SI5 test score scale showed sensitivity of 73% and specificity of 71%. Sacroiliac joint syndrome has been shown to produce low back pain frequently; however, the diagnostic value of examination tests for sacroiliac joint pain has been questioned by other authors. The pilot study on the SI5 diagnostic score scale showed good sensitivity and specificity. However, the process of statistical validation of the SI5 needs to be continued. Copyright © 2014 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

  7. 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.

  8. Evaluation of Physical Examination Tests for Thumb Basal Joint Osteoarthritis

    PubMed Central

    Model, Zina; Liu, Andrew Y.; Kang, Lana; Wolfe, Scott W.; Burket, Jayme C.; Lee, Steve K.

    2016-01-01

    Background: We compare the ability of 3 diagnostic tests to reproduce the pain of basilar joint arthritis (BJA): the grind test, the lever test (grasping the first metacarpal just distal to the basal joint and shucking back and forth in radial and ulnar directions), and the metacarpophalangeal extension test. Methods: Sixty-two patients with thumb BJA were enrolled. The 3 tests were performed in a random order on both hands of each patient. Prior to testing, patients reported their typical pain level and subsequently rated their pain after each test on a 0 to 10 scale, also specifying the extent to which the test reproduced their thumb pain (fully, partially, not at all). All patients had radiographs that displayed basal joint arthritis. A test was defined as positive for BJA if pain produced was greater than 0. Sensitivity and specificity for each test were calculated using the patients’ history of pain localized to the basal joint and BJA diagnosis on radiographs as the gold standard. Results: The lever test produced the greatest level of pain and best reproduced the presenting pain. The lever test also had the highest sensitivity, high specificity, and the lowest false-negative rate. The grind test had the lowest sensitivity, highest specificity, and highest false-negative rate. Conclusions: The lever test was the diagnostic test that best reproduced the pain caused by thumb basal joint osteoarthritis. We recommend using the lever physical examination test when evaluating the patient with suspected basal joint osteoarthritis. The often-quoted grind test is of limited diagnostic value. PMID:27418899

  9. [Eosin Y-water test for sperm function examination].

    PubMed

    Zha, Shu-wei; Lü, Nian-qing; Xu, Hao-qin

    2015-06-01

    Based on the principles of the in vitro staining technique, hypotonic swelling test, and water test, the Eosin Y-water test method was developed to simultaneously detect the integrity of the sperm head and tail and sperm membrane structure and function. As a widely used method in clinical laboratories in China, the Eosin Y-water test is methodologically characterized by three advantages. Firstly, both the sperm head and tail can be detected at the same time, which allows easy and comprehensive assessment of membrane damage in different parts of sperm. Secondly, distilled water is used instead of the usual formula solution to simplify and standardize the test by eliminating any potential effects on the water molecules through the sperm membrane due to different osmotic pressure or different sugar proportions and electrolyte solutions. Thirdly, the test takes less time and thus can be repeated before and after treatment. This article focuses on the fundamental principles and modification of the Eosin Y-water test and its application in sperm function examination and routine semen analysis for male infertility, assessment of the quality of sperm retrieved by testicular fine needle aspiration, semen cryopreservation program development, and evaluation of sperm membrane integrity after microwave radiation.

  10. Lamb wave propagation in Z-pin reinforced co-cured composite pi-joints

    NASA Astrophysics Data System (ADS)

    Swenson, Eric D.; Soni, Som R.; Kapoor, Hitesh

    2010-04-01

    This paper presents an initial study on Lamb wave propagation characteristics in z-pin reinforced, co-cured composite pi-joints for the purposes of structural health monitoring (SHM). Pi-joint test articles were designed and created to replicate a co-cured, all composite skin-spar joint found within a typical aircraft wing structure. Because pi-joints exhibit various complex damage modes, formal studies are required if SHM systems are to be developed to monitor these types of joints for potential damage. Experiments were conducted on a undamaged (healthy) and damaged test articles where Lamb waves were excited using one lead zirconate titanate (PZT) transducer. A three-dimensional (3D) scanning laser Doppler vibrometer (LDV) was used to collect high-density scans of both the in-plane and out-of-plane velocity measurements. In the damaged test article, where delamination, matrix cracking, and fiber breakage can clearly be seen, changes in both the fundamental antisymmetric A0 and symmetric S0 Lamb wave modes are apparent. In both test articles, the effects of narrow geometry, discontinuity due to the attachment of the web, and thickness has detectable effects on Lamb wave propagation. From the comparisons between Lamb waves propagating through the undamaged and damaged test articles, it is clear that damage can be detected using Lamb waves in z-pin reinforced, co-cured composite pi-joints for this case of extensive damage.

  11. Screening Adhesively Bonded Single-Lap-Joint Testing Results Using Nonlinear Calculation Parameters

    DTIC Science & Technology

    2012-03-01

    versus displacement response for single-lap-joints bonded with damage-tolerant adhe- sives, such the polyurea adhesive plotted in Figure 2, is much...displacement response for a single-lap-joint bonded with a polyurea adhesive. Complex x-y plots are commonly fitted using the Levenberg-Marquardt...expected decrease in maximum strength for the polyurea in compar- ison to the epoxy, which could have been obtained using a traditional analysis approach

  12. Conductor and joint test results of JT-60SA CS and EF coils using the NIFS test facility

    NASA Astrophysics Data System (ADS)

    Obana, Tetsuhiro; Takahata, Kazuya; Hamaguchi, Shinji; Kizu, Kaname; Murakami, Haruyuki; Chikaraishi, Hirotaka; Noguchi, Hiroki; Kobuchi, Takashi; Moriuchi, Sadatomo; Imagawa, Shinsaku; Mito, Toshiyuki; Tsuchiya, Katsuhiko; Natsume, Kyohei; Yoshida, Kiyoshi; Nomoto, Kazuhiro; Kim, Tae-hyun

    2016-01-01

    In 2007, JAEA and NIFS launched the test project to evaluate the performance of cable-in-conduit (CIC) conductors and conductor joints for the JT-60SA CS and EF coils. In this project, conductor tests for four types of coil conductor and joint tests for seven types of conductor joint have been conducted for the past eight years using the NIFS test facility. As a result, the test project indicated that the CIC conductors and conductor joints fulfill the design requirement for the CS and EF coils. In addition, the NIFS test facility is expected to be utilized as the test facility for the development of a conductor and conductor joint for the purpose of the DEMO nuclear fusion power plant, provided that the required magnetic field strength is within 9 T.

  13. Robust joint score tests in the application of DNA methylation data analysis.

    PubMed

    Li, Xuan; Fu, Yuejiao; Wang, Xiaogang; Qiu, Weiliang

    2018-05-18

    Recently differential variability has been showed to be valuable in evaluating the association of DNA methylation to the risks of complex human diseases. The statistical tests based on both differential methylation level and differential variability can be more powerful than those based only on differential methylation level. Anh and Wang (2013) proposed a joint score test (AW) to simultaneously detect for differential methylation and differential variability. However, AW's method seems to be quite conservative and has not been fully compared with existing joint tests. We proposed three improved joint score tests, namely iAW.Lev, iAW.BF, and iAW.TM, and have made extensive comparisons with the joint likelihood ratio test (jointLRT), the Kolmogorov-Smirnov (KS) test, and the AW test. Systematic simulation studies showed that: 1) the three improved tests performed better (i.e., having larger power, while keeping nominal Type I error rates) than the other three tests for data with outliers and having different variances between cases and controls; 2) for data from normal distributions, the three improved tests had slightly lower power than jointLRT and AW. The analyses of two Illumina HumanMethylation27 data sets GSE37020 and GSE20080 and one Illumina Infinium MethylationEPIC data set GSE107080 demonstrated that three improved tests had higher true validation rates than those from jointLRT, KS, and AW. The three proposed joint score tests are robust against the violation of normality assumption and presence of outlying observations in comparison with other three existing tests. Among the three proposed tests, iAW.BF seems to be the most robust and effective one for all simulated scenarios and also in real data analyses.

  14. Extended tensile testing of welded joints of polyethylene pipes

    NASA Astrophysics Data System (ADS)

    Danzanova, E. V.; Gerasimov, A. I.; Botvin, G. V.

    2017-12-01

    The paper introduces the results of testing joints welded in the open air at low climatic temperatures (below minus 15 °C) without heated facilities. Extended tensile testing in an active medium reveals that the same quality standard of welded joints is reached when welded parts are preheated when welding is performed under conditions of low climatic temperatures, and when they are welded at permissible temperatures.

  15. Results and Analysis from Space Suit Joint Torque Testing

    NASA Technical Reports Server (NTRS)

    Matty, Jennifer

    2010-01-01

    A space suit's mobility is critical to an astronaut's ability to perform work efficiently. As mobility increases, the astronaut can perform tasks for longer durations with less fatigue. Mobility can be broken down into two parts: range of motion (ROM) and torque. These two measurements describe how the suit moves and how much force it takes to move. Two methods were chosen to define mobility requirements for the Constellation Space Suit Element (CSSE). One method focuses on range of motion and the second method centers on joint torque. A joint torque test was conducted to determine a baseline for current advanced space suit joint torques. This test utilized the following space suits: Extravehicular Mobility Unit (EMU), Advanced Crew Escape Suit (ACES), I-Suit, D-Suit, Enhanced Mobility (EM)- ACES, and Mark III (MK-III). Data was collected data from 16 different joint movements of each suit. The results were then reviewed and CSSE joint torque requirement values were selected. The focus of this paper is to discuss trends observed during data analysis.

  16. 21 CFR 58.107 - Test and control article handling.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Test and control article handling. 58.107 Section... GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Test and Control Articles § 58.107 Test and control article handling. Procedures shall be established for a system for the handling of the test and...

  17. 21 CFR 58.107 - Test and control article handling.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Test and control article handling. 58.107 Section... GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Test and Control Articles § 58.107 Test and control article handling. Procedures shall be established for a system for the handling of the test and...

  18. 21 CFR 58.107 - Test and control article handling.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Test and control article handling. 58.107 Section... GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Test and Control Articles § 58.107 Test and control article handling. Procedures shall be established for a system for the handling of the test and...

  19. 21 CFR 58.107 - Test and control article handling.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Test and control article handling. 58.107 Section... GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Test and Control Articles § 58.107 Test and control article handling. Procedures shall be established for a system for the handling of the test and...

  20. Analysis and testing of a space crane articulating joint testbed

    NASA Technical Reports Server (NTRS)

    Sutter, Thomas R.; Wu, K. Chauncey

    1992-01-01

    The topics are presented in viewgraph form and include: space crane concept with mobile base; mechanical versus structural articulating joint; articulating joint test bed and reference truss; static and dynamic characterization completed for space crane reference truss configuration; improved linear actuators reduce articulating joint test bed backlash; 1-DOF space crane slew maneuver; boom 2 tip transient response finite element dynamic model; boom 2 tip transient response shear-corrected component modes torque driver profile; peak root member force vs. slew time torque driver profile; and open loop control of space crane motion.

  1. Experimental Study of the Compression Response of Fluted-Core Composite Panels with Joints

    NASA Technical Reports Server (NTRS)

    Schultz, Marc R.; Rose, Cheryl A.; Guzman, J. Carlos; McCarville, Douglas; Hilburger, Mark W.

    2012-01-01

    Fluted-core sandwich composites consist of integral angled web members spaced between laminate face sheets, and may have the potential to provide benefits over traditional sandwich composites for certain aerospace applications. However, fabrication of large autoclave-cured fluted-core cylindrical shells with existing autoclaves will require that the shells be fabricated in segments, and joined longitudinally to form a complete barrel. Two different longitudinal fluted-core joint designs were considered experimentally in this study. In particular, jointed fluted-core-composite panels were tested in longitudinal compression because longitudinal compression is the primary loading condition in dry launch-vehicle barrel sections. One of the joint designs performed well in comparison with unjointed test articles, and the other joint design failed at loads approximately 14% lower than unjointed test articles. The compression-after-impact (CAI) performance of jointed fluted-core composites was also investigated by testing test articles that had been subjected to 6 ft-lb impacts. It was found that such impacts reduced the load-carrying capability by 9% to 40%. This reduction is dependent on the joint concept, component flute size, and facesheet thickness.

  2. Orion Crew Module Structural Test Article Offload

    NASA Image and Video Library

    2016-11-15

    After arriving at the Shuttle Landing Facility operated by Space Florida at NASA's Kennedy Space Center in Florida, the agency's Super Guppy aircraft has been opened and the container holding the Orion crew module structural test article (STA) is being offloaded. The test article will be transported to the Neil Armstrong Operations and Checkout Building high bay for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  3. Orion Crew Module Structural Test Article Offload

    NASA Image and Video Library

    2016-11-15

    After arriving at the Shuttle Landing Facility operated by Space Florida at NASA's Kennedy Space Center in Florida, the agency's Super Guppy aircraft was opened and the container holding the Orion crew module structural test article (STA) was offloaded. The test article will be transported to the Neil Armstrong Operations and Checkout Building high bay for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  4. Joint Service Magazine Advertising Test. Spring 1978.

    DTIC Science & Technology

    1979-04-01

    This is a test of the relative efficiency and effectiveness of joint Service advertising versus solo Service advertising of the Active Services...Subtests conducted were performance of page versus spread advertisements and four box versus three-line business reply cards. Call back research was conducted to validate findings of the major test. (Author)

  5. 21 CFR 58.105 - Test and control article characterization.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Test and control article characterization. 58.105... GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Test and Control Articles § 58.105 Test and control article characterization. (a) The identity, strength, purity, and composition or other...

  6. 21 CFR 58.105 - Test and control article characterization.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Test and control article characterization. 58.105... GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Test and Control Articles § 58.105 Test and control article characterization. (a) The identity, strength, purity, and composition or other...

  7. 21 CFR 58.105 - Test and control article characterization.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Test and control article characterization. 58.105... GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Test and Control Articles § 58.105 Test and control article characterization. (a) The identity, strength, purity, and composition or other...

  8. 21 CFR 58.105 - Test and control article characterization.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Test and control article characterization. 58.105... GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Test and Control Articles § 58.105 Test and control article characterization. (a) The identity, strength, purity, and composition or other...

  9. 21 CFR 58.105 - Test and control article characterization.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Test and control article characterization. 58.105... GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Test and Control Articles § 58.105 Test and control article characterization. (a) The identity, strength, purity, and composition or other...

  10. Orion Crew Module Structural Test Article Offload

    NASA Image and Video Library

    2016-11-15

    NASA’s Super Guppy aircraft, carrying the Orion crew module structural test article, arrived at the Shuttle Landing Facility operated by Space Florida at NASA’s Kennedy Space Center in Florida. The unique aircraft has been opened to reveal the container holding the STA. The test article will be transported to the Neil Armstrong Operations and Checkout Building high bay for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  11. Orion Crew Module Structural Test Article Unbagging

    NASA Image and Video Library

    2016-11-15

    Inside the Neil Armstrong Operations and Checkout Building high bay at NASA's Kennedy Space Center in Florida, Lockheed Martin technicians remove the protective covering from the Orion crew module structural test article (STA). The STA arrived aboard NASA's Super Guppy aircraft at the Shuttle Landing Facility operated by Space Florida. The test article was moved inside the facility's high bay for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  12. Orion Crew Module Structural Test Article Unbagging

    NASA Image and Video Library

    2016-11-15

    Inside the Neil Armstrong Operations and Checkout Building high bay at NASA's Kennedy Space Center in Florida, the cover has been removed from the container holding the Orion crew module structural test article (STA). The STA arrived aboard NASA's Super Guppy aircraft at the Shuttle Landing Facility operated by Space Florida. The test article was moved inside the facility's high bay for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  13. Orion Crew Module Structural Test Article Offload

    NASA Image and Video Library

    2016-11-15

    NASA’s Super Guppy aircraft, carrying the Orion crew module structural test article (STA), arrived at the Shuttle Landing Facility operated by Space Florida at NASA’s Kennedy Space Center in Florida. The unique aircraft is being opened to offload the STA. The test article will be transported to the Neil Armstrong Operations and Checkout Building high bay for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  14. Orion Crew Module Structural Test Article Offload

    NASA Image and Video Library

    2016-11-15

    NASA’s Super Guppy aircraft, carrying the Orion crew module structural test article (STA), arrived at the Shuttle Landing Facility operated by Space Florida at NASA’s Kennedy Space Center in Florida. The front of the unique aircraft is being opened to offload the STA. The test article will be transported to the Neil Armstrong Operations and Checkout Building high bay for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  15. Orion Crew Module Structural Test Article Offload

    NASA Image and Video Library

    2016-11-15

    After arriving at the Shuttle Landing Facility operated by Space Florida at NASA's Kennedy Space Center in Florida, the agency's Super Guppy aircraft was opened and the container holding the Orion crew module structural test article (STA) was offloaded. A crane has lifted the container for placement on a transporter. The test article will be moved to the Neil Armstrong Operations and Checkout Building high bay for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  16. Orion Crew Module Structural Test Article Offload

    NASA Image and Video Library

    2016-11-15

    After arriving at the Shuttle Landing Facility operated by Space Florida at NASA's Kennedy Space Center in Florida, the agency's Super Guppy aircraft was opened and the container holding the Orion crew module structural test article (STA) was offloaded. A crane was used to lower the container onto a transporter. The test article will be moved to the Neil Armstrong Operations and Checkout Building high bay for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  17. Orion Crew Module Structural Test Article Unbagging

    NASA Image and Video Library

    2016-11-15

    Inside the Neil Armstrong Operations and Checkout Building high bay at NASA's Kennedy Space Center in Florida, the protective covering was removed from the Orion crew module structural test article (STA). It remains secured on the bottom of its transport container. The STA arrived aboard NASA's Super Guppy aircraft at the Shuttle Landing Facility operated by Space Florida. The test article was moved inside the facility's high bay for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  18. Orion Crew Module Structural Test Article Offload

    NASA Image and Video Library

    2016-11-15

    After arriving at the Shuttle Landing Facility operated by Space Florida at NASA's Kennedy Space Center in Florida, the agency's Super Guppy aircraft has been opened and the container holding the Orion crew module structural test article (STA) is being offloaded. The test article will be transported to the Neil Armstrong Operations and Checkout Building high bay for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018. Photo credit: NASA/Ben Smegelsky

  19. Orion Crew Module Structural Test Article Offload

    NASA Image and Video Library

    2016-11-15

    After arriving at the Shuttle Landing Facility operated by Space Florida at NASA's Kennedy Space Center in Florida, the agency's Super Guppy aircraft was opened and the container holding the Orion crew module structural test article (STA) was offloaded. A crane is used to lower the container for placement on a transporter. The test article will be moved to the Neil Armstrong Operations and Checkout Building high bay for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  20. Orion Crew Module Structural Test Article Offload

    NASA Image and Video Library

    2016-11-15

    NASA’s Super Guppy aircraft, carrying the Orion crew module structural test article, arrived at the Shuttle Landing Facility operated by Space Florida at NASA’s Kennedy Space Center in Florida. The unique aircraft has been opened and the container holding the STA is being offloaded. The test article will be transported to the Neil Armstrong Operations and Checkout Building high bay for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  1. Orion Crew Module Structural Test Article Unbagging

    NASA Image and Video Library

    2016-11-15

    Inside the Neil Armstrong Operations and Checkout Building high bay at NASA's Kennedy Space Center in Florida, technicians with Lockheed Martin look over the Orion crew module structural test article (STA) secured on the bottom of its transport container. The STA arrived aboard NASA's Super Guppy aircraft at the Shuttle Landing Facility operated by Space Florida. The test article was moved inside the facility's high bay for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  2. Joint Test and Evaluation Procedures Manual.

    DTIC Science & Technology

    1980-09-01

    offices within 0oD such as ODDTE may allot funds to individual JTFs for purchasing goods and services. 1-12 Service support to JT&E is usually drawn...on underlying assumptions about the "real world," and that a good operational scenario may conflict with the assumptions for a specific statistical...Learned Since a good Data Management Plan is critical to the success of a joint test, some situations which have occurred in previous tests are listed

  3. Design, Analysis and Testing of a PRSEUS Pressure Cube to Investigate Assembly Joints

    NASA Technical Reports Server (NTRS)

    Yovanof, Nicolette; Lovejoy, Andrew E.; Baraja, Jaime; Gould, Kevin

    2012-01-01

    Due to its potential to significantly increase fuel efficiency, the current focus of NASA's Environmentally Responsible Aviation Program is the hybrid wing body (HWB) aircraft. Due to the complex load condition that exists in HWB structure, as compared to traditional aircraft configurations, light-weight, cost-effective and manufacturable structural concepts are required to enable the HWB. The Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) concept is one such structural concept. A building block approach for technology development of the PRSEUS concept is being conducted. As part of this approach, a PRSEUS pressure cube was developed as a risk reduction test article to examine a new integral cap joint concept. This paper describes the design, analysis and testing of the PRSEUS pressure cube test article. The pressure cube was required to withstand a 2P, 18.4 psi, overpressure load requirement. The pristine pressure cube was tested to 2.2P with no catastrophic failure. After the addition of barely visible impact damage, the cube was pressure loaded to 48 psi where catastrophic failure occurred, meeting the scale-up requirement. Comparison of pretest and posttest analyses with the cube test response agree well, and indicate that current analysis methods can be used to accurately analyze PRSEUS structure for initial failure response.

  4. A3 Subscale Diffuser Test Article Design

    NASA Technical Reports Server (NTRS)

    Saunders, G. P.

    2009-01-01

    This paper gives a detailed description of the design of the A3 Subscale Diffuser Test (SDT) Article Design. The subscale diffuser is a geometrically accurate scale model of the A3 altitude rocket facility. It was designed and built to support the SDT risk mitigation project located at the E3 facility at Stennis Space Center, MS (SSC) supporting the design and construction of the A3 facility at SSC. The subscale test article is outfitted with a large array of instrumentation to support the design verification of the A3 facility. The mechanical design of the subscale diffuser and test instrumentation are described here

  5. Push-off tests and strength evaluation of joints combining shrink fitting with bonding

    NASA Astrophysics Data System (ADS)

    Yoneno, Masahiro; Sawa, Toshiyuki; Shimotakahara, Ken; Motegi, Yoichi

    1997-03-01

    Shrink fitted joints have been used in mechanical structures. Recently, joints combining shrink fitting with anaerobic adhesives bonded between the shrink fitted surfaces have been appeared in order to increase the joint strength. In this paper, push-off test was carried out on strength of joints combining shrink fitting with bonding by material testing machine. In addition, the push-off strength of shrink fitting joints without an anaerobic adhesive was also measured. In the experiments, the effects of the shrinking allowance and the outer diameter of the rings on the joint strength are examined. The interface stress distribution in bonded shrink fitted joints subjected to a push-off load is analyzed using axisymmetrical theory of elasticity as a four-body contact problem. Using the interface stress distribution, a method for estimating joint strength is proposed. The experimental results are in a fairly good agreement with the numerical results. It is found that the strength of combination joints is greater than that of shrink fitted joints.

  6. INTERIM CRYOGENIC PROPULSION STAGE TEST ARTICLE UNLOADED PRIOR T

    NASA Image and Video Library

    2016-06-20

    TWO CRANES LIFT THE APPROXIMATELY 8,000-POUND INTERIM CRYOGENIC PROPULSION STAGE TEST ARTICLE OUT OF ITS CRATE AT MARSHALL. THE TEST ARTICLE ARRIVED AT MARSHALL SPACE FLIGHT CENTER VIA BARGE ON THE TENNESSEE RIVER AND WAS TRANSPORTED TO BUILDING 4649 WHERE TESTING WILL BEGIN.

  7. Description of and preliminary tests results for the Joint Damping Experiment (JDX)

    NASA Technical Reports Server (NTRS)

    Bingham, Jeffrey G.; Folkman, Steven L.

    1995-01-01

    An effort is currently underway to develop an experiment titled joint Damping E_periment (JDX) to fly on the Space Shuttle as Get Away Special Payload G-726. This project is funded by NASA's IN-Space Technology Experiments Program and is scheduled to fly in July 1995 on STS-69. JDX will measure the influence of gravity on the structural damping of a three bay truss having clearance fit pinned joints. Structural damping is an important parameter in the dynamics of space structures. Future space structures will require more precise knowledge of structural damping than is currently available. The mission objectives are to develop a small-scale shuttle flight experiment that allows researchers to: (1) characterize the influence of gravity and joint gaps on structural damping and dynamic behavior of a small-scale truss model, and (2) evaluate the applicability of low-g aircraft test results for predicting on-orbit behavior. Completing the above objectives will allow a better understanding and/or prediction of structural damping occurring in a pin jointed truss. Predicting damping in joints is quite difficult. One of the important variables influencing joint damping is gravity. Previous work has shown that gravity loads can influence damping in a pin jointed truss structure. Flying this experiment as a GAS payload will allow testing in a microgravity environment. The on-orbit data (in micro-gravity) will be compared with ground test results. These data will be used to help develop improved models to predict damping due to pinned joints. Ground and low-g aircraft testing of this experiment has been completed. This paper describes the experiment and presents results of both ground and low-g aircraft tests which demonstrate that damping of the truss is dramatically influenced by gravity.

  8. Design, fabrication and test of graphite/polymide composite joints and attachments: Summary

    NASA Technical Reports Server (NTRS)

    Cushman, J. B.; Mccleskey, S. F.; Ward, S. H.

    1983-01-01

    The design, analysis and testing performed to develop four types of graphite/polyimide (Gr/PI) bonded and bolted composite joints for lightly loaded control surfaces on advanced space transportation systems that operate at temperatures up to 561K (550 F) are summarized. Material properties and 'small specimen' tests were conducted to establish design data and to evaluate specific design details. 'Static discriminator' tests were conducted on preliminary designs to verify structural adequacy. Scaled up specimens of the final joint designs, representative of production size requirements, were subjected to a series of static and fatigue tests to evaluate joint strength. Effects of environmental conditioning were determined by testing aged (125 hours 589K (600 F)) and thermal cycled (116K to 589K (-250 F to 600 F), 125 times) specimens. It is concluded Gr/PI joints can be designed and fabricated to carry the specified loads. Test results also indicate a possible resin loss or degradation of laminates after exposure to 589K (600 F) for 125 hours.

  9. Working on a Standard Joint Unit: A pilot test.

    PubMed

    Casajuana, Cristina; López-Pelayo, Hugo; Mercedes Balcells, María; Miquel, Laia; Teixidó, Lídia; Colom, Joan; Gual, Antoni

    2017-09-29

    Assessing cannabis consumption remains complex due to no reliable registration systems. We tested the likelihood of establishing a Standard Joint Unit (SJU) which considers the main cannabinoids with implication on health through a naturalistic approach.  Methodology. Pilot study with current cannabis users of four areas of Barcelona: universities, nightclubs, out-patient mental health service, and cannabis associations. We designed and administered a questionnaire on cannabis use-patterns and determined the willingness to donate a joint for analysis. Descriptive statistics were used to analyze the data. Forty volunteers answered the questionnaire (response rate 95%); most of them were men (72.5%) and young adults (median age 24.5 years; IQR 8.75 years) who consume daily or nearly daily (70%). Most participants consume marihuana (85%) and roll their joints with a median of 0.25 gr of marihuana. Two out of three (67.5%) stated they were willing to donate a joint. Obtaining an SJU with the planned methodology has proved to be feasible. Pre-testing resulted in an improvement of the questionnaire and retribution to incentivize donations. Establishing an SJU is essential to improve our knowledge on cannabis-related outcomes.

  10. Joint ETV/NOWATECH test plan for the Sorbisense GSW40 passive sampler

    EPA Science Inventory

    The joint test plan is the implementation of a test design developed for verification of the performance of an environmental technology following the NOWATECH ETV method. The verification is a joint verification with the US EPA ETV scheme and the Advanced Monitoring Systems Cent...

  11. Joint Test Director. Joint Logistics Over-the-Shore II. Test and Evaluation. Analysis and Evaluation Report. JLOTS II Throughput Test.

    DTIC Science & Technology

    1985-08-01

    Class high - speed containerships and their subsequent conversion to a cargo configuration specifically designed for rapid load-offload of military unit...Rough Terrain Forklift SLWT Side-Loadable Warping Tug ST Short Ton STON Short Ton SUROB Surf Observations T-ACS Auxiliary Crane Ship T- AKR Auxiliary Cargo ...their delivery systems for container, breakbulk, and bulk liquid cargo , and to define the operating performance of the combined systems in a joint test

  12. Methods for the Joint Meta-Analysis of Multiple Tests

    ERIC Educational Resources Information Center

    Trikalinos, Thomas A.; Hoaglin, David C.; Small, Kevin M.; Terrin, Norma; Schmid, Christopher H.

    2014-01-01

    Existing methods for meta-analysis of diagnostic test accuracy focus primarily on a single index test. We propose models for the joint meta-analysis of studies comparing multiple index tests on the same participants in paired designs. These models respect the grouping of data by studies, account for the within-study correlation between the tests'…

  13. Orion Crew Module Structural Test Article Lift & Uncrating

    NASA Image and Video Library

    2016-11-15

    Inside the Neil Armstrong Operations and Checkout Building high bay at NASA's Kennedy Space Center in Florida, the cover has been removed from the container holding the Orion crew module structural test article (STA). The STA arrived aboard NASA's Super Guppy aircraft at the Shuttle Landing Facility operated by Space Florida. The test article was moved inside the facility's high bay for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  14. New Technique for Cryogenically Cooling Small Test Articles

    NASA Technical Reports Server (NTRS)

    Rodriquez, Karen M.; Henderson, Donald J.

    2011-01-01

    Convective heat removal techniques to rapidly cool small test articles to Earth-Moon L2 temperatures of 77 K were accomplished through the use of liquid nitrogen (LN2). By maintaining a selected pressure range on the saturation curve, test articles were cooled below the LN2 boiling point at ambient pressure in less than 30 min. Difficulties in achieving test pressures while maintaining the temperature tolerance necessitated a modification to the original system to include a closed loop conductive cold plate and cryogenic shroud

  15. Ability of finger-jointed lumber to maintain load at elevated temperatures

    Treesearch

    Douglas R. Rammer; Samuel L. Zelinka; Laura E Hasburgh; Steven T. Craft

    2018-01-01

    This article presents a test method that was developed to screen adhesive formulations for finger-jointed lumber. The goal was to develop a small-scale test that could be used to predict whether an adhesive would pass a full-scale ASTM E119 wall assembly test. The method involved loading a 38-mm square finger-jointed sample in a four-point bending test inside of an...

  16. Prototype space erectable radiator system ground test article development

    NASA Technical Reports Server (NTRS)

    Alario, Joseph P.

    1988-01-01

    A prototype heat rejecting system is being developed by NASA-JSC for possible space station applications. This modular system, the Space-Erectable Radiator System Ground Test Article (SERS-GTA) with high-capacity radiator panels, can be installed and replaced on-orbit. The design, fabrication and testing of a representative ground test article are discussed. Acceptance test data for the heat pipe radiator panel and the whiffletree clamping mechanism have been presented.

  17. Orion Crew Module Structural Test Article Lift & Uncrating

    NASA Image and Video Library

    2016-11-15

    Inside the Neil Armstrong Operations and Checkout Building high bay at NASA's Kennedy Space Center in Florida, technicians with Lockheed Martin assist as a crane lifts the cover away from the container holding the Orion crew module structural test article (STA). The STA arrived aboard NASA's Super Guppy aircraft at the Shuttle Landing Facility operated by Space Florida. The test article was moved inside the facility's high bay for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  18. Orion Crew Module Structural Test Article Lift & Uncrating

    NASA Image and Video Library

    2016-11-15

    Inside the Neil Armstrong Operations and Checkout Building high bay at NASA's Kennedy Space Center in Florida, a crane lifts the cover up from the container holding the Orion crew module structural test article (STA). The STA arrived aboard NASA's Super Guppy aircraft at the Shuttle Landing Facility operated by Space Florida. The test article was moved inside the facility's high bay for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  19. Cadre Photos for Joint Test Team Feature

    NASA Image and Video Library

    2017-02-23

    During a tour of SpaceX headquarters in Hawthorne, California, commercial crew astronauts Bob Behnken, left, and Eric Boe participate in joint test team training using mockup components of the Crew Dragon on Feb. 23, 2017. Mike Good, program manager for Crew Operations and Testing at Johnson Space Center in Houston, is in the background. Crew Dragon is being developed and manufactured in partnership with NASA's Commercial Crew Program to return human spaceflight capabilities to the U.S.

  20. Accelerated Comparative Fatigue Strength Testing of Belt Adhesive Joints

    NASA Astrophysics Data System (ADS)

    Bajda, Miroslaw; Blazej, Ryszard; Jurdziak, Leszek

    2017-12-01

    Belt joints are the weakest link in the serial structure that creates an endless loop of spliced belt segments. This affects not only the lower strength of adhesive joints of textile belts in comparison to vulcanized splices, but also the replacement of traditional glues to more ecological but with other strength parameters. This is reflected in the lowered durability of adhesive joints, which in underground coal mines is nearly twice shorter than the operating time of belts. Vulcanized splices require high precision in performance, they need long time to achieve cross-linking of the friction mixture and, above all, they require specialized equipment (vulcanization press) which is not readily available and often takes much time to be delivered down, which means reduced mining output or even downtime. All this reduces the reliability and durability of adhesive joints. In addition, due to the consolidation on the Polish coal market, mines are joined into large economic units serviced by a smaller number of processing plants. The consequence is to extend the transport routes downstream and increase reliability requirements. The greater number of conveyors in the chain reduces reliability of supply and increases production losses. With high fixed costs of underground mines, the reduction in mining output is reflected in the increase in unit costs, and this at low coal prices on the market can mean substantial losses for mines. The paper describes the comparative study of fatigue strength of shortened samples of adhesive joints conducted to compare many different variants of joints (various adhesives and materials). Shortened samples were exposed to accelerated fatigue in the usually long-lasting dynamic studies, allowing more variants to be tested at the same time. High correlation between the results obtained for shortened (100 mm) and traditional full-length (3×250 mm) samples renders accelerated tests possible.

  1. Tension and Bending Testing of an Integral T-Cap for Stitched Composite Airframe Joints

    NASA Technical Reports Server (NTRS)

    Lovejoy, Andrew E.; Leone, Frank A., Jr.

    2016-01-01

    The Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) is a structural concept that was developed by The Boeing Company to address the complex structural design aspects associated with a pressurized hybrid wing body aircraft configuration. An important design feature required for assembly is the integrally stitched T-cap, which provides connectivity of the corner (orthogonal) joint between adjacent panels. A series of tests were conducted on T-cap test articles, with and without a rod stiffener penetrating the T-cap web, under tension (pull-off) and bending loads. Three designs were tested, including the baseline design used in large-scale test articles. The baseline had only the manufacturing stitch row adjacent to the fillet at the base of the T-cap web. Two new designs added stitching rows to the T-cap web at either 0.5- or 1.0-inch spacing along the height of the web. Testing was conducted at NASA Langley Research Center to determine the behavior of the T-cap region resulting from the applied loading. Results show that stitching arrests the initial delamination failures so that the maximum strength capability exceeds the load at which the initial delaminations develop. However, it was seen that the added web stitching had very little effect on the initial delamination failure load, but actually decreased the initial delamination failure load for tension loading of test articles without a stiffener passing through the web. Additionally, the added web stitching only increased the maximum load capability by between 1% and 12.5%. The presence of the stiffener, however, did increase the initial and maximum loads for both tension and bending loading as compared to the stringerless baseline design. Based on the results of the few samples tested, the additional stitching in the T-cap web showed little advantage over the baseline design in terms of structural failure at the T-cap web/skin junction for the current test articles.

  2. US/Russian Joint Film Test

    NASA Technical Reports Server (NTRS)

    Slater, Richard

    1996-01-01

    A joint U.S./Russian film test was conducted during MIR Mission 18 to evaluate the effects of radiation on photographic film during long-duration space flights. Two duplicate sets of film were flown on this MIR mission: one set was processed and evaluated by the NASA/JSC Photographic Laboratory, and the other by the RKK Energia's Photographic Laboratory in Moscow. This preliminary report includes only the results of the JSC evaluation (excluding the SN-10 film which was not available for evaluation at the time this report was written). The final report will include an evaluation by JSC of the SN-10 film and an evaluation of the test data by the RKK Energia. ISC's evaluation of the test data showed the positive film flown was damaged very little when exposed to approximately 8 rads of radiation. Two of the three negative films were significantly damaged and the third film was damaged only moderately.

  3. US/Russian Joint Film Test

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Slater, R.

    1996-04-01

    A joint U.S./Russian film test was conducted during MIR Mission 18 to evaluate the effects of radiation on photographic film during long-duration space flights. Two duplicate sets of film were flown on this MIR mission: one set was processed and evaluated by the NASA/JSC Photographic Laboratory, and the other by the RKK Energia`s Photographic Laboratory in Moscow. This preliminary report includes only the results of the JSC evaluation (excluding the SN-10 film which was not available for evaluation at the time this report was written). The final report will include an evaluation by JSC of the SN-10 film and anmore » evaluation of the test data by the RKK Energia. ISC`s evaluation of the test data showed the positive film flown was damaged very little when exposed to approximately 8 rads of radiation. Two of the three negative films were significantly damaged and the third film was damaged only moderately.« less

  4. 48 CFR 52.209-3 - First Article Approval-Contractor Testing.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 2 2011-10-01 2011-10-01 false First Article Approval... Clauses 52.209-3 First Article Approval—Contractor Testing. As prescribed in 9.308-1 (a) and (b), insert the following clause: First Article Approval—Contractor Testing (SEP 1989) [Contracting Officer shall...

  5. 48 CFR 52.209-4 - First Article Approval-Government Testing.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 2 2013-10-01 2013-10-01 false First Article Approval... Clauses 52.209-4 First Article Approval—Government Testing. As prescribed in 9.308-2 (a) and (b), insert the following clause: First Article Approval—Government Testing (SEP 1989) [Contracting Officer shall...

  6. 48 CFR 52.209-4 - First Article Approval-Government Testing.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 2 2012-10-01 2012-10-01 false First Article Approval... Clauses 52.209-4 First Article Approval—Government Testing. As prescribed in 9.308-2 (a) and (b), insert the following clause: First Article Approval—Government Testing (SEP 1989) [Contracting Officer shall...

  7. 48 CFR 52.209-4 - First Article Approval-Government Testing.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false First Article Approval... Clauses 52.209-4 First Article Approval—Government Testing. As prescribed in 9.308-2 (a) and (b), insert the following clause: First Article Approval—Government Testing (SEP 1989) [Contracting Officer shall...

  8. 48 CFR 52.209-4 - First Article Approval-Government Testing.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 2 2014-10-01 2014-10-01 false First Article Approval... Clauses 52.209-4 First Article Approval—Government Testing. As prescribed in 9.308-2 (a) and (b), insert the following clause: First Article Approval—Government Testing (SEP 1989) [Contracting Officer shall...

  9. 48 CFR 52.209-3 - First Article Approval-Contractor Testing.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 2 2014-10-01 2014-10-01 false First Article Approval... Clauses 52.209-3 First Article Approval—Contractor Testing. As prescribed in 9.308-1 (a) and (b), insert the following clause: First Article Approval—Contractor Testing (SEP 1989) [Contracting Officer shall...

  10. 48 CFR 52.209-3 - First Article Approval-Contractor Testing.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 2 2012-10-01 2012-10-01 false First Article Approval... Clauses 52.209-3 First Article Approval—Contractor Testing. As prescribed in 9.308-1 (a) and (b), insert the following clause: First Article Approval—Contractor Testing (SEP 1989) [Contracting Officer shall...

  11. 48 CFR 52.209-4 - First Article Approval-Government Testing.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 2 2011-10-01 2011-10-01 false First Article Approval... Clauses 52.209-4 First Article Approval—Government Testing. As prescribed in 9.308-2 (a) and (b), insert the following clause: First Article Approval—Government Testing (SEP 1989) [Contracting Officer shall...

  12. 48 CFR 52.209-3 - First Article Approval-Contractor Testing.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 2 2013-10-01 2013-10-01 false First Article Approval... Clauses 52.209-3 First Article Approval—Contractor Testing. As prescribed in 9.308-1 (a) and (b), insert the following clause: First Article Approval—Contractor Testing (SEP 1989) [Contracting Officer shall...

  13. 48 CFR 52.209-3 - First Article Approval-Contractor Testing.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false First Article Approval... Clauses 52.209-3 First Article Approval—Contractor Testing. As prescribed in 9.308-1 (a) and (b), insert the following clause: First Article Approval—Contractor Testing (SEP 1989) [Contracting Officer shall...

  14. Cadre Photos for Joint Test Team Feature

    NASA Image and Video Library

    2017-02-23

    During a tour of SpaceX headquarters in Hawthorne, California, commercial crew astronauts Suni Williams, left, and Doug Hurley participate in joint test team training using mockup components of the Crew Dragon on Feb. 23, 2017. Crew Dragon is being developed and manufactured in partnership with NASA's Commercial Crew Program to return human spaceflight capabilities to the U.S.

  15. Cadre Photos for Joint Test Team Feature

    NASA Image and Video Library

    2017-02-23

    During a tour of SpaceX headquarters in Hawthorne, California, commercial crew astronauts Bob Behnken, left, and Eric Boe participate in joint test team training using mockup components of the Crew Dragon on Feb. 23, 2017. Crew Dragon is being developed and manufactured in partnership with NASA's Commercial Crew Program to return human spaceflight capabilities to the U.S.

  16. Long memory and multifractality: A joint test

    NASA Astrophysics Data System (ADS)

    Goddard, John; Onali, Enrico

    2016-06-01

    The properties of statistical tests for hypotheses concerning the parameters of the multifractal model of asset returns (MMAR) are investigated, using Monte Carlo techniques. We show that, in the presence of multifractality, conventional tests of long memory tend to over-reject the null hypothesis of no long memory. Our test addresses this issue by jointly estimating long memory and multifractality. The estimation and test procedures are applied to exchange rate data for 12 currencies. Among the nested model specifications that are investigated, in 11 out of 12 cases, daily returns are most appropriately characterized by a variant of the MMAR that applies a multifractal time-deformation process to NIID returns. There is no evidence of long memory.

  17. The development and testing of the Lens Antenna Deployment Demonstration (LADD) test article

    NASA Technical Reports Server (NTRS)

    Pugh, Mark L.; Denton, Robert J., Jr.; Strange, Timothy J.

    1993-01-01

    The USAF Rome Laboratory and NASA Marshall Space Flight Center, through contract to Grumman Corporation, have developed a space-qualifiable test article for the Strategic Defense Initiative Organization to demonstrate the critical structural and mechanical elements of single-axis roll-out membrane deployment for Space Based Radar (SBR) applications. The Lens Antenna Deployment Demonstration (LADD) test article, originally designed as a shuttle-attached flight experiment, is a large precision space structure which is representative of operational designs for space-fed lens antennas. Although the flight experiment was cancelled due to funding constraints and major revisions in the Strategic Defense System (SDS) architecture, development of this test article was completed in June 1989. To take full advantage of the existence of this unique structure, a series of ground tests are proposed which include static, dynamic, and thermal measurements in a simulated space environment. An equally important objective of these tests is the verification of the analytical tools used to design and develop large precision space structures.

  18. Orion Crew Module Structural Test Article Arrival

    NASA Image and Video Library

    2016-11-14

    NASA’s Super Guppy aircraft touches down at the Shuttle Landing Facility at the agency’s Kennedy Space Center in Florida, carrying the Orion crew module structural test article (STA). The STA will be offloaded and transported to the Neil Armstrong Operations and Checkout Building high bay for further testing. Photo credit: NASA/Kim Shiflett

  19. Test and analysis of Celion 3000/PMR-15, graphite/polyimide bonded composite joints: Data report

    NASA Technical Reports Server (NTRS)

    Cushman, J. B.; Mccleskey, S. F.; Ward, S. H.

    1982-01-01

    Standard single lap, double lap and symmetric step lap bonded joints of Celion 3000/PMR-15 graphite/polyimide composite were evaluated. Composite to composite and composite to titanium joints were tested at 116 K (-250 F), 294 K (70 F) and 561 K (550 F). Joint parameters evaluated are lap length, adherend thickness, adherend axial stiffness, lamina stacking sequence and adherend tapering. Advanced joint concepts were examined to establish the change in performance of preformed adherends, scalloped adherends and hybrid systems. The material properties of the high temperature adhesive, designated A7F, used for bonding were established. The bonded joint tests resulted in interlaminar shear or peel failures of the composite and there were very few adhesive failures. Average test results agree with expected performance trends for the various test parameters. Results of finite element analyses and of test/analysis correlations are also presented.

  20. Integrated Cryogenic Propulsion Test Article Thermal Vacuum Hotfire Testing

    NASA Technical Reports Server (NTRS)

    Morehead, Robert L.; Melcher, J. C.; Atwell, Matthew J.; Hurlbert, Eric A.

    2017-01-01

    In support of a facility characterization test, the Integrated Cryogenic Propulsion Test Article (ICPTA) was hotfire tested at a variety of simulated altitude and thermal conditions in the NASA Glenn Research Center Plum Brook Station In-Space Propulsion Thermal Vacuum Chamber (formerly B2). The ICPTA utilizes liquid oxygen and liquid methane propellants for its main engine and four reaction control engines, and uses a cold helium system for tank pressurization. The hotfire test series included high altitude, high vacuum, ambient temperature, and deep cryogenic environments, and several hundred sensors on the vehicle collected a range of system level data useful to characterize the operation of an integrated LOX/Methane spacecraft in the space environment - a unique data set for this propellant combination.

  1. Fabrication and Testing of Durable Redundant and Fluted-Core Joints for Composite Sandwich Structures

    NASA Technical Reports Server (NTRS)

    Lin, Shih-Yung; Splinter, Scott C.; Tarkenton, Chris; Paddock, David A.; Smeltzer, Stanley S.; Ghose, Sayata; Guzman, Juan C.; Stukus, Donald J.; McCarville, Douglas A.

    2013-01-01

    The development of durable bonded joint technology for assembling composite structures is an essential component of future space technologies. While NASA is working toward providing an entirely new capability for human space exploration beyond low Earth orbit, the objective of this project is to design, fabricate, analyze, and test a NASA patented durable redundant joint (DRJ) and a NASA/Boeing co-designed fluted-core joint (FCJ). The potential applications include a wide range of sandwich structures for NASA's future launch vehicles. Three types of joints were studied -- splice joint (SJ, as baseline), DRJ, and FCJ. Tests included tension, after-impact tension, and compression. Teflon strips were used at the joint area to increase failure strength by shifting stress concentration to a less sensitive area. Test results were compared to those of pristine coupons fabricated utilizing the same methods. Tensile test results indicated that the DRJ design was stiffer, stronger, and more impact resistant than other designs. The drawbacks of the DRJ design were extra mass and complex fabrication processes. The FCJ was lighter than the DRJ but less impact resistant. With barely visible but detectable impact damages, all three joints showed no sign of tensile strength reduction. No compression test was conducted on any impact-damaged sample due to limited scope and resource. Failure modes and damage propagation were also studied to support progressive damage modeling of the SJ and the DRJ.

  2. Selection of test paths for solder joint intermittent connection faults under DC stimulus

    NASA Astrophysics Data System (ADS)

    Huakang, Li; Kehong, Lv; Jing, Qiu; Guanjun, Liu; Bailiang, Chen

    2018-06-01

    The test path of solder joint intermittent connection faults under direct-current stimulus is examined in this paper. According to the physical structure of the circuit, a network model is established first. A network node is utilised to represent the test node. The path edge refers to the number of intermittent connection faults in the path. Then, the selection criteria of the test path based on the node degree index are proposed and the solder joint intermittent connection faults are covered using fewer test paths. Finally, three circuits are selected to verify the method. To test if the intermittent fault is covered by the test paths, the intermittent fault is simulated by a switch. The results show that the proposed method can detect the solder joint intermittent connection fault using fewer test paths. Additionally, the number of detection steps is greatly reduced without compromising fault coverage.

  3. 21 CFR 58.47 - Facilities for handling test and control articles.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Facilities for handling test and control articles... for handling test and control articles. (a) As necessary to prevent contamination or mixups, there shall be separate areas for: (1) Receipt and storage of the test and control articles. (2) Mixing of the...

  4. 21 CFR 58.47 - Facilities for handling test and control articles.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Facilities for handling test and control articles... for handling test and control articles. (a) As necessary to prevent contamination or mixups, there shall be separate areas for: (1) Receipt and storage of the test and control articles. (2) Mixing of the...

  5. 21 CFR 58.47 - Facilities for handling test and control articles.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Facilities for handling test and control articles... for handling test and control articles. (a) As necessary to prevent contamination or mixups, there shall be separate areas for: (1) Receipt and storage of the test and control articles. (2) Mixing of the...

  6. 21 CFR 58.47 - Facilities for handling test and control articles.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Facilities for handling test and control articles... for handling test and control articles. (a) As necessary to prevent contamination or mixups, there shall be separate areas for: (1) Receipt and storage of the test and control articles. (2) Mixing of the...

  7. Evaluation of effects of different treatments for the wrist joints of subdominant hands using joint proprioception and writing time.

    PubMed

    Hu, Chunying; Huang, Qiuchen; Yu, Lili; Hu, Yue; Rongming, Xia; Li, Zhou; Xiaojiao, Fu; Gu, Rui; Cui, Yao; Ge, Meng; Xu, Yanfeng; Liu, Jianfeng

    2016-05-01

    [Purpose] The purpose of this study was to examine immediate effects of strength training and NJF distal resistance training in wrist joints by using writing time and evaluation of proprioception using the JPE test. [Subjects and Methods] The subjects were 12 young healthy people (24.2 ± 3.1 y, 169.7 ± 6.5 cm, 65.3 ± 12.6 kg). Two isotonic contraction techniques were applied on the wrist joint: wrist joint extension muscle strength training (MST) and the wrist joint extension pattern of NJF. The uppercase English alphabet writing time and joint position errors of the left upper limb were measured before and after one intervention session of MST and NJF. [Results] The decrease in errors in wrist extension angle repetition and the writing time represented the improvement resulting from NJF. [Conclusion] This result suggests that the subdominant hands wrist joint proprioception and writing function can be improved by NJF together with proximal resistance training.

  8. Critical Joints in Large Composite Primary Aircraft Structures. Volume 3: Ancillary Test Results

    NASA Technical Reports Server (NTRS)

    Bunin, Bruce L.; Sagui, R. L.

    1985-01-01

    A program was conducted to develop the technology for critical structural joints for composite wing structure that meets all the design requirements of a 1990 commercial transport aircraft. The results of a comprehensive ancillary test program are summarized, consisting of single-bolt composite joint specimens tested in a variety of configurations. These tests were conducted to characterize the strength and load deflection properties that are required for multirow joint analysis. The composite material was Toray 300 fiber and Ciba-Geigy 914 resin, in the form of 0.005 and 0.01 inch thick unidirectional tape. Tests were conducted in single and double shear for loaded and unloaded hole configurations under both tensile and compressive loading. Two different layup patterns were examined. All tests were conducted at room temperature. In addition, the results of NASA Standard Toughness Test (NASA RP 1092) are reported, which were conducted for several material systems.

  9. MP Joint Arthritis

    MedlinePlus

    ... is extensive and severe, joint replacement or joint fusion are effective surgical options. Learn more about joint ... the tabs at the top (Video, Articles/WEB, Images, JHS, Products/Vendors), or the filters on the ...

  10. Orion Crew Module Structural Test Article Arrival

    NASA Image and Video Library

    2016-11-14

    NASA’s Super Guppy aircraft arrives on the tarmac after touching down at the Shuttle Landing Facility at the agency’s Kennedy Space Center in Florida. The guppy is carrying the Orion crew module structural test article (STA). The STA will be offloaded and transported to the Neil Armstrong Operations and Checkout Building high bay for further testing. Photo credit: NASA/Kim Shiflett

  11. Mechanical testing and development of the helical field coil joint for the Advanced Toroidal Facility

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nelson, B.E.; Bryan, W.E.; Goranson, P.L.

    1985-01-01

    The helical field (HF) coil set for the Advanced Toroidal Facility (ATF) is an M = 12, l = 2, constant-ratio torsatron winding consisting of 2 coils, each with 14 turns of heavy copper conductor. The coils are divided into 24 identical segments to facilitate fabrication and minimize the assembly schedule. The segments are connected across through-bolted lap joints that must carry up to 124,000 A per turn for 5 s or 62,500 A steady-state. In addition, the joints must carry the high magnetic and thermal loads induced in the conductor and still fit within the basic 140- by 30-mmmore » copper envelope. Extensive testing and development were undertaken to verify and refine the basic joint design. Tests included assembly force and clamping force for various types of misalignment; joint resistance as a function of clamping force; clamp bolt relaxation due to thermal cycling; fatigue testing of full-size, multiturn joint prototypes; and low-cycle fatigue and tensile tests of annealed CDA102 copper. The required performance parameters and actual test results, as well as the final joint configuration, are presented. 2 refs., 9 figs., 4 tabs.« less

  12. Design, fabrication and test of graphite/polyimide composite joints and attachments for advanced aerospace vehicles

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The development of several types of graphite/polyimide (GR/PI) bonded and bolted joints is reported. The program consists of two concurrent tasks: (1) design and test of specific built up attachments; and (2) evaluation of standard advanced bonded joint concepts. A data base for the design and analysis of advanced composite joints for use at elevated temperatures (561K (550 deg F)) to design concepts for specific joining applications, and the fundamental parameters controlling the static strength characteristics of such joints are evaluated. Data for design and build GR/PI of lightly loaded flight components for advanced space transportation systems and high speed aircraft are presented. Results for compression and interlaminar shear strengths of Celion 6000/PMR-15 laminates are given. Static discriminator test results for type 3 and type 4 bonded and bolted joints and final joint designs for TASK 1.4 scale up fabrication and testing are presented.

  13. Design, fabrication and test of graphite/polyimide composite joints and attachments. [spacecraft control surfaces

    NASA Technical Reports Server (NTRS)

    Cushman, J. B.; Mccleskey, S. F.; Ward, S. H.

    1982-01-01

    The design, analysis, and testing performed to develop four types of graphite/polyimide (Gr/PI) bonded and bolted composite joints for lightly loaded control surfaces on advanced space transportation systems that operate at temperatures up to 561 K (550 F) are summarized. Material properties and small specimen tests were conducted to establish design data and to evaluate specific design details. Static discriminator tests were conducted on preliminary designs to verify structural adequacy. Scaled up specimens of the final joint designs, representative of production size requirements, were subjected to a series of static and fatigue tests to evaluate joint strength. Effects of environmental conditioning were determined by testing aged (125 hours at 589 K (600 F)) and thermal cycled (116 K to 589 K (-250 F to 600 F), 125 times) specimens. It is concluded Gr/PI joints can be designed and fabricated to carry the specified loads. Test results also indicate a possible resin loss or degradation of laminates after exposure to 589 K (600 F) for 125 hours.

  14. Article and method of forming an article

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lacy, Benjamin Paul; Kottilingam, Srikanth Chandrudu; Dutta, Sandip

    Provided are an article and a method of forming an article. The method includes providing a metallic powder, heating the metallic powder to a temperature sufficient to joint at least a portion of the metallic powder to form an initial layer, sequentially forming additional layers in a build direction by providing a distributed layer of the metallic powder over the initial layer and heating the distributed layer of the metallic powder, repeating the steps of sequentially forming the additional layers in the build direction to form a portion of the article having a hollow space formed in the build direction,more » and forming an overhang feature extending into the hollow space. The article includes an article formed by the method described herein.« less

  15. Results and Analysis from Space Suit Joint Torque Testing

    NASA Technical Reports Server (NTRS)

    Matty, Jennifer E.; Aitchison, Lindsay

    2009-01-01

    A space suit s mobility is critical to an astronaut s ability to perform work efficiently. As mobility increases, the astronaut can perform tasks for longer durations with less fatigue. The term mobility, with respect to space suits, is defined in terms of two key components: joint range of motion and joint torque. Individually these measures describe the path which in which a joint travels and the force required to move it through that path. Previous space suits mobility requirements were defined as the collective result of these two measures and verified by the completion of discrete functional tasks. While a valid way to impose mobility requirements, such a method does necessitate a solid understanding of the operational scenarios in which the final suit will be performing. Because the Constellation space suit system requirements are being finalized with a relatively immature concept of operations, the Space Suit Element team elected to define mobility in terms of its constituent parts to increase the likelihood that the future pressure garment will be mobile enough to enable a broad scope of undefined exploration activities. The range of motion requirements were defined by measuring the ranges of motion test subjects achieved while performing a series of joint maximizing tasks in a variety of flight and prototype space suits. The definition of joint torque requirements has proved more elusive. NASA evaluated several different approaches to the problem before deciding to generate requirements based on unmanned joint torque evaluations of six different space suit configurations being articulated through 16 separate joint movements. This paper discusses the experiment design, data analysis and results, and the process used to determine the final values for the Constellation pressure garment joint torque requirements.

  16. Design, fabrication and test of graphite/polyimide composite joints and attachments for advanced aerospace vehicles

    NASA Technical Reports Server (NTRS)

    Barclay, D. L.

    1980-01-01

    Results of an experimental program to develop several types of graphite/polyimide (GR/PI) bonded and bolted joints for lightly loaded flight components for advanced space transportation systems and high speed aircraft are presented. Tasks accomplished include: a literature survey; design of static discriminator specimens; design allowables testing; fabrication of test panels and specimens; small specimen testing; and standard joint testing. Detail designs of static discriminator specimens for each of the four major attachment types are presented. Test results are given for the following: (1) transverse tension of Celion 3000/PMR-15 laminate; (2) net tension of a laminate for both a loaded and unloaded bolt hole; (3) comparative testing of bonded and co-cured doublers along with pull-off tests of single and double bonded angles; (4) single lap shear tests, transverse tension and coefficient of thermal expansion tests of A7F (LARC-13 amide-imide modified) adhesive; and (5) tension tests of standard single lap, double lap, and symmetric step lap bonded joints. Also, included are results of a finite element analysis of a single lap bonded composite joint.

  17. Design, fabrication and test of graphite/polyimide composite joints and attachments for advanced aerospace vehicles

    NASA Technical Reports Server (NTRS)

    Skoumal, D. E.

    1980-01-01

    Bonded and bolted designs are presented for each of four major attachment types. Prepreg processing problems are discussed and quality control data are given for lots 2W4604, 2W4632 and 2W4643. Preliminary design allowables test results for tension tests and compression tests of laminates are included. The final small specimen test matrix is defined and the configuration of symmetric step-lap joint specimens are shown. Finite element modeling studies of a double lap joint were performed to evaluate the number of elements required through the adhesive thickness to assess effects of various joint parameters on stress distributions. Results of finite element analyses assessing the effect of an adhesive fillet on the stress distribution in a double lap joint are examined.

  18. Finite Element Analysis and Test Results Comparison for the Hybrid Wing Body Center Section Test Article

    NASA Technical Reports Server (NTRS)

    Przekop, Adam; Jegley, Dawn C.; Rouse, Marshall; Lovejoy, Andrew E.

    2016-01-01

    This report documents the comparison of test measurements and predictive finite element analysis results for a hybrid wing body center section test article. The testing and analysis efforts were part of the Airframe Technology subproject within the NASA Environmentally Responsible Aviation project. Test results include full field displacement measurements obtained from digital image correlation systems and discrete strain measurements obtained using both unidirectional and rosette resistive gauges. Most significant results are presented for the critical five load cases exercised during the test. Final test to failure after inflicting severe damage to the test article is also documented. Overall, good comparison between predicted and actual behavior of the test article is found.

  19. Analysis of a Hybrid Wing Body Center Section Test Article

    NASA Technical Reports Server (NTRS)

    Wu, Hsi-Yung T.; Shaw, Peter; Przekop, Adam

    2013-01-01

    The hybrid wing body center section test article is an all-composite structure made of crown, floor, keel, bulkhead, and rib panels utilizing the Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) design concept. The primary goal of this test article is to prove that PRSEUS components are capable of carrying combined loads that are representative of a hybrid wing body pressure cabin design regime. This paper summarizes the analytical approach, analysis results, and failure predictions of the test article. A global finite element model of composite panels, metallic fittings, mechanical fasteners, and the Combined Loads Test System (COLTS) test fixture was used to conduct linear structural strength and stability analyses to validate the specimen under the most critical combination of bending and pressure loading conditions found in the hybrid wing body pressure cabin. Local detail analyses were also performed at locations with high stress concentrations, at Tee-cap noodle interfaces with surrounding laminates, and at fastener locations with high bearing/bypass loads. Failure predictions for different composite and metallic failure modes were made, and nonlinear analyses were also performed to study the structural response of the test article under combined bending and pressure loading. This large-scale specimen test will be conducted at the COLTS facility at the NASA Langley Research Center.

  20. Electromigration in solder joints and solder lines

    NASA Astrophysics Data System (ADS)

    Gan, H.; Choi, W. J.; Xu, G.; Tu, K. N.

    2002-06-01

    Electromigration may affect the reliability of flip-chip solder joints. Eutectic solder is a two-phase alloy, so its electromigration behavior is different from that in aluminum or copper interconnects. In addition, a flipchip solder joint has a built-in currentcrowding configuration to enhance electromigration failure. To better understand electromigration in SnPb and lead-free solder alloys, the authors prepared solder lines in v-grooves etched on Si (001). This article discusses the results of those tests and compares the electromigration failure modes of eutectic SnPb and SnAgCu flip-chip solder joints along with the mean-timeto-failure.

  1. SLS Engine Section Test Article Moved for Stacking at Michoud

    NASA Image and Video Library

    2017-04-25

    Stacking is underway for the Space Launch System core stage engine section structural qualification test article at NASA's Michoud Assembly Facility in New Orleans. The rocket's engine section is the bottom of the core stage and houses the four RS-25 engines. The engine section test article was moved to Michoud's Cell A in Building 110 for vertical stacking with hardware that simulates the rocket's liquid hydrogen tank, which is the fuel tank that joins to the engine section. Once stacked, the entire test article will load onto the barge Pegasus and ship to NASA's Marshall Space Flight Center in Huntsville, Alabama. There, it will be subjected to millions of pounds of force during testing to ensure the hardware can withstand the incredible stresses of launch.

  2. SLS Intertank Test Article, ITA, is attached to crosshead of loa

    NASA Image and Video Library

    2018-04-04

    SLS Intertank Test Article, ITA, is attached to crosshead of load test Annex, Bldg. 4619, and removed from bed of KMAG transporter. Rob Ziegler, (L), and Roger Myrick (R), of Aerie Aerospace attach load lines to Aft Load Ring of Intertank Test Article.

  3. Quantitative investigation of ligament strains during physical tests for sacroiliac joint pain using finite element analysis.

    PubMed

    Kim, Yoon Hyuk; Yao, Zhidong; Kim, Kyungsoo; Park, Won Man

    2014-06-01

    It may be assumed that the stability is affected when some ligaments are injured or loosened, and this joint instability causes sacroiliac joint pain. Several physical examinations have been used to diagnose sacroiliac pain and to isolate the source of the pain. However, more quantitative and objective information may be necessary to identify unstable or injured ligaments during these tests due to the lack of understanding of the quantitative relationship between the physical tests and the biomechanical parameters that may be related to pains in the sacroiliac joint and the surrounding ligaments. In this study, a three-dimensional finite element model of the sacroiliac joint was developed and the biomechanical conditions for six typical physical tests such as the compression test, distraction test, sacral apex pressure test, thigh thrust test, Patrick's test, and Gaenslen's test were modelled. The sacroiliac joint contact pressure and ligament strain were investigated for each test. The values of contact pressure and the combination of most highly strained ligaments differed markedly among the tests. Therefore, these findings in combination with the physical tests would be helpful to identify the pain source and to understand the pain mechanism. Moreover, the technology provided in this study might be a useful tool to evaluate the physical tests, to improve the present test protocols, or to develop a new physical test protocol. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Correlating PMC-MMC Bonded Joint 3D FEA with Test

    NASA Technical Reports Server (NTRS)

    Jacobson, Mindy; Rodini, Benjamin; Chen, Wayne C.; Flom, Yury A.; Posey, Alan J.

    2005-01-01

    A viewgraph presentation on the correlation of Polymer Matrix Composites (PMC) and Metal Matrix Composites (MMC) bonded joints using three dimensional finite element analyses with materials tests is shown.

  5. Orion Crew Module Structural Test Article Arrival

    NASA Image and Video Library

    2016-11-15

    NASA’s Super Guppy aircraft, carrying the Orion crew module structural test article (STA), arrives at the Shuttle Landing Facility operated by Space Florida at NASA’s Kennedy Space Center in Florida. The STA will be offloaded and transported to the Neil Armstrong Operations and Checkout Building high bay for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  6. Composite Testing

    DTIC Science & Technology

    2007-01-01

    characterising the behaviour and ultimate load capacity of adhesively bonded joints for both composite-to-composite and composite-to-metal hybrid systems...novel hybrid joint details one of which involved perforations in the steel. The second detail employed bonding and bolting. The detail performed well...will be fabricated by four teams (3TEX, Space Micro, Tech Partnership, and Beltran) as part of the STTR Hybrid Joints Test Articles Program. Each

  7. Orion Crew Module Adapter-Structural Test Article and European S

    NASA Image and Video Library

    2017-05-09

    Inside the Neil Armstrong Operations and Checkout Building high bay at NASA's Kennedy Space Center in Florida, operations are underway to lower the Orion crew module adapter structural test article onto the European Space Agency's service module structural test article. After the hardware is attached, the structure will be packed and shipped to Lockheed Martin's Denver facility to undergo testing. The Orion spacecraft will launch atop the agency's Space Launch System rocket on Exploration Mission-1 in 2019.

  8. Buckling Test Results from the 8-Foot-Diameter Orthogrid-Stiffened Cylinder Test Article TA01. [Test Dates: 19-21 November 2008

    NASA Technical Reports Server (NTRS)

    Hilburger, Mark W.; Waters, W. Allen, Jr.; Haynie, Waddy T.

    2015-01-01

    Results from the testing of cylinder test article SBKF-P2-CYLTA01 (referred to herein as TA01) are presented. The testing was conducted at the Marshall Space Flight Center (MSFC), November 19?21, 2008, in support of the Shell Buckling Knockdown Factor (SBKF) Project.i The test was used to verify the performance of a newly constructed buckling test facility at MSFC and to verify the test article design and analysis approach used by the SBKF project researchers. TA01 is an 8-foot-diameter (96-inches), 78.0-inch long, aluminum-lithium (Al-Li), orthogrid-stiffened cylindrical shell similar to those used in current state-of-the-art launch vehicle structures and was designed to exhibit global buckling when subjected to compression loads. Five different load sequences were applied to TA01 during testing and included four sub-critical load sequences, i.e., loading conditions that did not cause buckling or material failure, and one final load sequence to buckling and collapse. The sub-critical load sequences consisted of either uniform axial compression loading or combined axial compression and bending and the final load sequence subjected TA01 to uniform axial compression. Traditional displacement transducers and strain gages were used to monitor the test article response at nearly 300 locations and an advanced digital image correlation system was used to obtain low-speed and high-speed full-field displacement measurements of the outer surface of the test article. Overall, the test facility and test article performed as designed. In particular, the test facility successfully applied all desired load combinations to the test article and was able to test safely into the postbuckling range of loading, and the test article failed by global buckling. In addition, the test results correlated well with initial pretest predictions.

  9. Forebody/Inlet of the Joint Strike Fighter Tested at Low Speeds

    NASA Technical Reports Server (NTRS)

    Johns, Albert L.

    1998-01-01

    As part of a national cooperative effort to develop a multinational fighter aircraft, a model of a Joint Strike Fighter concept was tested in several NASA Lewis Research Center wind tunnels at low speeds over a range of headwind velocities and model attitudes. This Joint Strike Fighter concept, which is scheduled to go into production in 2005, will greatly improve the range, capability, maneuverability, and survivability of fighter aircraft, and the production program could ultimately be worth $100 billion. The test program was a team effort between Lewis and Lockheed Martin Tactical Aircraft Systems. Testing was completed in September 1997, several weeks ahead of schedule, allowing Lockheed additional time to review the results and analysis data before the next test and resulting in significant cost savings for Lockheed. Several major milestones related to dynamic and steady-state data acquisition and overall model performance were reached during this model test. Results from this program will contribute to both the concept demonstration phase and the production aircraft.

  10. Design manual: Oxygen Thermal Test Article (OTTA)

    NASA Technical Reports Server (NTRS)

    Chronic, W. L.; Baese, C. L.; Conder, R. L.

    1974-01-01

    The characteristics of a cryogenic tank for storing liquid hydrogen, nitrogen, oxygen, methane, or helium for an extended period of time with minimum losses are discussed. A description of the tank and control module, assembly drawings and details of major subassemblies, specific requirements controlling development of the system, thermal concept considerations, thermal analysis methods, and a record of test results are provided. The oxygen thermal test article thermal protection system has proven that the insulation system for cryogenic vessels is effective.

  11. Characteristics of clinical shoulder research over the last decade: a review of shoulder articles in The Journal of Bone & Joint Surgery from 2004 to 2014.

    PubMed

    Gartsman, Gary M; Morris, Brent J; Unger, R Zackary; Laughlin, Mitzi S; Elkousy, Hussein A; Edwards, T Bradley

    2015-03-04

    The purpose of this study was to determine characteristics and trends in published shoulder research over the last decade in a leading orthopaedic journal. We examined all clinical shoulder articles published in The Journal of Bone & Joint Surgery from 2004 to 2014. The number of citations, authorship, academic degrees of the authors, country and institution of origin, topic, level of evidence, positive or nonpositive outcome, and inclusion of validated patient-reported outcome measures were assessed for each article. Shoulder articles that included an author with an advanced research degree (MD [Doctor of Medicine] with a PhD [Doctor of Philosophy] or other advanced degree) increased during the study period (p = 0.047). Level-I, II, and III studies were more likely to have an author with an advanced research degree, and Level-IV studies were more likely to have MDs only (p = 0.03). Overall, there was great variability of outcome measures, with at least thirty-nine different validated or nonvalidated outcome measures reported. Over the last decade, there was an improvement in the level of evidence of shoulder articles published in The Journal of Bone & Joint Surgery that corresponds with recent emphasis on evidence-based medicine. A consensus is needed in shoulder research for more consistent application of validated patient-reported outcome measurement tools. Copyright © 2015 by The Journal of Bone and Joint Surgery, Incorporated.

  12. Joint Ordnance Test Procedure (JOTP)-010 Safety and Suitability for Service Assessment Testing for Shoulder Launched Munitions

    DTIC Science & Technology

    2016-05-09

    electromagnetic environment for which they are designed to be used. These tests are performed on a powered weapon during simulated normal operation and are...010B SAFETY AND SUITABILITY FOR SERVICE ASSESSMENT TESTING FOR SHOULDER LAUNCHED MUNITIONS Joint Services Munition Safety Test Working Group JOTP...12 6.8 Test Sample Quantities .......................................................... 13 7. PRE- AND POST - TEST INSPECTIONS

  13. Development and laboratory testing of a 138-kV PPP-insulated joint for commercial application

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Walldorf, S.P.; Chu, H.; Elbadaly, H.

    1990-04-01

    This paper describes the design, development and laboratory testing of a high voltage PPP (paper polypropylene/paper laminate) insulated joint for commercial application on 138-kV PPP-insulated cable. The design approach taken is conservative and addresses the typical variations in field conditions and in skill and workmanship of the splicing. Joint construction details, including choice of connector, taping structure, and joint mechanical reinforcement, are discussed. The test criteria are described and results are presented.

  14. Laminar flow control leading edge glove flight test article development

    NASA Technical Reports Server (NTRS)

    Pearce, W. E.; Mcnay, D. E.; Thelander, J. A.

    1984-01-01

    A laminar flow control (LFC) flight test article was designed and fabricated to fit into the right leading edge of a JetStar aircraft. The article was designed to attach to the front spar and fill in approx. 70 inches of the leading edge that are normally occupied by the large slipper fuel tank. The outer contour of the test article was constrained to align with an external fairing aft of the front spar which provided a surface pressure distribution over the test region representative of an LFC airfoil. LFC is achieved by applying suction through a finely perforated surface, which removes a small fraction of the boundary layer. The LFC test article has a retractable high lift shield to protect the laminar surface from contamination by airborne debris during takeoff and low altitude operation. The shield is designed to intercept insects and other particles that could otherwise impact the leading edge. Because the shield will intercept freezing rain and ice, a oozing glycol ice protection system is installed on the shield leading edge. In addition to the shield, a liquid freezing point depressant can be sprayed on the back of the shield.

  15. J-2X Test Articles Using FDM Process

    NASA Technical Reports Server (NTRS)

    Anderson, Ted; Ruf, Joe; Steele, Phil

    2010-01-01

    This viewgraph presentation gives a brief history of the J-2X engine, along with detailed description of the material demonstrator and test articles that were created using Fused Deposition Modeling (FDM) process.

  16. Thermal-mechanical fatigue test apparatus for metal matrix composites and joint attachments

    NASA Technical Reports Server (NTRS)

    Westfall, L. J.; Petrasek, D. W.

    1985-01-01

    Two thermal-mechanical fatigue (TMF) test facilities were designed and developed, one to test tungsten fiber reinforced metal matrix composite specimens at temperature up to 1430C (2600F) and another to test composite/metal attachment bond joints at temperatures up to 760C (1400 F). The TMF facility designed for testing tungsten fiber reinforced metal matrix composites permits test specimen temperature excursions from room temperature to 1430C (2600F) with controlled heating and loading rates. A strain-measuring device measures the strain in the test section of the specimen during each heating and cooling cycle with superimposed loads. Data is collected and recorded by a computer. The second facility is designed to test composite/metal attachment bond joints and to permit heating to a maximum temperature of 760C (1400F) within 10 min and cooling to 150C (300F) within 3 min. A computer controls specimen temperature and load cycling.

  17. Thermal-mechanical fatigue test apparatus for metal matrix composites and joint attachments

    NASA Technical Reports Server (NTRS)

    Westfall, Leonard J.; Petrasek, Donald W.

    1988-01-01

    Two thermal-mechanical fatigue (TMF) test facilities were designed and developed, one to test tungsten fiber reinforced metal matrix composite specimens at temperature up to 1430C (2600F) and another to test composite/metal attachment bond joints at temperatures up to 760F (1400F). The TMF facility designed for testing tungsten fiber reinforced metal matrix composites permits test specimen temperature excursions from room temperature to 1430C (2600F) with controlled heating and loading rates. A strain-measuring device measures the strain in the test section of the specimen during each heating and cooling cycle with superimposed loads. Data is collected and recorded by a computer. The second facility is designed to test composite/metal attachment bond joints and to permit heating to a maximum temperature of 760C (1400F) within 10 min and cooling to 150C (300F) within 3 min. A computer controls specimen temperature and load cycling.

  18. Orion Crew Module Structural Test Article Transport from SLF to

    NASA Image and Video Library

    2016-11-15

    A transporter carrying the Orion crew module structural test article (STA) in its container arrives at the low bay entrance of the Neil Armstrong Operations and Checkout Building at NASA's Kennedy Space Center in Florida. The STA arrived aboard NASA's Super Guppy aircraft at the Shuttle Landing Facility operated by Space Florida. The test article will be moved inside the facility's high bay for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  19. Orion Crew Module Structural Test Article Transport from SLF to

    NASA Image and Video Library

    2016-11-15

    A transporter carrying the Orion crew module structural test article (STA) in its container arrives inside the low bay of the Neil Armstrong Operations and Checkout Building at NASA's Kennedy Space Center in Florida. The STA arrived aboard NASA's Super Guppy aircraft at the Shuttle Landing Facility operated by Space Florida. The test article will be moved inside the facility's high bay for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  20. HiL simulation in biomechanics: a new approach for testing total joint replacements.

    PubMed

    Herrmann, Sven; Kaehler, Michael; Souffrant, Robert; Rachholz, Roman; Zierath, János; Kluess, Daniel; Mittelmeier, Wolfram; Woernle, Christoph; Bader, Rainer

    2012-02-01

    Instability of artificial joints is still one of the most prevalent reasons for revision surgery caused by various influencing factors. In order to investigate instability mechanisms such as dislocation under reproducible, physiologically realistic boundary conditions, a novel test approach is introduced by means of a hardware-in-the-loop (HiL) simulation involving a highly flexible mechatronic test system. In this work, the underlying concept and implementation of all required units is presented enabling comparable investigations of different total hip and knee replacements, respectively. The HiL joint simulator consists of two units: a physical setup composed of a six-axes industrial robot and a numerical multibody model running in real-time. Within the multibody model, the anatomical environment of the considered joint is represented such that the soft tissue response is accounted for during an instability event. Hence, the robot loads and moves the real implant components according to the information provided by the multibody model while transferring back the position and resisting moment recorded. Functionality of the simulator is proved by testing the underlying control principles, and verified by reproducing the dislocation process of a standard total hip replacement. HiL simulations provide a new biomechanical testing tool for analyzing different joint replacement systems with respect to their instability behavior under realistic movements and physiological load conditions. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  1. Orion EM-1 Crew Module Structural Test Article loaded onto Guppy

    NASA Image and Video Library

    2017-04-25

    The Orion Exploration Mission-1 (EM-1) structural test article, inside its transport container, is secured in NASA's Super Guppy aircraft at the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. The test article will be transported to Lockheed Martin's Denver facility for testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission.

  2. Orion EM-1 Crew Module Structural Test Article loaded onto Guppy

    NASA Image and Video Library

    2017-04-25

    The Orion Exploration Mission-1 (EM-1) structural test article, secured inside its transport container, is loaded into NASA's Super Guppy aircraft at the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. The test article will be transported to Lockheed Martin's Denver facility for testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission.

  3. Boeing's CST-100 Structural Test Article Arrival - Boeing's Faci

    NASA Image and Video Library

    2016-12-08

    Boeing’s Structural Test Article of its CST-100 Starliner spacecraft arrives at the company’s Huntington Beach, California, facilities for evaluations. Built to the specifications of an operational spacecraft, the STA is intended to be evaluated through a series of thorough testing conditions.

  4. Adhesives: Test Method, Group Assignment, and Categorization Guide for High-Loading-Rate Applications Preparation and Testing of Single Lap Joints (Ver. 2.2, Unlimited)

    DTIC Science & Technology

    2016-04-01

    Gerard Chaney, and Charles Pergantis Weapons and Materials Research Directorate, ARL Coatings, Corrosion, and Engineered Polymers Branch (CCEPB...SUBJECT TERMS single lap joint, adhesive, sample preparation, testing, database, metadata, material pedigree, ISO 16. SECURITY CLASSIFICATION OF: 17...temperature/water immersion conditioning test for lap-joint test specimens using the test tubes and convection oven method

  5. Orion EM-1 Crew Module Structural Test Article loaded onto Guppy

    NASA Image and Video Library

    2017-04-25

    On the tarmac at the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, the Orion Exploration Mission-1 (EM-1) structural test article, secured in its transport container, is loaded into the agency's Super Guppy aircraft. The test article will be transported to Lockheed Martin's Denver facility for testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission.

  6. 21 CFR 58.47 - Facilities for handling test and control articles.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Facilities for handling test and control articles. 58.47 Section 58.47 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... for handling test and control articles. (a) As necessary to prevent contamination or mixups, there...

  7. Orion Crew Module Structural Test Article Transport from SLF to

    NASA Image and Video Library

    2016-11-15

    After arriving at the Shuttle Landing Facility operated by Space Florida at NASA's Kennedy Space Center in Florida, the agency's Super Guppy aircraft was opened and the container holding the Orion crew module structural test article (STA) was offloaded. A crane was used to lower the container for placement on a transporter. The Super Guppy has been closed. The test article will be moved to the Neil Armstrong Operations and Checkout Building high bay for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  8. Heisenberg's error-disturbance relations: A joint measurement-based experimental test

    NASA Astrophysics Data System (ADS)

    Zhao, Yuan-Yuan; Kurzyński, Paweł; Xiang, Guo-Yong; Li, Chuan-Feng; Guo, Guang-Can

    2017-04-01

    The original Heisenberg error-disturbance relation was recently shown to be not universally valid and two different approaches to reformulate it were proposed. The first one focuses on how the error and disturbance of two observables A and B depend on a particular quantum state. The second one asks how a joint measurement of A and B affects their eigenstates. Previous experiments focused on the first approach. Here we focus on the second one. First, we propose and implement an extendible method of quantum-walk-based joint measurements of noisy Pauli operators to test the error-disturbance relation for qubits introduced in the work of Busch et al. [Phys. Rev. A 89, 012129 (2014), 10.1103/PhysRevA.89.012129], where the polarization of the single photon, corresponding to a walker's auxiliary degree of freedom that is commonly known as a coin, undergoes a position- and time-dependent evolution. Then we formulate and experimentally test a universally valid state-dependent relation for three mutually unbiased observables. We therefore establish a method of testing error-disturbance relations.

  9. [Methods for evaluating diagnostic tests in Enfermedades Infecciosas y Microbiología Clínica].

    PubMed

    Ramos, J M; Hernández, I

    1998-04-01

    In the field of infectious diseases and clinical microbiology, the evaluation of diagnostic tests (DT) is an important research area. The specific difficulties of this type of research has motivated that have not caught the severity methodological of others areas of clinical research. This article try to asses and characterize the methodology of articles about DT published in Enfermedades Infecciosas y Microbiología Clínica (EIMC) journal. Forty-five articles was selected in the EIMC journal during the 1990-1996 period, because of determinate the sensitivity and specificity of different DT. Methodological standards, extensively accepted was used. In all of articles, except one (98%) the gold standard was specified yours use, however in 4 studies (9%) include the DT in the gold standard (incorporation bias). The correct description of DT was reported in 75% of cases, but only in 11% cases the reproducibility of test was evaluated. The description of source of reference population, standard of inclusion and spectrum of composition was described in 58, 33 and 40% of articles, respectively. In 33% of studies presented workup bias, only 6% commented blind-analysis of results, and 11% presented indeterminate test results. Half of the studies reported test indexes for clinical subgroups, only one article (2%) provided numerical precision for test indexes, and only 7% reported receiver operating characteristics curves. The methodological quality of DT research in the EIMC journal may improve in different aspects of design and presentation of results.

  10. Orion EM-1 Crew Module Structural Test Article Move to Birdcage

    NASA Image and Video Library

    2016-11-16

    Inside the Neil Armstrong Operations and Checkout Building at NASA’s Kennedy Space Center in Florida, the Orion crew module structural test article (STA) is secured on a test tool called the birdcage. The STA arrived aboard NASA's Super Guppy aircraft at the Shuttle Landing Facility operated by Space Florida. The test article will undergo further testing in the high bay. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  11. A Test Method for Monitoring Modulus Changes during Durability Tests on Building Joint Sealants

    Treesearch

    Christopher C. White; Donald L. Hunston; Kar Tean Tan; Gregory T. Schueneman

    2012-01-01

    The durability of building joint sealants is generally assessed using a descriptive methodology involving visual inspection of exposed specimens for defects. It is widely known that this methodology has inherent limitations, including that the results are qualitative. A new test method is proposed that provides more fundamental and quantitative information about...

  12. Orion EM-1 Crew Module Structural Test Article loaded onto Guppy

    NASA Image and Video Library

    2017-04-25

    A view from inside NASA's Super Guppy aircraft at the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, as the Orion Exploration Mission-1 (EM-1) structural test article, secured inside its transport container, is loaded into the aircraft. The test article will be transported to Lockheed Martin's Denver facility for testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission.

  13. Orion EM-1 Crew Module Structural Test Article loaded onto Guppy

    NASA Image and Video Library

    2017-04-25

    On the tarmac at the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, the agency's Super Guppy aircraft closes after the Orion Exploration Mission-1 (EM-1) structural test article, in its transport container, is secured inside. The test article will be transported to Lockheed Martin's Denver facility for testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission.

  14. Orion EM-1 Crew Module Structural Test Article loaded onto Guppy

    NASA Image and Video Library

    2017-04-25

    The Orion Exploration Mission-1 (EM-1) structural test article, secured inside its transport container, arrives at the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. The test article will be loaded into NASA's Super Guppy aircraft, in view at left, and transported to Lockheed Martin's Denver facility for testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission.

  15. Design, Fabrication, and Testing of Ceramic Joints for High Temperature SiC/SiC Composites

    NASA Technical Reports Server (NTRS)

    Singh, Mrityunjay; Lara-Curzio, Edgar

    2000-01-01

    Various issues associated with the design and mechanical evaluation of joints of ceramic matrix composites are discussed. The specific case of an affordable, robust ceramic joining technology (ARCJoinT) to join silicon carbide (CG-Nicalon(sup TM)) fiber-reinforced-chemically vapor infiltrated (CVI) silicon carbide matrix composites is addressed. Experimental results are presented for the time and temperature dependence of the shear strength of these joints in air up to 1200 C. From compression testing of double-notched joint specimens with a notch separation of 4 mm, it was found that the apparent shear strength of the joints decreased from 92 MPa at room temperature to 71 MPa at 1200 C. From shear stress-rupture testing in air at 1200 C it was found that the shear strength of the joints decreased rapidly with time from an initial shear strength of 71 to 17.5 MPa after 14.3 hr. The implications of these results in relation to the expected long-term service life of these joints in applications at elevated temperatures are discussed.

  16. Orion EM-1 Crew Module Structural Test Article Move to Birdcage

    NASA Image and Video Library

    2016-11-16

    Inside the Neil Armstrong Operations and Checkout Building at NASA’s Kennedy Space Center in Florida, Lockheed Martin technicians attach lines from a crane to the Orion crew module structural test article (STA). The STA arrived aboard NASA's Super Guppy aircraft at the Shuttle Landing Facility operated by Space Florida. The test article will be lifted out of its container and moved to a test tool called the birdcage for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  17. Orion EM-1 Crew Module Structural Test Article Move to Birdcage

    NASA Image and Video Library

    2016-11-16

    Inside the Neil Armstrong Operations and Checkout Building at NASA’s Kennedy Space Center in Florida, Lockheed Martin technicians monitor the progress as a crane lowers the Orion crew module structural test article (STA) toward a test tool called the birdcage. The STA arrived aboard NASA's Super Guppy aircraft at the Shuttle Landing Facility operated by Space Florida. The test article will be secured on the birdcage for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  18. Orion EM-1 Crew Module Structural Test Article Move to Birdcage

    NASA Image and Video Library

    2016-11-16

    Inside the Neil Armstrong Operations and Checkout Building at NASA’s Kennedy Space Center in Florida, Lockheed Martin technicians monitor the progress as a crane lowers the Orion crew module structural test article (STA) onto a test tool called the birdcage. The STA arrived aboard NASA's Super Guppy aircraft at the Shuttle Landing Facility operated by Space Florida. The test article will be secured on the birdcage for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  19. Longitudinally Jointed Edge-wise Compression Honeycomb Composite Sandwich Coupon Testing and FE Analysis: Three Methods of Strain Measurement, and Comparison

    NASA Technical Reports Server (NTRS)

    Farrokh, Babak; AbdulRahim, Nur Aida; Segal, Ken; Fan, Terry; Jones, Justin; Hodges, Ken; Mashni, Noah; Garg, Naman; Sang, Alex; Gifford, Dawn; hide

    2013-01-01

    Three means (i.e., typical foil strain gages, fiber optic sensors, and a digital image correlation (DIC) system) were implemented to measure strains on the back and front surfaces of a longitudinally jointed curved test article subjected to edge-wise compression testing, at NASA Goddard Space Flight Center, according to ASTM C364. The Pre-test finite element analysis (FEA) was conducted to assess ultimate failure load and predict strain distribution pattern throughout the test coupon. The predicted strain pattern contours were then utilized as guidelines for installing the strain measurement instrumentations. The strain gages and fiber optic sensors were bonded on the specimen at locations with nearly the same strain values, as close as possible to each other, so that, comparisons between the measured strains by strain gages and fiber optic sensors, as well as the DIC system are justified. The test article was loaded to failure (at approximately 38 kips), at the strain value of approximately 10,000mu epsilon As a part of this study, the validity of the measured strains by fiber optic sensors is examined against the strain gage and DIC data, and also will be compared with FEA predictions.

  20. Orion EM-1 Crew Module Structural Test Article loaded onto Guppy

    NASA Image and Video Library

    2017-04-25

    On the tarmac at the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, NASA and contractor workers review procedures before beginning loading of the Orion Exploration Mission-1 (EM-1) structural test article in its transport container into NASA's Super Guppy aircraft. The test article will be transported to Lockheed Martin's Denver facility for testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission.

  1. Nonlinear Analysis and Preliminary Testing Results of a Hybrid Wing Body Center Section Test Article

    NASA Technical Reports Server (NTRS)

    Przekop, Adam; Jegley, Dawn C.; Rouse, Marshall; Lovejoy, Andrew E.; Wu, Hsi-Yung T.

    2015-01-01

    A large test article was recently designed, analyzed, fabricated, and successfully tested up to the representative design ultimate loads to demonstrate that stiffened composite panels with through-the-thickness reinforcement are a viable option for the next generation large transport category aircraft, including non-conventional configurations such as the hybrid wing body. This paper focuses on finite element analysis and test data correlation of the hybrid wing body center section test article under mechanical, pressure and combined load conditions. Good agreement between predictive nonlinear finite element analysis and test data is found. Results indicate that a geometrically nonlinear analysis is needed to accurately capture the behavior of the non-circular pressurized and highly-stressed structure when the design approach permits local buckling.

  2. 13.1 Foot Diameter Fluted-Core Sandwich Composite Test Article

    NASA Image and Video Library

    2013-09-26

    White light shape and measurement of a 13.1 Foot diameter fluted-core sandwich composite test article designed by LaRC and fabricated by Boeing Under Space Act Agreement SAA1-737, Annex 14. to be tested in LaRC's combined Loads Testing System (COLTS).

  3. 13.1 Foot Diameter Fluted-Core Sandwich Composite Test Article

    NASA Image and Video Library

    2013-09-25

    White light shape and measurement of a 13.1 Foot diameter fluted-core sandwich composite test article designed by LaRC and fabricated by Boeing Under Space Act Agreement SAA1-737, Annex 14. to be tested in LaRC's combined Loads Testing System (COLTS).

  4. Ultrasonic velocity testing of steel pipeline welded joints

    NASA Astrophysics Data System (ADS)

    Carreón, Hector

    2017-04-01

    In general the ultrasonic techniques have been used to determine the mechanical properties of materials on based of their relationship with metallurgical characteristics. In this research work, the relationship between ultrasonic velocity and phased array and the microstructure of steel pipeline welded joints is investigated. Measurements of ultrasonic wave velocity were made as a function of the location across the weld. Hardness measurements were performated in an attempt to correlate with ultrasonic response. In addition, the coarse and dendritic grain structure of the weld material is extreme and unpredictably anisotropic. Thus, due to the acoustic anisotropy of the crystal itself weld material of studied joints is anisotropic, too. Such structure is no longer direction-independent to the ultrasonic wave propagation; therefore, the ultrasonic beam deflects and redirects and the wave front becomes distorted. Thus, the use of conventional ultrasonic testing techniques using fixed beam angles is very limited and the application of conventional ultrasonic phased array techniques becomes desirable.

  5. Orion EM-1 Crew Module Structural Test Article loaded onto Guppy

    NASA Image and Video Library

    2017-04-25

    The Orion Exploration Mission-1 (EM-1) structural test article, secured inside its transport container, is lifted up by crane from its transport vehicle at the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. The test article will be loaded into NASA's Super Guppy aircraft, in view at left, and transported to Lockheed Martin's Denver facility for testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission.

  6. The influence of the test setup on knee joint kinematics - A meta-analysis of tibial rotation.

    PubMed

    Hacker, Steffen P; Ignatius, Anita; Dürselen, Lutz

    2016-09-06

    The human knee is one of the most investigated joints in the human body. Various test setups exist to measure and analyse knee kinematics in vitro which differ in a wide range of parameters. The purpose of this article is to find an answer to the question if the test setup influences the kinematic outcome of studies and to what extend the results can be compared. To answer this question, we compared the tibial rotation as a function of flexion angle presented in 19 published studies. Raw data was extracted via image segmentation from the graphs depicted in these publications and the differences between the publications was analysed. Additionally, all test setups were compared regarding four aspects: method for angle calculation, system for data acquisition, loading condition and testing rig design. The resulting correlation matrix shows the influence of the test setup on the study outcome. Our results indicate that each study needs to collect its own reference data. Finally, we provide a mean internal rotation as a function of flexion angle based on more than 140 specimens tested in 14 different studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Orion EM-1 Crew Module Structural Test Article Move to Birdcage

    NASA Image and Video Library

    2016-11-16

    Inside the Neil Armstrong Operations and Checkout Building at NASA’s Kennedy Space Center in Florida, Lockheed Martin technicians prepare to attach lines from a crane to the Orion crew module structural test article (STA). The STA arrived aboard NASA's Super Guppy aircraft at the Shuttle Landing Facility operated by Space Florida. The test article will be lifted out of its container and moved to a test tool called the birdcage for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  8. Orion EM-1 Crew Module Structural Test Article Move to Birdcage

    NASA Image and Video Library

    2016-11-16

    Inside the Neil Armstrong Operations and Checkout Building at NASA’s Kennedy Space Center in Florida, Lockheed Martin technicians monitor the progress as a crane begins to lift the Orion crew module structural test article (STA) up from the base of its transport container. The STA arrived aboard NASA's Super Guppy aircraft at the Shuttle Landing Facility operated by Space Florida. The test article will be moved to a test tool called the birdcage for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  9. Orion EM-1 Crew Module Structural Test Article Move to Birdcage

    NASA Image and Video Library

    2016-11-16

    Inside the Neil Armstrong Operations and Checkout Building at NASA’s Kennedy Space Center in Florida, Lockheed Martin technicians monitor the progress as a crane moves the Orion crew module structural test article (STA) along the center aisle of the high bay. The STA arrived aboard NASA's Super Guppy aircraft at the Shuttle Landing Facility operated by Space Florida. The test article will be moved to a test tool called the birdcage for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  10. Orion EM-1 Crew Module Structural Test Article Move to Birdcage

    NASA Image and Video Library

    2016-11-16

    Inside the Neil Armstrong Operations and Checkout Building at NASA’s Kennedy Space Center in Florida, Lockheed Martin technicians monitor the progress as a crane lifts the Orion crew module structural test article (STA) up from the base of its transport container. The STA arrived aboard NASA's Super Guppy aircraft at the Shuttle Landing Facility operated by Space Florida. The test article will be moved to a test tool called the birdcage for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  11. Orion EM-1 Crew Module Structural Test Article Move to Birdcage

    NASA Image and Video Library

    2016-11-16

    Inside the Neil Armstrong Operations and Checkout Building at NASA’s Kennedy Space Center in Florida, Lockheed Martin technicians check the lines attached from a crane to the Orion crew module structural test article (STA). The STA arrived aboard NASA's Super Guppy aircraft at the Shuttle Landing Facility operated by Space Florida. The test article will be lifted out of its container and moved to a test tool called the birdcage for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  12. Orion EM-1 Crew Module Structural Test Article Move to Birdcage

    NASA Image and Video Library

    2016-11-16

    Inside the Neil Armstrong Operations and Checkout Building at NASA’s Kennedy Space Center in Florida, Lockheed Martin technicians monitor the progress as a crane lifts the Orion crew module structural test article (STA) away from the base of its transport container. The STA arrived aboard NASA's Super Guppy aircraft at the Shuttle Landing Facility operated by Space Florida. The test article will be moved to a test tool called the birdcage for further testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission, in late 2018.

  13. Orion EM-1 Crew Module Structural Test Article Prepped for Trans

    NASA Image and Video Library

    2017-04-24

    Inside the Neil Armstrong Operations and Checkout Building high bay at NASA's Kennedy Space Center in Florida, technicians secure the transport container with the Orion Exploration Mission-1 (EM-1) structural test article onto a transport vehicle for the move to the Shuttle Landing Facility. The test article will be loaded in NASA's Super Guppy airplane and transported to Lockheed Martin's Denver facility for testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission.

  14. Orion EM-1 Crew Module Structural Test Article Prepped for Trans

    NASA Image and Video Library

    2017-04-24

    Inside the Neil Armstrong Operations and Checkout Building high bay at NASA's Kennedy Space Center in Florida, the Orion Exploration Mission-1 (EM-1) structural test article inside its transport container, is secured onto a transport vehicle for the move to the Shuttle Landing Facility. The test article will be loaded in NASA's Super Guppy airplane and transported to Lockheed Martin's Denver facility for testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission.

  15. Orion EM-1 Crew Module Structural Test Article Prepped for Trans

    NASA Image and Video Library

    2017-04-24

    Inside the Neil Armstrong Operations and Checkout Building high bay at NASA's Kennedy Space Center in Florida, technicians secure the Orion Exploration Mission-1 (EM-1) structural test article in its transport container onto a transport vehicle for the move to the Shuttle Landing Facility. The test article will be loaded in NASA's Super Guppy airplane and transported to Lockheed Martin's Denver facility for testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission.

  16. Orion EM-1 Crew Module Structural Test Article Prepped for Trans

    NASA Image and Video Library

    2017-04-24

    Inside the Neil Armstrong Operations and Checkout Building high bay at NASA's Kennedy Space Center in Florida, the Orion Exploration Mission-1 (EM-1) structural test article, secured inside its transport container, is lowered onto a transport vehicle for the move to the Shuttle Landing Facility. The test article will be loaded in NASA's Super Guppy airplane and transported to Lockheed Martin's Denver facility for testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission.

  17. Diagnostic test accuracy and prevalence inferences based on joint and sequential testing with finite population sampling.

    PubMed

    Su, Chun-Lung; Gardner, Ian A; Johnson, Wesley O

    2004-07-30

    The two-test two-population model, originally formulated by Hui and Walter, for estimation of test accuracy and prevalence estimation assumes conditionally independent tests, constant accuracy across populations and binomial sampling. The binomial assumption is incorrect if all individuals in a population e.g. child-care centre, village in Africa, or a cattle herd are sampled or if the sample size is large relative to population size. In this paper, we develop statistical methods for evaluating diagnostic test accuracy and prevalence estimation based on finite sample data in the absence of a gold standard. Moreover, two tests are often applied simultaneously for the purpose of obtaining a 'joint' testing strategy that has either higher overall sensitivity or specificity than either of the two tests considered singly. Sequential versions of such strategies are often applied in order to reduce the cost of testing. We thus discuss joint (simultaneous and sequential) testing strategies and inference for them. Using the developed methods, we analyse two real and one simulated data sets, and we compare 'hypergeometric' and 'binomial-based' inferences. Our findings indicate that the posterior standard deviations for prevalence (but not sensitivity and specificity) based on finite population sampling tend to be smaller than their counterparts for infinite population sampling. Finally, we make recommendations about how small the sample size should be relative to the population size to warrant use of the binomial model for prevalence estimation. Copyright 2004 John Wiley & Sons, Ltd.

  18. SLS INTERIM CRYOGENIC PROPULSION STAGE TEST ARTICLE ARRIVAL

    NASA Image and Video Library

    2016-06-19

    SLS INTERIM CRYOGENIC PROPULSION STAGE TEST ARTICLE ARRIVES AT WEST DOCK ON SHIELDS ROAD AND IS OFF LOADED FROM BARGEUAH ENGINEERING STUDENT ROBERT HILLAN TALKS TO SPACE STATION CREW MEMBERS ABOUT HIS WINNING 3-D PRINTED TOOL DESIGNED FOR USE ON ISS, AND IS INTERVIEWED BY LOCAL MEDIA

  19. SLS Engine Section Test Article Arrives at Marshall on NASA Barge Pegasus

    NASA Image and Video Library

    2017-05-16

    The NASA barge Pegasus made it’s first trip to NASA’s Marshall Space Flight Center in Huntsville, Alabama on May 15. It arrived carrying the first piece of Space Launch System hardware built at NASA's Michoud Assembly Facility in New Orleans. The barge left Michoud on April 28 with the core stage engine section test article, traveling 1,240 miles by river to Marshall. The rocket's engine section is the bottom of the core stage and houses the four RS-25 engines. The engine section test article will be moved to Marshall’s Building 4619 where it will be tested. The bottom part of the test article is structurally the same as the engine section that will be flown as part of the SLS core stage. The shiny metal top part simulates the rocket's liquid hydrogen tank, which is the fuel tank that joins to the engine section. The test article will endure tests that pull, push, and bend it, subjecting it to millions of pounds of force. This ensures the structure can withstand the incredible stresses produced by the 8.8 million pounds of thrust during launch and ascent.

  20. Orion EM-1 Crew Module Structural Test Article Prepped for Trans

    NASA Image and Video Library

    2017-04-24

    Inside the Neil Armstrong Operations and Checkout Building high bay at NASA's Kennedy Space Center in Florida, the Orion Exploration Mission-1 (EM-1) structural test article is secured inside its transport container. A crane is used to move the container toward a transport vehicle for the move to the Shuttle Landing Facility. The test article will be loaded in NASA's Super Guppy airplane and transported to Lockheed Martin's Denver facility for testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission.

  1. PFCA Article Testing

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA) has established an ongoing effort to quantify possible changes in levels of perfluorinated chemicals (PFCs) in articles of commerce (AOCs). Temporal trends in the concentrations of selected PFCs, including perfluorooctanoic acid (PFO...

  2. [Eradication of Staphylococcus aureus in carrier patients undergoing joint arthroplasty].

    PubMed

    Barbero Allende, José M; Romanyk Cabrera, Juan; Montero Ruiz, Eduardo; Vallés Purroy, Alfonso; Melgar Molero, Virginia; Agudo López, Rosa; Gete García, Luis; López Álvarez, Joaquín

    2015-02-01

    Prosthetic joint infection (PJI) is a complication with serious repercussions and its main cause is Staphylococcus aureus. The purpose of this study is to determine whether decolonization of S.aureus carriers helps to reduce the incidence of PJI by S.aureus. An S.aureus screening test was performed on nasal carriers in patients undergoing knee or hip arthroplasty between January and December 2011. Patients with a positive test were treated with intranasal mupirocin and chlorhexidine soap 5 days. The incidence of PJI was compared with patients undergoing the same surgery between January and December 2010. A total of 393 joint replacements were performed in 391 patients from the control group, with 416 joint replacements being performed in the intervention group. Colonization study was performed in 382 patients (91.8%), of which 102 were positive (26.7%) and treated. There was 2 PJI due S.aureus compared with 9 in the control group (0.5% vs 2.3%, odds ratio [OR]: 0.2, 95% confidence interval [CI]: 0.4 to 2.3, P=.04). In our study, the detection of colonization and eradication of S.aureus carriers achieved a significant decrease in PJI due to S.aureus compared to a historical group. Copyright © 2013 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  3. Design, fabrication and test of graphite/polyimide composite joints and attachments for advanced aerospace vehicles

    NASA Technical Reports Server (NTRS)

    Koumal, D. E.

    1979-01-01

    The design and evaluation of built-up attachments and bonded joint concepts for use at elevated temperatures is documented. Joint concept screening, verification of GR/PI material, fabrication of design allowables panels, definition of test matrices, and analysis of bonded and bolted joints are among the tasks completed. The results provide data for the design and fabrication of lightly loaded components for advanced space transportation systems and high speed aircraft.

  4. Solid Rocket Booster Structural Test Article

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The structural test article to be used in the solid rocket booster (SRB) structural and load verification tests is being assembled in a high bay building of the Marshall Space Flight Center (MSFC). The Shuttle's two SRB's are the largest solids ever built and the first designed for refurbishment and reuse. Standing nearly 150-feet high, the twin boosters provide the majority of thrust for the first two minutes of flight, about 5.8 million pounds, augmenting the Shuttle's main propulsion system during liftoff. The major design drivers for the solid rocket motors (SRM's) were high thrust and reuse. The desired thrust was achieved by using state-of-the-art solid propellant and by using a long cylindrical motor with a specific core design that allows the propellant to burn in a carefully controlled marner. At burnout, the boosters separate from the external tank and drop by parachute to the ocean for recovery and subsequent refurbishment.

  5. Effects of Novel Guidance Tubing Gait on Electromyographic Neuromuscular Imbalance and Joint Angular Kinematics During Locomotion in Hemiparetic Stroke Patients.

    PubMed

    Lee, Jeong J; You, Joshua Sung H

    2017-12-01

    To compare the immediate effects of conventional treadmill gait and guidance tubing gait (GTG) on electromyographic neuromuscular imbalance and knee joint kinematics in hemiparetic gait. Case-control study. University medical center. Participants (N=33; 19 men, 14 women) were patients with hemiparetic stroke (n=18 [experimental]; mean age ± SD, 39.2±16.8y) and healthy controls (n=15; mean age ± SD, 26.3±2.6y). The GTG was provided for approximately 30 minutes and involved application of an assistive guidance force using the tubing, specifically to improve knee joint stabilization during midstance and increase knee joint flexion during midswing phase. Clinical tests included the Korean Mini-Mental State Examination, Modified Ashworth Scale, Berg Balance Scale, manual muscle test, and knee joint range of motion and sensory tests. Knee joint muscle electromyographic and kinematic analyses were determined at pretest and posttest. After the intervention, the experimental group showed significantly greater improvements in balanced quadriceps and hamstring electromyographic coactivation and knee joint kinematics relative to the control group (P=.005). The GTG intervention decreased overactive hamstring activity (P=.018) and reciprocally increased quadriceps activity (P<.001). The knee joint kinematic analysis showed significant changes in the hemiparetic stroke group (P=.004). This study demonstrates the effectiveness of the tubing gait condition to restore knee joint muscle imbalance and kinematics in individuals with hemiparetic stroke who present with an abnormal hyperextension knee gait. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  6. Joint excitation synchronization characteristics of fatigue test for offshore wind turbine blade

    NASA Astrophysics Data System (ADS)

    Zhang, Lei-an; Yu, Xiang-yong; Wei, Xiu-ting; Liu, Wei-sheng

    2018-02-01

    In the case of the stiffness of offshore wind turbine blade is relatively large, the joint excitation device solves the problem of low accuracy of bending moment distribution, insufficient driving ability and long fatigue test period in single-point loading. In order to study the synchronous characteristics of joint excitation system, avoid blade vibration disturbance. First, on the base of a Lagrange equation, a mathematical model of combined excitation is formulated, and a numerical analysis of vibration synchronization is performed. Then, the model is constructed via MATLAB/Simulink, and the effect of the phase difference on the vibration synchronization characteristics is obtained visually. Finally, a set of joint excitation platform for the fatigue test of offshore wind turbine blades are built. The parameter measurement scheme is given and the correctness of the joint excitation synchronization in the simulation model is verified. The results show that when the rotational speed difference is 2 r/min, 30 r/min, the phase difference is 0, π/20, π/8 and π/4, as the rotational speed difference and the phase difference increase, the time required for the blade to reach a steady state is longer. When the phase difference is too large, the electromechanical coupling can no longer make the joint excitation device appear self-synchronizing phenomenon, so that the value of the phase difference develops toward a fixed value (not equal to 0), and the blade vibration disorder is serious, at this time, the effect of electromechanical coupling must be eliminated. The research results provide theoretical basis for the subsequent decoupling control algorithm and synchronization control strategy, and have good application value.

  7. Dynamic testing of a two-dimensional box truss beam

    NASA Technical Reports Server (NTRS)

    White, Charles W.

    1987-01-01

    Testing to determine the effects of joint freeplay and pretensioning of diagonal members on the dynamic characteristics of a two-dimensional box truss beam was conducted. The test article was ten bays of planar truss suspended by long wires at each joint. Each bay measured 2 meters per side. Pins of varying size were used to simulate various joint freeplay conditions. Single-point random excitation was the primary method of test. The rational fraction polynomial method was used to extract modal characteristics from test data. A finite element model of the test article was generated from which modal characteristics were predicted. These were compared with those obtained from tests. With the exception of the fundamental mode, correlation of theoretical and experimental results was poor, caused by the resonant coupling of local truss member bending modes with global truss beam modes. This coupling introduced many modes in the frequency range of interest whose frequencies were sensitive to joint boundary conditions. It was concluded that local/global coupling must be avoided in the frequency range where accurate modal characteristics are required.

  8. Hot wire anemometer measurements in the unheated air flow tests of the SRB nozzle-to-case joint

    NASA Technical Reports Server (NTRS)

    Ramachandran, N.

    1988-01-01

    Hot-Wire Anemometer measurements made in the Solid Rocket Booster (SRB) nozzle-to-case joint are discussed. The study was undertaken to glean additional information on the circumferential flow induced in the SRB nozzle joint and the effect of this flow on the insulation bonding flaws. The tests were conducted on a full-scale, 2-D representation of a 65-in long segment of the SRB nozzle joint, with unheated air as the working fluid. Both the flight Mach number and Reynolds number were matched simultaneously and different pressure gradients imposed along the joint face were investigated. Hot-wire anemometers were used to obtain velocity data for different joint gaps and debond configurations. The procedure adopted for hot-wire calibration and use is outlined and the results from the tests summarized.

  9. Orion EM-1 Crew Module Structural Test Article Prepped for Trans

    NASA Image and Video Library

    2017-04-24

    Inside the Neil Armstrong Operations and Checkout Building high bay at NASA's Kennedy Space Center in Florida, the Orion Exploration Mission-1 (EM-1) structural test article is secured inside its transport container. Technicians monitor the progress as a crane is used to move the container toward a transport vehicle for the move to the Shuttle Landing Facility. The test article will be loaded in NASA's Super Guppy airplane and transported to Lockheed Martin's Denver facility for testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission.

  10. An accelerated exposure and testing apparatus for building joint sealants

    NASA Astrophysics Data System (ADS)

    White, C. C.; Hunston, D. L.; Tan, K. T.; Hettenhouser, J.; Garver, J. D.

    2013-09-01

    The design, fabrication, and implementation of a computer-controlled exposure and testing apparatus for building joint sealants are described in this paper. This apparatus is unique in its ability to independently control and monitor temperature, relative humidity, ultraviolet (UV) radiation, and mechanical deformation. Each of these environmental factors can be controlled precisely over a wide range of conditions during periods of a month or more. Moreover, as controlled mechanical deformations can be generated, in situ mechanical characterization tests can be performed without removing specimens from the chamber. Temperature and humidity were controlled during our experiments via a precision temperature regulator and proportional mixing of dry and moisture-saturated air; while highly uniform UV radiation was attained by attaching the chamber to an integrating sphere-based radiation source. A computer-controlled stepper motor and a transmission system were used to provide precise movement control. The reliability and effectiveness of the apparatus were demonstrated on a model sealant material. The results clearly show that this apparatus provides an excellent platform to study the long-term durability of building joint sealants.

  11. An accelerated exposure and testing apparatus for building joint sealants.

    PubMed

    White, C C; Hunston, D L; Tan, K T; Hettenhouser, J; Garver, J D

    2013-09-01

    The design, fabrication, and implementation of a computer-controlled exposure and testing apparatus for building joint sealants are described in this paper. This apparatus is unique in its ability to independently control and monitor temperature, relative humidity, ultraviolet (UV) radiation, and mechanical deformation. Each of these environmental factors can be controlled precisely over a wide range of conditions during periods of a month or more. Moreover, as controlled mechanical deformations can be generated, in situ mechanical characterization tests can be performed without removing specimens from the chamber. Temperature and humidity were controlled during our experiments via a precision temperature regulator and proportional mixing of dry and moisture-saturated air; while highly uniform UV radiation was attained by attaching the chamber to an integrating sphere-based radiation source. A computer-controlled stepper motor and a transmission system were used to provide precise movement control. The reliability and effectiveness of the apparatus were demonstrated on a model sealant material. The results clearly show that this apparatus provides an excellent platform to study the long-term durability of building joint sealants.

  12. Comparative biomechanical analysis of current microprocessor-controlled prosthetic knee joints.

    PubMed

    Bellmann, Malte; Schmalz, Thomas; Blumentritt, Siegmar

    2010-04-01

    To investigate and identify functional differences of 4 microprocessor-controlled prosthetic knee joints (C-Leg, Hybrid Knee [also called Energy Knee], Rheo Knee, Adaptive 2). Tested situations were walking on level ground, on stairs and ramps; additionally, the fall prevention potentials for each design were examined. The measuring technology used included an optoelectronic camera system combined with 2 forceplates as well as a mobile spiroergometric system. The study was conducted in a gait laboratory. Subjects with unilateral transfemoral amputations (N=9; mobility grade, 3-4; age, 22-49y) were tested. Participants were fitted and tested with 4 different microprocessor-controlled knee joints. Static prosthetic alignment, time distance parameters, kinematic and kinetic data and metabolic energy consumption. Compared with the Hybrid Knee and the Adaptive 2, the C-Leg offers clear advantages in the provision of adequate swing phase flexion resistances and terminal extension damping during level walking at various speeds, especially at higher walking speeds. The Rheo Knee provides sufficient terminal extension; however, swing phase flexion resistances seem to be too low. The values for metabolic energy consumption show only slight differences during level walking. The joint resistances generated for descending stairs and ramps relieve the contralateral side to varying degrees. When walking on stairs, safety-relevant technical differences between the investigated joint types can be observed. Designs with adequate internal resistances offer stability advantages when the foot is positioned on the step. Stumble recovery tests reveal that the different knee joint designs vary in their effectiveness in preventing the patient from falling. The patient benefits provided by the investigated electronic prosthetic knee joints differ considerably. The C-Leg appears to offer the amputee greater functional and safety-related advantages than the other tested knee joints. Reduced

  13. GO1 Inert Test Article Captive Carry

    NASA Image and Video Library

    2018-01-10

    Generation Orbit Launch Services, Inc. (GO) completed the GO1 Inert Test Article captive carry flight test at NASA’s Armstrong Flight Research Center in December. Under a public-private partnership with NASA, GO developed the GO1-ITA, a mass properties and outer mold line simulator for the GO1 hypersonic flight testbed and earned NASA airworthiness approval for flight on NASA’s C-20a. NASA’s C-20a was originally modified to add a centerline hard point to carry the Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) pod. Together with the NASA Armstrong team, a campaign of three flight tests was conducted, successfully completing all test objectives including clearing the operational flight envelope of the C-20a with the GO1-ITA mounted to the centerline hard point, and demonstrated the unique launch maneuver designed for air launch of the GO1 on operational flights starting in 2019. Data collected during the campaign will be used to validate models and inform the ongoing design and development of GO1.

  14. Movement of the sacroiliac joint during the Active Straight Leg Raise test in patients with long-lasting severe sacroiliac joint pain.

    PubMed

    Kibsgård, Thomas J; Röhrl, Stephan M; Røise, Olav; Sturesson, Bengt; Stuge, Britt

    2017-08-01

    The Active Straight Leg Raise is a functional test used in the assessment of pelvic girdle pain, and has shown to have good validity, reliability and responsiveness. The Active Straight Leg Raise is considered to examine the patients' ability to transfer load through the pelvis. It has been hypothesized that patients with pelvic girdle pain lack the ability to stabilize the pelvic girdle, probably due to instability or increased movement of the sacroiliac joint. This study examines the movement of the sacroiliac joints during the Active Straight Leg Raise in patients with pelvic girdle pain. Tantalum markers were inserted in the dorsal sacrum and ilium of 12 patients with long-lasting pelvic girdle pain scheduled for sacroiliac joint fusion surgery. Two to three weeks later movement of the sacroiliac joints during the Active Straight Leg Raise was measured with radiostereometric analysis. Small movements were detected. There was larger movement of the sacroiliac joint of the rested leg's sacroiliac joint compared to the lifted leg's side. A mean backward rotation of 0.8° and inward tilt of 0.3° were seen in the rested leg's sacroiliac joint. The movements of the sacroiliac joints during the Active Straight Leg Raise are small. There was a small backward rotation of the innominate bone relative to sacrum on the rested leg's side. Our findings contradict an earlier understanding that a forward rotation of the lifted leg's innominate occur while performing the Active Straight Leg Raise. Copyright © 2017. Published by Elsevier Ltd.

  15. Photoelastic analysis in respect to failure mechanics problems of power plant articles and units

    NASA Astrophysics Data System (ADS)

    Korikhin, N. V.; Eigenson, S. N.

    2009-02-01

    The results of strength tests of some critical articles and units of power plants, i.e., a reactor vessel, threaded connection of vessel split, pressure header with straight nipple, turbomachine shaft, and T-weld joint of stator and rotor parts, of turbomachines are presented.

  16. Functional assessments of the knee joint biomechanics by using pendulum test in adults with Down syndrome

    PubMed Central

    Casabona, Antonino; Valle, Maria Stella; Pisasale, Mariangela; Pantò, Maria Rosita

    2012-01-01

    In this study, we assessed kinematics and viscoelastic features of knee joint in adults with Down syndrome (DS) by means of the Wartenberg pendulum test. This test allows the measuring of the kinematics of the knee joint during passive pendular motion of leg under the influence of gravity. In addition, by a combination of kinematic and anthropometric data, pendulum test provides estimates of joint viscoelastic properties by computing damping and stiffness coefficients. To monitor the occurrences of muscle activation, the surface electromyogram (EMG) of muscle rectus femoris was recorded. The experimental protocol was performed in a group of 10 adults with DS compared with 10 control adults without DS. Joint motion amplitude, velocity, and acceleration of the leg during the first knee flexion significantly decreased in persons with DS with respect to those without DS. This behavior was associated with the activation of rectus femoris in subjects with DS that resulted in increasing of joint resistance shortly after the onset of the first leg flexion. The EMG bursts mostly occurred between 50 and 150 ms from the leg flexion onset. During the remaining cycles of pendular motion, persons with DS exhibited passive leg oscillations with low tonic EMG activity and reduced damping coefficient compared with control subjects. These results suggest that adults with DS might perform preprogrammed contractions to increase joint resistance and compensate for inherent joint instability occurring for quick and unpredictable perturbations. The reduction of damping coefficients observed during passive oscillations could be a predictor of muscle hypotonia. PMID:22995394

  17. SPE propulsion electrolyzer for NASA's integrated propulsion test article

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Hamilton Standard has delivered a 3000 PSI SPE Propulsion Electrolyzer Stack and Special Test Fixture to the NASA Lyndon B. Johnson Space Center (JSC) Integrated Propulsion Test Article (IPTA) program in June 1990, per contract NAS9-18030. This prototype unit demonstrates the feasibility of SPE-high pressure water electrolysis for future space applications such as Space Station propulsion and Lunar/Mars energy storage. The SPE-Propulsion Electrolyzer has met or exceeded all IPTA program goals. It continues to function as the primary hydrogen and oxygen source for the IPTA test bed at the NASA/JSC Propulsion and Power Division Thermochemical Test Branch.

  18. Characteristics of Laser Beam and Friction Stir Welded AISI 409M Ferritic Stainless Steel Joints

    NASA Astrophysics Data System (ADS)

    Lakshminarayanan, A. K.; Balasubramanian, V.

    2012-04-01

    This article presents the comparative evaluation of microstructural features and mechanical properties of friction stir welded (solid-state) and laser beam welded (high energy density fusion welding) AISI 409M grade ferritic stainless steel joints. Optical microscopy, microhardness testing, transverse tensile, and impact tests were performed. The coarse ferrite grains in the base material were changed to fine grains consisting duplex structure of ferrite and martensite due to the rapid cooling rate and high strain induced by severe plastic deformation caused by frictional stirring. On the other hand, columnar dendritic grain structure was observed in fusion zone of laser beam welded joints. Tensile testing indicates overmatching of the weld metal relative to the base metal irrespective of the welding processes used. The LBW joint exhibited superior impact toughness compared to the FSW joint.

  19. Structural Benchmark Creep Testing for Microcast MarM-247 Advanced Stirling Convertor E2 Heater Head Test Article SN18

    NASA Technical Reports Server (NTRS)

    Krause, David L.; Brewer, Ethan J.; Pawlik, Ralph

    2013-01-01

    This report provides test methodology details and qualitative results for the first structural benchmark creep test of an Advanced Stirling Convertor (ASC) heater head of ASC-E2 design heritage. The test article was recovered from a flight-like Microcast MarM-247 heater head specimen previously used in helium permeability testing. The test article was utilized for benchmark creep test rig preparation, wall thickness and diametral laser scan hardware metrological developments, and induction heater custom coil experiments. In addition, a benchmark creep test was performed, terminated after one week when through-thickness cracks propagated at thermocouple weld locations. Following this, it was used to develop a unique temperature measurement methodology using contact thermocouples, thereby enabling future benchmark testing to be performed without the use of conventional welded thermocouples, proven problematic for the alloy. This report includes an overview of heater head structural benchmark creep testing, the origin of this particular test article, test configuration developments accomplished using the test article, creep predictions for its benchmark creep test, qualitative structural benchmark creep test results, and a short summary.

  20. The Growth of Multi-Site Fatigue Damage in Fuselage Lap Joints

    NASA Technical Reports Server (NTRS)

    Piascik, Robert S.; Willard, Scott A.

    1999-01-01

    Destructive examinations were performed to document the progression of multi-site damage (MSD) in three lap joint panels that were removed from a full scale fuselage test article that was tested to 60,000 full pressurization cycles. Similar fatigue crack growth characteristics were observed for small cracks (50 microns to 10 mm) emanating from counter bore rivets, straight shank rivets, and 100 deg counter sink rivets. Good correlation of the fatigue crack growth data base obtained in this study and FASTRAN Code predictions show that the growth of MSD in the fuselage lap joint structure can be predicted by fracture mechanics based methods.

  1. Summary of LaRC 2-inch Erectable Joint Hardware Heritage Test Data

    NASA Technical Reports Server (NTRS)

    Dorsey, John T.; Watson, Judith J.

    2016-01-01

    As the National Space Transportation System (STS, also known as the Space Shuttle) went into service during the early 1980's, NASA envisioned many missions of exploration and discovery that could take advantage of the STS capabilities. These missions included: large orbiting space stations, large space science telescopes and large spacecraft for manned missions to the Moon and Mars. The missions required structures that were significantly larger than the payload volume available on the STS. NASA Langley Research Center (LaRC) conducted studies to design and develop the technology needed to assemble the large space structures in orbit. LaRC focused on technology for erectable truss structures, in particular, the joint that connects the truss struts at the truss nodes. When the NASA research in large erectable space structures ended in the early 1990's, a significant amount of structural testing had been performed on the LaRC 2-inch erectable joint that was never published. An extensive set of historical information and data has been reviewed and the joint structural testing results from this historical data are compiled and summarized in this report.

  2. SLS Intertank Test Article, ITA, is attached to crosshead of loa

    NASA Image and Video Library

    2018-04-04

    SLS Intertank Test Article, ITA, is attached to crosshead of load test Annex, Bldg. 4619, and removed from bed of KMAG transporter. Rob Ziegler, L, and Roger Myrick, R, of Aerie Aerospace attach load lines to Aft Load Ring of Intertank Test Articlle

  3. Low Cost Propulsion Technology Testing at the Stennis Space Center: Propulsion Test Article and the Horizontal Test Facility

    NASA Technical Reports Server (NTRS)

    Fisher, Mark F.; King, Richard F.; Chenevert, Donald J.

    1998-01-01

    The need for low cost access to space has initiated the development of low cost liquid rocket engine and propulsion system hardware at the Marshall Space Flight Center. This hardware will be tested at the Stennis Space Center's B-2 test stand. This stand has been reactivated for the testing of the Marshall designed Fastrac engine and the Propulsion Test Article. The RP-1 and LOX engine is a turbopump fed gas generator rocket with an ablative nozzle which has a thrust of 60,000 lbf. The Propulsion Test Article (PTA) is a test bed for low cost propulsion system hardware including a composite RP-I tank, flight feedlines and pressurization system, stacked in a booster configuration. The PTA is located near the center line of the B-2 test stand, firing vertically into the water cooled flame deflector. A new second position on the B-2 test stand has been designed and built for the horizontal testing of the Fastrac engine in direct support of the X-34 launch vehicle. The design and integration of these test facilities as well as the coordination which was required between the two Centers is described and lessons learned are provided. The construction of the horizontal test position is discussed in detail. The activation of these facilities is examined and the major test milestones are described.

  4. Dot Projection Photogrammetric Technique for Shape Measurements of Aerospace Test Articles

    NASA Technical Reports Server (NTRS)

    Jones, Thomas W.; Pappa, Richard S.

    2002-01-01

    Results from initial laboratory investigations with the dot projection photogrammetric technique are presented for three wind-tunnel test articles with a range of surface scattering and reflection properties. These test articles are a semispan model and a micro air vehicle with a latex wing that are both diffusely reflecting, and a highly polished specularly reflecting model used for high Reynolds number testing. Results using both white light and laser illumination are presented. Some of the advantages and limitations of the dot projection technique are discussed. Although a desirable final outcome of this research effort is the characterization of dynamic behavior, only static laboratory results are presented in this preliminary effort.

  5. Effect of process parameters on microstructure and mechanical properties of friction stir welded joints: A review

    NASA Astrophysics Data System (ADS)

    Wanare, S. P.; Kalyankar, V. D.

    2018-04-01

    Friction stir welding is emerging as a promising technique for joining of lighter metal alloys due to its several advantages over conventional fusion welding processes such as low thermal distortion, good mechanical properties, fine weld joint microstructure, etc. This review article mainly focuses on analysis of microstructure and mechanical properties of friction stir welded joints. Various microstructure characterization techniques used by previous researchers such as optical microscopes, x-ray diffraction, electron probe microscope, transmission electron microscope, scanning electron microscopes with electron back scattered diffraction, electron dispersive microscopy, etc. are thoroughly overviewed and their results are discussed. The effects of friction stir welding process parameters such as tool rotational speed, welding speed, tool plunge depth, axial force, tool shoulder diameter to tool pin diameter ratio, tool geometry etc. on microstructure and mechanical properties of welded joints are studied and critical observations are noted down. The microstructure examination carried out by previous researchers on various zones of welded joints such as weld zone, heat affected zone and base metal are studied and critical remarks have been presented. Mechanical performances of friction stir welded joints based on tensile test, micro-hardness test, etc. are discussed. This article includes exhaustive literature review of standard research articles which may become ready information for subsequent researchers to establish their line of action.

  6. Together I Can! Joint Attention Boosts 3- to 4-Year-Olds' Performance in a Verbal False-Belief Test.

    PubMed

    Psouni, Elia; Falck, Andreas; Boström, Leni; Persson, Martin; Sidén, Lisa; Wallin, Maria

    2018-04-20

    Effects of joint attention were addressed on 3- to 4-year-olds' performance in a verbal false-Belief Test (FBT), featuring the experimenter as co-watcher rather than narrator. In two experiments, children (N = 183) watched a filmed-FBT jointly with a test leader, disjointed from a test leader, or alone. Children attending jointly with a test leader were more likely to pass the FBT compared with normative data and to spontaneously recall information indicating false-belief understanding, suggesting that joint attention strengthens the plausibility of the FBT and renders plot-critical information more salient. In a third experiment (N = 59), results were replicated using a typical, image-based FBT. Overall findings highlight the profound impact of experimenter as social context in verbal FBTs, and link recall of specific story features to false-belief understanding. © 2018 Society for Research in Child Development.

  7. Gatecrashing the Oasis? A Joint Doctoral Dissertation Play

    ERIC Educational Resources Information Center

    Gale, Ken; Speedy, Jane; Wyatt, Jonathan

    2010-01-01

    This article explores the institutional and individual struggles surrounding the submission for examination of a jointly authored doctoral dissertation at a U.K. civic university. Two of the article's authors (Gale and Wyatt) were the dissertation's authors, and Speedy, the article's third author, is their supervisor. Joint doctoral dissertations…

  8. Ultrasonic Nondestructive Evaluation of PRSEUS Pressure Cube Article in Support of Load Test to Failure

    NASA Technical Reports Server (NTRS)

    Johnston, Patrick H.

    2013-01-01

    The PRSEUS Pressure Cube Test was a joint development effort between the Boeing Company and NASA Langley Research Center, sponsored in part by the Environmentally Responsible Aviation Project and Boeing internal R&D. This Technical Memorandum presents the results of ultrasonic inspections in support of the PRSEUS Pressure Cube Test, and is a companion document with the NASA test report and a report on the acoustic emission measurements made during the test.

  9. Gen. Paul J. Selva > Joint Chiefs of Staff > Article View

    Science.gov Websites

    aircraft systems and executive officer, Deputy Chief of Staff, Plans and Resources, Headquarters Strategic Facebook on Flickr Joint Chiefs Army Chief of Staff Marine Corps Commandant Chief of Naval Operations Air Force Chief of Staff Chief of National Guard Bureau Biographies Directorates Directorates of Management

  10. Joint line tenderness and McMurray tests for the detection of meniscal lesions: what is their real diagnostic value?

    PubMed

    Galli, Marco; Ciriello, Vincenzo; Menghi, Amerigo; Aulisa, Angelo G; Rabini, Alessia; Marzetti, Emanuele

    2013-06-01

    To assess the interobserver concordance of the joint line tenderness (JLT) and McMurray tests, and to determine their diagnostic efficiency for the detection of meniscal lesions. Prospective observational study. Orthopedics outpatient clinic, university hospital. Patients (N=60) with suspected nonacute meniscal lesions who underwent knee arthroscopy. Not applicable. Patients were examined by 3 independent observers with graded levels of experience (>10y, 3y, and 4mo of practice). The interobserver concordance was assessed by Cohen-Fleiss κ statistics. Accuracy, negative and positive predictive values for prevalence 10% to 90%, positive (LR+) and negative (LR-) likelihood ratios, and the Bayesian posttest probability with a positive or negative result were also determined. The diagnostic value of the 2 tests combined was assessed by logistic regression. Arthroscopy was used as the reference test. No interobserver concordance was determined for the JLT. The McMurray test showed higher interobserver concordance, which improved when judgments by the less experienced examiner were discarded. The whole series studied by the "best" examiner (experienced orthopedist) provided the following values: (1) JLT: sensitivity, 62.9%; specificity, 50%; LR+, 1.26; LR-, .74; (2) McMurray: sensitivity, 34.3%; specificity, 86.4%; LR+, 2.52; LR-, .76. The combination of the 2 tests did not offer advantages over the McMurray alone. The JLT alone is of little clinical usefulness. A negative McMurray test does not modify the pretest probability of a meniscal lesion, while a positive result has a fair predictive value. Hence, in a patient with a suspected meniscal lesion, a positive McMurray test indicates that arthroscopy should be performed. In case of a negative result, further examinations, including imaging, are needed. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  11. Analysis of muscle activity and ankle joint movement during the side-hop test.

    PubMed

    Yoshida, Masahiro; Taniguchi, Keigo; Katayose, Masaki

    2011-08-01

    Functional performance tests (FPTs) that consist of movements, such as hopping, landing, and cutting, provide useful measurements. Although some tests have been established for kinematic studies of the knee joint, very few tests have been established for the ankle joint. To use the FPT as a test battery for patients with an ankle sprain, it is necessary to document typical patterns of muscle activation and range of motion (ROM) of the ankle joint during FPTs. Therefore, the purpose of this study was to investigate the pattern of the ROM of the ankle inversion/eversion and the muscle activity of the peroneus longus muscle (PL) and the tibial anterior muscle (TA) in normal subjects during the side-hop test. To emphasize the characteristics of ROM and electromyography (EMG) at each phase, the side-hop tests were divided into 4 phases: lateral-hop contact phase (LC), lateral-hop flight phase (LF), medial hop contact phase (MC), and medial hop flight phase (MF), and the ROM of ankle inversion/eversion, a peak angle of ankle inversion, and Integral EMG (IEMG) of PL and TA compared among 4 phases. Fifteen male subjects with no symptoms of ankle joint problems participated in this research. The ROM of ankle inversion/eversion during the side-hop test was 27 ± 3.8° (mean ± SD), and there was a significant difference in the ROM of ankle inversion/eversion among 4 phases (p < 0.05). The phase in which the widest ROM was presented was the MF. A peak angle of the ankle inversion at MC was significantly greater than at LC and MF (p <0.05). A peak angle of the ankle inversion at LF was significantly greater than at LC and MF. The PL remained contracting with 50-160% of maximal voluntary contraction (MVC). The IEMGs of PL in both the contact phases were significantly greater than in both the flight phases (p < 0.05). In addition, the PL activity at LC was significantly greater than at MC. The TA remained contracting at 50-80% of MVC through the side-hop test. The IEMG of TA at

  12. Sand Impact Tests of a Half-Scale Crew Module Boilerplate Test Article

    NASA Technical Reports Server (NTRS)

    Vassilakos, Gregory J.; Hardy, Robin C.

    2012-01-01

    Although the Orion Multi-Purpose Crew Vehicle (MPCV) is being designed primarily for water landings, a further investigation of launch abort scenarios reveals the possibility of an onshore landing at Kennedy Space Center (KSC). To gather data for correlation against simulations of beach landing impacts, a series of sand impact tests were conducted at NASA Langley Research Center (LaRC). Both vertical drop tests and swing tests with combined vertical and horizontal velocity were performed onto beds of common construction-grade sand using a geometrically scaled crew module boilerplate test article. The tests were simulated using the explicit, nonlinear, transient dynamic finite element code LS-DYNA. The material models for the sand utilized in the simulations were based on tests of sand specimens. Although the LSDYNA models provided reasonable predictions for peak accelerations, they were not always able to track the response through the duration of the impact. Further improvements to the material model used for the sand were identified based on results from the sand specimen tests.

  13. SLS Intertank Test Article, ITA, is attached to crosshead of loa

    NASA Image and Video Library

    2018-04-04

    SLS Intertank Test Article, ITA, is attached to crosshead of load test Annex, Bldg. 4619, and removed from bed of KMAG transporter. ITA is slowly raised from bed of KMAG transporter and KMAG is removed.

  14. Sierra Nevada Corporation's Dream Chaser Test Article Altitude T

    NASA Image and Video Library

    2017-08-30

    Sierra Nevada Corporation’s Dream Chaser completed an important step toward orbital flight with a successful captive carry test at NASA’s Armstrong Flight Research Center in California, located on Edwards Air Force Base. A helicopter successfully carried a Dream Chaser test article, which has the same specifications as a flight-ready spacecraft, to the same altitude and flight conditions of an upcoming free flight test. The Dream Chaser is a lifting-body, winged spacecraft that will fly back to Earth in a manner similar to NASA’s space shuttles. The successful captive carry test clears the way for a free flight test of the spacecraft later this year in which the uncrewed Dream Chaser will be released to glide on its own and land.

  15. Overview of the Acoustic Testing of the European Service Module Structural Test Article (E-STA)

    NASA Technical Reports Server (NTRS)

    Hughes, William; Fogt, Vince; Le Plenier, Cyprien; Duval, Francois; Durand, Jean-Francois; Staab, Lucas D.; Hozman, Aron; Mcnelis, Anne; Bittinger, Samantha; Thirkettle, Anthony; hide

    2017-01-01

    The European Space Agency (ESA) and their prime contractor Airbus Defense Space (ADS) are developing the European Service Module (ESM) for integration and utilization with other modules of NASAs Orion Multi-Purpose Crew Vehicle. As part of this development, ESA, ADS, NASA and the Lockheed Martin Company performed a series of reverberant acoustic tests in April-May 2016 on the ESM Structural Test Article (E-STA), the mechanical mock-up of the ESM designated for mechanical tests. Testing the E-STA under acoustic qualification loads verifies whether it can successfully withstand the medium and high frequency mechanical environment occurring during the vehicles lift-off and atmospheric phases of flight. The testing occurred at the Reverberant Acoustic Test Facility (RATF) at the NASA Glenn Research Centers Plum Brook Station site in Sandusky, OH, USA. This highly successful acoustic test campaign excited the E-STA to acoustic test levels as high as 149.4 dB Overall Sound Pressure Level. This acoustic testing met all the ESA and ADSs test objectives, including establishingverifying the random vibration qualification test levels for numerous hardware components of the ESM, and qualifying the ESMs Solar Array Wing electrical power system. This paper will address the test objectives, the test articles configuration, the test instrumentation and excitation levels, the RATF site and capabilities, the series of acoustic tests performed, and the technical issues faced and overcome to result in a successful acoustic test campaign for the ESM. A discussion of several test results is also included.

  16. Overview of the Acoustic Testing of the European Service Module Structural Test Article (E-STA)

    NASA Technical Reports Server (NTRS)

    Hughes, William; Le Plenier, Cyprien; Duval, Francois; Staab, Lucas; Hozman, Aron; Thirkettle, Anthony; Fogt, Vincent; Durand, Jean-Francois; McNelis, Anne; Bittinger, Samantha; hide

    2017-01-01

    The European Space Agency (ESA) and their prime contractor Airbus Defense Space (ADS) are developing the European Service Module (ESM) for integration and utilization with other modules of NASAs Orion Multi-Purpose Crew Vehicle. As part of this development, ESA, ADS, NASA and the Lockheed Martin Company performed a series of reverberant acoustic tests in April-May 2016 on the ESM Structural Test Article (E-STA), the mechanical mock-up of the ESM designated for mechanical tests. Testing the E-STA under acoustic qualification loads verifies whether it can successfully withstand the medium and high frequency mechanical environment occurring during the vehicles lift-off and atmospheric phases of flight. The testing occurred at the Reverberant Acoustic Test Facility (RATF) at the NASA Glenn Research Centers Plum Brook Station site in Sandusky, OH, USA. This highly successful acoustic test campaign excited the E-STA to acoustic test levels as high as 149.4 dB Overall Sound Pressure Level. This acoustic testing met all the ESA and ADSs test objectives, including establishing/verifying the random vibration qualification test levels for numerous hardware components of the ESM, and qualifying the ESMs Solar Array Wing electrical power system. This paper will address the test objectives, the test articles configuration, the test instrumentation and excitation levels, the RATF site and capabilities, the series of acoustic tests performed, and the technical issues faced and overcome to result in a successful acoustic test campaign for the ESM. A discussion of several test results is also included.

  17. Strength Variation of Parachute Joints

    NASA Technical Reports Server (NTRS)

    Mollmann, Catherine

    2017-01-01

    A parachute joint is defined as a location where a component is sewn or connected to another component. During the design and developmental phase of a parachute system, the joints for each structural component are isolated and tested through a process called seam and joint testing. The objective of seam and joint testing is to determine the degradation on a single component due to interaction with other components; this data is then used when calculating the margin of safety for that component. During the engineering developmental phase of CPAS (Capsule Parachute Assembly System), the parachute system for the NASA Orion Crew Module, testing was completed for every joint of the six subsystems: the four parachutes (main, drogue, pilot, and FBCP [forward bay cover parachute]), the retention release bridle, and the retention panels. The number of joint tests for these subsystems totaled 92, which provides a plethora of data and results for further analysis. In this paper, the data and results of these seam and joint tests are examined to determine the effects, if any, of different operators and sewing machines on the strength of parachute joints. Other variables are also studied to determine their effect on joint strength, such as joint complexity, joint strength magnitude, material type, and material construction. Findings reveal that an optimally-run seam and joint test program could result in an increased understanding of the structure of the parachute; this should lead to a parachute built with optimal components, potentially saving system weight and volume.

  18. Time-Lapse Video of SLS Engine Section Test Article Being Stacked at Michoud

    NASA Image and Video Library

    2017-04-25

    This time-lapse video shows the Space Launch System engine section structural qualification test article being stacked at NASA's Michoud Assembly Facility in New Orleans. The rocket's engine section is the bottom of the core stage and houses the four RS-25 engines. The engine section test article was moved to Michoud's Cell A in Building 110 for vertical stacking with hardware that simulates the rocket's liquid hydrogen tank, which is the fuel tank that joins to the engine section. Once stacked, the entire test article will load onto the barge Pegasus and ship to NASA's Marshall Space Flight Center in Huntsville, Alabama. There, it will be subjected to millions of pounds of force during testing to ensure the hardware can withstand the incredible stresses of launch.

  19. Joint Test Report for Validation of Alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel

    NASA Technical Reports Server (NTRS)

    Lewis, Pattie

    2007-01-01

    Headquarters National Aeronautics and Space Administration (NASA) chartered the NASA Acquisition Pollution Prevention (AP2) Office to coordinate agency activities affecting pollution prevention issues identified during system and component acquisition and sustainment processes. The primary objectives of the AP2 Office are to: (1) Reduce or eliminate the use of hazardous materials or hazardous processes at manufacturing, remanufacturing, and sustainment locations. (2) Avoid duplication of effort in actions required to reduce or eliminate hazardous materials through joint center cooperation and technology sharing. The objective of this project was to qualify candidate alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel applications at NASA facilities. This project compares the surface preparation/depainting performance of the proposed alternatives to existing surface preparation/depainting systems or standards. This Joint Test Report (JTR) contains the results of testing as per the outlines of the Joint Test Protocol (JTP), Joint Test Protocol for Validation of Alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel, and the Field Test Plan (FTP), Field Evaluations Test Plan for Validation of Alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel, for critical requirements and tests necessary to qualify alternatives for coating removal systems. These tests were derived from engineering, performance, and operational impact (supportability) requirements defined by a consensus of government and industry participants. This JTR documents the results of the testing as well as any test modifications made during the execution of the project. This JTR is made available as a reference for future pollution prevention endeavors by other NASA Centers, the Department of Defense and commercial users to minimize duplication of effort. The current coating removal processes

  20. Hot-Fire Test Results of an Oxygen/RP-2 Multi-Element Oxidizer-Rich Staged-Combustion Integrated Test Article

    NASA Technical Reports Server (NTRS)

    Hulka, J. R.; Protz, C. S.; Garcia, C. P.; Casiano, M. J.; Parton, J. A.

    2016-01-01

    As part of the Combustion Stability Tool Development project funded by the Air Force Space and Missile Systems Center, the NASA Marshall Space Flight Center was contracted to assemble and hot-fire test a multi-element integrated test article demonstrating combustion characteristics of an oxygen/hydrocarbon propellant oxidizer-rich staged-combustion engine thrust chamber. Such a test article simulates flow through the main injectors of oxygen/kerosene oxidizer-rich staged combustion engines such as the Russian RD-180 or NK-33 engines, or future U.S.-built engine systems such as the Aerojet-Rocketdyne AR-1 engine or the Hydrocarbon Boost program demonstration engine. For the thrust chamber assembly of the test article, several configurations of new main injectors, using relatively conventional gas-centered swirl coaxial injector elements, were designed and fabricated. The design and fabrication of these main injectors are described in a companion paper at this JANNAF meeting. New ablative combustion chambers were fabricated based on hardware previously used at NASA for testing at similar size and pressure. An existing oxygen/RP-1 oxidizer-rich subscale preburner injector from a previous NASA-funded program, along with existing and new inter-connecting hot gas duct hardware, were used to supply the oxidizer-rich combustion products to the oxidizer circuit of the main injector of the thrust chamber. Results from independent hot-fire tests of the preburner injector in a combustion chamber with a sonic throat are described in companion papers at this JANNAF conference. The resulting integrated test article - which includes the preburner, inter-connecting hot gas duct, main injector, and ablative combustion chamber - was assembled at Test Stand 116 at the East Test Area of the NASA Marshall Space Flight Center. The test article was well instrumented with static and dynamic pressure, temperature, and acceleration sensors to allow the collected data to be used for

  1. Support and Development of Workflow Protocols for High Throughput Single-Lap-Joint Testing-Experimental

    DTIC Science & Technology

    2013-04-01

    preparation, and presence of an overflow fillet for a high strength epoxy and ductile methacylate adhesive. A unique feature of this study was the...of expanding adhesive joint test configurations as part of the GEMS program. 15. SUBJECT TERMS single lap joint, adhesion, aluminum, epoxy ... epoxy and ductile methacylate adhesive. A unique feature of this study was the use of untrained GEMS (Gains in the Education of Mathematics and Sci

  2. 21 CFR 58.107 - Test and control article handling.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Test and control article handling. 58.107 Section 58.107 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL... designed to preclude the possibility of contamination, deterioration, or damage. (c) Proper identification...

  3. Challenges and Opportunities in Design, Fabrication, and Testing of High Temperature Joints in Ceramics and Ceramic Composites

    NASA Technical Reports Server (NTRS)

    Singh, M.; Levine, S. R. (Technical Monitor)

    2001-01-01

    Ceramic joining has been recognized as an enabling technology for successful utilization of advanced ceramics and composite materials. A number of joint design and testing issues have been discussed for ceramic joints in silicon carbide-based ceramics and fiber-reinforced composites. These joints have been fabricated using an affordable, robust ceramic joining technology (ARCJoinT). The microstructure and good high temperature mechanical capability (compressive and flexural strengths) of ceramic joints in silicon carbide-based ceramics and composite materials are reported.

  4. Can joint sound assess soft and hard endpoints of the Lachman test?: A preliminary study.

    PubMed

    Hattori, Koji; Ogawa, Munehiro; Tanaka, Kazunori; Matsuya, Ayako; Uematsu, Kota; Tanaka, Yasuhito

    2016-05-12

    The Lachman test is considered to be a reliable physical examination for anterior cruciate ligament (ACL) injury. Patients with a damaged ACL demonstrate a soft endpoint feeling. However, examiners judge the soft and hard endpoints subjectively. The purpose of our study was to confirm objective performance of the Lachman test using joint auscultation. Human and porcine knee joints were examined. Knee joint sound during the Lachman test (Lachman sound) was analyzed by fast Fourier transformation. As quantitative indices of Lachman sound, the peak sound as the maximum relative amplitude (acoustic pressure) and its frequency were used. The mean Lachman peak sound for healthy volunteer knees was 86.9 ± 12.9 Hz in frequency and -40 ± 2.5 dB in acoustic pressure. The mean Lachman peak sound for intact porcine knees was 84.1 ± 9.4 Hz and -40.5 ± 1.7 dB. Porcine knees with ACL deficiency had a soft endpoint feeling during the Lachman test. The Lachman peak sounds of porcine knees with ACL deficiency were dispersed into four distinct groups, with center frequencies of around 40, 160, 450, and 1600. The Lachman peak sound was capable of assessing soft and hard endpoints of the Lachman test objectively.

  5. Buckling Test Results and Preliminary Test and Analysis Correlation from the 8-Foot-Diameter Orthogrid-Stiffened Cylinder Test Article TA02

    NASA Technical Reports Server (NTRS)

    Hilburger, Mark W.; Waters, W. Allen, Jr.; Haynie, Waddy T.; Thornburgh, Robert P

    2017-01-01

    Results from the testing of cylinder test article SBKF-P2-CYL-TA02 (referred to herein as TA02) are presented. TA02 is an 8-foot-diameter (96-inches), 78.0-inch-long, aluminum-lithium (Al-Li), orthogrid-stiffened cylindrical shell similar to those used in current state-of-the-art launch-vehicle structures and was designed to exhibit global buckling when subjected to combined compression and bending loads. The testing was conducted at the Marshall Space Flight Center (MSFC), February 3-6, 2009, in support of the Shell Buckling Knockdown Factor Project (SBKF). The test was used to verify the performance of a newly constructed buckling test facility at MSFC and to verify the test article design and analysis approach used by the SBKF researchers.

  6. Development of Bonded Joint Technology for a Rigidizable-Inflatable Deployable Truss

    NASA Technical Reports Server (NTRS)

    Smeltzer, Stanley S., III

    2006-01-01

    Microwave and Synthetic Aperture Radar antenna systems have been developed as instrument systems using truss structures as their primary support and deployment mechanism for over a decade. NASA Langley Research Center has been investigating fabrication, modular assembly, and deployment methods of lightweight rigidizable/inflatable linear truss structures during that time for large spacecraft systems. The primary goal of the research at Langley Research Center is to advance these existing state-of-the-art joining and deployment concepts to achieve prototype system performance in a relevant space environment. During 2005, the development, fabrication, and testing of a 6.7 meter multi-bay, deployable linear truss was conducted at Langley Research Center to demonstrate functional and precision metrics of a rigidizable/inflatable truss structure. The present paper is intended to summarize aspects of bonded joint technology developed for the 6.7 meter deployable linear truss structure while providing a brief overview of the entire truss fabrication, assembly, and deployment methodology. A description of the basic joint design, surface preparation investigations, and experimental joint testing of component joint test articles will be described. Specifically, the performance of two room temperature adhesives were investigated to obtain qualitative data related to tube folding testing and quantitative data related to tensile shear strength testing. It was determined from the testing that a polyurethane-based adhesive best met the rigidizable/inflatable truss project requirements.

  7. Satellite Power Systems (SPS). LSST systems and integration task for SPS flight test article

    NASA Technical Reports Server (NTRS)

    Greenberg, H. S.

    1981-01-01

    This research activity emphasizes the systems definition and resulting structural requirements for the primary structure of two potential SPS large space structure test articles. These test articles represent potential steps in the SPS research and technology development.

  8. Orion Ground Test Article Water Impact Tests: Photogrammetric Evaluation of Impact Conditions

    NASA Technical Reports Server (NTRS)

    Vassilakos, Gregory J.; Mark, Stephen D.

    2018-01-01

    The Ground Test Article (GTA) is an early production version of the Orion Crew Module (CM). The structural design of the Orion CM is being developed based on LS-DYNA water landing simulations. As part of the process of confirming the accuracy of LS-DYNA water landing simulations, the GTA water impact test series was conducted at NASA Langley Research Center (LaRC) to gather data for comparison with simulations. The simulation of the GTA water impact tests requires the accurate determination of the impact conditions. To accomplish this, the GTA was outfitted with an array of photogrammetry targets. The photogrammetry system utilizes images from two cameras with a specialized tracking software to determine time histories for the 3-D coordinates of each target. The impact conditions can then be determined from the target location data.

  9. European Service Module-Structural Test Article Load onto Transp

    NASA Image and Video Library

    2017-06-21

    The Orion service module structural test article for Exploration Mission-1 (EM-1), built by the European Space Agency, is prepared for shipment to Lockheed Martin's Denver facility to undergo testing. Inside the Neil Armstrong Operations and Checkout Building high bay at NASA's Kennedy Space Center in Florida, workers secure the protective covering around the module and a crane lifts the module, secured on stand, for the move to the transport truck. The Orion spacecraft will launch atop the agency's Space Launch System rocket on EM-1 in 2019.

  10. Hybrid Wing Body Multi-Bay Test Article Analysis and Assembly Final Report

    NASA Technical Reports Server (NTRS)

    Velicki, Alexander; Hoffman, Krishna; Linton, Kim A.; Baraja, Jaime; Wu, Hsi-Yung T.; Thrash, Patrick

    2017-01-01

    This report summarizes work performed by The Boeing Company, through its Boeing Research & Technology organization located in Huntington Beach, California, under the Environmentally Responsible Aviation (ERA) project. The report documents work performed to structurally analyze and assemble a large-scale Multi-bay Box (MBB) Test Article capable of withstanding bending and internal pressure loadings representative of a Hybrid Wing Body (HWB) aircraft. The work included fabrication of tooling elements for use in the fabrication and assembly of the test article.

  11. Longitudinally Jointed Edge-Wise Compression HoneyComb Composite Sandwich Coupon Testing And Fe Analysis: Three Methods of Strain Measurement, And Comparison

    NASA Technical Reports Server (NTRS)

    Farrokh, Babak; Rahim, Nur Aida Abul; Segal, Ken; Fan, Terry; Jones, Justin; Hodges, Ken; Mashni, Noah; Garg, Naman; Sang, Alex

    2013-01-01

    Three distinct strain measurement methods (i.e., foil resistance strain gages, fiber optic strain sensors, and a three-dimensional digital image photogrammetry that gives full field strain and displacement measurements) were implemented to measure strains on the back and front surfaces of a longitudinally jointed curved test article subjected to edge-wise compression testing, at NASA Goddard Space Flight Center, according to ASTM C364. The pre-test finite element analysis (FEA) was conducted to assess ultimate failure load and predict strain distribution pattern throughout the test coupon. The predicted strain pattern contours were then utilized as guidelines for installing the strain measurement instrumentations. The foil resistance strain gages and fiber optic strain sensors were bonded on the specimen at locations with nearly the same analytically predicted strain values, and as close as possible to each other, so that, comparisons between the measured strains by strain gages and fiber optic sensors, as well as the three-dimensional digital image photogrammetric system are relevant. The test article was loaded to failure (at 167 kN), at the compressive strain value of 10,000 micro epsilon. As a part of this study, the validity of the measured strains by fiber optic sensors is examined against the foil resistance strain gages and the three-dimensional digital image photogrammetric data, and comprehensive comparisons are made with FEA predictions.

  12. Determination of consistent patterns of range of motion in the ankle joint with a computed tomography stress-test.

    PubMed

    Tuijthof, Gabriëlle Josephine Maria; Zengerink, Maartje; Beimers, Lijkele; Jonges, Remmet; Maas, Mario; van Dijk, Cornelis Niek; Blankevoort, Leendert

    2009-07-01

    Measuring the range of motion of the ankle joint can assist in accurate diagnosis of ankle laxity. A computed tomography-based stress-test (3D CT stress-test) was used that determines the three-dimensional position and orientation of tibial, calcaneal and talar bones. The goal was to establish a quantitative database of the normal ranges of motion of the talocrural and subtalar joints. A clinical case on suspected subtalar instability demonstrated the relevance the proposed method. The range of motion was measured for the ankle joints in vivo for 20 subjects using the 3D CT stress-test. Motion of the tibia and calcaneus relative to the talus for eight extreme foot positions were described by helical parameters. High consistency for finite helical axis orientation (n) and rotation (theta) was shown for: talocrural extreme dorsiflexion to extreme plantarflexion (root mean square direction deviation (eta) 5.3 degrees and theta: SD 11.0 degrees), talorucral and subtalar extreme combined eversion-dorsiflexion to combined inversion-plantarflexion (eta: 6.7 degrees , theta: SD 9.0 degrees and eta:6.3 degrees , theta: SD 5.1 degrees), and subtalar extreme inversion to extreme eversion (eta: 6.4 degrees, theta: SD 5.9 degrees). Nearly all dorsi--and plantarflexion occurs in the talocrural joint (theta: mean 63.3 degrees (SD 11 degrees)). The inversion and internal rotation components for extreme eversion to inversion were approximately three times larger for the subtalar joint (theta: mean 22.9 degrees and 29.1 degrees) than for the talocrural joint (theta: mean 8.8 degrees and 10.7 degrees). Comparison of the ranges of motion of the pathologic ankle joint with the healthy subjects showed an increased inversion and axial rotation in the talocrural joint instead of in the suspected subtalar joint. The proposed diagnostic technique and the acquired database of helical parameters of ankle joint ranges of motion are suitable to apply in clinical cases.

  13. Impact extractive fracture of jointed steel plates of a bolted joint

    NASA Astrophysics Data System (ADS)

    Daimaruya, M.; Fujiki, H.; Ambarita, H.

    2012-08-01

    This study is concerned with the development of a fracture criterion for the impact fracture of jointed steel plates of a bolted joint used in a car body. For the accurate prediction of crash characteristics of car bodies by computer-aided engineering (CAE), it is also necessary to examine the behavior and fracture of jointed steel plates subjected to impact loads. Although the actual impact fracture of jointed steel plates of a bolted joint used in cars is complicated, for simplifying the problem it might be classified into the shear fracture and the extractive fracture of jointed steel plates. Attention is given to the extractive fracture of jointed steel plates in this study. The extractive behavior and fracture of three kinds of steel plates used for cars are examined in experiments and numerical simulations. The impact extraction test of steel plates jointed by a bolt is performed using the one-bar method, together with the static test. In order to understand the mechanism of extractive fracture process of jointed steel plates, numerical simulations by a FEM code LS-DYNA are also carried out. The obtained results suggest that a stress-based fracture criterion may be developed for the impact extractive fracture of jointed steel plates of a bolted joint used in a car body.

  14. Adhesive properties and adhesive joints strength of graphite/epoxy composites

    NASA Astrophysics Data System (ADS)

    Rudawska, Anna; Stančeková, Dana; Cubonova, Nadezda; Vitenko, Tetiana; Müller, Miroslav; Valášek, Petr

    2017-05-01

    The article presents the results of experimental research of the adhesive joints strength of graphite/epoxy composites and the results of the surface free energy of the composite surfaces. Two types of graphite/epoxy composites with different thickness were tested which are used to aircraft structure. The single-lap adhesive joints of epoxy composites were considered. Adhesive properties were described by surface free energy. Owens-Wendt method was used to determine surface free energy. The epoxy two-component adhesive was used to preparing the adhesive joints. Zwick/Roell 100 strength device were used to determination the shear strength of adhesive joints of epoxy composites. The strength test results showed that the highest value was obtained for adhesive joints of graphite-epoxy composite of smaller material thickness (0.48 mm). Statistical analysis of the results obtained, the study showed statistically significant differences between the values of the strength of the confidence level of 0.95. The statistical analysis of the results also showed that there are no statistical significant differences in average values of surface free energy (0.95 confidence level). It was noted that in each of the results the dispersion component of surface free energy was much greater than polar component of surface free energy.

  15. How Well do the Military Services Perform Jointly in Combat? DoD’s Joint Test-and-Evaluation Program Provides Few Credible Answers.

    DTIC Science & Technology

    1984-02-22

    of the test conditions were unrealistic. For example, four better-than-average pilots flew all the test missions in mostly excellent weather, in one...that aircraft pilots need to respond to a request for close air support is likely to influence combat effectiveness. Earl- ier joint testing had made...in the JTF reports. For example, the IIR Maverick report contains the conclusion that, in general, the pilots detected targets easily, but the test

  16. Comparisons of false negative rates from a trend test alone and from a trend test jointly with a control-high groups pairwise test in the determination of the carcinogenicity of new drugs.

    PubMed

    Lin, Karl K; Rahman, Mohammad A

    2018-05-21

    Interest has been expressed in using a joint test procedure that requires that the results of both a trend test and a pairwise comparison test between the control and the high groups be statistically significant simultaneously at the levels of significance recommended in the FDA 2001 draft guidance for industry document for the separate tests in order for the drug effect on the development of an individual tumor type to be considered as statistically significant. Results of our simulation studies show that there is a serious consequence of large inflations of the false negative rate through large decreases of false positive rate in the use of the above joint test procedure in the final interpretation of the carcinogenicity potential of a new drug if the levels of significance recommended for separate tests are used. The inflation can be as high as 204.5% of the false negative rate when the trend test alone is required to test if the effect is statistically significant. To correct the problem, new sets of levels of significance have also been developed for those who want to use the joint test in reviews of carcinogenicity studies.

  17. The Effect of Joint Mobilization on Dynamic Postural Control in Patients With Chronic Ankle Instability: A Critically Appraised Topic.

    PubMed

    Kosik, Kyle B; Gribble, Phillip A

    2018-01-01

    Clinical Scenario: Dorsiflexion range of motion is an important factor in the performance of the Star Excursion Balance Test (SEBT). While patients with chronic ankle instability (CAI) commonly experience decreased reach distances on the SEBT, ankle joint mobilization has been suggested to be an effective therapeutic intervention for targeting dorsiflexion range of motion. What is the evidence to support ankle joint mobilization for improving performance on the SEBT in patients with CAI? Summary of Key Findings: The literature was searched for articles examining the effects of ankle joint mobilization on scores of the SEBT. A total of 3 peer-reviewed articles were retrieved, 2 prospective individual cohort studies and 1 randomized controlled trial. Only 2 articles demonstrated favorable results following 6 sessions of ankle joint mobilization. Clinical Bottom Line: Despite the mixed results, the majority of the available evidence suggests that ankle joint mobilization improves dynamic postural control. Strength of Recommendation: In accordance with the Centre of Evidence Based Medicine, the inconsistent results and the limited high-quality studies indicate that there is level C evidence to support the use of ankle joint mobilization to improve performance on the SEBT in patients with CAI.

  18. Test Review: Prueba de Lectura y Lenguaje Escrito.

    ERIC Educational Resources Information Center

    Crawford, Alan N.

    1984-01-01

    Describes the Prueba de Lectura y Lenguaje Escrito (PPLE--roughly translatable as the "Test of Early Language Development") that may meet the need for standardized and diagnostic tests of reading and written composition in Spanish. (HOD)

  19. Human knee joint sound during the Lachman test: Comparison between healthy and anterior cruciate ligament-deficient knees.

    PubMed

    Tanaka, Kazunori; Ogawa, Munehiro; Inagaki, Yusuke; Tanaka, Yasuhito; Nishikawa, Hitoshi; Hattori, Koji

    2017-05-01

    The Lachman test is clinically considered to be a reliable physical examination for anterior cruciate ligament (ACL) deficiency. However, the test involves subjective judgement of differences in tibial translation and endpoint quality. An auscultation system has been developed to allow assessment of the Lachman test. The knee joint sound during the Lachman test was analyzed using fast Fourier transformation. The purpose of the present study was to quantitatively evaluate knee joint sounds in healthy and ACL-deficient human knees. Sixty healthy volunteers and 24 patients with ACL injury were examined. The Lachman test with joint auscultation was evaluated using a microphone. Knee joint sound during the Lachman test (Lachman sound) was analyzed by fast Fourier transformation. As quantitative indices of the Lachman sound, the peak sound (Lachman peak sound) as the maximum relative amplitude (acoustic pressure) and its frequency were used. In healthy volunteers, the mean Lachman peak sound of intact knees was 100.6 Hz in frequency and -45 dB in acoustic pressure. Moreover, a sex difference was found in the frequency of the Lachman peak sound. In patients with ACL injury, the frequency of the Lachman peak sound of the ACL-deficient knees was widely dispersed. In the ACL-deficient knees, the mean Lachman peak sound was 306.8 Hz in frequency and -63.1 dB in acoustic pressure. If the reference range was set at the frequency of the healthy volunteer Lachman peak sound, the sensitivity, specificity, positive predictive value, and negative predictive value were 83.3%, 95.6%, 95.2%, and 85.2%, respectively. Knee joint auscultation during the Lachman test was capable of judging ACL deficiency on the basis of objective data. In particular, the frequency of the Lachman peak sound was able to assess ACL condition. Copyright © 2016 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

  20. Test-retest reliability of sudden ankle inversion measurements in subjects with healthy ankle joints.

    PubMed

    Eechaute, Christophe; Vaes, Peter; Duquet, William; Van Gheluwe, Bart

    2007-01-01

    Sudden ankle inversion tests have been used to investigate whether the onset of peroneal muscle activity is delayed in patients with chronically unstable ankle joints. Before interpreting test results of latency times in patients with chronic ankle instability and healthy subjects, the reliability of these measures must be first demonstrated. To investigate the test-retest reliability of variables measured during a sudden ankle inversion movement in standing subjects with healthy ankle joints. Validation study. Research laboratory. 15 subjects with healthy ankle joints (30 ankles). Subjects stood on an ankle inversion platform with both feet tightly fixed to independently moveable trapdoors. An unexpected sudden ankle inversion of 50 degrees was imposed. We measured latency and motor response times and electromechanical delay of the peroneus longus muscle, along with the time and angular position of the first and second decelerating moments, the mean and maximum inversion speed, and the total inversion time. Correlation coefficients and standard error of measurements were calculated. Intraclass correlation coefficients ranged from 0.17 for the electromechanical delay of the peroneus longus muscle (standard error of measurement = 2.7 milliseconds) to 0.89 for the maximum inversion speed (standard error of measurement = 34.8 milliseconds). The reliability of the latency and motor response times of the peroneus longus muscle, the time of the first and second decelerating moments, and the mean and maximum inversion speed was acceptable in subjects with healthy ankle joints and supports the investigation of the reliability of these measures in subjects with chronic ankle instability. The lower reliability of the electromechanical delay of the peroneus longus muscle and the angular positions of both decelerating moments calls the use of these variables into question.

  1. LFC leading edge glove flight: Aircraft modification design, test article development and systems integration

    NASA Technical Reports Server (NTRS)

    Etchberger, F. R.

    1983-01-01

    Reduction of skin friction drag by suction of boundary layer air to maintain laminar flow has been known since Prandtl's published work in 1904. The dramatic increases in fuel costs and the potential for periods of limited fuel availability provided the impetus to explore technologies to reduce transport aircraft fuel consumption. NASA sponsored the Aircraft Energy Efficiency (ACEE) program in 1976 to develop technologies to improve fuel efficiency. This report documents the Lockheed-Georgia Company accomplishments in designing and fabricating a leading-edge flight test article incorporating boundary layer suction slots to be flown by NASA on their modified JetStar aircraft. Lockheed-Georgia Company performed as the integration contractor to design the JetStar aircraft modification to accept both a Lockheed and a McDonnell Douglas flight test article. McDonnell Douglas uses a porous skin concept. The report describes aerodynamic analyses, fabrication techniques, JetStar modifications, instrumentation requirements, and structural analyses and testing for the Lockheed test article. NASA will flight test the two LFC leading-edge test articles in a simulated commercial environment over a 6 to 8 month period in 1984. The objective of the flight test program is to evaluate the effectiveness of LFC leading-edge systems in reducing skin friction drag and consequently improving fuel efficiency.

  2. Metacarpophalangeal joint arthroscopy: indications revisited.

    PubMed

    Choi, Alexander K Y; Chow, Esther C S; Ho, P C; Chow, Y Y

    2011-08-01

    Arthroscopic surgery has become the gold standard for the diagnosis and treatment of major joint disorders. With advancement in arthroscopic technique, arthroscopy has become feasible in most human joints, even those as small as the finger joints. The metacarpophalangeal joint (MCPJ) can become spacious with simple traction, the intra-articular anatomy is simple, and its major structures can be easily visualized and identified. However, MCPJ arthroscopy has never been popular. This article describes our experience with MCPJ arthroscopy and seeks to establish its role in clinical practice. Copyright © 2011 Elsevier Inc. All rights reserved.

  3. Predicting the Drop Performance of Solder Joints by Evaluating the Elastic Strain Energy from High-Speed Ball Pull Tests

    NASA Astrophysics Data System (ADS)

    You, Taehoon; Kim, Yunsung; Kim, Jina; Lee, Jaehong; Jung, Byungwook; Moon, Jungtak; Choe, Heeman

    2009-03-01

    Despite being expensive and time consuming, board-level drop testing has been widely used to assess the drop or impact resistance of the solder joints in handheld microelectronic devices, such as cellphones and personal digital assistants (PDAs). In this study, a new test method, which is much simpler and quicker, is proposed. The method involves evaluating the elastic strain energy and relating it to the impact resistance of the solder joint by considering the Young’s modulus of the bulk solder and the fracture stress of the solder joint during a ball pull test at high strain rates. The results show that solder joints can be ranked in order of descending elastic strain energy as follows: Sn-37Pb, Sn-1Ag-0.5Cu, Sn-3Ag-0.5Cu, and Sn-4Ag-0.5Cu. This order is consistent with the actual drop performances of the samples.

  4. New Equipment for Testing the Fatigue Strength of Riveted and Welded Joints

    NASA Technical Reports Server (NTRS)

    Muller, W

    1940-01-01

    The mechanical and electrical construction of a new experimental instrument for fatigue testing riveted and welded joints is described. This experimental device has the advantage of being able to stress, even with comparatively low magnetic exciter force, structural components in alternate bending by resonance vibrations up to incipient fatigue failure.

  5. SLS Engine Section Test Article Moves From NASA Barge Pegasus To Test Stand at NASA’s Marshall Space Flight Center

    NASA Image and Video Library

    2017-05-18

    The NASA barge Pegasus made its first trip to NASA’s Marshall Space Flight Center in Huntsville, Alabama on May 15. It arrived carrying the first piece of Space Launch System hardware built at NASA's Michoud Assembly Facility in New Orleans. The barge left Michoud on April 28 with the core stage engine section test article, traveling 1,240 miles by river to Marshall. The rocket's engine section is the bottom of the core stage and houses the four RS-25 engines. The engine section test article was moved from the barge to Marshall’s Building 4619 where it will be tested. The bottom part of the test article is structurally the same as the engine section that will be flown as part of the SLS core stage. The shiny metal top part simulates the rocket's liquid hydrogen tank, which is the fuel tank that joins to the engine section. The test article will endure tests that pull, push, and bend it, subjecting it to millions of pounds of force. This ensures the structure can withstand the incredible stresses produced by the 8.8 million pounds of thrust during launch and ascent.

  6. Gen. Joseph F. Dunford, Jr. > Joint Chiefs of Staff > Article View

    Science.gov Websites

    Facebook on Flickr Joint Chiefs Army Chief of Staff Marine Corps Commandant Chief of Naval Operations Air Force Chief of Staff Chief of National Guard Bureau Biographies Directorates Directorates of Management Chiefs of Staff, the nation's highest-ranking military officer, and the principal military advisor to the

  7. Shear fracture of jointed steel plates of bolted joints under impact load

    NASA Astrophysics Data System (ADS)

    Daimaruya, M.; Fujiki, H.; Ambarita, H.; Kobayashi, H.; Shin, H.-S.

    2013-07-01

    The present study is concerned with the development of a fracture criterion for the impact fracture of jointed steel plates of bolted joints used in a car body, which contributes to crash simulations by CAE. We focus our attention on the shear fracture of the jointed steel plates of lap-bolted joints in the suspension of a car under impact load. Members of lap-bolted joints are modelled as a pair of steel plates connected by a bolt. One of the plates is a specimen subjected to plastic deformation and fracture and the other is a jig subjected to elastic deformation only. Three kinds of steel plate specimens are examined, i.e., a common steel plate with a tensile strength of 270 MPa and high tensile strength steel plates of 440 and 590 MPa used for cars. The impact shear test was performed using the split Hopkinson bar technique for tension impact, together with the static test using a universal testing machine INSTRON 5586. The behaviour of the shear stress and deformation up to rupture taking place in the joint was discussed. The obtained results suggest that a stress-based fracture criterion may be developed for the impact fracture of jointed steel plates of a lap-bolted joint.

  8. Dissimilar metals joint evaluation

    NASA Technical Reports Server (NTRS)

    Wakefield, M. E.; Apodaca, L. E.

    1974-01-01

    Dissimilar metals tubular joints between 2219-T851 aluminum alloy and 304L stainless steel were fabricated and tested to evaluate bonding processes. Joints were fabricated by four processes: (1) inertia (friction) weldings, where the metals are spun and forced together to create the weld; (2) explosive welding, where the metals are impacted together at high velocity; (3) co-extrusion, where the metals are extruded in contact at high temperature to promote diffusion; and (4) swaging, where residual stresses in the metals after a stretching operation maintain forced contact in mutual shear areas. Fifteen joints of each type were prepared and evaluated in a 6.35 cm (2.50 in.) O.D. size, with 0.32 cm (0.13 in.) wall thickness, and 7.6 cm (3.0 in) total length. The joints were tested to evaluate their ability to withstand pressure cycle, thermal cycle, galvanic corrosion and burst tests. Leakage tests and other non-destructive test techniques were used to evaluate the behavior of the joints, and the microstructure of the bond areas was analyzed.

  9. Life Assessment for Cr-Mo Steel Dissimilar Joints by Various Filler Metals Using Accelerated Creep Testing

    NASA Astrophysics Data System (ADS)

    Petchsang, S.; Phung-on, I.; Poopat, B.

    2016-12-01

    Accelerated creep rupture tests were performed on T22/T91 dissimilar metal joints to determine the fracture location and rupture time of different weldments. Four configurations of deposited filler metal were tested using gas tungsten arc welding to estimate the service life for Cr-Mo steel dissimilar joints at elevated temperatures in power plants. Results indicated that failure in all configurations occurred in the tempered original microstructure and tempered austenite transformation products (martensite or bainite structure) as type IV cracking at the intercritical area of the heat-affected zone (ICHAZ) for both T22 and T91 sides rather than as a consequence of the different filler metals. Creep damage occurred with the formation of precipitations and microvoids. The correlation between applied stress and the Larson-Miller parameter (PLM) was determined to predict the service life of each material configuration. Calculated time-to-failure based on the PLM and test results for both temperature and applied stress parameters gave a reasonable fit. The dissimilar joints exhibited lower creep rupture compared to the base material indicating creep degradation of the weldment.

  10. Solid Rocket Booster Hydraulic Pump Port Cap Joint Load Testing

    NASA Technical Reports Server (NTRS)

    Gamwell, W. R.; Murphy, N. C.

    2004-01-01

    The solid rocket booster uses hydraulic pumps fabricated from cast C355 aluminum alloy, with 17-4 PH stainless steel pump port caps. Corrosion-resistant steel, MS51830 CA204L self-locking screw thread inserts are installed into C355 pump housings, with A286 stainless steel fasteners installed into the insert to secure the pump port cap to the housing. In the past, pump port cap fasteners were installed to a torque of 33 Nm (300 in-lb). However, the structural analyses used a significantly higher nut factor than indicated during tests conducted by Boeing Space Systems. When the torque values were reassessed using Boeing's nut factor, the fastener preload had a factor of safety of less than 1, with potential for overloading the joint. This paper describes how behavior was determined for a preloaded joint with a steel bolt threaded into steel inserts in aluminum parts. Finite element models were compared with test results. For all initial bolt preloads, bolt loads increased as external applied loads increased. For higher initial bolt preloads, less load was transferred into the bolt, due to external applied loading. Lower torque limits were established for pump port cap fasteners and additional limits were placed on insert axial deformation under operating conditions after seating the insert with an initial preload.

  11. Summary of LSST systems analysis and integration task for SPS flight test articles

    NASA Astrophysics Data System (ADS)

    Greenberg, H. S.

    1981-02-01

    The structural and equipment requirements for two solar power satellite (SPS) test articles are defined. The first SPS concept uses a hexagonal frame structure to stabilize the array of primary tension cables configured to support a Mills Cross antenna containing 17,925 subarrays composed of dipole radiating elements and solid state power amplifier modules. The second test article consists of a microwave antenna and its power source, a 20 by 200 m array of solar cell blankets, both of which are supported by the solar blanket array support structure. The test article structure, a ladder, is comprised of two longitudinal beams (215 m long) spaced 10 m apart and interconnected by six lateral beams. The system control module structure and bridge fitting provide bending and torsional stiffness, and supplement the in plane Vierendeel structure behavior. Mission descriptions, construction, and structure interfaces are addressed.

  12. Ankle joint pressure changes in high tibial and distal femoral osteotomies: a cadaver study.

    PubMed

    Krause, F; Barandun, A; Klammer, G; Zderic, I; Gueorguiev, B; Schmid, T

    2017-01-01

    To assess the effect of high tibial and distal femoral osteotomies (HTO and DFO) on the pressure characteristics of the ankle joint. Varus and valgus malalignment of the knee was simulated in human cadaver full-length legs. Testing included four measurements: baseline malalignment, 5° and 10° re-aligning osteotomy, and control baseline malalignment. For HTO, testing was rerun with the subtalar joint fixed. In order to represent half body weight, a 300 N force was applied onto the femoral head. Intra-articular sensors captured ankle pressure. In the absence of restriction of subtalar movement, insignificant migration of the centre of force and changes of maximal pressure were seen at the ankle joint. With restricted subtalar motion, more significant lateralisation of the centre of force were seen with the subtalar joint in varus than in valgus position. Changes in maximum pressure were again not significant. The re-alignment of coronal plane knee deformities by HTO and DFO altered ankle pressure characteristics. When the subtalar joint was fixed in the varus position, migration of centre of force after HTO was more significant than when the subtalar joint was fixed in valgus. Cite this article: Bone Joint J 2017;99-B:59-65. ©2017 The British Editorial Society of Bone & Joint Surgery.

  13. Biaxially textured articles formed by powder metallurgy

    DOEpatents

    Goyal, Amit; Williams, Robert K.

    2001-01-01

    A biaxially textured alloy article comprises Ni powder and at least one powder selected from the group consisting of Cr, W, V, Mo, Cu, Al, Ce, YSZ, Y, Rare Earths, (RE), MgO, CeO.sub.2, and Y.sub.2 O.sub.3 ; compacted and heat treated, then rapidly recrystallized to produce a biaxial texture on the article. In some embodiments the alloy article further comprises electromagnetic or electro-optical devices and possesses superconducting properties.

  14. Using Response Surface Methods to Correlate the Modal Test of an Inflatable Test Article

    NASA Technical Reports Server (NTRS)

    Gupta, Anju

    2013-01-01

    This paper presents a practical application of response surface methods (RSM) to correlate a finite element model of a structural modal test. The test article is a quasi-cylindrical inflatable structure which primarily consists of a fabric weave, with an internal bladder and metallic bulkheads on either end. To mitigate model size, the fabric weave was simplified by representing it with shell elements. The task at hand is to represent the material behavior of the weave. The success of the model correlation is measured by comparing the four major modal frequencies of the analysis model to the four major modal frequencies of the test article. Given that only individual strap material properties were provided and material properties of the overall weave were not available, defining the material properties of the finite element model became very complex. First it was necessary to determine which material properties (modulus of elasticity in the hoop and longitudinal directions, shear modulus, Poisson's ratio, etc.) affected the modal frequencies. Then a Latin Hypercube of the parameter space was created to form an efficiently distributed finite case set. Each case was then analyzed with the results input into RSM. In the resulting response surface it was possible to see how each material parameter affected the modal frequencies of the analysis model. If the modal frequencies of the analysis model and its corresponding parameters match the test with acceptable accuracy, it can be said that the model correlation is successful.

  15. Structural tests and development of a laminar flow control wing surface composite chordwise joint

    NASA Technical Reports Server (NTRS)

    Lineberger, L. B.

    1984-01-01

    The dramatic increases in fuel costs and the potential for periods of limited fuel availability provided the impetus to explore technologies to reduce transport aircraft fuel consumption. NASA sponsored the Aircraft Energy Efficiency (ACEE) program beginning in 1976 to develop technologies to improve fuel efficiency. The Lockheed-Georgia Company accomplished under NAS1-16235 Laminar-Flow-Control (LFC) Wing Panel Structural Design and Development (WSSD); design, manufacturing, and testing activities. An in-depth preliminary design of the baseline 1993 LFC wing was accomplished. A surface panel using the Lockheed graphite/epoxy integrated LFC wing box structural concept was designed. The concept was shown by analysis to be structurally efficient and cost effective. Critical details of the surface and surface joint was demonstrated by fabricating and testing complex, concept selection specimens. The Lockheed-Georgia Company accomplishments, Development of LFC Wind Surface Composite Structures (WSCS), are documented. Tests were conducted on two CV2 panels to verify the static tension and fatigue strength of LFC wing surface chordwise joints.

  16. Joint Ordnance Test Procedure (JOTP)-001 Allied Ammunition Safety and Suitability for Service Assessment Testing Publication - Guidance

    DTIC Science & Technology

    2013-01-08

    hazard due to enemy attack or accident (e.g. Insensitive Munitions (IM) and Electromagnetic Environmental Effects (E3)) and the explosive materials...of mitigating potential explosive remnants of war hazards , particularly from unexploded ordnance , should be conducted. 6.5 Munition Software System...TYPE Final 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE Joint Ordnance Test Procedure (JOTP)-001 Allied Ammunition Safety and

  17. The comparison of measurement between ultrasound and computed tomography for abnormal degenerative facet joints: A STROBE-compliant article.

    PubMed

    Shi, Wen; Tian, Dan; Liu, Da; Yin, Jing; Huang, Ying

    2017-08-01

    Besides the study on examining facet joints of lumbar spine by ultrasound in normal population, there has not been any related report about examining normal facet joints of lumbar spine by ultrasound so far. This study was aimed to explore the feasibility of ultrasound assessment of lumber spine facet joints by comparing ultrasound measure values of normal and degenerative lumber spine facet joints, and by comparing measure values of ultrasound and computed tomography (CT) of degenerative lumber spine facet joints.This study included 15 patients who had chronic low back pain because of degenerative change in lumbar vertebrae, and 19 volunteers who did not have low back pain or pain in the lower limb. The ultrasound measure values (height [H] and width [W]) of normal and degenerative lumber spine facet joints were compared. And the differentiation between measure values (H and W) of ultrasound and CT of degenerative lumber spine facet joints was also analyzed.The ultrasound clearly showed abnormal facet joints lesion, which was characterized by hyperostosis on the edge of joints, bone destruction under joints, and thinner or thicker articular cartilage. There were significant differences between the ultrasound measure values of the normal (H: 1.26 ± 0.03 cm, W: 0.18 ± 0.01 cm) and abnormal facet joints (H: 1.43 ± 0.05 cm, W: 0.15 ± 0.02 cm) (all P < .05). However, there were no significant differences between the measure values of the ultrasound (H: 1.43 ± 0.17 cm, W: 0.15 ± 0.03 cm) and CT (H: 1.42 ± 0.16, W: 0.14 ± 0.03) of the degenerative lumber spine facet joints (all P > .05).Ultrasound can clearly show the structure of facet joints of lumbar spine. It is precise and feasible to assess facet joints of lumbar spine by ultrasound. This study has important significance for the diagnosis of lumbar facet joint degeneration.

  18. Design of 8-ft-Diameter Barrel Test Article Attachment Rings for Shell Buckling Knockdown Factor Project

    NASA Technical Reports Server (NTRS)

    Lovejoy, Andrew E.; Hilburger, Mark W.

    2010-01-01

    The Shell Buckling Knockdown Factor (SBKF) project includes the testing of sub-scale cylinders to validate new shell buckling knockdown factors for use in the design of the Ares-I and Ares-V launch vehicles. Test article cylinders represent various barrel segments of the Ares-I and Ares-V vehicles, and also include checkout test articles. Testing will be conducted at Marshall Space Flight Center (MSFC) for test articles having an eight-foot diameter outer mold line (OML) and having lengths that range from three to ten feet long. Both ends of the test articles will be connected to the test apparatus using attachment rings. Three multiple-piece and one single-piece design for the attachment rings were developed and analyzed. The single-piece design was chosen and will be fabricated from either steel or aluminum (Al) depending on the required safety factors (SF) for test hardware. This report summarizes the design and analysis of these attachment ring concepts.

  19. An activated energy approach for accelerated testing of the deformation of UHMWPE in artificial joints.

    PubMed

    Galetz, Mathias Christian; Glatzel, Uwe

    2010-05-01

    The deformation behavior of ultrahigh molecular polyethylene (UHMWPE) is studied in the temperature range of 23-80 degrees C. Samples are examined in quasi-static compression, tensile and creep tests to determine the accelerated deformation of UHMWPE at elevated temperatures. The deformation mechanisms under compression load can be described by one strain rate and temperature dependent Eyring process. The activation energy and volume of that process do not change between 23 degrees C and 50 degrees C. This suggests that the deformation mechanism under compression remains stable within this temperature range. Tribological tests are conducted to transfer this activated energy approach to the deformation behavior under loading typical for artificial knee joints. While this approach does not cover the wear mechanisms close to the surface, testing at higher temperatures is shown to have a significant potential to reduce the testing time for lifetime predictions in terms of the macroscopic creep and deformation behavior of artificial joints. Copyright 2010. Published by Elsevier Ltd.

  20. Aging changes in the bones - muscles - joints

    MedlinePlus

    ... ency/article/004015.htm Aging changes in the bones - muscles - joints To use the sharing features on ... to the body. Joints are the areas where bones come together. They allow the skeleton to be ...

  1. Joint Test Protocol for Validation of Alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel

    NASA Technical Reports Server (NTRS)

    Lewis, Pattie

    2005-01-01

    Headquarters National Aeronautics and Space Administration (NASA) chartered the Acquisition Pollution Prevention (AP2) Office to coordinate agency activities affecting pollution prevention issues identified during system and component acquisition and sustainment processes. The primary objectives of the AP2 Office are to: (1) Reduce or eliminate the use of hazardous materials (HazMats) or hazardous processes at manufacturing, remanufacturing, and sustainment locations. (2) A void duplication of effort in actions required to reduce or eliminate HazMats through joint center cooperation and technology sharing. This project will identify, evaluate and approve alternative surface preparation technologies for use at NASA and Air Force Space Command (AFSPC) installations. Materials and processes will be evaluated with the goal of selecting those processes that will improve corrosion protection at critical systems, facilitate easier maintenance activity, extend maintenance cycles, eliminate flight hardware contamination and reduce the amount of hazardous waste generated. This Joint Test Protocol (JTP) contains the critical requirements and tests necessary to qualify alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel Applications. These tests were derived from engineering, performance, and operational impact (supportability) requirements defined by a consensus of NASA and Air Force Space Command (AFSPC) participants. The Field Test Plan (FTP), entitled Joint Test Protocol for Validation of Alternative Low Emission Surface Preparation/Depainting Technologies for Structural Steel, prepared by ITB, defines the field evaluation and testing requirements for validating alternative surface preparation/depainting technologies and supplements the JTP.

  2. Bolted joints in graphite-epoxy composites

    NASA Technical Reports Server (NTRS)

    Hart-Smith, L. J.

    1976-01-01

    All-graphite/epoxy laminates and hybrid graphite-glass/epoxy laminates were tested. The tests encompassed a range of geometries for each laminate pattern to cover the three basic failure modes - net section tension failure through the bolt hole, bearing and shearout. Static tensile and compressive loads were applied. A constant bolt diameter of 6.35 mm (0.25 in.) was used in the tests. The interaction of stress concentrations associated with multi-row bolted joints was investigated by testing single- and double-row bolted joints and open-hole specimens in tension. For tension loading, linear interaction was found to exist between the bearing stress reacted at a given bolt hole and the remaining tension stress running by that hole to be reacted elsewhere. The interaction under compressive loading was found to be non-linear. Comparative tests were run using single-lap bolted joints and double-lap joints with pin connection. Both of these joint types exhibited lower strengths than were demonstrated by the corresponding double-lap joints. The analysis methods developed here for single bolt joints are shown to be capable of predicting the behavior of multi-row joints.

  3. Design, fabrication and test of graphite/polyimide composite joints and attachments for advanced aerospace vehicles

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Principal program activities dealt with the literature survey, design of joint concepts, assessment of GR/PI material quality, fabrication of test panels and specimens, and small specimen testing. Bonded and bolted designs are presented for each of the four major attachment types. Quality control data are presented for prepreg Lots 2W4651 and 3W2020. Preliminary design allowables test results for tension tests and compression tests of laminates are also presented.

  4. The top 50 cited articles on chordomas.

    PubMed

    Ikpeze, Tochukwu; Mesfin, Addisu

    2018-03-01

    Chordomas are rare malignant primary tumors of the spine. In the mobile spine and sacrum an en-bloc resection is associated with decreased rates of recurrence. Our objective was to identify the top cited articles in chordoma research and to further analyze characteristics of these articles. In March 2017, we used ISI Web of Science (v5.11, Thomas Reuter, Philadelphia, Pennsylvania, USA) to search for the following key word: "chordoma". Articles were searched from 1900 to 2017. Articles were ranked based on number of citations. The results were evaluated to determine articles most clinically relevant to the management of chordomas. The top 50 articles that met the search criteria were further characterized on the basis of: title, author, citation density, journal of publication, year (and decade) of publication, institution and country of origin and paper topic. A total of 1,043 articles matched the search criteria. The most influential 50 articles were cited 65 to 290 times. The articles were published between 1926 and 2012, and all articles were published in English. Thirty-three publications (66%) originated from the United States and seven (14%) from Italy. Cancer accounted for the most frequent (n=9) destination journal followed by Journal of Bone and Joint Surgery (n=4). A total of 41 institutions contributed to the top 50 articles. The most common article types were: clinical 44% (n=22), papers that combined clinical and pathology findings 18% (n=9) and basic science research 14% (n=7). The top 50 cited articles on chordomas are predominantly clinical papers, arising from the United States and most frequently published in Cancer and Journal of Bone and Joint Surgery .

  5. Joint High Speed Vessel (JHSV) Follow on Operational Test and Evaluation (FOT and E) Report

    DTIC Science & Technology

    2015-09-21

    Speed Vessel (JHSV) ship class. The events covered in this testing were not performed during the Initial Operational Test and Evaluation ( IOT &E...support boats since launch of these type boats was completed in IOT &E. 1 “Initial Operational Test...and Evaluation ( IOT &E) with Live Fire Test and Evaluation (LFT&E) on Joint High Speed Vessel (JHSV),” DOT&E, July 17, 2014. 2 MLP (CCS) is a heavy

  6. Immediate effects of bilateral manipulation of talocrural joints on standing stability in healthy subjects.

    PubMed

    Alburquerque-Sendín, Francisco; Fernández-de-las-Peñas, César; Santos-del-Rey, Miguel; Martín-Vallejo, Francisco Javier

    2009-02-01

    The purpose of this study was to investigate the immediate effects of bilateral talocrural joint manipulation on standing stability in healthy subjects. Sixty-two healthy subjects, 16 males and 46 females, aged from 18 to 32 years old (mean: 21+/-3 years old) participated in the study. Subjects were randomly divided into two groups: an intervention group (n=32), who received manipulation of bilateral talocrural joints and a control group (n=30) which did not receive any intervention. Baropodometric and stabilometric evaluations were assessed pre- and 5 min post-intervention by an assessor blinded to the treatment allocation. Intra-group and inter-group comparisons were analysed using appropriate parametric tests. The results indicated that changes on the X coordinate range, length of motion, and mean speed approximated to statistical significance (P=0.06), and changes on the Y coordinate range reached statistical significance (P=0.02). Average X and Y motions, and anterior-posterior or lateral velocities did not show significant differences. Our results showed that bilateral thrust manipulation of the talocrural joint did not modify standing stability, that is, the behavioural pattern of the projection of the centre of pressure, in healthy subjects.

  7. European Service Module Structural Test Article Load onto Transport Truck

    NASA Image and Video Library

    2017-06-21

    The Orion service module structural test article for Exploration Mission-1 (EM-1), built by the European Space Agency, is prepared for shipment to Lockheed Martin's Denver facility to undergo testing. Inside the Neil Armstrong Operations and Checkout Building high bay at NASA's Kennedy Space Center in Florida, a crane lifts the module onto a transport truck, where it is secured to be moved to the Shuttle Landing Facility for shipment. The Orion spacecraft will launch atop the agency's Space Launch System rocket on EM-1 in 2019.

  8. Orion EM-1 Crew Module Structural Test Article loaded onto Guppy

    NASA Image and Video Library

    2017-04-25

    NASA's Super Guppy aircraft has been closed and secured at the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. The Orion Exploration Mission-1 (EM-1) structural test article is secured inside the Super Guppy and will be transported to Lockheed Martin's Denver facility for testing. The Orion spacecraft will launch atop NASA’s Space Launch System rocket on EM-1, its first deep space mission.

  9. Testing of printed circuit board solder joints by optical correlation

    NASA Technical Reports Server (NTRS)

    Espy, P. N.

    1975-01-01

    An optical correlation technique for the nondestructive evaluation of printed circuit board solder joints was evaluated. Reliable indications of induced stress levels in solder joint lead wires are achievable. Definite relations between the inherent strength of a solder joint, with its associated ability to survive stress, are demonstrable.

  10. Techniques for Embedding Instrumentation in Pressure Vessel Test Articles

    NASA Technical Reports Server (NTRS)

    Cornelius, Michael

    2006-01-01

    Many interesting structural and thermal events occur in materials that are housed within a surrounding pressure vessel. In order to measure the environment during these events and explore their causes instrumentation must be installed on or in the material. Transducers can be selected that are small enough to be embedded within the test material but these instruments must interface with an external system in order to apply excitation voltages and output the desired data. The methods for installing the instrumentation and creating an interface are complicated when the material is located in a case or housing containing high pressures and hot gases. Installation techniques for overcoming some of these difficulties were developed while testing a series of small-scale solid propellant and hybrid rocket motors at Marshall Space Flight Center. These techniques have potential applications in other test articles where data are acquired from materials that require containment due to the severe environment encountered during the test process. This severe environment could include high pressure, hot gases, or ionized atmospheres. The development of these techniques, problems encountered, and the lessons learned from the ongoing testing process are summarized.

  11. Validation of a computational knee joint model using an alignment method for the knee laxity test and computed tomography.

    PubMed

    Kang, Kyoung-Tak; Kim, Sung-Hwan; Son, Juhyun; Lee, Young Han; Koh, Yong-Gon

    2017-01-01

    Computational models have been identified as efficient techniques in the clinical decision-making process. However, computational model was validated using published data in most previous studies, and the kinematic validation of such models still remains a challenge. Recently, studies using medical imaging have provided a more accurate visualization of knee joint kinematics. The purpose of the present study was to perform kinematic validation for the subject-specific computational knee joint model by comparison with subject's medical imaging under identical laxity condition. The laxity test was applied to the anterior-posterior drawer under 90° flexion and the varus-valgus under 20° flexion with a series of stress radiographs, a Telos device, and computed tomography. The loading condition in the computational subject-specific knee joint model was identical to the laxity test condition in the medical image. Our computational model showed knee laxity kinematic trends that were consistent with the computed tomography images, except for negligible differences because of the indirect application of the subject's in vivo material properties. Medical imaging based on computed tomography with the laxity test allowed us to measure not only the precise translation but also the rotation of the knee joint. This methodology will be beneficial in the validation of laxity tests for subject- or patient-specific computational models.

  12. Thiokol/Wasatch installation evaluation of the redesigned field joint protection system (concepts 1 and 3)

    NASA Technical Reports Server (NTRS)

    Cook, M.

    1989-01-01

    The procedures, performance, and results obtained from the Thiokol Corporation/Wasatch Redesigned Field Joint Protection System (FJPS) Installation Evaluation are documented. The purpose of the evaluation was to demonstrate and develop the procedures required to install two different concepts (referred to as Concepts 1 and 3) of the redesigned FJPS. The processing capability of each configuration was then evaluated and compared. The FJPS is installed on redesigned solid rocket motors (RSRM) to protect the field joints from rain intrusion and to maintain the joint temperature sensor measurement between 85 and 122 F while the boosters are on the launch pad. The FJPS is being redesigned to reduce installation timelines at KSC and to simplify or eliminate installation processing problems related to the present design of an EPDM moisture seal/extruded cork combination. Several installation techniques were evaluated, and a preferred method of application was developed for each concept. The installations were performed with the test article in the vertical (flight) position. Comparative timelines between the two concepts were also developed. An additional evaluation of the Concept 3 configuration was performed with the test article in the horizontal position, to simulate an overhead installation on a technical evaluation motor (TEM).

  13. Thermal and Fluid Modeling of the CRYogenic Orbital TEstbed (CRYOTE) Ground Test Article (GTA)

    NASA Technical Reports Server (NTRS)

    Piryk, David; Schallhorn, Paul; Walls, Laurie; Stopnitzky, Benny; Rhys, Noah; Wollen, Mark

    2012-01-01

    The purpose of this study was to anchor thermal and fluid system models to data acquired from a ground test article (GTA) for the CRYogenic Orbital TEstbed - CRYOTE. To accomplish this analysis, it was broken into four primary tasks. These included model development, pre-test predictions, testing support at Marshall Space Flight Center (MSFC} and post-test correlations. Information from MSFC facilitated the task of refining and correlating the initial models. The primary goal of the modeling/testing/correlating efforts was to characterize heat loads throughout the ground test article. Significant factors impacting the heat loads included radiative environments, multi-layer insulation (MLI) performance, tank fill levels, tank pressures, and even contact conductance coefficients. This paper demonstrates how analytical thermal/fluid networks were established, and it includes supporting rationale for specific thermal responses seen during testing.

  14. Igniter adapter-to-igniter chamber deflection test

    NASA Technical Reports Server (NTRS)

    Cook, M.

    1990-01-01

    Testing was performed to determine the maximum RSRM igniter adapter-to-igniter chamber joint deflection at the crown of the inner joint primary seal. The deflection data was gathered to support igniter inner joint gasket resiliency predictions which led to launch commit criteria temperature determinations. The proximity (deflection) gage holes for the first test (Test No. 1) were incorrectly located; therefore, the test was declared a non-test. Prior to Test No. 2, test article configuration was modified with the correct proximity gage locations. Deflection data were successfully acquired during Test No. 2. However, the proximity gage deflection measurements were adversely affected by temperature increases. Deflections measured after the temperature rise at the proximity gages were considered unreliable. An analysis was performed to predict the maximum deflections based on the reliable data measured before the detectable temperature rise. Deflections to the primary seal crown location were adjusted to correspond to the time of maximum expected operating pressure (2,159 psi) to account for proximity gage bias, and to account for maximum attach and special bolt relaxation. The maximum joint deflection for the igniter inner joint at the crown of the primary seal, accounting for all significant correction factors, was 0.0031 in. (3.1 mil). Since the predicted (0.003 in.) and tested maximum deflection values were sufficiently close, the launch commit criteria was not changed as a result of this test. Data from this test should be used to determine if the igniter inner joint gasket seals are capable of maintaining sealing capability at a joint displacement of (1.4) x (0.0031 in.) = 0.00434 inches. Additional testing should be performed to increase the database on igniter deflections and address launch commit criteria temperatures.

  15. Debonding of Stitched Composite Joints: Testing and Analysis

    NASA Technical Reports Server (NTRS)

    Glaessgen, E. H.; Raju, I. S.; Poe, C. C., Jr.

    1999-01-01

    The effect of stitches on the failure of a single lap joint configuration was determined in a combined experimental and analytical study. The experimental study was conducted to determine debond growth under static monotonic loading. The stitches were shown to delay the initiation ofthe debond and provide load transfer beyond the load necessary to completely debond the stitched lap joint. The strain energy release rates at the debond front were calculated using a finite element-based technique. Models of the unstitched configuration showed significant values of modes I and II across the width of the joint and showed that mode III is zero at the centerline but increases near the free edge. Models of the stitched configuration showed that the stitches effectively reduced mode I to zero, but had less of an effect on modes II and III.

  16. Advances in Proximal Interphalangeal Joint Arthroplasty: Biomechanics and Biomaterials.

    PubMed

    Zhu, Andy F; Rahgozar, Paymon; Chung, Kevin C

    2018-05-01

    Proximal interphalangeal (PIP) joint arthritis is a debilitating condition. The complexity of the joint makes management particularly challenging. Treatment of PIP arthritis requires an understanding of the biomechanics of the joint. PIP joint arthroplasty is one treatment option that has evolved over time. Advances in biomaterials have improved and expanded arthroplasty design. This article reviews biomechanics and arthroplasty design of the PIP joint. Copyright © 2018 Elsevier Inc. All rights reserved.

  17. Acquisition/expulsion system for earth orbital propulsion system study. Volume 4: Flight test article

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Two orbital test plans were prepared to verify one of the passive cryogenic storage tank/feedline candidate designs. One plan considered the orbital test article to be launched as a dedicated payload using an Atlas F burner launching configuration. The second plan proposed to launch the orbital test article as a secondary payload on the Titan E/Centaur proof flight. The secondary payload concept was pursued until January 1973, when work to build the hardware for this phase of the contract was terminated for lack of a sponsor for the flight. The dedicated payload launched on an Atlas F is described.

  18. The effects of additives to SnAgCu alloys on microstructure and drop impact reliability of solder joints

    NASA Astrophysics Data System (ADS)

    Liu, Weiping; Lee, Ning-Cheng

    2007-07-01

    The impact reliability of solder joints in electronic packages is critical to the lifetime of electronic products, especially those portable devices using area array packages such as ball-grid array (BGA) and chip-scale packages (CSP). Currently, SnAgCu (SAC) solders are most widely used for lead-free applications. However, BGA and CSP solder joints using SAC alloys are fragile and prone to premature interfacial failure, especially under shock loading. To further enhance impact reliability, a family of SAC alloys doped with a small amount of additives such as Mn, Ce, Ti, Bi, and Y was developed. The effects of doping elements on drop test performance, creep resistance, and microstructure of the solder joints were investigated, and the solder joints made with the modified alloys exhibited significantly higher impact reliability.

  19. Correlation Results for a Mass Loaded Vehicle Panel Test Article Finite Element Models and Modal Survey Tests

    NASA Technical Reports Server (NTRS)

    Maasha, Rumaasha; Towner, Robert L.

    2012-01-01

    High-fidelity Finite Element Models (FEMs) were developed to support a recent test program at Marshall Space Flight Center (MSFC). The FEMs correspond to test articles used for a series of acoustic tests. Modal survey tests were used to validate the FEMs for five acoustic tests (a bare panel and four different mass-loaded panel configurations). An additional modal survey test was performed on the empty test fixture (orthogrid panel mounting fixture, between the reverb and anechoic chambers). Modal survey tests were used to test-validate the dynamic characteristics of FEMs used for acoustic test excitation. Modal survey testing and subsequent model correlation has validated the natural frequencies and mode shapes of the FEMs. The modal survey test results provide a basis for the analysis models used for acoustic loading response test and analysis comparisons

  20. Development of Test Article Building Block (TABB) for deployable platform systems

    NASA Technical Reports Server (NTRS)

    Greenberg, H. S.; Barbour, R. T.

    1984-01-01

    The concept of a Test Article Building Block (TABB) is described. The TABB is a ground test article that is representative of a future building block that can be used to construct LEO and GEO deployable space platforms for communications and scientific payloads. This building block contains a main housing within which the entire structure, utilities, and deployment/retraction mechanism are stowed during launch. The end adapter secures the foregoing components to the housing during launch. The main housing and adapter provide the necessary building-block-to-building-block attachments for automatically deployable platforms. Removal from the shuttle cargo bay can be accomplished with the remote manipulator system (RMS) and/or the handling and positioning aid (HAPA). In this concept, all the electrical connections are in place prior to launch with automatic latches for payload attachment provided on either the end adapters or housings. The housings also can contain orbiter docking ports for payload installation and maintenance.

  1. Recent advances in computational mechanics of the human knee joint.

    PubMed

    Kazemi, M; Dabiri, Y; Li, L P

    2013-01-01

    Computational mechanics has been advanced in every area of orthopedic biomechanics. The objective of this paper is to provide a general review of the computational models used in the analysis of the mechanical function of the knee joint in different loading and pathological conditions. Major review articles published in related areas are summarized first. The constitutive models for soft tissues of the knee are briefly discussed to facilitate understanding the joint modeling. A detailed review of the tibiofemoral joint models is presented thereafter. The geometry reconstruction procedures as well as some critical issues in finite element modeling are also discussed. Computational modeling can be a reliable and effective method for the study of mechanical behavior of the knee joint, if the model is constructed correctly. Single-phase material models have been used to predict the instantaneous load response for the healthy knees and repaired joints, such as total and partial meniscectomies, ACL and PCL reconstructions, and joint replacements. Recently, poromechanical models accounting for fluid pressurization in soft tissues have been proposed to study the viscoelastic response of the healthy and impaired knee joints. While the constitutive modeling has been considerably advanced at the tissue level, many challenges still exist in applying a good material model to three-dimensional joint simulations. A complete model validation at the joint level seems impossible presently, because only simple data can be obtained experimentally. Therefore, model validation may be concentrated on the constitutive laws using multiple mechanical tests of the tissues. Extensive model verifications at the joint level are still crucial for the accuracy of the modeling.

  2. Imaging of the temporomandibular joint: An update

    PubMed Central

    Bag, Asim K; Gaddikeri, Santhosh; Singhal, Aparna; Hardin, Simms; Tran, Benson D; Medina, Josue A; Curé, Joel K

    2014-01-01

    Imaging of the temporomandibular joint (TMJ) is continuously evolving with advancement of imaging technologies. Many different imaging modalities are currently used to evaluate the TMJ. Magnetic resonance imaging is commonly used for evaluation of the TMJ due to its superior contrast resolution and its ability to acquire dynamic imaging for demonstration of the functionality of the joint. Computed tomography and ultrasound imaging have specific indication in imaging of the TMJ. This article focuses on state of the art imaging of the temporomandibular joint. Relevant normal anatomy and biomechanics of movement of the TMJ are discussed for better understanding of many TMJ pathologies. Imaging of internal derangements is discussed in detail. Different arthropathies and common tumors are also discussed in this article. PMID:25170394

  3. [Development of Chinese forensic Y-STR DNA database].

    PubMed

    Ge, Jian-Ye; Yan, Jiang-Wei; Xie, Qun; Sun, Hong-Yu; Zhou, Huai-Gu; Li, Bin

    2013-06-01

    Y chromosome is a male-specific paternal inherited chromosome. The STR markers on Y chromosome have been widely used in forensic practices. This article summarizes the characteristics of Y-STR and some factors are considered of selecting appropriate Y-STR markers for Chinese population. The prospects of existing and potential forensic applications of Y-STR profiles are discussed including familial excluding, familial searching, crowd source deducing, mixture sample testing, and kinship identifying. The research, development, verification of Y-STR kit, Y-STR mutation rate, and search software are explored and some suggestions are given.

  4. Development of an above-knee prosthesis equipped with a microcomputer-controlled knee joint: first test results.

    PubMed

    Aeyels, B; Peeraer, L; Vander Sloten, J; Van der Perre, G

    1992-05-01

    The shortcomings of conventional above-knee prostheses are due to their lack of adaptive control. Implementation of a microcomputer controlling the knee joint in a passive way has been suggested to enhance the patient's gait comfort, safety and cosmesis. This approach was used in the design of a new prosthetic system for the above-knee amputee, and tested on one patient. The knee joint of a conventional, modular prosthesis was replaced by a knee joint mechanism, equipped with a controllable brake on the knee joint axis. Sensors and a microcomputer were added, keeping the system self-contained. The modularity of the design permits the use of an alternative, external, PC-based control unit, emulating the self-contained one, and offering extended data monitoring and storage facilities. For both units an operating environment was written, including sensor/actuator interfacing and the implementation of a real-time interrupt, executing the control algorithm. A double finite state approach was used in the design of the control algorithm. On a higher level, the mode identification algorithm reveals the patient's intent. Within a specific mode (lower level), the relevant mode control algorithm looks for the current phase within the gait cycle. Within a particular phase, a specific simple control action with the brake replaces normal knee muscle activity. Tests were carried out with one prosthetic patient using a basic control algorithm for level walking, allowing controlled knee flexion during stance phase. The technical feasibility of such a concept is illustrated by the test results, even though only flexion during early stance phase was controlled during the trials.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. An experimental and morphometric test of the relationship between vertebral morphology and joint stiffness in Nile crocodiles (Crocodylus niloticus).

    PubMed

    Molnar, Julia L; Pierce, Stephanie E; Hutchinson, John R

    2014-03-01

    Despite their semi-aquatic mode of life, modern crocodylians use a wide range of terrestrial locomotor behaviours, including asymmetrical gaits otherwise only found in mammals. The key to these diverse abilities may lie in the axial skeleton. Correlations between vertebral morphology and both intervertebral joint stiffness and locomotor behaviour have been found in other animals, but the vertebral mechanics of crocodylians have not yet been experimentally and quantitatively tested. We measured the passive mechanics and morphology of the thoracolumbar vertebral column in Crocodylus niloticus in order to validate a method to infer intervertebral joint stiffness based on morphology. Passive stiffness of eight thoracic and lumbar joints was tested in dorsal extension, ventral flexion and mediolateral flexion using cadaveric specimens. Fifteen measurements that we deemed to be potential correlates of stiffness were taken from each vertebra and statistically tested for correlation with joint stiffness. We found that the vertebral column of C. niloticus is stiffer in dorsoventral flexion than in lateral flexion and, in contrast to that of many mammals, shows an increase in joint stiffness in the lumbar region. Our findings suggest that the role of the axial column in crocodylian locomotion may be functionally different from that in mammals, even during analogous gaits. A moderate proportion of variation in joint stiffness (R(2)=0.279-0.520) was predicted by centrum width and height, neural spine angle and lamina width. These results support the possible utility of some vertebral morphometrics in predicting mechanical properties of the vertebral column in crocodiles, which also should be useful for forming functional hypotheses of axial motion during locomotion in extinct archosaurs.

  6. Home and Where the Heart Is: Marriage Timing and Joint Home Purchase

    PubMed Central

    Holland, Jennifer A.

    2011-01-01

    This article evaluates the relationship between the timing of marriage and the purchase of a jointly owned home among Swedish cohabiting couples. Data for this analysis come from the Swedish Housing and Life Course Cohort Study (N = 1,596 couples; 2,006 cohabiting spells). The author develops models to proxy for simultaneity and intentions and test hypotheses about positive and negative and long- and short-run relationships between the two life-course events. The author uses a novel modeling approach, allowing for differences in the risk before, concurrently and after the conditioning event. Results indicate a positive relationship between marriage and joint home purchase and suggest the possibility of an ordering of events: For some couples, formalizing their union through marriage may be a prerequisite for a joint home purchase. PMID:22581991

  7. Effects of joints in truss structures

    NASA Technical Reports Server (NTRS)

    Ikegami, R.

    1988-01-01

    The response of truss-type structures for future space applications, such as Large Deployable Reflector (LDR), will be directly affected by joint performance. Some of the objectives of research at BAC were to characterize structural joints, establish analytical approaches that incorporate joint characteristics, and experimentally establish the validity of the analytical approaches. The test approach to characterize joints for both erectable and deployable-type structures was based upon a Force State Mapping Technique. The approach pictorially shows how the nonlinear joint results can be used for equivalent linear analysis. Testing of the Space Station joints developed at LaRC (a hinged joint at 2 Hz and a clevis joint at 2 Hz) successfully revealed the nonlinear characteristics of the joints. The Space Station joints were effectively linear when loaded to plus or minus 500 pounds with a corresponding displacement of about plus or minus 0.0015 inch. It was indicated that good linear joints exist which are compatible with errected structures, but that difficulty may be encountered if nonlinear-type joints are incorporated in the structure.

  8. Stress Behaviour in Compression of Contact-Monolithic Joint of Self-Supporting Wall of Large Panel Multi-Storey Building

    NASA Astrophysics Data System (ADS)

    Derbentsev, I.; Karyakin, A. A.; Volodin, A.

    2017-11-01

    The article deals with the behaviour of a contact-monolithic joint of large-panel buildings under compression. It gives a detailed analysis and the descriptions of the stages of such joints failure based on the results of the tests and computational modelling. The article is of interest to specialists who deal with computational modelling or the research of large-panel multi-storey buildings. The text gives a valuable information on the values of their bearing capacity and flexibility, the eccentricity of load transfer from upper panel to lower, the value of thrust passed to a ceiling panel. Recommendations are given to estimate all the above-listed parameters.

  9. [Sports participation after joint arthroplasty].

    PubMed

    Dauty, M; Letenneur, J

    2007-12-01

    To recommand sports activities after joint arthroplasty from the literature analysis, the French surgeon's opinion and wish patients. From the Medline data base interrogation according to keywords: Sports, Arthroplasty, Athletics, Physical training, two different readers, an orthopedic surgeon and a Physical Medicine and Rehabilitation physician selected articles in French or English language according to the level of proofs of the french classification of the Accreditation and Health Evaluation National Agency (Anaes). Professional practices were estimated by the interrogation of 30 orthopedic surgeons members of the french West Orthopaedics Society (SOO). The demand of sports practice was studied with patients recently operated for a primary total knee arthroplasty (TKA) after gonarthrosis. Twenty-two articles were selected from 305 articles obtained by the search according to keywords. Ten literature reviews are limited by the absence of prospective randomized study. A level II study and eleven level IV articles are reported. According to the subjective orthropedic surgeon's opinion, the objective results based on the joint load studied and the percentage of arthroplasty revision, sport is beneficial for the individual health but perhaps not for the arthroplasty survey. However, aerobic and leisure activities are recommended (walking, swimming, cycling) in agreement with the demand of the patients recently operated with a TKA. TKA differs from Total Hip Arthroplasty for jogging because of knee joint constraints during the knee flexion. A single study reports sports possibilities after shoulder arthroplasty and ankle arthroplasty and no study reports results after elbow arthroplasty.

  10. Objective Assessment of Joint Stiffness: A Clinically Oriented Hardware and Software Device with an Application to the Shoulder Joint.

    PubMed

    McQuade, Kevin; Price, Robert; Liu, Nelson; Ciol, Marcia A

    2012-08-30

    Examination of articular joints is largely based on subjective assessment of the "end-feel" of the joint in response to manually applied forces at different joint orientations. This technical report aims to describe the development of an objective method to examine joints in general, with specific application to the shoulder, and suitable for clinical use. We adapted existing hardware and developed laptop-based software to objectively record the force/displacement behavior of the glenohumeral joint during three common manual joint examination tests with the arm in six positions. An electromagnetic tracking system recorded three-dimensional positions of sensors attached to a clinician examiner and a patient. A hand-held force transducer recorded manually applied translational forces. The force and joint displacement were time-synchronized and the joint stiffness was calculated as a quantitative representation of the joint "end-feel." A methodology and specific system checks were developed to enhance clinical testing reproducibility and precision. The device and testing protocol were tested on 31 subjects (15 with healthy shoulders, and 16 with a variety of shoulder impairments). Results describe the stiffness responses, and demonstrate the feasibility of using the device and methods in clinical settings.

  11. Buckling of a Longitudinally Jointed Curved Composite Panel Arc Segment for Next Generation of Composite Heavy Lift Launch Vehicles: Verification Testing Analysis

    NASA Technical Reports Server (NTRS)

    Farrokh, Babak; Segal, Kenneth N.; Akkerman, Michael; Glenn, Ronald L.; Rodini, Benjamin T.; Fan, Wei-Ming; Kellas, Sortiris; Pineda, Evan J.

    2014-01-01

    In this work, an all-bonded out-of-autoclave (OoA) curved longitudinal composite joint concept, intended for use in the next generation of composite heavy lift launch vehicles, was evaluated and verified through finite element (FE) analysis, fabrication, testing, and post-test inspection. The joint was used to connect two curved, segmented, honeycomb sandwich panels representative of a Space Launch System (SLS) fairing design. The overall size of the resultant panel was 1.37 m by 0.74 m (54 in by 29 in), of which the joint comprised a 10.2 cm (4 in) wide longitudinal strip at the center. NASTRAN and ABAQUS were used to perform linear and non-linear analyses of the buckling and strength performance of the jointed panel. Geometric non-uniformities (i.e., surface contour imperfections) were measured and incorporated into the FE model and analysis. In addition, a sensitivity study of the specimens end condition showed that bonding face-sheet doublers to the panel's end, coupled with some stress relief features at corner-edges, can significantly reduce the stress concentrations near the load application points. Ultimately, the jointed panel was subjected to a compressive load. Load application was interrupted at the onset of buckling (at 356 kN 80 kips). A post-test non-destructive evaluation (NDE) showed that, as designed, buckling occurred without introducing any damage into the panel or the joint. The jointed panel was further capable of tolerating an impact damage to the same buckling load with no evidence of damage propagation. The OoA cured all-composite joint shows promise as a low mass factory joint for segmented barrels.

  12. An Evaluation of the Additional Acoustic Power Needed to Overcome the Effects of a Test-Article's Absorption During Reverberant Chamber Acoustic Testing of Spaceflight Hardware

    NASA Technical Reports Server (NTRS)

    Hozman, Aron D.; Hughes, William O.

    2014-01-01

    The exposure of a customer's aerospace test-article to a simulated acoustic launch environment is typically performed in a reverberant acoustic test chamber. The acoustic pre-test runs that will ensure that the sound pressure levels of this environment can indeed be met by a test facility are normally performed without a test-article dynamic simulator of representative acoustic absorption and size. If an acoustic test facility's available acoustic power capability becomes maximized with the test-article installed during the actual test then the customer's environment requirement may become compromised. In order to understand the risk of not achieving the customer's in-tolerance spectrum requirement with the test-article installed, an acoustic power margin evaluation as a function of frequency may be performed by the test facility. The method for this evaluation of acoustic power will be discussed in this paper. This method was recently applied at the NASA Glenn Research Center Plum Brook Station's Reverberant Acoustic Test Facility for the SpaceX Falcon 9 Payload Fairing acoustic test program.

  13. An Evaluation of the Additional Acoustic Power Needed to Overcome the Effects of a Test-Article's Absorption during Reverberant Chamber Acoustic Testing of Spaceflight Hardware

    NASA Technical Reports Server (NTRS)

    Hozman, Aron D.; Hughes, William O.

    2014-01-01

    The exposure of a customers aerospace test-article to a simulated acoustic launch environment is typically performed in a reverberant acoustic test chamber. The acoustic pre-test runs that will ensure that the sound pressure levels of this environment can indeed be met by a test facility are normally performed without a test-article dynamic simulator of representative acoustic absorption and size. If an acoustic test facilitys available acoustic power capability becomes maximized with the test-article installed during the actual test then the customers environment requirement may become compromised. In order to understand the risk of not achieving the customers in-tolerance spectrum requirement with the test-article installed, an acoustic power margin evaluation as a function of frequency may be performed by the test facility. The method for this evaluation of acoustic power will be discussed in this paper. This method was recently applied at the NASA Glenn Research Center Plum Brook Stations Reverberant Acoustic Test Facility for the SpaceX Falcon 9 Payload Fairing acoustic test program.

  14. Image-Guided Surgical Robotic System for Percutaneous Reduction of Joint Fractures.

    PubMed

    Dagnino, Giulio; Georgilas, Ioannis; Morad, Samir; Gibbons, Peter; Tarassoli, Payam; Atkins, Roger; Dogramadzi, Sanja

    2017-11-01

    Complex joint fractures often require an open surgical procedure, which is associated with extensive soft tissue damages and longer hospitalization and rehabilitation time. Percutaneous techniques can potentially mitigate these risks but their application to joint fractures is limited by the current sub-optimal 2D intra-operative imaging (fluoroscopy) and by the high forces involved in the fragment manipulation (due to the presence of soft tissue, e.g., muscles) which might result in fracture malreduction. Integration of robotic assistance and 3D image guidance can potentially overcome these issues. The authors propose an image-guided surgical robotic system for the percutaneous treatment of knee joint fractures, i.e., the robot-assisted fracture surgery (RAFS) system. It allows simultaneous manipulation of two bone fragments, safer robot-bone fixation system, and a traction performing robotic manipulator. This system has led to a novel clinical workflow and has been tested both in laboratory and in clinically relevant cadaveric trials. The RAFS system was tested on 9 cadaver specimens and was able to reduce 7 out of 9 distal femur fractures (T- and Y-shape 33-C1) with acceptable accuracy (≈1 mm, ≈5°), demonstrating its applicability to fix knee joint fractures. This study paved the way to develop novel technologies for percutaneous treatment of complex fractures including hip, ankle, and shoulder, thus representing a step toward minimally-invasive fracture surgeries.

  15. A Conditional Joint Modeling Approach for Locally Dependent Item Responses and Response Times

    ERIC Educational Resources Information Center

    Meng, Xiang-Bin; Tao, Jian; Chang, Hua-Hua

    2015-01-01

    The assumption of conditional independence between the responses and the response times (RTs) for a given person is common in RT modeling. However, when the speed of a test taker is not constant, this assumption will be violated. In this article we propose a conditional joint model for item responses and RTs, which incorporates a covariance…

  16. SLS Engine Section Test Article Loaded on Barge Pegasus at NASA's Michoud Assembly Facility

    NASA Image and Video Library

    2017-04-27

    A NASA move team loaded the engine section structural qualification test article for the Space Launch System into the barge Pegasus docked in the harbor at NASA's Michoud Assembly Facility in New Orleans. The rocket's engine section is the bottom of the core stage and houses the four RS-25 engines. The engine section test article was moved from Building 103, Michoud’s 43-acre rocket factory, to the barge where it was loaded for a river trip to NASA’s Marshall Space Flight Center in Huntsville, Alabama. The bottom part of the test article is structurally the same as the engine section that will be flown as part of the SLS core stage. The shiny metal top part simulates the rocket's liquid hydrogen tank, which is the fuel tank that joins to the engine section. The barge Pegasus will travel 1,240 miles by river to Marshall and endure tests that pull, push, and bend it, subjecting it to millions of pounds of force. This ensures the structure can withstand the incredible stresses produced by the 8.8 million pounds of thrust during launch and ascent.

  17. Joint helmet-mounted cueing system (JHMCS) helmet qualification testing requirements

    NASA Astrophysics Data System (ADS)

    Orf, Garry W.

    1998-08-01

    The Joint Helmet-Mounted Cueing System (JHMCS) program will provide capability to cue high off-boresight (HOBS) weapons to the operator's line of sight and to confirm weapon sensor LOS for the US Air Force and US Navy (USN) aircrew. This capability will ensure the USAF and USN pilots a first shot opportunity. The JHMCS incorporates an ejection-compatible helmet-mounted display system that will be installed on F- 15, F-16, F/A-18, and F-22 aircraft. The JHMCS includes a flight helmet with display optics, miniature cathode ray tube, magnetic receiver unit, miniature camera, automatic brightness control sensor, and microcontroller. The flight helmet for JHMCS is based on the new lightweight HGU-55A/P. This paper describes the requirements for the helmet qualification tests including: windblast, ejection tower, hanging harness, centrifuge, mass properties, energy attenuation and penetration resistance, noise attenuation, visor characteristics, compatibility demonstration, sled/in- flight ejection, water survival, standard conditions and environment. The test objective, success criteria, equipment configuration, and data collection requirements for each test is discussed.

  18. Testing Programs in Schools: What's New? A Special Issue.

    ERIC Educational Resources Information Center

    Walter, L. James; And Others

    1981-01-01

    This special issue of "Catalyst", entitled Testing Programs in Schools: What's New?, was published jointly by the Nebraska Council of School Administrators and the Nebraska Association for Supervision and Curriculum. The articles emphasize desirability of designing testing programs to meet the information needs of educators and the…

  19. Development and Validation of a Pressurization System Model for a Crossfeed Subscale Water Test Article

    NASA Technical Reports Server (NTRS)

    Nguyen, Han; Mazurkivich, Pete

    2006-01-01

    A pressurization system model was developed for a crossfeed subscale water test article using the EASY5 modeling software. The model consisted of an integrated tank pressurization and pressurization line model. The tank model was developed using the general purpose library, while the line model was assembled from the gas dynamic library. The pressurization system model was correlated to water test data obtained from nine test runs conducted on the crossfeed subscale test article. The model was first correlated to a representative test run and frozen. The correlated model was then used to predict the tank pressures and compared with the test data for eight other runs. The model prediction showed excellent agreement with the test data, allowing it to be used in a later study to analyze the pressurization system performance of a full-scale bimese vehicle with cryogenic propellants.

  20. Model test study on propagation law of plane stress wave in jointed rock mass under different in-situ stresses

    NASA Astrophysics Data System (ADS)

    Dong, Qian

    2017-12-01

    The study of propagation law of plane stress wave in jointed rock mass under in-situ stress has important significance for safety excavation of underground rock mass engineering. A model test of the blasting stress waves propagating in the intact rock and jointed rock mass under different in-situ stresses was carried out, and the influencing factors on the propagation law, such as the scale of static loads and the number of joints were studied respectively. The results show that the transmission coefficient of intact rock is larger than that of jointed rock mass under the same loading condition. With the increase of confining pressure, the transmission coefficients of intact rock and jointed rock mass both show an trend of increasing first and then decreasing, and the variation of transmission coefficients in intact rock is smaller than that of jointed rock mass. Transmission coefficient of jointed rock mass decreases with the increase of the number of joints under the same loading condition, when the confining pressure is relatively small, the reduction of transmission coefficients decreases with the increasing of the number of joints, and the variation law of the reduction of transmission coefficients is contrary when the confining pressure is large.

  1. An Evaluation of the Additional Acoustic Power Needed to Overcome the Effects of a Test-Articles Absorption During Reverberant Chamber Acoustic Testing of Spaceflight Hardware

    NASA Technical Reports Server (NTRS)

    Hozman, Aron D.; Hughes, William O.

    2014-01-01

    It is important to realize that some test-articles may have significant sound absorption that may challenge the acoustic power capabilities of a test facility. Therefore, to mitigate this risk of not being able to meet the customers target spectrum, it is prudent to demonstrate early-on an increased acoustic power capability which compensates for this test-article absorption. This paper describes a concise method to reduce this risk when testing aerospace test-articles which have significant absorption. This method was successfully applied during the SpaceX Falcon 9 Payload Fairing acoustic test program at the NASA Glenn Research Center Plum Brook Stations RATF.

  2. Recent Advances in Computational Mechanics of the Human Knee Joint

    PubMed Central

    Kazemi, M.; Dabiri, Y.; Li, L. P.

    2013-01-01

    Computational mechanics has been advanced in every area of orthopedic biomechanics. The objective of this paper is to provide a general review of the computational models used in the analysis of the mechanical function of the knee joint in different loading and pathological conditions. Major review articles published in related areas are summarized first. The constitutive models for soft tissues of the knee are briefly discussed to facilitate understanding the joint modeling. A detailed review of the tibiofemoral joint models is presented thereafter. The geometry reconstruction procedures as well as some critical issues in finite element modeling are also discussed. Computational modeling can be a reliable and effective method for the study of mechanical behavior of the knee joint, if the model is constructed correctly. Single-phase material models have been used to predict the instantaneous load response for the healthy knees and repaired joints, such as total and partial meniscectomies, ACL and PCL reconstructions, and joint replacements. Recently, poromechanical models accounting for fluid pressurization in soft tissues have been proposed to study the viscoelastic response of the healthy and impaired knee joints. While the constitutive modeling has been considerably advanced at the tissue level, many challenges still exist in applying a good material model to three-dimensional joint simulations. A complete model validation at the joint level seems impossible presently, because only simple data can be obtained experimentally. Therefore, model validation may be concentrated on the constitutive laws using multiple mechanical tests of the tissues. Extensive model verifications at the joint level are still crucial for the accuracy of the modeling. PMID:23509602

  3. Testing the limits of the 'joint account' model of genetic information: a legal thought experiment.

    PubMed

    Foster, Charles; Herring, Jonathan; Boyd, Magnus

    2015-05-01

    We examine the likely reception in the courtroom of the 'joint account' model of genetic confidentiality. We conclude that the model, as modified by Gilbar and others, is workable and reflects, better than more conventional legal approaches, both the biological and psychological realities and the obligations owed under Articles 8 and 10 of the European Convention on Human Rights (ECHR). Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  4. Experimental characterization of deployable trusses and joints

    NASA Technical Reports Server (NTRS)

    Ikegami, R.; Church, S. M.; Keinholz, D. A.; Fowler, B. L.

    1987-01-01

    The structural dynamic properties of trusses are strongly affected by the characteristics of joints connecting the individual beam elements. Joints are particularly significant in that they are often the source of nonlinearities and energy dissipation. While the joints themselves may be physically simple, direct measurement is often necessary to obtain a mathematical description suitable for inclusion in a system model. Force state mapping is a flexible, practical test method for obtaining such a description, particularly when significant nonlinear effects are present. It involves measurement of the relationship, nonlinear or linear, between force transmitted through a joint and the relative displacement and velocity across it. An apparatus and procedure for force state mapping are described. Results are presented from tests of joints used in a lightweight, composite, deployable truss built by the Boeing Aerospace Company. The results from the joint tests are used to develop a model of a full 4-bay truss segment. The truss segment was statically and dynamically tested. The results of the truss tests are presented and compared with the analytical predictions from the model.

  5. Robotic joint experiments under ultravacuum

    NASA Technical Reports Server (NTRS)

    Borrien, A.; Petitjean, L.

    1988-01-01

    First, various aspects of a robotic joint development program, including gearbox technology, electromechanical components, lubrication, and test results, are discussed. Secondly, a test prototype of the joint allowing simulation of robotic arm dynamic effects is presented. This prototype is tested under vacuum with different types of motors and sensors to characterize the functional parameters: angular position error, mechanical backlash, gearbox efficiency, and lifetime.

  6. Reliability and number of trials of Y Balance Test in adolescent athletes.

    PubMed

    Linek, Pawel; Sikora, Damian; Wolny, Tomasz; Saulicz, Edward

    2017-10-01

    The Star Excursion Balance Test (SEBT) is commonly used to evaluate dynamic equilibrium. The Y Balance Test (Y-BT) is a shortened version of the SEBT where a Y- Balance Kit is commonly used. To date, research concerning the protocol and reliability of the SEBT and Y-BT has been conducted only for adults. The aim of the study was to assess the protocol (the necessary number of trials to stabilize the results) and reliability of the Y-BT in adolescent athletes. One-way repeated-measures analysis of variance (ANOVA) and reliability study. The sample of 38 athletes (mean age: 15.6 years) was selected from a football club. A Y-Balance test kit was applied for the evaluation of dynamic balance. The analysis used the values normalized to the relative length of the lower limbs. After six attempts, three consecutive ones achieved stability for all directions and both extremities (p > 0.05). The intraclass correlation coefficient (ICC 3,1 ), standard error of measurement and minimal detectable change values for the three attempts ranged from 0.57 to 0.82, from 3 to less than 6% and from 7.68 to 13.7%, respectively. In the study of adolescent dynamic equilibrium using the Y-BT, it is recommended to perform nine attempts (including six trial attempts and three measurements). In order to increase reliability it is recommended that the average of the three measured attempts is analysed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Finite Elements Analysis of a Composite Semi-Span Test Article With and Without Discrete Damage

    NASA Technical Reports Server (NTRS)

    Lovejoy, Andrew E.; Jegley, Dawn C. (Technical Monitor)

    2000-01-01

    AS&M Inc. performed finite element analysis, with and without discrete damage, of a composite semi-span test article that represents the Boeing 220-passenger transport aircraft composite semi-span test article. A NASTRAN bulk data file and drawings of the test mount fixtures and semi-span components were utilized to generate the baseline finite element model. In this model, the stringer blades are represented by shell elements, and the stringer flanges are combined with the skin. Numerous modeling modifications and discrete source damage scenarios were applied to the test article model throughout the course of the study. This report details the analysis method and results obtained from the composite semi-span study. Analyses were carried out for three load cases: Braked Roll, LOG Down-Bending and 2.5G Up-Bending. These analyses included linear and nonlinear static response, as well as linear and nonlinear buckling response. Results are presented in the form of stress and strain plots. factors of safety for failed elements, buckling loads and modes, deflection prediction tables and plots, and strainage prediction tables and plots. The collected results are presented within this report for comparison to test results.

  8. Optimal Synthesis of the Joint Unitary Evolutions

    NASA Astrophysics Data System (ADS)

    Wei, Hai-Rui; Alsaedi, Ahmed; Hobiny, Aatef; Deng, Fu-Guo; Hu, Hui; Zhang, Dun

    2018-07-01

    Joint unitary operations play a central role in quantum communication and computation. We give a quantum circuit for implementing a type of unconstructed useful joint unitary evolutions in terms of controlled-NOT (CNOT) gates and single-qubit rotations. Our synthesis is optimal and possible in experiment. Two CNOT gates and seven R x , R y or R z rotations are required for our synthesis, and the arbitrary parameter contained in the evolutions can be controlled by local Hamiltonian or external fields.

  9. Optimal Synthesis of the Joint Unitary Evolutions

    NASA Astrophysics Data System (ADS)

    Wei, Hai-Rui; Alsaedi, Ahmed; Hobiny, Aatef; Deng, Fu-Guo; Hu, Hui; Zhang, Dun

    2018-03-01

    Joint unitary operations play a central role in quantum communication and computation. We give a quantum circuit for implementing a type of unconstructed useful joint unitary evolutions in terms of controlled-NOT (CNOT) gates and single-qubit rotations. Our synthesis is optimal and possible in experiment. Two CNOT gates and seven R x , R y or R z rotations are required for our synthesis, and the arbitrary parameter contained in the evolutions can be controlled by local Hamiltonian or external fields.

  10. Robust energy-absorbing compensators for the ACTEX II test article

    NASA Astrophysics Data System (ADS)

    Blaurock, Carl A.; Miller, David W.; Nye, Ted

    1995-05-01

    The paper addresses the problem of satellite solar panel vibration. A multi-layer vibration control scheme is investigated using a flight test article. Key issues in the active control portion are presented in the paper. The paper discusses the primary control design drivers, which are the time variations in modal frequencies due to configuration and thermal changes. A local control design approach is investigated, but found to be unworkable due to sensor/actuator non-collocation. An alternate design process uses linear robust control techniques, by describing the modal shifts as uncertainties. Multiple modal design, alpha- shifted multiple model, and a feedthrough compensation scheme are examined. Ground and simulation tests demonstrate that the resulting controllers provide significant vibration reduction in the presence of expected system variations.

  11. Joint maximum-likelihood magnitudes of presumed underground nuclear test explosions

    NASA Astrophysics Data System (ADS)

    Peacock, Sheila; Douglas, Alan; Bowers, David

    2017-08-01

    Body-wave magnitudes (mb) of 606 seismic disturbances caused by presumed underground nuclear test explosions at specific test sites between 1964 and 1996 have been derived from station amplitudes collected by the International Seismological Centre (ISC), by a joint inversion for mb and station-specific magnitude corrections. A maximum-likelihood method was used to reduce the upward bias of network mean magnitudes caused by data censoring, where arrivals at stations that do not report arrivals are assumed to be hidden by the ambient noise at the time. Threshold noise levels at each station were derived from the ISC amplitudes using the method of Kelly and Lacoss, which fits to the observed magnitude-frequency distribution a Gutenberg-Richter exponential decay truncated at low magnitudes by an error function representing the low-magnitude threshold of the station. The joint maximum-likelihood inversion is applied to arrivals from the sites: Semipalatinsk (Kazakhstan) and Novaya Zemlya, former Soviet Union; Singer (Lop Nor), China; Mururoa and Fangataufa, French Polynesia; and Nevada, USA. At sites where eight or more arrivals could be used to derive magnitudes and station terms for 25 or more explosions (Nevada, Semipalatinsk and Mururoa), the resulting magnitudes and station terms were fixed and a second inversion carried out to derive magnitudes for additional explosions with three or more arrivals. 93 more magnitudes were thus derived. During processing for station thresholds, many stations were rejected for sparsity of data, obvious errors in reported amplitude, or great departure of the reported amplitude-frequency distribution from the expected left-truncated exponential decay. Abrupt changes in monthly mean amplitude at a station apparently coincide with changes in recording equipment and/or analysis method at the station.

  12. Sacroiliac joint motion in patients with degenerative lumbar spine disorders.

    PubMed

    Nagamoto, Yukitaka; Iwasaki, Motoki; Sakaura, Hironobu; Sugiura, Tsuyoshi; Fujimori, Takahito; Matsuo, Yohei; Kashii, Masafumi; Murase, Tsuyoshi; Yoshikawa, Hideki; Sugamoto, Kazuomi

    2015-08-01

    OBJECT Usually additional anchors into the ilium are necessary in long fusion to the sacrum for degenerative lumbar spine disorders (DLSDs), especially for adult spine deformity. Although the use of anchors is becoming quite common, surgeons must always keep in mind that the sacroiliac (SI) joint is mobile and they should be aware of the kinematic properties of the SI joint in patients with DLSDs, including adult spinal deformity. No previous study has clarified in vivo kinematic changes in the SI joint with respect to patient age, sex, or parturition status or the presence of DLSDs. The authors conducted a study to clarify the mobility and kinematic characteristics of the SI joint in patients with DLSDs in comparison with healthy volunteers by using in vivo 3D motion analysis with voxel-based registration, a highly accurate, noninvasive method. METHODS Thirteen healthy volunteers (the control group) and 20 patients with DLSDs (the DLSD group) underwent low-dose 3D CT of the lumbar spine and pelvis in 3 positions (neutral, maximal trunk flexion, and maximal trunk extension). SI joint motion was calculated by computer processing of the CT images (voxel-based registration). 3D motion of the SI joint was expressed as both 6 df by Euler angles and translations on the coordinate system and a helical axis of rotation. The correlation between joint motion and the cross-sectional area of the trunk muscles was also investigated. RESULTS SI joint motion during trunk flexion-extension was minute in healthy volunteers. The mean rotation angles during trunk flexion were 0.07° around the x axis, -0.02° around the y axis, and 0.16° around the z axis. The mean rotation angles during trunk extension were 0.38° around the x axis, -0.08° around the y axis, and 0.08° around the z axis. During trunk flexion-extension, the largest amount of motion occurred around the x axis. In patients with DLSDs, the mean rotation angles during trunk flexion were 0.57° around the x axis, 0.01

  13. Toward a mechanistic understanding of the damage evolution of SnAgCu solder joints in accelerated thermal cycling test

    NASA Astrophysics Data System (ADS)

    Mahin Shirazi, Sam

    Accelerated thermal cycling (ATC) tests are the most commonly used tests for the thermo-mechanical performance assessment of microelectronics assemblies. Currently used reliability models have failed to incorporate the microstructural dependency of lead free solder joint behavior and its microstructure evolution during cycling. Thus, it is essential to have a mechanistic understanding of the effect of cycling parameters on damage evolution and failure of lead free solder joints in ATC. Recrystallization has been identified as the damage rate controlling mechanism in ATC. Usually it takes 1/3 of life for completion of recrystallization regardless of cycling parameters. Thus, the life of the solder joints can be predicted by estimating global recrystallization. The objective of the first part of the study was to examine whether the damage scenario applies in service is the same as the harsh thermal cycling tests (i.e. 0/100 °C and -40/125 °C) commonly used in industry. Microstructure analysis results on a variety of lead free solder SnAgCu assemblies subjected to the both harsh (0/100 °C) and mild (20/80 °C) ATC confirmed similar failure mechanism under the both testing conditions. Sn grain morphology (interlaced versus beach ball) has a significant effect on the thermo-mechanical performance (and thus the model) of the lead free solder joints. The longer thermal cycling lifetime observed in the interlaced solder joints subjected to the ATC compared to the beach ball structure was correlated to the different initial microstructure and the microstructure evolution during cycling. For the modeling proposes, the present study was focused on Sn-Ag-Cu solder joints with either a single Sn grain or beach ball structure. Microstructural analysis results of the simulated thermal cycling experiment revealed that, the life can be approximated as determined by the accumulation of a certain amount of work during the high temperature dwells. Finally the effect of precipitates

  14. Ambulatory surgery center joint ventures involving tax-exempt entities.

    PubMed

    Becker, S; Pristave, R J; McConnell, W

    1999-01-01

    This article provides an overview of the tax-exempt related issues for ambulatory surgery center joint ventures involving tax-exempt entities. The article analyzes the key points of analysis of the guidance released by the IRS, in particular General Counsel Memorandum 39862, Revenue Ruling 98-15, and Redlands Surgical Services v. Commissioner of the Internal Revenue Service. These key points include whether the venture results in private inurement to insiders and whether the venture furthers the charitable purposes of the tax-exempt entity. The article also provides practical guidance to analyze the documents and structure of the joint venture to ensure compliance with the IRS guidance. These practical considerations include, among other things, whether the charitable purposes of the tax-exempt entity are clearly expressed in the documents and whether the tax-exempt entity has sufficient control over the joint venture to ensure the charitable purposes are being adhered to.

  15. Computer simulation of solder joint failure

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Burchett, S.N.; Frear, D.R.; Rashid, M.M.

    The thermomechanical fatigue failure of solder joints is increasingly becoming an important reliability issue for electronic packages. The purpose of this Laboratory Directed Research and Development (LDRD) project was to develop computational tools for simulating the behavior of solder joints under strain and temperature cycling, taking into account the microstructural heterogeneities that exist in as-solidified near eutectic Sn-Pb joints, as well as subsequent microstructural evolution. The authors present two computational constitutive models, a two-phase model and a single-phase model, that were developed to predict the behavior of near eutectic Sn-Pb solder joints under fatigue conditions. Unique metallurgical tests provide themore » fundamental input for the constitutive relations. The two-phase model mathematically predicts the heterogeneous coarsening behavior of near eutectic Sn-Pb solder. The finite element simulations with this model agree qualitatively with experimental thermomechanical fatigue tests. The simulations show that the presence of an initial heterogeneity in the solder microstructure could significantly degrade the fatigue lifetime. The single-phase model was developed to predict solder joint behavior using materials data for constitutive relation constants that could be determined through straightforward metallurgical experiments. Special thermomechanical fatigue tests were developed to give fundamental materials input to the models, and an in situ SEM thermomechanical fatigue test system was developed to characterize microstructural evolution and the mechanical behavior of solder joints during the test. A shear/torsion test sample was developed to impose strain in two different orientations. Materials constants were derived from these tests. The simulation results from the two-phase model showed good fit to the experimental test results.« less

  16. Boeing's CST-100 Structural Test Article Shipment from C3PF to B

    NASA Image and Video Library

    2016-11-22

    Boeing’s Structural Test Article of its CST-100 Starliner spacecraft is moved out of the company’s Commercial Crew and Cargo Processing Facility at NASA’s Kennedy Space Center on its way to Huntington Beach, California, for evaluations. Built to the specifications of an operational spacecraft, the STA is intended to be evaluated through a series of thorough testing conditions.

  17. Toughness characterization by small specimen test technique for HIPed joints of F82H steel aiming at first wall fabrication in fusion

    NASA Astrophysics Data System (ADS)

    Kishimoto, H.; Ono, T.; Sakasegawa, H.; Tanigawa, H.; Kohno, Y.; Kohyama, A.

    2013-09-01

    Reduced activation ferritic/martensitic steels (RAFMs), such as F82H steels, have been developed as candidates of structural materials for fusion. In the design of a fusion reactor, cooling channels are built in the first wall of the blanket. One large issue is to determine how to join rectangular tubes to thin panels to fabricate the first wall. Hot Isostatic Pressing (HIPing) is a solution to solve the issue. Because of the thin HIPed walls of the channels, the specimen size for inspection of HIPed interface is limited. In the present research, Small Specimen Test Techniques (SSTT) are screened for the destructive toughness investigation technique of HIPed F82H joints. 1/3 size Charpy V-notch impact (1/3 CVN) and small punch (SP) tests are employed for the present research. The toughness of the HIPed joints is strongly affected by various surface finishing of specimens treated previous to the HIPing. In the present research, several kinds of HIPed joints were surface finished by different methods and investigated by 1/3 CVN impact test. The HIPed F82H joints had different toughness ranging from 20% to 70% of the toughness of the F82H base metal. The SP test is also available for the investigation of toughness change by the HIPing. The sensitivity of 1/3 CVN impact test against toughness change was better than the SP test, it revealed that the SP test has some limitations.

  18. Effect of Epoxy on Mechanical Property of SAC305 Solder Joint with Various Surface Finishes Under 3-Point Bend Test.

    PubMed

    Jeong, Haksan; Myung, Woo-Ram; Sung, Yong-Gue; Kim, Kyung-Yeol; Jung, Seung-Boo

    2018-09-01

    Microstructures and mechanical property of Sn-3.0Ag-0.5Cu (SAC305) and epoxy Sn-3.0Ag-0.5Cu (epoxy SAC) solder joints were investigated with various surface finishes; organic solderability preservative (OSP), electroless nickel immersion gold (ENIG) and electroless nickel electroless palladium immersion gold (ENEPIG). Bending property of solder joints was evaluated by 3-point bend test method. Microstructure and chemical composition of solder joints was characterized by scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX), respectively. Epoxy did not effect on intermetallic compound (IMC) morphology. Scalloped shaped Cu6Sn5 IMC was observed at OSP surface finish. Chunky-like shaped and needle-like shaped (Ni,Cu)6Sn5 IMC were observed at the solder/ENIG joint and solder/ENEPIG joint, respectively. The bending cycles of SAC305/OSP joint, SAC305/ENIG joints and SAC305/ENEPIG joints were 720, 440 and 481 cycle numbers. The bending cycles of epoxy SAC and three types surface finished solder joints were over 1000 bending cycles. Under OSP surface finish, bending cycles of epoxy SAC solder was approximately 1.5 times higher than those of SAC305 solder joint. Bending cycles of epoxy SAC solder was over twice times higher than those of SAC305 solder with ENIG and ENEPIG surface finishes. The bending property of epoxy solder joint was enhanced due to epoxy fillet held the solder joint.

  19. The High performance of nanocrystalline CVD diamond coated hip joints in wear simulator test.

    PubMed

    Maru, M M; Amaral, M; Rodrigues, S P; Santos, R; Gouvea, C P; Archanjo, B S; Trommer, R M; Oliveira, F J; Silva, R F; Achete, C A

    2015-09-01

    The superior biotribological performance of nanocrystalline diamond (NCD) coatings grown by a chemical vapor deposition (CVD) method was already shown to demonstrate high wear resistance in ball on plate experiments under physiological liquid lubrication. However, tests with a close-to-real approach were missing and this constitutes the aim of the present work. Hip joint wear simulator tests were performed with cups and heads made of silicon nitride coated with NCD of ~10 μm in thickness. Five million testing cycles (Mc) were run, which represent nearly five years of hip joint implant activity in a patient. For the wear analysis, gravimetry, profilometry, scanning electron microscopy and Raman spectroscopy techniques were used. After 0.5 Mc of wear test, truncation of the protruded regions of the NCD film happened as a result of a fine-scale abrasive wear mechanism, evolving to extensive plateau regions and highly polished surface condition (Ra<10nm). Such surface modification took place without any catastrophic features as cracking, grain pullouts or delamination of the coatings. A steady state volumetric wear rate of 0.02 mm(3)/Mc, equivalent to a linear wear of 0.27 μm/Mc favorably compares with the best performance reported in the literature for the fourth generation alumina ceramic (0.05 mm(3)/Mc). Also, squeaking, quite common phenomenon in hard-on-hard systems, was absent in the present all-NCD system. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Method for forming biaxially textured articles by powder metallurgy

    DOEpatents

    Goyal, Amit; Williams, Robert K.; Kroeger, Donald M.

    2002-01-01

    A method of preparing a biaxially textured alloy article comprises the steps of preparing a mixture comprising Ni powder and at least one powder selected from the group consisting of Cr, W, V, Mo, Cu, Al, Ce, YSZ, Y, Rare Earths, (RE), MgO, CeO.sub.2, and Y.sub.2 O.sub.3 ; compacting the mixture, followed by heat treating and rapidly recrystallizing to produce a biaxial texture on the article. In some embodiments the alloy article further comprises electromagnetic or electro-optical devices and possesses superconducting properties.

  1. Statistical inferences with jointly type-II censored samples from two Pareto distributions

    NASA Astrophysics Data System (ADS)

    Abu-Zinadah, Hanaa H.

    2017-08-01

    In the several fields of industries the product comes from more than one production line, which is required to work the comparative life tests. This problem requires sampling of the different production lines, then the joint censoring scheme is appeared. In this article we consider the life time Pareto distribution with jointly type-II censoring scheme. The maximum likelihood estimators (MLE) and the corresponding approximate confidence intervals as well as the bootstrap confidence intervals of the model parameters are obtained. Also Bayesian point and credible intervals of the model parameters are presented. The life time data set is analyzed for illustrative purposes. Monte Carlo results from simulation studies are presented to assess the performance of our proposed method.

  2. SLS INTERTANK TEST ARTICLE IS ATTACHED TO CROSSHEAD OF LOAD TEST ANNEX, BLDG. 4619, AND REMOVED FROM BED OF KMAG TRANSPORTER

    NASA Image and Video Library

    2018-03-28

    SLS INTERTANK TEST ARTICLE IS ATTACHED TO CROSSHEAD OF LOAD TEST ANNEX, BLDG. 4619, AND REMOVED FROM BED OF KMAG TRANSPORTER. Matt Cash conducts tag up meeting before lift of ITA from KMAG transporter

  3. Radio-Astronomical Instruments Observations (Selected Articles),

    DTIC Science & Technology

    1982-08-02

    NL SIIDAUG 82 L I MATVEYENKO, G S MISEZHNIKOV UNCLASSIFIED FTO_ ID(RS) -0564-82 N FTD-ID(RS) T -0564-82 FOREIGN TECHNOLOGY DIVISION RADIO-ASTRONOMICAL...INSTR1ThMNTS OBSERVATIONS (Selected Articles) 3 71982 Approved for public release; LAJ distribuion~ urJA’nited. • I . FTD- ID(RS) T -0564-82 UNEDITED... T , t * r a yy y y 7, u F, f E # Ye, ye; E, e* X x X x Kh, kh X C Zh, zn .4 u L q Ts, ts - -. Z ,. 4 f 14 Ch ,ch U 7 H u I , i w Sh, sh 2 R ia Y, y

  4. Nonlinear Modeling of Joint Dominated Structures

    NASA Technical Reports Server (NTRS)

    Chapman, J. M.

    1990-01-01

    The development and verification of an accurate structural model of the nonlinear joint-dominated NASA Langley Mini-Mast truss are described. The approach is to characterize the structural behavior of the Mini-Mast joints and struts using a test configuration that can directly measure the struts' overall stiffness and damping properties, incorporate this data into the structural model using the residual force technique, and then compare the predicted response with empirical data taken by NASA/LaRC during the modal survey tests of the Mini-Mast. A new testing technique, referred to as 'link' testing, was developed and used to test prototype struts of the Mini-Masts. Appreciable nonlinearities including the free-play and hysteresis were demonstrated. Since static and dynamic tests performed on the Mini-Mast also exhibited behavior consistent with joints having free-play and hysteresis, nonlinear models of the Mini-Mast were constructed and analyzed. The Residual Force Technique was used to analyze the nonlinear model of the Mini-Mast having joint free-play and hysteresis.

  5. Experimental Investigation of Composite Pressure Vessel Performance and Joint Stiffness for Pyramid and Inverted Pyramid Joints

    NASA Technical Reports Server (NTRS)

    Verhage, Joseph M.; Bower, Mark V.; Gilbert, Paul A. (Technical Monitor)

    2001-01-01

    The focus of this study is on the suitability in the application of classical laminate theory analysis tools for filament wound pressure vessels with adhesive laminated joints in particular: pressure vessel wall performance, joint stiffness and failure prediction. Two 18-inch diameter 12-ply filament wound pressure vessels were fabricated. One vessel was fabricated with a 24-ply pyramid laminated adhesive double strap butt joint. The second vessel was fabricated with the same number of plies in an inverted pyramid joint. Results from hydrostatic tests are presented. Experimental results were used as input to the computer programs GENLAM and Laminate, and the output compared to test. By using the axial stress resultant, the classical laminate theory results show a correlation within 1% to the experimental results in predicting the pressure vessel wall pressure performance. The prediction of joint stiffness for the two adhesive joints in the axial direction is within 1% of the experimental results. The calculated hoop direction joint stress resultant is 25% less than the measured resultant for both joint configurations. A correction factor is derived and used in the joint analysis. The correction factor is derived from the hoop stress resultant from the tank wall performance investigation. The vessel with the pyramid joint is determined to have failed in the joint area at a hydrostatic pressure 33% value below predicted failure. The vessel with the inverted pyramid joint failed in the wall acreage at a hydrostatic pressure within 10% of the actual failure pressure.

  6. Evaluation of cloud detection instruments and performance of laminar-flow leading-edge test articles during NASA Leading-Edge Flight-Test Program

    NASA Technical Reports Server (NTRS)

    Davis, Richard E.; Maddalon, Dal V.; Wagner, Richard D.; Fisher, David F.; Young, Ronald

    1989-01-01

    Summary evaluations of the performance of laminar-flow control (LFC) leading edge test articles on a NASA JetStar aircraft are presented. Statistics, presented for the test articles' performance in haze and cloud situations, as well as in clear air, show a significant effect of cloud particle concentrations on the extent of laminar flow. The cloud particle environment was monitored by two instruments, a cloud particle spectrometer (Knollenberg probe) and a charging patch. Both instruments are evaluated as diagnostic aids for avoiding laminar-flow detrimental particle concentrations in future LFC aircraft operations. The data base covers 19 flights in the simulated airline service phase of the NASA Leading-Edge Flight-Test (LEFT) Program.

  7. Effect of Nd:YAG laser beam welding on weld morphology and mechanical properties of Ti-6Al-4V butt joints and T-joints

    NASA Astrophysics Data System (ADS)

    Kashaev, Nikolai; Ventzke, Volker; Fomichev, Vadim; Fomin, Fedor; Riekehr, Stefan

    2016-11-01

    A Nd:YAG single-sided laser beam welding process study for Ti-6Al-4V butt joints and T-joints was performed to investigate joining techniques with regard to the process-weld morphology relationship. An alloy compatible filler wire was used to avoid underfills and undercuts. The quality of the butt joints and T-joints was characterized in terms of weld morphology, microstructure and mechanical properties. Joints with regular shapes, without visible cracks, pores, and geometrical defects were achieved. Tensile tests revealed high joint integrity in terms of strength and ductility for both the butt joint and T-joint geometries. Both the butt joints and T-joints showed base material levels of strength. The mechanical performance of T-joints was also investigated using pull-out tests. The performance of the T-joints in such tests was sensitive to the shape and morphology of the welds. Fracture always occurred in the weld without any plastic deformation in the base material outside the weld.

  8. The efficacy of manual joint mobilisation/manipulation in treatment of lateral ankle sprains: a systematic review.

    PubMed

    Loudon, Janice K; Reiman, Michael P; Sylvain, Jonathan

    2014-03-01

    Lateral ankle sprains are common and can have detrimental consequences to the athlete. Joint mobilisation/manipulation may limit these outcomes. Systematically summarise the effectiveness of manual joint techniques in treatment of lateral ankle sprains. This review employed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A computer-assisted literature search of MEDLINE, CINHAL, EMBASE, OVID and Physiotherapy Evidence Database (PEDro) (January 1966 to March 2013) was used with the following keywords alone and in combination 'ankle', 'sprain', 'injuries', 'lateral', 'manual therapy', and 'joint mobilisation'. The methodological quality of individual studies was assessed using the PEDro scale. After screening of titles, abstracts and full articles, eight articles were kept for examination. Three articles achieved a score of 10 of 11 total points; one achieved a score of 9; two articles scored 8; one article scored a 7 and the remaining article scored a 5. Three articles examined joint techniques for acute sprains and the remainder examined subacute/chronic ankle sprains. Outcome measures included were pain level, ankle range of motion, swelling, functional score, stabilometry and gait parameters. The majority of the articles only assessed these outcome measures immediately after treatment. No detrimental effects from the joint techniques were revealed in any of the studies reviewed. For acute ankle sprains, manual joint mobilisation diminished pain and increased dorsiflexion range of motion. For treatment of subacute/chronic lateral ankle sprains, these techniques improved ankle range-of-motion, decreased pain and improved function.

  9. A Survey of Methods for Measuring Thermally Induced Distortions of Test Articles Undergoing Solar Thermal Vacuum Test

    NASA Technical Reports Server (NTRS)

    Rempt, R. D.

    1982-01-01

    Various methods of measuring the small thermally induced distortions experienced either by various points on the space vehicles or by deviations of surfaces from a known shape during solar thermal vacuum tests are examined. State-of-the-art application of both photographic and real time observation are discussed. The relative merits of each of the methods are compared and evaluated in their applications to different types of test articles and situations. Magnitudes of thermally induced distortions which may be expected to be routinely measurable by the various methods are presented and compared.

  10. Test results for composite specimens and elements containing joints and cutouts

    NASA Technical Reports Server (NTRS)

    Sumida, P. T.; Madan, R. C.; Hawley, A. V.

    1988-01-01

    A program was conducted to develop the technology for joints and cutouts in a composite fuselage that meets all design requirements of a large transport aircraft for the 1990s. An advanced trijet derivative of the DC-10 was selected as the baseline aircraft. Design and analysis of a 30-foot-long composite fuselage barrel provided a realistic basis for the test effort. The primary composite material was Hexcel F584 resin on 12 K IM6 fiber, in tape and broadgoods form. Fiberglass broadgoods were used in E-glass and S-glass fiber form in the cutout region of some panels. Additionally, injection-molded chopped graphite fiber/PEEK was used for longeron-to-frame shear clips. The test effort included four groups of test specimens, beginning with coupon specimens of mono-layer and cross-piled laminates, progressing through increasingly larger and more complex specimens, and ending with two 4- by 5-foot curved fuselage side panels. One of the side panels incorporated a transverse skin splice, while the second included two cabin window cutouts.

  11. Phenotypic alterations of neuropeptide Y and calcitonin gene-related peptide-containing neurons innervating the rat temporomandibular joint during carrageenan-induced arthritis

    PubMed Central

    Damico, J.P.; Ervolino, E.; Torres, K.R.; Batagello, D.S.; Cruz-Rizzolo, R.J.; Casatti, C.A.; Bauer, J.A.

    2012-01-01

    The aim of this study was to identify immunoreactive neuropeptide Y (NPY) and calcitonin gene-related peptide (CGRP) neurons in the autonomic and sensory ganglia, specifically neurons that innervate the rat temporomandibular joint (TMJ). A possible variation between the percentages of these neurons in acute and chronic phases of carrageenan-induced arthritis was examined. Retrograde neuronal tracing was combined with indirect immunofluorescence to identify NPY-immunoreactive (NPY-IR) and CGRP- immunoreactive (CGRP-IR) neurons that send nerve fibers to the normal and arthritic temporomandibular joint. In normal joints, NPY-IR neurons constitute 78±3%, 77±6% and 10±4% of double-labeled nucleated neuronal profile originated from the superior cervical, stellate and otic ganglia, respectively. These percentages in the sympathetic ganglia were significantly decreased in acute (58±2% for superior cervical ganglion and 58±8% for stellate ganglion) and chronic (60±2% for superior cervical ganglion and 59±15% for stellate ganglion) phases of arthritis, while in the otic ganglion these percentages were significantly increased to 19±5% and 13±3%, respectively. In the trigeminal ganglion, CGRP-IR neurons innervating the joint significantly increased from 31±3% in normal animals to 54±2% and 49±3% in the acute and chronic phases of arthritis, respectively. It can be concluded that NPY neurons that send nerve fibers to the rat temporomandibular joint are located mainly in the superior cervical, stellate and otic ganglia. Acute and chronic phases of carrageenan-induced arthritis lead to an increase in the percentage of NPY-IR parasympathetic and CGRP-IR sensory neurons and to a decrease in the percentage of NPY-IR sympathetic neurons related to TMJ innervation. PMID:23027347

  12. Comparison of Modal Analysis Methods Applied to a Vibro-Acoustic Test Article

    NASA Technical Reports Server (NTRS)

    Pritchard, Jocelyn; Pappa, Richard; Buehrle, Ralph; Grosveld, Ferdinand

    2001-01-01

    Modal testing of a vibro-acoustic test article referred to as the Aluminum Testbed Cylinder (ATC) has provided frequency response data for the development of validated numerical models of complex structures for interior noise prediction and control. The ATC is an all aluminum, ring and stringer stiffened cylinder, 12 feet in length and 4 feet in diameter. The cylinder was designed to represent typical aircraft construction. Modal tests were conducted for several different configurations of the cylinder assembly under ambient and pressurized conditions. The purpose of this paper is to present results from dynamic testing of different ATC configurations using two modal analysis software methods: Eigensystem Realization Algorithm (ERA) and MTS IDEAS Polyreference method. The paper compares results from the two analysis methods as well as the results from various test configurations. The effects of pressurization on the modal characteristics are discussed.

  13. Stochastic joint inversion of hydrogeophysical data for salt tracer test monitoring and hydraulic conductivity imaging

    NASA Astrophysics Data System (ADS)

    Jardani, A.; Revil, A.; Dupont, J. P.

    2013-02-01

    The assessment of hydraulic conductivity of heterogeneous aquifers is a difficult task using traditional hydrogeological methods (e.g., steady state or transient pumping tests) due to their low spatial resolution. Geophysical measurements performed at the ground surface and in boreholes provide additional information for increasing the resolution and accuracy of the inverted hydraulic conductivity field. We used a stochastic joint inversion of Direct Current (DC) resistivity and self-potential (SP) data plus in situ measurement of the salinity in a downstream well during a synthetic salt tracer experiment to reconstruct the hydraulic conductivity field between two wells. The pilot point parameterization was used to avoid over-parameterization of the inverse problem. Bounds on the model parameters were used to promote a consistent Markov chain Monte Carlo sampling of the model parameters. To evaluate the effectiveness of the joint inversion process, we compared eight cases in which the geophysical data are coupled or not to the in situ sampling of the salinity to map the hydraulic conductivity. We first tested the effectiveness of the inversion of each type of data alone (concentration sampling, self-potential, and DC resistivity), and then we combined the data two by two. We finally combined all the data together to show the value of each type of geophysical data in the joint inversion process because of their different sensitivity map. We also investigated a case in which the data were contaminated with noise and the variogram unknown and inverted stochastically. The results of the inversion revealed that incorporating the self-potential data improves the estimate of hydraulic conductivity field especially when the self-potential data were combined to the salt concentration measurement in the second well or to the time-lapse cross-well electrical resistivity data. Various tests were also performed to quantify the uncertainty in the inverted hydraulic conductivity

  14. Evaluation of pipe-type cable joint restraint systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Silver, D.A.; Seman, G.W.

    1990-03-01

    the purpose of this project was to evaluate two systems for restraining the movement of 345kV high-pressure oil-filled (HPOF) cable joints during load cycling. Problems with joints and adjacent cables due to thermomechanical bending (TMB) experienced by the Consolidated Edison Company of New York and Public Service Electric Gas Company of New Jersey are reviewed. Some approaches to reducing or preventing TMB induced damage to HPOF pipe type cable joints are discussed. The design and operation of a special test apparatus for simulating TMB effects under laboratory conditions is described. One of the two joint restraint systems evaluated under thismore » project was developed by PSE G and employed wedging devices, which could be retrofitted into existing installations, that limited the longitudinal movement of the joints during load cycling. The other system developed by Pirelli Cable Corporation applied the restraining force to the cylindrical portion of the hand applied joint insulation by means of support spiders and steel rods attached to the reducer faces. The test results show that the PSE G restraint system can effectively limit joint longitudinal movement while causing a minimal amount of mechanical disturbance to the joint stress cones. The test results obtained with the PCC system are inconclusive and indicate that further refinement and testing are required to demonstrate the effectiveness of this promising joint restraint system.« less

  15. 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.

  16. Diagnosis of prosthetic joint infection with alpha-defensin using a lateral flow device: a multicentre study.

    PubMed

    Berger, P; Van Cauter, M; Driesen, R; Neyt, J; Cornu, O; Bellemans, J

    2017-09-01

    The purpose of this current multicentre study is to analyse the presence of alpha-defensin proteins in synovial fluid using the Synovasure lateral flow device and to determine its diagnostic reliability and accuracy compared with the prosthetic joint infection (PJI) criteria produced by the Musculoskeletal Infection Society (MSIS). A cohort of 121 patients comprising 85 total knee arthroplasties and 36 total hip arthroplasties was prospectively evaluated between May 2015 and June 2016 in three different orthopaedic centres. The tests were performed on patients with a chronically painful prosthesis undergoing a joint aspiration in a diagnostic pathway or during revision surgery. Based on the MSIS criteria, 34 patients (28%) would have had a PJI, and 87 patients had no PJI. Testing with the lateral flow device had a sensitivity of 97.1% (95% confidence intervals (CI) 84.5 to 99.9) and a specificity of 96.6% (95% CI 90.3 to 99.2). The positive predictive value was 91.7% (95% CI 77.7% to 98.3), and the negative predictive value was 98.8% (95% CI 93.6 to 99.9). Receiver operator characteristics analysis demonstrated an area under the curve for the Synovasure test of 0.97 (95% CI 0.93 to 1.00). Our findings suggest that the Synovasure test has an excellent diagnostic performance to confirm or reject the diagnosis of a PJI. The results are promising for the care of the painful or problematic knee and hip joint arthroplasty and the test should be considered as part of the diagnostic toolbox for PJIs. Cite this article: Bone Joint J 2017;99-B:1176-82. ©2017 The British Editorial Society of Bone & Joint Surgery.

  17. Flat H Frangible Joint Evolution

    NASA Technical Reports Server (NTRS)

    Diegelman, Thomas E.; Hinkel, Todd J.; Benjamin, Andrew; Rochon, Brian V.; Brown, Christopher W.

    2016-01-01

    Space vehicle staging and separation events require pyrotechnic devices. They are single-use mechanisms that cannot be tested, nor can failure-tolerant performance be demonstrated in actual flight articles prior to flight use. This necessitates the implementation of a robust design and test approach coupled with a fully redundant, failure-tolerant explosive mechanism to ensure that the system functions even in the event of a single failure. Historically, NASA has followed the single failure-tolerant (SFT) design philosophy for all human-rated spacecraft, including the Space Shuttle Program. Following the end of this program, aerospace companies proposed building the next generation human-rated vehicles with off-the-shelf, non-redundant, zero-failure-tolerant (ZFT) separation systems. Currently, spacecraft and launch vehicle providers for both the Orion and Commercial Crew Programs (CCPs) plan to deviate from the heritage safety approach and NASA's SFT human rating requirements. Both programs' partners have base-lined ZFT frangible joints for vehicle staging and fairing separation. These joints are commercially available from pyrotechnic vendors. Non-human-rated missions have flown them numerous times. The joints are relatively easy to integrate structurally within the spacecraft. In addition, the separation event is debris free, and the resultant pyro shock is lower than that of other design solutions. It is, however, a serious deficiency to lack failure tolerance. When used for critical applications on human-rated vehicles, a single failure could potentially lead to loss of crew (LOC) or loss of mission (LOM)). The Engineering and Safety & Mission Assurance directorates within the NASA Johnson Space Center took action to address this safety issue by initiating a project to develop a fully redundant, SFT frangible joint design, known as the Flat H. Critical to the ability to retrofit on launch vehicles being developed, the SFT mechanisms must fit within the same

  18. Flaw Tolerance in Lap Shear Brazed Joints. Part 1

    NASA Technical Reports Server (NTRS)

    Flom, Yury; Wang, Li-Qin

    2003-01-01

    Furnace brazing is a joining process used in the aerospace and other industries to produce strong permanent and hermetic structural joints. As in any joining process, brazed joints have various imperfections and defects. At the present time, our understanding of the influence of the internal defects on the strength of the brazed joints is not adequate. The goal of this 3-part investigation is to better understand the properties and failure mechanisms of the brazed joints containing defects. This study focuses on the behavior of the brazed lap shear joints because of their importance in manufacturing aerospace structures. In Part 1, an average shear strength capability and failure modes of the single lap joints are explored. Stainless steel specimens brazed with pure silver are tested in accordance with the AWS C3.2 standard. Comparison of the failure loads and the ultimate shear strength with the Finite Element Analysis (FEA) of the same specimens as a function of the overlap widths shows excellent correlation between the experimental and calculated values for the defect-free lap joints. A damage zone criterion is shown to work quite well in understanding the failure of the braze joints. In Part 2, the findings of the Part 1 will be verified on the larger test specimens. Also, various flaws will be introduced in the test specimens to simulate lack of braze coverage in the lap joints. Mechanical testing and FEA will be performed on these joints to verify that behavior of the flawed ductile lap joints is similar to joints with a reduced braze area. Finally, in Part 3, the results obtained in Parts 1 and 2 will be applied to the actual brazed structure to evaluate the load-carrying capability of a structural lap joint containing discontinuities. In addition, a simplified engineering procedure will be offered for the laboratory testing of the lap shear specimens.

  19. Provocation testing to assist craniomandibular pain diagnosis.

    PubMed

    DuPont, John S; Brown, Christopher E

    2010-04-01

    Patients with TMD often present with complex pain symptoms, which can make it difficult to reach a diagnosis. Usually palpation of the masticatory muscles and TM joints, range of motion testing and imaging are used in the diagnostic process. Sometimes it is necessary to evaluate the jaw moving muscles from a functional prospective because they cannot be palpated due to inaccessibility or because they have other structures that are more superficial to them. In these instances, provocation testing can be a helpful adjunct in providing some insight into what is occurring in the area being tested and localizing a suspected source of pain. Anesthesia blocking can be used to confirm any positive findings. This article explores several provocation tests that can be used to evaluate conditions of the masticatory musculature, the TM joints and the stylomandibular ligament.

  20. Novel Ultrasound Joint Selection Methods Using a Reduced Joint Number Demonstrate Inflammatory Improvement when Compared to Existing Methods and Disease Activity Score at 28 Joints.

    PubMed

    Tan, York Kiat; Allen, John C; Lye, Weng Kit; Conaghan, Philip G; D'Agostino, Maria Antonietta; Chew, Li-Ching; Thumboo, Julian

    2016-01-01

    A pilot study testing novel ultrasound (US) joint-selection methods in rheumatoid arthritis. Responsiveness of novel [individualized US (IUS) and individualized composite US (ICUS)] methods were compared with existing US methods and the Disease Activity Score at 28 joints (DAS28) for 12 patients followed for 3 months. IUS selected up to 7 and 12 most ultrasonographically inflamed joints, while ICUS additionally incorporated clinically symptomatic joints. The existing, IUS, and ICUS methods' standardized response means were -0.39, -1.08, and -1.11, respectively, for 7 joints; -0.49, -1.00, and -1.16, respectively, for 12 joints; and -0.94 for DAS28. Novel methods effectively demonstrate inflammatory improvement when compared with existing methods and DAS28.

  1. Joint Denoising/Compression of Image Contours via Shape Prior and Context Tree

    NASA Astrophysics Data System (ADS)

    Zheng, Amin; Cheung, Gene; Florencio, Dinei

    2018-07-01

    With the advent of depth sensing technologies, the extraction of object contours in images---a common and important pre-processing step for later higher-level computer vision tasks like object detection and human action recognition---has become easier. However, acquisition noise in captured depth images means that detected contours suffer from unavoidable errors. In this paper, we propose to jointly denoise and compress detected contours in an image for bandwidth-constrained transmission to a client, who can then carry out aforementioned application-specific tasks using the decoded contours as input. We first prove theoretically that in general a joint denoising / compression approach can outperform a separate two-stage approach that first denoises then encodes contours lossily. Adopting a joint approach, we first propose a burst error model that models typical errors encountered in an observed string y of directional edges. We then formulate a rate-constrained maximum a posteriori (MAP) problem that trades off the posterior probability p(x'|y) of an estimated string x' given y with its code rate R(x'). We design a dynamic programming (DP) algorithm that solves the posed problem optimally, and propose a compact context representation called total suffix tree (TST) that can reduce complexity of the algorithm dramatically. Experimental results show that our joint denoising / compression scheme outperformed a competing separate scheme in rate-distortion performance noticeably.

  2. Managed care and critical pathway development: the joint replacement experience.

    PubMed

    Benham, A J

    1999-01-01

    This article examines the economic, social, ethical, and political issues affecting total joint replacement patients in a managed care environment. Using general systems theory as a framework, it examines the interrelated historical events that have shaped the development of both joint replacement procedures and managed care, and discusses the extent to which these two phenomena have been mutually influential. Specifically, the article examines the initial development, implementation, and continuing evolution of clinical pathways as an easily identified and relatively discrete manifestation of managed care for the joint replacement population. While the overall impact of managed care is beyond the scope of this presentation, it is hoped that a focus on the practical application of clinical pathways to joint replacement will allow some general principles to emerge that may be useful for both patients and practitioners operating in other aspects of the managed care environment.

  3. The Analysis of Adhesively Bonded Advanced Composite Joints Using Joint Finite Elements

    NASA Technical Reports Server (NTRS)

    Stapleton, Scott E.; Waas, Anthony M.

    2012-01-01

    The design and sizing of adhesively bonded joints has always been a major bottleneck in the design of composite vehicles. Dense finite element (FE) meshes are required to capture the full behavior of a joint numerically, but these dense meshes are impractical in vehicle-scale models where a course mesh is more desirable to make quick assessments and comparisons of different joint geometries. Analytical models are often helpful in sizing, but difficulties arise in coupling these models with full-vehicle FE models. Therefore, a joint FE was created which can be used within structural FE models to make quick assessments of bonded composite joints. The shape functions of the joint FE were found by solving the governing equations for a structural model for a joint. By analytically determining the shape functions of the joint FE, the complex joint behavior can be captured with very few elements. This joint FE was modified and used to consider adhesives with functionally graded material properties to reduce the peel stress concentrations located near adherend discontinuities. Several practical concerns impede the actual use of such adhesives. These include increased manufacturing complications, alterations to the grading due to adhesive flow during manufacturing, and whether changing the loading conditions significantly impact the effectiveness of the grading. An analytical study is conducted to address these three concerns. Furthermore, proof-of-concept testing is conducted to show the potential advantages of functionally graded adhesives. In this study, grading is achieved by strategically placing glass beads within the adhesive layer at different densities along the joint. Furthermore, the capability to model non-linear adhesive constitutive behavior with large rotations was developed, and progressive failure of the adhesive was modeled by re-meshing the joint as the adhesive fails. Results predicted using the joint FE was compared with experimental results for various

  4. Evaluation of three force-position hybrid control methods for a robot-based biological joint-testing system.

    PubMed

    Hsieh, Hong-Jung; Hu, Chih-Chung; Lu, Tung-Wu; Lu, Hsuan-Lun; Kuo, Mei-Ying; Kuo, Chien-Chung; Hsu, Horng-Chaung

    2016-06-07

    Robot-based joint-testing systems (RJTS) can be used to perform unconstrained laxity tests, measuring the stiffness of a degree of freedom (DOF) of the joint at a fixed flexion angle while allowing the other DOFs unconstrained movement. Previous studies using the force-position hybrid (FPH) control method proposed by Fujie et al. (J Biomech Eng 115(3):211-7, 1993) focused on anterior/posterior tests. Its convergence and applicability on other clinically relevant DOFs such as valgus/varus have not been demonstrated. The current s1tudy aimed to develop a 6-DOF RJTS using an industrial robot, to propose two new force-position hybrid control methods, and to evaluate the performance of the methods and FPH in controlling the RJTS for anterior/posterior and valgus/varus laxity tests of the knee joint. An RJTS was developed using an industrial 6-DOF robot with a 6-component load-cell attached at the effector. The performances of FPH and two new control methods, namely force-position alternate control (FPA) and force-position hybrid control with force-moment control (FPHFM), for unconstrained anterior/posterior and valgus/varus laxity tests were evaluated and compared with traditional constrained tests (CT) in terms of the number of control iterations, total time and the constraining forces and moments. As opposed to CT, the other three control methods successfully reduced the constraining forces and moments for both anterior/posterior and valgus/varus tests, FPHFM being the best followed in order by FPA and FPH. FPHFM had root-mean-squared constraining forces and moments of less than 2.2 N and 0.09 Nm, respectively at 0° flexion, and 2.3 N and 0.14 Nm at 30° flexion. The corresponding values for FPH were 8.5 N and 0.33 Nm, and 11.5 N and 0.45 Nm, respectively. Given the same control parameters including the compliance matrix, FPHFM and FPA reduced the constraining loads of FPH at the expense of additional control iterations, and thus increased total time, FPA

  5. Temporomandibular joint dislocation

    PubMed Central

    Sharma, Naresh Kumar; Singh, Akhilesh Kumar; Pandey, Arun; Verma, Vishal; Singh, Shreya

    2015-01-01

    Temporomandibular joint (TMJ) dislocation is an uncommon but debilitating condition of the facial skeleton. The condition may be acute or chronic. Acute TMJ dislocation is common in clinical practice and can be managed easily with manual reduction. Chronic recurrent TMJ dislocation is a challenging situation to manage. In this article, we discuss the comprehensive review of the different treatment modalities in managing TMJ dislocation. PMID:26668447

  6. Test-retest reliability of a new device for assessing ankle joint threshold to detect passive movement in healthy adults.

    PubMed

    Sun, Wei; Song, Qipeng; Yu, Bing; Zhang, Cui; Mao, Dewei

    2015-01-01

    This study aimed to evaluate the test-retest reliability of a new device for assessing ankle joint kinesthesia. This device could measure the passive motion threshold of four ankle joint movements, namely plantarflexion, dorsiflexion, inversion and eversion. A total of 21 healthy adults, including 13 males and 8 females, participated in the study. Each participant completed two sessions on two separate days with 1-week interval. The sessions were administered by the same experimenter in the same laboratory. At least 12 trials (three successful trials in each of the four directions) were performed in each session. The mean values in each direction were calculated and analysed. The ICC values of test-retest reliability ranged from 0.737 (dorsiflexion) to 0.935 (eversion), whereas the SEM values ranged from 0.21° (plantarflexion) to 0.52° (inversion). The Bland-Altman plots showed that the reliability of plantarflexion-dorsiflexion was better than that of inversion-eversion. The results evaluated the reliability of the new device as fair to excellent. The new device for assessing kinesthesia could be used to examine the ankle joint kinesthesia.

  7. [Carpus and distal radioulnar joint : Clinical and radiological examination].

    PubMed

    Spies, C K; Langer, M F; Unglaub, F; Mühldorfer-Fodor, M; Müller, L P; Ahrens, C; Schlindwein, S F

    2016-08-01

    A precise medical history and specific symptom-oriented clinical tests of the wrist joint should always precede any radiological, computed tomography (CT) or magnetic resonance imaging (MRI) diagnostics. In many cases, specific clinical tests of the wrist joint allow at least a preliminary diagnosis, which can be supported by standard radiography using correct projections. A systematic approach is recommended covering the radiocarpal, midcarpal, ulnocarpal and distal radioulnar joints. Exact identification of the palpable anatomic landmarks is mandatory for correct application and interpretation of the various clinical tests. The results of the clinical tests in combination with radiological imaging can often detect precisely ruptures of distinct wrist joint ligaments and localized arthritis.

  8. Leak test fixture and method for using same

    DOEpatents

    Hawk, Lawrence S.

    1976-01-01

    A method and apparatus are provided which are especially useful for leak testing seams such as an end closure or joint in an article. The test does not require an enclosed pressurized volume within the article or joint section to be leak checked. A flexible impervious membrane is disposed over an area of the seamed surfaces to be leak checked and sealed around the outer edges. A preselected vacuum is applied through an opening in the membrane to evacuate the area between the membrane and the surface being leak checked to essentially collapse the membrane to conform to the article surface or joined adjacent surfaces. A pressure differential is concentrated at the seam bounded by the membrane and only the seam experiences a pressure differential as air or helium molecules are drawn into the vacuum system through a leak in the seam. A helium detector may be placed in a vacuum exhaust line from the membrane to detect the helium. Alternatively, the vacuum system may be isolated at a preselected pressure and leaks may be detected by a subsequent pressure increase in the vacuum system.

  9. Association between composites of selected motion palpation and pain provocation tests for sacroiliac joint disorders.

    PubMed

    Soleimanifar, Manijeh; Karimi, Noureddin; Arab, Amir Massoud

    2017-04-01

    The sacroiliac joint (SIJ) has been implicated as a potential source of low back and buttock pain. Several types of motion palpation and pain provocation tests are used to evaluate SIJ dysfunction. The purpose of this study was to investigate the relationship between motion palpation and pain provocation tests in assessment of SIJ problems. This study is Descriptive Correlation. 50 patients between the ages of 20 and 65 participated. Four motion palpation tests (Sitting flexion, Standing flexion, Prone knee flexion, Gillet test) and three pain provocation tests (FABER, Posterior shear, Resisted abduction test) were examined. Chi-square analysis was used to assess the relationship between results of the individuals and composites of these two groups of tests. No significant relationship was found between these two groups of tests. It seems that motion palpation tests assess SIJ dysfunction and provocative tests assessed SIJ pain which do not appear to be related. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Effect of Boundary Condition on the Shear Behaviour of Rock Joints in the Direct Shear Test

    NASA Astrophysics Data System (ADS)

    Bahaaddini, M.

    2017-05-01

    The common method for determination of the mechanical properties of the rock joints is the direct shear test. This paper aims to study the effect of boundary condition on the results of direct shear tests. Experimental studies undertaken in this research showed that the peak shear strength is mostly overestimated. This problem is more pronounced for steep asperities and under high normal stresses. Investigation of the failure mode of these samples showed that tensile cracks are generated at the boundary of sample close to the specimen holders and propagated inside the intact materials. In order to discover the reason of observed failure mechanism in experiments, the direct shear test was simulated using PFC2D. Results of numerical models showed that the gap zone size between the upper and lower specimen holders has a significant effect on the shear mechanism. For the high gap size, stresses concentrate at the vicinity of the tips of specimen holders and result in generation and propagation of tensile cracks inside the intact material. However, by reducing the gap size, stresses are concentrated on asperities, and damage of specimen at its boundary is not observed. Results of this paper show that understanding the shear mechanism of rock joints is an essential step prior to interpreting the results of direct shear tests.

  11. Pros and cons of the ambulatory surgery center joint venture.

    PubMed

    Giannini, Deborah

    2008-01-01

    If a physician group has determined that it has a realistic patient base to establish an ambulatory surgery center, it may be beneficial to consider a partner to share the costs and risks of this new joint venture. Joint ventures can be a benefit or liability in the establishment of an ambulatory surgery center. This article discusses the advantages and disadvantages of a hospital physician-group joint venture.

  12. Measurement of groove features and dimensions of the vertical test cathode and the choke joint of the superconducting electron gun cavity of the Energy Recovery LINAC

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hammons, L.; Ke, M.

    2011-10-13

    with the vertical test cathode, the geometry of these grooves was altered, presenting the possibility that multipacting may, in fact, be occurring in this area and contributing to the low gradients that have been observed in the fine-grain cavity. Therefore, the Survey and Alignment group in C-AD engaged in measurements of the cavity joint, shown in Figure 2 and the cathode weldment, shown in Figure 3 for the purpose of characterizing the grooves in both the cavity and the vertical test cathode and comparing the dimensions of the cathode with those of the prints supplied by Advanced Energy Systems (AES), the original designer and manufacturer of both the test cathode and the electron gun cavity, in preparation to have a new one manufactured. The goal was to ensure that the articles as built matched the design prints in preparation for manufacturing a new vertical test cathode. This report describes the data collected by the Survey group in these efforts. The endeavor was challenging for the group given the millimeter-scale dimensions of the grooves and the requirement for high precision.« less

  13. Aspects of the structural evolution of lead-free solder joints

    NASA Astrophysics Data System (ADS)

    Zribi, A.; Kinyanjui, R.; Borgesen, P.; Zavalij, L.; Cotts, E. J.

    2002-06-01

    Studies of the formation of intermetallic compounds at some lead-free solder/metallization interfaces are briefly reviewed in this article. SnAgCu/Ni and SnAgCu/Cu interfaces are examined in particular. It has been found that (Cu,Ni)6Sn5 forms at SnAgCu/Ni interfaces until copper is depleted from the solder matrix. This article also contrasts the formation of (Au,Ni)Sn4 and related compounds in PbSn/Ni solder joints and lead-free solder joints.

  14. Nikolaus Rüdinger (1832-1896), His Description of Joint Innervation in 1857, and the History of Surgical Joint Denervation.

    PubMed

    Gohritz, Andreas; Kaiser, Erich; Guggenheim, Merlin; Dellon, Arnold Lee

    2018-01-01

     Selective joint denervation has become a reliable palliative treatment, especially for painful joints in the upper and lower extremity.  This article highlights the life and work of Nikolaus Rüdinger (1832-1896) who first described joint innervation which became the basis of later techniques of surgical joint denervation. The historical evolution of this method is outlined.  Rüdinger made a unique career from apprentice barber to military surgeon and anatomy professor in Munich, Germany. His first description of articular innervation of temporomandibular, shoulder, elbow, wrist, finger, sacroiliac, hip, knee, ankle, foot, and toe joints in 1857 stimulated the subsequent history of surgical joint denervation. Comparing his investigations with modern joint denervation methods, developed by pioneers like Albrecht Wilhelm or A. Lee Dellon, shows his great exactitude and anatomical correspondence despite different current terminology. Clinical series of modern surgical joint denervations reveal success rates of up to 80% with reliable long-term results.  The history of joint denervation with Rüdinger as its important protagonist offers inspiring insights into the evolution of surgical techniques and exemplifies the value of descriptive functional anatomy, even if surgical application may not have been realized until a century later. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  15. Formation of a physiological reverse shoulder joint.

    PubMed

    Lerner, Markus; Turkmen, Ismail; Bernd, Ludger

    2016-01-20

    Congenital shoulder deformities are rarely seen in orthopaedic practice. Proximal humeral defects and glenoid hypoplasia have been reported separately in the literature. We present a case involving a 31-year-old woman having a cosmetic problem with her upper arm who was diagnosed with reverse shoulder joint deformity. This article presents the clinical, radiological and biomechanical findings of a physiological reverse shoulder joint. This is the first such reported case. 2016 BMJ Publishing Group Ltd.

  16. [Divorce and joint physical custody].

    PubMed

    Golse, B

    2014-04-01

    This work first recalls the definition of joint physical custody, as well as the current legal procedure for obtaining it, its practical implementation, the financial implications for parents, and finally some statistics. Some psychological and psychopathological reflections on the impact of divorce on children are then presented before considering the question of joint physically custody with regard to attachment theory and depending on the age of the child (a great caution seems to be required before three years). The article concludes with a brief discussion of parental alienation syndrome. Copyright © 2014. Published by Elsevier SAS.

  17. The Joint Accomplishment of Identity

    ERIC Educational Resources Information Center

    Hand, Victoria; Gresalfi, Melissa

    2015-01-01

    Identity has become a central concept in the analysis of learning from social perspectives. In this article, we draw on a situative perspective to conceptualize identity as a "joint accomplishment" between individuals and their interactions with norms, practices, cultural tools, relationships, and institutional and cultural contexts.…

  18. Reusable Solid Rocket Motor Nozzle Joint-4 Thermal Analysis

    NASA Technical Reports Server (NTRS)

    Clayton, J. Louie

    2001-01-01

    This study provides for development and test verification of a thermal model used for prediction of joint heating environments, structural temperatures and seal erosions in the Space Shuttle Reusable Solid Rocket Motor (RSRM) Nozzle Joint-4. The heating environments are a result of rapid pressurization of the joint free volume assuming a leak path has occurred in the filler material used for assembly gap close out. Combustion gases flow along the leak path from nozzle environment to joint O-ring gland resulting in local heating to the metal housing and erosion of seal materials. Analysis of this condition was based on usage of the NASA Joint Pressurization Routine (JPR) for environment determination and the Systems Improved Numerical Differencing Analyzer (SINDA) for structural temperature prediction. Model generated temperatures, pressures and seal erosions are compared to hot fire test data for several different leak path situations. Investigated in the hot fire test program were nozzle joint-4 O-ring erosion sensitivities to leak path width in both open and confined joint geometries. Model predictions were in generally good agreement with the test data for the confined leak path cases. Worst case flight predictions are provided using the test-calibrated model. Analysis issues are discussed based on model calibration procedures.

  19. Joint kinematics of surgeons during lumbar pedicle screw placement.

    PubMed

    Park, Jeong-Yoon; Kim, Kyung-Hyun; Kuh, Sung-Uk; Chin, Dong-Kyu; Kim, Keun-Su; Cho, Yong-Eun

    2016-12-01

    A surgical robot for spine surgery has recently been developed. The objective is to assess the joint kinematics of the surgeon during spine surgery. We enrolled 18 spine surgeons, who each performed pedicle screw placement, and used an optoelectronic motion analysis system. Using three-dimensional (3D) motion images, distance changes in five joints and angle changes in six joints were calculated during surgery. Distance fluctuations increased gradually from the proximal to the distal joint. Angle fluctuations were largest at the distal point but did not gradually increase, and the elbow showed the second largest fluctuation. Changes along the X axis were larger than those of the Y and Z axes. The distances gradually increased from proximal portions of the body to the hand. In angle changes, the elbow was most dynamic during pedicle screw placement. The surgeons' whole joints carry out a harmonic role during lumbar pedicle screw placement. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  20. Analysis of the stress-strain state in single overlap joints using piezo-ceramic actuators

    NASA Astrophysics Data System (ADS)

    Pǎltânea, Veronica; Pǎltânea, Gheorghe; Popovici, Dorina; Jiga, Gabriel; Papanicolaou, George

    2014-05-01

    In this paper is presented a 2D approach to finite element modeling and an analytical calculus of a single lap bonded joint. As adherent material were selected a sheet of wood, aluminum and titanium. For adhesive part were selected Bison Super Wood D3 in case of the wood single lap joint and an epoxy resin type DGEBA-TETA for gluing together aluminum and titanium parts. In the article is described a combined method, which consists in the placement of the piezoelectric actuator inside of the adhesive part, in order to determine the tensile stress in the overlap joint. A comparison between the analytical and numerical results has been achieved through a multiphysics modeling - electrical and mechanical coupled problem. The technique used to calculate the mechanical parameters (First Principal Stress, displacements) was the three-point bending test, where different forces were applied in the mid-span of the structure, in order to maintain a constant displacement rate. The length of the overlap joint was modified from 20 to 50 mm.

  1. Joint attention in Down syndrome: A meta-analysis.

    PubMed

    Hahn, Laura J; Loveall, Susan J; Savoy, Madison T; Neumann, Allie M; Ikuta, Toshikazu

    2018-07-01

    Some studies have indicated that joint attention may be a relative strength in Down syndrome (DS), but other studies have not. To conduct a meta-analysis of joint attention in DS to more conclusively determine if this is a relative strength or weakness when compared to children with typical development (TD), developmental disabilities (DD), and autism spectrum disorder (ASD). Journal articles published before September 13, 2016, were identified by using the search terms "Down syndrome" and "joint attention" or "coordinating attention". Identified studies were reviewed and coded for inclusion criteria, descriptive information, and outcome variables. Eleven studies (553 participants) met inclusion criteria. Children with DS showed similar joint attention as TD children and higher joint attention than children with DD and ASD. Meta-regression revealed a significant association between age and joint attention effect sizes in the DS vs. TD contrast. Joint attention appears to not be a weakness for children with DS, but may be commensurate with developmental level. Joint attention may be a relative strength in comparison to other skills associated with the DS behavioral phenotype. Early interventions for children with DS may benefit from leveraging joint attention skills. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Anatomy and Biomechanics of the Finger Proximal Interphalangeal Joint.

    PubMed

    Pang, Eric Quan; Yao, Jeffrey

    2018-05-01

    A complete understanding of the normal anatomy and biomechanics of the proximal interphalangeal joint is critical when treating pathology of the joint as well as in the design of new reconstructive treatments. The osseous anatomy dictates the principles of motion at the proximal interphalangeal joint. Subsequently, the joint is stabilized throughout its motion by the surrounding proximal collateral ligament, accessory collateral ligament, and volar plate. The goal of this article is to review the normal anatomy and biomechanics of the proximal interphalangeal joint and its associated structures, most importantly the proper collateral ligament, accessory collateral ligament, and volar plate. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. NASA Boeing 737 Aircraft Test Results from 1996 Joint Winter Runway Friction Measurement Program

    NASA Technical Reports Server (NTRS)

    Yager, Thomas J.

    1996-01-01

    A description of the joint test program objectives and scope is given together with the performance capability of the NASA Langley B-737 instrumented aircraft. The B-737 test run matrix conducted during the first 8 months of this 5-year program is discussed with a description of the different runway conditions evaluated. Some preliminary test results are discussed concerning the Electronic Recording Decelerometer (ERD) readings and a comparison of B-737 aircraft braking performance for different winter runway conditions. Detailed aircraft parameter time history records, analysis of ground vehicle friction measurements and harmonization with aircraft braking performance, assessment of induced aircraft contaminant drag, and evaluation of the effects of other factors on aircraft/ground vehicle friction performance will be documented in a NASA Technical Report which is being prepared for publication next year.

  4. Investigation Leads to Improved Understanding of Space Shuttle RSRM Internal Insulation Joints

    NASA Technical Reports Server (NTRS)

    McWhorter, Bruce B.; Bolton, Doug E.; Hicken, Steve V.; Allred, Larry D.; Cook, Dave J.

    2003-01-01

    The Space Shuttle Reusable Solid Rocket Motor (RSRM) uses an internal insulation J-joint design for the mated insulation interface between two assembled RSRM segments. In this assembled (mated) segment configuration, this J-joint design serves as a thermal barrier to prevent hot gases from affecting the case field joint metal surfaces and O-rings. A pressure sensitive adhesive (PSA) provides some adhesion between the two mated insulation surfaces. In 1995, after extensive testing, a new ODC-free PSA (free of ozone depleting chemicals) was selected for flight on RSRM-55 (STS-78). Post-flight inspection revealed that the J-joint, equipped with the new ODC-free PSA, did not perform well. Hot gas seeped inside the J-joint interface. Although not a flight safety threat, the J-joint hot gas intrusion on RSRM-55 was a mystery to the investigators since the PSA had previously worked well on a full-scale static test. A team was assembled to study the J-joint and PSA further. All J-joint design parameters, measured data, and historical performance data were re-reviewed and evaluated by subscale testing and analysis. Although both the ODC-free and old PSA were weakened by humidity, the ODC-free PSA strength was lower to start with. Another RSRM full-scale static test was conducted in 1998 and intentionally duplicated the gas intrusion. This test, along with many concurring tests, showed that if a J-joint was 1) mated with the new ODC-free PSA, 2) exposed to a history of high humidity (Kennedy Space Center levels), and 3) also a joint which experienced significant but normal joint motion (J-joint deformation resulting from motor pressurization dynamics) then that J-joint would open (allow gas intrusion) during motor operation. When all of the data from the analyses, subscale tests, and full-scale tests were considered together, a theory emerged. Most of the joint motion on the RSRM occurs early in motor operation at which point the J-joints are pulled into tension. If the new

  5. The reliability of knee joint position testing using electrogoniometry

    PubMed Central

    Piriyaprasarth, Pagamas; Morris, Meg E; Winter, Adele; Bialocerkowski, Andrea E

    2008-01-01

    Background The current investigation examined the inter- and intra-tester reliability of knee joint angle measurements using a flexible Penny and Giles Biometric® electrogoniometer. The clinical utility of electrogoniometry was also addressed. Methods The first study examined the inter- and intra-tester reliability of measurements of knee joint angles in supine, sitting and standing in 35 healthy adults. The second study evaluated inter-tester and intra-tester reliability of knee joint angle measurements in standing and after walking 10 metres in 20 healthy adults, using an enhanced measurement protocol with a more detailed electrogoniometer attachment procedure. Both inter-tester reliability studies involved two testers. Results In the first study, inter-tester reliability (ICC[2,10]) ranged from 0.58–0.71 in supine, 0.68–0.79 in sitting and 0.57–0.80 in standing. The standard error of measurement between testers was less than 3.55° and the limits of agreement ranged from -12.51° to 12.21°. Reliability coefficients for intra-tester reliability (ICC[3,10]) ranged from 0.75–0.76 in supine, 0.86–0.87 in sitting and 0.87–0.88 in standing. The standard error of measurement for repeated measures by the same tester was less than 1.7° and the limits of agreement ranged from -8.13° to 7.90°. The second study showed that using a more detailed electrogoniometer attachment protocol reduced the error of measurement between testers to 0.5°. Conclusion Using a standardised protocol, reliable measures of knee joint angles can be gained in standing, supine and sitting by using a flexible goniometer. PMID:18211714

  6. Use of Strain Measurements from Acoustic Bench Tests of the Battleship Flowliner Test Articles To Link Analytical Model Results to In-Service Resonant Response

    NASA Technical Reports Server (NTRS)

    Frady, Greg; Smaolloey, Kurt; LaVerde, Bruce; Bishop, Jim

    2004-01-01

    The paper will discuss practical and analytical findings of a test program conducted to assist engineers in determining which analytical strain fields are most appropriate to describe the crack initiating and crack propagating stresses in thin walled cylindrical hardware that serves as part of the Space Shuttle Main Engine's fuel system. In service the hardware is excited by fluctuating dynamic pressures in a cryogenic fuel that arise from turbulent flow/pump cavitation. A bench test using a simplified system was conducted using acoustic energy in air to excite the test articles. Strain measurements were used to reveal response characteristics of two Flowliner test articles that are assembled as a pair when installed in the engine feed system.

  7. Prevalence of sesamoid bones in the interphalangeal joint of the thumb and fingers: a radiographic study.

    PubMed

    Seki, Yasuhiro; Hoshino, Yuko; Kuroda, Hiroshi

    2013-10-01

    The prevalence of sesamoid bones in the hands has been reported in some previous articles. Most of them, however, have reported sesamoid bones of the metacarpophalangeal joint of the hand and of the interphalangeal (IP) joint of the thumb. The present study investigates the prevalence of sesamoid bones of the IP joint of the thumb and fingers. A retrospective review of radiologic views of the IP joints in the thumb or fingers was performed, including a total of 650 patients (1,096 thumbs or fingers). Sesamoid bones were found in the IP joint of the thumb at 67% (212 of 318), while the index, middle, ring, little fingers had sesamoid bones in the proximal interphlangeal (PIP) joint at 0% (0 of 172), 0.4% (1 of 244), 0.5% (1 of 183), and 1% (2 of 179), respectively. None of the four fingers had sesamoid bones in the distal IP joint. Previous articles have described the similar prevalence to the present study, of sesamoid bones of the IP joint of the thumb, while some others reported the different prevalence. About the PIP joint, no previous articles have found a sesamoid bone. Because the lateral X-ray view is more accurate and suitable to evaluate sesamoid bones, we used the lateral one for the present study. The knowledge that sesamoid bones occurs at these rates in the thumb IP joint and finger PIP joints is helpful to differentiate chip fractures from sesamoid bones near the IP joint, including the PIP joint. Copyright © 2012 Wiley Periodicals, Inc.

  8. Waterhammer Modeling for the Ares I Upper Stage Reaction Control System Cold Flow Development Test Article

    NASA Technical Reports Server (NTRS)

    Williams, Jonathan H.

    2010-01-01

    The Upper Stage Reaction Control System provides three-axis attitude control for the Ares I launch vehicle during active Upper Stage flight. The system design must accommodate rapid thruster firing to maintain the proper launch trajectory and thus allow for the possibility to pulse multiple thrusters simultaneously. Rapid thruster valve closure creates an increase in static pressure, known as waterhammer, which propagates throughout the propellant system at pressures exceeding nominal design values. A series of development tests conducted in the fall of 2009 at Marshall Space Flight Center were performed using a water-flow test article to better understand fluid performance characteristics of the Upper Stage Reaction Control System. A subset of the tests examined waterhammer along with the subsequent pressure and frequency response in the flight-representative system and provided data to anchor numerical models. This thesis presents a comparison of waterhammer test results with numerical model and analytical results. An overview of the flight system, test article, modeling and analysis are also provided.

  9. Waterhammer modeling for the Ares I Upper Stage Reaction Control System cold flow development test article

    NASA Astrophysics Data System (ADS)

    Williams, Jonathan Hunter

    The Upper Stage Reaction Control System provides in-flight three-axis attitude control for the Ares I Upper Stage. The system design must accommodate rapid thruster firing to maintain proper launch trajectory and thus allow for the possibility to pulse multiple thrusters simultaneously. Rapid thruster valve closure creates an increase in static pressure, known as waterhammer, which propagates throughout the propellant system at pressures exceeding nominal design values. A series of development tests conducted at Marshall Space Flight Center in 2009 were performed using a water-flow test article to better understand fluid characteristics of the Upper Stage Reaction Control System. A subset of the tests examined the waterhammer pressure and frequency response in the flight-representative system and provided data to anchor numerical models. This thesis presents a comparison of waterhammer test results with numerical model and analytical results. An overview of the flight system, test article, modeling and analysis are also provided.

  10. European Service Module Structural Test Article Load onto Guppy for Transport to Denver Colorado

    NASA Image and Video Library

    2017-06-23

    At Kennedy Space Center's Shuttle Landing Facility in Florida, workers move the Orion service module structural test article for Exploration Mission-1 (EM-1), built by the European Space Agency, inside NASA's Super Guppy aircraft. The module is secured inside the aircraft and shipped to Lockheed Martin's Denver facility to undergo testing. The Orion spacecraft will launch atop the agency's Space Launch System rocket on EM-1 in 2019

  11. [Fetal bone and joint disorders].

    PubMed

    Jakobovits, Akos

    2008-12-21

    The article discusses the physiology and pathology of fetal bone and joint development and functions. The bones provide static support for the body. The skull and the bones of spinal column encase the central and part of the peripheral nervous system. The ribs and the sternum shield the heart and the lungs, while the bones of the pelvis protect the intraabdominal organs. Pathological changes of these bony structures may impair the functions of the respective systems or internal organs. Movements of the bones are brought about by muscles. The deriving motions are facilitated by joints. Bony anomalies of the extremities limit their effective functions. Apart from skeletal and joint abnormalities, akinesia may also be caused by neurological, muscular and skin diseases that secondarily affect the functions of bones and joints. Such pathological changes may lead to various degrees of physical disability and even to death. Some of the mentioned anomalies are recognizable in utero by ultrasound. The diagnosis may serve as medical indication for abortion in those instances when the identified abnormality is incompatible with independent life.

  12. 2011 Ground Testing Highlights Article

    NASA Technical Reports Server (NTRS)

    Ross, James C.; Buchholz, Steven J.

    2011-01-01

    Two tests supporting development of the launch abort system for the Orion MultiPurpose Crew Vehicle were run in the NASA Ames Unitary Plan wind tunnel last year. The first test used a fully metric model to examine the stability and controllability of the Launch Abort Vehicle during potential abort scenarios for Mach numbers ranging from 0.3 to 2.5. The aerodynamic effects of the Abort Motor and Attitude Control Motor plumes were simulated using high-pressure air flowing through independent paths. The aerodynamic effects of the proximity to the launch vehicle during the early moments of an abort were simulated with a remotely actuated Service Module that allowed the position relative to the Crew Module to be varied appropriately. The second test simulated the acoustic environment around the Launch Abort Vehicle caused by the plumes from the 400,000-pound thrust, solid-fueled Abort Motor. To obtain the proper acoustic characteristics of the hot rocket plumes for the flight vehicle, heated Helium was used. A custom Helium supply system was developed for the test consisting of 2 jumbo high-pressure Helium trailers, a twelve-tube accumulator, and a 13MW gas-fired heater borrowed from the Propulsion Simulation Laboratory at NASA Glenn Research Center. The test provided fluctuating surface pressure measurements at over 200 points on the vehicle surface that have now been used to define the ground-testing requirements for the Orion Launch Abort Vehicle.

  13. Three-dimensional evaluation of the facet joints

    NASA Astrophysics Data System (ADS)

    Folio, Les R.

    1990-04-01

    Computerized tomography and magnetic resonance imaging nave revolurionalized analysis of vertebral anatomy and pathology. Further advances with 3-dimensional imaging have recently become an important adjunct for diagnosis and treatment in structural abnormalities. Facets are intimately related to their surrounding musculature and malalignment may cause pain directly or indirectly. High resolution 3-dimensional reformations of CT Scans give us new insight on structure and function of facet joints, since their motion and architecture are ever complex. It is well documented in the literature that facet joint biomecnanics is a partial contributor to the myriad at causes of low back The term "facet Joint syndrome" was coined in 1933 by GhorMley.3 The osteopathic lesion complex is well defined by LeRoy and McCole and comparison of roentgenographic findings before and after manipulation has teen described by Long and Lioyd.4,5 since alterations in facet biamechanics are an important aspect of osteopathic manipulative therapy (OT), 3-dimensional hign resolution imaging will prove to be a great asset in osteopathic research. Rotating the spine allows for different viewing perspectives to provide optimal and consistent measurements of the facet joint. Rotations are performed on the X, Y and 7, axis and measurements pre and post-manipulation are performed and compared on matching axis and perspectives. Rotation about the X, Y and Z axis help appreciate the 3-dimensionality of the vertebral column to project to the viewer a feeling that the spine is floating in space before them. This does give the viewer a 3-D understanding of the object however, only at a perspective at a Lime.

  14. Early detection and progression of decay in L-joints and lap-joints in a moderate decay hazard zone

    Treesearch

    Carol A. Clausen; Terry L. Highley; Daniel L. Lindner

    2006-01-01

    Accelerated test methods are needed to evaluate the initiation and progression of decay in wood exposed aboveground. The relationship between test conditions and initiation of decay, however, is poorly understood. Southern pine and maple L-joints and lap-joints were exposed aboveground in a configuration that encouraged water entrapment at the Valley View Experimental...

  15. Solder Joint Health Monitoring Testbed

    NASA Technical Reports Server (NTRS)

    Delaney, Michael M.; Flynn, James; Browder, Mark

    2009-01-01

    A method of monitoring the health of selected solder joints, called SJ-BIST, has been developed by Ridgetop Group Inc. under a Small Business Innovative Research (SBIR) contract. The primary goal of this research program is to test and validate this method in a flight environment using realistically seeded faults in selected solder joints. An additional objective is to gather environmental data for future development of physics-based and data-driven prognostics algorithms. A test board is being designed using a Xilinx FPGA. These boards will be tested both in flight and on the ground using a shaker table and an altitude chamber.

  16. Wormhole Formation in RSRM Nozzle Joint Backfill

    NASA Technical Reports Server (NTRS)

    Stevens, J.

    2000-01-01

    The RSRM nozzle uses a barrier of RTV rubber upstream of the nozzle O-ring seals. Post flight inspection of the RSRM nozzle continues to reveal occurrence of "wormholes" into the RTV backfill. The term "wormholes", sometimes called "gas paths", indicates a gas flow path not caused by pre-existing voids, but by a little-understood internal failure mode of the material during motor operation. Fundamental understanding of the mechanics of the RSRM nozzle joints during motor operation, nonlinear viscoelastic characterization of the RTV backfill material, identification of the conditions that predispose the RTV to form wormholes, and screening of candidate replacement materials is being pursued by a joint effort between Thiokol Propulsion, NASA, and the Army Propulsion & Structures Directorate at Redstone Arsenal. The performance of the RTV backfill in the joint is controlled by the joint environment. Joint movement, which applies a tension and shear load on the material, coupled with the introduction of high pressure gas in combination create an environment that exceeds the capability of the material to withstand the wormhole effect. Little data exists to evaluate why the material fails under the modeled joint conditions, so an effort to characterize and evaluate the material under these conditions was undertaken. Viscoelastic property data from characterization testing will anchor structural analysis models. Data over a range of temperatures, environmental pressures, and strain rates was used to develop a nonlinear viscoelastic model to predict material performance, develop criteria for replacement materials, and quantify material properties influencing wormhole growth. Three joint simulation analogs were developed to analyze and validate joint thermal barrier (backfill) material performance. Two exploratory tests focus on detection of wormhole failure under specific motor operating conditions. A "validation" test system provides data to "validate" computer models and

  17. EXPLORATION OF SCORE AGREEMENT ON A MODIFIED UPPER QUARTER Y-BALANCE TEST KIT AS COMPARED TO THE UPPER QUARTER Y-BALANCE TEST.

    PubMed

    Cramer, Josh; Quintero, Miguel; Rhinehart, Alex; Rutherford, Caitlin; Nasypany, Alan; May, James; Baker, Russell T

    2017-02-01

    Physical performance measures (PPMs) such as The Star Excursion Balance Test (SEBT) and the Y-Balance Test (YBT) are functional movement tests used to assess participants' dynamic balance, which can be a vital component in physical exams to identify predisposing factors for risk of injury. The YBT is a functional assessment tool for the upper and lower body. It evolved from the SEBT, which has been previously used in research as a lower body functional assessment. It is comprised of fewer movement directions, which help limit fatigue. The YBT kit is a commercialized tool, which may pose barriers for clinicians with limited budgets and/or strict approval process for purchasing capital items in their clinics, especially healthcare providers in the secondary school setting. The cost may also pose a barrier for researchers with limited budgets. A less expensive, easy to make kit, may provide clinicians an opportunity to integrate functional testing into their evaluation or research. The purpose of this pilot study was to describe a cost efficient method to gather participant's upper quarter YBT (UQYBT) measurements and examine the inter- and intra-rater score agreement between this method and the commercial YBT measurements. A convenience sample of 20 physically active participants volunteered to participate in a comparison study of the of Upper Quarter Y-Balance Test (UQYBT) using the commercialized kit and the Modified Upper Quarter Y-Balance Test kit (mUQYBT) made with three cloth tape measures, athletic tape, a goniometer and three 2x4x8 wood blocks. A Pearson Product Moment correlation and Bland-Altman analyses were used to examine the relationship between intra-rater scores comparing the UQYBT and mUQYBT. Inter-rater scores were analyzed using intraclass correlation coefficients (ICC) (2,1) and Bland-Altman analyses. All Pearson Product Moment r-values for intra-rater scores were greater than .96 and statistically significant at p<0.05. Coefficients of

  18. [Gender analysis among articles published in Enfermedades Infecciosas y Microbiología Clínica (2001-2005)].

    PubMed

    Aleixandre-Benavent, Rafael; González-Alcaide, Gregorio; Alonso-Arroyo, Adolfo; Castellano-Gómez, Miguel; Valderrama-Zurián, Juan Carlos

    2007-12-01

    There is growing concern for promoting equality between sexes and full integration of women in research activities. The purpose of this study is to identify the bibliometric characteristics of articles published during the 2001-2005 period in Enfermedades Infecciosas y Microbiología Clínica (EIMC) from the perspective of gender. EIMC records for 2001-2005 were obtained from the Science Citation Index database and differences according to sex were calculated for the following indicators: year of publication, type of document, number and order of author signatures, number of collaborators, and the signature/article index at the institutional and geographical level. A total of 2,163 authors were identified, 1,220 (56.4%) men and 943 (43.6%) women. The greatest of contribution from women was in original articles (42.32% of signatures). Excluding the Centro Nacional de Microbiología (Spanish National Center for Microbiology), the participation of women was lower than men in the most productive institutions. There were significant differences regarding the number of papers published and the number of collaborators; with greater productivity for men and a higher rate of collaboration for women. Studies on scientific activity according to gender provide essential information to establish the basis for a policy of equality in this regard. A yearly increase of almost 1% was seen in the number of female authors contributing articles to the EIMC, which, if the trend continues, will result in parity in coming years. Nevertheless, the presence of women in positions of high productivity remains low. The causes of this difference should be identified and corrected.

  19. Waste Receiving and Processing (WRAP) Facility PMS Test Report For Data Management System (DMS) Security Test DMS-Y2K

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    PALMER, M.E.

    1999-09-21

    Test Plan HNF-4351 defines testing requirements for installation of a new server in the WRAP Facility. This document shows the results of the test reports on the DMS-Y2K and DMS-F81 (Security) systems.

  20. Effect of Strain Rate on Joint Strength and Failure Mode of Lead-Free Solder Joints

    NASA Astrophysics Data System (ADS)

    Lin, Jian; Lei, Yongping; Fu, Hanguang; Guo, Fu

    2018-03-01

    In surface mount technology, the Sn-3.0Ag-0.5Cu solder joint has a shorter impact lifetime than a traditional lead-tin solder joint. In order to improve the impact property of SnAgCu lead-free solder joints and identify the effect of silver content on tensile strength and impact property, impact experiments were conducted at various strain rates on three selected SnAgCu based solder joints. It was found that joint failure mainly occurred in the solder material with large plastic deformation under low strain rate, while joint failure occurred at the brittle intermetallic compound layer without any plastic deformation at a high strain rate. Joint strength increased with the silver content in SnAgCu alloys in static tensile tests, while the impact property of the solder joint decreased with increasing silver content. When the strain rate was low, plastic deformation occurred with failure and the tensile strength of the Sn-3.0Ag-0.5Cu solder joint was higher than that of Sn-0.3Ag-0.7Cu; when the strain rate was high, joint failure mainly occurred at the brittle interface layer and the Sn-0.3Ag-0.7Cu solder joint had a better impact resistance with a thinner intermetallic compound layer.

  1. Acoustic emission analysis: A test method for metal joints bonded by adhesives

    NASA Technical Reports Server (NTRS)

    Brockmann, W.; Fischer, T.

    1978-01-01

    Acoustic emission analysis is applied to study adhesive joints which had been subjected to mechanical and climatic stresses, taking into account conditions which make results applicable to adhesive joints used in aerospace technology. Specimens consisting of the alloy AlMgSi0.5 were used together with a phenolic resin adhesive, an epoxy resin modified with a polyamide, and an epoxy resin modified with a nitrile. Results show that the acoustic emission analysis provides valuable information concerning the behavior of adhesive joints under load and climatic stresses.

  2. A Note on Testing Mediated Effects in Structural Equation Models: Reconciling Past and Current Research on the Performance of the Test of Joint Significance

    ERIC Educational Resources Information Center

    Valente, Matthew J.; Gonzalez, Oscar; Miocevic, Milica; MacKinnon, David P.

    2016-01-01

    Methods to assess the significance of mediated effects in education and the social sciences are well studied and fall into two categories: single sample methods and computer-intensive methods. A popular single sample method to detect the significance of the mediated effect is the test of joint significance, and a popular computer-intensive method…

  3. The feasibility of measuring joint angular velocity with a gyro-sensor.

    PubMed

    Arai, Takeshi; Obuchi, Shuichi; Shiba, Yoshitaka; Omuro, Kazuya; Nakano, Chika; Higashi, Takuya

    2008-01-01

    To determine the reliability of an assessment of joint angular velocity using a gyro-sensor and to examine the relationship between ankle angular velocity and physical functions. Cross-sectional. Kinesiology laboratory. Twenty healthy young adults (mean age, 22.5 y) and 113 community-dwelling older adults (mean age, 75.1 y). Not applicable. Maximal ankle joint velocity was measured using a gyro-sensor during heel-rising and jumping with knee extended. The intraclass correlation coefficient (ICC) was used to determine the intertester and intratester reliability. The Pearson correlation coefficient was used to examine the relationships between maximal ankle joint velocity and isometric muscle strength and isokinetic muscle power in young adults and also to examine the relationships between maximal ankle joint velocity and functional performance measurements such as walking time in older adults. High reliability was found for intertester (ICC=.96) and intratester reliability (ICC=.96). The data from the gyro-sensor highly correlated with muscle strength (r range, .62-.68; P<.01) and muscle power (r range, .45-.79; P range, .01-.05). In older subjects, mobility functions significantly correlated with the angular velocity of ankle plantarflexion. Measurement of ankle angular velocity using a gyro-sensor is both reliable and feasible, with the results representing a significant correlation to muscle power and performance measurements.

  4. Biomechanics of the natural, arthritic, and replaced human ankle joint

    PubMed Central

    2014-01-01

    The human ankle joint complex plays a fundamental role in gait and other activities of daily living. At the same time, it is a very complicated anatomical system but the large literature of experimental and modelling studies has not fully described the coupled joint motion, position and orientation of the joint axis of rotation, stress and strain in the ligaments and their role in guiding and stabilizing joint motion, conformity and congruence of the articular surfaces, patterns of contact at the articular surfaces, patterns of rolling and sliding at the joint surfaces, and muscle lever arm lengths. The present review article addresses these issues as described in the literature, reporting the most recent relevant findings. PMID:24499639

  5. Income-related health transfers principles and orderings of joint distributions of income and health.

    PubMed

    Khaled, Mohamad A; Makdissi, Paul; Yazbeck, Myra

    2018-01-01

    The objective of this article is to provide the analyst with the necessary tools that allow for a robust ordering of joint distributions of health and income. We contribute to the literature on the measurement and inference of socioeconomic health inequality in three distinct but complementary ways. First, we provide a formalization of the socioeconomic health inequality-specific ethical principle introduced by Erreygers et al. (2012) . Second, we propose new graphical tools and dominance tests for the identification of robust orderings of joint distributions of income and health associated with this new ethical principle. Finally, based on both pro-poor and pro-extreme ranks ethical principles we address a very important aspect of dominance literature: the inference. To illustrate the empirical relevance of the proposed approach, we compare joint distributions of income and a health-related behavior in the United States in 1997 and 2014. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. QM-8 field joint protection system, volume 7

    NASA Technical Reports Server (NTRS)

    Hale, Elgie

    1989-01-01

    The pre-launch functioning data of the Field Joint Protection System (JPS) used on QM-8 are presented. Also included is the post fire condition of the JPS components following the test firing of the motor. The JPS components are: field joint heaters; field joint sensors; field joint moisture seal; moisture seal kevlar retaining straps; field joint external extruded cork insulation; vent valve; power cables; and igniter heater.

  7. Joint US/Russia TU-144 Engine Ground Tests

    NASA Technical Reports Server (NTRS)

    Acosta, Waldo A.; Balser, Jeffrey S.; McCartney, Timothy P.; Richter, Charles A.; Woike, Mark R.

    1997-01-01

    Two engine research experiments were recently completed in Moscow, Russia using an engine from the Tu-144 supersonic transport airplane. This was a joint project between the United States and Russia. Personnel from the NASA Lewis Research Center, General Electric Aircraft Engines, Pratt & Whitney, the Tupolev Design Bureau, and EBP Aircraft LTD worked together as a team to overcome the many technical and cultural challenges. The objective was to obtain large scale inlet data that could be used in the development of a supersonic inlet system for a future High Speed Civil Transport (HSCT). The-first experiment studied the impact of typical inlet structures that have trailing edges in close proximity to the inlet/engine interface plane on the flow characteristics at that plane. The inlet structure simulated the subsonic diffuser of a supersonic inlet using a bifurcated splitter design. The centerbody maximum diameter was designed to permit choking and slightly supercritical operation. The second experiment measured the reflective characteristics of the engine face to incoming perturbations of pressure amplitude. The basic test rig from the first experiment was used with a longer spacer equipped with fast actuated doors. All the objectives set forth at the beginning of the project were met.

  8. An Analysis of the Effectiveness of First Article Testing and Approval Requirements

    DTIC Science & Technology

    1976-12-01

    EFFECTIVENESS OF FIRST ARTICLE TESTING AND ^APPROVAL REQUIREMENTS •>’r\\ a /’ j/’? by Harold F./fandy J / " / Robert Äaüner^jwifc II d ’^au...covered by design specifications. c - ASPR Criteria. Finally, there are several additional cir- cumstances cited in ASPR 1-1902 when the Government’s...select the alternate provision contained in ASPR 7-104.55( c ) which authorizes the contractor, upon written approval by the contracting officer, to

  9. From Joint Experimentation to Laissez-Faire: Transdisciplinary Innovation Research for the Institutional Strengthening of a Water Users Association in Khorezm, Uzbekistan

    ERIC Educational Resources Information Center

    Djanibekov, Nodir; Hornidge, Anna-Katharina; Ul-Hassan, Mehmood

    2012-01-01

    Purpose: This article assesses a participatory action and innovation research experience, in which project researchers, farmers and staff members of a local water users association (WUA) came together to: (a) jointly test and adapt a social mobilization and institutional strengthening approach according to the local context, and by doing so, to…

  10. Space Suit Joint Torque Measurement Method Validation

    NASA Technical Reports Server (NTRS)

    Valish, Dana; Eversley, Karina

    2012-01-01

    In 2009 and early 2010, a test method was developed and performed to quantify the torque required to manipulate joints in several existing operational and prototype space suits. This was done in an effort to develop joint torque requirements appropriate for a new Constellation Program space suit system. The same test method was levied on the Constellation space suit contractors to verify that their suit design met the requirements. However, because the original test was set up and conducted by a single test operator there was some question as to whether this method was repeatable enough to be considered a standard verification method for Constellation or other future development programs. In order to validate the method itself, a representative subset of the previous test was repeated, using the same information that would be available to space suit contractors, but set up and conducted by someone not familiar with the previous test. The resultant data was compared using graphical and statistical analysis; the results indicated a significant variance in values reported for a subset of the re-tested joints. Potential variables that could have affected the data were identified and a third round of testing was conducted in an attempt to eliminate and/or quantify the effects of these variables. The results of the third test effort will be used to determine whether or not the proposed joint torque methodology can be applied to future space suit development contracts.

  11. Minimally invasive arthrodesis for chronic sacroiliac joint dysfunction using the SImmetry SI Joint Fusion system.

    PubMed

    Miller, Larry E; Block, Jon E

    2014-01-01

    Chronic sacroiliac (SI) joint-related low back pain (LBP) is a common, yet under-diagnosed and undertreated condition due to difficulties in accurate diagnosis and highly variable treatment practices. In patients with debilitating SI-related LBP for at least 6 months duration who have failed conservative management, arthrodesis is a viable option. The SImmetry(®) SI Joint Fusion System is a novel therapy for SI joint fusion, not just fixation, which utilizes a minimally invasive surgical approach, instrumented fixation for immediate stability, and joint preparation with bone grafting for a secure construct in the long term. The purpose of this report is to describe the minimally invasive SI Joint Fusion System, including patient selection criteria, implant characteristics, surgical technique, postoperative recovery, and biomechanical testing results. Advantages and limitations of this system will be discussed.

  12. Phenotypic disparity of the elbow joint in domestic dogs and wild carnivores.

    PubMed

    Figueirido, Borja

    2018-05-16

    In this article, I use geometric morphometrics in 2D from a sample of 366 elbow joints to quantify phenotypic disparity in domestic dog breeds, in wild canids, and across the order Carnivora. The elbow joint is a well-established morphological indicator of forearm motion and, by extension, of functional adaptations towards locomotor or predatory behavior in living carnivores. The study of the elbow joint in domestic dogs allows the exploration of potential convergences between (i) pursuit predators and fast-running dogs, and (ii) ambush predators and fighting breeds. The results indicate that elbow shape disparity among domestic dogs exceeds that in wolves; it is comparable to the disparity of wild Caninae, but is significantly lower than the one observed throughout Canidae and Carnivora. Moreover, fast-running and fighting breeds are not convergent in elbow joint shape with extreme pursuit and ambush wild carnivores, respectively. The role of artificial selection and developmental constraints in shaping limb phenotypic disparity through the extremely fast evolution of the domestic dog is discussed in the light of this new evidence. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  13. Test Validation of the Repair to the Space Station Solar Alpha Rotary Joint

    NASA Technical Reports Server (NTRS)

    Allmon, Curtis; Wilkinson, Will; Loewenthal, Stu

    2010-01-01

    The Solar Array Alpha Joint Lubrication Interval Test (SARJ LITE) test rig was built as a method to evaluate the performance of the grease repair on the Starboard SARJ of the International Space Station (ISS) . The on-orbit SARJ was temporarily parked after receiving significant damage on one of its race ring surfaces as a result of inadequate lu brication (high dry contact friction) and unaccounted for roller traction kinematics. In a scaled down rig, flight-like roller bearings wer e preloaded and cycled on a nitrided 15-5 race surface. Grease was ad ded to the track and with instrumentation monitoring performance, trending data will be extracted and used to determine lubrication interva ls for both Port and Starboard ISS SARJ?s. The grease lubrication was found to be effective in eliminating the high friction that contributed to the onorbit race damage.

  14. Biaxially textured articles formed by powder metallurgy

    DOEpatents

    Goyal, Amit; Williams, Robert K.; Kroeger, Donald M.

    2005-01-25

    A biaxially textured alloy article having a magnetism less than pure Ni includes a rolled and annealed compacted and sintered powder-metallurgy preform article, the preform article having been formed from a powder mixture selected from the group of mixtures consisting of: at least 60 at % Ni powder and at least one of Cr powder, W powder, V powder, Mo powder, Cu powder, Al powder, Ce powder, YSZ powder, Y powder, Mg powder, and RE powder; the article having a fine and homogeneous grain structure; and having a dominant cube oriented {100}<100> orientation texture; and further having a Curie temperature less than that of pure Ni.

  15. Biaxially textured articles formed by powder metallurgy

    DOEpatents

    Goyal, Amit; Williams, Robert K.; Kroeger, Donald M.

    2005-05-10

    A biaxially textured alloy article having a magnetism less than pure Ni includes a rolled and annealed compacted and sintered powder-metallurgy preform article, the preform article having been formed from a powder mixture selected from the group of mixtures consisting of at least 60 at % Ni powder and at least one of Cr powder, W powder, V powder, Mo powder, Cu powder, Al powder, Ce powder, YSZ powder, Y powder, Mg powder, and RE powder; the article having a fine and homogeneous grain structure; and having a dominant cube oriented {100}<100> orientation texture; and further having a Curie temperature less than that of pure Ni.

  16. Biaxially textured articles formed by power metallurgy

    DOEpatents

    Goyal, Amit; Williams, Robert K.; Kroeger, Donald M.

    2003-08-26

    A biaxially textured alloy article having a magnetism less than pure Ni includes a rolled and annealed compacted and sintered powder-metallurgy preform article, the preform article having been formed from a powder mixture selected from the group of mixtures consisting of: at least 60 at % Ni powder and at least one of Cr powder, W powder, V powder, Mo powder, Cu powder, Al powder, Ce powder, YSZ powder, Y powder, Mg powder, and RE powder; the article having a fine and homogeneous grain structure; and having a dominant cube oriented {100}<100> orientation texture; and further having a Curie temperature less than that of pure Ni.

  17. Biaxially textured articles formed by powder metallurgy

    DOEpatents

    Goyal, Amit; Williams, Robert K.; Kroeger, Donald M.

    2003-08-26

    A biaxially textured alloy article having a magnetism less than pure Ni includes a rolled and annealed compacted and sintered powder-metallurgy preform article, the preform article having been formed from a powder mixture selected from the group of mixtures consisting of: at least 60 at % Ni powder and at least one of Cr powder, W powder, V powder, Mo powder, Cu powder, Al powder, Ce powder, YSZ powder, Y powder, Mg powder, and RE powder; the article having a fine and homogeneous grain structure; and having a dominant cube oriented {100}<100> orientation texture; and further having a Curie temperature less than that of pure Ni.

  18. Biaxially textured articles formed by powder metallurgy

    DOEpatents

    Goyal, Amit; Williams, Robert K.; Kroeger, Donald M.

    2003-08-19

    A biaxially textured alloy article having a magnetism less than pure Ni includes a rolled and annealed compacted and sintered powder-metallurgy preform article, the preform article having been formed from a powder mixture selected from the group of mixtures consisting of: at least 60 at % Ni powder and at least one of Cr powder, W powder, V powder, Mo powder, Cu powder, Al powder, Ce powder, YSZ powder, Y powder, Mg powder, and RE powder; the article having a fine and homogeneous grain structure; and having a dominant cube oriented {100}<100> orientation texture; and further having a Curie temperature less than that of pure Ni.

  19. Biaxially textured articles formed by powder metallurgy

    DOEpatents

    Goyal, Amit; Williams, Robert K.; Kroeger, Donald M.

    2004-09-28

    A biaxially textured alloy article having a magnetism less than pure Ni includes a rolled and annealed compacted and sintered powder-metallurgy preform article, the preform article having been formed from a powder mixture selected from the group of mixtures consisting of: at least 60 at % Ni powder and at least one of Cr powder, W powder, V powder, Mo powder, Cu powder, Al powder, Ce powder, YSZ powder, Y powder, Mg powder, and RE powder; the article having a fine and homogeneous grain structure; and having a dominant cube oriented {100}<100> orientation texture; and further having a Curie temperature less than that of pure Ni.

  20. Biaxially textured articles formed by powder metallurgy

    DOEpatents

    Goyal, Amit; Williams, Robert K.; Kroeger, Donald M.

    2004-09-14

    A biaxially textured alloy article having a magnetism less than pure Ni includes a rolled and annealed compacted and sintered powder-metallurgy preform article, the preform article having been formed from a powder mixture selected from the group of mixtures consisting of: at least 60 at % Ni powder and at least one of Cr powder, W powder, V powder, Mo powder, Cu powder, Al powder, Ce powder, YSZ powder, Y powder, Mg powder, and RE powder; the article having a fine and homogeneous grain structure; and having a dominant cube oriented {100}<100> orientation texture; and further having a Curie temperature less than that of pure Ni.

  1. Biaxially textured articles formed by powder metallurgy

    DOEpatents

    Goyal, Amit; Williams, Robert K.; Kroeger, Donald M.

    2003-07-29

    A biaxially textured alloy article having a magnetism less than pure Ni includes a rolled and annealed compacted and sintered powder-metallurgy preform article, the preform article having been formed from a powder mixture selected from the group of mixtures consisting of: at least 60 at % Ni powder and at least one of Cr powder, W powder, V powder, Mo powder, Cu powder, Al powder, Ce powder, YSZ powder, Y powder, Mg powder, and RE powder; the article having a fine and homogeneous grain structure; and having a dominant cube oriented {100}<100> orientation texture; and further having a Curie temperature less than that of pure Ni.

  2. Biaxially textured articles formed by powder metallurgy

    DOEpatents

    Goval, Amit; Williams, Robert K.; Kroeger, Donald M.

    2005-06-07

    A biaxially textured alloy article having a magnetism less than pure Ni includes a rolled and annealed compacted and sintered powder-metallurgy preform article, the preform article having been formed from a powder mixture selected from the group of mixtures consisting of: at least 60 at % Ni powder and at least one of Cr powder, W powder, V powder, Mo powder, Cu powder, Al powder, Ce powder, YSZ powder, Y powder, Mg powder, and RE powder; the article having a fine and homogeneous grain structure; and having a dominant cube oriented {100}<100> orientation texture; and further having a Curie temperature less than that of pure Ni.

  3. Evaluation of tantalum 316 stainless steel transition joints

    NASA Technical Reports Server (NTRS)

    Stoner, D. R.

    1972-01-01

    Tubular transition joints providing a metallurgically bonded connection between tantalum and 316 stainless steel pipe sections were comparatively evaluated for durability under thermal cycling conditions approximating the operation of a SNAP-8 mercury boiler. Both coextruded and vacuum brazed transition joints of 50mm (2 inch) diameter were tested by thermal cycling 100 times between 730 C and 120 C(1350 F and 250 F) in a high vacuum environment. The twelve evaluated transition joints survived the full test sequence without developing leaks, although liquid penetrant bond line indications eventually developed in all specimens. The brazed transition joints exhibited the best dimensional stability and bond line durability.

  4. LUNAR MODULE TEST ARTICLE [LTA] [2R] IS MOVED FOR MATING TO LUNAR MODULE ADAPTER

    NASA Technical Reports Server (NTRS)

    1967-01-01

    The Lunar Module Test Article [LTA] 2R, for the second Saturn V mission, is being moved from the low bay of the Manned Spacecraft Operations Building for mating with the spacecraft Lunar Module Adapter. The second Saturn V [502], except for a different lunar return trajectory, will be a repeat of the Apollo 4 unmanned Earth orbital flight of a high apogee for systems testing using several propulsion system burns and a heat shield test at lunar re-entry speed.

  5. Orion EFT-1 Heat Shield move from LASF to VAB for Ground Test Article Integration

    NASA Image and Video Library

    2017-04-26

    The heat shield for Exploration Flight Test-1 is transferred from the Orion Program to the Ground Systems Development and Operations Program, Landing and Recovery Operations to be integrated with the Ground Test Article to be utilized for future Underway Recovery Testing. After transport from the Launch Abort System Facility (LASF) to the Vehicle Assembly Building (VAB), the heat shield is lifted off of the transport truck and placed onto foam pads (dunnage) for inspection in Highbay 2 of the VAB.

  6. 24 CFR 3280.605 - Joints and connections.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... watertight for the pressures required under testing procedures. (1) Assembling of pipe. All joints and... or welding sockets of each fitting. Pipe threads and slip joints shall not be wrapped with string...

  7. Rapid Analyses of Polyetheretherketone Wear Characteristics by Accelerated Wear Testing with Microfabricated Surfaces for Artificial Joint Systems

    PubMed Central

    Kuo, Chien-Wei

    2017-01-01

    Wear particle-induced biological responses are the major factors resulting in the loosening and then failure of total joint arthroplasties. It is feasible to improve the lubrication and reduce the wear of artificial joint system. Polyetheretherketone (PEEK) is considered as a potential bearing material due to its mechanical characteristics of resistance to fatigue strain. The PEEK wear particles have been indicated to be involved in biological responses in vitro, and further studies regarding the wear phenomena and wear particle generation are needed. In this study, we have established an accelerated wear testing system with microfabricated surfaces. Various contact pressures and lubricants have been utilized in the accelerated wear tests. Our results showed that increasing contact pressure resulted in an increase of wear particle sizes and wear rate, and the size of PEEK wear particles can be controlled by the feature size of microfabricated surfaces. These results provided the information rapidly about factors that affect the morphology and amount of PEEK wear particles and can be applied in the future for application of PEEK on the biological articulation system. PMID:29230411

  8. Rapid Analyses of Polyetheretherketone Wear Characteristics by Accelerated Wear Testing with Microfabricated Surfaces for Artificial Joint Systems.

    PubMed

    Su, Chen-Ying; Kuo, Chien-Wei; Fang, Hsu-Wei

    2017-01-01

    Wear particle-induced biological responses are the major factors resulting in the loosening and then failure of total joint arthroplasties. It is feasible to improve the lubrication and reduce the wear of artificial joint system. Polyetheretherketone (PEEK) is considered as a potential bearing material due to its mechanical characteristics of resistance to fatigue strain. The PEEK wear particles have been indicated to be involved in biological responses in vitro, and further studies regarding the wear phenomena and wear particle generation are needed. In this study, we have established an accelerated wear testing system with microfabricated surfaces. Various contact pressures and lubricants have been utilized in the accelerated wear tests. Our results showed that increasing contact pressure resulted in an increase of wear particle sizes and wear rate, and the size of PEEK wear particles can be controlled by the feature size of microfabricated surfaces. These results provided the information rapidly about factors that affect the morphology and amount of PEEK wear particles and can be applied in the future for application of PEEK on the biological articulation system.

  9. Manned remote work station development article. Volume 3: Development test plan. Appendix A: Manufacturing requirements/schedule

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The tests and procedures for the manned remote work station (MRWS) open cherry picker (OCP) development test article (DTA) are described to validate systems requirements and performance specifications. A development test program is outlined to evaluate key design issues and man/machine interfaces when the MRWS OCP is used in a shuttle support role of satellite servicing and in orbit construction of large structures.

  10. Dynamic Analyses Including Joints Of Truss Structures

    NASA Technical Reports Server (NTRS)

    Belvin, W. Keith

    1991-01-01

    Method for mathematically modeling joints to assess influences of joints on dynamic response of truss structures developed in study. Only structures with low-frequency oscillations considered; only Coulomb friction and viscous damping included in analysis. Focus of effort to obtain finite-element mathematical models of joints exhibiting load-vs.-deflection behavior similar to measured load-vs.-deflection behavior of real joints. Experiments performed to determine stiffness and damping nonlinearities typical of joint hardware. Algorithm for computing coefficients of analytical joint models based on test data developed to enable study of linear and nonlinear effects of joints on global structural response. Besides intended application to large space structures, applications in nonaerospace community include ground-based antennas and earthquake-resistant steel-framed buildings.

  11. Joint model for a diagnostic test without a gold standard in the presence of a dependent terminal event.

    PubMed

    Luo, Sheng; Su, Xiao; DeSantis, Stacia M; Huang, Xuelin; Yi, Min; Hunt, Kelly K

    2014-07-10

    Breast cancer patients after breast conservation therapy often develop ipsilateral breast tumor relapse (IBTR), whose classification (true local recurrence versus new ipsilateral primary tumor) is subject to error, and there is no available gold standard. Some patients may die because of breast cancer before IBTR develops. Because this terminal event may be related to the individual patient's unobserved disease status and time to IBTR, the terminal mechanism is non-ignorable. This article presents a joint analysis framework to model the binomial regression with misclassified binary outcome and the correlated time to IBTR, subject to a dependent terminal event and in the absence of a gold standard. Shared random effects are used to link together two survival times. The proposed approach is evaluated by a simulation study and is applied to a breast cancer data set consisting of 4477 breast cancer patients. The proposed joint model can be conveniently fit using adaptive Gaussian quadrature tools implemented in SAS 9.3 (SAS Institute Inc., Cary, NC, USA) procedure NLMIXED. Copyright © 2014 John Wiley & Sons, Ltd.

  12. Conarticular congruence of the hominoid subtalar joint complex with implications for joint function in Plio-Pleistocene hominins.

    PubMed

    Prang, Thomas C

    2016-07-01

    The purpose of this study is to test the hypothesis that conarticular surfaces areas and curvatures are correlates of mobility at the hominoid talocalcaneal and talonavicular joints. Articular surface areas and curvatures of the talonavicular, anterior talocalcaneal, and posterior talocalcaneal joints were quantified using a total of 425 three-dimensional surface models of extant hominoid and fossil hominin tali, calcanei, and naviculars. Quadric surface fitting was used to calculate curvatures, pairwise comparisons were used to evaluate statistical differences between taxa, and regression was used to test for the effects of allometry. Pairwise comparisons show that the distributions of values for joint curvature indices follow the predicted arboreal-terrestrial morphocline in hominoid primates with no effect of body mass (PGLS p > 0.05). OH 8 (Homo habilis) and LB 1 (Homo floresiensis) can be accommodated within the range of human variation for the talonavicular joint, whereas MH2 (Australopithecus sediba) falls within the ranges of variation for Pan troglodytes and Gorilla gorilla in measures of posterior talocalcaneal joint congruity. Joint curvature indices are better discriminators than joint surface area indices, which may reflect a greater contribution of rotation, rather than translation, to joint movement in plantigrade taxa due to discrepancies in conarticular congruence and the "convex-concave" rule. The pattern of joint congruence in Au. sediba contributes to other data on the foot and ankle suggesting that the lateral side of the foot was more mobile than the medial side, which is consistent with suggestions of increased medial weight transfer associated with hyperpronation. Am J Phys Anthropol 160:446-457, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  13. 16 CFR 1109.13 - Component part testing for phthalates in children's toys and child care articles.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 2 2012-01-01 2012-01-01 false Component part testing for phthalates in..., Component Parts, and Chemicals § 1109.13 Component part testing for phthalates in children's toys and child... children's toy or child care article for phthalate content provided that the requirements in § 1109.5 are...

  14. 16 CFR 1109.13 - Component part testing for phthalates in children's toys and child care articles.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 2 2014-01-01 2014-01-01 false Component part testing for phthalates in..., Component Parts, and Chemicals § 1109.13 Component part testing for phthalates in children's toys and child... children's toy or child care article for phthalate content provided that the requirements in § 1109.5 are...

  15. Integrated System Test Approaches for the NASA Ares I Crew Launch Vehicle

    NASA Technical Reports Server (NTRS)

    Cockrell, Charles

    2008-01-01

    NASA is maturing test and evaluation plans leading to flight readiness of the Ares I crew launch vehicle. Key development, qualification, and verification tests are planned . Upper stage engine sea-level and altitude testing. First stage development and qualification motors. Upper stage structural and thermal development and qualification test articles. Main Propulsion Test Article (MPTA). Upper stage green run testing. Integrated Vehicle Ground Vibration Testing (IVGVT). Aerodynamic characterization testing. Test and evaluation supports initial validation flights (Ares I-Y and Orion 1) and design certification.

  16. Minimally invasive arthrodesis for chronic sacroiliac joint dysfunction using the SImmetry SI Joint Fusion system

    PubMed Central

    Miller, Larry E; Block, Jon E

    2014-01-01

    Chronic sacroiliac (SI) joint-related low back pain (LBP) is a common, yet under-diagnosed and undertreated condition due to difficulties in accurate diagnosis and highly variable treatment practices. In patients with debilitating SI-related LBP for at least 6 months duration who have failed conservative management, arthrodesis is a viable option. The SImmetry® SI Joint Fusion System is a novel therapy for SI joint fusion, not just fixation, which utilizes a minimally invasive surgical approach, instrumented fixation for immediate stability, and joint preparation with bone grafting for a secure construct in the long term. The purpose of this report is to describe the minimally invasive SI Joint Fusion System, including patient selection criteria, implant characteristics, surgical technique, postoperative recovery, and biomechanical testing results. Advantages and limitations of this system will be discussed. PMID:24851059

  17. Sacroiliac joint tuberculosis

    PubMed Central

    Govender, S.

    2006-01-01

    Infections of the sacroiliac joint are uncommon and the diagnosis is usually delayed. In a retrospective study, 17 patients who had been treated for tuberculosis sacroiliitis between 1994 and 2004 were reviewed. Two patients were excluded due to a short follow-up (less than 2 years). Low back pain and difficulty in walking were the most common presenting features. Two patients presented with a buttock abscess and spondylitis of the lumbar spine was noted in two patients. The Gaenslen’s and FABER (flexion, abduction and external rotation) tests were positive in all patients. Radiological changes included loss of cortical margins with erosion of the joints. An open biopsy and curettage was performed in all patients; histology revealed chronic infection and acid-fast bacilli were isolated in nine patients. Antituberculous (TB) medication was administered for 18 months and the follow-up ranged from 3 to 10 years (mean: 5 years). The sacroiliac joint fused spontaneously within 2 years. Although all patients had mild discomfort in the lower back following treatment they had no difficulty in walking. Sacroiliac joint infection must be included in the differential diagnosis of lower back pain and meticulous history and clinical evaluation of the joint are essential. PMID:16673102

  18. Localized cervical facet joint kinematics under physiological and whiplash loading.

    PubMed

    Stemper, Brian D; Yoganandan, Narayan; Gennarelli, Thomas A; Pintar, Frank A

    2005-12-01

    Although facet joints have been implicated in the whiplash injury mechanism, no investigators have determined the degree to which joint motions in whiplash are nonphysiological. The purpose of this investigation was to quantify the correlation between facet joint and segmental motions under physiological and whiplash loading. Human cadaveric cervical spine specimens were exercise tested under physiological extension loading, and intact human head-neck complexes were exercise tested under whiplash loading to correlate the localized component motions of the C4-5 facet joint with segmental extension. Facet joint shear and distraction kinematics demonstrated a linear correlation with segmental extension under both loading modes. Facet joints responded differently to whiplash and physiological loading, with significantly increased kinematics for the same-segmental angulation. The limitations of this study include removal of superficial musculature and the limited sample size for physiological testing. The presence of increased facet joint motions indicated that synovial joint soft-tissue components (that is, synovial membrane and capsular ligament) sustain increased distortion that may subject these tissues to a greater likelihood of injury. This finding is supported by clinical investigations in which lower cervical facet joint injury resulted in similar pain patterns due to the most commonly reported whiplash symptoms.

  19. High-impact articles in hand surgery.

    PubMed

    Eberlin, Kyle R; Labow, Brian I; Upton, Joseph; Taghinia, Amir H

    2012-06-01

    There have been few attempts to identify classic papers within the hand surgery literature. This study used citation analysis to identify and characterize the top 50 highly cited hand surgery articles published in six peer-reviewed journals. The 50 most highly cited hand surgery articles were identified in the Journal of Bone and Joint Surgery (JBJS) American, JBJS British, Plastic and Reconstructive Surgery, Journal of Hand Surgery (JHS) American, JHS British/European, and Hand. Articles were evaluated for citations per year, surgical/anatomical topic, and type of study. Clinical studies were further sub-categorized by level of evidence. The distribution of topics was compared with all indexed hand surgery articles. The educational relevance was assessed via comparison with lists of "classic" papers. The most common subjects were distal radius fracture, carpal tunnel syndrome, and flexor tendon repair. There was moderate correlation between the distribution of these topics and all indexed hand surgery articles (rho = 0.71). There were 31 clinical studies, of which 16 were therapeutic, ten were prognostic, and five were diagnostic. These articles assessed the outcomes of an intervention, described an anatomical/functional observation, introduced an innovation, presented a discovery/classification, or validated a questionnaire. There were only three randomized trials. Using citations per year to control for the influence of time since publication, 36 articles were consistently highly cited. Twenty-three articles were on Stern's Selected Readings in Hand Surgery, considered important in education. The top 50 highly cited articles in hand surgery reflect the most common clinical, scientific, and educational efforts of the field.

  20. Ligamentous and capsular injuries to the metacarpophalangeal joints of the hand.

    PubMed

    Shah, Smiresh Suresh; Techy, Fernando; Mejia, Alfonso; Gonzalez, Mark H

    2012-01-01

    The mechanism of dorsal dislocation of the metacarpophalangeal (MCP) joint is with forced hyperextension of the joint and the main structure injured is the volar plate. A simple dislocation can be reduced by closed means whereas a complex dislocation cannot. Care must be taken not to put traction across the joint, which may cause the volar plate to slip into the joint, converting a simple dislocation into a complex dislocation. Volar dislocations are rare and mainly treated nonoperatively. Sagittal band injuries can be treated with extension splinting or surgical management with direct repair or reconstruction. A locked MCP joint can usually be treated with closed manipulation. This article discusses these injuries and management options.

  1. Design/Analysis of the JWST ISIM Bonded Joints for Survivability at Cryogenic Temperatures

    NASA Technical Reports Server (NTRS)

    Bartoszyk, Andrew; Johnston, John; Kaprielian, Charles; Kuhn, Jonathan; Kunt, Cengiz; Rodini,Benjamin; Young, Daniel

    1990-01-01

    A major design and analysis challenge for the JWST ISIM structure is thermal survivability of metal/composite bonded joints below the cryogenic temperature of 30K (-405 F). Current bonded joint concepts include internal invar plug fittings, external saddle titanium/invar fittings and composite gusset/clip joints all bonded to M55J/954-6 and T300/954-6 hybrid composite tubes (75mm square). Analytical experience and design work done on metal/composite bonded joints at temperatures below that of liquid nitrogen are limited and important analysis tools, material properties, and failure criteria for composites at cryogenic temperatures are sparse in the literature. Increasing this challenge is the difficulty in testing for these required tools and properties at cryogenic temperatures. To gain confidence in analyzing and designing the ISIM joints, a comprehensive joint development test program has been planned and is currently running. The test program is designed to produce required analytical tools and develop a composite failure criterion for bonded joint strengths at cryogenic temperatures. Finite element analysis is used to design simple test coupons that simulate anticipated stress states in the flight joints; subsequently the test results are used to correlate the analysis technique for the final design of the bonded joints. In this work, we present an overview of the analysis and test methodology, current results, and working joint designs based on developed techniques and properties.

  2. Investigation of Super*Zip separation joint

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.; Schimmel, Morry L.

    1988-01-01

    An investigation to determine the most likely cause of two failures of five tests on 79 inch diameter Lockheed Super*Zip spacecraft separation joints being used for the development of a Shuttle/Centaur propulsion system. This joint utilizes an explosively expanded tube to fracture surrounding prenotched aluminum plates to achieve planar separation. A test method was developed and more than 300 tests firings were made to provide an understanding of severance mechanisms and the functional performance effects of system variables. An approach for defining functional margin was developed, and specific recommendations were made for improving existing and future systems.

  3. The sacroiliac joint: anatomy, physiology and clinical significance.

    PubMed

    Forst, Stacy L; Wheeler, Michael T; Fortin, Joseph D; Vilensky, Joel A

    2006-01-01

    The sacroiliac joint (SIJ) is a putative source of low back pain. The objective of this article is to provide clinicians with a concise review of SIJ structure and function, diagnostic indicators of SIJ-mediated pain, and therapeutic considerations. The SIJ is a true diarthrodial joint with unique characteristics not typically found in other diarthrodial joints. The joint differs with others in that it has fibrocartilage in addition to hyaline cartilage, there is discontinuity of the posterior capsule, and articular surfaces have many ridges and depressions. The sacroiliac joint is well innervated. Histological analysis of the sacroiliac joint has verified the presence of nerve fibers within the joint capsule and adjoining ligaments. It has been variously described that the sacroiliac joint receives its innervation from the ventral rami of L4 and L5, the superior gluteal nerve, and the dorsal rami of L5, S1, and S2, or that it is almost exclusively derived from the sacral dorsal rami. Even though the sacroiliac joint is a known putative source of low back and lower extremity pain, there are few findings that are pathognomonic of sacroiliac joint pain. The controlled diagnostic blocks utilizing the International Association for the Study of Pain (IASP) criteria demonstrated the prevalence of pain of sacroiliac joint origin in 19% to 30% of the patients suspected to have sacroiliac joint pain. Conservative management includes manual medicine techniques, pelvic stabilization exercises to allow dynamic postural control, and muscle balancing of the trunk and lower extremities. Interventional treatments include sacroiliac joint, intra-articular joint injections, radiofrequency neurotomy, prolotherapy, cryotherapy, and surgical treatment. The evidence for intra-articular injections and radiofrequency neurotomy has been shown to be limited in managing sacroiliac joint pain.

  4. Surgical Approaches to the Proximal Interphalangeal Joint.

    PubMed

    Cheah, Andre Eu-Jin; Yao, Jeffrey

    2016-02-01

    The proximal interphalangeal (PIP) joint may be affected by many conditions such as arthropathy, fractures, dislocations, and malunions. Whereas some of these conditions may be treated nonsurgically, many require open surgical intervention. Open interventions include implant arthroplasty or arthrodesis for arthropathy, open reduction internal fixation, or hemi-hamate arthroplasty for dorsal fracture-dislocations. Volar plate arthroplasty and corrective osteotomy for malunion about the PIP joint are also surgeries that may be required. The traditional approach to the PIP joint has been dorsal, which damages the delicate extensor apparatus with subsequent development of an extensor lag. This has led surgeons to explore volar and lateral approaches to the PIP joint. In this article, we describe each of these surgical approaches, discuss their advantages and disadvantages, and provide some guidance on which approach to choose based on the surgery that is to be performed. Copyright © 2016 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  5. Solar Alpha Rotary Joint (SARJ) Lubrication Interval Test and Evaluation (LITE). Post-Test Grease Analysis

    NASA Technical Reports Server (NTRS)

    Golden, Johnny L.; Martinez, James E.; Devivar, Rodrigo V.

    2015-01-01

    The Solar Alpha Rotary Joint (SARJ) is a mechanism of the International Space Station (ISS) that orients the solar power generating arrays toward the sun as the ISS orbits our planet. The orientation with the sun must be maintained to fully charge the ISS batteries and maintain all the other ISS electrical systems operating properly. In 2007, just a few months after full deployment, the starboard SARJ developed anomalies that warranted a full investigation including ISS Extravehicular Activity (EVA). The EVA uncovered unexpected debris that was due to degradation of a nitride layer on the SARJ bearing race. ISS personnel identified the failure root-cause and applied an aerospace grease to lubricate the area associated with the anomaly. The corrective action allowed the starboard SARJ to continue operating within the specified engineering parameters. The SARJ LITE (Lubrication Interval Test and Evaluation) program was initiated by NASA, Lockheed Martin, and Boeing to simulate the operation of the ISS SARJ for an extended time. The hardware was designed to test and evaluate the exact material components used aboard the ISS SARJ, but in a controlled area where engineers could continuously monitor the performance. After running the SARJ LITE test for an equivalent of 36+ years of continuous use, the test was opened to evaluate the metallography and lubrication. We have sampled the SARJ LITE rollers and plate to fully assess the grease used for lubrication. Chemical and thermal analysis of these samples has generated information that has allowed us to assess the location, migration, and current condition of the grease. The collective information will be key toward understanding and circumventing any performance deviations involving the ISS SARJ in the years to come.

  6. Working at a Joint-Use Library

    ERIC Educational Resources Information Center

    Robinson, Carla

    2007-01-01

    The St. Lucie West Library, also known as the FAU Treasure Coast Campus Library, is a joint-use library facility, with Florida Atlantic University partnering with Indian River Community College and the St. Lucie County (FL) Library System. This article will discuss the circulation, course reserves, interlibrary loan, and collection management…

  7. Recent Flight Test Results of the Joint CIAM-NASA Mach 6.5 Scramjet Flight Program

    NASA Technical Reports Server (NTRS)

    Roudakov, Alexander S.; Semenov, Vyacheslav L.; Hicks, John W.

    1998-01-01

    Under a contract with NASA, a joint Central Institute of Aviation Motors (CIAM) and NASA team recently conducted the fourth flight test of a dual-mode scramjet aboard the CIAM Hypersonic Flying Laboratory, 'Kholod'. With an aim test Mach 6.5 objective, the successful launch was conducted at the Sary Shagan test range in central Kazakstan on February 12, 1998. Ground-launch, rocket boosted by a modified Russian SA5 missile, the redesigned scramjet was accelerated to a new maximum velocity greater than Mach 6.4. This launch allowed for the measurement of the fully supersonic combustion mode under actual flight conditions. The primary program objective was the flight-to-ground correlation of measured data with preflight analysis and wind-tunnel tests in Russia and potentially in the United States. This paper describes the development and objectives of the program as well as the technical details of the scramjet and SA5 redesign to achieve the Mach 6.5 aim test condition. An overview of the launch operation is also given. Finally, preliminary flight test results are presented and discussed.

  8. Biomechanics of unilateral and bilateral sacroiliac joint stabilization: laboratory investigation.

    PubMed

    Lindsey, Derek P; Parrish, Robin; Gundanna, Mukund; Leasure, Jeremi; Yerby, Scott A; Kondrashov, Dimitriy

    2018-03-01

    OBJECTIVE Bilateral symptoms have been reported in 8%-35% of patients with sacroiliac (SI) joint dysfunction. Stabilization of a single SI joint may significantly alter the stresses on the contralateral SI joint. If the contralateral SI joint stresses are significantly increased, degeneration may occur; alternatively, if the stresses are significantly reduced, bilateral stabilization may be unnecessary for patients with bilateral symptoms. The biomechanical effects of 1) unilateral stabilization on the contralateral SI joint and 2) bilateral stabilization on both SI joints are currently unknown. The objectives of this study were to characterize bilateral SI joint range of motion (ROM) and evaluate and compare the biomechanical effects of unilateral and bilateral implant placement for SI joint fusion. METHODS A lumbopelvic model (L5-pelvis) was used to test the ROM of both SI joints in 8 cadavers. A single-leg stance setup was used to load the lumbar spine and measure the ROM of each SI joint in flexion-extension, lateral bending, and axial rotation. Both joints were tested 1) while intact, 2) after unilateral stabilization, and 3) after bilateral stabilization. Stabilization consisted of lateral transiliac placement of 3 triangular titanium plasma-sprayed (TPS) implants. RESULTS Intact testing showed that during single-leg stance the contralateral SI joint had less ROM in flexion-extension (27%), lateral bending (32%), and axial rotation (69%) than the loaded joint. Unilateral stabilization resulted in significant reduction of flexion-extension ROM (46%) on the treated side; no significant ROM changes were observed for the nontreated side. Bilateral stabilization resulted in significant reduction of flexion-extension ROM of the primary (45%) and secondary (75%) SI joints. CONCLUSIONS This study demonstrated that during single-leg loading the ROMs for the stance (loaded) and swing (unloaded) SI joints are significantly different. Unilateral stabilization for SI

  9. Initial Testing for the Recommendation of Improved Gas Metal Arc Welding Procedures for HY-80 Steel Plate Butt Joints at Norfolk Naval Shipyard

    DTIC Science & Technology

    2015-12-01

    is unlimited 12b. DISTRIBUTION CODE 13. ABSTRACT (maximum 200 words) Hull cut welding proficiency is an essential skill maintained by personnel...at naval shipyards. This thesis explores arc weld theory to develop ideal submarine hull butt joint designs and recommends preliminary testing to...shipboard hull welding applications, theoretically. Butt joint samples were created using HY-80 steel plate so that the following comparisons could

  10. Critical joints in large composite aircraft structure

    NASA Technical Reports Server (NTRS)

    Nelson, W. D.; Bunin, B. L.; Hart-Smith, L. J.

    1983-01-01

    A program was conducted at Douglas Aircraft Company to develop the technology for critical structural joints of composite wing structure that meets design requirements for a 1990 commercial transport aircraft. The prime objective of the program was to demonstrate the ability to reliably predict the strength of large bolted composite joints. Ancillary testing of 180 specimens generated data on strength and load-deflection characteristics which provided input to the joint analysis. Load-sharing between fasteners in multirow bolted joints was computed by the nonlinear analysis program A4EJ. This program was used to predict strengths of 20 additional large subcomponents representing strips from a wing root chordwise splice. In most cases, the predictions were accurate to within a few percent of the test results. In some cases, the observed mode of failure was different than anticipated. The highlight of the subcomponent testing was the consistent ability to achieve gross-section failure strains close to 0.005. That represents a considerable improvement over the state of the art.

  11. Experimental studies of glued Aluminum-glass joints

    NASA Astrophysics Data System (ADS)

    Ligaj, B.; Wirwicki, M.; Karolewska, K.; Jasińska, A.

    2018-04-01

    Glued steel-glass or aluminum-glass joints are to be found, among other things, in vehicles (cars, buses, trains, trams) as windscreen assembly pieces for the supporting structure. For the purposes of the experiments, samples were made in which the top beam was made of the AW-2017A aluminum alloy and the bottom beam was made of thermally reinforced soda-lime glass whereas the glued joints were made of one-component polyurethane glue Körapur 175. The tests were performed under four-point bending conditions at monotonic incremental bending moment values on the Instron 5965 durability machine. The experimental study of the durability of glued joints under four-point bending conditions with the monotonic incremental bending moment allows to determine the values of stresses, whose value is related to initiation of damage of the tested joint.

  12. Recommended Strain Gage Application Procedures for Various Langley Research Center Balances and Test Articles

    NASA Technical Reports Server (NTRS)

    Moore, Thomas C., Sr.

    1997-01-01

    The NASA Langley Research Center uses more than 10000 strain gages per year in supporting its various research programs. The character of the testing at LaRC is such that the types of strain gage installations, the materials they are applied to, and the test environments encountered, require many varied approaches for installing strain gages. These installations must be accomplished in the most technically discerning and appropriate manner. This technical memorandum is offered as an assisting guide in helping the strain gage user to determine the appropriate approach for a given strain gage application requirement. Specifically, this document offers detailed recommendations for strain gaging the following: LaRC-Designed balances, LARC custom transducers, certain composite materials and alloys, high-temperature test articles, and selected non-typical or unique materials or test conditions.

  13. Copula Models for Sociology: Measures of Dependence and Probabilities for Joint Distributions

    ERIC Educational Resources Information Center

    Vuolo, Mike

    2017-01-01

    Often in sociology, researchers are confronted with nonnormal variables whose joint distribution they wish to explore. Yet, assumptions of common measures of dependence can fail or estimating such dependence is computationally intensive. This article presents the copula method for modeling the joint distribution of two random variables, including…

  14. Elite Female Basketball Players' Body-Weight Neuromuscular Training and Performance on the Y-Balance Test.

    PubMed

    Benis, Roberto; Bonato, Matteo; La Torre, Antonio La

    2016-09-01

    Neuromuscular training enhances unconscious motor responses by stimulating both the afferent signals and central mechanisms responsible for dynamic joint control. Dynamic joint-control training is a vital component of injury-prevention programs. To investigate the effects of body-weight neuromuscular training on Y-Balance Test (YBT) performance and postural control in female basketball players. Randomized controlled clinical trial. Basketball practice sessions. A total of 28 healthy elite female basketball players were randomly assigned to an experimental (n = 14) or a control group (n = 14). Before their regular practice sessions, the experimental group warmed up with body-weight neuromuscular exercises and the control group with standard tactical-technical exercises twice weekly for 8 weeks. Anterior-, posteromedial-, and posterolateral-reach and composite YBT scores were measured before and after 8 weeks of training. Improvement over baseline scores was noted in the posteromedial (right = 86.5 ± 4.5 cm versus 89.6 ± 2.2 cm, +3.5%, P = .049; left = 85.5 ± 4.3 cm versus 90.2 ± 2.7 cm, +5.5%, P = .038)- and posterolateral (right = 90.7 ± 3.6 cm versus 94.0 ± 2.7 cm, +3.6%, P = .016; left = 90.9 ± 3.5 cm versus 94.2 ± 2.6 cm, +3.6%, P = .011)-reach directions and in the composite YBT scores (right = 88.6% ± 3.2% versus 94.0% ± 1.8%, +5.4%, P = .0004; left = 89.2% ± 3.2% versus 94.5% ± 3.0%, +5.8%, P = .001) of the experimental group. No differences in anterior reach were detected in either group. Differences were noted in postintervention scores for posteromedial reach (right = 89.6 ± 2.2 cm versus 84.3 ± 4.4 cm, +4.1%, P = .005; left = 94.2 ± 2.6 cm versus 84.8 ± 4.4 cm, +10%, P = .003) and composite scores (right = 94.0% ± 1.8% versus 87.3% ± 2.0%, +7.1%, P = .003; left = 94.8% ± 3.0% versus 87.9% ± 3.4%, +7.3%, P < .0001) between the experimental and control groups. Body-weight neuromuscular training improved postural control and lower limb

  15. Development of ASTM Standard for SiC-SiC Joint Testing Final Scientific/Technical Report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jacobsen, George; Back, Christina

    2015-10-30

    As the nuclear industry moves to advanced ceramic based materials for cladding and core structural materials for a variety of advanced reactors, new standards and test methods are required for material development and licensing purposes. For example, General Atomics (GA) is actively developing silicon carbide (SiC) based composite cladding (SiC-SiC) for its Energy Multiplier Module (EM2), a high efficiency gas cooled fast reactor. Through DOE funding via the advanced reactor concept program, GA developed a new test method for the nominal joint strength of an endplug sealed to advanced ceramic tubes, Fig. 1-1, at ambient and elevated temperatures called themore » endplug pushout (EPPO) test. This test utilizes widely available universal mechanical testers coupled with clam shell heaters, and specimen size is relatively small, making it a viable post irradiation test method. The culmination of this effort was a draft of an ASTM test standard that will be submitted for approval to the ASTM C28 ceramic committee. Once the standard has been vetted by the ceramics test community, an industry wide standard methodology to test joined tubular ceramic components will be available for the entire nuclear materials community.« less

  16. Experimental measurement and modeling analysis on mechanical properties of incudostapedial joint

    PubMed Central

    Zhang, Xiangming

    2011-01-01

    The incudostapedial (IS) joint between the incus and stapes is a synovial joint consisting of joint capsule, cartilage, and synovial fluid. The mechanical properties of the IS joint directly affect the middle ear transfer function for sound transmission. However, due to the complexity and small size of the joint, the mechanical properties of the IS joint have not been reported in the literature. In this paper, we report our current study on mechanical properties of human IS joint using both experimental measurement and finite element (FE) modeling analysis. Eight IS joint samples with the incus and stapes attached were harvested from human cadaver temporal bones. Tension, compression, stress relaxation and failure tests were performed on those samples in a micro-material testing system. An analytical approach with the hyperelastic Ogden model and a 3D FE model of the IS joint including the cartilage, joint capsule, and synovial fluid were employed to derive mechanical parameters of the IS joint. The comparison of measurements and modeling results reveals the relationship between the mechanical properties and structure of the IS joint. PMID:21061141

  17. Experimental measurement and modeling analysis on mechanical properties of incudostapedial joint.

    PubMed

    Zhang, Xiangming; Gan, Rong Z

    2011-10-01

    The incudostapedial (IS) joint between the incus and stapes is a synovial joint consisting of joint capsule, cartilage, and synovial fluid. The mechanical properties of the IS joint directly affect the middle ear transfer function for sound transmission. However, due to the complexity and small size of the joint, the mechanical properties of the IS joint have not been reported in the literature. In this paper, we report our current study on mechanical properties of human IS joint using both experimental measurement and finite element (FE) modeling analysis. Eight IS joint samples with the incus and stapes attached were harvested from human cadaver temporal bones. Tension, compression, stress relaxation and failure tests were performed on those samples in a micro-material testing system. An analytical approach with the hyperelastic Ogden model and a 3D FE model of the IS joint including the cartilage, joint capsule, and synovial fluid were employed to derive mechanical parameters of the IS joint. The comparison of measurements and modeling results reveals the relationship between the mechanical properties and structure of the IS joint.

  18. Flexor bias of joint position in humans during spaceflight

    NASA Technical Reports Server (NTRS)

    McCall, G. E.; Goulet, C.; Boorman, G. I.; Roy, R. R.; Edgerton, V. R.

    2003-01-01

    The ability to estimate ankle and elbow joint position was tested before, during, and after a 17-day spaceflight. Subjects estimated targeted joint angles during isovelocity (IsoV) joint movements with agonist muscle groups either active or relaxed. These movements included elbow extension (EE) and elbow flexion (EF), and plantarflexion (PF) and dorsiflexion (DF) of the ankle. Subjects also estimated these joint positions while moving the dynamometer at their chosen (variable) velocity (VarV) during EE and PF. For IsoV tests, no differences were observed between active and passive movements for either the ankle or elbow. Compared with those of pre-flight test days, estimates of targeted elbow joint angles were approximately 5 degrees to 15 degrees more flexed in-flight, and returned toward the pre-flight values during recovery. The spaceflight effects for the ankle were inconsistent and less prevalent than those for the elbow. The VarV PF test condition for the 120 degrees target angle at the ankle exhibited approximately 5 degrees to 7 degrees more DF target angle estimates in-flight compared with those pre- or post-flight. In contrast, during IsoV PF there was a tendency for ankle estimates to be approximately 2 degrees to 3 degrees more PF after 2-3 days exposure to spaceflight. These data indicate that during spaceflight the perception of elbow extension is greater than actuality, and are consistent with the interpretation that microgravity induced a flexor bias in the estimation of the actual elbow joint position. Moreover, these effects in joint proprioception during spaceflight were observed in individual isolated single-joint movements during tasks in which vestibular function in maintaining posture were minimal.

  19. Flexor bias of joint position in humans during spaceflight.

    PubMed

    McCall, G E; Goulet, C; Boorman, G I; Roy, R R; Edgerton, V R

    2003-09-01

    The ability to estimate ankle and elbow joint position was tested before, during, and after a 17-day spaceflight. Subjects estimated targeted joint angles during isovelocity (IsoV) joint movements with agonist muscle groups either active or relaxed. These movements included elbow extension (EE) and elbow flexion (EF), and plantarflexion (PF) and dorsiflexion (DF) of the ankle. Subjects also estimated these joint positions while moving the dynamometer at their chosen (variable) velocity (VarV) during EE and PF. For IsoV tests, no differences were observed between active and passive movements for either the ankle or elbow. Compared with those of pre-flight test days, estimates of targeted elbow joint angles were approximately 5 degrees to 15 degrees more flexed in-flight, and returned toward the pre-flight values during recovery. The spaceflight effects for the ankle were inconsistent and less prevalent than those for the elbow. The VarV PF test condition for the 120 degrees target angle at the ankle exhibited approximately 5 degrees to 7 degrees more DF target angle estimates in-flight compared with those pre- or post-flight. In contrast, during IsoV PF there was a tendency for ankle estimates to be approximately 2 degrees to 3 degrees more PF after 2-3 days exposure to spaceflight. These data indicate that during spaceflight the perception of elbow extension is greater than actuality, and are consistent with the interpretation that microgravity induced a flexor bias in the estimation of the actual elbow joint position. Moreover, these effects in joint proprioception during spaceflight were observed in individual isolated single-joint movements during tasks in which vestibular function in maintaining posture were minimal.

  20. Design/analysis of the JWST ISIM bonded joints for survivability at cryogenic temperatures

    NASA Astrophysics Data System (ADS)

    Bartoszyk, Andrew; Johnston, John; Kaprielian, Charles; Kuhn, Jonathan; Kunt, Cengiz; Rodini, Benjamin; Young, Daniel

    2005-08-01

    A major design and analysis challenge for the JWST ISIM structure is thermal survivability of metal/composite adhesively bonded joints at the cryogenic temperature of 30K (-405°F). Current bonded joint concepts include internal invar plug fittings, external saddle titanium/invar fittings and composite gusset/clip joints all bonded to hybrid composite tubes (75mm square) made with M55J/954-6 and T300/954-6 prepregs. Analytical experience and design work done on metal/composite bonded joints at temperatures below that of liquid nitrogen are limited and important analysis tools, material properties, and failure criteria for composites at cryogenic temperatures are sparse in the literature. Increasing this challenge is the difficulty in testing for these required tools and properties at cryogenic temperatures. To gain confidence in analyzing and designing the ISIM joints, a comprehensive joint development test program has been planned and is currently running. The test program is designed to produce required analytical tools and develop a composite failure criterion for bonded joint strengths at cryogenic temperatures. Finite element analysis is used to design simple test coupons that simulate anticipated stress states in the flight joints; subsequently, the test results are used to correlate the analysis technique for the final design of the bonded joints. In this work, we present an overview of the analysis and test methodology, current results, and working joint designs based on developed techniques and properties.

  1. Temporomandibular Joint Imaging.

    PubMed

    Tamimi, Dania; Jalali, Elnaz; Hatcher, David

    2018-01-01

    The temporomandibular joint (TMJ) is an anatomically and biomechanically complex structure. Understanding how this structure grows and functions is essential to accurate radiographic evaluation. This article discusses the anatomy, function, and growth and development of the TMJ and how growth changes can affect the morphology of the craniofacial structures. Accordingly, the radiographic appearance of the entities that may alter the TMJ are discussed, including developmental, degenerative, inflammatory, and traumatic changes. Both osseous imaging and soft tissue imaging are shown. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. The cyclic fatigue behavior of adhesive joints

    NASA Astrophysics Data System (ADS)

    Kinloch, A. J.; Toh, T.

    1995-06-01

    In the last six months we have: (1) Concentrated our efforts on the fatigue failure of carbon-fiber PEEK/AFl63 lap joints, and in particular we have started to predict the life time of single-lap joints under cyclic fatigue loading. The analysis is based on data obtained from double cantilever beam (DCB) fracture mechanics tests; (2) Further, we have been successful in measuring the rate of crack growth in lap joints during fatigue fracture using ultrasonic scanning; (3) Preliminary test data on the static fracture of glass-fiber reinforced poly(phenylene sulphide) (PPS)/AF163 joints have also been studied; and (4) A comparison has been made in computing the critical strain energy release rate G(sub c) for the glass-fiber PPS/AF163 joints based on the compliance method, beam theory and corrected beam theory. The last method accounts for large non-linear deflections and the associated crack root rotations along with the necessary corrections for the increase in stiffness introduced by the presence of end blocks.

  3. STS-48 ESC image of the MODE-01 Fluid Test Article (FTA) on OV-103's middeck

    NASA Technical Reports Server (NTRS)

    1991-01-01

    An electronic still camera (ESC) closeup shows the STS-48 Middeck Zero ('0') Gravity Dynamics Experiment 01 (MODE-01) Fluid Test Article (FTA) attached to an experimental support module (ESM) located in a forward middeck locker onboard the earth-orbiting Discovery, Orbiter Vehicle (OV) 103. The FTA is a 3.1-cm diameter cylindrical sealed Lexan tank. The FTA electromagnetic actuator has excited the test article sinusoidally, which causes the fluid inside the tank to slosh. These slosh forces, along with other data such as acceleration levels of the entire assembly, are measured by the force balance and recorded in digital form on an optical disk for later ground analysis. Crewmembers were testing the ESC as part of Development Test Objective (DTO) 648, Electronic Still Photography. The digital image was stored on a removable hard disk or small optical disk, and could be converted to a format suitable for downlink transmission. The ESC is making its initial appearance on this Space Shutt

  4. Interfacial microstructure and mechanical properties of brazed aluminum / stainless steel - joints

    NASA Astrophysics Data System (ADS)

    Fedorov, V.; Elßner, M.; Uhlig, T.; Wagner, G.

    2017-03-01

    Due to the demand of mass and cost reduction, joints based on dissimilar metals become more and more interesting. Especially there is a high interest for joints between stainless steel and aluminum, often necessary for example for automotive heat exchangers. Brazing offers the possibilities to manufacture several joints in one step at, in comparison to fusion welding, lower temperatures. In the recent work, aluminum / stainless steel - joints are produced by induction brazing using an AlSi10 filler and a non-corrosive flux. The mechanical properties are determined by tensile shear tests as well as fatigue tests at ambient and elevated temperatures. The microstructure of the brazed joints and the fracture surfaces of the tested samples are investigated by SEM.

  5. Can physical joint simulators be used to anticipate clinical wear problems of new joint replacement implants prior to market release?

    PubMed

    Medley, John B

    2016-05-01

    One of the most important mandates of physical joint simulators is to provide test results that allow the implant manufacturer to anticipate and perhaps avoid clinical wear problems with their new products. This is best done before market release. This study gives four steps to follow in conducting such wear simulator testing. Two major examples involving hip wear simulators are discussed in which attempts had been made to predict clinical wear performance prior to market release. The second one, involving the DePuy ASR implant systems, is chosen for more extensive treatment by making it an illustrative example to explore whether wear simulator testing can anticipate clinical wear problems. It is concluded that hip wear simulator testing did provide data in the academic literature that indicated some risk of clinical wear problems prior to market release of the ASR implant systems. This supports the idea that physical joint simulators have an important role in the pre-market testing of new joint replacement implants. © IMechE 2016.

  6. Diagnostic accuracy of clinical tests of the hip: a systematic review with meta-analysis.

    PubMed

    Reiman, Michael P; Goode, Adam P; Hegedus, Eric J; Cook, Chad E; Wright, Alexis A

    2013-09-01

    Hip Physical Examination (HPE) tests have long been used to diagnose a myriad of intra-and extra-articular pathologies of the hip joint. Useful clinical utility is necessary to support diagnostic imaging and subsequent surgical decision making. Summarise and evaluate the current research and utility on the diagnostic accuracy of HPE tests for the hip joint germane to sports related injuries and pathology. A computer-assisted literature search of MEDLINE, CINHAL and EMBASE databases (January 1966 to January 2012) using keywords related to diagnostic accuracy of the hip joint. This systematic review with meta-analysis utilised the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for the search and reporting phases of the study. Der-Simonian and Laird random effects models were used to summarise sensitivities (SN), specificities (SP), likelihood ratios and diagnostic OR. The employed search strategy revealed 25 potential articles, with 10 demonstrating high quality. Fourteen articles qualified for meta-analysis. The meta-analysis demonstrated that most tests possess weak diagnostic properties with the exception of the patellar-pubic percussion test, which had excellent pooled SN 95 (95% CI 92 to 97%) and good specificity 86 (95% CI 78 to 92%). Several studies have investigated pathology in the hip. Few of the current studies are of substantial quality to dictate clinical decision-making. Currently, only the patellar-pubic percussion test is supported by the data as a stand-alone HPE test. Further studies involving high quality designs are needed to fully assess the value of HPE tests for patients with intra- and extra-articular hip dysfunction.

  7. Integrating Quantitative and Qualitative Results in Health Science Mixed Methods Research Through Joint Displays.

    PubMed

    Guetterman, Timothy C; Fetters, Michael D; Creswell, John W

    2015-11-01

    Mixed methods research is becoming an important methodology to investigate complex health-related topics, yet the meaningful integration of qualitative and quantitative data remains elusive and needs further development. A promising innovation to facilitate integration is the use of visual joint displays that bring data together visually to draw out new insights. The purpose of this study was to identify exemplar joint displays by analyzing the various types of joint displays being used in published articles. We searched for empirical articles that included joint displays in 3 journals that publish state-of-the-art mixed methods research. We analyzed each of 19 identified joint displays to extract the type of display, mixed methods design, purpose, rationale, qualitative and quantitative data sources, integration approaches, and analytic strategies. Our analysis focused on what each display communicated and its representation of mixed methods analysis. The most prevalent types of joint displays were statistics-by-themes and side-by-side comparisons. Innovative joint displays connected findings to theoretical frameworks or recommendations. Researchers used joint displays for convergent, explanatory sequential, exploratory sequential, and intervention designs. We identified exemplars for each of these designs by analyzing the inferences gained through using the joint display. Exemplars represented mixed methods integration, presented integrated results, and yielded new insights. Joint displays appear to provide a structure to discuss the integrated analysis and assist both researchers and readers in understanding how mixed methods provides new insights. We encourage researchers to use joint displays to integrate and represent mixed methods analysis and discuss their value. © 2015 Annals of Family Medicine, Inc.

  8. Integrating Quantitative and Qualitative Results in Health Science Mixed Methods Research Through Joint Displays

    PubMed Central

    Guetterman, Timothy C.; Fetters, Michael D.; Creswell, John W.

    2015-01-01

    PURPOSE Mixed methods research is becoming an important methodology to investigate complex health-related topics, yet the meaningful integration of qualitative and quantitative data remains elusive and needs further development. A promising innovation to facilitate integration is the use of visual joint displays that bring data together visually to draw out new insights. The purpose of this study was to identify exemplar joint displays by analyzing the various types of joint displays being used in published articles. METHODS We searched for empirical articles that included joint displays in 3 journals that publish state-of-the-art mixed methods research. We analyzed each of 19 identified joint displays to extract the type of display, mixed methods design, purpose, rationale, qualitative and quantitative data sources, integration approaches, and analytic strategies. Our analysis focused on what each display communicated and its representation of mixed methods analysis. RESULTS The most prevalent types of joint displays were statistics-by-themes and side-by-side comparisons. Innovative joint displays connected findings to theoretical frameworks or recommendations. Researchers used joint displays for convergent, explanatory sequential, exploratory sequential, and intervention designs. We identified exemplars for each of these designs by analyzing the inferences gained through using the joint display. Exemplars represented mixed methods integration, presented integrated results, and yielded new insights. CONCLUSIONS Joint displays appear to provide a structure to discuss the integrated analysis and assist both researchers and readers in understanding how mixed methods provides new insights. We encourage researchers to use joint displays to integrate and represent mixed methods analysis and discuss their value. PMID:26553895

  9. An arthroscopic safety zone for the medial compartment of the hip joint.

    PubMed

    Lee, Je-Hun; Lee, Jung-Bum; Lee, Nam Seob; Han, Seung Yun; Kim, In-Beom; Han, Seung-Ho

    2015-10-01

    The purpose of this study was to investigate the safety zone without any neurovascular injury to the medial compartment of hip joint through an anatomical method and describe the relationship of the extra-articular anatomic structures from the surface of the hip joint. Thirty-two fresh specimens from 17 adult Korean cadavers (8 males and 9 females, age range 54-79 years at death) were used for this study. For the measurements, the most superolateral point of the pubic symphysis (PS) and prominent point of the anterior superior iliac spine (ASIS) were identified before dissection. The line connecting the PS and ASIS was defined as a reference line and the PS was a starting point for measurements. All 19 variables measured in this study were related to the femoral head, neck, and surrounding neurovascular structures. The variables were measured according to the x- and y-coordinates in relation to the reference line. The femoral head was generally located 39.5-71.0 mm on the x-coordinate and located 33.5-34.6 mm on the y-coordinate. The junction of the femoral neck and body was located at 52.8 mm on the x-coordinate, and 65.3 mm on the y-coordinate. The junction of the femoral head and neck was located at 47.1 mm on the x-coordinate, and 51.4 mm on the y-coordinate. The location of the medial compartment of the hip joint was located from 38.0 to 43.0 % on the x-coordinate and located from 5.1 to 6.5 cm. These results of this study provide detailed anatomy for arthroscopic hip surgeons.

  10. Technical tips to perform safe and effective ultrasound guided steroid joint injections in children.

    PubMed

    Parra, Dimitri A

    2015-01-01

    The aim of this article is to describe the technique used to perform ultrasound guided steroid joint injections in children in a group of joints that can be injected using ultrasound as the only image guidance modality. The technique is described and didactic figures are provided to illustrate key technical concepts. It is very important to be familiar with the sonographic appearance of the pediatric joints and the developing bone when performing ultrasound-guided joint injections in children.

  11. A systematic evaluation of prevalence and diagnostic accuracy of sacroiliac joint interventions.

    PubMed

    Simopoulos, Thomas T; Manchikanti, Laxmaiah; Singh, Vijay; Gupta, Sanjeeva; Hameed, Haroon; Diwan, Sudhir; Cohen, Steven P

    2012-01-01

    The contributions of the sacroiliac joint to low back and lower extremity pain have been a subject of considerable debate and research. It is generally accepted that 10% to 25% of patients with persistent mechanical low back pain below L5 have pain secondary to sacroiliac joint pathology. However, no single historical, physical exam, or radiological feature can definitively establish a diagnosis of sacroiliac joint pain. Based on present knowledge, a proper diagnosis can only be made using controlled diagnostic blocks. The diagnosis and treatment of sacroiliac joint pain continue to be characterized by wide variability and a paucity of the literature. To evaluate the accuracy of diagnostic sacroiliac joint interventions. A systematic review of diagnostic sacroiliac joint interventions. Methodological quality assessment of included studies was performed using Quality Appraisal of Reliability Studies (QAREL). Only diagnostic accuracy studies meeting at least 50% of the designated inclusion criteria were utilized for analysis. Studies scoring less than 50% are presented descriptively and analyzed critically. The level of evidence was classified as good, fair, or poor based on the quality of evidence developed by the United States Preventive Services Task Force (USPSTF). Data sources included relevant literature identified through searches of PubMed and EMBASE from 1966 to December 2011, and manual searches of the bibliographies of known primary and review articles. In this evaluation we utilized controlled local anesthetic blocks using at least 50% pain relief as the reference standard. The evidence is good for the diagnosis of sacroiliac joint pain utilizing controlled comparative local anesthetic blocks. The prevalence of sacroiliac joint pain is estimated to range between 10% and 62% based on the setting; however, the majority of analyzed studies suggest a point prevalence of around 25%, with a false-positive rate for uncontrolled blocks of approximately 20%. The

  12. Strength of laser welded joints of polypropylene composites

    NASA Astrophysics Data System (ADS)

    Votrubec, V.; Hisem, P.; Vinšová, L.; Lukášová, V.

    2017-11-01

    This paper deals with experimental tests of laser welded polypropylene composites. Polymers, such as polypropylene, are often filled with fibres in order to increase their mechanical properties. The welding procedure can also influence material properties nearby weld joints. Therefore the strength of weld joints is lower than strength of primary materials. This effect is proved by realized shear tests. Polymer specimens were filled with 20 % and 40 % of glass fibres and all possible combinations of specimens were welded for experiments. There is also discussed influence of volume fraction of glass fibres in polypropylene on the strength of weld joint.

  13. Flaw Tolerance In Lap Shear Brazed Joints. Part 2

    NASA Technical Reports Server (NTRS)

    Wang, Len; Flom, Yury

    2003-01-01

    This paper presents results of the second part of an on-going effort to gain better understanding of defect tolerance in braze joints. In the first part of this three-part series, we mechanically tested and modeled the strength of the lap joints as a function of the overlap distance. A failure criterion was established based on the zone damage theory, which predicts the dependence of the lap joint shear strength on the overlap distance, based on the critical size of a finite damage zone or an overloaded region in the joint. In this second part of the study, we experimentally verified the applicability of the damage zone criterion on prediction of the shear strength of the lap joint and introduced controlled flaws into the lap joints. The purpose of the study was to evaluate the lap joint strength as a function of flaw size and its location through mechanical testing and nonlinear finite element analysis (FEA) employing damage zone criterion for definition of failure. The results obtained from the second part of the investigation confirmed that the failure of the ductile lap shear brazed joints occurs when the damage zone reaches approximately 10% of the overlap width. The same failure criterion was applicable to the lap joints containing flaws.

  14. Design and fabrication of realistic adhesively bonded joints

    NASA Technical Reports Server (NTRS)

    Shyprykevich, P.

    1983-01-01

    Eighteen bonded joint test specimens representing three different designs of a composite wing chordwise bonded splice were designed and fabricated using current aircraft industry practices. Three types of joints (full wing laminate penetration, two side stepped; midthickness penetration, one side stepped; and partial penetration, scarfed) were analyzed using state of the art elastic joint analysis modified for plastic behavior of the adhesive. The static tensile fail load at room temperature was predicted to be: (1) 1026 kN/m (5860 1b/in) for the two side stepped joint; (2) 925 kN/m (5287 1b/in) for the one side stepped joint; and (3) 1330 kN/m (7600 1b/in) for the scarfed joint. All joints were designed to fail in the adhesive.

  15. Hybrid Al/steel-joints manufactured by ultrasound enhanced friction stir welding (USE-FSW): Process comparison, nondestructive testing and microscopic analysis

    NASA Astrophysics Data System (ADS)

    Thomä, M.; Wagner, G.; Straß, B.; Wolter, B.; Benfer, S.; Fürbeth, W.

    2017-03-01

    The process of friction stir welding (FSW) is an innovative joining technique, which proved its potential in joining dissimilar metals that are poorly fusion weldable. This ability opens a wide range for applications in industrial fields, where weight reduction by partial substitution of conventional materials through lightweight materials is a current central aim. As a consequence of this, the realization of aluminum / steel-joints is of great interest. For this material compound, several friction stir welds were carried out by different researchers for varying Al/steel-joints, whereas the definition of optimal process parameters as well as the increase of mechanical properties was in the focus of the studies. To achieve further improved properties for this dissimilar joint a newly developed hybrid process named “ultrasound enhanced friction stir welding (USE-FSW)” was applied. In this paper the resulting properties of Al/steel-joints using FSW and USE-FSW will be presented and compared. Furthermore, first results by using the nondestructive testing method “computer laminography” to analyze the developed joining area will be shown supplemented by detailed light-microscopic investigations, scanning electron microscopic analysis, and EDX.

  16. Determination of the criterion-related validity of hip joint angle test for estimating hamstring flexibility using a contemporary statistical approach.

    PubMed

    Sainz de Baranda, Pilar; Rodríguez-Iniesta, María; Ayala, Francisco; Santonja, Fernando; Cejudo, Antonio

    2014-07-01

    To examine the criterion-related validity of the horizontal hip joint angle (H-HJA) test and vertical hip joint angle (V-HJA) test for estimating hamstring flexibility measured through the passive straight-leg raise (PSLR) test using contemporary statistical measures. Validity study. Controlled laboratory environment. One hundred thirty-eight professional trampoline gymnasts (61 women and 77 men). Hamstring flexibility. Each participant performed 2 trials of H-HJA, V-HJA, and PSLR tests in a randomized order. The criterion-related validity of H-HJA and V-HJA tests was measured through the estimation equation, typical error of the estimate (TEEST), validity correlation (β), and their respective confidence limits. The findings from this study suggest that although H-HJA and V-HJA tests showed moderate to high validity scores for estimating hamstring flexibility (standardized TEEST = 0.63; β = 0.80), the TEEST statistic reported for both tests was not narrow enough for clinical purposes (H-HJA = 10.3 degrees; V-HJA = 9.5 degrees). Subsequently, the predicted likely thresholds for the true values that were generated were too wide (H-HJA = predicted value ± 13.2 degrees; V-HJA = predicted value ± 12.2 degrees). The results suggest that although the HJA test showed moderate to high validity scores for estimating hamstring flexibility, the prediction intervals between the HJA and PSLR tests are not strong enough to suggest that clinicians and sport medicine practitioners should use the HJA and PSLR tests interchangeably as gold standard measurement tools to evaluate and detect short hamstring muscle flexibility.

  17. A Method for and Issues Associated with the Determination of Space Suit Joint Requirements

    NASA Technical Reports Server (NTRS)

    Matty, Jennifer E.; Aitchison, Lindsay

    2010-01-01

    This joint mobility KC lecture included information from two papers, "A Method for and Issues Associated with the Determination of Space Suit Joint Requirements" and "Results and Analysis from Space Suit Joint Torque Testing," as presented for the International Conference on Environmental Systems in 2009 and 2010, respectively. The first paper discusses historical joint torque testing methodologies and approaches that were tested in 2008 and 2009. The second paper discusses the testing that was completed in 2009 and 2010.

  18. The technology and welding joint properties of hybrid laser-tig welding on thick plate

    NASA Astrophysics Data System (ADS)

    Shenghai, Zhang; Yifu, Shen; Huijuan, Qiu

    2013-06-01

    The technologies of autogenous laser welding and hybrid laser-TIG welding are used on thick plate of high strength lower alloy structural steel 10CrNiMnMoV in this article. The unique advantages of hybrid laser-TIG welding is summarized by comparing and analyzing the process parameters and welding joints of autogenous laser welding laser welding and hybrid laser-TIG welding. With the optimal process parameters of hybrid welding, the good welding joint without visible flaws can be obtained and its mechanical properties are tested according to industry standards. The results show that the hybrid welding technology has certain advantages and possibility in welding thick plates. It can reduce the demands of laser power, and it is significant for lowering the aspect ratio of weld during hybrid welding, so the gas in the molten pool can rise and escape easily while welding thick plates. Therefore, the pores forming tendency decreases. At the same time, hybrid welding enhances welding speed, and optimizes the energy input. The transition and grain size of the microstructure of hybrid welding joint is better and its hardness is higher than base material. Furthermore, its tensile strength and impact toughness is as good as base material. Consequently, the hybrid welding joint can meet the industry needs completely.

  19. Distraction for proximal interphalangeal joint contractures: long-term results.

    PubMed

    Houshian, Shirzad; Jing, Shan Shan; Kazemian, Gholam Hussein; Emami-Moghaddam-Tehrani, Mohammad

    2013-10-01

    To report the medium- to long-term outcomes of joint distraction using a unilateral external fixator in the treatment of chronic post-traumatic proximal interphalangaeal (PIP) joint contractures. Between September 2001 and October 2011, 94 consecutive patients (98 PIP joints) with a mean age of 43 years (range, 17-69 y) were treated with external fixation for chronic flexion deformity of the PIP joint from trauma. The average time from injury to surgery was 48 months (range, 6-84 mo), and the duration of joint distraction was 10 days (range, 7-22 d). Patients were followed for a mean period of 54 months (range, 12-72 mo). The average gain in joint flexion was 25° and in joint extension was 40°. The mean improvement in the active range of movement was 67° (range. 30°-90°). There was no loss of motion on the latest follow-up. Patients younger than 40 years fared slightly better than those older than 40 years. Two patients developed swelling, pain, and erythema during treatment, which resolved upon temporarily stopping the distraction process. There were 12 cases of superficial pin-site infections, which were managed conservatively without serious complications or adverse outcome. External fixation is a simple and effective treatment modality for chronic traumatic PIP joint contractures with good predictable medium- to long-term results. Careful patient selection and monitoring are required. Copyright © 2013 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  20. Numerical analysis and experimental research of the rubber boot of the joint drive vehicle

    NASA Astrophysics Data System (ADS)

    Ziobro, Jan

    2016-04-01

    The article presents many numerical studies and experimental research of the drive rubber boot of the joint drive vehicle. Performance requirements have been discussed and the required coefficients of the mathematical model for numerical simulation have been determined. The behavior of living in MSC.MARC environment was examined. In the analysis the following have been used: hyperplastic two-parameter model of the Mooney-Rivlin material, large displacements procedure, safe contact condition, friction on the sides of the boots. 3D numerical model of the joint bootwas analyzed under influence of the forces: tensile, compressive, centrifugal and angular. Numerous results of studies have been presented. An appropriate test stand was built and comparison of the results of the numerical analysis and the results of experimental studies was made. Numerous requests and recommendations for utilitarian character have been presented.

  1. The effect of additional joint mobilization on neuromuscular performance in individuals with functional ankle instability.

    PubMed

    Shih, Yi-Fen; Yu, Hsiang-Ting; Chen, Wen-Yin; Liao, Kwong-Kum; Lin, Hsiu-Chen; Yang, Yea-Ru

    2018-03-01

    To examine the effects of joint mobilization and exercise training on neuromuscular performance in individuals with functional ankle instability (FAI). A cross-sectional study. Forty five subjects with FAI were randomized into three groups: control (CG, n = 15, 27.9 ± 6.6yr), training (TG, n = 15, 26.9 ± 5.8yr) and mobilization with training group (MTG, n = 15, 26.5 ± 4.8yr). Four weeks of neuromuscular training for TG; neuromuscular training and joint mobilization for MTG. Electromyography of the peroneus longus (PL), tibialis anterior (TA), and soleus (SOL) and the reaching distance of the Y balance test (YBT), dorsiflexion range of motion (DFROM), Cumberland ankle instability tool (CAIT), and global rating scale (GRS). Two-way repeated measures MANOVA were used with the significance level p < .05. MANOVA found significant group by time interactions on posterolateral reaching distance (p = .032), PL activation (p = .006-.03), DFROM (p < .001), CAIT (p < .001) and GRS (p < .001). The post hoc tests indicated significantly improved PL muscle activity and posterolateral reaching distance for MTG compared to TG (p = .004) and CG (p = .006). Joint mobilization resulted in additional benefits on self-reported ankle instability severity, dorsiflexion mobility, and posterolateral balance performance in individuals with FAI, but its effects on general improvement, muscle activation, and other balance tasks remained uncertain. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. An empirical investigation of for-profit and tax-exempt nonprofit hospitals engaged in joint ventures.

    PubMed

    Smith, Pamela C

    2004-01-01

    Joint ventures between nonprofit and for-profit hospitals offer opportunities for collaboration to increase efficiency. These transactions have attracted the attention of the Internal Revenue Service, which may threaten tax-exempt status. This article analyzes inherent financial characteristics of nonprofit hospitals that joint venture with for-profit hospitals and those that choose not to joint venture.

  3. If the results of an article are noteworthy, read the entire article; do not rely on the abstract alone.

    PubMed

    Dal-Ré, R; Castell, M V; García-Puig, J

    2015-11-01

    Clinicians typically update their knowledge by reading articles on the Internet. Easy access to the articles' abstracts and a lack of time to access other information sources creates a risk that therapeutic or diagnostic decisions will be made after reading just the abstracts. Occasionally, however, the abstracts of articles from clinical trials that have not obtained statistically significant differences in the primary study endpoint have reported other positive results, for example, of a secondary endpoint or a subgroup analysis. The article, however, correctly reports all results, including those of the primary endpoint. In the abstract, the safety information of the experimental treatment is usually deficient. The whole article should be read if a clinical decision is to be made. Copyright © 2015 Elsevier España, S.L.U. y Sociedad Española de Medicina Interna (SEMI). All rights reserved.

  4. Strength of Welded Joints in Tubular Members for Aircraft

    NASA Technical Reports Server (NTRS)

    Whittemore, H L; Brueggeman, W C

    1931-01-01

    The object of this investigation is to make available to the aircraft industry authoritative information on the strength, weight, and cost of a number of types of welded joints. This information will, also, assist the aeronautics branch in its work of licensing planes by providing data from which the strength of a given joint may be estimated. As very little material on the strength of aircraft welds has been published, it is believed that such tests made by a disinterested governmental laboratory should be of considerable value to the aircraft industry. Forty joints were welded under procedure specifications and tested to determine their strengths. The weight and time required to fabricate were also measured for each joint.

  5. Finite-Element Analysis of a Mach-8 Flight Test Article Using Nonlinear Contact Elements

    NASA Technical Reports Server (NTRS)

    Richards, W. Lance

    1997-01-01

    A flight test article, called a glove, is required for a Mach-8 boundary-layer experiment to be conducted on a flight mission of the air-launched Pegasus(reg) space booster. The glove is required to provide a smooth, three-dimensional, structurally stable, aerodynamic surface and includes instrumentation to determine when and where boundary-layer transition occurs during the hypersonic flight trajectory. A restraint mechanism has been invented to attach the glove to the wing of the space booster. The restraint mechanism securely attaches the glove to the wing in directions normal to the wing/glove interface surface, but allows the glove to thermally expand and contract to alleviate stresses in directions parallel to the interface surface. A finite-element analysis has been performed using nonlinear contact elements to model the complex behavior of the sliding restraint mechanism. This paper provides an overview of the glove design and presents details of the analysis that were essential to demonstrate the flight worthiness of the wing-glove test article. Results show that all glove components are well within the allowable stress and deformation requirements to satisfy the objectives of the flight research experiment.

  6. Ultrasonic Welding of Thermoplastic Composite Coupons for Mechanical Characterization of Welded Joints through Single Lap Shear Testing.

    PubMed

    Villegas, Irene F; Palardy, Genevieve

    2016-02-11

    This paper presents a novel straightforward method for ultrasonic welding of thermoplastic-composite coupons in optimum processing conditions. The ultrasonic welding process described in this paper is based on three main pillars. Firstly, flat energy directors are used for preferential heat generation at the joining interface during the welding process. A flat energy director is a neat thermoplastic resin film that is placed between the parts to be joined prior to the welding process and heats up preferentially owing to its lower compressive stiffness relative to the composite substrates. Consequently, flat energy directors provide a simple solution that does not require molding of resin protrusions on the surfaces of the composite substrates, as opposed to ultrasonic welding of unreinforced plastics. Secondly, the process data provided by the ultrasonic welder is used to rapidly define the optimum welding parameters for any thermoplastic composite material combination. Thirdly, displacement control is used in the welding process to ensure consistent quality of the welded joints. According to this method, thermoplastic-composite flat coupons are individually welded in a single lap configuration. Mechanical testing of the welded coupons allows determining the apparent lap shear strength of the joints, which is one of the properties most commonly used to quantify the strength of thermoplastic composite welded joints.

  7. Ultrasonic Welding of Thermoplastic Composite Coupons for Mechanical Characterization of Welded Joints through Single Lap Shear Testing

    PubMed Central

    Villegas, Irene F.; Palardy, Genevieve

    2016-01-01

    This paper presents a novel straightforward method for ultrasonic welding of thermoplastic-composite coupons in optimum processing conditions. The ultrasonic welding process described in this paper is based on three main pillars. Firstly, flat energy directors are used for preferential heat generation at the joining interface during the welding process. A flat energy director is a neat thermoplastic resin film that is placed between the parts to be joined prior to the welding process and heats up preferentially owing to its lower compressive stiffness relative to the composite substrates. Consequently, flat energy directors provide a simple solution that does not require molding of resin protrusions on the surfaces of the composite substrates, as opposed to ultrasonic welding of unreinforced plastics. Secondly, the process data provided by the ultrasonic welder is used to rapidly define the optimum welding parameters for any thermoplastic composite material combination. Thirdly, displacement control is used in the welding process to ensure consistent quality of the welded joints. According to this method, thermoplastic-composite flat coupons are individually welded in a single lap configuration. Mechanical testing of the welded coupons allows determining the apparent lap shear strength of the joints, which is one of the properties most commonly used to quantify the strength of thermoplastic composite welded joints. PMID:26890931

  8. Joint Chiefs of Staff > Media > Publications

    Science.gov Websites

    Facebook on Flickr Joint Chiefs Army Chief of Staff Marine Corps Commandant Chief of Naval Operations Air Force Chief of Staff Chief of National Guard Bureau Biographies Directorates Directorates of Management - Upholding Our Oath SEAC's Publications Book | The Noncommissioned Officer and Petty Officer SEAC's Articles

  9. Improving the fatigue resistance of adhesive joints in laminated wood structures

    NASA Technical Reports Server (NTRS)

    Laufenberg, Theodore L.; River, Bryan H.; Murmanis, Lidija L.; Christiansen, Alfred W.

    1988-01-01

    The premature fatigue failure of a laminated wood/epoxy test beam containing a cross section finger joint was the subject of a multi-disciplinary investigation. The primary objectives were to identify the failure mechanisms which occurred during the finger joint test and to provide avenues for general improvements in the design and fabrication of adhesive joints in laminated wood structures.

  10. MRI and CBCT image registration of temporomandibular joint: a systematic review.

    PubMed

    Al-Saleh, Mohammed A Q; Alsufyani, Noura A; Saltaji, Humam; Jaremko, Jacob L; Major, Paul W

    2016-05-10

    The purpose of the present review is to systematically and critically analyze the available literature regarding the importance, applicability, and practicality of (MRI), computerized tomography (CT) or cone-beam CT (CBCT) image registration for TMJ anatomy and assessment. A systematic search of 4 databases; MEDLINE, EMBASE, EBM reviews and Scopus, was conducted by 2 reviewers. An additional manual search of the bibliography was performed. All articles discussing the magnetic resonance imaging MRI and CT or CBCT image registration for temporomandibular joint (TMJ) visualization or assessment were included. Only 3 articles satisfied the inclusion criteria. All included articles were published within the last 7 years. Two articles described MRI to CT multimodality image registration as a complementary tool to visualize TMJ. Both articles used images of one patient only to introduce the complementary concept of MRI-CT fused image. One article assessed the reliability of using MRI-CBCT registration to evaluate the TMJ disc position and osseous pathology for 10 temporomandibular disorder (TMD) patients. There are very limited studies of MRI-CT/CBCT registration to reach a conclusion regarding its accuracy or clinical use in the temporomandibular joints.

  11. Osteoarthritis of the distal interphalangeal joint.

    PubMed

    Kaufmann, Robert A; Lögters, Tim T; Verbruggen, Gust; Windolf, Joachim; Goitz, Robert J

    2010-12-01

    Osteoarthritis occurs with the highest prevalence in the distal interphalangeal joint of the hand and has been divided into an erosive and a nonerosive form. The pathogenesis of the early stages of osteoarthritis is poorly understood, but considerable emphasis has been placed on the role of cartilage and subchondral bone as well as soft tissue structures such as collateral ligaments and tendons. Radiographic evaluation represents the most standardized method to quantify disease progression, with different systems having been developed for defining and grading radiographic features. This current concepts article examines the recent knowledge base regarding the etiology, pathogenesis, and evaluation of osteoarthritis of the distal interphalangeal joint. Copyright © 2010. Published by Elsevier Inc.

  12. Design/Analysis of the JWST ISIM Bonded Joints for Survivability at Cryogenic Temperatures

    NASA Technical Reports Server (NTRS)

    Bartoszyk, Andrew; Johnston, John; Kaprielian, Charles; Kuhn, Jonathan; Kunt, Cengiz; Rodini, Benjamin; Young, Daniel

    2005-01-01

    Contents include the following: JWST/ISIM introduction. Design and analysis challenges for ISIM bonded joints. JWST/ISIM joint designs. Bonded joint analysis. Finite element modeling. Failure criteria and margin calculation. Analysis/test correlation procedure. Example of test data and analysis.

  13. The Role of Bariatric Surgery in the Obese Total Joint Arthroplasty Patient.

    PubMed

    Hooper, Jessica M; Deshmukh, Ajit J; Schwarzkopf, Ran

    2018-07-01

    Although bariatric surgery is a proven means of weight loss and treatment of obesity-related comorbidities in morbidly obese patients, it is not yet clear how it affects outcomes after total joint arthroplasty in this high-risk patient population. This article explores the effects of obesity and bariatric surgery on osteoarthritis and total joint arthroplasty, and also discusses the financial and ethical implications of use of bariatric surgery for risk reduction before total joint arthroplasty. Copyright © 2018 Elsevier Inc. All rights reserved.

  14. Bidirectional transfer between joint and individual actions in a task of discrete force production.

    PubMed

    Masumoto, Junya; Inui, Nobuyuki

    2017-07-01

    The present study examined bidirectional learning transfer between joint and individual actions involving discrete isometric force production with the right index finger. To examine the effects of practice of joint action on performance of the individual action, participants performed a pre-test (individual condition), practice blocks (joint condition), and a post-test (individual condition) (IJI task). To examine the effects of practice of the individual action on performance during the joint action, the participants performed a pre-test (joint condition), practice blocks (individual condition), and a post-test (joint condition) (JIJ task). Whereas one participant made pressing movements with a target peak force of 10% maximum voluntary contraction (MVC) in the individual condition, two participants produced the target force of the sum of 10% MVC produced by each of them in the joint condition. In both the IJI and JIJ tasks, absolute errors and standard deviations of peak force were smaller post-test than pre-test, indicating bidirectional transfer between individual and joint conditions for force accuracy and variability. Although the negative correlation between forces produced by two participants (complementary force production) became stronger with practice blocks in the IJI task, there was no difference between the pre- and post-tests for the negative correlation in the JIJ task. In the JIJ task, the decrease in force accuracy and variability during the individual action did not facilitate complementary force production during the joint action. This indicates that practice performed by two people is essential for complementary force production in joint action.

  15. A preclinical physiological assay to test modulation of knee joint pain in the spinal cord: effects of oxycodone and naproxen.

    PubMed

    Miranda, Jason A; Stanley, Phil; Gore, Katrina; Turner, Jamie; Dias, Rebecca; Rees, Huw

    2014-01-01

    Sensory processing in the spinal cord during disease states can reveal mechanisms for novel treatments, yet very little is known about pain processing at this level in the most commonly used animal models of articular pain. Here we report a test of the prediction that two clinically effective compounds, naproxen (an NSAID) and oxycodone (an opiate), are efficacious in reducing the response of spinal dorsal horn neurons to noxious knee joint rotation in the monosodium iodoacetate (MIA) sensitized rat. The overall objective for these experiments was to develop a high quality in vivo electrophysiology assay to confidently test novel compounds for efficacy against pain. Given the recent calls for improved preclinical experimental quality we also developed and implemented an Assay Capability Tool to determine the quality of our assay and ensure the quality of our results. Spinal dorsal horn neurons receiving input from the hind limb knee joint were recorded in anesthetized rats 14 days after they were sensitized with 1 mg of MIA. Intravenous administered oxycodone and naproxen were each tested separately for their effects on phasic, tonic, ongoing and afterdischarge action potential counts in response to innocuous and noxious knee joint rotation. Oxycodone reduced tonic spike counts more than the other measures, doing so by up to 85%. Tonic counts were therefore designated the primary endpoint when testing naproxen which reduced counts by up to 81%. Both reductions occurred at doses consistent with clinically effective doses for osteoarthritis. These results demonstrate that clinically effective doses of standard treatments for osteoarthritis reduce pain processing measured at the level of the spinal cord for two different mechanisms. The Assay Capability Tool helped to guide experimental design leading to a high quality and robust preclinical assay to use in discovering novel treatments for pain.

  16. A Preclinical Physiological Assay to Test Modulation of Knee Joint Pain in the Spinal Cord: Effects of Oxycodone and Naproxen

    PubMed Central

    Miranda, Jason A.; Stanley, Phil; Gore, Katrina; Turner, Jamie; Dias, Rebecca; Rees, Huw

    2014-01-01

    Sensory processing in the spinal cord during disease states can reveal mechanisms for novel treatments, yet very little is known about pain processing at this level in the most commonly used animal models of articular pain. Here we report a test of the prediction that two clinically effective compounds, naproxen (an NSAID) and oxycodone (an opiate), are efficacious in reducing the response of spinal dorsal horn neurons to noxious knee joint rotation in the monosodium iodoacetate (MIA) sensitized rat. The overall objective for these experiments was to develop a high quality in vivo electrophysiology assay to confidently test novel compounds for efficacy against pain. Given the recent calls for improved preclinical experimental quality we also developed and implemented an Assay Capability Tool to determine the quality of our assay and ensure the quality of our results. Spinal dorsal horn neurons receiving input from the hind limb knee joint were recorded in anesthetized rats 14 days after they were sensitized with 1 mg of MIA. Intravenous administered oxycodone and naproxen were each tested separately for their effects on phasic, tonic, ongoing and afterdischarge action potential counts in response to innocuous and noxious knee joint rotation. Oxycodone reduced tonic spike counts more than the other measures, doing so by up to 85%. Tonic counts were therefore designated the primary endpoint when testing naproxen which reduced counts by up to 81%. Both reductions occurred at doses consistent with clinically effective doses for osteoarthritis. These results demonstrate that clinically effective doses of standard treatments for osteoarthritis reduce pain processing measured at the level of the spinal cord for two different mechanisms. The Assay Capability Tool helped to guide experimental design leading to a high quality and robust preclinical assay to use in discovering novel treatments for pain. PMID:25157947

  17. A model to explain joint patterns found in ignimbrite deposits

    NASA Astrophysics Data System (ADS)

    Tibaldi, A.; Bonali, F. L.

    2018-03-01

    The study of fracture systems is of paramount importance for economic applications, such as CO2 storage in rock successions, geothermal and hydrocarbon exploration and exploitation, and also for a better knowledge of seismogenic fault formation. Understanding the origin of joints can be useful for tectonic studies and for a geotechnical characterisation of rock masses. Here, we illustrate a joint pattern discovered in ignimbrite deposits of South America, which can be confused with conjugate tectonic joint sets but which have another origin. The pattern is probably common, but recognisable only in plan view and before tectonic deformation obscures and overprints it. Key sites have been mostly studied by field surveys in Bolivia and Chile. The pattern is represented by hundreds-of-meters up to kilometre-long swarms of master joints, which show circular to semi-circular geometries and intersections that have "X" and "Y" patterns. Inside each swarm, joints are systematic, rectilinear or curvilinear in plan view, and as much as 900 m long. In section view, they are from sub-vertical to vertical and do not affect the underlying deposits. Joints with different orientation mostly interrupt each other, suggesting they have the same age. This joint architecture is here interpreted as resulting from differential contraction after emplacement of the ignimbrite deposit above a complex topography. The set of the joint pattern that has suitable orientation with respect to tectonic stresses may act to nucleate faults.

  18. Design fabrication and test of graphite/polyimide composite joints and attachments for advanced aerospace vehicles

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Graphite/polyimide (Gr/PI) bolted and bonded joints were investigated. Possible failure modes and the design loads for the four generic joint types are discussed. Preliminary sizing of a type 1 joint, bonded and bolted configuration is described, including assumptions regarding material properties and sizing methodology. A general purpose finite element computer code is described that was formulated to analyze single and double lap joints, with and without tapered adherends, and with user-controlled variable element size arrangements. An initial order of Celion 6000/PMR-15 prepreg was received and characterized.

  19. A small punch test technique for characterizing the elastic modulus and fracture behavior of PMMA bone cement used in total joint replacement.

    PubMed

    Giddings, V L; Kurtz, S M; Jewett, C W; Foulds, J R; Edidin, A A

    2001-07-01

    Polymethylmethacrylate (PMMA) bone cement is used in total joint replacements to anchor implants to the underlying bone. Establishing and maintaining the integrity of bone cement is thus of critical importance to the long-term outcome of joint replacement surgery. The goal of the present study was to evaluate the suitability of a novel testing technique, the small punch or miniaturized disk bend test, to characterize the elastic modulus and fracture behavior of PMMA. We investigated the hypothesis that the crack initiation behavior of PMMA during the small punch test was sensitive to the test temperature. Miniature disk-shaped specimens, 0.5 mm thick and 6.4 mm in diameter, were prepared from PMMA and Simplex-P bone cement according to manufacturers' instructions. Testing was conducted at ambient and body temperatures, and the effect of test temperature on the elastic modulus and fracture behavior was statistically evaluated using analysis of variance. For both PMMA materials, the test temperature had a significant effect on elastic modulus and crack initiation behavior. At body temperature, the specimens exhibited "ductile" crack initiation, whereas at room temperature "brittle" crack initiation was observed. The small punch test was found to be a sensitive and repeatable test method for evaluating the mechanical behavior of PMMA. In light of the results of this study, future small punch testing should be conducted at body temperature.

  20. Influence of the Strength Mismatch of a Narrow Gap Welded Joint of SA508 on the Plastic η Factor

    NASA Astrophysics Data System (ADS)

    Koo, J. M.; Huh, Y.; Seok, C. S.

    2012-11-01

    In this article, the influence of the strength mismatch of a narrow gap welded joint of SA508 on the η factor was evaluated. The η factor is the principal parameter that determines the plastic portion of the J-integral. The specimens for tensile and hardness tests were collected from piping with narrow gap welding and the stress-strain curve and hardness were obtained from those. From these results, the Ramberg-Osgood (R-O) constant was obtained. Also, the finite element analysis was performed with variations in the strength mismatch and the weld width. The η factor equation considering the strength mismatch and the weld width of a narrow gap welded joint was suggested.

  1. Joint and Soft Tissue Injections

    MedlinePlus

    ... TestingRead Article >>Plasma Viral Load TestingInsulin TherapyRead Article >>Insulin Therapy Visit our interactive symptom checker Visit our interactive symptom checker Get Started Related ArticlesPlasma Viral Load TestingRead ... TherapyRead Article >>Drugs, Procedures & DevicesInsulin TherapyThe goal of ...

  2. Thermal Fatigue Study of W/cu Joint

    NASA Astrophysics Data System (ADS)

    Zhang, Fu; Wu, Jihong; Xu, Zengyu; Xu, Ying

    2003-06-01

    HHFC mock-ups with a structure of W/Cu/SS were developed by hot isostatic pressing (HIP). The performance of the W/Cu joint under high heat loads was tested using an electron beam. The size of specimens for heat load tests was 25×25 mm and the size of beam spot on the specimen surface was 22 mm in diameter. During heat load test, the specimens were water-cooled. Thermal fatigue test were conducted at power density of 8.7 MW/m2 with pulse duration of 20 seconds and interval of 20 seconds. After 1000 cycles of tests, no cracks and failure were found in the W/Cu joint. The thermal performance was also investigated in the range of 1 ~ 9 MW/m2.

  3. Prototype test article verification of the Space Station Freedom active thermal control system microgravity performance

    NASA Technical Reports Server (NTRS)

    Chen, I. Y.; Ungar, E. K.; Lee, D. Y.; Beckstrom, P. S.

    1993-01-01

    To verify the on-orbit operation of the Space Station Freedom (SSF) two-phase external Active Thermal Control System (ATCS), a test and verification program will be performed prior to flight. The first system level test of the ATCS is the Prototype Test Article (PTA) test that will be performed in early 1994. All ATCS loops will be represented by prototypical components and the line sizes and lengths will be representative of the flight system. In this paper, the SSF ATCS and a portion of its verification process are described. The PTA design and the analytical methods that were used to quantify the gravity effects on PTA operation are detailed. Finally, the gravity effects are listed, and the applicability of the 1-g PTA test results to the validation of on-orbit ATCS operation is discussed.

  4. Biomechanical evaluation of native acromioclavicular joint ligaments and two reconstruction techniques in the presence of the sternoclavicular joint: A cadaver study.

    PubMed

    Masionis, Povilas; Šatkauskas, Igoris; Mikelevičius, Vytautas; Ryliškis, Sigitas; Bučinskas, Vytautas; Griškevičius, Julius; Martin Oliva, Xavier; Monzó Planella, Mariano; Porvaneckas, Narūnas; Uvarovas, Valentinas

    2017-01-01

    Where is over 100 reconstruction techniques described for acromioclavicular (AC) joint reconstruction. Although, it is not clear whether the presence of the sternoclavicular (SC) joint influences the biomechanical properties of native AC ligaments and reconstruction techniques. The purpose of the present study was to investigate the biomechanical properties of native AC joint ligaments and two reconstruction techniques in cadavers with the SC joint still present. We tested eight fresh-frozen cadaver hemithoraces for superior translation (70 N load) and translation increment after 1000 cycles (loading from 20 to 70 N) in a controlled laboratory study. There were three testing groups created: native ligaments, the single coracoclavicular loop (SCL) technique, and the two coracoclavicular loops (TCL) technique. Superior translation was measured after static loading. Translation increment was calculated as the difference between superior translation after cyclic and static loading. Native AC ligaments showed significantly lower translation than the SCL ( p = 0.023) and TCL ( p = 0.046) groups. The SCL had a significantly lower translation increment than native AC ligaments ( p = 0.028). There was no significant difference between reconstruction techniques in terms of translation ( p = 0.865) and translation increment ( p = 0.113). Native AC joint ligaments had better static properties than both reconstruction techniques and worse dynamic biomechanical properties than the SCL technique. The SCL technique appeared to be more secure than the TCL technique. The presence of the SC joint did not have an observable influence on test results.

  5. Demonstration of movement in the sacroiliac joint using ultrasound

    NASA Astrophysics Data System (ADS)

    Krupinski, Elizabeth A.; Brooks, William J.; Lund, Pamela J.

    1995-05-01

    The goal of this study was to demonstrate quantitatively, using ultrasound (US) recording techniques, the extent of motion of the sacroiliac joint achieved using manual medicine techniques. Initial judgements of perceived (i.e., felt) SI mobility during manual examination were made on 22 subjects. Baseline no movement ultrasound images (static) were obtained of the left and right SI joints at two levels-- posterior-superior-iliac-spine and inferior (PSIS, INF)--and two projections (AP and LAT). Manual medicine spring testing of the SI joint was then performed while ultrasound recordings (on video) were made. The differences between baseline separation of the SI joint and displacement distance during spring testing were measured by six radiologists who typically read US images. Significant movement of at least one SI joint was demonstrated in 91% of the subjects using ultrasound recordings. The extent of movement appeared to corroborate the experience of manual medicine practitioners.

  6. Application of Bionic Design to FRP T-Joints

    NASA Astrophysics Data System (ADS)

    Luo, Guang-Min; Kuo, Chia-Hung

    2017-09-01

    We applied the concepts of bionics to enhance the mechanical strength of fiberglass reinforced plastic T-joints. The failure modes of the designed arthrosis-like and gum-like joints were determined using three-point bending tests and numerical simulations and compared with those of normal T-joints bonded using structural adhesives. In the simulation, we used cohesive elements to simulate the adhesive interface of the structural adhesive. The experimental and simulation results show that the arthrosis-like joint can effectively delay the failure progress and enhance the bonding strength of T-joints, thus confirming that an appropriate bionic design can effectively control the bonding properties of structural adhesives.

  7. Physiological loading of joints prevents cartilage degradation through CITED2

    PubMed Central

    Leong, Daniel J.; Li, Yong H.; Gu, Xiang I.; Sun, Li; Zhou, Zuping; Nasser, Philip; Laudier, Damien M.; Iqbal, Jameel; Majeska, Robert J.; Schaffler, Mitchell B.; Goldring, Mary B.; Cardoso, Luis; Zaidi, Mone; Sun, Hui B.

    2011-01-01

    Both overuse and disuse of joints up-regulate matrix metalloproteinases (MMPs) in articular cartilage and cause tissue degradation; however, moderate (physiological) loading maintains cartilage integrity. Here, we test whether CBP/p300-interacting transactivator with ED-rich tail 2 (CITED2), a mechanosensitive transcriptional coregulator, mediates this chondroprotective effect of moderate mechanical loading. In vivo, hind-limb immobilization of Sprague-Dawley rats up-regulates MMP-1 and causes rapid, histologically detectable articular cartilage degradation. One hour of daily passive joint motion prevents these changes and up-regulates articular cartilage CITED2. In vitro, moderate (2.5 MPa, 1 Hz) intermittent hydrostatic pressure (IHP) treatment suppresses basal MMP-1 expression and up-regulates CITED2 in human chondrocytes, whereas high IHP (10 MPa) down-regulates CITED2 and increases MMP-1. Competitive binding and transcription assays demonstrate that CITED2 suppresses MMP-1 expression by competing with MMP transactivator, Ets-1 for its coactivator p300. Furthermore, CITED2 up-regulation in vitro requires the p38δ isoform, which is specifically phosphorylated by moderate IHP. Together, these studies identify a novel regulatory pathway involving CITED2 and p38δ, which may be critical for the maintenance of articular cartilage integrity under normal physical activity levels.—Leong, D. J., Li, Y. H., Gu, X. I., Sun, L., Zhou, Z., Nasser, P., Laudier, D. M., Iqbal, J., Majeska, R. J., Schaffler, M. B., Goldring, M. B., Cardoso, L., Zaidi, M., Sun, H. B. Physiological loading of joints prevents cartilage degradation through CITED2. PMID:20826544

  8. Investigation of gold embrittlement in connector solder joints

    NASA Technical Reports Server (NTRS)

    Lane, F. L.

    1972-01-01

    An investigation was performed to determine to what extent typical flight connector solder joints may be embrittled by the presence of gold. In addition to mapping of gold content in connector solder joints by an electron microprobe analyzer, metallographic examinations and mechanical tests (thermal shock, vibration, impact and tensile strength) were also conducted. A description of the specimens and tests, a discussion of the data, and some conclusions are presented.

  9. Study of the Peak Shear Strength of a Cement-Filled Hard Rock Joint

    NASA Astrophysics Data System (ADS)

    She, Cheng-Xue; Sun, Fu-Ting

    2018-03-01

    The peak shear strength of a cement-filled hard rock joint is studied by theoretical analysis and laboratory testing. Based on the concept of the shear resistance angle, by combining the statistical method and fractal theory, three new parameters are proposed to characterize the three-dimensional joint morphology, reflecting the effects of the average roughness, multi-scale asperities and the dispersion degree of the roughness distribution. These factors are independent of the measurement scale, and they reflect the anisotropy of the joint roughness. Compressive shear tests are conducted on cement-filled joints. Because joints without cement can be considered special cement-filled joints in which the filling degree of cement is zero, they are also tested. The cement-filled granite joint fails primarily along the granite-cement interfaces. The filling degree of cement controls the joint failure and affects its mechanical behaviour. With a decrease in the filling degree of cement, the joint cohesion decreases; however, the dilatancy angle and the basic friction angle of the interface increase. As the filling degree approaches zero, the cohesion approaches zero, while the dilatancy angle and the basic friction angle increase to those of the joint without cement. A set of formulas is proposed to evaluate the peak shear strength of the joints with and without cement. The formulas are shown to be reasonable by comparison with the tested peak shear strength, and they reflect the anisotropy of the strength. This research deepens the understanding of cement-filled joints and provides a method to evaluate their peak shear strength.

  10. Non-destructive testing techniques based on nonlinear methods for assessment of debonding in single lap joints

    NASA Astrophysics Data System (ADS)

    Scarselli, G.; Ciampa, F.; Ginzburg, D.; Meo, M.

    2015-04-01

    Nonlinear ultrasonic non-destructive evaluation (NDE) methods can be used for the identification of defects within adhesive bonds as they rely on the detection of nonlinear elastic features for the evaluation of the bond strength. In this paper the nonlinear content of the structural response of a single lap joint subjected to ultrasonic harmonic excitation is both numerically and experimentally evaluated to identify and characterize the defects within the bonded region. Different metallic samples with the same geometry were experimentally tested in order to characterize the debonding between two plates by using two surface bonded piezoelectric transducers in pitch-catch mode. The dynamic response of the damaged samples acquired by the single receiver sensor showed the presence of higher harmonics (2nd and 3rd) and subharmonics of the fundamental frequencies. These nonlinear elastic phenomena are clearly due to nonlinear effects induced by the poor adhesion between the two plates. A new constitutive model aimed at representing the nonlinear material response generated by the interaction of the ultrasonic waves with the adhesive joint is also presented. Such a model is implemented in an explicit FE software and uses a nonlinear user defined traction-displacement relationship implemented by means of a cohesive material user model interface. The developed model is verified for the different geometrical and material configurations. Good agreement between the experimental and numerical nonlinear response showed that this model can be used as a simple and useful tool for understanding the quality of the adhesive joint.

  11. Biomechanical testing simulation of a cadaver spine specimen: development and evaluation study.

    PubMed

    Ahn, Hyung Soo; DiAngelo, Denis J

    2007-05-15

    This article describes a computer model of the cadaver cervical spine specimen and virtual biomechanical testing. To develop a graphics-oriented, multibody model of a cadaver cervical spine and to build a virtual laboratory simulator for the biomechanical testing using physics-based dynamic simulation techniques. Physics-based computer simulations apply the laws of physics to solid bodies with defined material properties. This technique can be used to create a virtual simulator for the biomechanical testing of a human cadaver spine. An accurate virtual model and simulation would complement tissue-based in vitro studies by providing a consistent test bed with minimal variability and by reducing cost. The geometry of cervical vertebrae was created from computed tomography images. Joints linking adjacent vertebrae were modeled as a triple-joint complex, comprised of intervertebral disc joints in the anterior region, 2 facet joints in the posterior region, and the surrounding ligament structure. A virtual laboratory simulation of an in vitro testing protocol was performed to evaluate the model responses during flexion, extension, and lateral bending. For kinematic evaluation, the rotation of motion segment unit, coupling behaviors, and 3-dimensional helical axes of motion were analyzed. The simulation results were in correlation with the findings of in vitro tests and published data. For kinetic evaluation, the forces of the intervertebral discs and facet joints of each segment were determined and visually animated. This methodology produced a realistic visualization of in vitro experiment, and allowed for the analyses of the kinematics and kinetics of the cadaver cervical spine. With graphical illustrations and animation features, this modeling technique has provided vivid and intuitive information.

  12. Aft segment dome-to-stiffener factory joint insulation void elimination

    NASA Technical Reports Server (NTRS)

    Jensen, S. K.

    1991-01-01

    Since the detection of voids in the internal insulation of the dome-to-stiffener factory joint of the 15B aft segment, all aft segment dome-to-stiffener factory joints were x-rated and all were found to contain voids. Using a full-scale process simulation article (PSA), the objective was to demonstrate that the proposed changes in the insulation layup and vacuum bagging processes will greatly reduce or eliminate voids without adversely affecting the configuration of performance of the insulation which serves as a primary seal over the factory joint. The PSA-8 aft segment was insulated and cured using standard production processes.

  13. 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.

  14. Joint hypermobility and headache: the glue that binds the two together--part 2.

    PubMed

    Martin, Vincent T; Neilson, Derek

    2014-09-01

    Past studies have reported that connective tissue disorders (CTDs) are more common in patients with specific types of headache disorders. The objectives of this study are (1) to review and critique the clinical studies reporting an association between joint hypermobility, CTDs and headache and (2) to postulate mechanisms though which CTDs might predispose to headache disorders. PubMed was searched for relevant articles with search terms that included joint hypermobility, Ehlers-Danlos syndrome, Marfan syndrome, and specific headache disorders. A narrative review was performed of these articles as well as those identified from the bibliography of these articles. Case reports and case control studies confirm an association between CTDs and migraine, coat-hanger headaches, carotid arterial dissections, intracranial hypotension, Arnold Chiari malformations-type 1, cervical spine disorders, and temporomandibular joint disorders. Observational cross-sectional studies suggest that the prevalence of CTDs is increased in patients with specific types of headache disorders. It is unknown if the CTDs directly cause these headaches disorders or are associated with them through other mechanisms. © 2014 American Headache Society.

  15. Strengthening of defected beam-column joints using CFRP.

    PubMed

    Mahmoud, Mohamed H; Afefy, Hamdy M; Kassem, Nesreen M; Fawzy, Tarek M

    2014-01-01

    This paper presents an experimental study for the structural performance of reinforced concrete (RC) exterior beam-column joints rehabilitated using carbon-fiber-reinforced polymer (CFRP). The present experimental program consists of testing 10 half-scale specimens divided into three groups covering three possible defects in addition to an adequately detailed control specimen. The considered defects include the absence of the transverse reinforcement within the joint core, insufficient bond length for the beam main reinforcement and inadequate spliced implanted column on the joint. Three different strengthening schemes were used to rehabilitate the defected beam-column joints including externally bonded CFRP strips and sheets in addition to near surface mounted (NSM) CFRP strips. The failure criteria including ultimate capacity, mode of failure, initial stiffness, ductility and the developed ultimate strain in the reinforcing steel and CFRP were considered and compared for each group for the control and the CFRP-strengthened specimens. The test results showed that the proposed CFRP strengthening configurations represented the best choice for strengthening the first two defects from the viewpoint of the studied failure criteria. On the other hand, the results of the third group showed that strengthening the joint using NSM strip technique enabled the specimen to outperform the structural performance of the control specimen while strengthening the joints using externally bonded CFRP strips and sheets failed to restore the strengthened joints capacity.

  16. Prevalence of Y-chromosome sequences and gonadoblastoma in Turner syndrome

    PubMed Central

    de Marqui, Alessandra Bernadete Trovó; da Silva-Grecco, Roseane Lopes; Balarin, Marly Aparecida Spadotto

    2016-01-01

    Abstract Objective: To assess the prevalence of Y-chromosome sequences and gonadoblastoma in patients with Turner syndrome (TS) using molecular techniques. Data source: A literature search was performed in Pubmed, limiting the period of time to the years 2005–2014 and using the descriptors: TS and Y sequences (n=26), and TS and Y-chromosome material (n=27). The inclusion criteria were: articles directly related to the subject and published in English or Portuguese. Articles which did not meet these criteria and review articles were excluded. After applying these criteria, 14 papers were left. Data synthesis: The main results regarding the prevalence of Y-chromosome sequences in TS were: (1) about 60% of the studies were conducted by Brazilian researchers; (2) the prevalence varied from 4.6 to 60%; (3) the most frequently investigated genes were SRY, DYZ3 and TSPY; (4) seven studies used only polymerase chain reaction, while in the remaining seven it was associated with FISH. Nine of the 14 studies reported gonadectomy and gonadoblastoma. The highest prevalence of gonadoblastoma (33%) was found in two studies. In five out of the nine papers evaluated the prevalence of gonadoblastoma was 10–25%; in two of them it was zero. Conclusions: According to these data, molecular analysis to detect Y-chromosome sequences in TS patients is indicated, regardless of their karyotype. In patients who test positive for these sequences, gonadoblastoma needs to be investigated. PMID:26525685

  17. Modelling of the Human Knee Joint Supported by Active Orthosis

    NASA Astrophysics Data System (ADS)

    Musalimov, V.; Monahov, Y.; Tamre, M.; Rõbak, D.; Sivitski, A.; Aryassov, G.; Penkov, I.

    2018-02-01

    The article discusses motion of a healthy knee joint in the sagittal plane and motion of an injured knee joint supported by an active orthosis. A kinematic scheme of a mechanism for the simulation of a knee joint motion is developed and motion of healthy and injured knee joints are modelled in Matlab. Angles between links, which simulate the femur and tibia are controlled by Simulink block of Model predictive control (MPC). The results of simulation have been compared with several samples of real motion of the human knee joint obtained from motion capture systems. On the basis of these analyses and also of the analysis of the forces in human lower limbs created at motion, an active smart orthosis is developed. The orthosis design was optimized to achieve an energy saving system with sufficient anatomy, necessary reliability, easy exploitation and low cost. With the orthosis it is possible to unload the knee joint, and also partially or fully compensate muscle forces required for the bending of the lower limb.

  18. Effect of arthrocentesis plus platelet-rich plasma and platelet-rich plasma alone in the treatment of temporomandibular joint osteoarthritis: A retrospective matched cohort study (A STROBE-compliant article).

    PubMed

    Lin, Shang-Lun; Tsai, Chiang-Chin; Wu, Shang-Liang; Ko, Shun-Yao; Chiang, Wei-Fan; Yang, Jung Wu

    2018-04-01

    Although the research on using platelet-rich plasma (PRP) for temporomandibular joint osteoarthritis (TMJ-OA) has advanced, no unified standards exist for determining the joint use of arthrocentesis and the injection dose and frequency of PRP. This study aimed to compare the efficacy of 2 TMJ-OA treatment approaches, arthrocentesis plus platelet-rich plasma (A+PRP) and PRP alone, and attempted to provide another potential treatment option with a single injection of 2 mL of high-concentration and high-purity PRP.This retrospective matched cohort study enrolled 208 patients who were treated for temporomandibular disorders (TMDs) in the Department of Oral and Maxillofacial Surgery of Tainan Sin-Lau Hospital between August of 2013 and January of 2016, from which 90 patients were selected for the final analysis. The predictor variables were treatment outcome indicators, including joint crepitus sounds, TMD-associated headache, jaw range of motion <6 mm, myofascial pain with referral, temporomandibular joint (TMJ) arthralgia, pain when chewing most foods, and maximum assisted opening (MAO). The data were analyzed using χ tests, t tests, and multiple regression analyses.Among the 90 patients, 30 were assigned into the A+PRP group, and 60 were included in the PRP group. A matching method was used to ensure no statistically significant differences in the categorical and continuous variables between the 2 groups. After treatment, both the A+PRP and PRP groups showed improvements in TMJ-OA. The 2 treatment groups did not show statistically significant differences in the symptom improvement rates of joint crepitus sounds, reparative remodeling, and TMJ arthralgia. However, compared with PRP alone, the A+PRP treatment demonstrated superior performance in improving TMD-associated headache, jaw range of motion <6 mm, myofascial pain with referral, and pain when chewing most foods.Both A+PRP and PRP treatments can effectively improve multiple symptoms of TMJ-OA. Based on the

  19. The Validity and Responsiveness of Isometric Lower Body Multi-Joint Tests of Muscular Strength: a Systematic Review.

    PubMed

    Drake, David; Kennedy, Rodney; Wallace, Eric

    2017-12-01

    Researchers and practitioners working in sports medicine and science require valid tests to determine the effectiveness of interventions and enhance understanding of mechanisms underpinning adaptation. Such decision making is influenced by the supportive evidence describing the validity of tests within current research. The objective of this study is to review the validity of lower body isometric multi-joint tests ability to assess muscular strength and determine the current level of supporting evidence. Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were followed in a systematic fashion to search, assess and synthesize existing literature on this topic. Electronic databases such as Web of Science, CINAHL and PubMed were searched up to 18 March 2015. Potential inclusions were screened against eligibility criteria relating to types of test, measurement instrument, properties of validity assessed and population group and were required to be published in English. The Consensus-based Standards for the Selection of health Measurement Instruments (COSMIN) checklist was used to assess methodological quality and measurement property rating of included studies. Studies rated as fair or better in methodological quality were included in the best evidence synthesis. Fifty-nine studies met the eligibility criteria for quality appraisal. The ten studies that rated fair or better in methodological quality were included in the best evidence synthesis. The most frequently investigated lower body isometric multi-joint tests for validity were the isometric mid-thigh pull and isometric squat. The validity of each of these tests was strong in terms of reliability and construct validity. The evidence for responsiveness of tests was found to be moderate for the isometric squat test and unknown for the isometric mid-thigh pull. No tests using the isometric leg press met the criteria for inclusion in the best evidence synthesis. Researchers and

  20. Fixed Base Modal Survey of the MPCV Orion European Service Module Structural Test Article

    NASA Technical Reports Server (NTRS)

    Winkel, James P.; Akers, J. C.; Suarez, Vicente J.; Staab, Lucas D.; Napolitano, Kevin L.

    2017-01-01

    Recently, the MPCV Orion European Service Module Structural Test Article (E-STA) underwent sine vibration testing using the multi-axis shaker system at NASA GRC Plum Brook Station Mechanical Vibration Facility (MVF). An innovative approach using measured constraint shapes at the interface of E-STA to the MVF allowed high-quality fixed base modal parameters of the E-STA to be extracted, which have been used to update the E-STA finite element model (FEM), without the need for a traditional fixed base modal survey. This innovative approach provided considerable program cost and test schedule savings. This paper documents this modal survey, which includes the modal pretest analysis sensor selection, the fixed base methodology using measured constraint shapes as virtual references and measured frequency response functions, and post-survey comparison between measured and analysis fixed base modal parameters.

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